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Sample records for field west texas

  1. Bob West field: Extending upper Wilcox production in south Texas

    SciTech Connect

    Montgomery, S.L.

    1997-05-01

    Discovered in 1990 near the southern limit of the upper Wilcox gas-producing trend in south Texas, Bob West field is the largest pool to date in this trend, with probable reserves of up to 1 Tcf. The field produces from seven major sandstone {open_quotes}packages,{close_quotes} comprising 27 individual reservoirs and distributed over 3500 productive acres. The sandstones represent either fluvial/deltaic deposits or delta-margin barrier bar and strand-plain sediments. Porosities range up to 20%, but permeabilities are low, commonly less than 1.5 md. Artificial stimulation is therefore required to establish commercial rates of production. Bob West lies on a faulted anticline between two major growth-fault structures, with several stages of structural development evident. Such development has directly affected sandstone thickness. Rates of production are higher at Bob West than at other upper Wilcox fields due to commingling of zones, large-scale fracture treatments, and directional drilling. Discovery at Bob West has significant implications for renewed exploration in this part of the upper Wilcox gas trend.

  2. West Texas State University.

    ERIC Educational Resources Information Center

    Roach, Ed D.

    1988-01-01

    Threats in the external environment, the arrival of a planning-oriented new president, and new regional reaccreditation criteria prompted West Texas State University to undertake a successful strategic planning venture. Leadership must focus strategic planning in a manner that recognizes the decentralized and collegial elements present in higher…

  3. Seismicity of west Texas

    SciTech Connect

    Dumas, D.B.

    1981-01-01

    A four year seismic study has found the Basin and Range province of west Texas and the adjacent area of Mexico to be more seismically active then than heretofore known. A University of Texas five station seismic array around the Marfa Basin has located or detected approximately 800 local and regional earthquakes with S-P times of less than 30 sec. A crustal model for the Basin and Range is derived from natural and artificial sources and contains four layers having velocities of 3.60, 4.93, 6.11, and 6.60 km/sec, respectively, overlying a mantle of 8.37 km/sec. A moderate level of seismic activity has been detected near Van Horn, in the Marfa Basin, and along the Texas-Mexico border between latitudes 30 and 31/sup 0/N. Five earthquake sequences were recorded, two near the Texas-Mexico border and three in the Marfa Basin. Four of these sequences showed quiescent periods in foreshock activity preceding the main shock. On the eastern side of the Marfa Basin a diffuse linear seismic zone may represent an unmapped fault, striking N 50/sup 0/W that coincides with Muehlberger's proposed eastern boundary of Basin and Range faulting. A new epicenter for the Valentine, Texas earthquake of August 16, 1931 has been relocated instrumentally at the northern end of this diffuse zone. Regional and local teleseismic P-wave arrival time anomalies observed for the nearby Gnome underground nuclear explosion of 1961 are used to determine station corrections and thus to locate the new 1931 epicenter at 3.69/sup 0/N, 104.57/sup 0/W. Several estimates of magnitude (m/sub b/) based on intensity data range from 5.6 to 6.4. Fault-plane and composite fault-plane solutions support Muehlberger's hypothesis that the Basin and Range is undergoing extension in a SW-NE direction.

  4. Time Lapse Gravity and Seismic Monitoring of CO2 Injection at the West Hastings Field, Texas

    NASA Astrophysics Data System (ADS)

    Ferguson, J. F.; Richards, T.; Klopping, F.; MacQueen, J.; Hosseini, S. A.

