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Sample records for miscible flood processes

  1. Scale-up of miscible flood processes

    SciTech Connect

    Orr, F.M. Jr.

    1992-05-01

    Results of a wide-ranging investigation of the scaling of the physical mechanisms of miscible floods are reported. Advanced techniques for analysis of crude oils are considered in Chapter 2. Application of supercritical fluid chromatography is demonstrated for characterization of crude oils for equation-of-state calculations of phase equilibrium. Results of measurements of crude oil and phase compositions by gas chromatography and mass spectrometry are also reported. The theory of development of miscibility is considered in detail in Chapter 3. The theory is extended to four components, and sample solutions for a variety of gas injection systems are presented. The analytical theory shows that miscibility can develop even though standard tie-line extension criteria developed for ternary systems are not satisfied. In addition, the theory includes the first analytical solutions for condensing/vaporizing gas drives. In Chapter 4, methods for simulation of viscous fingering are considered. The scaling of the growth of transition zones in linear viscous fingering is considered. In addition, extension of the models developed previously to three dimensions is described, as is the inclusion of effects of equilibrium phase behavior. In Chapter 5, the combined effects of capillary and gravity-driven crossflow are considered. The experimental results presented show that very high recovery can be achieved by gravity segregation when interfacial tensions are moderately low. We argue that such crossflow mechanisms are important in multicontact miscible floods in heterogeneous reservoirs. In addition, results of flow visualization experiments are presented that illustrate the interplay of crossflow driven by gravity with that driven by viscous forces.

  2. Scale-up of miscible flood processes. Annual report

    SciTech Connect

    Orr, F.M. Jr.

    1992-05-01

    Results of a wide-ranging investigation of the scaling of the physical mechanisms of miscible floods are reported. Advanced techniques for analysis of crude oils are considered in Chapter 2. Application of supercritical fluid chromatography is demonstrated for characterization of crude oils for equation-of-state calculations of phase equilibrium. Results of measurements of crude oil and phase compositions by gas chromatography and mass spectrometry are also reported. The theory of development of miscibility is considered in detail in Chapter 3. The theory is extended to four components, and sample solutions for a variety of gas injection systems are presented. The analytical theory shows that miscibility can develop even though standard tie-line extension criteria developed for ternary systems are not satisfied. In addition, the theory includes the first analytical solutions for condensing/vaporizing gas drives. In Chapter 4, methods for simulation of viscous fingering are considered. The scaling of the growth of transition zones in linear viscous fingering is considered. In addition, extension of the models developed previously to three dimensions is described, as is the inclusion of effects of equilibrium phase behavior. In Chapter 5, the combined effects of capillary and gravity-driven crossflow are considered. The experimental results presented show that very high recovery can be achieved by gravity segregation when interfacial tensions are moderately low. We argue that such crossflow mechanisms are important in multicontact miscible floods in heterogeneous reservoirs. In addition, results of flow visualization experiments are presented that illustrate the interplay of crossflow driven by gravity with that driven by viscous forces.

  3. Scale-up of miscible flood processes for heterogeneous reservoirs. Quarterly report, April 1, 1994--June 30, 1994

    SciTech Connect

    Orr, F.M. Jr.

    1994-07-01

    The current project is a systematic research effort to quantify relationships between process mechanisms that can lead to improved recovery from gas injection processes performed in heterogeneous Class 1 and Class 2 reservoirs. It will provide a rational basis for the design of displacement processes that take advantage of crossflow due to capillary, gravity and viscous forces to offset partially the adverse effects of heterogeneity. In effect, the high permeability zones are used to deliver fluid by crossflow to zones that would otherwise be flooded only very slowly. Thus, the research effort is divided into five areas: (a) Development of miscibility in multicomponent systems, (b) Design estimates for nearly miscible displacements, (c) Design of miscible floods for fractured reservoirs (d), Compositional flow visualization experiments, and (e) Simulation of near-miscible flow in heterogeneous systems. The status of the research effort in each area is reviewed briefly in the following section.

  4. Scale-up of miscible flood processes for heterogeneous reservoirs. Final report

    SciTech Connect

    Orr, F.M. Jr.

    1996-04-01

    Results of a wide-ranging investigation of the scaling of gas injection processes are reported. The research examines how the physical mechanisms at work during a gas injection project interact to determine process performance. In particular, the authors examine: the interactions of equilibrium phase behavior and two-phase flow that determine local displacement efficiency and minimum miscibility pressure, the combined effects of viscous fingering, gravity segregation and heterogeneity that control sweep efficiency in 2- and 3-dimensional porous media, the use of streamtube/streamline methods to create very efficient simulation technique for multiphase compositional displacements, the scaling of viscous, capillary and gravity forces for heterogeneous reservoirs, and the effects of the thin films and spreading behavior on three-phase flow. The following key results are documented: rigorous procedures for determination of minimum miscibility pressure (MMP) or minimum miscibility enrichment (MME) for miscibility have been developed for multicomponent systems; the complex dependence of MMP`s for nitrogen/methane floods on oil and injection gas composition observed experimentally is explained for the first time; the presence of layer-like heterogeneities strongly influences the interplay of gravity segregation and viscous fingering, as viscous fingers adapt to preferential flow paths and low permeability layers restrict vertical flow; streamtube/streamline simulation techniques are demonstrated for a variety of injection processes in 2 and 3 dimensions; quantitative scaling estimates for the transitions from capillary-dominated to gravity-dominated to viscous-dominated flows are reported; experimental results are given that demonstrate that high pressure CO{sub 2} can be used to generate low IFT gravity drainage in fractured reservoirs if fractures are suitably connected; and the effect of wetting and spreading behavior on three-phase flow is described. 209 refs.

  5. Scale-up of miscible flood processes for heterogeneous reservoirs. Quarterly report, 1 January--31 March 1994

    SciTech Connect

    Orr, F.M. Jr.

    1994-04-01

    The current project is a systematic research effort aimed at quantifying relationships between process mechanisms that can lead to improved recovery from gas injection processes performed in heterogeneous Class 1 and Class 2 reservoirs. It will provide a rational basis for the design of displacement processes that take advantage of crossflow due to capillary, gravity and viscous forces to offset partially the adverse effects of heterogeneity. In effect, the high permeability zones are used to deliver fluid by crossflow to zones that would otherwise be flooded only very slowly. Thus, the research effort is divided into five areas: Development of miscibility in multicomponent systems; design estimates for nearly miscible displacements; design of miscible floods for fractured reservoirs; compositional flow visualization experiments; simulation of near-miscible flow in heterogeneous systems. The status of the research effort in each area is reviewed briefly in the following section. From this work, we can make the following conclusions: (1) We demonstrated theoretically and experimentally that a linear combination of gravity and viscous forces can be used to correlate residual nonwetting phase saturations for both gravity-favorable and gravity-unfavorable displacements. (2) When gravity forces are comparable to or larger than the viscous forces) gravity unfavorable displacements have significantly higher residual nonwetting phase saturation than gravity-favorable displacements. (3) Because soils have much higher permeabilities than oil reservoirs, gravity effects on residual nonwetting phase saturations are much more significant in spilled-oil clean-up than in oil recovery processes. (4) The effective correlation length for a percolation process can be related to a linear combination of the gravity and viscous forces.

  6. Scale-up of miscible flood processes. Quarterly report, July 1, 1993--September 30, 1993

    SciTech Connect

    Orr, F.M. Jr.

    1993-12-31

    Progress is reported for a comprehensive investigation of the scaling behavior of gas injection processes in heterogeneous reservoirs. The interplay of phase behavior, viscous fingering, gravity segregation, capillary imbibition and drainage, and reservoir heterogeneity is examined in a series of simulations and experiments. Compositional and first-contact miscible simulations of viscous fingering and gravity segregation are compared to show that the two techniques can give very different results. Also, analyzed are two-dimensional and three-dimensional flows in which gravity segregation and viscous fingering interact. The simulations show that 2D and 3D flows can differ significantly. A comparison of analytical solutions for three-component two-phase flow with experimental results for oil/water/alcohol systems is reported. While the experiments and theory show reasonable agreement, some differences remain to be explained. The scaling behavior of the interaction of gravity segregation and capillary forces is investigated through simulations and through scaling arguments based on analysis of the differential equations. The simulations show that standard approaches do not agree well with results of low IFT displacements. The scaling analyses, however, reveal flow regimes where capillary, gravity, or viscous forces dominate the flow.

  7. Factors affecting miscible flooding dispersion coefficients

    SciTech Connect

    Yellig, W.F.; Baker, L.E.

    1980-01-01

    Miscible solvent slug size, and therefore cost, is dependent on the mixing or dispersion taking place in the reservoir. Fluid mixing also can be important in the interpretation of laboratory simulations of miscible floods. An experimental program was conducted to study the effects of velocity, viscosity ratio, rock type, and core length on dispersion (mixing) coefficients measured in short cores, with the objective of scaling laboratory measurements to field systems. Statistical analysis of the results of the tests, matched with the capacitance-dispersion (dead-end pore volume) model, shows that an effective dispersion coefficient derived from the model is the most consistent measure of mixing in the systems studied. Viscosity ratios differing by + 4% from unity had no significant effect on the effective dispersion coefficient. The effect of system length on the effective dispersion coefficient is shown.

  8. Scale-up of miscible flood processes for heterogeneous reservoirs. Second annual report

    SciTech Connect

    Orr, F.M. Jr.

    1995-03-01

    Progress is reported for a comprehensive investigation of the scaling behavior of gas injection processes in heterogeneous reservoirs. The interplay of phase behavior, viscous fingering, gravity segregation, capillary imbibition and drainage, and reservoir heterogeneity is examined in a series of simulations and experiments. Use of streamtube to model multiphase flow is demonstrated to be a fast and accurate approach for displacements that are dominated by reservoir heterogeneity. The streamtube technique is particularly powerful for multiphase compositional displacements because it represents the effects of phase behavior with a one-dimensional flow and represents the effects of heterogeneity through the locations of streamtubes. A new approach for fast calculations of critical tie-lines directly from criticality conditions is reported. A global triangular structure solution for four-component flow systems, whose tie-lies meet at the edge of a quaternary phase diagram or lie in planes is presented. Also demonstrated is the extension of this solution to multicomponent systems under the same assumptions. The interplay of gravity, capillary and viscous forces on final residual oil saturation is examined experimentally and theoretically. The analysis of vertical equilibrium conditions for three-phase gravity drainage shows that almost all oil can be recovered from the top part of a reservoir. The prediction of spreading and stability of thin film is performed to investigate three-phase gravity drainage mechanisms. Finally, experimental results from gravity drainage of crude oil in the presence of CO{sub 2} suggest that gravity drainage could be an efficient oil recovery process for vertically fractured reservoirs.

  9. Scale-up of miscible flood processes for heterogeneous reservoirs. 1993 annual report

    SciTech Connect

    Orr, F.M. Jr.

    1994-05-01

    Progress is reported for a comprehensive investigation of the scaling behavior of gas injection processes in heterogeneous reservoirs. The interplay of phase behavior, viscous fingering, gravity segregation, capillary imbibition and drainage, and reservoir heterogeneity is examined in a series of simulations and experiments. Compositional and first-contact miscable simulations of viscous fingering and gravity segregation are compared to show that the two techniques can give very different results. Also, analyzed are two-dimensional and three-dimensional flows in which gravity segregation and viscous fingering interact. The simulations show that 2D and 3D flows can differ significantly. A comparison of analytical solutions for three-component two-phase flow with experimental results for oil/water/alcohol systems is reported. While the experiments and theory show reasonable agreement, some differences remain to be explained. The scaling behavior of the interaction of gravity segregation and capillary forces is investigated through simulations and through scaling arguments based on analysis of the differential equations. The simulations show that standard approaches do not agree well with results of low IFT displacements. The scaling analyses, however, reveal flow regimes where capillary, gravity, or viscous forces dominate the flow.

  10. Improved Efficiency of Miscible CO(2) Floods and Enhanced Prospects for CO(2) Flooding Heterogeneous Reservoirs.

    SciTech Connect

    Grigg, R.B.; Schechter, D.S.

    1997-08-01

    The overall goal of this project was to improve the efficiency of miscible C0{sub 2} floods and enhance the prospects for flooding heterogeneous reservoirs. This objective was accomplished through experimental and modeling research in three task areas: (1) foams for selective mobility control in heterogeneous reservoirs,( 2) reduction of the amount of C0{sub 2} required in C0{sub 2} floods, and (3) low IFT processe and the possibility of C0{sub 2} flooding in fractured reservoirs. This report provides results from the three-year project for each of the three task areas.

  11. Improved Efficiency of Miscible CO2 Floods and Enhanced Prospects for CO2 Flooding Heterogeneous Reservoirs

    SciTech Connect

    Grigg, Reid B.; Schechter, David S.

    1999-10-15

    The goal of this project is to improve the efficiency of miscible CO2 floods and enhance the prospects for flooding heterogeneous reservoirs. This report provides results of the second year of the three-year project that will be exploring three principles: (1) Fluid and matrix interactions (understanding the problems). (2) Conformance control/sweep efficiency (solving the problems. 3) Reservoir simulation for improved oil recovery (predicting results).

  12. Magnetic resonance imaging study on near miscible supercritical CO2 flooding in porous media

    NASA Astrophysics Data System (ADS)

    Song, Yongchen; Zhu, Ningjun; Zhao, Yuechao; Liu, Yu; Jiang, Lanlan; Wang, Tonglei

    2013-05-01

    CO2 flooding is one of the most popular secondary or tertiary recoveries for oil production. It is also significant for studying the mechanisms of the two-phase and multiphase flow in porous media. In this study, an experimental study was carried out by using magnetic resonance imaging technique to examine the detailed effects of pressure and rates on CO2/decane flow in a bead-pack porous media. The displacing processes were conducted under various pressures in a region near the minimum miscibility pressure (the system tuned from immiscible to miscible as pressure is increasing in this region) and the temperature of 37.8 °C at several CO2 injection volumetric rates of 0.05, 0.10, and 0.15 ml/min (or linear rates of 3.77, 7.54, and 11.3 ft/day). The evolution of the distribution of decane and the characteristics of the two phase flow were investigated and analyzed by considering the pressure and rate. The area and velocity of the transition zone between the two phases were calculated and analyzed to quantify mixing. The area of transition zone decreased with pressure at near miscible region and a certain injection rate and the velocity of the transition zone was always less than the "volumetric velocity" due to mutual solution and diffusion of the two phases. Therefore, these experimental results give the fundamental understanding of tertiary recovery processes at near miscible condition.

  13. The tertiary extension of the Wizard Lake D-3A pool miscible flood

    SciTech Connect

    Backmeyer, L.A.; Guise, D.R.; Mac Donell, P.E.; Nute, A.J.

    1984-09-01

    A tertiary extension of the existing secondary hydrocarbon miscible flood in the Wizard Lake D-3A Pool was implemented in October, 1983. The extension will result in the oil-water contact being lowered 22.6 meters (74.1 feet) to allow miscible displacement of the residual oil in the water flushed portion of the reef. This water flushed zone was formed when the oil-water contact rose during primary depletion of the reservoir from discovery in 1951 until the implementation of the secondary miscible flood in 1969, and also during the repressuring phase of the secondary miscible flood. Ultimate recovery from the pool is expected to be 59 539 10/sup 3/m/sup 3/ (374.49 MMSTB) or 95.95 percent of the original oil-in-place; which is 4 531 10/sup 3/m/sup 3/ (28.50 MMSTB) higher than the secondary miscible flood and 18 583 10/sup 3/m/sup 3/ (116.88 MMSTB) more than under primary depletion. This paper reviews the implementation and monitoring of the tertiary extension of the miscible flood and also the performance of the pool to January 1, 1984.

  14. Design and evaluation of a gravity-stable, miscible CO/sub 2/-solvent flood, Bay St. Elaine Field

    SciTech Connect

    Nute, A.J.

    1983-03-01

    A gravity-stable miscible CO/sub 2/-solvent flood is underway in the Bay St. Elaine Field, South Louisiana. A 33% pore volume CO/sub 2/-solvent slug was injected into a dipping water drive reservoir and is being pushed downdip by the injection of nitrogen gas. The CO/sub 2/ solvent selected for this tertiary flood was tailored by the addition of methane and n-butane to the carbon dioxide. This CO/sub 2/-solvent provides the density difference required to complete a gravity-stable flood within the desired time period and also satisfies the minimum miscibility pressure requirements at reservoir conditions. The paper presents laboratory experimental work performed and process design work required to undertake this type of enhanced recovery project. The results obtained from slim tube tests to determine the CO/sub 2/-solvent composition are presented as well as results of 12-foot sand pack displacement tests to evaluate the recovery efficiency of the selected CO/sub 2/-solvent. Procedures used to determine the mixing zone lengths needed for CO/sub 2/-solvent slug design are discussed along with the method of calculating critical velocity. Pressure pulse tests conducted to improve reservoir definition within the project area are reviewed. In situ residual oil saturations for the unconsolidated sand determined from pressure cores, log-injectlog water flood tests, single well partitioning tracer tests, and open hole well logs are presented. Field injection and current production data are also analyzed.

  15. Origin of Scale-Dependent Dispersivity and Its Implications For Miscible Gas Flooding

    SciTech Connect

    Steven Bryant; Russ Johns; Larry Lake; Thomas Harmon

    2008-09-30

    Dispersive mixing has an important impact on the effectiveness of miscible floods. Simulations routinely assume Fickian dispersion, yet it is well established that dispersivity depends on the scale of measurement. This is one of the main reasons that a satisfactory method for design of field-scale miscible displacement processes is still not available. The main objective of this project was to improve the understanding of the fundamental mechanisms of dispersion and mixing, particularly at the pore scale. To this end, microsensors were developed and used in the laboratory to measure directly the solute concentrations at the scale of individual pores; the origin of hydrodynamic dispersion was evaluated from first principles of laminar flow and diffusion at the grain scale in simple but geometrically completely defined porous media; techniques to use flow reversal to distinguish the contribution to dispersion of convective spreading from that of true mixing; and the field scale impact of permeability heterogeneity on hydrodynamic dispersion was evaluated numerically. This project solved a long-standing problem in solute transport in porous media by quantifying the physical basis for the scaling of dispersion coefficient with the 1.2 power of flow velocity. The researchers also demonstrated that flow reversal uniquely enables a crucial separation of irreversible and reversible contributions to mixing. The interpretation of laboratory and field experiments that include flow reversal provides important insight. Other advances include the miniaturization of long-lasting microprobes for in-situ, pore-scale measurement of tracers, and a scheme to account properly in a reservoir simulator (grid-block scale) for the contributions of convective spreading due to reservoir heterogeneity and of mixing.

  16. Mobility control experience in the Joffre Viking miscible CO[sub 2] flood

    SciTech Connect

    Luhning, R.W. ); Stephenson, D.J.; Graham, A.G.

    1993-08-01

    This paper discusses mobility control in the Joffre Viking field miscible CO[sub 2] flood. Since 1984, three injection strategies have been tried: water-alternating-CO[sub 2] (WACO[sub 2]), continuous CO[sub 2], and simultaneous CO[sub 2] and water. The studies showed that simultaneous injection results in the best CO[sub 2] conformance. CO[sub 2]-foam injection has also been investigated.

  17. Performance review of Brazeau River Nisku dry-gas miscible-flood projects

    SciTech Connect

    Lee, J.I.; Jerhoff, T.F. ); Astete, E.L.

    1994-02-01

    This paper reviews 10 years of dry-gas miscible-flood operations in three Brazeau River Nisku pinnacle reefs in Alberta. In addition, actual pool performance is compared with the original black-oil-model simulation forecasts. Through June 1991, the pools recovered 50% to 70% of original oil in place (OOIP), exceeding estimated waterflood recovery for each pool. Ultimate recoveries are expected to 60% to 80% of OOIP, the range originally predicted.

  18. Scale-up of miscible flood processes

    SciTech Connect

    Orr, F.M.

    1991-06-01

    This report describes recent progress in a research effort to quantify the scaling of interactions of phase behavior of multicomponent mixtures with unstable flow in heterogeneous porous media. Results are presented in three areas: Phase behavior, fluid properties and characterization of crude oils; interactions of phase behavior and flow; viscous fingering and reservoir heterogeneity. In the first area, results of phase behavior experiments are reported for mixtures of CO{sub 2} with crude oil from the Means field. Detailed analyses of phase compositions are also reported for samples taken during the PVT experiments. Also reported are results of an investigation of crude oil compositions and phase compositions by gas chromatography combined with mass spectrometry. In the second area, the first detailed comparison is reported for displacements with and without volume change as components change phase. The solutions described were obtained by the method of characteristics. Also described is a transformation that allows radial flow solutions to be obtained from the linear solutions presented previously. Results of experiments and numerical computations that described the growth of viscous fingers are described in the third area. Results and simulations show clearly that even mild permeability heterogeneity can have a dramatic effect on the form and location of viscous fingers. They also show that the simulations reproduce with good accuracy the transition from flow dominated by viscous forces to flow dominated by the permeability distribution. The agreement between simulation and experiment is good enough that the particle-tracking simulation approach can be used with confidence to explore scaling questions. 54 refs., 126 figs., 23 tabs.

  19. Improved efficiency of miscible CO{sub 2} floods and enhanced prospects for CO{sub 2} flooding heterogeneous reservoirs. Annual report, April 14, 1994--April 13, 1995

    SciTech Connect

    Grigg, R.; Heller, J.; Schechter, D.

    1995-09-01

    The overall goal of this project is to improve the efficiency of miscible CO{sub 2} floods and enhance the prospects for flooding heterogeneous reservoirs. This objective is being accomplished by extending experimental research in three task areas: (1) foams for selective mobility control in heterogeneous reservoirs, (2) reduction of the amount of CO{sub 2} required in CO{sub 2} floods, and (3) miscible CO{sub 2} flooding in fractured reservoirs. This report provides results of the first year of the three-year project for each of the three task areas.

  20. FIELD DEMONSTRATION OF CARBON DIOXIDE MISCIBLE FLOODING IN THE LANSING-KANSAS CITY FORMATION, CENTRAL KANSAS

    SciTech Connect

    Alan Byrnes; G. Paul Willhite; Don Green; Martin Dubois; Richard Pancake; Timothy Carr; W. Lynn Watney; John Doveton; Willard Guy; Rodney Reynolds; Dave Murfin; James Daniels; Russell Martin; William Flanders; Dave Vander Griend; Eric Mork; Paul Cantrell

    2004-06-30

    A pilot carbon dioxide miscible flood was initiated in the Lansing Kansas City C formation in the Hall Gurney Field, Russell County, Kansas. Continuous carbon dioxide injection began on December 2, 2003. By the end of June 2004, 6.26 MM lb of carbon dioxide were injected into the pilot area. Carbon dioxide injection rates averaged about 250 MCFD. Carbon dioxide was detected in one production well near the end of May. The amount of carbon dioxide produced was small during this period. Wells in the pilot area produced 100% water at the beginning of the flood. Oil production began in February, increasing to an average of about 2.5 B/D in May and June. Operational problems encountered during the initial stages of the flood were identified and resolved.

  1. Assessment of a vertical hydrocarbon miscible flood in the Westpem Nisku D reef

    SciTech Connect

    Da Sie, W.J. ); Guo, D.S. )

    1990-05-01

    In 1981, a vertical hydrocarbon miscible flood was implemented in the Westpem Nisku D pool, one of 40 isolated carbonate pinnacle reefs in a trend located west of Edmonton, Alta., Canada. A solvent composed of methane and 15% ethane-plus components was injected into the reservoir, which is maintained at a pressure of about 4,800 psig (33 MPa). Positive indications of the location of the solvent/oil interface have been obtained from interface logging (pulsed-neutron-capture (PNC) logs) in a producing wellbore and from special analysis of core from an infill well recently drilled into the pool. Two types of chromatographic analysis of residual oil and a conventional core residual oil determination were done. The results show that the flood is gravity stable and has excellent volumetric conformance. The special core analysis provided information on the quantity and composition of residual oil saturation (ROS) in the miscibly swept zone. On the basis of these flood performance data, an estimate of ultimate recovery has been prepared.

  2. Development of a method for evaluating carbon dioxide miscible flooding prospects. Final report

    SciTech Connect

    Green, D.W.; Swift, G.W.

    1985-03-01

    Research was undertaken to develop a method of evaluating reservoirs as prospects for carbon dioxide flooding. Evaluation was to be based on a determination of miscibility pressure and displacement efficiency under idealized conditions. To reach the objective, project work was divided into five areas: (1) conducting of phase-equilibrium studies of carbon dioxide with synthetic oils; (2) application of an equation of state to simulate the phase behavior of carbon dioxide - oil systems; (3) conducting of linear displacements of crude oils and synthetic oils by carbon dioxide in a slim-tube apparatus; (4) application of the equation of state, the phase-behavior data and slim-tube data to develop a method of screening reservoirs for carbon dioxide flooding based on determination of minimum miscibility pressure and displacement efficiency; (5) development of a one-dimensional mathematical model, based on the equation of state, for application in conjunction with the results of Parts 1 to 4. The accomplishments for these five areas are discussed in five chapters. 44 references, 90 figures, 42 tables.

  3. FIELD DEMONSTRATION OF CARBON DIOXIDE MISCIBLE FLOODING IN THE LANSING-KANSAS CITY FORMATION, CENTRAL KANSAS

    SciTech Connect

    Alan Byrnes; G. Paul Willhite

    2003-09-30

    Progress is reported for the period from July 1, 2003 to September 30, 2003. Conductivity testing between the CO{sub 2}I No.1 and CO{sub 2} No.13 was performed over the period 08/20/03 through 09/05/03. Observed response in CO{sub 2} 13 production rates to changes in CO{sub 2}I No.1 injection rates are consistent with sufficient permeability between CO{sub 2}I No.1 and CO{sub 2} No.13 for a viable CO{sub 2} flood with a sufficient Process Pore Volume Rate (PPV). Based on the permeabilities near the CO{sub 2} No.16, a 2-producing well pattern has been determined to be optimal but may be changed during the flood depending on the response observed in the CO{sub 2} No.16. Present inter-well test results indicate there is greater permeability architecture complexity than originally predicted and that a low-permeability region or barrier that restricts but does stop flow may exist between the CO{sub 2}I No.1 and the CO{sub 2} No.13. Pilot area repressurization began on 09/05/03, immediately after CO{sub 2}I No.1-CO{sub 2} No.13 conductivity testing was complete, by increasing injection in the CO{sub 2}I No.1, CO{sub 2} No.10, and CO{sub 2} No.18. Adequate reservoir pressure in the portion of the pilot area needed to be above minimum miscibility pressure should be reached in November at which time initial CO{sub 2} injection could begin. It is estimated the 2-producing well, 10+-acre (4.05 ha) producing pattern will produce 18,000-21,000 BO (barrels oil; 2,880-3,360 m{sup 3}). Depending primarily on surface facilities costs, operating expenses, and the price of oil, for the predicted range of oil recovery the pilot is estimated to either break-even or be profitable from this point forward. Final arrangements and agreements for CO{sub 2} supply and delivery are being worked on and will be finalized in the next month.

  4. Post Waterflood CO2 Miscible Flood in Light Oil, Fluvial-Dominated Deltaic Reservoir, Class I

    SciTech Connect

    Bou-Mikael, Sami

    2002-02-05

    This report demonstrates the effectiveness of the CO2 miscible process in Fluvial Dominated Deltaic reservoirs. It also evaluated the use of horizontal CO2 injection wells to improve the overall sweep efficiency. A database of FDD reservoirs for the gulf coast region was developed by LSU, using a screening model developed by Texaco Research Center in Houston. The results of the information gained in this project is disseminated throughout the oil industry via a series of SPE papers and industry open forums.

  5. Review of miscible flood performance, Intisar 'D' field, Socialist people's Libyan Arab Jamahiriya

    SciTech Connect

    DesBrisay, C.L.; El Ghussein, B.; Holst, P.H.; Misellati, A.

    1981-01-01

    The Intisar 'D' reservoir is a major oil field in the Sirte Basin of the Socialist People's Libyan Arab Jamahiriya. The field has been developed with bottom-water injection for pressure support and crestal high pressure miscible gas injection for enhanced oil recovery and gas conservation. This paper presents details of the reservoir performance and simulation study. Field performance results, have been history matched with a three-dimensional, 1,615-grid, two-component black oil simulator. The simulator prediction runs indicate that the final oil recovery efficiency for this dual displacement process will be approximately 70 percent. This high recovery is attributed to effective miscible displacement and gravity drainage together with efficient bottom-water displacement. 4 refs.

  6. Field Demonstration of Carbon Dioxide Miscible Flooding in the Lansing-Kansas City Formation, Central Kansas

    SciTech Connect

    Alan Byrnes; G. Paul Willhite; Don Green; Richard Pancake; JyunSyung Tsau; W. Lynn Watney; John Doveton; Willard Guy; Rodney Reynolds; Dave Murfin; James Daniels; Russell Martin; William Flanders; Dave Vander Griend; Eric Mork; Paul Cantrell

    2010-03-07

    A pilot carbon dioxide miscible flood was initiated in the Lansing Kansas City C formation in the Hall Gurney Field, Russell County, Kansas. The reservoir zone is an oomoldic carbonate located at a depth of about 2900 feet. The pilot consists of one carbon dioxide injection well and three production wells. Continuous carbon dioxide injection began on December 2, 2003. By the end of June 2005, 16.19 MM lb of carbon dioxide was injected into the pilot area. Injection was converted to water on June 21, 2005 to reduce operating costs to a breakeven level with the expectation that sufficient carbon dioxide was injected to displace the oil bank to the production wells by water injection. By March 7,2010, 8,736 bbl of oil were produced from the pilot. Production from wells to the northwest of the pilot region indicates that oil displaced from carbon dioxide injection was produced from Colliver A7, Colliver A3, Colliver A14 and Graham A4 located on adjacent leases. About 19,166 bbl of incremental oil were estimated to have been produced from these wells as of March 7, 2010. There is evidence of a directional permeability trend toward the NW through the pilot region. The majority of the injected carbon dioxide remains in the pilot region, which has been maintained at a pressure at or above the minimum miscibility pressure. Estimated oil recovery attributed to the CO2 flood is 27,902 bbl which is equivalent to a gross CO2 utilization of 4.8 MCF/bbl. The pilot project is not economic.

  7. A simulation research on evaluation of development in shale oil reservoirs by near-miscible CO2 flooding

    NASA Astrophysics Data System (ADS)

    Lai, Fengpeng; Li, Zhiping; Fu, Yingkun; Yang, Zhihao; Li, Hong

    2015-08-01

    Shale oil is a key resource that could mitigate the impending energy shortage in the future. Despite its abundance in China, studies on shale oil are still at the preliminary stage. Shale oil development through CO2 flooding has been successfully implemented in the United States. Therefore, the mechanics of CO2 flooding in shale oil reservoirs should be investigated. This study applies a simulation method to evaluate the development efficiency of CO2 flooding in shale oil reservoirs. Near-miscible CO2 flooding can effectively develop shale oil. After 20 years, recovery could improve by up to 9.56% as a result of depletion development under near-miscible CO2 flooding with 0.5% pore volume gas injection. Horizontal well injection is better than vertical well injection in terms of sweep efficiency and recovery. Cyclic gas injection is superior to continuous gas injection because the former reduces gas channelling. Thus, the use of horizontal wells with near-miscible cyclic gas injections has the potential to effectively develop shale oil reservoirs.

  8. FIELD DEMONSTRATION OF CARBON DIOXIDE MISCIBLE FLOODING IN THE LANSING-KANSAS CITY FORMATION, CENTRAL KANSAS

    SciTech Connect

    Alan Byrnes; G. Paul Willhite; Don Green; Martin Dubois; Richard Pancake; Timothy Carr; W. Lynn Watney; John Doveton; Willard Guy; Rodney Reynolds; Dave Murfn; James Daniels; Russell Martin; William Flanders; Dave Vander Griend; Eric Mork; Paul Cantrell

    2004-12-31

    A pilot carbon dioxide miscible flood was initiated in the Lansing Kansas City C formation in the Hall Gurney Field, Russell County, Kansas. Continuous carbon dioxide injection began on December 2, 2003. By the end of December 2004, 11.39 MM lb of carbon dioxide were injected into the pilot area. Carbon dioxide injection rates averaged about 242 MCFD. Vent losses were excessive during June as ambient temperatures increased. Installation of smaller plungers in the carbon dioxide injection pump reduced the recycle and vent loss substantially. Carbon dioxide was detected in one production well near the end of May and in the second production well in August. No channeling of carbon dioxide was observed. The GOR has remained within the range of 3000-4000 for most the last six months. Wells in the pilot area produced 100% water at the beginning of the flood. Oil production began in February, increasing to an average of about 2.35 B/D for the six month period between July 1 and December 31. Cumulative oil production was 814 bbls. Neither well has experienced increased oil production rates expected from the arrival of the oil bank generated by carbon dioxide injection.

  9. FIELD DEMONSTRATION OF CARBON DIOXIDE MISCIBLE FLOODING IN THE LANSING-KANSAS CITY FORMATION, CENTRAL KANSAS

    SciTech Connect

    Alan Byrnes; G. Paul Willhite; Don Green; Martin Dubois; Richard Pancake; Timothy Carr; W. Lynn Watney; John Doveton; Willard Guy; Rodney Reynolds; Dave Murfin; James Daniels; Russell Martin; William Flanders; Dave Vander Griend; Eric Mork; Paul Cantrell

    2005-12-31

    A pilot carbon dioxide miscible flood was initiated in the Lansing Kansas City C formation in the Hall Gurney Field, Russell County, Kansas. The reservoir zone is an oomoldic carbonate located at a depth of about 2900 feet. The pilot consists of one carbon dioxide injection well and two production wells on about 10 acre spacing. Continuous carbon dioxide injection began on December 2, 2003. By the end of June 2005, 16.19 MM lb of carbon dioxide were injected into the pilot area. Injection was converted to water on June 21, 2005 to reduce operating costs to a breakeven level with the expectation that sufficient carbon dioxide has been injected to displace the oil bank to the production wells by water injection. Wells in the pilot area produced 100% water at the beginning of the flood. Oil production began in February 2004, increasing to an average of about 3.78 B/D for the six month period between January 1 and June 30, 2005 before declining. By the end of December 2005, 14,115 bbls of water were injected into CO2I-1 and 2,091 bbl of oil were produced from the pilot. Injection rates into CO2I-1 declined with time, dropping to an unacceptable level for the project. The injection pressure was increased to reach a stable water injection rate of 100 B/D. However, the injection rate continued to decline with time, suggesting that water was being injected into a region with limited leakoff and production. Oil production rates remained in the range of 3-3.5 B/D following conversion to water injection. There is no evidence that the oil bank generated by injection of carbon dioxide has reached either production well. Continued injection of water is planned to displace oil mobilized by carbon dioxide to the production wells and to maintain the pressure in the PPV region at a level that supports continued miscible displacement as the carbon dioxide is displaced by the injected water.

  10. Field Demonstration of Carbon Dioxide Miscible Flooding in the Lansing-Kansas City Formation, Central Kansas

    SciTech Connect

    Alan Byrnes; G. Paul Willhite; Don Green; Martin Dubois; Richard Pancake; Timothy Carr; W. Lynn Watney; John Doveton; Willard Guy; Rodney Reynolds; Dave Murfin; James Daniels; Russell Martin; William Flanders; Dave Vander Griend; Eric Mork; Paul Cantrell

    2007-03-07

    A pilot carbon dioxide miscible flood was initiated in the Lansing Kansas City C formation in the Hall Gurney Field, Russell County, Kansas. The reservoir zone is an oomoldic carbonate located at a depth of about 2900 feet. The pilot consists of one carbon dioxide injection well and three production wells. Continuous carbon dioxide injection began on December 2, 2003. By the end of June 2005, 16.19 MM lb of carbon dioxide were injected into the pilot area. Injection was converted to water on June 21, 2005 to reduce operating costs to a breakeven level with the expectation that sufficient carbon dioxide has been injected to displace the oil bank to the production wells by water injection. By December 31, 2006, 79,072 bbls of water were injected into CO2 I-1 and 3,923 bbl of oil were produced from the pilot. Water injection rates into CO2 I-1, CO2 No.10 and CO2 No.18 were stabilized during this period. Oil production rates increased from 4.7 B/D to 5.5 to 6 B/D confirming the arrival of an oil bank at CO2 No.12. Production from wells to the northwest of the pilot region indicates that oil displaced from carbon dioxide injection was produced from Colliver No.7, Colliver No.3 and possibly Graham A4 located on an adjacent property. There is evidence of a directional permeability trend toward the NW through the pilot region. The majority of the injected carbon dioxide remains in the pilot region, which has been maintained at a pressure at or above the minimum miscibility pressure. Our management plan is to continue water injection maintaining oil displacement by displacing the carbon dioxide remaining in the C zone,. If the decline rate of production from the Colliver Lease remains as estimated and the oil rate from the pilot region remains constant, we estimate that the oil production attributed to carbon dioxide injection will be about 12,000 bbl by December 31, 2007. Oil recovery would be equivalent to 12 MCF/bbl, which is consistent with field experience in

  11. FIELD DEMONSTRATION OF CARBON DIOXIDE MISCIBLE FLOODING IN THE LANSING-KANSAS CITY FORMATION, CENTRAL KANSAS

    SciTech Connect

    Alan Byrnes; G. Paul Willhite; Don Green; Martin Dubois; Richard Pancake; Timothy Carr; W. Lynn Watney; John Doveton; Willard Guy; Rodney Reynolds; Dave Murfin; James Daniels; Russell Martin; William Flanders; Dave Vander Griend; Eric Mork; Paul Cantrell

    2006-06-30

    A pilot carbon dioxide miscible flood was initiated in the Lansing Kansas City C formation in the Hall Gurney Field, Russell County, Kansas. The reservoir zone is an oomoldic carbonate located at a depth of about 2900 feet. The pilot consists of one carbon dioxide injection well and two production wells on about 10 acre spacing. Continuous carbon dioxide injection began on December 2, 2003. By the end of June 2005, 16.19 MM lb of carbon dioxide were injected into the pilot area. Injection was converted to water on June 21, 2005 to reduce operating costs to a breakeven level with the expectation that sufficient carbon dioxide has been injected to displace the oil bank to the production wells by water injection. Wells in the pilot area produced 100% water at the beginning of the flood. Oil production began in February 2004, increasing to an average of about 3.78 B/D for the six month period between January 1 and June 30, 2005 before declining. By June 30, 2006, 41,566 bbls of water were injected into CO2I-1 and 2,726 bbl of oil were produced from the pilot. Injection rates into CO2I-1 declined with time, dropping to an unacceptable level for the project. The injection pressure was increased to reach a stable water injection rate of 100 B/D. However, the injection rate continued to decline with time, suggesting that water was being injected into a region with limited leakoff and production. Oil production rates remained in the range of 3-3.5 B/D following conversion to water injection. Oil rates increased from about 3.3 B/D for the period from January through March to about 4.7 B/D for the period from April through June. If the oil rate is sustained, this may be the first indication of the arrival of the oil bank mobilized by carbon dioxide injection. A sustained fluid withdrawal rate of about 200 B/D from CO2 No.12 and CO2 No.13 appears to be necessary to obtain higher oil rates. There is no evidence that the oil bank generated by injection of carbon dioxide has

  12. Improved efficiency of miscible CO{sub 2} floods and enhanced prospects for CO{sub 2} flooding heterogeneous reservoirs. Annual report, April 18, 1995--April 17, 1996

    SciTech Connect

    Grigg, R.B.; Schechter, D.S.

    1996-10-01

    The overall goal of this project is to improve the efficiency of miscible CO{sub 2} floods and enhance the prospects for flooding heterogeneous reservoirs. This objective is being accomplished by extending experimental and modeling research in three task areas: (1) foams for selective mobility control in heterogeneous reservoirs, (2) reduction of the amount of CO{sub 2} required in CO{sub 2} floods, and (3) low IFT processes and the possibility of CO{sub 2} flooding in fractured reservoirs. This report provides results of the second year of the three-year project for each of the three task areas. In the first task, we are investigating a desirable characteristic of CO{sub 2}-foam called Selective Mobility Reduction (SMR) that results in an improvement in displacement efficiency by reducing the effects of reservoir heterogeneity. Research on SMR of foam during the past year has focused on three subjects: (1) to verify SMR in different rock permeabilities that are in capillary contact; (2) to test additional surfactants for the SMR property; and (3) to develop a modeling approach to assess the oil recovery efficiency of SMR in CO{sub 2}-foam on a reservoir scale. The experimental results from the composite cores suggest that the rock heterogeneity has significant effect on two phase (CO{sub 2}/brine) flow behavior in porous media, and that foam can favorably control CO{sub 2} mobility. The numerical modeling results suggest that foam with SMR can substantially increase the sweep efficiency and therefore improve oil recovery.

  13. Post waterflood CO{sub 2} miscible flood in light oil, fluvial-dominated deltaic reservoir. FY 1993 annual report

    SciTech Connect

    Davis, D.W.

    1995-03-01

    The project is a Class 1 DOE-sponsored field demonstration project of a CO{sub 2} miscible flood project at the Port Neches Field in Orange County, Texas. The project will determine the recovery efficiency of CO{sub 2} flooding a waterflooded and a partial waterdrive sandstone reservoir at a depth of 5,800. The project will also evaluate the use of a horizontal CO{sub 2} injection well placed at the original oil-water contact of the waterflooded reservoir. A PC-based reservoir screening model will be developed by Texaco`s research lab in Houston and Louisiana State University will assist in the development of a database of fluvial-dominated deltaic reservoirs where CO{sub 2} flooding may be applicable. This technology will be transferred throughout the oil industry through a series of technical papers and industry open forums.

  14. Improved efficiency of miscible CO2 floods and enhanced prospects for CO2 flooding heterogeneous reservoirs. Final report, April 17, 1991--May 31, 1997

    SciTech Connect

    Grigg, R.B.; Schechter, D.S.

    1998-02-01

    From 1986 to 1996, oil recovery in the US by gas injection increased almost threefold, to 300,000 bbl/day. Carbon dioxide (CO{sub 2}) injection projects make up three-quarters of the 191,139 bbl/day production increase. This document reports experimental and modeling research in three areas that is increasing the number of reservoirs in which CO{sub 2} can profitably enhance oil recovery: (1) foams for selective mobility reduction (SMR) in heterogeneous reservoirs, (2) reduction of the amount of CO{sub 2} required in CO{sub 2} floods, and (3) low interfacial tension (97) processes and the possibility of CO{sub 2} flooding in naturally fractured reservoirs. CO{sub 2} injection under miscible conditions can effectively displace oil, but due to differences in density and viscosity the mobility of CO{sub 2} is higher than either oil or water. High CO{sub 2} mobility causes injection gas to finger through a reservoir, causing such problems as early gas breakthrough, high gas production rates, excessive injection gas recycling, and bypassing of much of the reservoir oil. These adverse effects are exacerbated by increased reservoir heterogeneity, reaching an extreme in naturally fractured reservoirs. Thus, many highly heterogeneous reservoirs have not been considered for CO{sub 2} injection or have had disappointing recoveries. One example is the heterogeneous Spraberry trend in west Texas, where only 10% of its ten billion barrels of original oil in place (OOIP) are recoverable by conventional methods. CO{sub 2} mobility can be reduced by injecting water (brine) alternated with CO{sub 2} (WAG) and then further reduced by adding foaming agents-surfactants. In Task 1, we studied a unique foam property, selective mobility reduction (SMR), that effectively reduces the effects of reservoir heterogeneity. Selective mobility reduction creates a more uniform displacement by decreasing CO{sub 2} mobility in higher permeability zones more than in lower permeability zones.

  15. Improved efficiency of miscible CO{sub 2} floods and enhanced prospects for CO{sub 2} flooding heterogeneous reservoirs. Annual report, June 1, 1997--May 31, 1998

    SciTech Connect

    Grigg, R.B.; Schechter, D.S.

    1998-07-01

    The goal of this project is to improve the efficiency of miscible CO{sub 2} floods and enhance the prospects for flooding heterogeneous reservoirs. This report provides results of the first year of the three-year project that will be exploring three principle areas: (1) Fluid and matrix interactions (understanding the problems): interfacial tension (IFT), phase behavior, miscibility, capillary number, injectivity, wettability, and gravity drainage; (2) Conformance control/sweep efficiency (solving the problems): reduction of mobility using foam, diversion by selective mobility reduction (SMR) using foam, improved injectivity, alternating water and gas injection, and using horizontal wells; and (3) Reservoir simulation for improved oil recovery (predicting results): gravity drainage, SMR, CO{sub 2}-foam flooding, interfacial tension, injectivity profile, horizontal wells, and naturally fractured reservoirs. Studies of surfactant foam quality were performed during this first year. Simulation studies on a foam pilot area resulted in an acceptable history match model. The results confirm that the communication path between the foam injection well and a production well had a strong impact on the production performance. A laboratory study to aid in the development of a gravity drainage reservoir was undertaken on the Wellman Unit. Experiments were begun meant to duplicate situations of injectivity loss in WAG flooding and identify factors affecting the injectivity loss. The preliminary results indicate that for a given rock the injectivity loss depends on oil saturation in the core during WAG flooding. The injectivity loss is higher in cores with high in-situ oil saturations during WAG flooding. This effect is being verified by more experimental data.

  16. FIELD DEMONSTRATION OF CARBON DIOXIDE MISCIBLE FLOODING IN THE LANSING-KANSAS CITY FORMATION, CENTRAL KANSAS

    SciTech Connect

    Alan Byrnes; G. Paul Willhite; Don Green; Martin Dubois; Richard Pancake; Timothy Carr; W. Lynn Watney; John Doveton; Willard Guy; Rodney Reynolds; Rajesh Kunjithaya; Dave Murfin; James Daniels; Niall Avison; Russell Martin; William Flanders; Dave Vander Griend; Eric Mork; Paul Cantrell

    2002-03-31

    Progress is reported for the period from January 1, 2002 to March 31, 2002. Technical design and budget for a larger (60-acre, 24.3 ha) CO2 demonstration project are being reviewed by the US DOE for approval. While this review process is being conducted, work is proceeding on well testing to obtain reservoir properties and on the VIP reservoir simulation model to improve model prediction and better understand the controls that certain parameters exert on predicted performance. In addition, evaluation of the economics of commercial application in the surrounding area was performed. In a meeting on January 14, 2002 the possibility of staging the demonstration, starting with a 10-acre sub-pattern flood was raised and the decision made to investigate this plan in detail. The influence of carbon dioxide on oil properties and the influence of binary interaction parameters (BIP) used in the VIP simulator were investigated. VIP calculated swelling factors are in good agreement with published values up to 65% mole-fraction CO2. Swelling factor and saturated liquid density are relatively independent of the BIP over the range of BIPs used (0.08-0.15) up to 65% mole-fraction CO2. Assuming a CO2 EOR recovery rate projected as being most likely by current modeling, commercial scale CO2 flooding at $20/BO is possible in the leases in Hall-Gurney field. Relatively small floods (240-320 acres, 4-6 patterns) are economically viable at $20/BO in areas of very high primary and secondary productivity (>14 MBO/net acre recovery). Leases with moderately high primary and secondary productivity (> 10 MBO/net acre recovery) can be economic when combined with high productivity leases to form larger floods (>640 acres, 9 or more patterns).

  17. Post Waterflood CO2 Miscible Flood in Light Oil, Fluvial-Dominated Deltaic Reservoir (Pre-Work and Project Proposal - Appendix)

    SciTech Connect

    Bou-Mikael, Sami

    2002-02-05

    The main objective of the Port Neches Project was to determine the feasibility and producibility of CO2 miscible flooding techniques enhanced with horizontal drilling applied to a Fluvial Dominated Deltaic reservoir. The second was to disseminate the knowledge gained through established Technology Transfer mechanisms to support DOE's programmatic objectives of increasing domestic oil production and reducing abandonment of oil fields.

  18. Post Waterflood CO2 Miscible Flood in Light Oil, Fluvial-Dominated Deltaic Reservoir (Pre-Work and Project Proposal), Class I

    SciTech Connect

    Bou-Mikael, Sami

    2002-02-05

    This project outlines a proposal to improve the recovery of light oil from waterflooded fluvial dominated deltaic (FDD) reservoir through a miscible carbon dioxide (CO2) flood. The site is the Port Neches Field in Orange County, Texas. The field is well explored and well exploited. The project area is 270 acres within the Port Neches Field.

  19. FIELD DEMONSTRATION OF CARBON DIOXIDE MISCIBLE FLOODING IN THE LANSING-KANSAS CITY FORMATION, CENTRAL KANSAS

    SciTech Connect

    Alan Byrnes; G. Paul Willhite; Don Green; Martin Dubois; Richard Pancake; Timothy Carr; W. Lynn Watney; John Doveton; Willard Guy; Rodney Reynolds; Rajesh Kunjithaya; Dave Murfin; James Daniels; Niall Avison; Russell Martin; William Flanders; Dave Vander Griend; Eric Mork; Paul Cantrell

    2002-06-30

    Progress is reported for the period from July 1, 2002 to September 30, 2002. Assessment of the demonstration site has defined many aspects of the reservoir. Technical design and budget for a larger (60-acre, 24.3 ha) CO2 demonstration project are being reviewed by the US DOE for approval. Further analysis of the pilot site by the partners has indicated that a staged demonstration is considered optimal. A phased approach to implementation of the demonstration is proposed to reduce the risk of uncertainties as to whether the reservoir has basic properties (connectivity and ability to pressure-up) conducive to a meaningful CO2 flood demonstration. The proposed plan is to flood a 10+-acre pattern. The results of this small flood will be used to evaluate the viability of performing a larger-scale ({approx}60-acre) demonstration and will be used by the partners to decide their role in a larger-scale demonstration. The 10+-acre pattern requires the least up-front expense to all parties to obtain the data required to accurately assess the viability and economics of CO2 flooding in the L-KC and of a larger-scale demonstration. In general, the following significant modifications to the original Statement of Work are proposed: (1) The proposed plan would extend the period of Budget Period 1 to May 7, 2003. (2) Redefine the period of Budget Period 2 from 3/7/01-3/7/05 to 5/7/03-3/7/08. (3) Redefine the period of Budget Period 3 from 3/7/05-3/7/06 to 3/7/08-3/7/09. (4) To allow initial verification of the viability of the process before proceeding into the flood demonstration, move activities involved with preparing wells in the flood pattern (Task 5.1), repressurizing the pattern (Task 5.2), and constructing surface facilities (Task 5.3) from Budget Period 2 to Budget Period 1. (5) Allow US Energy Partners (USEP) to be a supplier of carbon dioxide from the ethanol plant in Russell, Kansas. (6) Change the pilot flood pattern, including the number and location of wells involved

  20. Hot-solvent miscible displacement

    SciTech Connect

    Awang, M.; Farouq Ali, S.M.

    1980-01-01

    This work describes an experimental and theoretical investigation of miscible displacement under nonisothermal conditions. The hot miscible floods were performed in an adiabatic glass bead pack, displacing one hydrocarbon by a more viscous hydrocarbon, the latter being at an elevated temperature. As a result, dispersion of both mass and heat took place, and was determined by temperature and concentration measurements. The system was simulated by coupled convective-diffusion and thermal conduction-convection equations. The results of the numerical as well as an approximate analytical solution were compared with the experimentally observed behavior. The numerical and experimental results point to the factors which should be considered in the choice of a solvent for a thermal-miscible type oil recovery process.

  1. FIELD DEMONSTRATION OF CARBON DIOXIDE MISCIBLE FLOODING IN THE LANSING-KANSAS CITY FORMATION, CENTRAL KANSAS

    SciTech Connect

    Alan Byrnes; G. Paul Willhite; Don Green; Martin Dubois; Richard Pancake; Timothy Carr; W. Lynn Watney; John Doveton; Willard Guy; Rodney Reynolds; Rajesh Kunjithaya; Dave Murfin; James Daniels; Niall Avison; Russell Martin; William Flanders; Dave Vander Griend; Eric Mork; Paul Cantrell

    2001-12-31

    Progress is reported for the period from October 1, 2001 to December 31, 2001. Technical design and budget for a larger (60-acre) CO{sub 2} demonstration project are being reviewed by the US DOE for approval. While this review process is being conducted, work is proceeding on well testing to obtain reservoir properties and on the VIP reservoir simulation model to improve model prediction and better understand the controls that certain parameters exert on predicted performance. Testing of present Colliver lease injection water on Lansing-Kansas City (L-KC) oomoldic rock indicates that injection brine must be filtered to < {approx}3-5 um and <15 um to prevent plugging of rocks with permeability as low as 1 md (millidarcy; 0.001 um2) and 10 md (0.01 um2), respectively. Pressure build-up testing on the Carter-Colliver No.7 well is interpreted to indicate the L-KC reservoir surrounding this well is {approx}9 ft (2.7 m) thick having an average effective water permeability of 25-35 md (0.025-0.035 um2) that is connected to the wellbore by either a high permeability fracture, bed, or region with low skin. Reservoir simulation evaluation of gridcell size effect on model oil recovery prediction indicates that, based on the model prediction of distribution of produced oil and CO{sub 2} volumes, oil recovery is strongly influenced by gravity segregation of CO{sub 2} into the upper higher permeability layers and indicates the strong control that vertical permeability and permeability barriers between depositional flood cycles exert on the CO{sub 2} flooding process. Simulations were performed on modifications of the 60-acre, two-injector pattern to evaluate oil recovery using other large-scale patterns. Simulations indicated that several 73-acre patterns with a single injector located near the Colliver No.7 could provide improved economics without increasing the amount of CO{sub 2} injected. The US Energy Partners ethanol plant in Russell, KS began operations in October ahead

  2. Improved Efficiency of Miscible CO{sub 2} Floods and Enhanced Prospects for CO{sub 2} Flooding Heterogeneous Reservoirs

    SciTech Connect

    Boyun Guo; David S. Schechter; Jyun-Syung Tsau; Reid B. Grigg; Shih-Hsien Chang

    1997-10-31

    This work will examine three major areas in which CO{sub 2} flooding can be improved: fluid and matrix interactions, conformance control/sweep efficiency, and reservoir simulation for improved oil recovery. The first full quarter of this project has been completed. We began examining synergistic affects of mixed surfactant versus single surfactant systems to enhance the properties of foams used for improving oil recovery in CO{sub 2} floods. The purpose is to reduce the concentration of surfactants or finding less expensive surfactants. Also, we are examining the effect of oil saturation on the development of foam in CO{sub 2}-surfactant solution systems. CO{sub 2} flooding of low permeability, vugular, and fracture reservoirs are another major thrust of this project. Work conducted this quarter involved simulating gravity stable floods using large core samples; results showed excellent recovery in a low permeability vugular core.

  3. IMPROVED MISCIBLE NITROGEN FLOOD PERFORMANCE UTILIZING ADVANCED RESERVOIR CHARACTERIZATION AND HORIZONTAL LATERALS IN A CLASS I RESERVOIR - EAST BINGER (MARCHAND) UNIT

    SciTech Connect

    Joe Sinner

    2002-03-26

    The objective of this project is two-fold. It will demonstrate use of nitrogen as a widely available, cost-effective and environmentally superior injectant for miscible floods. It will also demonstrate the effectiveness of horizontal wellbores in reducing gas breakthrough and cycling. It is expected that the demonstration will lead to implementation of nitrogen injection projects in areas without readily available carbon dioxide sources. Technology transfer will occur throughout the project.

  4. Improved efficiency of miscible CO{sub 2} floods and enhanced prospects for CO{sub 2} flooding heterogeneous reservoirs

    SciTech Connect

    Grigg, Reid B.; Schechter, David S.; Chang, Shih-Hsien; Tsau, Jyun-Syung; Svec, Robert K.

    2000-02-04

    This project examines three major areas in which CO{sub 2} flooding can be improved: fluid and matrix interactions, conformance control, sweep efficiency, and reservoir simulation for improved oil recovery. This report discusses the activity during the calendar quarter covering October 1, 1999 through December 31, 1999 that covers mostly the second fiscal quarter of the project's third year. Injectivity experiments were performed on two Indian limestone cores. In tests on the first core, a variety of brine, CO{sub 2} WAG, and oil contaminant injection schemes indicated infectivity reduction due to phase conditions and contamination. The results are only quantitative because of plugging and erosion in the core. To date, tests on the second core have investigated the effects of long-term brine stability on the reduction of fluid-rock interaction, in order to quantify fluid effects on infectivity. The authors continue to develop a new approach in reservoir simulation to improve the history matching process on clusters of PCs. The main objective was to improve simulation of complex improved oil recovery methods, such as CO{sub 2}-foam for mobility control and sweep enhancements. Adsorption experiments using circulation and flow-through methods were used to determine the loss of surfactants for economic evaluation. A sacrificial agent, lignosulfonate, was used to reduce the adsorption of the primary foaming agent in both Berea sandstone and Indian limestone. The lignosulfonate has also shown a chromatograph effect, advancing more rapidly through the reservoir, thus initially adsorbing onto the rock before the primary foaming agent arrives. Therefore, considering the simplicity of operation and economics of reducing the cost of expensive surfactant to improve oil recovery, coinjection of lignosulfonate with the primary foaming agent might be a practical approach to consider for field application.

  5. FIELD DEMONSTRATION OF CARBON DIOXIDE MISCIBLE FLOODING IN THE LANSING-KANSAS CITY FORMATION, CENTRAL KANSAS

    SciTech Connect

    Alan Byrnes; G. Paul Willhite; Don Green; Martin Dubois; Richard Pancake; Timothy Carr; W. Lynn Watney; John Doveton; Willard Guy; Rodney Reynolds; Rajesh Kunjithaya; Dave Murfin; James Daniels; Niall Avison; Russell Martin; William Flanders; Dave Vander Griend; Eric Mork; Paul Cantrell

    2002-09-30

    Progress is reported for the period from July 1, 2002 to September 30, 2002. On September 27, 2002 the US DOE approved the proposed modified plan to flood a 10+-acre pattern. MV Energy has received informal notification that GE Capital will approve sale of the portion of the Colliver lease involved in the pilot. Murfin Drilling Company is seeking local small independent partners for the pilot and has received commitment from White Eagle Energy and John O. Farmer Oil Company to date. A Contract was signed between the Kansas Department of Commerce & Housing and Murfin formalizing the KSDOC&H contribution of $88,000 to the pilot project. This money will be used for well rework and testing. The results of this small flood will be used to evaluate the viability of performing a larger-scale demonstration and will be used by the partners to decide their role in a larger-scale demonstration. The 10+-acre pattern requires the least up-front expense to all parties to obtain the data required to accurately assess the viability and economics of CO2 flooding in the L-KC and of a larger-scale demonstration. Proposed modifications to the project plan were reviewed in the previous quarterly technical progress report.

  6. FIELD DEMONSTRATION OF CARBON DIOXIDE MISCIBLE FLOODING IN THE LANSING-KANSAS CITY FORMATION, CENTRAL KANSAS

    SciTech Connect

    Alan Byrnes; G. Paul Willhite; Don Green; Martin Dubois; Richard Pancake; Timothy Carr; W. Lynn Watney; John Doveton; Willard Guy; Rodney Reynolds; Rajesh Kunjithaya; Dave Murfin; James Daniels; Niall Avison; Russell Martin; William Flanders; Dave Vander Griend; Eric Mork; Paul Cantrell

    2003-06-30

    Progress is reported for the period from April 1, 2003 to June 30, 2003. The pilot water injection plant became operational 4/18/03 and began long-term injection in the CO2I No.1 on 4/23/03. The CO2I No.1 exhibits sufficient injectivity for pilot requirements with average absolute permeability surrounding this well equal to {approx}85 millidarcies. Response to injection in the CO2I No.1 has established that conductivity between CO2I No.1 and CO2 No.12, No.10, No.18 and TB Carter No.5 is sufficient for the demonstration. Workovers of the CO2 No.16 and CO2 No.13 were completed in April and May, respectively. Pressure response indicates No.16 communicates with the flood pattern area but core, swab-test, and pressure response data indicate permeability surrounding No.16 is not adequate to maintain the production rates needed to support the original pattern as the well is presently completed. Decisions concerning possible further testing and stimulation have been postponed until after testing of the No.13 is complete. Production rates for the No.13 are consistent with a surrounding reservoir average absolute permeability of {approx}80 md. However, pressure and rate tests results, partially due to the nature of the testing conducted to date, have not confirmed the nature of the CO2I No.1-CO2 No.13 conductivity. A build-up test and conductivity test are planned to begin the first weeks of the next quarter to obtain reservoir properties data and establish the connectivity and conductivity between CO2 I-1 and CO2 No.13. A new geomodel of the pattern area has been developed based on core from No.16 and the new wireline logs from the No.10, No.12, No.16, and No.13. The new geomodel is currently being incorporated into the basic calculations of reservoir volume and flood design and predicted response as well as the reservoir simulators. Murfin signed a letter agreement with FLOCO2 of Odessa, TX for supply of CO2 storage and injection equipment. Technology transfer activities

  7. FIELD DEMONSTRATION OF CARBON DIOXIDE MISCIBLE FLOODING IN THE LANSING-KANSAS CITY FORMATION, CENTRAL KANSAS

    SciTech Connect

    Alan P. Byrnes; G. Paul Willhite

    2003-01-01

    Progress is reported for the period from October 1, 2002 to December 31, 2002. On September 27, 2002 the US DOE approved the proposed modified plan to flood a 10+-acre pattern. On November 1, 2002 Murfin Drilling Company purchased the 70-acre pilot area and will continue as the operator of the pilot. Murfin is seeking working interest partners and meetings with local small independents were conducted. To date, White Eagle Resources and John O. Farmer Oil Company have committed to working interest in the project. Arrangements have been made with Rein Operating to test the Rein No. 7 water supply well on the neighboring lease. Based on review of wellbore conditions in the Colliver No. 9 and No. 16 it has been decided to use the No. 16 in the pilot. A new tank battery was installed near the Colliver No. 10 well and the existing producers plumbed to the new tank battery to isolate production from the pilot area. Reservoir simulations have indicated that the low-permeability interval in the Carter-Colliver CO2I No. 1 injection well below 2,900 ft does not exhibit sufficient injectivity to warrant special stimulation or conformance treatment programs at the present time. Discussions have been initiated with FLOCO2 and preliminary conditions have been agreed upon for the exchange of CO2 for the use of storage and pump equipment at the pilot. A short-term injection test and the well reworks have been scheduled. Proposed modifications to the project plan were reviewed in the previous quarterly technical progress report. A presentation was given at the DOE Class II Review Meeting in Midland, TX on December 12, 2002.

  8. Improved Miscible Nitrogen Flood Performance Utilizing Advanced Reservoir Characterization and Horizontal Laterals in a Class I Reservoir - East Binger (Marchand) Unit

    SciTech Connect

    Joe Sinner

    2004-06-30

    The DOE-sponsored project at the East Binger Unit is an investigation into the benefits of reservoir characterization and horizontal wells in this particular setting of geologic and recovery method. The geologic setting is a tight (average porosity of 7% and average permeability of less than 1 millidarcy) Pennsylvanian-age sandstone at about 10,000 feet, and the recovery method is a miscible nitrogen flood. The projected oil recovery of the East Binger Unit, prior to the initiation of this project, was about 25%. Gravity segregation of nitrogen and crude oil was believed to be the principal cause of the poor sweep efficiency, and it was envisioned that with horizontal producing wells in the lower portion of the reservoir and horizontal injection wells near the top, the process could be converted from a lateral displacement process to a vertical displacement/gravity assisted process. Through the characterization and field development work completed in Budget Periods 1 and 2, Binger Operations, LLC (BOL) has developed a different interpretation of the sweep problem as well as a different approach to improving recovery. The sweep problem is now believed to be one of an areal nature, due to a combination of natural and hydraulic fracturing. Vertical wells have provided a much better economic return than have the horizontal wells. The natural and hydraulic fracturing manifests itself as a direction of higher permeability, and the flood is being converted to a line drive flood aligned with this orientation. Consistent with this concept, horizontal wells have been drilled along the line of the fracture orientation, such that hydraulic fracturing leads to 'longitudinal' fractures, in line with the wellbore. As such, the hydraulically fractured horizontal wells are not significantly different than hydraulically fractured vertical wells - save for the potential for a much longer fracture face. This Topical Report contains data from new wells, plus new and updated production

  9. Broader Understanding of Multiple Component Dynamic Processes in Miscible Polymer/Polymer Blends

    NASA Astrophysics Data System (ADS)

    Sharma, Ravi; Yang, Hengxi; Green, Peter

    Utilizing two different experimental techniques, isothermal frequency sweeps and isochronal temperature sweeps, in broadband dielectric spectroscopy can allow for the identification of multiple processes derived from the same relaxation mechanism in certain polymer/polymer blends. A study of poly(vinyl methyl ether) (PVME) in bulk, miscible blends with polystyrene (PS) gives evidence of two separate relaxation processes associated exclusively with the segmental dynamics of PVME; the α0 process from the temperature sweep, related to average segmental dynamics, and the α' process from the frequency sweep, related to relaxations confined within ``frozen'' domains. The appearance of multiple processes is driven by compositional heterogeneity, mainly chain connectivity and concentration fluctuation effects. Analysis of the breadth and intensity of the dielectric loss curves gives insight into the structure and thermodynamics of the blend, which in turn can explain temperature and composition dependent dynamic trends. These results are contrasted with other miscible blend systems, polyisoprene (PI)/poly(4-tert-butylstyrene) (P4tBS) and polyisoprene (PI)/polyvinyl ether (PVE).

  10. 4D seismic to image a thin carbonate reservoir during a miscible C02 flood: Hall-Gurney Field, Kansas, USA

    USGS Publications Warehouse

    Raef, A.E.; Miller, R.D.; Franseen, E.K.; Byrnes, A.P.; Watney, W.L.; Harrison, W.E.

    2005-01-01

    The movement of miscible CO2 injected into a shallow (900 m) thin (3.6-6m) carbonate reservoir was monitored using the high-resolution parallel progressive blanking (PPB) approach. The approach concentrated on repeatability during acquisition and processing, and use of amplitude envelope 4D horizon attributes. Comparison of production data and reservoir simulations to seismic images provided a measure of the effectiveness of time-lapse (TL) to detect weak anomalies associated with changes in fluid concentration. Specifically, the method aided in the analysis of high-resolution data to distinguish subtle seismic characteristics and associated trends related to depositional lithofacies and geometries and structural elements of this carbonate reservoir that impact fluid character and EOR efforts.

  11. Improved Miscible Nitrogen Flood Performance Utilizing Advanced Reservoir Characterization and Horizontal Laterals in a Class I Reservoir - East Binger (Marchand) Unit

    SciTech Connect

    Joe Sinner

    2006-06-30

    The reservoir characterization and investigation of the benefits of horizontal wells in the East Binger Unit miscible nitrogen flood as been completed. A significant work program was implemented from 2002 to 2005 in an effort to reduce gas cycling and economically increase ultimate oil recovery. Horizontal and vertical infill wells were drilled and existing producers were converted to injection. Due to successful infill drilling based on the improved flow characterization, more drilling was done than originally planned, and further drilling will occur after the project is completed. Through the drilling of wells and reservoir characterization work, it was determined that poor areal sweep efficiency is the primary factor causing nitrogen cycling and limiting oil recovery. This is in contrast to the perception prior to the initiation of development, which was that gravity segregation was causing poor vertical sweep efficiency. Although not true of all infill wells, most were drilled in areas with little sweep and came online producing gas with much lower nitrogen contents than previously drilled wells in the field and in the pilot area. Seven vertical and three horizontal wells were drilled in the pilot area throughout the project. As previously reported, the benefits of horizontal drilling were found to be insufficient to justify their increased cost. Nitrogen recycle, defined as nitrogen production as a percentage of injection, decreased from 72% prior to initiation of the project to about 25% before rising back to a current rate of 40%. Injection into the pilot area, despite being limited at times by problems in the Air Separation Unit of the Nitrogen Management Facility, increased 60% over levels prior to the project. Meanwhile, gas production and nitrogen content of produced gas both decreased.

  12. 4D seismic monitoring of the miscible CO2 flood of Hall-Gurney Field, Kansas, U.S

    USGS Publications Warehouse

    Raef, A.E.; Miller, R.D.; Byrnes, A.P.; Harrison, W.E.

    2004-01-01

    A cost-effective, highly repeatable, 4D-optimized, single-pattern/patch seismic data-acquisition approach with several 3D data sets was used to evaluate the feasibility of imaging changes associated with the " water alternated with gas" (WAG) stage. By incorporating noninversion-based seismic-attribute analysis, the time and cost of processing and interpreting the data were reduced. A 24-ms-thick EOR-CO 2 injection interval-using an average instantaneous frequency attribute (AIF) was targeted. Changes in amplitude response related to decrease in velocity from pore-fluid replacement within this time interval were found to be lower relative to background values than in AIF analysis. Carefully color-balanced AIF-attribute maps established the overall area affected by the injected EOR-CO2.

  13. Combustion-process derived comparable performances of Zn-(In:Sn)-O thin-film transistors with a complete miscibility

    SciTech Connect

    Jiang, Qingjun; Lu, Jianguo Cheng, Jipeng; Sun, Rujie; Feng, Lisha; Dai, Wen; Yan, Weichao; Ye, Zhizhen; Li, Xifeng

    2014-09-29

    Amorphous zinc-indium-tin oxide (a-ZITO) thin-film transistors (TFTs) have been prepared using a low-temperature combustion process, with an emphasis on complete miscibility of In and Sn contents. The a-ZITO TFTs were comparatively studied in detail, especially for the working stability. The a-ZITO TFTs all exhibited acceptable and excellent behaviors from Sn-free TFTs to In-free TFTs. The obtained a-ZTO TFTs presented a field-effect mobility of 1.20 cm{sup 2} V{sup −1} s{sup −1}, an on/off current ratio of 4.89 × 10{sup 6}, and a long-term stability under positive bias stress, which are comparable with those of the a-ZIO TFTs. The In-free a-ZTO TFTs are very potential for electrical applications with a low cost.

  14. 44 CFR 78.6 - Flood Mitigation Plan approval process.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 44 Emergency Management and Assistance 1 2014-10-01 2014-10-01 false Flood Mitigation Plan..., DEPARTMENT OF HOMELAND SECURITY INSURANCE AND HAZARD MITIGATION National Flood Insurance Program FLOOD MITIGATION ASSISTANCE § 78.6 Flood Mitigation Plan approval process. The State POC will forward all...

  15. 44 CFR 78.6 - Flood Mitigation Plan approval process.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 44 Emergency Management and Assistance 1 2012-10-01 2011-10-01 true Flood Mitigation Plan approval..., DEPARTMENT OF HOMELAND SECURITY INSURANCE AND HAZARD MITIGATION National Flood Insurance Program FLOOD MITIGATION ASSISTANCE § 78.6 Flood Mitigation Plan approval process. The State POC will forward all...

  16. 44 CFR 78.6 - Flood Mitigation Plan approval process.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 44 Emergency Management and Assistance 1 2013-10-01 2013-10-01 false Flood Mitigation Plan..., DEPARTMENT OF HOMELAND SECURITY INSURANCE AND HAZARD MITIGATION National Flood Insurance Program FLOOD MITIGATION ASSISTANCE § 78.6 Flood Mitigation Plan approval process. The State POC will forward all...

  17. 44 CFR 78.6 - Flood Mitigation Plan approval process.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 44 Emergency Management and Assistance 1 2011-10-01 2011-10-01 false Flood Mitigation Plan..., DEPARTMENT OF HOMELAND SECURITY INSURANCE AND HAZARD MITIGATION National Flood Insurance Program FLOOD MITIGATION ASSISTANCE § 78.6 Flood Mitigation Plan approval process. The State POC will forward all...

  18. 44 CFR 78.6 - Flood Mitigation Plan approval process.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Flood Mitigation Plan..., DEPARTMENT OF HOMELAND SECURITY INSURANCE AND HAZARD MITIGATION National Flood Insurance Program FLOOD MITIGATION ASSISTANCE § 78.6 Flood Mitigation Plan approval process. The State POC will forward all...

  19. Post waterflood CO{sub 2} miscible flood in light oil, fluvial-dominated deltaic reservoir. Annual report, October 1, 1993--September 30, 1994

    SciTech Connect

    Bou-Mikael, S.

    1995-07-01

    Texaco Exploration and Production Inc. (TEPI) and the U.S. Department of Energy (DOE) entered into a cost sharing cooperative agreement to conduct an Enhanced Oil Recovery demonstration project at Port Neches. The field is located in Orange County near Beaumont, Texas. The project will demonstrate the effectiveness of the CO{sub 2}, miscible process in Fluvial Dominated Deltaic reservoirs. It will also evaluate the use of horizontal CO{sub 2} injection wells to improve the overall sweep efficiency. A data base of FDD reservoirs for the gulf coast region will be developed by LSU, using a screening model developed by Texaco Research Center in Houston. Finally, the results and the information gained from this project will be disseminated throughout the oil industry via a series of SPE papers and industry open forums. Reservoir characterization efforts for the Marginulina sand, are in progress utilizing conventional and advanced technologies including 3-D seismic. Sidewall and conventional. cores were cut and analyzed, lab tests were conducted on reservoir fluids, reservoir BHP pressure and reservoir voidage were monitored as shown. Texaco is utilizing the above data to develop a Stratamodel to best describe and characterize the reservoir and to use it as an input for the compositional simulator. The current compositional model is being revised to integrate the new data from the 3-D seismic and field performance under CO{sub 2} injection, to ultimately develop an accurate economic model. All facilities work has been completed and placed in service including the CO{sub 2} pipeline and metering equipment, CO{sub 2} injection and production equipment, water injection equipment, well work and injection/production lines. The horizontal injection well was drilled and completed on January 15, 1994. CO{sub 2} purchases from Cardox continue at an average rate of 3600 MCFD. The CO{sub 2} is being injected at line pressure of 1350 psi.

  20. Flood adaptive traits and processes: an overview.

    PubMed

    Voesenek, Laurentius A C J; Bailey-Serres, Julia

    2015-04-01

    Unanticipated flooding challenges plant growth and fitness in natural and agricultural ecosystems. Here we describe mechanisms of developmental plasticity and metabolic modulation that underpin adaptive traits and acclimation responses to waterlogging of root systems and submergence of aerial tissues. This includes insights into processes that enhance ventilation of submerged organs. At the intersection between metabolism and growth, submergence survival strategies have evolved involving an ethylene-driven and gibberellin-enhanced module that regulates growth of submerged organs. Opposing regulation of this pathway is facilitated by a subgroup of ethylene-response transcription factors (ERFs), which include members that require low O₂ or low nitric oxide (NO) conditions for their stabilization. These transcription factors control genes encoding enzymes required for anaerobic metabolism as well as proteins that fine-tune their function in transcription and turnover. Other mechanisms that control metabolism and growth at seed, seedling and mature stages under flooding conditions are reviewed, as well as findings demonstrating that true endurance of submergence includes an ability to restore growth following the deluge. Finally, we highlight molecular insights obtained from natural variation of domesticated and wild species that occupy different hydrological niches, emphasizing the value of understanding natural flooding survival strategies in efforts to stabilize crop yields in flood-prone environments. PMID:25580769

  1. Glacier lake outburst floods - modelling process chains

    NASA Astrophysics Data System (ADS)

    Schaub, Yvonne; Huggel, Christian; Haeberli, Wilfried

    2013-04-01

    New lakes are forming in high-mountain areas all over the world due to glacier recession. Often they will be located below steep, destabilized flanks and are therefore exposed to impacts from rock-/ice-avalanches. Several events worldwide are known, where an outburst flood has been triggered by such an impact. In regions such as in the European Alps or in the Cordillera Blanca in Peru, where valley bottoms are densely populated, these far-travelling, high-magnitude events can result in major disasters. For appropriate integral risk management it is crucial to gain knowledge on how the processes (rock-/ice-avalanches - impact waves in lake - impact on dam - outburst flood) interact and how the hazard potential related to corresponding process chains can be assessed. Research in natural hazards so far has mainly concentrated on describing, understanding, modeling or assessing single hazardous processes. Some of the above mentioned individual processes are quite well understood in their physical behavior and some of the process interfaces have also been investigated in detail. Multi-hazard assessments of the entire process chain, however, have only recently become subjects of investigations. Our study aims at closing this gap and providing suggestions on how to assess the hazard potential of the entire process chain in order to generate hazard maps and support risk assessments. We analyzed different types of models (empirical, analytical, physically based) for each process regarding their suitability for application in hazard assessments of the entire process chain based on literature. Results show that for rock-/ice-avalanches, dam breach and outburst floods, only numerical, physically based models are able to provide the required information, whereas the impact wave can be estimated by means of physically based or empirical assessments. We demonstrate how the findings could be applied with the help of a case study of a recent glacier lake outburst event at Laguna

  2. An investigation into the influence of drug-polymer interactions on the miscibility, processability and structure of polyvinylpyrrolidone-based hot melt extrusion formulations.

    PubMed

    Chan, Siok-Yee; Qi, Sheng; Craig, Duncan Q M

    2015-12-30

    While hot melt extrusion is now established within the pharmaceutical industry, the prediction of miscibility, processability and structural stability remains a pertinent issue, including the issue of whether molecular interaction is necessary for suitable performance. Here we integrate the use of theoretical and experimental drug-polymer interaction assessment with determination of processability and structure of dispersions in two polyvinylpyrrolidone-based polymers (PVP and PVP vinyl acetate, PVPVA). Caffeine and paracetamol were chosen as model drugs on the basis of their differing hydrogen bonding potential with PVP. Solubility parameter and interaction parameter calculations predicted a greater miscibility for paracetamol, while ATR-FTIR confirmed the hydrogen bonding propensity of the paracetamol with both polymers, with little interaction detected for caffeine. PVP was found to exhibit greater interaction and miscibility with paracetamol than did PVPVA. It was noted that lower processing temperatures (circa 40°C below the Tg of the polymer alone and Tm of the crystalline drug) and higher drug loadings with associated molecular dispersion up to 50% w/w were possible for the paracetamol dispersions, although molecular dispersion with the non-interactive caffeine was noted at loadings up to 20% w./w. A lower processing temperature was also noted for caffeine-loaded systems despite the absence of detectable interactions. The study has therefore indicated that theoretical and experimental detection of miscibility and drug-polymer interactions may lead to insights into product processing and extrudate structure, with direct molecular interaction representing a helpful but not essential aspect of drug-polymer combination prediction. PMID:26428633

  3. Study of hydrocarbon miscible solvent slug injection process for improved recovery of heavy oil from Schrader Bluff Pool, Milne Point Unit, Alaska. Final report

    SciTech Connect

    1995-11-01

    The National Energy Strategy Plan (NES) has called for 900,000 barrels/day production of heavy oil in the mid-1990s to meet our national needs. To achieve this goal, it is important that the Alaskan heavy oil fields be brought to production. Alaska has more than 25 billion barrels of heavy oil deposits. Conoco, and now BP Exploration have been producing from Schrader Bluff Pool, which is part of the super heavy oil field known as West Sak Field. Schrader Bluff reservoir, located in the Milne Point Unit, North Slope of Alaska, is estimated to contain up to 1.5 billion barrels of (14 to 21{degrees}API) oil in place. The field is currently under production by primary depletion; however, the primary recovery will be much smaller than expected. Hence, waterflooding will be implemented earlier than anticipated. The eventual use of enhanced oil recovery (EOR) techniques, such as hydrocarbon miscible solvent slug injection process, is vital for recovery of additional oil from this reservoir. The purpose of this research project was to determine the nature of miscible solvent slug which would be commercially feasible, to evaluate the performance of the hydrocarbon miscible solvent slug process, and to assess the feasibility of this process for improved recovery of heavy oil from Schrader Bluff reservoir. The laboratory experimental work includes: slim tube displacement experiments and coreflood experiments. The components of solvent slug includes only those which are available on the North Slope of Alaska.