    2015-12-01

    Time lapse or 4D gravity and seismic reflection surveys are being conducted at the West Hastings Field near Houston, Texas to monitor the progress of CO2 injection. This Department of Energy supported CO2 sequestration experiment is conducted in conjunction with a Denbury Onshore, LLC tertiary recovery project. The reservoir is at a depth of 1.8 km in the Oligocene Frio sands and has been produced since the 1930s. Goals are an accounting and mapping of the injected CO2 and to determine if migration occurs along intra-reservoir faults. An integrated interpretation of the geophysical surveys will be made together with well logs and engineering data. Gravity monitoring of water versus gas replacement has been very successful, but liquid phase CO2 monitoring is problematic due to the smaller density contrast with respect to oil and water. This reservoir has a small volume to depth ratio and hence only a small gravity difference signal is expected on the surface. New borehole gravity technology introduced by Micro-g-Lacoste can make gravity measurements at near reservoir depths with a much higher signal to noise ratio. This method has been successfully evaluated on a simulation of the Hastings project. Field operations have been conducted for repeated surface and borehole gravity surveys beginning in 2013. The surface survey of 95 stations covers an area of 3 by 5 km and 22 borehole gravity logs are run in the interval above the Frio formation. 4D seismic reflection surveys are being made at 6 month intervals on the surface and in 3 VSP wells. CO2 injection into the targeted portion of the reservoir only began in early 2015 and monitoring will continue into 2017. To date only the baseline reservoir conditions have been assessed. The overall success of the gravity monitoring will not be determined until 2017.

  5. Water supply and needs for West Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This presentation focused on the water supplies and needs of West Texas, Texas High Plains. Groundwater is the most commonly used water resources on the Texas High Plains, with withdrawals from the Ogallala Aquifer dominating. The saturation thickness of the Ogallala Aquifer in Texas is such that t...

  6. Guadalupian studies in West Texas

    USGS Publications Warehouse

    Grant, R.E.; Wardlaw, B.R.; Rohr, D.M.

    2000-01-01

    Murchison established the Permian System in the Ural Mountains of Russia in 1841. The first North American Permian fossils were discovered by Hall (1856) about 15 years later. The fossils, which were collected in New York State, were initially described as Carboniferous (Hall, 1856) but were subsequently recognized as Permian by Girty (1902). Benjamin F. Shumard (1858), however, was the first to place an unequivocal Permian designation on some North American fossils, which has been collected by his brother George G. Shumard from the Guadalupe Mountains in Texas. A half a century passed before Girty (1908) made known an extensive Guadalupian fauna, although his field work in Texas and his study of this fauna already lead him to propose a Guadalupian "period" (Girty, 1902). Girty's suggestion was accepted only when it was formalized as the Guadalupe Series by Adams et al. (1939). The "Guadalupian fauna" was based upon fossils that Girty collected in 1901 on an expedition headed by Robert T. Hill, a revered figure in Texas geology.

  7. Predicting the natural state of fractured carbonate reservoirs: An Andector Field, West Texas test of a 3-D RTM simulator

    SciTech Connect

    Tuncay, K.; Romer, S.; Ortoleva, P.; Hoak, T.; Sundberg, K.

    1998-12-31

    The power of the reaction, transport, mechanical (RTM) modeling approach is that it directly uses the laws of geochemistry and geophysics to extrapolate fracture and other characteristics from the borehole or surface to the reservoir interior. The objectives of this facet of the project were to refine and test the viability of the basin/reservoir forward modeling approach to address fractured reservoir in E and P problems. The study attempts to resolve the following issues: role of fracturing and timing on present day location and characteristics; clarifying the roles and interplay of flexure dynamics, changing rock rheological properties, fluid pressuring and tectonic/thermal histories on present day reservoir location and characteristics; and test the integrated RTM modeling/geological data approach on a carbonate reservoir. Sedimentary, thermal and tectonic data from Andector Field, West Texas, were used as input to the RTM basin/reservoir simulator to predict its preproduction state. The results were compared with data from producing reservoirs to test the RTM modeling approach. The effects of production on the state of the field are discussed in a companion report. The authors draw the following conclusions: RTM modeling is an important new tool in fractured reservoir E and P analysis; the strong coupling of RTM processes and the geometric and tensorial complexity of fluid flow and stresses require the type of fully coupled, 3-D RTM model for fracture analysis as pioneered in this project; flexure analysis cannot predict key aspects of fractured reservoir location and characteristics; fracture history over the lifetime of a basin is required to understand the timing of petroleum expulsion and migration and the retention properties of putative reservoirs.