  4. Post waterflood CO{sub 2} miscible flood in light oil, fluvial dominated deltaic reservoir. Third quarterly technical progress report, September 15, 1992--June 30, 1993

    SciTech Connect

    Not Available

    1993-07-15

    Texaco`s objective on this project has been to utilize all available technologies, and to develop new ones, to design a CO{sub 2} flood process which is cost effective and can be applied to many other reservoirs throughout the United States. This project will determine the recovery efficiency of CO{sub 2} floods in waterflooded and partial waterdrive reservoirs. A PC-based CO{sub 2} screening model will be developed and a database will be generated to show the utility of this technology throughout the US. After Pre-award costs were approved on September 15, 1992, Texaco proceeded with the implementation phase of the project so that new data could be gathered and necessary steps required to initiate CO{sub 2} injection could be accomplished. An expenditure of $7,080,191 has put Texaco in a position where CO{sub 2} injection can begin by September 1, 1993. The following tasks have been accomplished: (1) 10 workovers (4 injection, 6 producers) are complete. Production has increased from 78 BOPD to 183 BOPD. (2) Reservoir pressure has been increased from 1850 psi-to 2700 psi by injecting saltwater. (3) Compressors, a CO{sub 2} injection pump, and separators have been installed on a floating barge, and is being transported to the field by a tug boat. (4) 3 miles of the 4.5 mile CO{sub 2} pipeline has been installed. (5) A residual oil saturation of 30% to 35% has been measured from a new conventional core. A set of relative permeability curves have been developed.

  5. 3-D hydrodynamic modelling of flood impacts on a building and indoor flooding processes

    NASA Astrophysics Data System (ADS)

    Gems, Bernhard; Mazzorana, Bruno; Hofer, Thomas; Sturm, Michael; Gabl, Roman; Aufleger, Markus

    2016-06-01

    Given the current challenges in flood risk management and vulnerability assessment of buildings exposed to flood hazards, this study presents three-dimensional numerical modelling of torrential floods and its interaction with buildings. By means of a case study application, the FLOW-3D software is applied to the lower reach of the Rio Vallarsa torrent in the village of Laives (Italy). A single-family house on the flood plain is therefore considered in detail. It is exposed to a 300-year flood hydrograph. Different building representation scenarios, including an entire impervious building envelope and the assumption of fully permeable doors, light shafts and windows, are analysed. The modelling results give insight into the flooding process of the building's interior, the impacting hydrodynamic forces on the exterior and interior walls, and further, they quantify the impact of the flooding of a building on the flow field on the surrounding flood plain. The presented study contributes to the development of a comprehensive physics-based vulnerability assessment framework. For pure water floods, this study presents the possibilities and limits of advanced numerical modelling techniques within flood risk management and, thereby, the planning of local structural protection measures.

  6. Process for emulsion flooding of petroleum reservoirs

    SciTech Connect

    Lepper, U.

    1984-12-18

    A process for emulsion flooding of petroleum reservoirs comprising injecting a thermodynamically stable microemulsion consisting of oil, a non-ionic surfactant and water which optionally contains salts dissolved in any desired concentrations, into an injection well; driving injected microemulsion bank through the reservoir by means of water which likewise may contain salts dissolved in any desired concentrations. The microemulsion bank in contact with the water driving the bank forms an excess phase with a high water content, a low surfactant content and low oil content, and has such a viscosity sufficient to prevent the penetration of the subsequent water into the microemulsion bank which would cause a decrease of its flowability and its ability to displace oil.

  7. Multiphase flow of miscible liquids: jets and drops

    NASA Astrophysics Data System (ADS)

    Walker, Travis W.; Logia, Alison N.; Fuller, Gerald G.

    2015-05-01

    Drops and jets of liquids that are miscible with the surrounding bulk liquid are present in many processes from cleaning surfaces with the aid of liquid soaps to the creation of biocompatible implants for drug delivery. Although the interactions of immiscible drops and jets show similarities to miscible systems, the small, transient interfacial tension associated with miscible systems create distinct outcomes such as intricate droplet shapes and breakup resistant jets. Experiments have been conducted to understand several basic multiphase flow problems involving miscible liquids. Using high-speed imaging of the morphological evolution of the flows, we have been able to show that these processes are controlled by interfacial tensions. Further multiphase flows include investigating miscible jets, which allow the creation of fibers from inelastic materials that are otherwise difficult to process due to capillary breakup. This work shows that stabilization from the diminishing interfacial tensions of the miscible jets allows various elongated morphologies to be formed.

  8. Improved Miscible Nitrogen Flood Performance Utilizing Advanced Reservoir Characterization and Horizontal Laterals in a Class I Reservoir--East Binger (Marchand) Unit

    SciTech Connect

    Joe Sinner

    2006-05-18

    A significant work program was implemented from 2002 to 2005 in the East Binger Unit (''EBU'') miscible nitrogen injection project in an effort to reduce gas cycling and economically increase ultimate oil recovery. This work included the drilling of new wells, both horizontal and vertical, as well as pattern realignment through producer-to-injector conversions. Monitoring of overall performance of the pilot area continues. Response to the various projects continues to be very favorable. Injection into the pilot area, despite being limited at times by problems in the Air Separation Unit of the Nitrogen Management Facility, has increased an average of 60% over levels prior to the project. Meanwhile, gas production and nitrogen content of produced gas have both decreased. After decreasing to 20-25% early in the project, nitrogen recycle (produced nitrogen volume divided by injected nitrogen volume) within the pilot area has risen to about 40%, still far below the 72% prior to initiation of the project. Poor areal sweep efficiency appears to be the primary cause of nitrogen cycling. Seven vertical and three horizontal wells have been drilled in the pilot area throughout the project, and most have had initial produced gas oil ratios and gas nitrogen contents significantly below the field averages. Given similar reservoir conditions of net thickness and gas sweep, vertical wells are performing nearly as well as horizontal wells. Additional vertical well drilling was completed in 2005 following the success of wells drilled from 2002 through 2004.

  9. Flood risk under future climate in West Africa: linking extreme value models and flood generating processes

    NASA Astrophysics Data System (ADS)

    Tramblay, Yves; Amoussou, Ernest; Dorigo, Wouter; Mahé, Gil

    2014-05-01

    For many areas in the world, there is a need for future projections of flood risk in order to improve the possible mitigation actions. However, such an exercise is often made difficult in data-sparse regions, where the limited access to hydrometric data does not allow calibrating hydrological models in a robust way under non-stationary conditions. In this study we present an approach to estimate the possible changes in flood risks, which incorporates flood generating processes into statistical models for extreme values. This approach is illustrated for a West African catchment, the Mono River (12900km²), with discharge, precipitation and temperature data are available between 1988 and 2010 in a few stations and where the dominant flood generating process is soil saturation. A soil moisture accounting model, calibrated against a merged surface soil moisture microwave satellite dataset, is used to estimate the annual maximum soil saturation level that is then related to the location parameter of a Generalized Extreme Value model of annual maximum discharge. With such a model, it is possible to estimate the changes in flood quantiles from the changes in the annual maximum soil saturation level. An ensemble of regional climate models from the ENSEMBLES-AMMA project are then considered to estimate the potential future changes in soil saturation and subsequently the changes in flood risks for the period 2028-2050. A sensitivity analysis of the non-stationary flood quantiles has shown that with the projected changes on precipitation (-2%) and temperature (+1.22°) under the scenario A1B, the projected flood quantiles would stay in the range of the observed variability during 1988-2010. The proposed approach, relying on low data requirements and few assumptions, could be useful to estimate the projected changes in flood risks for other data-sparse catchments.

  10. Spreading of miscible liquids

    NASA Astrophysics Data System (ADS)

    Walls, Daniel J.; Haward, Simon J.; Shen, Amy Q.; Fuller, Gerald G.

    2016-05-01

    Miscible liquids commonly contact one another in natural and technological situations, often in the proximity of a solid substrate. In the scenario where a drop of one liquid finds itself on a solid surface and immersed within a second, miscible liquid, it will spread spontaneously across the surface. We show experimental findings of the spreading of sessile drops in miscible environments that have distinctly different shape evolution and power-law dynamics from sessile drops that spread in immiscible environments, which have been reported previously. We develop a characteristic time to scale radial data of the spreading sessile drops based on a drainage flow due to gravity. This time scale is effective for a homologous subset of the liquids studied. However, it has limitations when applied to significantly chemically different, yet miscible, liquid pairings; we postulate that the surface energies between each liquid and the solid surface becomes important for this other subset of the liquids studied. Initial experiments performed with pendant drops in miscible environments support the drainage flow observed in the sessile drop systems.

  11. Reduced biodegradability in a polymer flood process

    SciTech Connect

    Williams, D.; Munnecke, D. M.

    1985-05-14

    In a polymer flood, where bacterial contamination frequently causes a loss in viscosity of the polymer, the viscosity of the polymer solution is maintained by the use of a xanthan polymer modified by methylation of a portion of the subunit sugar residues of the xanthan base.

  12. Comparison of oil removal in surfactant alternating gas with water alternating gas, water flooding and gas flooding in secondary oil recovery process

    PubMed Central

    Salehi, Mehdi Mohammad; Safarzadeh, Mohammad Amin; Sahraei, Eghbal; Nejad, Seyyed Alireza Tabatabaei

    2014-01-01

    Growing oil prices coupled with large amounts of residual oil after operating common enhanced oil recovery methods has made using methods with higher operational cost economically feasible. Nitrogen is one of the gases used in both miscible and immiscible gas injection process in oil reservoir. In heterogeneous formations gas tends to breakthrough early in production wells due to overriding, fingering and channeling. Surfactant alternating gas (SAG) injection is one of the methods commonly used to decrease this problem. Foam which is formed on the contact of nitrogen and surfactant increases viscosity of injected gas. This increases the oil–gas contact and sweep efficiency, although adsorption of surfactant on rock surface can causes difficulties and increases costs of process. Many parameters must be considered in design of SAG process. One of the most important parameters is SAG ratio that should be in optimum value to improve the flooding efficiency. In this study, initially the concentration of surfactant was optimized due to minimization of adsorption on rock surface which results in lower cost of surfactant. So, different sodium dodecyl sulfate (SDS) concentrations of 100, 500, 1000, 2000, 3000 and 4000 ppm were used to obtain the optimum concentration at 70 °C and 144.74×105 Pa. A simple, clean and relatively fast spectrophotometric method was used for determination of surfactant which is based on the formation of an ion-pair. Then the effect of surfactant to gas volume ratio on oil recovery in secondary oil recovery process during execution of immiscible surfactant alternating gas injection was examined experimentally. The experiments were performed with sand pack under certain temperature, pressure and constant rate. Experiments were performed with surfactant to gas ratio of 1:1, 1:2, 1:3, 2:1 and 3:1 and 1.2 pore volume injected. Then, comparisons were made between obtained results (SAG) with water flooding, gas flooding and water alternating gas

  13. Post waterflood CO{sub 2} miscible flood in light oil, fluvial-dominated deltaic reservoir. Annual report, fiscal year 1996

    SciTech Connect

    1996-08-15

    The Port Neches CO{sub 2} flood has been operating for nearly 4 years. The project performance during the past year has been adversely affected by several factors including: water blockage, low residual oil saturation and wellbore mechanical problems. The company attempted to test a new procedure in a new fault block using CO{sub 2} to accelerate primary production in order to improve the primary reserves net present value. The test was abandoned when the discovery well Polk B-39 for the Marg Area 3 was a dry hole. Also, during this period the company terminated all new CO{sub 2} purchases from Cardox for economical reasons, while continuing to recycle produced CO{sub 2}. A data base for FDD reservoirs for the Louisiana and Texas Gulf Coast Region was developed by LSU and SAIC. This data base includes reservoir parameters and performance data for reservoirs with significant production and OOIP volumes that are amenable to CO{sub 2} injection. A paper discussing the Port Neches CO{sub 2} project was presented at the 1996 SPE/DOE Symposium on Improved Oil Recovery.

  14. Improved efficiency of miscible CO{sub 2} floods and enhanced prospects for CO{sub 2} flooding heterogeneous reservoirs. Quarterly technical progress report, April 1, 1996--June 30, 1996

    SciTech Connect

    Schechter, D.S.

    1996-07-20

    Progress has been made in each of the three project areas during this quarter. Each quarter we are highlighting one project area. This quarter, Task 2 is highlighted with expanded details. Significant progress has been made this quarter in testing the functionalities of the foam-durability apparatus for assessment of foam properties at reservoir conditions. Another surfactant, Alipal{reg_sign} CD-128 at a concentration of 1000 ppm, was used for core flooding experiments. The foam mobility data showed a significant reduction of CO{sub 2} mobility and a favorable mobility dependence on rock permeability. Two slim tube test series and continuous phase equilibrium were done to examine the effects of pressure, temperature, and oil composition on oil displacement efficiency. A new series of core foam tests were completed to study the effects of flow rate, CO{sub 2} fraction (foam) quality, and rock permeability on foam-flow behavior. We are in the process of moving the foam reservoir simulator MASTER from a workstation to a Pentium PC environment and test MASTER on a 166 MHz Pentium PC. IFT of CO{sub 2}/crude oil has been measured using our pendant drop measurement system at 138{degrees}F and pressures from 850 psig to 2200 psig. The CO{sub 2} gravity drainage experiment that is in progress using a 50md Berea core at 138{degrees}F and pressures from 1700 to 2000 psig has reached 48% oil recovery and is continuing to increase. The mathematical model developed previously matches the experimental response accurately.

  15. Floods

    MedlinePlus

    Floods are common in the United States. Weather such as heavy rain, thunderstorms, hurricanes, or tsunamis can ... is breached, or when a dam breaks. Flash floods, which can develop quickly, often have a dangerous ...

  16. Gas miscible displacement enhanced oil recovery: Technology status report

    SciTech Connect

    Watts, R.J.; Komar, C.A.

    1989-01-01

    Research on gas flooding and miscible displacement, with an emphasis on improvement of CO/sub 2/ flood performance is described. Low reservoir volumetric sweep efficiency is the major problem associated with gas flooding and all miscible displacements. CO/sub 2/ flooding would be considerably more efficient if a larger area of the reservoir could be contacted by the gas. Current research has focused on mobility control, computer simulation, and reservoir heterogeneity studies. Three mobility control methods have been investigated: the use of polymers for direct thickening of high-density carbon dioxide, mobile ''foam-like dispersions'' of carbon dioxide and aqueous surfactant, and in situ deposition of chemical precipitates. 17 refs., 22 figs., 8 tabs.

  17. Defining Flood Recharge Processes: Lower Bill Williams River, Western Arizona

    NASA Astrophysics Data System (ADS)

    Simpson, S. C.; Meixner, T.; Hogan, J.

    2008-12-01

    River networks provide hydrologic connections between upland and headwater catchments and downstream reaches. In arid and semi-arid regions, full connectivity of a river system is rare and moments of connection may only occur during large flood events. Here we investigate the Bill Williams River, among the most arid river basins in the United States. The aridity of this system-and the associated lack of complicating hillslope processes adjacent to the river-provides a unique opportunity to study flood recharge processes in relative isolation. During all but the highest flows, the river infiltrates completely at the east end of Planet Valley and reemerges at the west end where it enters the Bill Williams River National Wildlife Refuge (NWR). Determining the source of baseflow in the lower Bill Williams/NWR, and the residence time of this water in the Planet Valley aquifer, will provide insight into the dependence of streamflow on earlier recharge-inducing floods. Defining this dependence more clearly is the next step toward a detailed knowledge of the long-term, basin-scale impacts of floods on water quality and quantity. To determine the impact of floods and the recharge they induce, surface and groundwater samples were collected during high and low flows throughout the basin from April 2007 through the present. Isotopic (δ18OH2O, δ2HH2O) and chemical differences (most notably SO4) in streamflow and groundwater along the system indicate the importance of older groundwater in NWR baseflow-either in the form of prior flood recharge or influxes from local springs. Sulfate isotope analysis (δ34SSO4, δ18OSO4) is pending for samples throughout the lower basin and this information should allow streamflow sources to be defined and quantified. This study provides a better characterization of the hydrologic and hydrochemical behavior of a Basin and Range river, and allows the effects of flood recharge processes to be more clearly defined at the basin scale.

  18. Post waterflood CO{sub 2} miscible flood in light oil fluvial: Dominated deltaic reservoirs. Third quarterly report, April 1, 1995--June 30, 1995

    SciTech Connect

    1995-07-15

    Production from the Marg Area 1 at Port Neches is averaging 337 BOPD for this quarter. The production drop is due to fluctuation in both GOR and BS&W on various producing wells, low water injectivity in the reservoir and shut-in one producing well to perform a workover to replace a failed gravel pack setting. Coil tubing work was performed on 2 injection wells in order to resume injection of water and CO{sub 2} in the reservoir. The Marg Area 2 did not respond favorably to CO{sub 2} injection in the Kuhn No. 6 well. For this reason Texaco will not pursue any further development of this section of the reservoir due mainly to low target reserves. Instead Texaco will reallocate the money to a new Marg segment (Marg Area 3) in order to test a new process that will utilize the CO{sub 2} to accelerate the primary production rates and reduce cycle time. Also the process should reduce water disposal cost, cash lifting cost, operating cost and increase the NPV of the reserves.

  19. Post waterflood CO2 miscible flood in light oil fluvial - dominated deltaic reservoirs. Technical progress report, October 1, 1994--December 30, 1994. 1st Quarter, fiscal year 1995

    SciTech Connect

    1994-01-15

    Production is averaging about 450 BOPD for the quarter. The fluctuation was primarily due to a temporary shutdown of CO{sub 2} delivery and maturing of the first WAG cycle. CO{sub 2} and water injection were reversed again in order to optimize changing yields and water cuts in the producing wells. Measured BHP was close to the anticipated value. A limited CO{sub 2} volume of 120 MMCF was injected to stimulate well Kuhn No. 6 to test the Huff-Puff process, since the well did not respond to CO{sub 2} injection from the main reservoir. The well will be placed on February 1, 1995. Total CO{sub 2} injection averaged this quarter about 8.8 MMCFD, including 3.6 MMCFD purchased CO{sub 2} from Cardox. The stratigraphy of the sand deposits is also discussed.

  20. Flooding and Flood Management

    USGS Publications Warehouse

    Brooks, K.N.; Fallon, J.D.; Lorenz, D.L.; Stark, J.R.; Menard, Jason

    2011-01-01

    Floods result in great human disasters globally and nationally, causing an average of $4 billion of damages each year in the United States. Minnesota has its share of floods and flood damages, and the state has awarded nearly $278 million to local units of government for flood mitigation projects through its Flood Hazard Mitigation Grant Program. Since 1995, flood mitigation in the Red River Valley has exceeded $146 million. Considerable local and state funding has been provided to manage and mitigate problems of excess stormwater in urban areas, flooding of farmlands, and flood damages at road crossings. The cumulative costs involved with floods and flood mitigation in Minnesota are not known precisely, but it is safe to conclude that flood mitigation is a costly business. This chapter begins with a description of floods in Minneosta to provide examples and contrasts across the state. Background material is presented to provide a basic understanding of floods and flood processes, predication, and management and mitigation. Methods of analyzing and characterizing floods are presented because they affect how we respond to flooding and can influence relevant practices. The understanding and perceptions of floods and flooding commonly differ among those who work in flood forecasting, flood protection, or water resource mamnagement and citizens and businesses affected by floods. These differences can become magnified following a major flood, pointing to the need for better understanding of flooding as well as common language to describe flood risks and the uncertainty associated with determining such risks. Expectations of accurate and timely flood forecasts and our ability to control floods do not always match reality. Striving for clarity is important in formulating policies that can help avoid recurring flood damages and costs.

  1. Study of hydrocarbon miscible solvent slug injection process for improved recovery of heavy oil from Schrader Bluff Pool, Milne Point Unit, Alaska. Annual report, January 1, 1994--December 31, 1994

    SciTech Connect

    Sharma, G.D.

    1995-07-01

    Alaska is the second largest oil producing state in the nation and currently contributes nearly 24% of the nations oil production. It is imperative that Alaskan heavy oil fields be brought into production. Schrader Bluff reservoir, located in the Milne Point Unit, which is part of the heavy oil field known as West Sak is estimated to contain 1.5 billion barrels of (14 to 21 degree API) oil-in-place. The field is currently under production by primary depletion. The eventual implementation of enhanced oil recovery (EOR) techniques will be vital for the recovery of additional oil from this reservoir. The availability of hydrocarbon gases (solvents) on the Alaska North Slope make the hydrocarbon miscible solvent injection process an important consideration for the EOR project in Schrader Bluff reservoir. Since Schrader Bluff oil is heavy and viscous, a water-alternating-gas (WAG) type of process for oil recovery is appropriate since such a process tends to derive synergetic benefits from both water injection (which provides mobility control and improvement in sweep efficiency) and miscible gas injection (which provides improved displacement efficiency). A miscible solvent slug injection process rather than continuous solvent injection is considered appropriate. Slim tube displacement studies, PVT data and asphaltene precipitation studies are needed for Schrader bluff heavy oil to define possible hydrocarbon solvent suitable for miscible solvent slug displacement process. Coreflood experiments are also needed to determine the effect of solvent slug size, WAG ratio and solvent composition on the recovery and solvent breakthrough. A compositional reservoir simulation study will be conducted later to evaluate the complete performance of the hydrocarbon solvent slug process and to assess the feasibility of this process for improving recovery of heavy oil from Schrader Bluff reservoir.

  2. Liquid Phase Miscibility Gap Materials

    NASA Technical Reports Server (NTRS)

    Gelles, S. H.; Markworth, A. J.

    1985-01-01

    The manner in which the microstructural features of liquid-phase miscibility gap alloys develop was determined. This will allow control of the microstructures and the resultant properties of these alloys. The long-duration low gravity afforded by the shuttle will allow experiments supporting this research to be conducted with minimal interference from buoyancy effects and gravitationally driven convection currents. Ground base studies were conducted on Al-In, Cu-Pb, and Te-Tl alloys to determine the effect of cooling rate, composition, and interfacial energies on the phase separation and solidification processes that influence the development of microstructure in these alloys. Isothermal and directional cooling experiments and simulations are conducted. The ground based activities are used as a technological base from which flight experiments formulated and to which these flight experiments are compared.

  3. USING PHASE DIAGRAMS TO PREDICT THE PERFORMANCE OF COSOLVENT FLOODS FOR NAPL REMEDIATION

    EPA Science Inventory

    Cosolvent flooding using water miscible solvents such as alcohols has been proposed as an in-situ NAPL remediation technique. This process is conceptually similar to enhanced oil recovery (EOR) using alcohols and some surfactant formulations. As a result of interest in the EOR ...

  4. Judy Creed CO/sub 2/ flood performance predictions

    SciTech Connect

    Delaney, R.P.; Fish, R.M.

    1980-01-01

    This work describes the studies which have been completed to evaluate the oil recovery benefits of a carbon dioxide miscible flood of the Judy Creek Beaverhill Lake, a pool in N. Alberta. Purchased and reproduced carbon dioxide will be injected into the reservoir to achieve the planned high volumes of carbon dioxide injection of over 50% pv. Laboratory tests, including slim tube displacement tests, pvt analysis, and a core flood, were conducted to determine carbon dioxide and oil properties along with the characteristics of the displacement process under a carbon dioxide flood. Conventional black oil simulation was used to model a statistical representation of the reservoir with adjustments for reservoir continuity, carbon dioxide dissolution in water, and miscible effects. These results indicated an incremental recovery over waterflood of 20% of the original oil in place.

  5. Flood risk under future climate in data sparse regions: Linking extreme value models and flood generating processes

    NASA Astrophysics Data System (ADS)

    Tramblay, Yves; Amoussou, Ernest; Dorigo, Wouter; Mahé, Gil

    2014-11-01

    For many areas in the world, there is a need for future projections of flood risk in order to improve the possible mitigation actions. However, such an exercise is often made difficult in data-sparse regions, where the limited access to hydrometric data does not allow calibrating hydrological models in a robust way under non-stationary conditions. In this study we present an approach to estimate possible changes in flood risks, which incorporates flood generating processes into statistical models for extreme values. This approach is illustrated for a West African catchment, the Mono River (12,900 km2), with discharge, precipitation and temperature data available between 1988 and 2010 and where the dominant flood generating process is soil saturation. A soil moisture accounting (SMA) model, calibrated against a merged surface soil moisture microwave satellite dataset, is used to estimate the annual maximum soil saturation level that is related to the location parameter of a generalized extreme value model of annual maximum discharge. With such a model, it is possible to estimate the changes in flood quantiles from the changes in the annual maximum soil saturation level. An ensemble of regional climate models from the ENSEMBLES-AMMA project are then considered to estimate the potential future changes in soil saturation and subsequently the changes in flood risks for the period 2028-2050. A sensitivity analysis of the non-stationary flood quantiles has shown that with the projected changes on precipitation (-2%) and temperature (+1.22°) under the scenario A1B, the projected flood quantiles would stay in the range of the observed variability during 1988-2010. The proposed approach, relying on low data requirements, could be useful to estimate the projected changes in flood risks for other data-sparse catchments where the dominant flood-generating process is soil saturation.

  6. Enhancing flood forecasting with the help of processed based calibration

    NASA Astrophysics Data System (ADS)

    Cullmann, Johannes; Krauße, Thomas; Philipp, Andy

    Due to the fact that the required input data are not always completely available and model structures are only a crude description of the underlying natural processes, model parameters need to be calibrated. Calibrated model parameters only reflect a small domain of the natural processes well. This imposes an obstacle on the accuracy of modelling a wide range of flood events, which, in turn is crucial for flood forecasting systems. Together with the rigid model structures of currently available rainfall-runoff models this presents a serious constraint to portraying the highly non-linear transformation of precipitation into runoff. Different model concepts (interflow, direct runoff), or rather the represented processes, such as infiltration, soil water movement etc. are more or less dominating different sections of the runoff spectrum. Most models do not account for such transient characteristics inherent to the hydrograph. In this paper we try to show a way out of the dilemma of limited model parameter validity. Exemplarily, we investigate on the model performance of WaSiM-ETH, focusing on the parameterisation strategy in the context of flood forecasting. In order to compensate for the non-transient parameters of the WaSiM model we propose a process based parameterisation strategy. This starts from a detailed analysis of the considered catchments rainfall-runoff characteristics. Based on a classification of events, WaSiM-ETH is calibrated and validated to describe all the event classes separately. These specific WaSiM-ETH event class models are then merged to improve the model performance in predicting peak flows. This improved catchment modelling can be used to train an artificial intelligence based black box forecasting tool as described in [Schmitz, G.H., Cullmann, J., Görner, W., Lennartz, F., Dröge, W., 2005. PAI-OFF: Eine neue Strategie zur Hochwasservorhersage in schnellreagierenden Einzugsgebieten. Hydrologie und Wasserbewirtschaftung 49, 226

  7. Transient Interfacial Phenomena in Miscible Polymer Systems (TIPMPS)

    NASA Technical Reports Server (NTRS)

    Pojman, John A.; Bessonov, Nicholas; Volpert, Vitaly; Wilke, Hermann

    2003-01-01

    Almost one hundred years ago Korteweg published a theory of how stresses could be induced in miscible fluids by concentration gradients, causing phenomena that would appear to be the same as with immiscible fluids. Miscible fluids could manifest a transient or effective interfacial tension (EIT). To this day, there has been no definitive experiment to confirm Korteweg's model but numerous fascinating and suggestive experiments have been reported. The goal of TIPMPS is to answer the question: Can concentration and temperature gradients in miscible materials induce stresses that cause convection? Many polymer processes involving miscible monomer and polymer systems could be affected by fluid flow and so this work could help understand miscible polymer processing, not only in microgravity, but also on earth. Demonstrating the existence of this phenomenon in miscible fluids will open up a new area of study for materials science. The science objectives of TIPMPS are: (1) Determine if convection can be induced by variation of the width of a miscible interface; (2) Determine if convection can be induced by variation of temperature along a miscible interface; (3) Determine if convection can be induced by variation of conversion along a miscible interface An interface between two miscible fluids can best be created via a spatially-selective photopolymerization of dodecyl acrylate with a photoinitiator, which allows the creation of precise and accurate concentration gradients between polymer and monomer. Optical techniques will be used to measure the refractive index variation caused by the resultant temperature and concentration fields. The viscosity of the polymer will be measured from the increase in the fluorescence of pyrene. Because the large concentration and temperature gradients cause buoyancy-driven convection that prevents the observation of the predicted flows, the experiment must be done in microgravity. In this report, we will consider our efforts to estimate

  8. Interpretations of Polymer-Polymer Miscibility.

    ERIC Educational Resources Information Center

    Olabisi, Olagoke

    1981-01-01

    Discusses various aspects of polymeric mixtures, mixtures of structurally different homopolymers, copolymers, terpolymers, and the like. Defines concepts of polymer-polymer miscibility from practical and theoretical viewpoints, and ways of predicting such miscibility. (JN)

  9. Partial Miscibility in Copolymer Blends

    NASA Astrophysics Data System (ADS)

    Clark, Elizabeth; Lipson, Jane

    2011-03-01

    Copolymers can be used to affect the miscibility of otherwise immiscible polymer blends by acting as compatibilizers. To better understand the energetics of these types of systems, we use a simple lattice model to study phase separation in binary copolymer/homopolymer blends. We focus on a copolymer that contains both A and B type monomers and a homopolymer that contains purely A type monomer. An example of a system that we are investigating is polyethylene mixed with either random or alternating poly(ethylene-co-propylene). The sequence effect on miscibility as the copolymer microstructure is varied from random to alternating is investigated as well. The support of GAANN is gratefully acknowledged.

  10. Evidence of a miscibility gap in the FeTe1-xSex polycrystalline samples prepared with a melting process

    NASA Astrophysics Data System (ADS)

    Sala, A.; Palenzona, A.; Bernini, C.; Caglieris, F.; Cimberle, M. R.; Ferdeghini, C.; Lamura, G.; Martinelli, A.; Pani, M.; Hecher, J.; Eisterer, M.; Putti, M.

    2014-05-01

    The study of overdoped FeTe1-xSex (0.5 < x < 1) polycrystalline superconductor samples is reported. The samples were prepared using a melting technique previously developed by our group. Increasing the Se content a phase separation related to the formation of FeSe inside the Fe(Se,Te) phase happens, as demonstrated by structural analysis and magnetic characterization. The proposed phase separation picture is likely the fingerprint of a miscibility gap in the Fe(Se,Te) system.

  11. Field Experiments Aimed To The Analysis of Flood Generation Processes

    NASA Astrophysics Data System (ADS)

    Carriero, D.; Iacobellis, V.; Oliveto, G.; Romano, N.; Telesca, V.; Fiorentino, M.

    The study of the soil moisture dynamics and of the climate-soil-vegetation interac- tion is essential for the comprehension of possible climatic change phenomena, as well as for the analysis of occurrence of extreme hydrological events. In this trend the theoretically-based distribution of floods recently derived by Fiorentino and Ia- cobellis, [ŞNew insights about the climatic and geologic control on the probability distribution of floodsT, Water Resources Research, 2001, 37: 721-730] demonstrated, by an application in some Southern Italy basins, that processes at the hillslope scale strongly influence the basin response by means of the different mechanisms of runoff generation produced by various distributions of partial area contributing. This area is considered as a stochastic variable whose pdf position parameter showed strong de- pendence on the climate as it can seen in the studied basins behavior: in dry zones, where there is the prevalence of the infiltration excess (Horton) mechanism, the basin water loss parameter decreases as basin area increases and the flood peak source area depends on the permeability of soils; in humid zones, with the prevalence of satu- ration excess (Dunne) process, the loss parameter seems independent from the basin area and very sensitive to simple climatic index while only small portion of the area invested by the storm contributes to floods. The purpose of this work is to investigate the consistency of those interpretations by means of field experiments at the hillslope scale to establish a parameterization accounting for soil physical and hydraulic prop- erties, vegetation characteristics and land-use. The research site is the catchment of River Fiumarella di Corleto, which is located in Basilicata Region, Italy, and has a drainage area of approximately 32 km2. The environment has a rather dynamic geo- morphology and very interesting features from the soil-landscape modeling viewpoint [Santini A., A. Coppola, N. Romano, and

  12. A process flood typology along an Alpine transect: analysis based on observations and modelling approaches

    NASA Astrophysics Data System (ADS)

    Zoccatelli, Davide; Parajka, Juraj; Gaál, Ladislav; Blöschl, Günter; Borga, Marco

    2014-05-01

    Understanding the effects of climate changes on river floods requires a better understanding of the control of climate variability on flood regimes. The aim of this work is to identify the process types of causative mechanisms of floods along a longitudinal Alpine transect spanning 200 km from Verona in Italy to lower Germany. The investigation is focused on the analysis of the statistical properties of the various flood typologies, their spatial organization and their relation with the topography of the transect. Along the transect, 34 basins were selected following criteria of basin size (between 50 and 500 km2), amount of hydrometeorological data available and impact of hydraulic structures on runoff regime. Around 20 years of hourly data of discharge, precipitation and temperature were collected for each basin. The three most intense floods occurred each year are considered in the work. Precipitation and temperature follow a sharp gradient across the transect, with both precipitation and temperature low around the main alpine ridge. Four flood types are considered: long-rain floods, flash floods, rain-on-snow floods, and snowmelt floods. For the classification we use a combination of a number of process indicators, including the timing of the floods, storm duration, rainfall depths, snowmelt contribution to runoff, initial catchment state and runoff response dynamics, using a procedure similar to what described in Merz and Blöschl (2003). The indicators for flood classification are derived based on either observed discharge data and model results. Comparison between the two derived flood classifications allows one to analyse the viability of using a model approach to build flood typologies in basins characterized by varying data availability. Finally, a sensitivity analysis is carried out by imposing step changes to the precipitation and temperature pattern. The resulting distribution of flood types gives an insight on the possible change in floods

  13. Process-based distributed hydrological modelling of annual floods in the Upper Zambezi using the Desert Flood Index

    NASA Astrophysics Data System (ADS)

    Meinhardt, Markus; Sven, Kralisch; Manfred, Fink; Daniel, Butchart-Kuhlmann; Anthony, Chabala; Melanie, Fleischer; Jörg, Helmschrot; Wilson, Phiri; Tina, Trautmann; Henry, Zimba; Imasiku, Nyambe

    2016-04-01

    Wetland areas are especially sensitive to changes in hydrological conditions. The catchment of the Luanginga River, a tributary of the Upper Zambezi which covers about 33000 km², shows this characteristic in an exemplary way. Ranging from the Angolan highlands to the Barotse floodplain of the Zambezi River , it is characterized by an annual flow regime and extensive wetland areas. Due to its annual flooding with peak times in April, the area features exceptionally fertile soils with high agricultural production and is further known for its rich cultural heritage, making it especially sensitive to changes of hydrological conditions . To identify possible changes related to projected climate and land management change, especially in the area of the floodplain, there is a need to apply a process-based distributed hydrological model of the annual floods . Remote sensing techniques have shown to be appropriate to identify the extend of the important flooding and were used to validate the model in space and time. The results of this research can be used as a basis with which to provide evidence-based advice and information for all decision-makers and stakeholders in the region. For this assessment , such a modelling approach is applied to adequately represent hydrological processes and to address key water resources management issues at sub-basin levels. Introducing a wetland simulation extension, the model allows to represent the annual flood regime of the system and thus to address the effect of climate change and upstream land use changes on flow regimes in the downstream watershed. In order to provide a basis for model validation and calibration, the inundated area was determined using the Desert Flood Index (DFI), which was generated from a time series of Landsat images. We will give a short introduction to the study area and related water resources management problems, present the intended model structure and show first simulations and model validation results

  14. Phase separation in transparent liquid-liquid miscibility gap systems

    NASA Technical Reports Server (NTRS)

    Gelles, S. H.; Bhat, B. N.; Laub, R. J.

    1979-01-01

    A program to be carried out on transparent liquid-phase miscibility gap materials was developed for the purpose of acquiring additional insight into the separation process occurring in these systems. The transparency feature allows the reaction to be viewed directly through light scattering and holographic methods.

  15. Insurance against climate change and flood risk: Insurability and decision processes of insurers

    NASA Astrophysics Data System (ADS)

    Hung, Hung-Chih; Hung, Jia-Yi

    2016-04-01

    1. Background Major portions of the Asia-Pacific region is facing escalating exposure and vulnerability to climate change and flood-related extremes. This highlights an arduous challenge for public agencies to improve existing risk management strategies. Conventionally, governmental funding was majorly responsible and accountable for disaster loss compensation in the developing countries in Asia, such as Taiwan. This is often criticized as an ineffective and inefficient measure of dealing with flood risk. Flood insurance is one option within the toolkit of risk-sharing arrangement and adaptation strategy to flood risk. However, there are numerous potential barriers for insurance companies to cover flood damage, which would cause the flood risk is regarded as uninsurable. This study thus aims to examine attitudes within the insurers about the viability of flood insurance, the decision-making processes of pricing flood insurance and their determinants, as well as to examine potential solutions to encourage flood insurance. 2. Methods and data Using expected-utility theory, an insurance agent-based decision-making model was developed to examine the insurers' attitudes towards the insurability of flood risk, and to scrutinize the factors that influence their decisions on flood insurance premium-setting. This model particularly focuses on how insurers price insurance when they face either uncertainty or ambiguity about the probability and loss of a particular flood event occurring. This study considers the factors that are expected to affect insures' decisions on underwriting and pricing insurance are their risk perception, attitudes towards flood insurance, governmental measures (e.g., land-use planning, building codes, risk communication), expected probabilities and losses of devastating flooding events, as well as insurance companies' attributes. To elicit insurers' utilities about premium-setting for insurance coverage, the 'certainty equivalent,' 'probability

  16. Vistula River bed erosion processes and their influence on Warsaw's flood safety

    NASA Astrophysics Data System (ADS)

    Magnuszewski, A.; Moran, S.

    2015-03-01

    Large cities have historically been well protected against floods as a function of their importance to society. In Warsaw, Poland, located on a narrow passage of the Vistula River valley, urban flood disasters were not unusual. Beginning at the end of the 19th century, the construction of river embankment and training works caused the narrowing of the flood passage path in the downtown reach of the river. The process of bed erosion lowered the elevation of the river bed by 205 cm over the 20th century, and the consequences of bed lowering are reflected by the rating curve change. Conditions of the flood passage have been analysed by the CCHE2D hydrodynamic model both in retro-modelling and scenario simulation modelling. The high water mark of the 1844 flood and iterative calculations in retro-modelling made possible estimation of the discharge, Q = 8250 m3 s-1. This highest observed historical flood in a natural river has been compared to recent conditions of the Vistula River in Warsaw by scenario modelling. The result shows dramatic changes in water surface elevation, velocities, and shear stress. The vertical velocity in the proximity of Port Praski gauge at km 513 can reach 3.5 m s-1, a very high value for a lowland river. The average flow conveyance is improving due to channel erosion but also declining in the case of extreme floods due to high resistance from vegetation on the flood plains.

  17. Novel Shapes of Miscible Interfaces Observed

    NASA Technical Reports Server (NTRS)

    Balasubramaniam, Ramaswamy; Rashidnia, Nasser

    2001-01-01

    The dynamics of miscible displacements in a cylindrical tube are being investigated experimentally and numerically, with a view to understand the complex processes that occur, for example, in enhanced oil recovery, hydrology, and filtration. We have observed complex shapes of the interface between two liquids that mix with each other when the less viscous liquid is displaced by the more viscous one in a tube. A less viscous fluid that displaces a more viscous fluid is known to propagate in the form of a "finger," and a flight experiment proposed by Maxworthy et al. to investigate the miscible-interface dynamics is currently being developed by NASA. From the current theory of miscible displacements, which was developed for a porous medium satisfying Darcy's law, it can be shown that in the absence of gravity the interface between the fluids is destabilized and thus susceptible to fingering only when a more viscous fluid is displaced by a less viscous one. Therefore, if the interface is initially flat and the more viscous fluid displaces the less viscous fluid, the interface ought to be stable and remain flat. However, numerical simulations by Chen and Meiburg for such displacement in a cylindrical tube show that the interface is unstable and a finger of the more viscous fluid is indeed formed. Preliminary experiments performed at the NASA Glenn Research Center show that not only can fingering occur when the more viscous fluid displaces a less viscous one in a cylindrical tube, but also that under certain conditions the advancing finger achieves a sinuous or snakelike shape. These experiments were performed using silicone oils in a vertical pipette of small diameter. In the initial configuration, the more viscous fluid rested on top of the less viscous one, and the interface was nominally flat. A dye was added to the upper liquid for ease of observation of the interface between the fluids. The flow was initiated by draining the lower fluid from the bottom of the

  18. Spatial Analytic Hierarchy Process Model for Flood Forecasting: An Integrated Approach

    NASA Astrophysics Data System (ADS)

    Nasir Matori, Abd; Umar Lawal, Dano; Yusof, Khamaruzaman Wan; Hashim, Mustafa Ahmad; Balogun, Abdul-Lateef

    2014-06-01

    Various flood influencing factors such as rainfall, geology, slope gradient, land use, soil type, drainage density, temperature etc. are generally considered for flood hazard assessment. However, lack of appropriate handling/integration of data from different sources is a challenge that can make any spatial forecasting difficult and inaccurate. Availability of accurate flood maps and thorough understanding of the subsurface conditions can adequately enhance flood disasters management. This study presents an approach that attempts to provide a solution to this drawback by combining Geographic Information System (GIS)-based Analytic Hierarchy Process (AHP) model as spatial forecasting tools. In achieving the set objectives, spatial forecasting of flood susceptible zones in the study area was made. A total number of five set of criteria/factors believed to be influencing flood generation in the study area were selected. Priority weights were assigned to each criterion/factor based on Saaty's nine point scale of preference and weights were further normalized through the AHP. The model was integrated into a GIS system in order to produce a flood forecasting map.

  19. Study of hydrocarbon miscible solvent slug injection process for improved recovery of heavy oil from Schrader Bluff Pool, Milne Point Unit, Alaska. Annual report, December 1, 1992--December 31, 1993

    SciTech Connect

    Sharma, G.D.

    1994-01-01

    The shallow Cretaceous sands of the Schrader Bluff Reservoir occur between depths of 4,000 and 4,800 feet below surface and are estimated to contain up to 1.5 billion barrels of oil in place. The field is currently under production by primary depletion. Initial production indicated that primary recovery will fall short of earlier estimates and waterflooding will have to be employed much earlier than expected. A large portion of the oil-in-place thus would still be left behind in this reservoir after primary and secondary recovery methods have been applied. Enhanced oil recovery (EOR) techniques will be needed to recover the additional portion of remaining oil in this huge reservoir and to add significant additional reserves. Slim tube displacement studies, PVT data and asphaltene precipitation studies are needed for Schrader Bluff heavy oil to define possible hydrocarbon solvent suitable for miscible solvent slug displacement process. Such studies are essential because the API gravity of the crude in Schrader Bluff reservoir varies significantly from well to well. Coreflood experiments are also needed to determine effect of solvent slug size, WAG ratio and solvent composition on the oil recovery and solvent breakthrough. A compositional reservoir simulation study will be conducted later to evaluate the complete performance of the hydrocarbon solvent slug process and to assess the feasibility of this process for improving recovery of heavy oil from Schrader Bluff reservoir. This report contains the following: reservoir description; slim tube displacement studies; and coreflood experiments.

  20. Two glass transitions in miscible polymer blends?

    SciTech Connect

    Dudowicz, Jacek; Freed, Karl F.; Douglas, Jack F.

    2014-06-28

    In contrast to mixtures of two small molecule fluids, miscible binary polymer blends often exhibit two structural relaxation times and two glass transition temperatures. Qualitative explanations postulate phenomenological models of local concentration enhancements due to chain connectivity in ideal, fully miscible systems. We develop a quantitative theory that explains qualitative trends in the dynamics of real miscible polymer blends which are never ideal mixtures. The theory is a synthesis of the lattice cluster theory of blend thermodynamics, the generalized entropy theory for glass-formation in polymer materials, and the Kirkwood-Buff theory for concentration fluctuations in binary mixtures.

  1. Voice-enabled Knowledge Engine using Flood Ontology and Natural Language Processing

    NASA Astrophysics Data System (ADS)

    Sermet, M. Y.; Demir, I.; Krajewski, W. F.

    2015-12-01

    The Iowa Flood Information System (IFIS) is a web-based platform developed by the Iowa Flood Center (IFC) to provide access to flood inundation maps, real-time flood conditions, flood forecasts, flood-related data, information and interactive visualizations for communities in Iowa. The IFIS is designed for use by general public, often people with no domain knowledge and limited general science background. To improve effective communication with such audience, we have introduced a voice-enabled knowledge engine on flood related issues in IFIS. Instead of navigating within many features and interfaces of the information system and web-based sources, the system provides dynamic computations based on a collection of built-in data, analysis, and methods. The IFIS Knowledge Engine connects to real-time stream gauges, in-house data sources, analysis and visualization tools to answer natural language questions. Our goal is the systematization of data and modeling results on flood related issues in Iowa, and to provide an interface for definitive answers to factual queries. The goal of the knowledge engine is to make all flood related knowledge in Iowa easily accessible to everyone, and support voice-enabled natural language input. We aim to integrate and curate all flood related data, implement analytical and visualization tools, and make it possible to compute answers from questions. The IFIS explicitly implements analytical methods and models, as algorithms, and curates all flood related data and resources so that all these resources are computable. The IFIS Knowledge Engine computes the answer by deriving it from its computational knowledge base. The knowledge engine processes the statement, access data warehouse, run complex database queries on the server-side and return outputs in various formats. This presentation provides an overview of IFIS Knowledge Engine, its unique information interface and functionality as an educational tool, and discusses the future plans

  2. Surface Tension and Fingering of Miscible Interfaces

    NASA Technical Reports Server (NTRS)

    Abib, Mohammed; Liu, Jian-Bang; Ronney, Paul D.

    1999-01-01

    Experiments on miscible, buoyantly unstable reaction-diffusion fronts and non-reacting displacement fronts in Hele-Shaw cells show a fingering-type instability whose wavelengths (lambda*) are consistent with an interfacial tension (sigma) at the front caused by the change in chemical composition, even though the solutions are miscible in all proportions. In conjunction with the Saffman-Taylor model, the relation sigma = K/tau, where tau is the interface thickness and K approximately equal 4 +/- 2 x 10(exp -6) dyne, enables prediction of our measured values of lambda* as well as results from prior experiments on miscible interfaces. These results indicate that even for miscible fluids, surface tension is generally a more significant factor than diffusion in interfacial stability and flow characteristics.

  3. A regional look at the selection of a process-oriented model for flood peak/volume relationships

    NASA Astrophysics Data System (ADS)

    Szolgay, Ján; Gaál, Ladislav; Bacigál, Tomáš; Kohnová, Silvia; Hlavčová, Kamila; Výleta, Roman; Blöschl, Günter

    2016-05-01

    Recent research on the bivariate flood peak/volume frequency analysis has mainly focused on the statistical aspects of the use of various copula models. The interplay of climatic and catchment processes in discriminating among these models has attracted less interest. In the paper we analyse the influence of climatic and hydrological controls on flood peak and volume relationships and their models, which are based on the concept of comparative hydrology in the catchments of a selected region in Austria. Independent flood events have been isolated and assigned to one of the three types of flood processes: synoptic floods, flash floods and snowmelt floods. First, empirical copulas are regionally compared in order to verify whether any flood processes are discernible in terms of the corresponding bivariate flood-peak relationships. Next the types of copulas, which are frequently used in hydrology are fitted, and their goodness-of-fit is examined in a regional scope. The spatial similarity of copulas and their rejection rate, depending on the flood type, region, and sample size are examined, too. In particular, the most remarkable difference is observed between flash floods and the other two types of flood. It is concluded that treating flood processes separately in such an analysis is beneficial, both hydrologically and statistically, since flood processes and the relationships associated with them are discernible both locally and regionally in the pilot region. However, uncertainties inherent in the copula-based bivariate frequency analysis itself (caused, among others, also by the relatively small sample sizes for consistent copula model selection, upper tail dependence characterization and reliable predictions) may not be overcome in the scope of such a regional comparative analysis.

  4. Viscous fingering with partial miscible fluids

    NASA Astrophysics Data System (ADS)

    Fu, Xiaojing; Cueto-Felgueroso, Luis; Juanes, Ruben

    2015-11-01

    When a less viscous fluid displaces a more viscous fluid, the contrast in viscosity destabilizes the interface between the two fluids, leading to the formation of fingers. Studies of viscous fingering have focused on fluids that are either fully miscible or perfectly immiscible. In practice, however, the miscibility of two fluids can change appreciably with temperature and pressure, and often falls into the case of partial miscibility, where two fluids have limited solubility in each other. Following our recent work for miscible (Jha et al., PRL 2011, 2013) and immiscible systems (Cueto-Felgueroso and Juanes, PRL 2012, JFM 2014), here we propose a phase-field model for fluid-fluid displacements in a Hele-Shaw cell, when the two fluids have limited (but nonzero) solubility in one another. Partial miscibility is characterized through the design of thermodynamic free energy of the two-fluid system. We elucidate the key dimensionless groups that control the behavior of the system. We present high-resolution numerical simulations of the model applied to the viscous fingering problem. On one hand, we demonstrate the effect of partial miscibility on the hydrodynamic instability. On the other, we elucidate the role of the degree of fingering on the rate of mutual fluid dissolution.

  5. An integrated process for the production of platform chemicals and diesel miscible fuels by acid-catalyzed hydrolysis and downstream upgrading of the acid hydrolysis residues with thermal and catalytic pyrolysis.

    PubMed

    Girisuta, Buana; Kalogiannis, Konstantinos G; Dussan, Karla; Leahy, James J; Hayes, Michael H B; Stefanidis, Stylianos D; Michailof, Chrysa M; Lappas, Angelos A

    2012-12-01

    This study evaluates an integrated process for the production of platform chemicals and diesel miscible biofuels. An energy crop (Miscanthus) was treated hydrothermally to produce levulinic acid (LA). Temperatures ranging between 150 and 200 °C, sulfuric acid concentrations 1-5 wt.% and treatment times 1-12 h were applied to give different combined severity factors. Temperatures of 175 and 200 °C and acid concentration of 5 wt.% were found to be necessary to achieve good yield (17 wt.%) and selectivities of LA while treatment time did not have an effect. The acid hydrolysis residues were characterized for their elemental, cellulose, hemicellulose and lignin contents, and then tested in a small-scale pyrolyzer using silica sand and a commercial ZSM-5 catalyst. Milder pretreatment yielded more oil (43 wt.%) and oil O(2) (37%) while harsher pretreatment and catalysis led to more coke production (up to 58 wt.%), less oil (12 wt.%) and less oil O(2) (18 wt.%). PMID:23073094

  6. Effects of vibrations on dynamics of miscible liquids

    NASA Astrophysics Data System (ADS)

    Gaponenko, Yu.; Shevtsova, V.

    2010-01-01

    We report on a numerical study of the mixing of two miscible fluids in gravitationally stable configuration. In the absence of external forces the diffusion process leads to the mixing of species. The aim of this study is to analyze the physical mechanism by which vibrations affect the mixing characteristic of two stratified miscible fluids. The translational periodic vibrations of a rigid cell filled with different mixtures of water-isopropanol are imposed. The vibrations with a constant frequency and amplitude are directed along the interface. In absence of gravity vibration-induced mass transport is incomparably faster than in diffusion regime. Our results highlight the strong interplay between gravity and vibrational impact, the relative weight of each effect is determined by ratio vibrational and classical Rayleigh numbers.

  7. Optical data processing and projected applications of the ERTS-1 imagery covering the 1973 Mississippi River Valley floods

    NASA Technical Reports Server (NTRS)

    Deutsch, M.; Ruggles, F. H.

    1974-01-01

    Flooding along the Mississippi River and some of its tributaries was imaged by the multispectral scanner (MSS) on the Earth Resources Technology Satellite (ERTS-1) on at least three orbits during the spring of 1973. The ERTS data provided the first opportunity for mapping the regional extent of flooding at the time the imagery was acquired. Special optical data processing techniques were used to produce a variety of multispectral color composites which enhanced floodplain details. One of these, a two-color composite of near infrared bands 6 and 7, was enlarged and registered to 1:250,000-scale topographic maps and used as the basis for preparation of flood image maps. Two specially filtered three-color composites of MSS bands 5, 6, and 7 and 4, 5, and 7 were prepared to aid in the interpretation of the data. The extent of the flooding was vividly depicted on a single image by two-color temporal composites produced on the additive-color viewer using band 7 flood data superimposed on pre-flood band 7 images. Analysis of temporal data composites of the pre-flood and post-flood band 7 images indicate that changes in surface reflectance characteristics caused by the flooding can be delineated, thus making it possible to map the overall area flooded without the necessity of a real-time system to track and image the peak flood waves.

  8. A process-based analysis of the suitability of copula types for peak-volume flood relationships

    NASA Astrophysics Data System (ADS)

    Szolgay, J.; Gaál, L.; Kohnová, S.; Hlavčová, K.; Výleta, R.; Bacigál, T.; Blöschl, G.

    2015-06-01

    The work aims at analyzing the bivariate relationship between flood peaks and flood volumes, with a particular focus on the type and seasonality of flood generation processes. Instead of the usual approach that deals with an analysis of the annual maxima of flood events, the current analysis includes all independent flood events in a catchment. Flood events are considered independent when they originate from distinguishably different synoptic/meteorological situations. The target region is located in the northern part of Austria, and consists of 72 small and mid-sized catchments. On the basis of the discharge measurements with a time resolution of 1 h from the period 1976-2007, independent flood events were identified and were assigned to one of the three following flood generation type categories: synoptic floods, flash floods and snowmelt floods. These were subsequently divided into two seasons, thereby separating predominantly rainfall-fed and snowmelt-fed floods. Nine frequently-used copula types were locally fitted to the samples of the flood type and seasonal data. Their goodness-of-fit was examined locally as well as analyzed in a regional scope. It was concluded that (i) treating flood processes separately is beneficial for the statistical analysis; (ii) suitability patterns of acceptable copula types are distinguishably different for the seasons/flood types considered, (iii) the Clayton and Joe copulas shows an unacceptable performance for all the seasons/flood types in the region; (iv) the rejection rate of the other copula types depends on the season/flood type and also on the sample size; (v) given that usually more than one statistically suitable dependence model exists, an uncertainty analysis of the design values in the engineering studies resulting from the choice of model seems unavoidable; (vi) reducing uncertainty in the choice of model could be attempted by a deeper hydrological analysis of the dependence structure between flood peaks and

  9. Post waterflood CO{sub 2} miscible flood in light oil, fluvial - dominated deltaic reservoirs. Technical progress report, 4th quarter, fiscal year 1994, July 1, 1994--September 30, 1994

    SciTech Connect

    Not Available

    1994-10-15

    Production from the Port Neches project has reached a new high of 500 BOPD, as shown. Production from several wells has improved after changing WAGer and CO{sub 2} injection patterns. The WAG process appears to be effective in FDD reservoirs. The WAT process has improved the oil production rates and simultaneously decreased the CO{sub 2} production rates from wells with high GOR. Material balance calculations indicate that the reservoir pressure remained relatively flat, and a new BHP will be taken this month to verify the calculations. Total CO{sub 2} injection is averaging about 9.5 MMCFD, including 3.9 MMCFD purchased from Cardox, as shown, and the balance is recycled from the producing wells. Over 50% of the gas was produced from one well, Khun No. 33. A CO{sub 2} injection line was installed to huff-puff well Khun No. 6 that did not respond yet to CO{sub 2} injection in well Khun No. 17. After injecting a limited CO{sub 2} volume in well Khun No. 6, this will be followed by a short shut-in period, then the well will be placed on production.

  10. Quantifying the effect of sea level rise and flood defence - a point process perspective on coastal flood damage

    NASA Astrophysics Data System (ADS)

    Boettle, M.; Rybski, D.; Kropp, J. P.

    2016-02-01

    In contrast to recent advances in projecting sea levels, estimations about the economic impact of sea level rise are vague. Nonetheless, they are of great importance for policy making with regard to adaptation and greenhouse-gas mitigation. Since the damage is mainly caused by extreme events, we propose a stochastic framework to estimate the monetary losses from coastal floods in a confined region. For this purpose, we follow a Peak-over-Threshold approach employing a Poisson point process and the Generalised Pareto Distribution. By considering the effect of sea level rise as well as potential adaptation scenarios on the involved parameters, we are able to study the development of the annual damage. An application to the city of Copenhagen shows that a doubling of losses can be expected from a mean sea level increase of only 11 cm. In general, we find that for varying parameters the expected losses can be well approximated by one of three analytical expressions depending on the extreme value parameters. These findings reveal the complex interplay of the involved parameters and allow conclusions of fundamental relevance. For instance, we show that the damage typically increases faster than the sea level rise itself. This in turn can be of great importance for the assessment of sea level rise impacts on the global scale. Our results are accompanied by an assessment of uncertainty, which reflects the stochastic nature of extreme events. While the absolute value of uncertainty about the flood damage increases with rising mean sea levels, we find that it decreases in relation to the expected damage.

  11. Quantifying the effect of sea level rise and flood defence - apoint process perspective on coastal flood damage

    NASA Astrophysics Data System (ADS)

    Boettle, M.; Rybski, D.; Kropp, J. P.

    2015-10-01

    In contrast to recent advances in projecting sea levels, estimations about the economic impact of sea level rise are vague. Nonetheless, they are of great importance for policy making with regard to adaptation and greenhouse-gas mitigation. Since the damage is mainly caused by extreme events, we propose a stochastic framework to estimate the monetary losses from coastal floods in a confined region. For this purpose, we follow a Peak-over-Threshold approach employing a Poisson point process and the Generalised Pareto Distribution. By considering the effect of sea level rise as well as potential adaptation scenarios on the involved parameters, we are able to study the development of the annual damage. An application to the city of Copenhagen shows that a doubling of losses can be expected from a mean sea level increase of only 11 cm. In general, we find that for varying parameters the expected losses can be well approximated by one of three analytical expressions depending on the extreme value parameters. These findings reveal the complex interplay of the involved parameters and allow conclusions of fundamental relevance. For instance, we show that the damage always increases faster than the sea level rise itself. This in turn can be of great importance for the assessment of sea level rise impacts on the global scale. Our results are accompanied by an assessment of uncertainty, which reflects the stochastic nature of extreme events. While the uncertainty of flood damage increases with rising sea levels, we find that the error of our estimations in relation to the expected damage decreases.

  12. Pore-scale simulation of miscible displacement in porous media using the lattice Boltzmann method

    NASA Astrophysics Data System (ADS)

    Xia, Ming

    2016-03-01

    A numerical model based on the lattice Boltzmann method is presented to investigate the viscous fingering phenomena of miscible displacement processes in porous media, which involves the fluid flow, heat transfer and mass transport. Especially, temperature- and concentration-dependent pore-fluid viscosity is considered. A complete list is derived and given for the conversion of relevant physical variables to lattice units to facilitate the understanding and implementation of the coupled problems involving fluid flow, heat transfer and mass transport using the LBM. To demonstrate the proposed model capacity, two different complex geometry microstructures using high resolution micro-computed tomography (micro-CT) images of core sample have been obtained and incorporated as computation geometries for modeling miscible displacement processes in porous media. The viscous fingering phenomena of miscible displacement processes are simulated in two different cases, namely in a channel and a porous medium respectively. Some influencing factors on the miscible displacement process, such as the pore-scale microstructure, Le number and Re number, are studied in great detail. The related simulation results have demonstrated that: (1) the existence of the pore-scale microstructure can have a significant effect on the front morphologies and front propagation speed in the miscible displacement process; (2) as the Le number increases, the fluid front and thermal front evolve differently, with the thermal front being less unstable due to more diffusion; (3) a larger Re number can lead to an increase in the propagation speed of the front.

  13. Processes and Geomorphological Impacts of an Extreme Flash Flood Event in SE Spain

    NASA Astrophysics Data System (ADS)

    Hooke, J.

    2015-12-01

    A major flash flood event took place on 28 September, 2012 in SE Spain, resulting in 10 fatalities and much damage to infrastructure regionally. The flood affected long-term monitoring sites in two catchments in which morphological changes and flow dynamics of these ephemeral channels were being measured. Thus detailed data on channel state prior to the flood were available. The flood event in the Nogalte catchment was extreme in its peak flow, rate of rise and unit runoff. The catchment has steep relief and much bare soil under almond groves, resulting in high sediment supply. The channel is confined in places, but mostly wide and braided, composed of loose gravel and occupying much of the valley floor. Flow was spatially continuous, with high connectivity throughout the catchment. The flood effects were net depositional in the monitored sites, with massive sedimentation on the channel bars. Vegetation was destroyed. Bank erosion and destruction of embankments took place in some locations. Hydraulic calculations indicate very high velocities, stream power and Froude numbers. Modelling and field evidence demonstrate extremely high sediment competence and sediment loadings. The influence of the event dynamics on processes and net outcomes is discussed. The impacts are compared with other events in this and neighbouring catchments. Overall, the event in the Nogalte did not alter the morphology markedly in spite of its extreme characteristics. It is suggested that these valley floors are adapted to this type of flash flood but that flows of such force and magnitude need to be allowed for in management in such an environment.

  14. Optical data processing and projected applications of the ERTS-1 imagery covering the 1973 Mississippi River Valley floods

    USGS Publications Warehouse

    Deutsch, Morris; Ruggles, Fred

    1974-01-01

    Flooding along the Mississippi River and some of its tributaries was detected by the multispectral scanner (MSS) on the Earth Resources Technology Satellite (ERTS-1) on at least three orbits during the spring of 1973. The ERTS data provided the first opportunity for mapping the regional extent of flooding at the time of the imagery. Special optical data processing techniques were used to produce a variety of multispectral color composites enhancing flood-plain details. One of these, a 2-color composite of near infrared bands 6 and 7, was enlarged and registered to 1:250,000-scale topographic maps and used as the basis for preparation of flood image maps. Two specially filtered 3-color composites of MSS bands 5, 6, and 7 and 4, 5, and 7 were prepared to aid in the interpretation of the data. The extent of the flooding was vividly depicted on a single image by 2-color temporal composites produced on the additive-color viewer using band 7 flood data superimposed on pre-flood band 7 images. On May 24, when the floodwaters at St. Louis receded to bankfull stage, imagery was again obtained by ERTS. Analysis of temporal data composites of the pre-flood and post-flood band 7 images indicate that changes in surface reflectance characteristics caused by the flooding can be delineated, thus making it possible to map the overall area flooded without the necessity of a real-time system to track and image the peak flood waves. Regional planning and disaster relief agencies such as the Corps of Engineers, Office of Emergency Preparedness, Soil Conservation Service, interstate river basin commissions and state agencies, as well as private lending and insurance institutions, have indicated strong potential applications for ERTS image-maps of flood-prone areas.

  15. A FRAMEWORK TO DESIGN AND OPTIMIZE CHEMICAL FLOODING PROCESSES

    SciTech Connect

    Mojdeh Delshad; Gary A. Pope; Kamy Sepehrnoori

    2005-07-01

    The goal of this proposed research is to provide an efficient and user friendly simulation framework for screening and optimizing chemical/microbial enhanced oil recovery processes. The framework will include (1) a user friendly interface to identify the variables that have the most impact on oil recovery using the concept of experimental design and response surface maps, (2) UTCHEM reservoir simulator to perform the numerical simulations, and (3) an economic model that automatically imports the simulation production data to evaluate the profitability of a particular design. Such a reservoir simulation framework is not currently available to the oil industry. The objectives of Task 1 are to develop three primary modules representing reservoir, chemical, and well data. The modules will be interfaced with an already available experimental design model. The objective of the Task 2 is to incorporate UTCHEM reservoir simulator and the modules with the strategic variables and developing the response surface maps to identify the significant variables from each module. The objective of the Task 3 is to develop the economic model designed specifically for the chemical processes targeted in this proposal and interface the economic model with UTCHEM production output. Task 4 is on the validation of the framework and performing simulations of oil reservoirs to screen, design and optimize the chemical processes.

  16. A FRAMEWORK TO DESIGN AND OPTIMIZE CHEMICAL FLOODING PROCESSES

    SciTech Connect

    Mojdeh Delshad; Gary A. Pope; Kamy Sepehrnoori

    2004-11-01

    The goal of this proposed research is to provide an efficient and user friendly simulation framework for screening and optimizing chemical/microbial enhanced oil recovery processes. The framework will include (1) a user friendly interface to identify the variables that have the most impact on oil recovery using the concept of experimental design and response surface maps, (2) UTCHEM reservoir simulator to perform the numerical simulations, and (3) an economic model that automatically imports the simulation production data to evaluate the profitability of a particular design. Such a reservoir simulation framework is not currently available to the oil industry. The objectives of Task 1 are to develop three primary modules representing reservoir, chemical, and well data. The modules will be interfaced with an already available experimental design model. The objective of the Task 2 is to incorporate UTCHEM reservoir simulator and the modules with the strategic variables and developing the response surface maps to identify the significant variables from each module. The objective of the Task 3 is to develop the economic model designed specifically for the chemical processes targeted in this proposal and interface the economic model with UTCHEM production output. Task 4 is on the validation of the framework and performing simulations of oil reservoirs to screen, design and optimize the chemical processes.

  17. A Framework to Design and Optimize Chemical Flooding Processes

    SciTech Connect

    Mojdeh Delshad; Gary A. Pope; Kamy Sepehrnoori

    2006-08-31

    The goal of this proposed research is to provide an efficient and user friendly simulation framework for screening and optimizing chemical/microbial enhanced oil recovery processes. The framework will include (1) a user friendly interface to identify the variables that have the most impact on oil recovery using the concept of experimental design and response surface maps, (2) UTCHEM reservoir simulator to perform the numerical simulations, and (3) an economic model that automatically imports the simulation production data to evaluate the profitability of a particular design. Such a reservoir simulation framework is not currently available to the oil industry. The objectives of Task 1 are to develop three primary modules representing reservoir, chemical, and well data. The modules will be interfaced with an already available experimental design model. The objective of the Task 2 is to incorporate UTCHEM reservoir simulator and the modules with the strategic variables and developing the response surface maps to identify the significant variables from each module. The objective of the Task 3 is to develop the economic model designed specifically for the chemical processes targeted in this proposal and interface the economic model with UTCHEM production output. Task 4 is on the validation of the framework and performing simulations of oil reservoirs to screen, design and optimize the chemical processes.

  18. Flood risk mitigation through natural flood management: reducing uncertainty through process studies at the local catchment scale

    NASA Astrophysics Data System (ADS)

    Wilkinson, M. E.; Quinn, P. F.; Nicholson, A.; O'Donnell, G. M.

    2012-04-01

    Intense farming has the potential to increase runoff rates. Therefore, there is great potential for managing land use to play a role in local scale strategies for managing flood risk. The European Floods Directive has created a platform for the management of flood risk. Natural flood management measures have a role in the implementation of the directive. One type of such natural flood management measures are Runoff Attenuation Features (RAFs). RAFs are cost effective soft engineered features used for slowing and storing water at the source during flood events. For the optimal use of such features, there is a need to ascertain how they operate across a range of flood events of varying return periods. Based on local scale knowledge and understanding, runoff flow pathways are identified, managed and runoff is tackled at the source. The Belford catchment, UK (5.7km2), is an example of a catchment whereby a range of RAF measures have been implemented to help reduce flood risk. Hydrological data from an extensive nested monitoring network have been collected over a four-year period. Over this period numerous RAFs were installed throughout the catchment and their effectiveness was tested against a large number of storm events. There are currently 30 RAFs in the catchment storing ~15,000m3. Qualitatively, evidence from the RAFs has showed that the features are functioning correctly during large events. They are slowing and storing runoff, and disconnecting fast flow pathways that are contributing to the flood hydrograph. There is also emerging evidence that suggests that the travel time of the peak is also being delayed. However, there is a large degree of uncertainty quantifying the degree in which the features are attenuating the flow, owing to natural variability in the short dataset. There is a need for data driven models based on field evidence to reduce the uncertainty. Quantitative analysis of the impact the RAFs have on reducing and delaying the peak discharge

  19. Floods and Flash Flooding

    MedlinePlus

    Floods and flash flooding Now is the time to determine your area’s flood risk. If you are not sure whether you ... If you are in a floodplain, consider buying flood insurance. Do not drive around barricades. If your ...

  20. Coupling glacial lake impact, dam breach, and flood processes: A modeling perspective

    NASA Astrophysics Data System (ADS)

    Worni, Raphael; Huggel, Christian; Clague, John J.; Schaub, Yvonne; Stoffel, Markus

    2014-11-01

    Glacial lake outburst floods (GLOFs) are highly mobile mixtures of water and sediment that occur suddenly and are capable of traveling tens to hundreds of kilometers with peak discharges and volumes several orders of magnitude larger than those of normal floods. They travel along existing river channels, in some instances into populated downstream regions, and thus pose a risk to people and infrastructure. Many recent events involve process chains, such as mass movements impacting glacial lakes and triggering dam breaches with subsequent outburst floods. A concern is that effects of climate change and associated increased instability of high mountain slopes may exacerbate such process chains and associated extreme flows. Modeling tools can be used to assess the hazard of potential future GLOFs, and process modeling can provide insights into complex processes that are difficult to observe in nature. A number of numerical models have been developed and applied to simulate different types of extreme flows, but such modeling faces challenges stemming from a lack of process understanding and difficulties in measuring extreme flows for calibration purposes. Here we review the state of knowledge of key aspects of modeling GLOFs, with a focus on process cascades. Analysis and simulation of the onset, propagation, and potential impact of GLOFs are based on illustrative case studies. Numerical models are presently available for simulating impact waves in lakes, dam failures, and flow propagation but have been used only to a limited extent for integrated simulations of process cascades. We present a spectrum of case studies from Patagonia, the European Alps, central Asia, and the Himalayas in which we simulate single processes and process chains of past and potential future events. We conclude that process understanding and process chain modeling need to be strengthened and that research efforts should focus on a more integrative treatment of processes in numerical models.

  1. State-of-the-art review of nitrogen and flue gas flooding in enhanced oil recovery. Final report

    SciTech Connect

    Anada, H.R.

    1980-12-01

    This report provides a review of technical publications and patents in the field of nitrogen and flue gas flooding in Enhanced Oil Recovery (EOR). The physical and chemical characteristics of nitrogen and flue gas are provided with some comparisons with CO/sub 2/ related to EOR operations. Experimental research and field based activities using nitrogen and flue gas are briefly summarized. Cost data for generation of nitrogen and flue gases are provided. Nitrogen and flue gas costs are approximately one third to one half that of CO/sub 2/. The low cost of production and its non-corrosive nature are advantages of using nitrogen, whereas the higher miscibility pressure requirement is a disadvantage. Nitrogen flooding does not work well with low API gravity crudes. Miscible displacement with nitrogen seems promising for oils containing solution gas. Flue gas flooding can be applied to low API gravity crude reservoirs. However, flue gas flooding creates operating problems due to its corrosive nature. The report provides a discussion on process and reservoir parameters that affect nitrogen and/or flue gas flooding in EOR. A bibliography of related literature is provided in the appendices.

  2. Linkages between flood, aquatic organic matter, and food web processes in the Okavango Delta, Botswana

    NASA Astrophysics Data System (ADS)

    Mladenov, N.; Murray-Hudson, M.; Mosepele, K.; Lindholm, M.

    2004-12-01

    The Okavango Delta of Botswana is a pristine but threatened wetland that ranges in size from 15,000 - 28,000 km2. Previous research has shown that an annual flooding event exerts controls on the quantity and chemical quality of aquatic organic matter (OM) at the Delta scale. In permanently-inundated areas, the perennial water supply maintains low dissolved organic carbon (DOC) concentrations and more microbial sources of OM, as evidenced by low specific UV absorbance and high fluorescence index values. In seasonally-inundated areas, the annual flood causes a pulse of DOC (over 5 mg C/L) and a shift to vegetation-derived DOC, as a result of the inundation of vegetation and soils. Because seasonal floodplains, which encompass 10,000 - 12,000 km2 of the Okavango Delta, become productive grazing areas after the flood and because a dominant portion of fish biomass production takes place in seasonal floodplains, the productivity of these areas is significant for higher trophic levels. Planned water developments upstream of the Delta may shorten/flatten the hydrological pulse and impact the transport and mobilization of organic matter within the Delta. The impacts of reduced flows on extent and duration of flooding have been examined. However, the secondary effects on biological productivity have received less attention. We hypothesize that varying sources of OM, controlled by the hydrologic regime of the Delta, and OM transformations from bacterial and UV degradation exert an influence on floodplain productivity. This study presents results of leaching and photodegradation experiments and observations of changes in algal populations and floodplain standing stock to demonstrate important linkages between biological, ecological, and hydrological processes in the Okavango Delta. Our results support that the DOC that is mobilized by the flood supports heterotrophic microbial populations which, in turn, support the biological productivity of seasonal floodplains.

  3. 4-D High-Resolution Seismic Reflection Monitoring of Miscible CO2 Injected into a Carbonate Reservoir

    SciTech Connect

    Richard D. Miller; Abdelmoneam E. Raef; Alan P. Byrnes; William E. Harrison

    2005-09-01

    The objective of this research project is to acquire, process, and interpret multiple high-resolution 3-D compressional wave and 2-D, 2-C shear wave seismic data to observe changes in fluid characteristics in an oil field before, during, and after the miscible carbon dioxide (CO{sub 2}) flood that began around December 1, 2003, as part of the DOE-sponsored Class Revisit Project (DOE DE-AC26-00BC15124). Unique and key to this imaging activity is the high-resolution nature of the seismic data, minimal deployment design, and the temporal sampling throughout the flood. The 900-m-deep test reservoir is located in central Kansas oomoldic limestones of the Lansing-Kansas City Group, deposited on a shallow marine shelf in Pennsylvanian time. After 18 months of seismic monitoring, one baseline and six monitor surveys clearly imaged changes that appear consistent with movement of CO{sub 2} as modeled with fluid simulators.

  4. 4-D High-Resolution Seismic Reflection Monitoring of Miscible CO2 Injected into a Carbonate Reservoir

    SciTech Connect

    Richard D. Miller; Abdelmoneam E. Raef; Alan P. Byrnes; William E. Harrison

    2007-06-30

    The objective of this research project was to acquire, process, and interpret multiple high-resolution 3-D compressional wave and 2-D, 2-C shear wave seismic data in the hopes of observing changes in fluid characteristics in an oil field before, during, and after the miscible carbon dioxide (CO{sub 2}) flood that began around December 1, 2003, as part of the DOE-sponsored Class Revisit Project (DOE No.DE-AC26-00BC15124). Unique and key to this imaging activity is the high-resolution nature of the seismic data, minimal deployment design, and the temporal sampling throughout the flood. The 900-m-deep test reservoir is located in central Kansas oomoldic limestones of the Lansing-Kansas City Group, deposited on a shallow marine shelf in Pennsylvanian time. After 30 months of seismic monitoring, one baseline and eight monitor surveys clearly detected changes that appear consistent with movement of CO{sub 2} as modeled with fluid simulators and observed in production data. Attribute analysis was a very useful tool in enhancing changes in seismic character present, but difficult to interpret on time amplitude slices. Lessons learned from and tools/techniques developed during this project will allow high-resolution seismic imaging to be routinely applied to many CO{sub 2} injection programs in a large percentage of shallow carbonate oil fields in the midcontinent.

  5. 4-D High-Resolution Seismic Reflection Monitoring of Miscible CO2 Injected into a Carbonate Reservoir

    SciTech Connect

    Richard D. Miller; Abdelmoneam E. Raef; Alan P. Byrnes; William E. Harrison

    2006-08-31

    The objective of this research project is to acquire, process, and interpret multiple high-resolution 3-D compressional wave and 2-D, 2-C shear wave seismic data in an attempt to observe changes in fluid characteristics in an oil field before, during, and after the miscible carbon dioxide (CO{sub 2}) flood that began around December 1, 2003, as part of the DOE-sponsored Class Revisit Project (DOE DE-AC26-00BC15124). Unique and key to this imaging activity is the high-resolution nature of the seismic data, minimal deployment design, and the temporal sampling throughout the flood. The 900-m-deep test reservoir is located in central Kansas oomoldic limestones of the Lansing-Kansas City Group, deposited on a shallow marine shelf in Pennsylvanian time. After 30 months of seismic monitoring, one baseline and eight monitor surveys clearly detected changes that appear consistent with movement of CO{sub 2} as modeled with fluid simulators and observed in production data.

  6. How do storage and drainage processes influence extreme floods in the Swiss Alps?

    NASA Astrophysics Data System (ADS)

    Smoorenburg, Maarten; Volze, Nina; Margreth, Michael; Scherrer, Simon; Naef, Felix

    2013-04-01

    Comparison of extreme flood runoff hydrographs in steep mountainous catchments in the Swiss Alps reveals large differences in the capability of catchments to dampen runoff formation. In some catchments a dampened runoff response is observed with a threshold-like reaction to very extreme rainfall inputs, whereas in other catchments this threshold-like behavior is already observed during much smaller storms, or has not been observed at all. The threshold-like behavior makes estimation of flood risks with long return periods highly uncertain. Therefore, understanding of dampening mechanisms is key to assessing catchment vulnerability to extreme events. We present typical flood responses in various mountainous catchments and try to explain what types of geomorphological features have enough storage potential to cause the observed dampening of the runoff formation. The dampened reaction at the catchment scale results from the spatial distribution of these geomorphological features in the landscape and how water is stored and drained. For better understanding of the storage and drainage processes and timescales, we have measured runoff in springs and headwater catchments dominated by geomorphological features with large storage potential, such as talus slopes, moraines and deep-seated creeping landmasses. Additional insights were obtained from a large scale sprinkling experiment on a creeping landmass slope (135 m2) and groundwater observations in its fissured-rock subsurface. The measurements show how these geomorphological features, even in steep terrain, may hold water long enough to cause a dampened flood response. To transfer these insights to the catchment scale, a mapping scheme was developed to delineate the areas with large storage potential and rank their drainage intensity. The mapping scheme benefits much from combing new data sources like high resolution digital elevation models (2 m by 2 m), aerial photographs and detailed geo(morpho)logical maps. The

  7. Concentration-dependent diffusion instability in reactive miscible fluids.

    PubMed

    Bratsun, Dmitry; Kostarev, Konstantin; Mizev, Aleksey; Mosheva, Elena

    2015-07-01

    We report on chemoconvective pattern formation phenomena observed in a two-layer system of miscible fluids filling a vertical Hele-Shaw cell. We show both experimentally and theoretically that the concentration-dependent diffusion coupled with frontal acid-base neutralization can give rise to the formation of a local unstable zone low in density, resulting in a perfectly regular cell-type convective pattern. The described effect gives an example of yet another powerful mechanism which allows the reaction-diffusion processes to govern the flow of reacting fluids under gravity conditions. PMID:26274115

  8. Impact of the 2013 summer flood on hydrological processes and sediment transport in Lake Mondsee and its catchment (Austria)

    NASA Astrophysics Data System (ADS)

    Mueller, P.; Kaempf, L.; Guntner, A.; Brauer, A.; Merz, B.

    2013-12-01

    One crucial limitation in the field of flood frequency analysis is the availability of long instrumental flood time series. Geoarchives such as lake sediments record land surface processes including extreme events and are used to elongate instrumental time series to geological time scales. A seasonally resolved flood layer chronology over the past 7000 years has already been established from varved lake sediments of Lake Mondsee (Upper Austria). The interpretation of lacustrine flood layer chronologies, however, requires detailed understanding of hydro-sedimentary processes during floods, including the transformation of the rain event into discharge and sediment dynamics from the catchment's source areas until the deposition within the lake. For this purpose, flood and sediment transport related variables like precipitation, runoff and suspended sediment concentration are monitored at five gauges in the Fuschler Ache river catchment, the largest sub-catchment draining to Lake Mondsee. These gauges cover the catchment from the headwaters to the outlet into Lake Mondsee. Lake monitoring is realized by implementing four buoys and two multi-level sediment traps. Meteorological and limno-physical variables measured at each buoy with 15 minute resolution are turbidity as surrogate for suspended sediment concentration, water temperature and flow velocity in different water depths as well as wind, air temperature and relative humidity. The monitoring system provided a unique data set for the extreme summer flood in June 2013. The data show the stream response to an extreme rainfall event, processes and rates of sediment transport in the catchment and sediment dynamics and sedimentation rates within the lake. A comparison of the 2013 summer event to past severe flood events in the Lake Mondsee catchment elucidates the need of detailed process understanding of the catchment processes and the lake-internal processes to properly interpret flood chronologies derived from

  9. A review of atmospheric and land surface processes with emphasis on flood generation in the Southern Himalayan rivers.

    PubMed

    Dimri, A P; Thayyen, R J; Kibler, K; Stanton, A; Jain, S K; Tullos, D; Singh, V P

    2016-06-15

    Floods in the southern rim of the Indian Himalayas are a major cause of loss of life, property, crops, infrastructure, etc. They have long term socio-economic impacts on the habitat living along/across the Himalayas. In the recent decade extreme precipitation events have led to numerous flash floods in and around the Himalayan region. Sporadic case-based studies have tried to explain the mechanisms causing the floods. However, in some of the cases, the causative mechanisms have been elusive. Various types of flood events have been debated at different spatial and temporal scales. The present study provides an overview of mechanisms that lead to floods in and around the southern rim of the Indian Himalayas. Atmospheric processes, landuse interaction, and glacier-related outbreaks are considered in the overview. PMID:26974566

  10. Using phase diagrams to predict the performance of cosolvent floods for NAPL remediation

    SciTech Connect

    Falta, R.W.

    1998-12-31

    Cosolvent flooding using water miscible solvents such as alcohols has been proposed as an in situ NAPL remediation technique. This process is conceptually similar to enhanced oil recovery (EOR) using alcohols and some surfactant formulations. As a result of interest in the EOR aspects of these systems, analytical and graphical methods based on fractional flow theory were developed in the petroleum engineering literature for modeling these floods. The existing fractional flow solutions have not been used previously in environmental applications of cosolvent flooding, but they are applicable and provide many useful insights into the process. These applications are discussed, with an emphasis on explaining the mechanisms which tend to mobilize trapped NAPL during a cosolvent flood. The theory provides a simple way to predict the general behavior of a cosolvent flood using the phase diagram. It is concluded that the one-dimensional performance of a cosolvent flood can be predicted largely by inspection of the ternary phase diagram. In particular, the nature of the cosolvent flood depends primarily on the position of the cosolvent injection concentration relative to a critical tie line extension which passes through the plait point, tangent to the binodal curve.

  11. Spatial Analysis in Determination Of Flood Prone Areas Using Geographic Information System and Analytical Hierarchy Process at Sungai Sembrong's Catchment

    NASA Astrophysics Data System (ADS)

    Bukari, S. M.; Ahmad, M. A.; Wai, T. L.; Kaamin, M.; Alimin, N.

    2016-07-01

    Floods that struck Johor state in 2006 and 2007 and the East Coastal in 2014 have triggered a greatly impact to the flood management here in Malaysia. Accordingly, this study conducted to determine potential areas of flooding, especially in Batu Pahat district since it faces terrifying experienced with heavy flood. This objective is archived by using the application of Geographic Information Systems (GIS) on study area of flood risk location at the watershed area of Sungai Sembrong. GIS functions as spatial analysis is capable to produce new information based on analysis of data stored in the system. Meanwhile the Analytical Hierarchy Process (AHP) was used as a method for setting up in decision making concerning the existing data. By using AHP method, preparation and position of the criteria and parameters required in GIS are neater and easier to analyze. Through this study, a flood prone area in the watershed of Sungai Sembrong was identified with the help of GIS and AHP. Analysis was conducted to test two different cell sizes, which are 30 and 5. The analysis of flood prone areas were tested on both cell sizes with two different water levels and the results of the analysis were displayed by GIS. Therefore, the use of AHP and GIS are effective and able to determine the potential flood plain areas in the watershed area of Sungai Sembrong.

  12. Viscous fingering with partially miscible fluids

    NASA Astrophysics Data System (ADS)

    Fu, X.; Cueto-Felgueroso, L.; Juanes, R.

    2015-12-01

    When a less viscous fluid displaces a more viscous fluid, the contrast in viscosity destabilizes the interface between the two fluids, leading to the formation of fingers. Experimental and numerical studies of viscous fingering have focused on fluids that are either fully miscible (e.g. water and glycerol) or perfectly immiscible (e.g. water and oil). In practice, however, the miscibility of two fluids can change appreciably with temperature and pressure, and often falls into the case of partial miscibility, where two fluids have limited solubility in each other (e.g. CO2 and water). Following our recent work for miscible systems (Jha et al., PRL 2011, 2013) and immiscible systems (Cueto-Felgueroso and Juanes, PRL 2012, JFM 2014), here we propose a phase-field model for fluid-fluid displacements in a porous medium, when the two fluids have limited (but nonzero) solubility in one another. In our model, partial miscibility is characterized through the design of the thermodynamic free energy of the two-fluid system. We express the model in dimensionless form and elucidate the key dimensionless groups that control the behavior of the system. We present high-resolution numerical simulations of the model applied to the viscous fingering problem. On one hand, we demonstrate the effect of partial miscibility on the hydrodynamic instability. On the other, we elucidate the role of the degree of fingering on the rate of mutual fluid dissolution. Figure caption: final snapshots in simulations of viscous fingering with a two-fluid system mimicking that of CO2 and water. The colormap corresponds to the concentration of CO2. A band of less viscous gas phase rich in CO2 (red) displaces through the more viscous liquid phase that is undersaturated with CO2 (blue). At the fluid interface, an exchange of CO2 occurs as a result of local chemical potentials that drives the system towards thermodynamic equilibrium. This results in a shrinkage of gas phase as well as a local increase in

  13. Influence of seismic processes and volcanic activity on the formation of disastrous floods

    NASA Astrophysics Data System (ADS)

    Trifonov, Dmitriy

    2014-05-01

    Traditionally, the main cause of catastrophic floods are considered prolonged heavy rains, which lead to over-saturation of soil moisture and the deposition of precipitation on the surface of the earth. And at the same time there is reason to believe that precipitation cannot be the main cause of floods. Firstly, we observe a catastrophic floods not in every case of heavy precipitation: moreover, a direct correlation between precipitation intensity and scale of the flooding is not detected. Secondly, a simple calculation shows that the quantity of water, that drops down to the ground with torrential rains, are insufficient to cover the earth's surface such layer of water, where we can talk about the flood (especially catastrophic). In particular, the intensity of normal not tropical rainfall does not exceed 60 mm per hour. Then such a downpour would have to go continuously for at least two days in a row, to cause flooding of a height of 3 m provided a complete impenetrability of the earth's surface. In reality, however, such showers last no more than half an hour. Thus, it can be argued that the source of water for catastrophic floods fed by ground water, the volume of which is comparable with the volume of all surface water on Earth [1]. Classic examples of surface and groundwater interactions are, on the one hand, springs and artesian wells, and on the other hand, the phenomenon of absorption of precipitation by soil. In normal conditions underground water is moving by aquifers, penetrating through the pores and cracks in rocks in the conditions of nonstationary/unsteady filtration, forming a 3D network of underground channels in different directions (horizontal, vertical, inclined), including the so-called underground lakes - water basins in underground cavities. Especially strongly these processes are shown in the fractured and karst rocks. It is also important that the movement of water obeys the laws of hydrostatics and hydrodynamics in terms of specific

  14. Molecular order, miscibility, and rheology of molten polyethylenes

    NASA Astrophysics Data System (ADS)

    Hussein, Ibnelwaleed Ali

    of LLDPE and LDPE is discussed. Partial miscibility is observed in blends mixed at a temperature below 208°C, whereas blends mixed above that temperature were almost immiscible. Increasing the branch length of the LLDPE from butene to octene increased miscibility slightly. Literature reporting polyethylene melt behavior is critically reviewed over the last four decades and found to contain many anomalies of molecular order and structural transformations. The scientific community and the polyethylene processing industry need to investigate the implications of these findings.

  15. Wetting induced instabilities in miscible polymer blends

    NASA Astrophysics Data System (ADS)

    Clarke, Nigel; Thomas, Katherine; Steiner, Ullrich; Poetes, Rosa; Morariu, Mihai

    2011-03-01

    The behaviour of miscible blends of polystyrene (PS)/poly(vinyl methyl ether)(PVME) of varying compositions has been investigated at temperatures where PS and PVME are miscible. The PVME is seen to enrich the polymer-air surface, forming a layer with a width that is comparable to the correlation length. Further heating close to the demixing temperature results in the formation of a capillary instabilities at the polymer surface exhibiting a spinodal-like pattern with a characteristic wavelength that depends on the blend composition. Formation of these instabilities is seen for all blend compositions. We propose that these wetting induced instabilities result from coupled height and composition fluctuations in the PVME enriched surface layer, driving the build-up of long wavelength fluctuations.

  16. Dynamics of miscible displacements in round tubes

    SciTech Connect

    Meiburg, E.; Maxworthy, T.; Chen, C.Y.; Petitjeans, P.

    1995-12-31

    A combined experimental and numerical investigation of miscible two-phase flow in a capillary tube is reported. The fraction of fluid left behind on the wall is obtained as a function of the Peclet, Atwood, and Froude numbers. Scaling arguments are presented for two distinct flow regimes, dominated by diffusion and convection, respectively. In the latter one, an effective surface tension value can be estimated.

  17. Molecular Driving Forces behind the Tetrahydrofuran-Water Miscibility Gap.

    PubMed

    Smith, Micholas Dean; Mostofian, Barmak; Petridis, Loukas; Cheng, Xiaolin; Smith, Jeremy C

    2016-02-01

    The tetrahydrofuran-water binary system exhibits an unusual closed-loop miscibility gap (transitions from a miscible regime to an immiscible regime back to another miscible regime as the temperature increases). Here, using all-atom molecular dynamics simulations, we probe the structural and dynamical behavior of the binary system in the temperature regime of this gap at four different mass ratios, and we compare the behavior of bulk water and tetrahydrofuran. The changes in structure and dynamics observed in the simulations indicate that the temperature region associated with the miscibility gap is distinctive. Within the miscibility-gap temperature region, the self-diffusion of water is significantly altered and the second virial coefficients (pair-interaction strengths) show parabolic-like behavior. Overall, the results suggest that the gap is the result of differing trends with temperature of minor structural changes, which produces interaction virials with parabolic temperature dependence near the miscibility gap. PMID:26734991

  18. Flood hazards analysis based on changes of hydrodynamic processes in fluvial systems of Sao Paulo, Brazil.

    NASA Astrophysics Data System (ADS)

    Simas, Iury; Rodrigues, Cleide

    2016-04-01

    The metropolis of Sao Paulo, with its 7940 Km² and over 20 million inhabitants, is increasingly being consolidated with disregard for the dynamics of its fluvial systems and natural limitations imposed by fluvial terraces, floodplains and slopes. Events such as floods and flash floods became particularly persistent mainly in socially and environmentally vulnerable areas. The Aricanduva River basin was selected as the ideal area for the development of the flood hazard analysis since it presents the main geological and geomorphological features found in the urban site. According to studies carried out by Anthropic Geomorphology approach in São Paulo, to study this phenomenon is necessary to take into account the original hydromorphological systems and its functional conditions, as well as in which dimensions the Anthropic factor changes the balance between the main variables of surface processes. Considering those principles, an alternative model of geographical data was proposed and enabled to identify the role of different driving forces in terms of spatial conditioning of certain flood events. Spatial relationships between different variables, such as anthropogenic and original morphology, were analyzed for that purpose in addition to climate data. The surface hydrodynamic tendency spatial model conceived for this study takes as key variables: 1- The land use present at the observed date combined with the predominant lithological group, represented by a value ranging 0-100, based on indexes of the National Soil Conservation Service (NSCS-USA) and the Hydraulic Technology Center Foundation (FCTH-Brazil) to determine the resulting balance of runoff/infiltration. 2- The original slope, applying thresholds from which it's possible to determine greater tendency for runoff (in percents). 3- The minimal features of relief, combining the curvature of surface in plant and profile. Those three key variables were combined in a Geographic Information System in a series of

  19. Optical data processing and projected applications of the ERTS-1 imagery covering the 1973 Mississippi River Valley floods

    NASA Technical Reports Server (NTRS)

    Deutsch, M.; Ruggles, F.

    1977-01-01

    Flooding was detected along the Mississippi River and some of its tributaries by the multispectral scanner (MSS) on the ERTS-1 on at least three orbits during the spring of 1973. The ERTS data provided the first opportunity for mapping the regional extent of flooding. Special optical data processing techniques were used to produce a variety of multispectral color composites enhancing flood-plain details. One of these, a 2-color composite of near infrared bands 6 and 7, was enlarged and registered to 1:250,000-scale topographic maps and used as the basis for preparation of flood image maps. Two specifically filtered 3-color composites of MSS bands 5,6, and 7 and 4, 5, and 7 were prepared.

  20. DEVELOPMENT OF MORE-EFFICIENT GAS FLOODING APPLICABLE TO SHALLOW RESERVOIRS

    SciTech Connect

    William R. Rossen; Russell T. Johns; Gary A. Pope

    2003-08-21

    The objective of this research is to widen the applicability of gas flooding to shallow oil reservoirs by reducing the pressure required for miscibility using gas enrichment and increasing sweep efficiency with foam. Task 1 examines the potential for improved oil recovery with enriched gases. Subtask 1.1 examines the effect of dispersion processes on oil recovery and the extent of enrichment needed in the presence of dispersion. Subtask 1.2 develops a fast, efficient method to predict the extent of enrichment needed for crude oils at a given pressure. Task 2 develops improved foam processes to increase sweep efficiency in gas flooding. Subtask 2.1 comprises mechanistic experimental studies of foams with N2 gas. Subtask 2.2 conducts experiments with CO{sub 2} foam. Subtask 2.3 develops and applies a simulator for foam processes in field application.

  1. Inland Flood Hazards

    NASA Astrophysics Data System (ADS)

    Wohl, Ellen E.

    2000-07-01

    A comprehensive, interdisciplinary review of issues related to inland flood hazards, this important work addresses physical controls on flooding, flood processes and effects, and responses to flooding, from the perspectives of human, aquatic, and riparian communities. The contributors, recognized experts in their fields, draw on examples and case studies of inland flood hazards from around the world. The volume is unique in that it addresses how the nonoccurrence of floods, in association with flow regulation and other human manipulation of river systems, may create hazards for aquatic and riparian communities. This book will be a valuable resource for all professionals concerned with inland flood hazards.

  2. Investigations on transparent liquid-miscibility gap systems

    NASA Technical Reports Server (NTRS)

    Lacy, L. L.; Nishioka, G.; Ross, S.

    1979-01-01

    Sedimentation and phase separation is a well known occurrence in monotectic or miscibility gap alloys. Previous investigations indicate that it may be possible to prepare such alloys in a low-gravity space environment but recent experiments indicate that there may be nongravity dependent phase separation processes which can hinder the formation of such alloys. Such phase separation processes are studied using transparent liquid systems and holography. By reconstructing holograms into a commercial-particle-analysis system, real time computer analysis can be performed on emulsions with diameters in the range of 5 micrometers or greater. Thus dynamic effects associated with particle migration and coalescence can be studied. Characterization studies on two selected immiscible systems including an accurate determination of phase diagrams, surface and interfacial tension measurements, surface excess and wetting behavior near critical solution temperatures completed.

  3. Modeling a Glacial Lake Outburst Flood Process Chain: The Case of Lake Palcacocha and Huaraz, Peru

    NASA Astrophysics Data System (ADS)

    Chisolm, Rachel; Somos-Valenzuela, Marcelo; Rivas Gomez, Denny; McKinney, Daene C.; Portocarrero Rodriguez, Cesar

    2016-04-01

    One of the consequences of recent glacier recession in the Cordillera Blanca, Peru, is the risk of Glacial Lake Outburst Floods (GLOFs) from lakes that have formed at the base of retreating glaciers. GLOFs are often triggered by avalanches falling into glacial lakes, initiating a chain of processes that may culminate in significant inundation and destruction downstream. This paper presents simulations of all of the processes involved in a potential GLOF originating from Lake Palcacocha, the source of a previously catastrophic GLOF on December 13, 1941, 1800 people in the city of Huaraz, Peru. The chain of processes simulated here includes: (1) avalanches above the lake; (2) lake dynamics resulting from the avalanche impact, including wave generation, propagation, and run-up across lakes; (3) terminal moraine overtopping and dynamic moraine erosion simulations to determine the possibility of breaching; (4) flood propagation along downstream valleys; and (5) inundation of populated areas. The results of each process feed into simulations of subsequent processes in the chain, finally resulting in estimates of inundation in the city of Huaraz. The results of the inundation simulations were converted into flood intensity and hazard maps (based on an intensity-likelihood matrix) that may be useful for city planning and regulation. Three avalanche events with volumes ranging from 0.5-3 x 106 m3 were simulated, and two scenarios of 15 m and 30 m lake lowering were simulated to assess the potential of mitigating the hazard level in Huaraz. For all three avalanche events, three-dimensional hydrodynamic models show large waves generated in the lake from the impact resulting in overtopping of the damming-moraine. Despite very high discharge rates (up to 63.4 x 103 m3/s), the erosion from the overtopping wave did not result in failure of the damming-moraine when simulated with a hydro-morphodynamic model using excessively conservative soil characteristics that provide very

  4. Modeling a glacial lake outburst flood process chain: the case of Lake Palcacocha and Huaraz, Peru

    NASA Astrophysics Data System (ADS)

    Somos-Valenzuela, Marcelo A.; Chisolm, Rachel E.; Rivas, Denny S.; Portocarrero, Cesar; McKinney, Daene C.

    2016-07-01

    One of the consequences of recent glacier recession in the Cordillera Blanca, Peru, is the risk of glacial lake outburst floods (GLOFs) from lakes that have formed at the base of retreating glaciers. GLOFs are often triggered by avalanches falling into glacial lakes, initiating a chain of processes that may culminate in significant inundation and destruction downstream. This paper presents simulations of all of the processes involved in a potential GLOF originating from Lake Palcacocha, the source of a previously catastrophic GLOF on 13 December 1941, killing about 1800 people in the city of Huaraz, Peru. The chain of processes simulated here includes (1) avalanches above the lake; (2) lake dynamics resulting from the avalanche impact, including wave generation, propagation, and run-up across lakes; (3) terminal moraine overtopping and dynamic moraine erosion simulations to determine the possibility of breaching; (4) flood propagation along downstream valleys; and (5) inundation of populated areas. The results of each process feed into simulations of subsequent processes in the chain, finally resulting in estimates of inundation in the city of Huaraz. The results of the inundation simulations were converted into flood intensity and preliminary hazard maps (based on an intensity-likelihood matrix) that may be useful for city planning and regulation. Three avalanche events with volumes ranging from 0.5 to 3 × 106 m3 were simulated, and two scenarios of 15 and 30 m lake lowering were simulated to assess the potential of mitigating the hazard level in Huaraz. For all three avalanche events, three-dimensional hydrodynamic models show large waves generated in the lake from the impact resulting in overtopping of the damming moraine. Despite very high discharge rates (up to 63.4 × 103 m3 s-1), the erosion from the overtopping wave did not result in failure of the damming moraine when simulated with a hydro-morphodynamic model using excessively conservative soil

  5. Process-Based Modeling of Floods Through Shrub Carrs of Varying Densities

    NASA Astrophysics Data System (ADS)

    Smith, J.

    2001-12-01

    Floodplain surfaces typically are protected from erosion during deep overbank flows by vegetation of varying types and densities. Drag on stems, branches, leaves, and exposed roots of the floodplain plants reduces both the near-bed flow and the fluid forces on the sediment grains. The drag on vegetation and on topographic elements of the floodplain surface can be calculated by carefully applying fundamental fluid-mechanical principals. Doing so requires identification and appropriate approximation of the reference velocity in the drag equation, and accurate estimates of the floodplain plant geometries and spacings. For shrubs, calculations indicate that skin friction on leaves is negligible compared to form drag on stems and branches, whereas, for uncut grasses, skin friction on the fronds is of primary importance. Scaling relationships are developed for each shrub species for specific applications, so that the fluid mechanically important properties can be estimated from mean stem diameters, mean stem group diameters, and mean stem group spacings. Stem group spacings and diameters can be related to shrub-canopy spacings and diameters respectively, which are determined from aerial photographs in the applications. A process-based model incorporating the necessary principles was developed and applied to a headwater tributary of East Plum Creek, Colorado. Calculations using the estimated decrease in density of the sandbar willows along this tributary accurately postdict the site of initiation of floodplain unraveling (transformation from a narrow, sinuous stream to a wide, straight one) that occurred during an extreme flood in 1965. Details of this application are presented in an accompanying poster. The model then is applied to Clark Fork of the Columbia River in the Deer Lodge Valley, Montana. This meandering fluvial system is an EPA Superfund site, because the flood-of-record in 1908 deposited several decimeters of contaminated tailings in the meander belt. The

  6. Pore-Scale Study of Miscible Displacements in Porous Media Using Lattice Boltzmann Method

    NASA Astrophysics Data System (ADS)

    Zhang, Ting; Shi, Baochang; Huang, Changsheng; Liang, Hong

    2015-12-01

    In the past few years, the miscible displacements in porous media were usually simulated by some semiempirical models based on the volume averaging at the representative elementary volume scale. To better understand the microscopic mechanism of the viscous fingering phenomenon in porous media for miscible fluids, in this paper the miscible displacements processes in porous media are studied using the lattice Boltzmann method (LBM) at the pore scale. First, the code of LBM is tested by simulating the displacement process of two miscible fluids with the same viscosity between two parallel plates which is the well-known Taylor-Aris dispersion problem, and comparing the results with the theoretical predictions. Then, the effects of the Péclet number Pe, the viscosity ratio M and the structure of the porous media on the displacement phenomenon are investigated, and the location and velocity of the finger tip, the displacement efficiency are also studied. In this paper, the displacement efficiency is calculated by 1-m, here the quantity m is defined as m=V_M/V_T, where V_M is the volume of more viscous fluids (the displaced fluid) left behind the finger tip, V_T is the total pore volume behind the finger tip. It can be found that the "interface" of two fluids will become clearer with the increasing of the Péclet number. As Pe and M are large enough, the viscous fingering phenomenon will occur, and in the front of the finger, "mushroom-like" pattern can be observed. Besides, with the increasing of Pe or M the quantity m will be increased too, i.e., the displacement efficiency will be decreased. While Pe (or M) is greater than a certain value, the growth rate of the quantity m will slow down. The same trend was observed for the miscible displacement in capillary tubes or Hele-Shaw cells. Besides, changing the structure of the porous media makes the finger pattern different. The present simulation results provide a good understanding of the microscopic mechanism of the

  7. Floodnet: a telenetwork for acquisition, processing and dissemination of earth observation data for monitoring and emergency management of floods

    NASA Astrophysics Data System (ADS)

    Blyth, Ken

    1997-08-01

    The aim of FLOODNET is to provide a communications and data distribution facility specifically designed to meet the demanding temporal requirements of flood monitoring within the European Union (EU). Currently, remotely sensed data are not fully utilized for flood applications because potential users are not familiar with the procedure for acquiring the data and do not have a defined route for obtaining help in processing and interpreting the data. FLOODNET will identify the potential user groups within the EU and will, by demonstration, education and the use of telematics, increase the awareness of users to the capabilities of earth observation (EO) and the means by which they can acquire EO data. FLOODNET will act as a filter between users and satellite operation planners to help assign priorities for data acquisition against previously agreed criteria. The network will encourage a user community and will facilitate cross-sector information transfer, particularly between flood experts and administrative decision makers. The requirement for two levels of flood mapping is identified: (1) a rapid, broad-brush approach to assess the general flood situation and identify areas at greatest risk and in need of immediate assistance; (2) a detailed mapping approach, less critical in time, suitable for input to hydrological models or for flood risk evaluation. A likely networking technology is outlined, the basic functionality of a FLOODNET demonstrator is described and some of the economic benefits of the network are identified.

  8. Emerging Processes in Flood Regime Dynamics: Evidence from Spatiotemporal Statistics and a Nonlinear Dynamical Model of Coevolution.

    NASA Astrophysics Data System (ADS)

    Perdigão, Rui A. P.; Blöschl, Günter

    2015-04-01

    Emerging Processes in Flood Regime Dynamics are evaluated on the basis of symmetry breaks in the spatiotemporal sensitivity of flood regimes to changes in annual precipitation and a new dynamical model of flood regime change under nonlinearly interacting landscape-climate dynamics. The spatiotemporal sensitivity analysis is performed at regional scale using data from 804 catchments in Austria from 1976 to 2008. Results show that flood peaks change in a more responsive manner with spatial (regional) than with temporal (decadal) variability. Space-wise a 10% increase in precipitation leads to a 23% increase in flood peaks in Austria, whereas timewise a 10% increase in precipitation leads to an increase of just 6% in flood peaks. Looking at hydroclimatic regions in particular, catchments from stable dry lowlands and high wetlands exhibit similarity between the spatial and temporal flood responses to changes in precipitation (spatiotemporal symmetry) and low landscape-climate codependence. This suggests that these regions are not coevolving significantly. However, intermediate regions show differences between those responses (symmetry breaks) and higher landscape-climate codependence, suggesting undergoing coevolution. The break of symmetry is an emergent behaviour of the coupled system, stemming from the nonlinear interactions in the coevolving hydroclimate system. A dynamic coevolution index is then proposed relating spatiotemporal symmetry with relative characteristic celerities, which need to be taken into account in hydrological space-time trading. Coevolution is expressed here by the scale interaction between slow and fast dynamics, represented respectively by spatial and temporal characteristics. The diagnostic assessment of coevolution is complemented by a stylised nonlinear dynamical model of landscape-climate coevolution, in which landform evolution processes take place at the millennial scale (slow dynamics), and climate adjusts in years to decades (fast

  9. Mixing of two miscible fluids at high Schmidt number

    NASA Astrophysics Data System (ADS)

    Simmons, Mark; Alberini, Federico; Pain, Christopher; Matar, Omar

    2013-11-01

    The blending of two miscible liquids at high Schmidt number is an increasingly common industrial problem: as processes push towards shorter timescales yet the rheology of the fluids becomes increasingly complex. This leads to phenomena which resemble a quasi two-phase system with zero interfacial tension. In this study, we compare experimental results with computational fluid dynamics simulations using unstructured-mesh adaptivity for the flow of two Newtonian, or two power-law fluids through a complex geometry representative of a Kenics type static mixer used in industry. The geometry induces a stretching and folding of the fluid elements which causes exponential growth of the interface length down the geometry. The interfacial topology obtained from the simulations is compared with experiments carried out using Planar Laser Induced Fluorescence (PLIF), which enables the spatial distribution of each phase, and the interfaces between them, to be determined at the outlet of the geometry. EPSRC Programme Grant EP/K003976/1.

  10. Understanding processes that generate flash floods in the arid Judean Desert to the Dead Sea - a measurement network

    NASA Astrophysics Data System (ADS)

    Hennig, Hanna; Rödiger, Tino; Laronne, Jonathan B.; Geyer, Stefan; Merz, Ralf

    2016-04-01

    Flash floods in (semi-) arid regions are fascinating in their suddenness and can be harmful for humans, infrastructure, industry and tourism. Generated within minutes, an early warning system is essential. A hydrological model is required to quantify flash floods. Current models to predict flash floods are often based on simplified concepts and/or on concepts which were developed for humid regions. To more closely relate such models to local conditions, processes within catchments where flash floods occur require consideration. In this study we present a monitoring approach to decipher different flash flood generating processes in the ephemeral Wadi Arugot on the western side of the Dead Sea. To understand rainfall input a dense rain gauge network was installed. Locations of rain gauges were chosen based on land use, slope and soil cover. The spatiotemporal variation of rain intensity will also be available from radar backscatter. Level pressure sensors located at the outlet of major tributaries have been deployed to analyze in which part of the catchment water is generated. To identify the importance of soil moisture preconditions, two cosmic ray sensors have been deployed. At the outlet of the Arugot water is sampled and level is monitored. To more accurately determine water discharge, water velocity is measured using portable radar velocimetry. A first analysis of flash flood processes will be presented following the FLEX-Topo concept .(Savenije, 2010), where each landscape type is represented using an individual hydrological model according to the processes within the three hydrological response units: plateau, desert and outlet. References: Savenije, H. H. G.: HESS Opinions "Topography driven conceptual modelling (FLEX-Topo)", Hydrol. Earth Syst. Sci., 14, 2681-2692, doi:10.5194/hess-14-2681-2010, 2010.

  11. Oscillatory interfacial instability between miscible fluids

    NASA Astrophysics Data System (ADS)

    Shevtsova, Valentina; Gaponenko, Yuri; Mialdun, Aliaksandr; Torregrosa, Marita; Yasnou, Viktar

    Interfacial instabilities occurring between two fluids are of fundamental interest in fluid dynamics, biological systems and engineering applications such as liquid storage, solvent extraction, oil recovery and mixing. Horizontal vibrations applied to stratified layers of immiscible liquids may generate spatially periodic waving of the interface, stationary in the reference frame of the vibrated cell, referred to as a "frozen wave". We present experimental evidence that frozen wave instability exists between two ordinary miscible liquids of similar densities and viscosities. At the experiments and at the numerical model, two superimposed layers of ordinary liquids, water-alcohol of different concentrations, are placed in a closed cavity in a gravitationally stable configuration. The density and viscosity of these fluids are somewhat similar. Similar to the immiscible fluids this instability has a threshold. When the value of forcing is increased the amplitudes of perturbations grow continuously displaying a saw-tooth structure. The decrease of gravity drastically changes the structure of frozen waves.

  12. Design by Nature in a Confined Flood Alleviation Scheme: Analysis of Form-Process Feedbacks and Morphological Evolution

    NASA Astrophysics Data System (ADS)

    Hetherington, D.; German, S.

    2015-12-01

    AbstractMany conventional hard flood risk alleviation schemes have been detrimental to natural geomorphic processes and have damaged fluvial habitats. This is primarily due to the over-riding focus on managing flood risk by dictating channel capacity and hydraulics, which is not always conducive to the promotion of geomorphologically-healthy and diverse conditions that allow and promote natural processes. This paper explains how the principles of fluvial geomorphology had a large influence on the design, construction and post project monitoring of a flood alleviation scheme in Wales within a heavily confined river corridor that is designated as having special ecological status; without adversely impacting on flood risk. The challenge was to ensure that the physical habitat required by the important species (including Atlantic Salmon and Ranunculus) were retained and that the surrounding infrastructure and properties were not at risk of being undercut as a result of scour in the confined high energy channel. A geomorphologically-guided soft engineering approach was taken to promote local morphological diversity and flow diversity, utilising information from up and downstream natural river reaches, and general geomorphological principles. The proposed layout was modelled in 1D to understand the effects of the reprofiling on flows, allowing for a basic assessment of coarse sediment transport to be undertaken. A combination of terrestrial laser scanning and contact GPS surveys were used to monitor morphological evolution post construction, and to determine how morphological form adjusted post-construction within the confined channel. This paper will introduce the guiding principles of process restoration that influenced scheme design, and then report on the morphological evolution of the river channel that occurred as river processes produced and maintained a dynamic, diverse and healthy physical habitat. Keywords: Process Restoration; Form Process Feedbacks; Fluvial

  13. Grid infrastructure for automatic processing of SAR data for flood applications

    NASA Astrophysics Data System (ADS)

    Kussul, Natalia; Skakun, Serhiy; Shelestov, Andrii

    2010-05-01

    More and more geosciences applications are being put on to the Grids. Due to the complexity of geosciences applications that is caused by complex workflow, the use of computationally intensive environmental models, the need of management and integration of heterogeneous data sets, Grid offers solutions to tackle these problems. Many geosciences applications, especially those related to the disaster management and mitigations require the geospatial services to be delivered in proper time. For example, information on flooded areas should be provided to corresponding organizations (local authorities, civil protection agencies, UN agencies etc.) no more than in 24 h to be able to effectively allocate resources required to mitigate the disaster. Therefore, providing infrastructure and services that will enable automatic generation of products based on the integration of heterogeneous data represents the tasks of great importance. In this paper we present Grid infrastructure for automatic processing of synthetic-aperture radar (SAR) satellite images to derive flood products. In particular, we use SAR data acquired by ESA's ENVSAT satellite, and neural networks to derive flood extent. The data are provided in operational mode from ESA rolling archive (within ESA Category-1 grant). We developed a portal that is based on OpenLayers frameworks and provides access point to the developed services. Through the portal the user can define geographical region and search for the required data. Upon selection of data sets a workflow is automatically generated and executed on the resources of Grid infrastructure. For workflow execution and management we use Karajan language. The workflow of SAR data processing consists of the following steps: image calibration, image orthorectification, image processing with neural networks, topographic effects removal, geocoding and transformation to lat/long projection, and visualisation. These steps are executed by different software, and can be

  14. Miscible Applied Simulation Techniques for Energy Recovery

    Energy Science and Technology Software Center (ESTSC)

    2005-07-01

    During the use of MASTER at the New Mexico Petroleum Recovery Research Center (PRRC) as research division of New Mexico Institute of Mining and Technology a number of modification have been made to the original MASTER. We have worked at minimizing programming errors and incorporating a foaming option for surfactant solution (aqueous phase) injection altemating with gas (SAG) The original program checks and modifications performed at PRRC were under the direction of Dr. Shih-Hsien Changmore » under previous DOE contracts. The final modifications and completion of the documentation were performed by Dr. Zhengwen Zeng under DOE Contract Number DE-FG26-01BC15364. Drs. Chang and Zeng worked under Dr. Reid B. Grigg in the Gas Flooding Processes and Flow Heterogeneities Section of PRRC. This work is not intended to have any long-term support from the PRRC, but any errors should be reported to the Department of Energy for inclusion in future releases of MASTER. MASTER is an effective reservoir simulator for modeling a number of fluid flow problems and is a straight forward and economical program. We thank the Department of Energy for the original development of this program and the availability for our use.« less

  15. Process, mechanism and impacts of scale formation in alkaline flooding by a variable porosity and permeability model

    NASA Astrophysics Data System (ADS)

    Zhang, Zhen; Li, Jiachun

    2016-03-01

    In spite of the role of alkali in enhancing oil recovery (EOR), the formation of precipitation during alkaline-surfactant-polymer (ASP) flooding can severely do harm to the stratum of oil reservoirs, which has been observed in situ tests of oil fields such as scale deposits found in oil stratum and at the bottom of oil wells. On the other hand, remarkable variation of stratum parameters, e.g., pore radius, porosity, and permeability due to scale formation considerably affects seepage flow and alkaline flooding process in return. The objective of this study is to firstly examine these mutual influential phenomena and corresponding mechanisms along with EOR during alkaline flooding when the effects of precipitation are no longer negligible. The chemical kinetic theory is applied for the specific fundamental reactions to describe the process of rock dissolution in silica-based reservoirs. The solubility product principle is used to analyze the mechanism of alkali scale formation in flooding. Then a 3D alkaline flooding coupling model accounting for the variation of porosity and permeability is established to quantitatively estimate the impact of alkali scales on reservoir stratum. The reliability of the present model is verified in comparison with indoor experiments and field tests of the Daqing oil field. Then, the numerical simulations on a 1/4 well group in a 5-spot pattern show that the precipitation grows with alkali concentration, temperature, and injection pressure and, thus, reduces reservoir permeability and oil recovery correspondingly. As a result, the selection of alkali with a weak base is preferable in ASP flooding by tradeoff strategy.

  16. Process, mechanism and impacts of scale formation in alkaline flooding by a variable porosity and permeability model

    NASA Astrophysics Data System (ADS)

    Zhang, Zhen; Li, Jiachun

    2016-06-01

    In spite of the role of alkali in enhancing oil recovery (EOR), the formation of precipitation during alkaline-surfactant-polymer (ASP) flooding can severely do harm to the stratum of oil reservoirs, which has been observed in situ tests of oil fields such as scale deposits found in oil stratum and at the bottom of oil wells. On the other hand, remarkable variation of stratum parameters, e.g., pore radius, porosity, and permeability due to scale formation considerably affects seepage flow and alkaline flooding process in return. The objective of this study is to firstly examine these mutual influential phenomena and corresponding mechanisms along with EOR during alkaline flooding when the effects of precipitation are no longer negligible. The chemical kinetic theory is applied for the specific fundamental reactions to describe the process of rock dissolution in silica-based reservoirs. The solubility product principle is used to analyze the mechanism of alkali scale formation in flooding. Then a 3D alkaline flooding coupling model accounting for the variation of porosity and permeability is established to quantitatively estimate the impact of alkali scales on reservoir stratum. The reliability of the present model is verified in comparison with indoor experiments and field tests of the Daqing oil field. Then, the numerical simulations on a 1/4 well group in a 5-spot pattern show that the precipitation grows with alkali concentration, temperature, and injection pressure and, thus, reduces reservoir permeability and oil recovery correspondingly. As a result, the selection of alkali with a weak base is preferable in ASP flooding by tradeoff strategy.

  17. Improved Efficiency of Miscible C02 Floods and Enhanced Prospects for C02 Flooding Heterogeneous Reservoirs

    SciTech Connect

    David S. Schechter; Reid B. Grigg

    1998-07-07

    In this quarter, we used parallel isolated composite core to test the effectiveness of foam on oil recovery efficiency. This composite core differs from the previous core in two areas: 1) Pyrex® glass beads were used in the center region to form a high permeability region and 2) a fired Berea sandstone was used in the annulus region to form a low permeability region. We also started to conduct surfactant adsorption measurements on coreflooding substrates. Static measurements with three anionic surfactants were conducted on Pyrex® glass beads. Surfactant concentrations were determined to calculate the amount of surfactant adsorbed on the substrate. The preliminary results showed that the loss of surfactant due to adsorption at 500 ppm concentration were 0.34 mg/cm 3 , 0.29 mg/cm 3 , and 0.19 mg/cm 3 for surfactants Alipa®CD128, Chaser�CD1040 and Dowfax�8390, respectively. Simulations were performed to assess the applicability of horizontal wells as a tool to increase oil recovery in CO2 injection projects.

  18. Flow and sediment processes in a cutoff meander of the Danube Delta during episodic flooding

    NASA Astrophysics Data System (ADS)

    Jugaru Tiron, Laura; Le Coz, Jérôme; Provansal, Mireille; Panin, Nicolae; Raccasi, Guillaume; Dramais, Guillaume; Dussouillez, Philippe

    2009-05-01

    This article analyzes the water and suspended solid fluxes through a straightened meander of the southern branch of the Danube Delta (the St. George branch) during episodic flooding. The Mahmudia study site corresponds to a vast natural meander which was cut off in 1984-1988 by an artificial canal opened to shipping. The meander correction accelerated fluxes through the artificial canal and dramatically enhanced deposition in the former meander. After his formation, the cutoff meander acted as sediment storage locations, essentially removing channel and point bar sediments from the active sediment budget of the main channel. Increases in slope and stream power in reaches upstream and downstream have also occurred, but to a lesser degree. During the one-hundred-year recurrent flood in April 2006, bathymetry, flow velocity and discharge data were acquired across several sections of both natural and artificial channels with an acoustic Doppler current profiler (aDcp Workhorse Sentinel 600 kHz, Teledyne RDI) in order to investigate the distribution of the flow and sediment and his impact on sedimentation in a channelized reach and its adjacent cutoff. The contrasting hydro-sedimentary processes at work in both channels and bifurcation/confluence nodal points are analyzed from the measured flux distribution, morphological profiles and velocity and concentration patterns. In the cutoff, a diminishing of the intensity of the flow velocity (c. 50%) and of the SSC was observed correlated with the aggradation of the river bed. In the bifurcation/confluence nodal points and in the artificial canal were observed the most intensive hydrodynamic activity (high flow velocity, SSC concentration, degradation of the river bad). Both the event-scale and long-term morphological trends of the alluvial system are discussed analyzing the boundary shear stress and SSC variability. Excess boundary shear stress in the sub-reaches directly affected by cutoffs resulted in scour that increased

  19. "Physically-based" numerical experiment to determine the dominant hillslope processes during floods?

    NASA Astrophysics Data System (ADS)

    Gaume, Eric; Esclaffer, Thomas; Dangla, Patrick; Payrastre, Olivier

    2016-04-01

    To study the dynamics of hillslope responses during flood event, a fully coupled "physically-based" model for the combined numerical simulation of surface runoff and underground flows has been developed. A particular attention has been given to the selection of appropriate numerical schemes for the modelling of both processes and of their coupling. Surprisingly, the most difficult question to solve, from a numerical point of view, was not related to the coupling of two processes with contrasted kinetics such as surface and underground flows, but to the high gradient infiltration fronts appearing in soils, source of numerical diffusion, instabilities and sometimes divergence. The model being elaborated, it has been successfully tested against results of high quality experiments conducted on a laboratory sandy slope in the early eighties, which is still considered as a reference hillslope experimental setting (Abdul & Guilham). The model appeared able to accurately simulate the pore pressure distributions observed in this 1.5 meter deep and wide laboratory hillslope, as well as its outflow hydrograph shapes and the measured respective contributions of direct runoff and groundwater to these outflow hydrographs. Based on this great success, the same model has been used to simulate the response of a theoretical 100-meter wide and 10% sloped hillslope, with a 2 meter deep pervious soil and impervious bedrock. Three rain events have been tested: a 100 millimeter rainfall event over 10 days, over 1 day or over one hour. The simulated responses are hydrologically not realistic and especially the fast component of the response, that is generally observed in the real-world and explains flood events, is almost absent of the simulated response. Thinking a little about the whole problem, the simulation results appears totally logical according to the proposed model. The simulated response, in fact a recession hydrograph, corresponds to a piston flow of a relatively uniformly

  20. Pre- and post-processing of hydro-meteorological ensembles for the Norwegian flood forecasting system in 145 basins.

    NASA Astrophysics Data System (ADS)

    Jahr Hegdahl, Trine; Steinsland, Ingelin; Merete Tallaksen, Lena; Engeland, Kolbjørn

    2016-04-01

    Probabilistic flood forecasting has an added value for decision making. The Norwegian flood forecasting service is based on a flood forecasting model that run for 145 basins. Covering all of Norway the basins differ in both size and hydrological regime. Currently the flood forecasting is based on deterministic meteorological forecasts, and an auto-regressive procedure is used to achieve probabilistic forecasts. An alternative approach is to use meteorological and hydrological ensemble forecasts to quantify the uncertainty in forecasted streamflow. The hydrological ensembles are based on forcing a hydrological model with meteorological ensemble forecasts of precipitation and temperature. However, the ensembles of precipitation are often biased and the spread is too small, especially for the shortest lead times, i.e. they are not calibrated. These properties will, to some extent, propagate to hydrological ensembles, that most likely will be uncalibrated as well. Pre- and post-processing methods are commonly used to obtain calibrated meteorological and hydrological ensembles respectively. Quantitative studies showing the effect of the combined processing of the meteorological (pre-processing) and the hydrological (post-processing) ensembles are however few. The aim of this study is to evaluate the influence of pre- and post-processing on the skill of streamflow predictions, and we will especially investigate if the forecasting skill depends on lead-time, basin size and hydrological regime. This aim is achieved by applying the 51 medium-range ensemble forecast of precipitation and temperature provided by the European Center of Medium-Range Weather Forecast (ECMWF). These ensembles are used as input to the operational Norwegian flood forecasting model, both raw and pre-processed. Precipitation ensembles are calibrated using a zero-adjusted gamma distribution. Temperature ensembles are calibrated using a Gaussian distribution and altitude corrected by a constant gradient

  1. Reducing uncertainty in the selection of bi-variate distributions of flood peaks and volumes using copulas and hydrological process-based model selection

    NASA Astrophysics Data System (ADS)

    Szolgay, Jan; Gaál, Ladislav; Bacigál, Tomáš; Kohnová, Silvia; Blöschl, Günter

    2016-04-01

    Bi-variate distributions of flood peaks and flood event volumes are needed for a range of practical purposes including e.g. retention basin design and identifying extent and duration of flooding in flood hazard zones. However, the selection of the types of bi-variate distributions and estimating their parameters from observed peak-volume pairs are associated with far larger uncertainties compared to uni-variate distributions, since observed flood records of required length are rarely available. This poses a serious problem to reliable flood risk estimation in bi-variate design cases. The aim of this contribution was to shed light on the possibility of reducing uncertainties in the estimation of the dependence models/parameters from a regional perspective. The peak-volume relationships were modeled in terms of copulas. Flood events were classified according to their origin. In order to reduce the uncertainty in estimating flood risk, pooling and analyzing catchments of similar behavior according to flood process types was attempted. Most of the work reported in the literature so far did not direct the multivariate analysis toward discriminating certain types of models regionally according to specific runoff generation processes. Specifically, the contribution addresses these problems: - Are the peak-volume relationships of different flood types for a given catchment similar? - Are the peak-volume dependence structures between catchments in a larger region for given flood types similar? - Are some copula types more suitable for given flood process types and does this have consequences for reliable risk estimation? The target region is located in the northern parts of Austria, and consists of 72 small and mid-sized catchments. Instead of the traditional approach that deals with annual maximum floods, the current analysis includes all independent flood events in the region. 24 872 flood events from the period 1976-2007 were identified, and classified as synoptic, flash

  2. Deconvolving Flood Plain Dynamical Processes from Pedogenic Processes on Ancient Floodplains

    NASA Astrophysics Data System (ADS)

    Sheldon, N. D.

    2014-12-01

    Paleosols (fossil soils) preserved in ancient floodplain systems represent one of the most widely used and potentially powerful continental paleoclimatic archives. At the same time, to apply most of the quantitative paleoclimate proxies requires the deconvolution of floodplain dynamics from pedogenic processes. For example, a paleosol could be weakly developed because of low atmospheric CO2 levels, low amounts of precipitation, or because of short formation duration due to frequent channel avulsion. The interpretation of local floodplain dynamics in paleo-floodplain systems is often simplistic, assuming both straightforward uniformitarianism and also that a single vertical section represents that lateral diversity of environments, however, these assumptions have rarely, if ever, been put to the test. Herein, a variety of paleoclimatic and paleobiological proxies will be examined in well-preserved paleo-floodplain settings in Spain, Wyoming, and Montana to test those assumptions. Multi-proxy (phytolith, stable isotope) paleovegetation studies along paleo-floodplain transects in Montana (Miocene, Eocene) indicate substantial heterogeneity at the scale of tens to hundreds of meters, floodplain dynamics-driven succession, and cryptic paludal or everwet areas that are not recognizable purely on the basis of sedimentology. Similarly, rapidly aggrading floodplains in fluvial distributary systems (Spain, Miocene) or in dryland basins (Montana) often record significant mismatches between paleosol-based and paleobotanically based estimates of paleoprecipitation, likely due to variable sediment accumulation rates. Both of those sets of results indicate that single vertical sections are unlikely to represent the breadth floodplain environments and properties operating across paleo-floodplain systems. In contrast, newly described mineralogical proxies based on rock magnetics that can be used to reconstruct paleoclimatic/paleoenvironmental properties appear to be robust at the

  3. Miscible displacement of oils by carbon disulfide in porous media: Experiments and analysis

    NASA Astrophysics Data System (ADS)

    Berg, S.; Oedai, S.; Landman, A. J.; Brussee, N.; Boele, M.; Valdez, R.; van Gelder, K.

    2010-11-01

    The performance of carbon disulfide (CS2) as a novel agent for enhanced oil recovery has been investigated by conducting a comprehensive series of core flooding experiments where in porous rock, CS2 miscibly displaces "oil" (model fluids such as n-Decane, mineral oils, and crude oils) with a large range of viscosities and field-relevant flow rates. The recovery of oil and the three-dimensional spatial distribution of injected and displaced fluids were obtained from x-ray computed tomography. In all experiments, the displacement was unstable. The dominating displacement patterns were gravity under-run of the more dense CS2, channeling in higher permeable layers and viscous fingering. Since CS2 was fully miscible with all considered fluids, no difference in behavior between model fluids and crude oils was found. The recovery after injection of one pore volume of CS2 was parametrized using the dimensionless scaling groups Péclet number, gravity to viscous forces ratio G, and the logarithmic viscosity ratio R. At small viscosity ratios and large flow velocities (viscous dominated flow, small values of G), recoveries over 90% were observed. Slower flow and more viscous oils reduce the oil recovery.

  4. Tertiary recovery potential of CO2 flooding in Joffre Viking pool, Alberta

    SciTech Connect

    Ko, S.C.M.; Stanton, P.M.

    1983-01-01

    Significant tertiary oil recovery by CO2 flooding in a watered-out Joffre Viking sand unit in central Alberta, as determined in a preliminary feasibility study, prompted further detailed evaluation of the CO2 process. Consequently, reservoir simulation models are used in the study to further investigate the technical feasibility and prediction of CO2 flood performance. Using a Black Oil simulator (BETA II), history matching of primary and waterflood production performance on a selected portion of the Joffre Viking Pool involving 85 wells was undertaken. This step provided for proper initialization of fluid and pressure distribution and a reservoir description for the miscible CO2 flood model (COMP II). Sensitivity analysis and process optimization using a typical pattern approach were conducted to optimize the tertiary CO2 flood performance. Simulation results indicated that in the presence of a trapped oil saturation due to water blocking oil from contact by the injected CO2, a larger CO2 slug and/or a smaller water slug are required in a water-alternating-with-gas process for more efficient displacements. 13 references.

  5. Dynamic Heterogeneity in Interacting Miscible Polymer Blends

    NASA Astrophysics Data System (ADS)

    Gaikwad, Ashish; Lodge, Timothy

    2008-03-01

    Dynamic heterogeneity leading to time-temperature superposition (tTS) failure has been widely reported in non-interacting/weakly interacting miscible polymer blends. However, coupling of the component dynamic response in blends, even with a huge dynamic asymmetry in the pure components, is possible with H-bonding interactions. This study is focused on finding the minimum level of interaction necessary for thermo-rheological simplicity in blends. Blends of styrene-co-vinylphenol (PSVPh) and poly(vinyl methyl ether) (PVME) were chosen. Incorporation of styrene provides an effective way to modulate H-bonding interactions in the system. Linear viscoelastic data indicate that tTS fails for PS/PVME blends, whereas data obtained for different PVPh/PVME blends showed that tTS was obeyed a over wide temperature range. For PSVPh/PVME blends with low PSVPh content, tTS was successful. This suggests that the presence of alternating styrene and vinyl phenol units was insufficient for dynamic response decoupling. Further studies are in progress, with varying vinyl phenol content in PSVPh, to explore the influence of H-bonding on dynamic heterogeneity and blend dynamics.

  6. CO{sub 2} huff-n-puff process in a light oil shallow carbonate reservoir. Annual report, January 1, 1996--December 31, 1996

    SciTech Connect

    Prieditis, J.; Wehner, S.

    1998-01-01

    The application of cyclic CO{sub 2}, often referred to as the CO{sub 2} Huff-n-Puff process, may find its niche in the maturing waterfloods of the Permian Basin. Coupling the CO{sub 2} H-n-P process to miscible flooding applications could provide the needed revenue to sufficiently mitigate near-term negative cash flow concerns in the capital intensive miscible projects. Texaco Exploration & Production Inc. and the U.S. Department of Energy have teamed up in an attempt to develop the CO{sub 2} Huff-n-Puff process in the Grayburg and San Andres formations; a light oil, shallow shelf carbonate reservoir that exists throughout the Permian Basin. A significant amount of oil reserves are located in carbonate reservoirs. Specifically, the carbonates deposited in shallow shelf (SSC) environments make up the largest percentage of known reservoirs within the Permian Basin of North America. Many of these known resources have been under waterflooding operations for decades and are at risk of abandonment if crude oil recoveries cannot be economically enhanced. The selected site for this demonstration project is the Central Vacuum Unit waterflood in Lea County, New Mexico. Miscible CO{sub 2} flooding is the process of choice for enhancing recovery of light oils and already accounts for over 12% of the Permian Basin`s daily production. There are significant probable reserves associated with future miscible CO{sub 2} projects. However, many are marginally economic at current market conditions due to large up-front capital commitments for a peak response which may be several years in the future. The resulting negative cash-flow is sometimes too much for an operator to absorb. The CO{sub 2} H-n-P process is being investigated as a near-term option to mitigate the negative cash-flow situation--allowing acceleration of inventoried miscible CO{sub 2} projects when coupled together.

  7. Rheology of miscible polymer blends with hydrogen bonding

    NASA Astrophysics Data System (ADS)

    Yang, Zhiyi

    Poly(4-vinylphenol) (PVPh) was blended with four different polymers: poly(vinyl methyl ether) (PVME), poly(vinyl acetate) (PVAc), poly(2-vinylpyridine) (P2VP), and poly(4-vinylpyridine) (P4VP) by solvent casting. The miscibility of these four PVPh-based blend systems was investigated using differential scanning calorimetry (DSC) and the composition-dependent glass transition temperature (Tg) was predicted by a thermodynamic theory. The hydrogen bonds between phenolic group in PVPh and ether group, carbonyl group or pyridine group was confirmed by Fourier transform infrared (FTIR) spectroscopy. The fraction of hydrogen bonds was calculated by the Coleman-Graf-Painter association model. Linear dynamic viscoelasticity of four PVPh-based miscible polymer blends with hydrogen bonding was investigated. Emphasis was placed on investigating how the linear dynamic viscoelasticity of miscible polymer blends with specific interaction might be different from that of miscible polymer blends without specific interaction. We have found that an application of time-temperature superposition (TTS) to the PVPh-based miscible blends with intermolecular hydrogen bonding is warranted even when the difference in the component glass transition temperatures is as large as about 200°C, while TTS fails for miscible polymer blends without specific interactions. On the basis of such an observation, we have concluded that hydrogen bonding suppressed concentration fluctuations in PVPh-based miscible blends. It has been found that both the intra-association (self-association) of the phenoxy hydroxyl groups in PVPh and inter-association (intermolecular interactions) between the constituent components have a profound influence on the frequency dependence of dynamic moduli in the terminal region of the PVPh-based miscible blend systems investigated. Hydrogenated functional polynorbornenes (HFPNBs) were synthesized and they were used to investigate the miscibility and rheology of HFPNB

  8. Uphill diffusion and phase separation in partially miscible multicomponent mixtures

    NASA Astrophysics Data System (ADS)

    He, Ping; Raghavan, Ashwin; Ghoniem, Ahmed

    2015-11-01

    The partially miscible multicomponent mixtures, which are frequently encountered in green chemistry processes, often exhibit complicated behaviors, and are critical to the production rate, energy efficiency, and pollution controls. Recent studies have been mainly focused on phase behaviors. However, the coupled phase equilibrium and transport process, which may be the answer to phase separations observed in experiments, is not well researched. Here, we present a numerical and theoretical study on coupled mixing of heavy oil and supercritical water, and the results of our state-of-art modeling agree with experimental measurements. We find that due to the non-ideal diffusion driving force, (1) strong uphill diffusion of heavy oil fractions occurs, (2) a new heavy oil phase is separated starting from the plait point, and heavy fractions become highly concentrated, and (3) water diffusion initially overshoots in oil, and is expelled lately. Finally, we conclude our analysis applicable to different molecules and conditions. The authors thank Saudi Aramco for supporting this work (contract number 6600023444).

  9. Estimating the Response of Physical Processes in the South San Francisco Bay for Flood Stage Frequency Analysis

    NASA Astrophysics Data System (ADS)

    Andes, L.; Wu, F.; MacWilliams, M.; Lu, C.; Lo, J.

    2012-12-01

    Coastal flooding in the far south San Francisco Bay (SSFB) can be a function of astronomical tide, residual tide, in-bay wind speed and direction and fluvial discharge. These physical processes and coastal levee failure were considered as input parameters into a Monte Carlo Simulation (MCS) to estimate coastal flood stage frequency in the SSFB. Limited data is available in the SSFB to estimate the contribution of these physical processes to coastal flood statistics. Over 100 years of measured water surface elevation (WSE) is available at the San Francisco tide station which can be used as input to hydrodynamic model simulations to estimate the WSE response in the SSFB. Data sampling criteria have been developed to select significant events at the San Francisco tide station for data transfer to the project site and statistical analysis. The coincidently sampled astronomical and residual tides at the San Francisco tide station were analyzed to cover the full range of the combinations of astronomical and residual tides that contribute to coastal flood statistics at the project site. A look-up table of astronomical and residual tide in the form of WSE responses at the project site from the hydrodynamic simulations was established for the interpolation in the MCS. The hydrodynamic model simulations indicated that the higher-high astronomical tides between 5.15 and 7.25 feet MLLW amplifies with a factor of 1.40 to 1.90 as a function of tidal frequency and water depth, including tidal range. The residual tide varies minimally as it propagates into the SSFB. In-Bay wind set-up from a significant event was found to contribute on the order of one foot to the total WSE in the SSFB; however, wind events with strong magnitudes along the primary axis of the bay occur infrequently making an insignificant contribution to the overall flood statistics. The fluvial discharges of Guadalupe River and Coyote Creek were considered in the hydrodynamic simulations as they are located

  10. Assessment Approach for Identifying Compatibility of Restoration Projects with Geomorphic and Flooding Processes in Gravel Bed Rivers.

    PubMed

    DeVries, Paul; Aldrich, Robert

    2015-08-01

    A critical requirement for a successful river restoration project in a dynamic gravel bed river is that it be compatible with natural hydraulic and sediment transport processes operating at the reach scale. The potential for failure is greater at locations where the influence of natural processes is inconsistent with intended project function and performance. We present an approach using practical GIS, hydrologic, hydraulic, and sediment transport analyses to identify locations where specific restoration project types have the greatest likelihood of working as intended because their function and design are matched with flooding and morphologic processes. The key premise is to identify whether a specific river analysis segment (length ~1-10 bankfull widths) within a longer reach is geomorphically active or inactive in the context of vertical and lateral stabilities, and hydrologically active for floodplain connectivity. Analyses involve empirical channel geometry relations, aerial photographic time series, LiDAR data, HEC-RAS hydraulic modeling, and a time-integrated sediment transport budget to evaluate trapping efficiency within each segment. The analysis segments are defined by HEC-RAS model cross sections. The results have been used effectively to identify feasible projects in a variety of alluvial gravel bed river reaches with lengths between 11 and 80 km and 2-year flood magnitudes between ~350 and 1330 m(3)/s. Projects constructed based on the results have all performed as planned. In addition, the results provide key criteria for formulating erosion and flood management plans. PMID:25910870

  11. Assessment Approach for Identifying Compatibility of Restoration Projects with Geomorphic and Flooding Processes in Gravel Bed Rivers

    NASA Astrophysics Data System (ADS)

    DeVries, Paul; Aldrich, Robert

    2015-08-01

    A critical requirement for a successful river restoration project in a dynamic gravel bed river is that it be compatible with natural hydraulic and sediment transport processes operating at the reach scale. The potential for failure is greater at locations where the influence of natural processes is inconsistent with intended project function and performance. We present an approach using practical GIS, hydrologic, hydraulic, and sediment transport analyses to identify locations where specific restoration project types have the greatest likelihood of working as intended because their function and design are matched with flooding and morphologic processes. The key premise is to identify whether a specific river analysis segment (length ~1-10 bankfull widths) within a longer reach is geomorphically active or inactive in the context of vertical and lateral stabilities, and hydrologically active for floodplain connectivity. Analyses involve empirical channel geometry relations, aerial photographic time series, LiDAR data, HEC-RAS hydraulic modeling, and a time-integrated sediment transport budget to evaluate trapping efficiency within each segment. The analysis segments are defined by HEC-RAS model cross sections. The results have been used effectively to identify feasible projects in a variety of alluvial gravel bed river reaches with lengths between 11 and 80 km and 2-year flood magnitudes between ~350 and 1330 m3/s. Projects constructed based on the results have all performed as planned. In addition, the results provide key criteria for formulating erosion and flood management plans.

  12. The role of molecular diffusion processes in tertiary carbon dioxide flooding

    SciTech Connect

    Grogan, A.T.; Pinczewski, W.V.

    1984-04-01

    The role of molecular diffusion in the mobilization of waterflood residual oil is examined. A simple numerical model which simulates the swelling of residual oil blobs by carbon dioxide diffusion through a blocking water phase is developed. The diffusion times calculated using the model are compared with the corresponding times in laboratory micromodel and core flood experiments. The comparison shows that diffusion plays a major role in the mobilization and recovery of waterflood residual oil and that high unit or local displacement efficiencies are achieved when there is sufficient time for diffusion to significantly swell the oil. For the length scales normally associated with laboratory core floods diffusion is shown to be sufficiently rapid to effectively reduce the adverse effects of bypassing on overall recovery efficiency. This is not so for field floods where bypassing of oil by injected carbon dioxide may be expected to occur on a much larger scale.

  13. Component Dynamics and the Corresponding Compositional Heterogeneity in Bulk and Thin Film Miscible Polymer Blends

    NASA Astrophysics Data System (ADS)

    Yang, Hengxi; Green, Peter

    2014-03-01

    Miscible polymer blends are known to be compositional heterogeneous, due to self-concentration and thermally driven compositional fluctuation. In this work we investigate the segmental dynamics of poly(vinyl methyl ether) (PVME) in miscible polymer blends of polystyrene (PS) and PVME, using broadband dielectric spectroscopy, and manifest the correspondence between the component dynamics and the compositional heterogeneity in miscible blends. A single α-relaxation is observed at high temperatures, T, obeying Vogel-Fulcher relation, whereas two separate relaxations exist at low T. One relaxation, slower and exhibiting a strong T-dependence, is associated with an average local composition with smaller PVME fraction. The other relaxation, known as α'-relaxation, is weakly T-dependent and Arrhenius-like at low T; it reflects the PVME-rich domains within the confines of glassy PS-rich domains. In PVME/PS thin films confined between aluminum (Al) substrates, an additional relaxation process, due to PVME chains that preferentially segregated to Al interfaces, emerges.

  14. Estimation of minimum miscibility pressure (MMP) of CO2 and liquid n-alkane systems using an improved MRI technique.

    PubMed

    Liu, Yu; Jiang, Lanlan; Song, Yongchen; Zhao, Yuechao; Zhang, Yi; Wang, Dayong

    2016-02-01

    Minimum miscible pressure (MMP) of gas and oil system is a key parameter for the injection system design of CO2 miscible flooding. Some industrial standard approaches such as the experiment using a rising bubble apparatus (RBA), the slim tube tests (STT), the pressure-density diagram (PDD), etc. have been applied for decades to determine the MMP of gas and oil. Some theoretical or experiential calculations of the MMP were also applied to the gas-oil miscible system. In the present work, an improved technique based on our previous research for the estimation of the MMP by using magnetic resonance imaging (MRI) was proposed. This technique was then applied to the CO2 and n-alkane binary and ternary systems to observe the mixing procedure and to study the miscibility. MRI signal intensities, which represent the proton concentration of n-alkane in both the hydrocarbon rich phase and the CO2 rich phase, were plotted as a reference for determining the MMP. The accuracy of the MMP obtained by using this improved technique was enhanced comparing with the data obtained from our previous works. The results also show good agreement with other established techniques (such as the STT) in previous published works. It demonstrates increases of MMPs as the temperature rise from 20 °C to 37.8 °C. The MMPs of CO2 and n-alkane systems are also found to be proportional to the carbon number in the range of C10 to C14. PMID:26523648

  15. Model parameters conditioning on regional hydrologic signatures for process-based design flood estimation in ungauged basins.

    NASA Astrophysics Data System (ADS)

    Biondi, Daniela; De Luca, Davide Luciano

    2015-04-01

    The use of rainfall-runoff models represents an alternative to statistical approaches (such as at-site or regional flood frequency analysis) for design flood estimation, and constitutes an answer to the increasing need for synthetic design hydrographs (SDHs) associated to a specific return period. However, the lack of streamflow observations and the consequent high uncertainty associated with parameter estimation, usually pose serious limitations to the use of process-based approaches in ungauged catchments, which in contrast represent the majority in practical applications. This work presents the application of a Bayesian procedure that, for a predefined rainfall-runoff model, allows for the assessment of posterior parameters distribution, using the limited and uncertain information available for the response of an ungauged catchment (Bulygina et al. 2009; 2011). The use of regional estimates of river flow statistics, interpreted as hydrological signatures that measure theoretically relevant system process behaviours (Gupta et al. 2008), within this framework represents a valuable option and has shown significant developments in recent literature to constrain the plausible model response and to reduce the uncertainty in ungauged basins. In this study we rely on the first three L-moments of annual streamflow maxima, for which regressions are available from previous studies (Biondi et al. 2012; Laio et al. 2011). The methodology was carried out for a catchment located in southern Italy, and used within a Monte Carlo scheme (MCs) considering both event-based and continuous simulation approaches for design flood estimation. The applied procedure offers promising perspectives to perform model calibration and uncertainty analysis in ungauged basins; moreover, in the context of design flood estimation, process-based methods coupled with MCs approach have the advantage of providing simulated floods uncertainty analysis that represents an asset in risk-based decision

  16. Mapping hazards from glacier lake outburst floods based on modelling of process cascades at Lake 513, Carhuaz, Peru

    NASA Astrophysics Data System (ADS)

    Schneider, D.; Huggel, C.; Cochachin, A.; Guillén, S.; García, J.

    2014-01-01

    Recent warming has had enormous impacts on glaciers and high-mountain environments. Hazards have changed or new ones have emerged, including those from glacier lakes that form as glaciers retreat. The Andes of Peru have repeatedly been severely impacted by glacier lake outburst floods in the past. An important recent event occurred in the Cordillera Blanca in 2010 when an ice avalanche impacted a glacier lake and triggered an outburst flood that affected the downstream communities and city of Carhuaz. In this study we evaluate how such complex cascades of mass movement processes can be simulated coupling different physically-based numerical models. We furthermore develop an approach that allows us to elaborate corresponding hazard maps according to existing guidelines for debris flows and based on modelling results and field work.

  17. Miscibility comparison for three refrigerant mixtures and four component refrigerants

    SciTech Connect

    Kang, H.M.; Pate, M.B.

    1999-07-01

    Miscibility data were taken and compared for seven different refrigerants when mixed with the same polyol ester (POE) lubricant. Four of the seven refrigerants were single-component refrigerants while three of the refrigerants were mixtures composed of various combinations of the pure refrigerants. The purpose of this research was to investigate the difference in miscibility characteristics between refrigerant mixtures and their respective component refrigerants. The POE lubricant was a penta erythritol mixed-acid type POE which has a viscosity ISO32. The four pure refrigerants were R-32, R-125, R-134a, and R-143a and the three refrigerant mixtures were R-404A, R407C, and R-410A. The miscibility tests were performed in a test facility consisting of a series of miniature test cells submerged in a constant temperature bath. The test cells were constructed to allow for complete visibility of the refrigerant/lubricant mixtures under all test conditions. The tests were performed over a concentration range of 0 to 100% and a temperature range of {minus}40 to 194 F. The miscibility test results for refrigerant mixtures are compared to component refrigerants. In all cases, the refrigerant mixtures appear to have better miscibility than their most immiscible pure component.

  18. Optical Studies of model binary miscibility gap system

    NASA Technical Reports Server (NTRS)

    Lacy, L. L.; Witherow, W. K.; Facemire, B. R.; Nishioka, G. M.

    1982-01-01

    In order to develop a better understanding of separation processes in binary miscibility gap metal alloys, model transparent fluid systems were studied. The system selected was diethylene glycol-ethyl salicylate which has convenient working temperatures (288 to 350 K), low toxicity, and is relatively easy to purify. The system is well characterized with respect to its phase diagram, density, surface and interfacial tensions, viscosity and other pertinent physical properties. Studies of migration of the dispersed phase in a thermal gradient were performed using conventional photomicroscopy. Velocities of the droplets of the dispersed phase were measured and compared to calculated rates which included both Stokes and thermal components. A holographic microscopy system was used to study growth, coalescence, and particle motions. Sequential holograms allowed determination of particle size distribution changes with respect to time and temperature. Holographic microscopy is capable of recording particle densities up to 10 to the 7th power particles/cu cm and is able to resolve particles of the order of 2 to 3 microns in diameter throughout the entire volume of the test cell. The reconstructed hologram produces a wavefront that is identical to the original wavefront as it existed when the hologram was made. The reconstructed wavefront is analyzed using a variety of conventional optical methods.

  19. CO2 Huff-n-Puff Process in a Light Oil Shallow Shelf Carbonate Reservoir

    SciTech Connect

    Boomer, R.J.; Cole, R.; Kovar, M.; Prieditis, J.; Vogt, J.; Wehner, S.

    1999-02-24

    The application cyclic CO2, often referred to as the CO2 Huff-n-Puff process, may find its niche in the maturing waterfloods of the Permian Basin. Coupling the CO2 Huff-n-Puff process to miscible flooding applications could provide the needed revenue to sufficiently mitigate near-term negative cash flow concerns in capital-intensive miscible projects. Texaco Exploration and Production Inc. and the US Department of Energy have teamed up in a attempt to develop the CO2 Huff-n-Puff process in the Grayburg and San Andres formations which are light oil, shallow shelf carbonate reservoirs that exist throughout the Permian Basin. This cost-shared effort is intended to demonstrate the viability of this underutilized technology in a specific class of domestic reservoir.

  20. Miscibility studies on blends containing telechelic supramolecular polymers

    NASA Astrophysics Data System (ADS)

    Wrue, Michelle; Anthamatten, Mitchell

    2007-03-01

    The incorporation of associating end groups influences the phase behavior of polymer blends. We are studying the effects of the incorporation of strong, site-selective, hydrogen-bonding groups in various polymer blend systems. We have synthesized several telechelic ureidopyrimidone (UPy) functionalized polymers. These self-complimentary functional groups have the ability to form four hydrogen bonds. When these groups are incorporated into a polymer blend, the miscibility is altered. Laser light scattering has been employed to study the phase behavior of these systems. Data from systems in which only one polymer was functionalized indicate a reduced miscibility when compared with the unfunctionalized parent blend. We are also investigating the effect of functionalizing both polymers of the blend with UPy end groups. We predict enhanced miscibility in such systems.

  1. COSOLVENCY OF PARTIALLY MISCIBLE ORGANIC SOLVENTS ON THE SOLUBILITY OF HYDROPHOBIC ORGANIC CHEMICALS

    EPA Science Inventory

    The cosolvency of completely miscible organic solvents (CMOSs) and partially miscible organic solvents (PMOSs) on the solubility of hydrophobic organic chemicals (HOCs) was examined, with an emphasis on PMOSs. Measured solubilities were compared with predictions from the log- lin...

  2. Process-orientated simulation of tillage practices and land use change to optimize distributed flood control measures

    NASA Astrophysics Data System (ADS)

    Disse, M.; Rieger, W.

    2009-04-01

    Not only climate change affects hydrological systems but also land use change and agricultural tillage practises have an important impact on infiltration and runoff generation. In the last five to six decades monocropping, drainage and rectification of small rivers were carried out to optimize crop yields and economic benefits. However, in recent years more holistic and sustainable management concepts are required. The advantages of ecological management of land, soil and water resources are manifold: the biodiversity is higher, the buffer function of soils will be conserved and both low water and floods are positive affected. The target of the presented research project which is financed by the Bavarian environment agency, is to establish an optimal flood retention concept in a mesoscale catchment of 150 km² which emphasizes ecological flood measures like best tillage practices, small retention basins and renaturation of small rivers. To quantify the effects of these measures the water balance model WaSiM-ETH was used. The grid-based water flow and balance simulation model WaSiM-ETH is a well-established tool for investigating the spatial and temporal variability of hydrological processes in complex river basins. The model can be seen as a reasonable compromise between detailed physical basis and minimum data requirements (http://www.wasim.ch/en/index.html). WaSiM was coupled with a 2d-ground water model and an additional drainage tool. Different vegetation was parameterized with high spatial and temporal resolution. Additionally, future climate scenarios like the extension of vegetation periods were considered. The effectiveness of decentralized retention basins could be simulated by a new implemented see storage tool. The presentation will give quantitative results for different flood control measures. The pros and cons of physically based approaches in hydrological modelling will be discussed.

  3. Multiple flow processes accompanying a dam-break flood in a small upland watershed, Centralia, Washington

    USGS Publications Warehouse

    Costa, John E.

    1994-01-01

    On October 5, 1991, following 35 consecutive days of dry weather, a 105-meter long, 37-meter wide, 5.2-meter deep concrete-lined watersupply reservoir on a hillside in the eastern edge of Centralia, Washington, suddenly failed, sending 13,250 cubic meters of water rushing down a small, steep tributary channel into the city. Two houses were destroyed, several others damaged, mud and debris were deposited in streets, on lawns, and in basements over four city blocks, and 400 people were evacuated. The cause of failure is believed to have been a sliding failure along a weak seam or joint in the siltstone bedrock beneath the reservoir, possibly triggered by increased seepage into the rock foundation through continued deterioration of concrete panel seams, and a slight rise (0.6 meters) in the pool elevation. A second adjacent reservoir containing 18,900 cubic meters of water also drained, but far more slowly, when a 41-cm diameter connecting pipe was broken by the landslide. The maximum discharge resulting from the dam-failure was about 71 cubic meters per second. A reconstructed hydrograph based on the known reservoir volume and calculated peak discharge indicates the flood duration was about 6.2 minutes. Sedimentologic evidence, high-water mark distribution, and landforms preserved in the valley floor indicate that the dam failure flood consisted of two flow phases: an initial debris flow that deposited coarse bouldery sediment along the slope-area reach as it lost volume, followed soon after by a water-flood that achieved a stage about one-half meter higher than the debris flow. The Centralia dam failure is one of three constructed dams destroyed by rapid foundation failure that defines the upper limits of an envelope curve of peak flood discharge as a function of potential energy for failed constructed dams worldwide.

  4. Flow prediction using stochastic emulators of flood wave propagation process: middle Vistula case study

    NASA Astrophysics Data System (ADS)

    Romanowicz, Renata; Karamuz, Emilia; Kochanek, Krzysztof

    2014-05-01

    Flow predictions along the river reach are required for flood protection, flood risk assessment and also for the planning of water infrastructures and water management. Due to uncertainties involved in hydro-meteorological observations and mathematical modelling, the predictions are always uncertain. Their uncertainty increases with an increase of the time horizon of the prediction - e.g. when forecasts of flow are required many days ahead. Apart from the uncertainty, also the speed of forecast acquisition might also be of concern, in particular when fast preventive actions should be taken to issue flood warning to the public, or some water management actions should be performed. In these cases, the stochastic emulators of flood wave propagation might be very useful. The emulators can be based on available data but also be built using the modelled flows along the river in the absence of the required observations. The middle River Vistula reach stretches between Zawichost and Warsaw and is 100 km long. Two distributed flow routing models were built for the reach based on the detailed river channel and floodplain geometry data. These models are used for the temporal and spatial interpolation of the water level observations available at only 5 cross-sections and in the form of daily averages of water levels. The observations span over 50 years, but they are irregular, with long periods missing either flow or level data. The observed and modelled water level data were used to build stochastic emulators in the form of a nonlinear transformation of water levels at cross-sections along the river reach. The validation of the emulators and the comparison of their performance are done using the available observations of water levels at those cross-sections. A discussion is given on the uncertainty of predictions and the application of emulators to on-line forecasting. This work was partly supported by the project "Stochastic flood forecasting system (The River Vistula reach

  5. Assessment of flood hazard areas at a regional scale using an index-based approach and Analytical Hierarchy Process: Application in Rhodope-Evros region, Greece.

    PubMed

    Kazakis, Nerantzis; Kougias, Ioannis; Patsialis, Thomas

    2015-12-15

    The present study introduces a multi-criteria index to assess flood hazard areas in a regional scale. Accordingly, a Flood Hazard Index (FHI) has been defined and a spatial analysis in a GIS environment has been applied for the estimation of its value. The developed methodology processes information of seven parameters namely flow accumulation, distance from the drainage network, elevation, land use, rainfall intensity and geology. The initials of these criteria gave the name to the developed method: "FIGUSED". The relative importance of each parameter for the occurrence and severity of flood has been connected to weight values. These values are calculated following an "Analytical Hierarchy Process", a method originally developed for the solution of Operational Research problems. According to their weight values, information of the different parameters is superimposed, resulting to flood hazard mapping. The accuracy of the method has been supported by a sensitivity analysis that examines a range for the weights' values and corresponding to alternative scenarios. The presented methodology has been applied to an area in north-eastern Greece, where recurring flood events have appeared. Initially FIGUSED method resulted to a Flood Hazard Index (FHI) and a corresponding flood map. A sensitivity analysis on the parameters' values revealed some interesting information on the relative importance of each criterion, presented and commented in the Discussion section. Moreover, the sensitivity analysis concluded to a revised index FHIS (methodology named FIGUSED-S) and flood mapping, supporting the robustness of FIGUSED methodology. A comparison of the outcome with records of historical flood events confirmed that the proposed methodology provides valid results. PMID:26318691

  6. Stability of Miscible Displacements Across Stratified Porous Media

    SciTech Connect

    Shariati, Maryam; Yortsos, Yanis C.

    2000-09-11

    This report studied macro-scale heterogeneity effects. Reflecting on their importance, current simulation practices of flow and displacement in porous media were invariably based on heterogeneous permeability fields. Here, it was focused on a specific aspect of such problems, namely the stability of miscible displacements in stratified porous media, where the displacement is perpendicular to the direction of stratification.

  7. A Methodology For Flood Vulnerability Analysis In Complex Flood Scenarios

    NASA Astrophysics Data System (ADS)

    Figueiredo, R.; Martina, M. L. V.; Dottori, F.

    2015-12-01

    Nowadays, flood risk management is gaining importance in order to mitigate and prevent flood disasters, and consequently the analysis of flood vulnerability is becoming a key research topic. In this paper, we propose a methodology for large-scale analysis of flood vulnerability. The methodology is based on a GIS-based index, which considers local topography, terrain roughness and basic information about the flood scenario to reproduce the diffusive behaviour of floodplain flow. The methodology synthetizes the spatial distribution of index values into maps and curves, used to represent the vulnerability in the area of interest. Its application allows for considering different levels of complexity of flood scenarios, from localized flood defence failures to complex hazard scenarios involving river reaches. The components of the methodology are applied and tested in two floodplain areas in Northern Italy recently affected by floods. The results show that the methodology can provide an original and valuable insight of flood vulnerability variables and processes.

  8. Climate change impacts on the seasonality and generation processes of floods - projections and uncertainties for catchments with mixed snowmelt/rainfall regimes

    NASA Astrophysics Data System (ADS)

    Vormoor, K.; Lawrence, D.; Heistermann, M.; Bronstert, A.

    2015-02-01

    Climate change is likely to impact the seasonality and generation processes of floods in the Nordic countries, which has direct implications for flood risk assessment, design flood estimation, and hydropower production management. Using a multi-model/multi-parameter approach to simulate daily discharge for a reference (1961-1990) and a future (2071-2099) period, we analysed the projected changes in flood seasonality and generation processes in six catchments with mixed snowmelt/rainfall regimes under the current climate in Norway. The multi-model/multi-parameter ensemble consists of (i) eight combinations of global and regional climate models, (ii) two methods for adjusting the climate model output to the catchment scale, and (iii) one conceptual hydrological model with 25 calibrated parameter sets. Results indicate that autumn/winter events become more frequent in all catchments considered, which leads to an intensification of the current autumn/winter flood regime for the coastal catchments, a reduction of the dominance of spring/summer flood regimes in a high-mountain catchment, and a possible systematic shift in the current flood regimes from spring/summer to autumn/winter in the two catchments located in northern and south-eastern Norway. The changes in flood regimes result from increasing event magnitudes or frequencies, or a combination of both during autumn and winter. Changes towards more dominant autumn/winter events correspond to an increasing relevance of rainfall as a flood generating process (FGP) which is most pronounced in those catchments with the largest shifts in flood seasonality. Here, rainfall replaces snowmelt as the dominant FGP primarily due to increasing temperature. We further analysed the ensemble components in contributing to overall uncertainty in the projected changes and found that the climate projections and the methods for downscaling or bias correction tend to be the largest contributors. The relative role of hydrological

  9. Modelling cascading and erosional processes for glacial lake outburst floods in the Quillcay catchment, Huaraz, Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Baer, Patrick; Huggel, Christian; Frey, Holger; Chisolm, Rachel; McKinney, Daene; McArdell, Brian; Portocarrero, Cesar; Cochachin, Alejo

    2016-04-01

    Huaraz as the largest city in Cordillera Blanca has faced a major disaster in 1941, when an outburst flood from Lake Palcacocha killed several thousand people and caused widespread destruction. Recent studies on glacial lake outburst flood (GLOF) modelling and early warning systems focussed on Lake Palcacocha which has regrown after the 1941 event, from a volume of half a million m3 in 1974 to a total volume of more than 17 million m3 today. However, little research has been conducted so far concerning the situation of other lakes in the Quillcay catchment, namely Lake Tullparaju (12 mill. m3) and Cuchillacocha (2.5 mill. m3), which both also pose a threat to the city of Huaraz. In this study, we modelled the cascading processes at Lake Tullparaju and Lake Cuchillacocha including rock/ice avalanches, flood wave propagation in the lake and the resulting outburst flood and debris flows. We used the 2D model RAMMS to simulate ice avalanches. Model output was used as input for analytical 2D and 3D calculations of impact waves in the lakes that allowed us to estimate dam overtopping wave height. Since the dimension of the hanging glaciers above all three lakes is comparable, the scenarios in this study have been defined similar to the previous study at Lake Palcacocha. The flow propagation model included sediment entrainment in the steeper parts of the catchment, adding up to 50% to the initial flow volume. The results for total travel time as well as for inundated areas and flow depth and velocity in the city of Huaraz are comparable to the previous studies at Lake Palcacocha. This underlines the importance of considering also these lakes within an integral hazard analysis for the city of Huaraz. A main challenge for modelling GLOFs in the Quillcay catchment using RAMMS is the long runout distance of over 22 km combined with the very low slope gradient of the river. Further studies could improve the process understanding and could focus on more detailed investigations

  10. Utilizing Multi-Sensor Data Products and high-resolution flood model in Analyzing North African Hydrological Processes

    NASA Astrophysics Data System (ADS)

    Thengumthara, K.; Policelli, F.; Habib, S.; David, J. L.; Melocik, K. A.; Huffman, G. J.; Anderson, M. C.; Ali, A. B.; Bacha, S.

    2013-12-01

    North Africa is an arid region characterized by isolated extreme events such as floods and droughts. Our present understanding of hydrological processes over North Africa is limited due to low rainfall, mixed response of evaporation to temperature and soil moisture gradients, and lack of high-resolution ground measurements. Remote sensing is an excellent way to obtain near real- time data of high spatial and temporal resolution. Satellite estimates of rainfall and evapotranspiration (ET) have uncertainties due to topography, land-sea contrast, complex weather, and climate variability for high-elevated regions. Generally for arid regions, the satellite precipitation instruments are sensitive to soil moisture and land surface geometry. This study analyzes different components of hydrological processes over North Africa based on remote sensing data such as precipitation (NASA-TMPA, CMORPH and PERSIANN), evaporation (ALEXI and MODIS), and elevation (SRTM) along with ground measurements and model simulations. Here we use the Coupled Routing and Excess STorage (CREST) hydrological model-version 2.0, which was originally developed by NASA-GSFC and the University of Oklahoma [Wang J et al., 2011]. The model is driven by real time TMPA and climatological PET, interpolated to model grids. The flexible simulation and calibration enables the model to provide high-resolution runoff and water depth at each time step. Our study mainly focuses on two major basins such as Medjerda over Tunisia and the Sebou basin of Morocco. Case studies of flood events over North Africa were analyzed based on CREST model simulations with respect to ground measurements. The floods are mainly modulated by rainfall associated with synoptic frontal and tropical plumes and orographic mesoscale systems. Occurrences of peak floods simulated by CREST are comparable with diagnostics such as vertically integrated moisture convergence, stratiform and convective precipitation from ECMWF reanalysis. These were

  11. The role of molecular diffusion processes in tertiary CO/sub 2/ flooding

    SciTech Connect

    Grogan, A.T.; Pinczewski, W.V.

    1987-05-01

    This paper examines the role of molecular diffusion in the mobilization of waterflood residual oil. A numerical model that simulates the swelling of residual oil blobs by CO/sub 2/ diffusion through a blocking water phase is developed. The diffusion times calculated with the model are compared with those calculated in laboratory micromodel and coreflood experiments. The comparison shows that diffusion plays a major role in the mobilization and recovery of waterflood residual oil and that high unit or local displacement efficiencies are achieved when there is sufficient time for diffusion to swell the oil significantly. For the length scales normally associated with laboratory corefloods, diffusion is sufficiently rapid to reduce effectively the adverse effects of bypassing on overall recovery efficiency. This is not so for field floods, where bypassing of oil by injected CO/sub 2/ may be expected to occur on a much larger scale.

  12. Aerobic biodegradation process of petroleum and pathway of main compounds in water flooding well of Dagang oil field.

    PubMed

    Cai, Minmin; Yao, Jun; Yang, Huaijun; Wang, Ruixia; Masakorala, Kanaji

    2013-09-01

    Aerobic biodegradation of crude oil and its pathways were investigated via in vitro culture and GC-MS analysis in water flooding wells of Dagang oil field. The in vitro aerobic culture lasted 90 days when 99.0% of n-alkanes and 43.03-99.9% of PAHs were degraded and the biomarkers and their ratios were changed. The spectra of components in the residual oil showed the similar biodegradation between aerobic process of 90 days and degradation in reservoir which may last for some millions years, and the potential of serious aerobic biodegradation of petroleum in reservoir. 24 Metabolites compounds were separated and identified from aerobic culture, including fatty acid, naphthenic acid, aromatic carboxylic acid, unsaturated acid, alcohols, ketones and aldehydes. The pathways of alkanes and aromatics were proposed, which suggests that oxidation of hydrocarbon to organic acid is an important process in the aerobic biodegradation of petroleum. PMID:23867530

  13. Calcium Carbonate Crystal Growth in Porous Media, in the presence of Water Miscible and Non-Miscible Organic Fluids

    NASA Astrophysics Data System (ADS)

    Jaho, Sofia; Sygouni, Varvara; Paraskeva, Christakis A.

    2015-04-01

    The deposition of sparingly soluble salts (scaling) within porous media is a major problem encountered in many industrial and environmental applications. In the oil industry scaling causes severe operational malfunctions and, therefore, increasing the total operating and maintenance cost [1]. The most common types of sparingly soluble salts located in oil fields include carbonate and sulfate salts of calcium, strondium and barium[1,2]. Multiple phase flow and tubing surface properties are some of the factors affecting scale formation [3]. The main purpose of the present work was the investigation of the precipitation mechanisms of calcium carbonate (CaCO3) through in situ mixing of two soluble salt solutions in a flow granular medium, in the presence of water miscible organic fluid (ethylene glycol) or non-miscible organic fluid (n-dodecane). All series of experiments were carried out in a two dimensional porous medium made of Plexiglas. For all solutions used in the experiments, the contact angles with the surface of the porous medium and the interfacial tensions were measured. During the experiments, the calcium carbonate crystal growth was continuously monitored and recorded through an optical microscope equipped with a digital programmed video camera. The snap-shots were taken within specific time intervals and their detailed procession gave information concerning the crystal growth rate and kinetics. The pH of the effluent was measured and fluids samples were collected for calcium analysis using Atomic Absorption Spectroscopy (AAS). In all experiments effluent calcium concentration decreased as a function of time, suggesting that CaCO3 precipitation took place inside the porous medium. Crystals of the precipitated salt were identified using Infrared Spectroscopy (IR) and the morphology of the crystals was examined using Scanning Electron Microscopy (SEM). The induction time for precipitation of CaCO3 crystals in the presence of n-dodecane was significantly

  14. Numerical Simulations of Precipitation Processes, Microphysics, and Microwave Radiative Properties of flood Producing Storms in Mediterranean & Adriatic Basins

    NASA Technical Reports Server (NTRS)

    Smith, Eric A.; Einaudi, Franco (Technical Monitor)

    2001-01-01

    A comprehensive understanding of the meteorological and microphysical nature of Mediterranean storms requires a combination of in situ data analysis, radar data analysis, and satellite data analysis, effectively integrated with numerical modeling studies at various scales. An important aspect of understanding microphysical controls of severe storms, is first understanding the meteorological controls under which a storm has evolved, and then using that information to help characterize the dominant microphysical processes. For hazardous Mediterranean storms, highlighted by the October 5-6, 1998 Friuli flood event in northern Italy, a comprehensive microphysical interpretation requires an understanding of the multiple phases of storm evolution. This involves intense convective development, Sratiform decay, orographic lifting, and sloped frontal lifting processes, as well as the associated vertical motions and thermodynamical instabilities governing physical processes that effect details of the size distributions and fall rates of the various types of hydrometeors found within the storm environment. This talk overviews the microphysical elements of a severe Mediterranean storm in such a context, investigated with the aid of TRMM satellite and other remote sensing measurements, but guided by a nonhydrostatic mesoscale model simulation of the Friuli flood event. The data analysis for this paper was conducted by my research groups at the Global Hydrology and Climate Center in Huntsville, AL and Florida State University in Tallahassee, and in collaboration with Dr. Alberto Mugnai's research group at the Institute of Atmospheric Physics in Rome. The numerical modeling was conducted by Professor Oreg Tripoli and Ms. Giulia Panegrossi at the University of Wisconsin in Madison, using Professor Tripoli's nonhydrostatic modeling system (NMS). This is a scalable, fully nested mesoscale model capable of resolving nonhydrostatic circulations from regional scale down to cloud scale

  15. Pakistan Flooding

    Atmospheric Science Data Center

    2013-04-16

    article title:  Flooding in Pakistan     View Larger Image In late July 2010, flooding caused by heavy monsoon rains began in several regions of Pakistan, ... river is 23 kilometers (14 miles) wide or more in spots, and flooding in much of the surrounding region, particularly in the Larkana ...

  16. On the phase-field modelling of a miscible liquid/liquid boundary.

    PubMed

    Xie, Ruilin; Vorobev, Anatoliy

    2016-02-15

    Mixing of miscible liquids is essential for numerous processes in industry and nature. Mixing, i.e. interpenetration of molecules through the liquid/liquid boundary, occurs via interfacial diffusion. Mixing can also involve externally or internally driven hydrodynamic flows, and can lead to deformation or disintegration of the liquid/liquid boundary. At the moment, the mixing dynamics remains poorly understood. The classical Fick's law, generally accepted for description of the diffusion process, does not explain the experimental observations, in particular, the recent experiments with dissolution of a liquid solute by a liquid solvent within a horizontal capillary (Stevar and Vorobev, 2012). We present the results of the numerical study aimed at development of an advanced model for the dissolution dynamics of liquid/liquid binary mixtures. The model is based on the phase-field (Cahn-Hilliard) approach that is used as a physics-based model for the thermo- and hydrodynamic evolution of binary mixtures. Within this approach, the diffusion flux is defined through the gradient of chemical potential, and, in particular, includes the effect of barodiffusion. The dynamic interfacial stresses at the miscible interface are also taken into account. The simulations showed that such an approach can accurately reproduce the shape of the solute/solvent boundary, and some aspects of the diffusion dynamics. Nevertheless, all experimentally-observed features of the diffusion motion of the solute/solvent boundary, were not reproduced. PMID:26609922

  17. Effective Interactions and Miscibility of Nanoparticles in Multiblock Copolymer Melts

    DOE PAGESBeta

    Banerjee, Debapriya; Schweizer, Kenneth S

    2015-01-01

    The microscopic Polymer Reference Interaction Site Model theory is employed to study, for the first time, the effective interactions, spatial organization, and miscibility of dilute spherical nanoparticles in non-microphase separating, chemically heterogeneous, compositionally symmetric AB multiblock copolymer melts of varying monomer sequence or architecture. The dependence of nanoparticle wettability on copolymer sequence and chemistry results in interparticle potentials-of-mean force that are qualitatively different from homopolymers. An important prediction is the ability to improve nanoparticle dispersion via judicious choice of block length and monomer adsorption-strengths which control both local surface segregation and chain connectivity induced packing constraints and frustration. The degreemore » of dispersion also depends strongly on nanoparticle diameter relative to the block contour length. Small particles in copolymers with longer block lengths experience a more homopolymer-like environment which renders them relatively insensitive to copolymer chemical heterogeneity and hinders dispersion. Larger particles (sufficiently larger than the monomer diameter) in copolymers of relatively short block lengths provide better dispersion than either a homopolymer or random copolymer. The theory also predicts a novel widening of the miscibility window for large particles upon increasing the overall molecular weight of copolymers composed of relatively long blocks. The influence of a positive chi-parameter in the pure copolymer melt is briefly studied. Quantitative application to fullerenes in specific copolymers of experimental interest is performed, and miscibility predictions are made.« less

  18. Regimes of miscible fluid thread formation in microfluidic focusing sections

    NASA Astrophysics Data System (ADS)

    Cubaud, Thomas; Notaro, Sara

    2014-12-01

    We experimentally study the formation and stability of miscible fluid threads made of high-viscosity liquids using hydrodynamic focusing sections. Miscible core annular flows are useful for transporting viscous materials and can be destabilized for enhancing mass transfer. We delineate phase-diagrams of the generation of lubricated threads from low to large viscosity contrasts with various diffusion coefficients. Depending on fluid properties and flow rates of injection, stable microflows are classified into engulfment, thread, and tubing regimes. For low Péclet numbers, we examine thread dynamics when diffusive effects strongly alter basic flow structures and induce new flow configurations, including ultra-diffusive and diffusive instability regimes. Another unstable flow arrangement is investigated for moderate Reynolds numbers where small threads are rapidly destabilized in the inertial flow field of the sheath fluid near the fluid junction. This study provides an overview of stable and unstable flow regimes and their transitions during the formation of miscible viscous fluid filaments in square microchannels.

  19. Effective Interactions and Miscibility of Nanoparticles in Multiblock Copolymer Melts

    SciTech Connect

    Banerjee, Debapriya; Schweizer, Kenneth S

    2015-01-01

    The microscopic Polymer Reference Interaction Site Model theory is employed to study, for the first time, the effective interactions, spatial organization, and miscibility of dilute spherical nanoparticles in non-microphase separating, chemically heterogeneous, compositionally symmetric AB multiblock copolymer melts of varying monomer sequence or architecture. The dependence of nanoparticle wettability on copolymer sequence and chemistry results in interparticle potentials-of-mean force that are qualitatively different from homopolymers. An important prediction is the ability to improve nanoparticle dispersion via judicious choice of block length and monomer adsorption-strengths which control both local surface segregation and chain connectivity induced packing constraints and frustration. The degree of dispersion also depends strongly on nanoparticle diameter relative to the block contour length. Small particles in copolymers with longer block lengths experience a more homopolymer-like environment which renders them relatively insensitive to copolymer chemical heterogeneity and hinders dispersion. Larger particles (sufficiently larger than the monomer diameter) in copolymers of relatively short block lengths provide better dispersion than either a homopolymer or random copolymer. The theory also predicts a novel widening of the miscibility window for large particles upon increasing the overall molecular weight of copolymers composed of relatively long blocks. The influence of a positive chi-parameter in the pure copolymer melt is briefly studied. Quantitative application to fullerenes in specific copolymers of experimental interest is performed, and miscibility predictions are made.

  20. Floodplain biogeochemical processing of floodwaters in the Atchafalaya River Basin during the Mississippi River flood of 2011

    USGS Publications Warehouse

    Scott, Durelle T.; Keim, Richard F.; Edwards, Brandon L.; Jones, C. Nathan; Kroes, Daniel E.

    2014-01-01

    The 2011 flood in the Lower Mississippi resulted in the second highest recorded river flow diverted into the Atchafalaya River Basin (ARB). The higher water levels during the flood peak resulted in high hydrologic connectivity between the Atchafalaya River and floodplain, with up to 50% of the Atchafalaya River water moving off channel. Water quality samples were collected throughout the ARB over the course of the flood event. Significant nitrate (NO3-) reduction (75%) occurred within the floodplain, resulting in a total NO3- reduction of 16.6% over the flood. The floodplain was a small but measurable source of dissolved reactive phosphorus (SRP) and ammonium (NH4+). Collectively, these results from this large flood event suggest that enhancing river-floodplain connectivity through freshwater diversions will reduce NO3- loads to the Gulf of Mexico during large annual floods.

  1. Distillation Column Flooding Predictor

    SciTech Connect

    2002-02-01

    This factsheet describes a research project whose goal is to develop the flooding predictor, an advanced process control strategy, into a universally useable tool that will maximize the separation yield of a distillation column.

  2. Determining CO2 storage potential during miscible CO2 enhanced oil recovery: noble gas and stable isotope tracers

    USGS Publications Warehouse

    Shelton, Jenna L.; McIntosh, Jennifer C.; Hunt, Andrew; Beebe, Thomas L; Parker, Andrew D; Warwick, Peter; Drake, Ronald; John E. McCray

    2016-01-01

    Rising atmospheric carbon dioxide (CO2) concentrations are fueling anthropogenic climate change. Geologic sequestration of anthropogenic CO2 in depleted oil reservoirs is one option for reducing CO2 emissions to the atmosphere while enhancing oil recovery. In order to evaluate the feasibility of using enhanced oil recovery (EOR) sites in the United States for permanent CO2 storage, an active multi-stage miscible CO2 flooding project in the Permian Basin (North Ward Estes Field, near Wickett, Texas) was investigated. In addition, two major natural CO2 reservoirs in the southeastern Paradox Basin (McElmo Dome and Doe Canyon) were also investigated as they provide CO2 for EOR operations in the Permian Basin. Produced gas and water were collected from three different CO2 flooding phases (with different start dates) within the North Ward Estes Field to evaluate possible CO2 storage mechanisms and amounts of total CO2 retention. McElmo Dome and Doe Canyon were sampled for produced gas to determine the noble gas and stable isotope signature of the original injected EOR gas and to confirm the source of this naturally-occurring CO2. As expected, the natural CO2 produced from McElmo Dome and Doe Canyon is a mix of mantle and crustal sources. When comparing CO2 injection and production rates for the CO2 floods in the North Ward Estes Field, it appears that CO2 retention in the reservoir decreased over the course of the three injections, retaining 39%, 49% and 61% of the injected CO2 for the 2008, 2010, and 2013 projects, respectively, characteristic of maturing CO2 miscible flood projects. Noble gas isotopic composition of the injected and produced gas for the flood projects suggest no active fractionation, while δ13CCO2 values suggest no active CO2 dissolution into formation water, or mineralization. CO2 volumes capable of dissolving in residual formation fluids were also estimated along with the potential to store pure-phase supercritical CO2. Using a combination of

  3. Controlling Miscibility in Polyethylene-Polynorbornene Block Copolymers via Side-Group Chemistry

    NASA Astrophysics Data System (ADS)

    Mulhearn, William; Register, Richard

    Block copolymers containing a crystallizable block, such as polyethylene (PE), and an amorphous block with high glass transition temperature (Tg) are an interesting class of materials since the rigid glassy block can improve the mechanical response of the article under strain by reinforcing the crystal fold surface. However, to prepare an easily processable PE-containing block copolymer it is necessary to avoid microphase separation in the melt by selection of amorphous blocks with weak repulsive interactions against PE (low Flory interaction parameter χ or interaction energy density X) . Most such low- χ polymers are chemically similar to PE, such as copolymers of ethylene and a small amount of an α-olefin, and therefore exhibit similarly low glass transition temperatures. This work investigates a series of low- and high-Tg polymers based on substituted norbornene monomers, polymerized via ring-opening metathesis polymerization (ROMP). Hydrogenated polynorbornene derivatives possess a wide range of glass transition temperatures, and miscibility with PE can be readily tuned by the choice of substituents on the monomers (e.g. aromatic vs. aliphatic groups). Two species investigated, hydrogenated poly(cyclohexyl norbornene) and hydrogenated poly(norbornyl norbornene), have high Tg and also remain miscible with polyethylene to high molecular weight. Furthermore, we develop a set of mixing rules to qualitatively predict the solubility behavior of substituted ROMP polynorbornenes as a function of their side-groups.

  4. Miscibility and Morphology of Poly(lactic ACID)/POLY(Β-HYDROXYBUTYRATE) Blends

    NASA Astrophysics Data System (ADS)

    Tri Phuong, Nguyen; Guinault, Alain; Sollogoub, Cyrille

    2011-01-01

    The miscibility and morphology of poly(lactic)acid (PLA)/polyβ-hydroxybutyrate (PHB) prepared by melt blending method were investigated by Fourier transform infrared (FTIR), Differential scanning calorimetry (DSC), melt rheology and scanning electron microscopy (SEM) observations. FTIR and DSC methods present some limits to examine the miscibility state of PLA/PHB blends. This drawback can be overcome with the Cole-Cole method by observing the η" = f(η') curves to confirm the miscibility of semicrystalline PLA/ semicrystalline PHB blends. MEB micrographs of fractured surface of blends were also used to investigate the miscibility of these blends.

  5. Distillation Column Flooding Predictor

    SciTech Connect

    George E. Dzyacky

    2010-11-23

    /vapor traffic that produce increased contact area and lead to substantial increases in separation efficiency – which translates to a 10% increase in energy efficiency on a BTU/bbl basis. The Flooding Predictor™ operates on the principle that between five to sixty minutes in advance of a flooding event, certain column variables experience an oscillation, a pre-flood pattern. The pattern recognition system of the Flooding Predictor™ utilizes the mathematical first derivative of certain column variables to identify the column’s pre-flood pattern(s). This pattern is a very brief, highly repeatable, simultaneous movement among the derivative values of certain column variables. While all column variables experience negligible random noise generated from the natural frequency of the process, subtle pre-flood patterns are revealed among sub-sets of the derivative values of column variables as the column approaches its hydraulic limit. The sub-set of column variables that comprise the pre-flood pattern is identified empirically through in a two-step process. First, 2ndpoint’s proprietary off-line analysis tool is used to mine historical data for pre-flood patterns. Second, the column is flood-tested to fine-tune the pattern recognition for commissioning. Then the Flooding Predictor™ is implemented as closed-loop advanced control strategy on the plant’s distributed control system (DCS), thus automating control of the column at its hydraulic limit.

  6. Theory of the Miscibility of Fullerenes in Random Copolymer Melts

    SciTech Connect

    Dadmun, Mark D; Sumpter, Bobby G; Schweizer, Kenneth; Banerjee, Debapriya

    2013-01-01

    We combine polymer integral equation theory and computational chemistry methods to study the interfacial structure, effective interactions, miscibility and spatial dispersion mechanism of fullerenes dissolved in specific random AB copolymer melts characterized by strong non-covalent electron donor-acceptor interactions with the nanofiller. A statistical mechanical basis is developed for designing random copolymers to optimize fullerene dispersion at intermediate copolymer compositions. Pair correlation calculations reveal a strong sensitivity of interfacial packing near the fullerene to copolymer composition and adsorption energy mismatch. The potential of mean force between fullerenes displays rich trends, often non-monotonic with copolymer composition, reflecting a non-additive competition between direct filler attractions and polymer-mediated bridging and steric stabilization. The spinodal phase diagrams are in qualitative agreement with recent solubility limit experimental observations on three systems, and testable predictions are made for other random copolymers. The distinctive non-monotonic variation of miscibility with copolymer composition is found to be primarily a consequence of composition-dependent, spatially short-range attractions between the A and B monomers with the fullerene. A remarkably rich, polymer-specific temperature dependence of the spinodal diagram is predicted which reflects the thermal sensitivity of spatial correlations which can result in fullerene miscibility either increasing or decreasing with cooling. The calculations are contrasted with a simpler effective homopolymer model and the random structure Flory-Huggins model. The former appears to be qualitatively reasonable but can incur large quantitative errors since it misses preferential packing of monomers near nanoparticles, while the latter appears to fail qualitatively due to its neglect of all spatial correlations.

  7. Study of miscible and immiscible flows in a microchannel using magnetic resonance imaging.

    PubMed

    Akpa, Belinda S; Matthews, Sinéad M; Sederman, Andrew J; Yunus, Kamran; Fisher, Adrian C; Johns, Michael L; Gladden, Lynn F

    2007-08-15

    Magnetic resonance imaging (MRI) is a noninvasive technique that can be used to visualize mixing processes in optically opaque systems in up to three dimensions. Here, MRI has been used for the first time to obtain both cross-sectional velocity and concentration maps of flow through an optically opaque Y-shaped microfluidic sensor. Images of 23 micromx23 microm resolution were obtained for a channel of rectangular cross section (250 micromx500 microm) fed by two square inlets (250 micromx250 microm). Both miscible and immiscible liquid systems have been studied. These include a system in which the coupling of flow and mass transfer has been observed, as the diffusion of the analyte perturbs local hydrodynamics. MRI has been shown to be a versatile tool for the study of mixing processes in a microfluidic system via the multidimensional spatial resolution of flow and mass transfer. PMID:17630718

  8. Instability patterns in a miscible core annular flow

    NASA Astrophysics Data System (ADS)

    D'Olce, Marguerite; Martin, Jerome; Rakotomalala, Nicole; Salin, Dominique; Talon, Laurent

    2006-11-01

    Laboratoire FAST, batiment 502, campus universitaire, 91405 Orsay Cedex (France). Experiments are performed with two miscible fluids of equal density but different viscosities. The fluids are injected co-currently and concentrically into a cylindrical pipe. The so-obtained base state is an axisymmetric parallel flow, for which the ratio of the flow rates of the two fluids monitors the relative amount (and so the radius) of the fluids. Depending on this relative amount and on the total flow rate of the fluids, unstable axisymmetric patterns such as mushrooms and pearls are observed. We delineate the diagram of occurrence of the two patterns and characterize the instabilities.

  9. Miscibility Phase Diagrams of Giant Vesicles Containing Sphingomyelin

    NASA Astrophysics Data System (ADS)

    Veatch, Sarah L.; Keller, Sarah L.

    2005-04-01

    Saturated sphingomyelin (SM) lipids are implicated in lipid rafts in cell plasma membranes. Here we use fluorescence microscopy to observe coexisting liquid domains in vesicles containing SM, an unsaturated phosphatidylcholine lipid (either DOPC or POPC), and cholesterol. We note similar phase behavior in a model membrane mixture without SM (DOPC/DPPC/Chol), but find no micron-scale liquid domains in membranes of POPC/PSM/Chol. We delineate the onset of solid phases below the miscibility transition temperature, and detail indirect evidence for a three-phase coexistence of one solid and two liquid phases.

  10. Interfacial pattern selection in miscible liquids under vibration.

    PubMed

    Gaponenko, Y; Torregrosa, M M; Yasnou, V; Mialdun, A; Shevtsova, V

    2015-11-14

    We explore the peculiar behaviour of an interface between two miscible liquids of similar (but non-identical) viscosities and densities under horizontal vibration with a frequency less than 25 Hz. Significant differences in the structure of the formed patterns were found between microgravity and ground experiments. In a gravity field, a spatially periodic saw-tooth frozen structure is generated in the interface which dissipates at long times. By contrast, under the low gravity conditions of a parabolic flight, the long lived pattern consists of a series of vertical columns of alternating liquids. PMID:26365134

  11. Improving Gas Flooding Efficiency

    SciTech Connect

    Reid Grigg; Robert Svec; Zheng Zeng; Alexander Mikhalin; Yi Lin; Guoqiang Yin; Solomon Ampir; Rashid Kassim

    2008-03-31

    This study focuses on laboratory studies with related analytical and numerical models, as well as work with operators for field tests to enhance our understanding of and capabilities for more efficient enhanced oil recovery (EOR). Much of the work has been performed at reservoir conditions. This includes a bubble chamber and several core flood apparatus developed or modified to measure interfacial tension (IFT), critical micelle concentration (CMC), foam durability, surfactant sorption at reservoir conditions, and pressure and temperature effects on foam systems.Carbon dioxide and N{sub 2} systems have been considered, under both miscible and immiscible conditions. The injection of CO2 into brine-saturated sandstone and carbonate core results in brine saturation reduction in the range of 62 to 82% brine in the tests presented in this paper. In each test, over 90% of the reduction occurred with less than 0.5 PV of CO{sub 2} injected, with very little additional brine production after 0.5 PV of CO{sub 2} injected. Adsorption of all considered surfactant is a significant problem. Most of the effect is reversible, but the amount required for foaming is large in terms of volume and cost for all considered surfactants. Some foams increase resistance to the value beyond what is practical in the reservoir. Sandstone, limestone, and dolomite core samples were tested. Dissolution of reservoir rock and/or cement, especially carbonates, under acid conditions of CO2 injection is a potential problem in CO2 injection into geological formations. Another potential change in reservoir injectivity and productivity will be the precipitation of dissolved carbonates as the brine flows and pressure decreases. The results of this report provide methods for determining surfactant sorption and can be used to aid in the determination of surfactant requirements for reservoir use in a CO{sub 2}-foam flood for mobility control. It also provides data to be used to determine rock permeability

  12. k-t Acceleration in pure phase encode MRI to monitor dynamic flooding processes in rock core plugs

    NASA Astrophysics Data System (ADS)

    Xiao, Dan; Balcom, Bruce J.

    2014-06-01

    Monitoring the pore system in sedimentary rocks with MRI when fluids are introduced is very important in the study of petroleum reservoirs and enhanced oil recovery. However, the lengthy acquisition time of each image, with pure phase encode MRI, limits the temporal resolution. Spatiotemporal correlations can be exploited to undersample the k-t space data. The stacked frames/profiles can be well approximated by an image matrix with rank deficiency, which can be recovered by nonlinear nuclear norm minimization. Sparsity of the x-t image can also be exploited for nonlinear reconstruction. In this work the results of a low rank matrix completion technique were compared with k-t sparse compressed sensing. These methods are demonstrated with one dimensional SPRITE imaging of a Bentheimer rock core plug and SESPI imaging of a Berea rock core plug, but can be easily extended to higher dimensionality and/or other pure phase encode measurements. These ideas will enable higher dimensionality pure phase encode MRI studies of dynamic flooding processes in low magnetic field systems.

  13. k-t acceleration in pure phase encode MRI to monitor dynamic flooding processes in rock core plugs.

    PubMed

    Xiao, Dan; Balcom, Bruce J

    2014-06-01

    Monitoring the pore system in sedimentary rocks with MRI when fluids are introduced is very important in the study of petroleum reservoirs and enhanced oil recovery. However, the lengthy acquisition time of each image, with pure phase encode MRI, limits the temporal resolution. Spatiotemporal correlations can be exploited to undersample the k-t space data. The stacked frames/profiles can be well approximated by an image matrix with rank deficiency, which can be recovered by nonlinear nuclear norm minimization. Sparsity of the x-t image can also be exploited for nonlinear reconstruction. In this work the results of a low rank matrix completion technique were compared with k-t sparse compressed sensing. These methods are demonstrated with one dimensional SPRITE imaging of a Bentheimer rock core plug and SESPI imaging of a Berea rock core plug, but can be easily extended to higher dimensionality and/or other pure phase encode measurements. These ideas will enable higher dimensionality pure phase encode MRI studies of dynamic flooding processes in low magnetic field systems. PMID:24809307

  14. Monitoring and Risk Identification Caused by High Water, Floods and Erosion Processes in Urban Part of Sava Riverbed

    NASA Astrophysics Data System (ADS)

    Oskoruš, D.; Miković, N.; Ljevar, I.

    2012-04-01

    Riverbed erosion and bottom deepening are part of natural fluvial processes in the upper stream of Sava River. The increasing gradient of those changes is interconnected with the level of human influence in the river basin and riverbed as well. In time period of last forty years the consequences of riverbed erosion are become serious as well as dangerous and they threaten the stability of hydro technical structures. The increasing value of flow velocity in riverbed in urban part of river section during high water level, mud and debris flow during the floods as well, is especially dangerous for old bridges. This paper contains result of velocity measurements during high waters taken by Hydrological Service of Republic Croatia, load transport monitoring during such events and cross sections in some vulnerable location. In this paper is given one example of Jakuševac railway bridge in Zagreb, heavily destroyed during high water event on the 30 March 2009., recently reconstructed by "Croatian Railways" company. Keywords: Riverbed erosion, flow velocity, mud and debris flow, risk identification, stability of bridges

  15. Flow and sediment processes in a cutoff meander of the Danube Delta during 100-year recurrent flood

    NASA Astrophysics Data System (ADS)

    Jugaru Tiron, L.; Le Coz, J.; Provansal, M.; Dutu, F.

    2009-04-01

    River training operations, such as meander cutoff, initiated for navigational purposes often lead to dramatic changes in the streamwise profiles (Hooke, 1986, Kesel, 2003; Kiss et al., 2007). Meander correction affects both the hydraulic and morphodynamical behavior of the modified branches that sedimentation occurs in time, while newly built canals usually experience degradation (Jugaru et. al, 2006). This study reports and analyzes new data on the hydrological and sedimentary processes at work during a morphogenic flood in a large modified meander (the Mahmudia meander) of the St. George branch, the southern branch of the Danube Delta. The 100-year recurrent flood that occurred in 2006 offered an exceptional opportunity for scanning different cross sections of the Mahmudia meander system by means of the emerging Doppler profiler (aDcp) technology in order to analyze the impact on sedimentation and dynamic processes in the study area. The Mahmudia study site corresponds to a vast natural meander which was cut off in 1984-1988 by an artificial canal opened to shipping. The meander correction accelerated fluxes through the artificial canal and dramatically enhanced deposition in the former meander. After his formation, the cutoff meander acted as sediment storage locations, essentially removing channel and point bar sediments from the active sediment budget of the main channel (Popa, 1997). During the one-hundred-year recurrent flood in April 2006, bathymetry, flow velocity and discharge data were acquired across several sections of both natural and artificial channels with an acoustic Doppler current profiler (aDcp Workhorse Sentinel 600 kHz, Teledyne RDI) in order to investigate the distribution of the flow and sediment and his impact on sedimentation in a channelized reach and its adjacent cutoff. The contrasting hydro-sedimentary processes at work in both channels and bifurcation/confluence nodal points are analyzed from the measured flux distribution

  16. Evidence for the Cooccurrence of Nitrite-Dependent Anaerobic Ammonium and Methane Oxidation Processes in a Flooded Paddy Field

    PubMed Central

    Shen, Li-dong; Liu, Shuai; Huang, Qian; Lian, Xu; He, Zhan-fei; Geng, Sha; Jin, Ren-cun; He, Yun-feng; Lou, Li-ping; Xu, Xiang-yang; Zheng, Ping

    2014-01-01

    Anaerobic ammonium oxidation (anammox) and nitrite-dependent anaerobic methane oxidation (n-damo) are two of the most recent discoveries in the microbial nitrogen cycle. In the present study, we provide direct evidence for the cooccurrence of the anammox and n-damo processes in a flooded paddy field in southeastern China. Stable isotope experiments showed that the potential anammox rates ranged from 5.6 to 22.7 nmol N2 g−1 (dry weight) day−1 and the potential n-damo rates varied from 0.2 to 2.1 nmol CO2 g−1 (dry weight) day−1 in different layers of soil cores. Quantitative PCR showed that the abundance of anammox bacteria ranged from 1.0 × 105 to 2.0 × 106 copies g−1 (dry weight) in different layers of soil cores and the abundance of n-damo bacteria varied from 3.8 × 105 to 6.1 × 106 copies g−1 (dry weight). Phylogenetic analyses of the recovered 16S rRNA gene sequences showed that anammox bacteria affiliated with “Candidatus Brocadia” and “Candidatus Kuenenia” and n-damo bacteria related to “Candidatus Methylomirabilis oxyfera” were present in the soil cores. It is estimated that a total loss of 50.7 g N m−2 per year could be linked to the anammox process, which is at intermediate levels for the nitrogen flux ranges of aerobic ammonium oxidation and denitrification reported in wetland soils. In addition, it is estimated that a total of 0.14 g CH4 m−2 per year could be oxidized via the n-damo process, while this rate is at the lower end of the aerobic methane oxidation rates reported in wetland soils. PMID:25261523

  17. Evidence for the cooccurrence of nitrite-dependent anaerobic ammonium and methane oxidation processes in a flooded paddy field.

    PubMed

    Shen, Li-Dong; Liu, Shuai; Huang, Qian; Lian, Xu; He, Zhan-Fei; Geng, Sha; Jin, Ren-Cun; He, Yun-Feng; Lou, Li-Ping; Xu, Xiang-Yang; Zheng, Ping; Hu, Bao-Lan

    2014-12-01

    Anaerobic ammonium oxidation (anammox) and nitrite-dependent anaerobic methane oxidation (n-damo) are two of the most recent discoveries in the microbial nitrogen cycle. In the present study, we provide direct evidence for the cooccurrence of the anammox and n-damo processes in a flooded paddy field in southeastern China. Stable isotope experiments showed that the potential anammox rates ranged from 5.6 to 22.7 nmol N2 g(-1) (dry weight) day(-1) and the potential n-damo rates varied from 0.2 to 2.1 nmol CO2 g(-1) (dry weight) day(-1) in different layers of soil cores. Quantitative PCR showed that the abundance of anammox bacteria ranged from 1.0 × 10(5) to 2.0 × 10(6) copies g(-1) (dry weight) in different layers of soil cores and the abundance of n-damo bacteria varied from 3.8 × 10(5) to 6.1 × 10(6) copies g(-1) (dry weight). Phylogenetic analyses of the recovered 16S rRNA gene sequences showed that anammox bacteria affiliated with "Candidatus Brocadia" and "Candidatus Kuenenia" and n-damo bacteria related to "Candidatus Methylomirabilis oxyfera" were present in the soil cores. It is estimated that a total loss of 50.7 g N m(-2) per year could be linked to the anammox process, which is at intermediate levels for the nitrogen flux ranges of aerobic ammonium oxidation and denitrification reported in wetland soils. In addition, it is estimated that a total of 0.14 g CH4 m(-2) per year could be oxidized via the n-damo process, while this rate is at the lower end of the aerobic methane oxidation rates reported in wetland soils. PMID:25261523

  18. Post Waterflood CO{sub 2} Miscible Flood in Light Oil Fluvial-Dominated Deltaic Reservoirs

    SciTech Connect

    1996-04-30

    Texaco terminated the CO{sub 2} purchase agreement with Cardox due to the declining production from the project during 1995. This decision was supported by the DOE and the Exploration and Production Technology Department (EPTD) who developed the model to simulate reservoir performance. Texaco is planning to continue recycling produced CO{sub 2} to recover the remaining 400 MBO from the Marg Area 1 reservoir. Currently one well is remaining on production Kuhn {number_sign}15R after the second producing well Kuhn {number_sign}38 sanded up. Changing the water and CO{sub 2} injection patterns should improve the sweep efficiency and restore production from other existing wells.

  19. FIELD DEMONSTRATION OF CARBON DIOXIDE MISCIBLE FLOODING IN THE LANSING-KANSAS CITY FORMATION, CENTRAL KANSAS

    SciTech Connect

    Alan Byrnes; G. Paul Willhite; Don Green; Martin Dubois; Richard Pancake; Timothy Carr; W. Lynn Watney; John Doveton; Willard Guy; Rodney Reynolds; Rajesh Kunjithaya; Dave Murfin; James Daniels; Niall Avison; Russell Martin; William Flanders; Dave VanderGriend; Eric Mork; Paul Cantrell

    2003-03-31

    Progress is reported for the period from January 1, 2003 to March 31, 2003. A water supply well was permitted, drilled, and completed in the shallow, fresh-water, Dakota Sandstone. The pumphouse has been put in place and the long-term injection equipment is being set-up. Although the short-term injectivity test was cut short by power failure following an ice storm, results indicate the well exhibits sufficient injectivity to proceed with the long-term injectivity test, which will start in the beginning of the second quarter. The CO2 Project No.10 and No.12 wells were reworked and the Lansing-Kansas City (LKC) ''C'' interval in both wells isolated. The CO2 Project No.16 well was drilled deeper, cored in the LKC ''C'' and ''G'' zones, and cased to the ''C'' zone and will be perforated and stimulated in the beginning of second quarter. Initial wireline log analysis and examination of the core indicate that the porosity of the ''C'' zone in this location may be lower than in other parts of the pattern by 3-5 porosity units. Log analysis indicates water saturations are near 60% consistent with predicted residual oil saturation to waterflood modeling. Lower porosities may indicate lower permeability may also be present. Core analysis is being conducted and results will be available in the first week of the second quarter. A draft letter agreement has been presented to FLOCO2 Company for supply of CO2 storage and injection pump equipment.

  20. Suppression of Viscous Fingers in Miscible Hele-Shaw Flow

    NASA Astrophysics Data System (ADS)

    Ramachandran, Radha; Burton, Justin; Nagel, Sidney

    2011-03-01

    The flow of two immiscible fluids between closely-spaced parallel plates can be highly unstable and produce a series of complex fingering patterns when the less viscous injected fluid invades the more viscous one. Air displacing granular material in such a Hele-Shaw geometry shows similar patterns with sharp features consistent with the granular/air surface tension being virtually zero. Here we investigate the flow of two miscible fluids in a radial Hele-Shaw cell, with an inner liquid displacing an outer one of higher viscosity. We use two glycerol- water mixtures so that the viscosity can be tuned by varying the glycerol concentration. We vary the plate spacing and flow rate as well as the fluid viscosites. The non-equilibrium interfacial tension between these two miscible fluids is expected to be nearly zero. However, extrapolating to zero surface tension in the linear theory for Hele-Shaw flow does not describe our results. Specifically, flow becomes stable even when the inner liquid has a much lower viscosity than the outer one. At higher velocity, it is possible to see small amplitude fingering patterns develop.

  1. The Dynamics of Miscible Fluids: A Space Flight Experiment (MIDAS)

    NASA Technical Reports Server (NTRS)

    Maxworthy, T.; Meiburg, E.; Balasubramaniam, R.; Rashidnia, N.; Lauver, R.

    2001-01-01

    We propose a space flight experiment to study the dynamics of miscible interfaces. A less viscous fluid displaces one of higher viscosity within a tube. The two fluids are miscible in all proportions. An intruding "finger" forms that occupies a fraction of the tube. As time progresses diffusion at the interface combined with flow induced straining between the two fluids modifies the concentration and velocity distributions within the whole tube. Also, under such circumstances it has been proposed that the interfacial stresses could depend on the local concentration gradients (Korteweg stresses) and that the divergence of the velocity need not be zero, even though the flow is incompressible. We have obtained reasonable agreement for the tip velocity between numerical simulations (that ignored the Korteweg stress and divergence effects) and physical experiments only at high Peelet Numbers. However at moderate to low Pe agreement was poor. As one possibility we attributed this lack of agreement to the disregard of these effects. We propose a space experiment to measure the finger shape, tip velocity, and the velocity and concentration fields. From intercomparisons between the experiment and the calculations we can then extract values for the coefficients of the Korteweg stress terms and confirm or deny the importance of these stresses.

  2. The Dynamics of Miscible Fluids: A Space Flight Experiment (MIDAS)

    NASA Technical Reports Server (NTRS)

    Maxworthy, T.; Meiburg, E.; Balasubramaniam, R.; Rashidnia, N.; Lauver, R.

    2001-01-01

    We propose a space flight experiment to study the dynamics of miscible interfaces. A less viscous fluid displaces one of higher viscosity within a tube. The two fluids are miscible in all proportions. An intruding "finger" forms that occupies a fraction of the tube. As time progresses diffusion at the interface combined with flow induced straining between the two fluids modifies the concentration and velocity distributions within the whole tube. Also, under such circumstances it has been proposed that the interfacial stresses could depend on the local concentration gradients (Korteweg stresses) and that the divergence of the velocity need not be zero, even though the flow is incompressible. We have obtained reasonable agreement for the tip velocity between numerical simulations (that ignored the Korteweg stress and divergence effects) and physical experiments only at high Peclet Numbers. However at moderate to low Pe agreement was poor. As one possibility we attributed this lack of agreement to the disregard of these effects. We propose a space experiment to measure the finger shape, tip velocity, and the velocity and concentration fields. From intercomparisons between the experiment and the calculations we can then extract values for the coefficients of the Korteweg stress terms and confirm or deny the importance of these stresses.

  3. Qualitative and quantitative methods to determine miscibility in amorphous drug-polymer systems.

    PubMed

    Meng, Fan; Dave, Vivek; Chauhan, Harsh

    2015-09-18

    Amorphous drug-polymer systems or amorphous solid dispersions are commonly used in pharmaceutical industry to enhance the solubility of compounds with poor aqueous solubility. The degree of miscibility between drug and polymer is important both for solubility enhancement as well as for the formation of a physically stable amorphous system. Calculation of solubility parameters, Computational data mining, Tg measurements by DSC and Raman mapping are established traditional methods used to qualitatively detect the drug-polymer miscibility. Calculation of Flory-Huggins interaction parameter, computational analysis of X-Ray Diffraction (XRD) data, solid state Nuclear Magnetic Resonance (NMR) spectroscopy and Atomic Forced Microscopy (AFM) have been recently developed to quantitatively determine the miscibility in amorphous drug-polymer systems. This brief review introduces and compiles these qualitative and quantitative methods employed in the evaluation of drug-polymer miscibility. Combination of these techniques can provide deeper insights into the true miscibility of the drug-polymer systems. PMID:26006307

  4. Influence of surface properties and miscibility upon displacement flow in microchannels

    NASA Astrophysics Data System (ADS)

    Lu, Yu; Nowak, Emilia; Percival, James; Pain, Chris; Simmons, Mark

    2014-11-01

    Microfluidics have potential for a wide range of applications, yet successful operation will depend upon precise understanding of the fluid distribution in multiphase operations, particularly for cleaning of the system. Experiments and numerical studies have been conducted on the displacement process in a single microchannel geometry as a function of fluid dynamics and fluid properties. The microchannel has a near-semicircle cross-section of 205 μm width and 100 μm in depth. Miscible and immiscible fluid pairs (water/glycerol and water/silicon oil respectively) with different viscosity ratios and wettability of the channel walls are examined. Micro-Particle Image Velocimetry (μ-PIV) and Planar Laser Induced Fluorescence (PLIF) are used to obtain velocity fields and interface profile respectively. Flow patterns, interfacial instabilities, displacement efficiency and possible secondary flows are examined. EPSRC Programme Grant, MEMPHIS, EP/K0039761/1.

  5. Investigation of Polymer-Surfactant and Polymer-Drug-Surfactant Miscibility for Solid Dispersion.

    PubMed

    Gumaste, Suhas G; Gupta, Simerdeep Singh; Serajuddin, Abu T M

    2016-09-01

    In a solid dispersion (SD), the drug is generally dispersed either molecularly or in the amorphous state in polymeric carriers, and the addition of a surfactant is often important to ensure drug release from such a system. The objective of this investigation was to screen systematically polymer-surfactant and polymer-drug-surfactant miscibility by using the film casting method. Miscibility of the crystalline solid surfactant, poloxamer 188, with two commonly used amorphous polymeric carriers, Soluplus® and HPMCAS, was first studied. Then, polymer-drug-surfactant miscibility was determined using itraconazole as the model drug, and ternary phase diagrams were constructed. The casted films were examined by DSC, PXRD and polarized light microscopy for any crystallization or phase separation of surfactant, drug or both in freshly prepared films and after exposure to 40°C/75% RH for 7, 14, and 30 days. The miscibility of poloxamer 188 with Soluplus® was <10% w/w, while its miscibility with HPMCAS was at least 30% w/w. Although itraconazole by itself was miscible with Soluplus® up to 40% w/w, the presence of poloxamer drastically reduced its miscibility to <10%. In contrast, poloxamer 188 had minimal impact on HPMCAS-itraconazole miscibility. For example, the phase diagram showed amorphous miscibility of HPMCAS, itraconazole, and poloxamer 188 at 54, 23, and 23% w/w, respectively, even after exposure to 40°C/75% RH for 1 month. Thus, a relatively simple and practical method of screening miscibility of different components and ultimately physical stability of SD is provided. The results also identify the HPMCAS-poloxamer 188 mixture as an optimal surface-active carrier system for SD. PMID:27301752

  6. Alvord (3000-ft Strawn) LPG flood: design and performance evaluation

    SciTech Connect

    Frazier, G.D.; Todd, M.R.

    1982-01-01

    Mitchell Energy Corporation has implemented a LPG-dry gas miscible process in the Alvord (3000 ft Strawn) Unit in Wise County, Texas utilizing the DOE tertiary incentive program. The field had been waterflooded for 14 years and was producing near its economic limit at the time this project was started. This paper presents the results of the reservoir simulation study that was conducted to evaluate pattern configuration and operating alternatives so as to maximize LPG containment and oil recovery performance. Several recommendations resulting from this study were implemented for the project. Based on the model prediction, tertiary oil recovery is expected to be between 100,000 and 130,000 bbls, or about 7 percent of th oil originally in place in the Unit. An evaluation of the project performance to date is presented. In July of 1981 the injection of a 16% HPV slug of propane was completed. Natural gas is being used to drive the propane slug. A peak oil response of 222 BOPD was achieved in August of 1981 and production has since been declining. The observed performance of the flood indicates that the actual tertiary oil recovered will reach the predicted value, although the project life will be longer than expected. The results presented in this paper indicate that, without the DOE incentive program, the economics for this project would still be uncertain at this time.

  7. Assimilation of brightness temperature observations into a process-based hydrological model for flood forecasting applications

    NASA Astrophysics Data System (ADS)

    Weerts, A.; Reggiani, P.; Kwadijk, J.; de Jeu, R.

    2006-12-01

    The aim of this project, sponsored by the Dutch agency for aerospace programmes, is to demonstrate that assimilation of soil moisture data obtained from AMSR-E remotely sensed brightness temperature measurements leads to a reduction of the uncertainty in the stream flow predictions. The method is applied to the 60000 km2 Mosel sub-basin of the river Rhine. Data streams are provided from ground-based telemetric observation networks and from AMSR-E remotely sensed brightness temperature measurements. The satellite soil moisture observations are assimilated into the physcially based representative elementary watershed (REW) model of the Mosel by means of an Ensemble Kalman Filter (EnKF) over a historical simulation time window. The model is then driven in forecast mode with deterministic medium-range weather prediction products. The aim is to demonstrate that the predictive uncertainty on streamflow forecasts due to model deficiencies and errors in the observations can be effectively limited through exploitation of additional information about the system. Remotely sensed brightness temperature observations will be compared with the results of a process-based hydrological modeling platform in which spatial distribution of surface soil moisture and its effect on hydrological response signals can be adequately taken into consideration.

  8. A Lattice Model for Segmental Dynamics of Miscible Polymer Blends

    NASA Astrophysics Data System (ADS)

    Colby, Ralph H.

    2006-03-01

    Thermally-driven concentration fluctuations make local regions (at the scale of monomers) have a wide range of local compositions for weakly interacting miscible blends of long chain polymers. These fluctuations remain important hundreds of degrees from the critical temperature because the entropy (and hence free energy) of mixing is small in polymer mixtures. The connected nature of the chain biases the local composition distribution, making the range of effective compositions surrounding a given monomer extend from the self-composition to environments very rich in that type of monomer. These two polymer physics issues make blends of polymers vastly more interesting than mixtures of small molecules. Time-temperature superposition can fail and motions can persist far below the glass transition temperature of the blend; both of these results are enhanced as the glass transition contrast between the two components increases. A simple lattice model is used to describe the segmental dynamics of miscible polymer blends. Concentration fluctuations and chain connectivity effects are calculated at the scale of the Kuhn length, by considering a central monomer to be surrounded, out to the second shell of monomers, by 24 lattice sites. Including the central monomer, fraction 5/25 = 0.2 of the lattice sites are part of the central monomer's chain (the self-composition) and the other 20 sites are occupied stochastically, while preserving connectivity of all chains. The resulting concentration distributions are mapped onto segmental relaxation time distributions for each blend component using the composition dependence of the glass transition and dynamic scaling. The predicted distributions are compared with experimental dielectric data on miscible polymer blends using three methods: (1) A Debye (single exponential) relaxation of each composition predicts dielectric loss peaks for each blend component which are too narrow because the lattice model ignores density fluctuations

  9. Polymer flooding

    SciTech Connect

    Littmann, W.

    1988-01-01

    This book covers all aspects of polymer flooding, an enhanced oil recovery method using water soluble polymers to increase the viscosity of flood water, for the displacement of crude oil from porous reservoir rocks. Although this method is becoming increasingly important, there is very little literature available for the engineer wishing to embark on such a project. In the past, polymer flooding was mainly the subject of research. The results of this research are spread over a vast number of single publications, making it difficult for someone who has not kept up-to-date with developments during the last 10-15 years to judge the suitability of polymer flooding to a particular field case. This book tries to fill that gap. An indispensable book for reservoir engineers, production engineers and lab. technicians within the petroleum industry.

  10. Serpentine diffusion trajectories and the Ouzo effect in partially miscible ternary liquid mixtures.

    PubMed

    Krishna, Rajamani

    2015-11-01

    This work investigates the transient equilibration process when partially miscible ternary liquid mixtures of two different compositions are brought into contact with each other. Diffusional coupling effects are shown to become increasingly significant as the mixture compositions approach the meta-stable regions of the phase equilibrium diagrams. The proper modelling of coupled diffusion phenomena requires the use of a Fick diffusivity matrix [D], with inclusion of non-zero off-diagonal elements. The primary objective of this article is to develop a simple, robust, procedure for the estimation of the matrix [D], using the Maxwell-Stefan (M-S) formulation as a convenient starting point. In the developed simplified approach, the Fick diffusivity matrix [D] is expressed as the product of a scalar diffusivity and the matrix of thermodynamic correction factors [Γ]. By detailed examination of experimental data for the matrix [D] in a wide variety of ternary mixtures, it is deduced that the major contribution of diffusional coupling arises from the contributions of non-ideal solution thermodynamics, quantified by the matrix of thermodynamic correction factors [Γ]. An important consequence of strong thermodynamic coupling is that equilibration trajectories are serpentine in shape and may exhibit incursions into meta-stable zones opening up the possibility of spontaneous emulsification and the Ouzo effect. If diffusional coupling effects are ignored, the equilibration trajectory is linear in composition space. For a wide variety of partially miscible ternary mixtures, it is demonstrated that the corresponding linear equilibration trajectories do not anticipate the possibility of emulsification. PMID:26421935

  11. Flood Resilient Technological Products

    NASA Astrophysics Data System (ADS)

    Diez Gonzalez, J. J.; Monnot, J. V.; Marquez Paniagua, P.; Pámpanas, P.; Paz Abuín, S.; Prendes, P.; Videra, O.; U. P. M. Smartest Team

    2012-04-01

    As a consequence of the paradigm shift of the EU water policy (Directive 2007/60/EC, EC 2003) from defense to living with flood, floods shall be faced in the future through resilient solutions, seeking to improve the permanence of flood protection, and getting thus beyond traditional temporary and human-relying solutions. But the fact is that nowadays "Flood Resilient (FRe) Building Technological Products" is an undefined concept, and concerned FRe solutions cannot be even easily identified. "FRe Building Technological materials" is a wide term involving a wide and heterogeneous range of solutions. There is an interest in offering an identification and classification of the referred products, since it will be useful for stakeholders and populations at flood risk for adopting the most adequate protections when facing floods. Thus, a previous schematic classification would enable us at least to identify most of them and to figure out autonomous FRe Technological Products categories subject all of them to intense industrial innovative processes. The flood resilience enhancement of a given element requires providing it enough water-repelling capacity, and different flood resilient solutions can be sorted out: barriers, waterproofing and anticorrosive. Barriers are palliative solutions that can be obtained either from traditional materials, or from technological ones, offering their very low weight and high maneuverability. Belonging barriers and waterproofing systems to industrial branches clearly different, from a conceptual point of view, waterproofing material may complement barriers, and even be considered as autonomous barriers in some cases. Actually, they do not only complement barriers by their application to barriers' singular weak points, like anchors, joints, but on the other hand, waterproofing systems can be applied to enhance the flood resilience of new building, as preventive measure. Anticorrosive systems do belong to a clearly different category

  12. Aspects of organic matter transport and processing within Savannah River Plant streams and the Savannah River flood plain swamp

    SciTech Connect

    Hauer, F.R.

    1985-06-01

    The studies were directed toward understanding; (1) the transport dynamics, storage, and retention of organic matter, (2) the processing of leaf material that enters the streams and swamp habitats of the SRP, and (3) how these factors are influenced by current or previous reactor operations at the SRP. Suspended particulate organic matter, benthic organic matter, and in-stream wood were investigated along selected reaches of Steel Creek from April 1983 to April 1984. Concentrations of organic seston ranged from 0.4 to 5.7 mg l/sup -1/. Steel Creek transported significantly higher concentrations of particulate organic matter than did either Meyers Branch or the waters at the swamp site. Seston and dissolved organic matter were investigated on Four Mile Creek, a thermal stream on the SRP, within three different reactor cycles; reactor not operating (cold flow), reactor operating in early portion of cycle (early hot flow), and reactor operating in late portion of cycle (late hot flow). Significantly higher concentrations of particulate organic matter were transported at all study sites during hot flow than during cold flow. Particulate organic matter and dissolved organic matter concentrations were investigated at twelve sampling sites to quantify input and output dynamics of organic matter to the flood plain swamp. Samples were taken biweekly from February 1983 to March 1984. Dissolved organic matter concentrations ranged from 1.3 to 9.9 mg l/sup -1/ and particulate organic matter concentrations ranged from 0.3 to 5.1 mg l/sup -1/. Leaf decomposition of three bottomland tree species was studied at six stream and four swamp sites under various temperature regimes.

  13. The flood event explorer - a web based framework for rapid flood event analysis

    NASA Astrophysics Data System (ADS)

    Schröter, Kai; Lüdtke, Stefan; Kreibich, Heidi; Merz, Bruno

    2015-04-01

    Flood disaster management, recovery and reconstruction planning benefit from rapid evaluations of flood events and expected impacts. The near real time in-depth analysis of flood causes and key drivers for flood impacts requires a close monitoring and documentation of hydro-meteorological and socio-economic factors. Within the CEDIM's Rapid Flood Event Analysis project a flood event analysis system is developed which enables the near real-time evaluation of large scale floods in Germany. The analysis system includes functionalities to compile event related hydro-meteorological data, to evaluate the current flood situation, to assess hazard intensity and to estimate flood damage to residential buildings. A German flood event database is under development, which contains various hydro-meteorological information - in the future also impact information -for all large-scale floods since 1950. This data base comprises data on historic flood events which allow the classification of ongoing floods in terms of triggering processes and pre-conditions, critical controls and drivers for flood losses. The flood event analysis system has been implemented in a database system which automatically retrieves and stores data from more than 100 online discharge gauges on a daily basis. The current discharge observations are evaluated in a long term context in terms of flood frequency analysis. The web-based frontend visualizes the current flood situation in comparison to any past flood from the flood catalogue. The regional flood data base for Germany contains hydro-meteorological data and aggregated severity indices for a set of 76 historic large-scale flood events in Germany. This data base has been used to evaluate the key drivers for the flood in June 2013.

  14. Evolution of flood typology across Europe

    NASA Astrophysics Data System (ADS)

    Hundecha, Yeshewatesfa; Parajka, Juraj; Viglione, Alberto

    2016-04-01

    Following the frequent occurrence of severe flood events in different parts of Europe in the recent past, there has been a rise in interest in understanding the mechanisms by which the different events have been triggered and how they have been evolving over time. This study was carried out to establish the characteristics of observed flood events in the past across Europe in terms of their spatial extent and the processes leading up to the events using a process based hydrological model. To this end, daily discharge data from more than 750 stations of the Global Runoff Data Center were used to identify flood events at the stations based on a threshold method for the period 1961-2010. The identified events at the different stations were further analyzed to determine whether they form the same flood event, thereby delineating the spatial extent of the flood events. The pan-European hydrological model, E-HYPE, which runs at a daily time step, was employed to estimate a set of catchment hydrological and hydro-meteorological state variables that are relevant in the flood generating process for each of the identified spatially delineated flood events. A subsequent clustering of the events based on the simulated state variables, together with the spatial extent of the flood events, was used to identify the flood generating mechanism of each flood event. Four general flood generation mechanisms were identified: long-rain flood, short-rain flood, snowmelt flood, and rain-on-snow flood. A trend analysis was performed to investigate how the frequency of each of the flood types has changed over time. In order to investigate whether there is a regional and seasonal pattern in the dominant flood generating mechanisms, this analysis was performed separately for winter and summer seasons and three different regions of Europe: Northern, Western, and Eastern Europe. The results show a regional difference both in the dominant flood generating mechanism and the corresponding trends.

  15. Role of Conformation in - Interactions and Polymer/Fullerene Miscibility

    SciTech Connect

    Sumpter, Bobby G; Bucknall, David G.; Thio, Yonathan S; Gurun, Bilge; Campbell, Katie

    2011-01-01

    The origin of the miscibility between C60 fullerene and a series of phenylic vinyl polymers has been investigate using a combination of wide-angle x-ray (WAXS) and neutron (WANS) scattering and density functional theory (DFT) computational modeling. The solubility limit of the C60 in the polymers was found to increase non-linearly with increasing phenylic groups in the side-chain from 1 wt% in polystyrene (PS) to 12 wt% in poly(9-vinyl phenanthrene) (P9VPh). The DFT calculations showed that the polymer interacts with the fullerene preferentially with the phenylic groups in these vinyl polymers. However, due to the backbone these phenyl groups are unable to form the energetically favorable T-junction or planar - stacks with the fullerene, and are randomly oriented to the cage. The non-linear increase in solubility is believed to be associated with shape conformity of the three ring phenanthrene to the curvature of the fullerene.

  16. Miscible viscous fingering involving production of gel by chemical reactions

    NASA Astrophysics Data System (ADS)

    Nagatsu, Yuichiro; Hoshino, Kenichi

    2015-11-01

    We have experimentally investigated miscible viscous fingering with chemical reactions producing gel. Here, two systems were employed. In one system, sodium polyacrylate (SPA) solution and aluminum ion (Al3 +) solution were used as the more and less viscous liquids, respectively. In another system, SPA solution and ferric ion (Fe3 +) solution were used as the more and less viscous liquids, respectively. In the case of Al3 +, displacement efficiency was smaller than that in the non-reactive case, whereas in the case of Fe3 +, the displacement efficiency was larger. We consider that the difference in change of the patterns in the two systems will be caused by the difference in the properties of the gels. Therefore, we have measured the rheological properties of the gels by means of a rheometer. We discuss relationship between the VF patterns and the rheological measurement.

  17. Flood Risk and Global Change: Future Prospects

    NASA Astrophysics Data System (ADS)

    Serra-Llobet, A.

    2014-12-01

    Global flood risk is increasing in response to population growth in flood-prone areas, human encroachment into natural flood paths (exacerbating flooding in areas formerly out of harm's way), and climate change (which alters variables driving floods). How will societies respond to and manage flood risk in coming decades? Analysis of flood policy evolution in the EU and US demonstrates that changes occurred in steps, in direct response to disasters. After the flood produced by the collapse of Tous Dam in 1982, Spain initiated a systematic assessment of areas of greatest flood risk and civil protection response. The devastating floods on the Elbe and elsewhere in central Europe in 2002 motivated adoption of the EU Floods Directive (2007), which requires member states to develop systematic flood risk maps (now due) and flood risk management plans (due in 2015). The flooding of New Orleans by Hurricane Katrina in 2005 resulted in a nationwide levee-safety assessment and improvements in communicating risk, but overall less fundamental change in US flood management than manifest in the EU since 2007. In the developing world, large (and increasing) concentrations of populations in low-lying floodplains, deltas, and coasts are increasingly vulnerable, and governments mostly ill-equipped to implement fundamental changes in land use to prevent future increases in exposure, nor to develop responses to the current threats. Even in the developed world, there is surprisingly little research on how well residents of flood-prone lands understand their true risk, especially when they are 'protected' by '100-year' levees. Looking ahead, researchers and decision makers should prioritize improvements in flood risk perception, river-basin-scale assessment of flood runoff processes (under current and future climate and land-use conditions) and flood management alternatives, and bridging the disconnect between national and international floodplain management policies and local land

  18. Mechanistic understanding of miscibility effects on fracture strength of polymer interfaces

    NASA Astrophysics Data System (ADS)

    Gorga, Russell Edward

    This research has provided a fundamental framework based on both experiment and theory to understand the fracture behavior as a function of system miscibility for nonreinforced polymer interfaces. The system chosen for study was polystyrene (PS) and the statistically random copolymer poly (styrene-r-4-bromostyrene) (PBS), where the volume fraction of bromine in the copolymer, f, and the degree of polymerization, N, control the miscibility. The phase behavior of thin film blends of PS and PBS as a function of f and N was studied using atomic force microscopy (AFM) and small angle X-ray scattering (SAXS). Simulations based on the Flory-Huggins theory and the Flory-Huggins interaction parameter, chi, measured from SAXS were used to predict phase diagrams for all the systems studied. Using the phase diagrams, a miscibility map as a function of f, N, and the symmetry of N was developed and showed good agreement with compatibility (measured using AFM). A modified double cantilever beam geometry was employed to measure the Mode I fracture energy (Gc) of PS/PBS interfaces as a function of miscibility. The fracture surfaces were analyzed using scanning electron microscopy and optical microscopy to discern the failure mechanism. The fracture experiments showed that three interdiffusion/fracture regimes exist and that maximizing interfacial strength is based on the competition between gradient-driven and miscibility-limited interdiffusion and can be controlled by optimizing the miscibility of the system. Finally, a new stochastic model, which takes into consideration system miscibility, was developed to calculate Sigmaeff for partially miscible polymer interfaces. Based on this Sigmaeff, a new equation for fracture of non-reinforced systems was postulated which correctly predicts the transition from chain pullout to crazing. This equation incorporates system miscibility via Sigmaeff, the interfacial width, and the average distance between entanglements. As a function of

  19. Discussion of determination and prediction of CO/sub 2/ minimum miscibility pressures

    SciTech Connect

    Holm, L.W.; Josendal, V.A.

    1980-05-01

    This work discusses Yellig and Metcalfe's previous work on the determination and prediction of CO/sub 2/ minimum miscibility pressures (J. Petrol. Technol., Jan 1980 (Pa 274,557)). Improvements in the techniques for determining minimum miscibility pressure in laboratory slim-tube experiments are offered. Data from investigation of several different crude oils are included. The conclusion is that any such prediction technique must take oil composition into consideration, and that this composition must be related to CO/sub 2/ density and minimum miscibility pressure in practices.

  20. Public perception of flood risks, flood forecasting and mitigation

    NASA Astrophysics Data System (ADS)

    Brilly, M.; Polic, M.

    2005-04-01

    A multidisciplinary and integrated approach to the flood mitigation decision making process should provide the best response of society in a flood hazard situation including preparation works and post hazard mitigation. In Slovenia, there is a great lack of data on social aspects and public response to flood mitigation measures and information management. In this paper, two studies of flood perception in the Slovenian town Celje are represented. During its history, Celje was often exposed to floods, the most recent serious floods being in 1990 and in 1998, with a hundred and fifty return period and more than ten year return period, respectively. Two surveys were conducted in 1997 and 2003, with 157 participants from different areas of the town in the first, and 208 in the second study, aiming at finding the general attitude toward the floods. The surveys revealed that floods present a serious threat in the eyes of the inhabitants, and that the perception of threat depends, to a certain degree, on the place of residence. The surveys also highlighted, among the other measures, solidarity and the importance of insurance against floods.

  1. Magnetic resonance imaging analysis on the in-situ mixing zone of CO2 miscible displacement flows in porous media

    NASA Astrophysics Data System (ADS)

    Song, Yongchen; Yang, Wenzhe; Wang, Dayong; Yang, Mingjun; Jiang, Lanlan; Liu, Yu; Zhao, Yuechao; Dou, Binlin; Wang, Zhiguo

    2014-06-01

    The in-situ mixing zone represents dynamic characteristics of CO2 miscible displacement flows, which is important for carbon dioxide enhanced oil recovery (CO2-EOR) projects. However, the migration characteristics of the in-situ mixing zone under reservoir conditions has been neither well studied nor fully understood. The in-situ mixing zone with the flowing mixture of supercritical CO2 and n-decane (nC10) was investigated by using a magnetic resonance imaging apparatus at a reservoir condition of 8.5 MPa and 37.8 °C in porous media. The experimental results showed that the CO2-frontal velocity was larger than the mixing-frontal velocity. The mixing zone length was linearly declined in the miscible displacement process. And the declining rate of the mixing zone length was increased with injection rate. It indicates that the mixing zone length is not constant in a vertically stable CO2 misible displacement and a volume contraction due to phase behavior effects may occur. Then, an error function based on the convection-dispersion equation was fitted with CO2 miscible displacement experiments. The error function was well fitted both at a series of fixed core positions and a series of fixed displacement times. Furthermore, the longitudinal dispersion coefficients (Klx and Klt) and the longitudinal Peclet numbers (Ped and PeL) were quantified from the fitting results. The evolutions of the longitudinal dispersion coefficient were reduced along the displacement time. And the declining rate was increased with injection rate. And with proceeding, the longitudinal dispersion coefficient was tending towards stability and constant. But the evolutions of the longitudinal Peclet numbers were increased along the displacement time. And the increasing rate was increased with injection rate.

  2. Comparative hemolytic activity of undiluted organic water-miscible solvents for intravenous and intra-arterial injection.

    PubMed

    Mottu, F; Stelling, M J; Rüfenacht, D A; Doelker, E

    2001-01-01

    In humans, nonaqueous solvents are administered intravascularly in two kinds of situations. They have been used in subcutaneous or intramuscular pharmaceutical formulations to dissolve water-insoluble drugs. The need for these vehicles had increased in recent years, since the drug development process has yielded many poorly water-soluble drugs. The use of water-miscible nonaqueous solvents in therefore one of the approaches for administering these products as reference solutions useful in formulation bioequivalence studies. The intravascular use of organic solvents has also gained importance owing to a new approach for the treatment of cerebral malformations using precipitating polymers dissolved in water-miscible organic solvents. At present, the solvent most commonly used for the liquid embolics to solubilize the polymers is dimethyl sulfoxide, which exhibits some local and hemodynamic toxicities. In order to find new, less toxic vehicles for pharmaceutical formulations for the intravenous and intra-arterial routes and for embolic materials, 13 water-miscible organic solvents currently used (diluted with water) for pharmaceutical applications, were evaluated in this study. Their hemolytic activity and the morphological changes induced when mixed with blood (1:99, 5:95, 10:90 solvent:blood) were estimated in vitro. From these data, the selected organic solvents could be subdivided into four groups depending on their hemolytic activity: very highly hemolytic solvents (ethyl lactate, dimethyl sulfoxide), highly hemolytic solvents (polyethylene glycol 200, acetone), moderately hemolytic solvents (tetrahydrofurfuryl alcohol, N-methyl-2-pyrrolidone, glycerol formal, ethanol, Solketal, glycofurol) and solvents with low hemolytic activity (propylene glycol, dimethyl isosorbide, diglyme). PMID:11212416

  3. A database on flood and debris-flow processes in alluvial fans: a preliminary analysis aimed at evaluation of the damage

    NASA Astrophysics Data System (ADS)

    Vennari, Carmela; Santangelo, Nicoletta; Santo, Antonio; Parise, Mario

    2015-04-01

    Debris-flow and flood events cause yearly wide damages to buildings and infrastructures, and produce many casualties and fatalities. These processes are very common in Italy, affecting mainly torrential stream basins with different geological and morphological settings: in the Alpine mountain areas they are quite well analysed, whilst much less attention is generally paid in contexts such as those of the Apennines mostly due to the minor frequency of the events. Nevertheless, debris-flows and flood processes occur along many alluvial fans, have greatly contributed to their building up, and are therefore worth to be studied. Along many areas of the Southern Apennines, coalescent alluvial fans are a widespread geomorphic unit, typically located at the foot of steep slopes. In most cases these areas correspond to the more highly urbanised sectors, generally considered to be safer than the bottom valley, as concerns the direct effects from flooding. During intense storms, villages and towns built on alluvial fans may be affected by flooding and/or debris flow processes originated in the above catchment, and rapidly transferred downslope due to the steep slopes and the torrential character of the streams. This creates a very high hazard to the population and is at the origin of the severe and recurrent damage to urban settlements. Starting from the above considerations, we compiled a catalogue of flood and debris-flow events occurred in Campania Region, southern Italy, by consulting very different information sources: national and local newspapers and journals, regional historical archives, scientific literature, internet blogs. More than 350 events, occurred in Campania from 1700 to present, were collected. Information on time of occurrence and location are available for each event, with different level of accuracy, that is typically lower going back to the oldest events for which only the year or the month of occurrence of the event was identified; nevertheless, for

  4. MISCIBILITY, SOLUBILITY, AND VISCOSITY MEASUREMENTS FOR R-236EA WITH POTENTIAL LUBRICANTS

    EPA Science Inventory

    The report gives results of miscibility, solubility, and viscosity measurements of refrigerant R-236ea with three potential lubricants. (NOTE: The data were needed to determine the suitability of refrigerant/lubricant combinations for use in refrigeration systems.) The lubricants...

  5. MISCIBILITY, SOLUBILITY, VISCOSITY, AND DENSITY MEASUREMENTS FOR R-236FA WITH POTENTIAL LUBRICANTS.

    EPA Science Inventory

    Miscibility, solubility, viscosity, and density data are needed to determine the suitability of refrigerant/lubricant combinations for use in refrigeration systems. These property data have been obtained for HFC (hydrofluorocarbon) -236fa and two potential lubricants. The tested ...

  6. Influence of Miscibility of Protein-Sugar Lyophilizates on Their Storage Stability.

    PubMed

    Mensink, Maarten A; Nethercott, Matthew J; Hinrichs, Wouter L J; van der Voort Maarschalk, Kees; Frijlink, Henderik W; Munson, Eric J; Pikal, Michael J

    2016-09-01

    For sugars to act as successful stabilizers of proteins during lyophilization and subsequent storage, they need to have several characteristics. One of them is that they need to be able to form interactions with the protein and for that miscibility is essential. To evaluate the influence of protein-sugar miscibility on protein storage stability, model protein IgG was lyophilized in the presence of various sugars of different molecular weight. By comparing solid-state nuclear magnetic resonance spectroscopy relaxation times of both protein and sugar on two different timescales, i.e., (1)H T1 and (1)H T1ρ, miscibility of the two components was established on a 2-5- and a 20-50-nm length scale, respectively, and related to protein storage stability. Smaller sugars showed better miscibility with IgG, and the tendency of IgG to aggregate during storage was lower for smaller sugars. The largest sugar performed worst and was phase separated on both length scales. Additionally, shorter protein (1)H T1 relaxation times correlated with higher aggregation rates during storage. The enzyme-linked immunosorbent assay (ELISA) assay showed overlapping effects of aggregation and chemical degradation and did not correspond as well with the miscibility. Because of the small scale at which miscibility was determined (2-5 nm) and the size of the protein domains (∼2.5 × 2.5 × 5 nm), the miscibility data give an indirect measure of interaction between protein and sugar. This reduced interaction could be the result of steric hindrance, providing a possible explanation as to why smaller sugars show better miscibility and storage stability with the protein. PMID:27301753

  7. Blend miscibility of cellulose propionate with poly(N-vinyl pyrrolidone-co-methyl methacrylate).

    PubMed

    Sugimura, Kazuki; Teramoto, Yoshikuni; Nishio, Yoshiyuki

    2013-10-15

    The blend miscibility of cellulose propionate (CP) with poly(N-vinyl pyrrolidone-co-methyl methacrylate) (P(VP-co-MMA)) was investigated. The degree of substitution (DS) of CP used ranged from 1.6 to >2.9, and samples for the vinyl polymer component were prepared in a full range of VP:MMA compositions. Through DSC analysis and solid-state (13)C NMR and FT-IR measurements, we revealed that CPs of DS<2.7 were miscible with P(VP-co-MMA)s of VP≥~10mol% on a scale within a few nanometers, in virtue of hydrogen-bonding interactions between CP-hydroxyls and VP-carbonyls. When the DS of CP exceeded 2.7, the miscibility was restricted to the polymer pairs using P(VP-co-MMA)s of VP=ca. 10-40 mol%; the scale of mixing in the blends concerned was somewhat larger (ca. 5-20 nm), however. The appearance of such a "miscibility window" was interpretable as an effect of intramolecular repulsion in the copolymer component. Results of DMA and birefringence measurements indicated that the miscible blending of CP with the vinyl polymer invited synergistic improvements in thermomechanical and optical properties of the respective constituent polymers. Additionally, it was found that the VP:MMA composition range corresponding to the miscibility window was expanded by modification of the CP component into cellulose acetate propionate. PMID:23987378

  8. Phase-field modelling of a miscible system in spinning droplet tensiometer.

    PubMed

    Vorobev, Anatoliy; Boghi, Andrea

    2016-11-15

    The spinning drop tensiometry is used for measurements of surface tension coefficients, especially, when interfaces are characterised by low and ultra-low interfacial stresses. A droplet of lighter liquid is introduced into a rotating capillary that was initially saturated with another heavier liquid. The tube is subject to axial rotation that results in droplet's elongation along the tube's axis. The equilibrium shape of the droplet is used to determine the surface tension coefficient. In this work, the evolution of a slowly miscible droplet introduced into a spinning capillary is investigated. This technique is frequently employed for studies of the dynamics of miscible systems, even despite the fact that a strict equilibrium is never achieved in a mixture of fully miscible liquids. The numerical modelling of a miscible droplet is fulfilled on the basis of the phase-field (Cahn-Hilliard) approach. The numerical results are compared against the experimental data pursuing two objectives: (i) to verify the use of the phase-field approach as a consistent physics-based approach capable of accurate tracking of the short- and long-term evolution of miscible systems, and (ii) to estimate the values of the phenomenological parameters introduced within the phase-field approach, so making this approach a practical tool for modelling of thermohydrodynamic changes in miscible systems within various configurations. PMID:27501043

  9. Determination of the optimum solvent bank size requirement during CO/sub 2/ flooding

    SciTech Connect

    Omole, O.

    1983-01-01

    This laboratory investigation studied the efficiency of water and of nitrogen as CO/sub 2/ slug propellants, determined the optimum CO/sub 2/ slug size required for flooding, and the effect of horizontal permeability variation on oil recovery during CO/sub 2/ miscible flooding in horizontal consolidated Berea sandstone cores. The interaction between carbon dioxide and dolomite rock during CO/sub 2/ flooding in carbonate oil reservoirs was also investigated using dolomite cores. Water was found to be a more efficient CO/sub 2/ slug propellant than nitrogen in the range of pressure and temperature studied. (110/sup 0/F less than or equal to T less than or equal to 120/sup 0/F, 1500 psig less than or equal to flooding pressure less than or equal to 2650 psig). While the efficiency of nitrogen as the CO/sub 2/ slug propellant increased with the flooding pressure, that of water was almost unaffected by the flooding pressure. A 0.3 HPV CO/sub 2/ slug was found to be the optimum solvent bank size required for miscible flooding in the cores used. The total oil recoveries from a core with variable horizontal permeability were a little lower than those from an homogeneous core at similar flooding conditions (crude oil, pressure and temperature). The heterogeneous core contained zones with horizontal permeabilities greater than or equal to the permeability of the homogeneous core. The total oil recoveries were found to be dependent on the flooding temperature - they decreased as the flooding temperature was increased.

  10. Dominant flood generating mechanisms across the United States

    NASA Astrophysics Data System (ADS)

    Berghuijs, Wouter R.; Woods, Ross A.; Hutton, Christopher J.; Sivapalan, M.

    2016-05-01

    River flooding can have severe societal, economic, and environmental consequences. However, limited understanding of the regional differences in flood-generating mechanisms results in poorly understood historical flood trends and uncertain predictions of future flood conditions. Through systematic data analyses of 420 catchments we expose the primary drivers of flooding across the contiguous United States. This is achieved by exploring which flood-generating processes control the seasonality and magnitude of maximum annual flows. The regional patterns of seasonality and interannual variabilities of maximum annual flows are, in general, poorly explained by rainfall characteristics alone. For most catchments soil moisture dependent precipitation excess, snowmelt, and rain-on-snow events are found to be much better predictors of the flooding responses. The continental-scale classification of dominant flood-generating processes we generate here emphasizes the disparity in timing and variability between extreme rainfall and flooding and can assist predictions of flooding and flood risk within the continental U.S.