  8. Spatial prediction of caves in San Andres dolomite, Yates field, west Texas

    SciTech Connect

    Nosal, E.A.; Carlson, J.L.; Craig, D.H.

    1988-02-01

    Persistent speculation that caves played a key role in the high flow rates of many early wells in the Yates field (203 wells potentialed for more than 10,000 BOPD each, 26 wells for more than 80,000 BOPD each) has raised questions of why the caves exist, how many there are, and how to incorporate them into reservoir management practice. This paper describes the use of probability theory to answer these questions.

  9. Spatial prediction of caves in San Andres Dolomite, Yates field, West Texas

    SciTech Connect

    Nosal, E.A.; Carlson, J.L.; Craig, D.H.

    1988-01-01

    Persistent speculations that caves played a key role in the high flow rates of many early wells in the Yates field (203 wells potentialed for more than 10,000 BOPD each, 26 wells for more than 80,000 BOPD each) has raised questions of why the caves exist, how many there are, and how to incorporate them into reservoir management practice. This paper describes the use of probability theory to answer these questions. Among the geologic factors that contributed to the remarkable early productivity of Yates are zones of karst in the upper San Andres Dolomite, the principle reservoir unit. Hundreds of infill wells drilled after unitization of the field in 1976 have provided ample data on cave numbers and patterns. These data indicate that karstification was produced by dynamic lenses of fresh water beneath a cluster of islands formed when lowering of Late Permian sea level exposed San Andres limestone to rainfall and dissolution. The seemingly random occurrences of caves can be fitted into a geologic framework of systematic karst processes to produce mappable petrophysical parameters. The most important of these predicts, in probabilistic terms, where the caves are located. The contribution of cave porosity to total reservoir porosity can also be estimated. This cave component of porosity can be displayed as a petrophysical log and manipulated in the same way as matrix porosity.

  10. Benchmark West Texas Intermediate crude assayed

    SciTech Connect

    Rhodes, A.K.

    1994-08-15

    The paper gives an assay of West Texas Intermediate, one of the world's market crudes. The price of this crude, known as WTI, is followed by market analysts, investors, traders, and industry managers around the world. WTI price is used as a benchmark for pricing all other US crude oils. The 41[degree] API < 0.34 wt % sulfur crude is gathered in West Texas and moved to Cushing, Okla., for distribution. The WTI posted prices is the price paid for the crude at the wellhead in West Texas and is the true benchmark on which other US crudes are priced. The spot price is the negotiated price for short-term trades of the crude. And the New York Mercantile Exchange, or Nymex, price is a futures price for barrels delivered at Cushing.

  11. Abandoned Texas oil fields

    SciTech Connect

    Not Available

    1980-12-01

    Data for Texas abandoned oil fields were primarily derived from two sources: (1) Texas Railroad Commission (TRRC), and (2) Dwight's ENERGYDATA. For purposes of this report, abandoned oil fields are defined as those fields that had no production during 1977. The TRRC OILMASTER computer tapes were used to identify these abandoned oil fields. The tapes also provided data on formation depth, gravity of oil production, location (both district and county), discovery date, and the cumulative production of the field since its discovery. In all, the computer tapes identified 9211 abandoned fields, most of which had less than 250,000 barrel cumulative production. This report focuses on the 676 abandoned onshore Texas oil fields that had cumulative production of over 250,000 barrels. The Dwight's ENERGYDATA computer tapes provided production histories for approximately two-thirds of the larger fields abandoned in 1966 and thereafter. Fields which ceased production prior to 1966 will show no production history nor abandonment date in this report. The Department of Energy hopes the general availability of these data will catalyze the private sector recovery of this unproduced resource.

  12. Depositional environments and porosity development, Strawn Formation (middle Pennsylvanian), Wagon Wheel and HSA (Penn) fields, west Texas

    SciTech Connect

    McInturff, D.L.; Price, R.C.; Ward, R.F.

    1989-03-01

    The Wagon Wheel and HSA (Penn) fields are located on the western flank of the Central Basin platform within the Permian basin. In this area, both siliciclastic and carbonate depositional systems controlled sedimentation during Strawn time. To the east (HSA Penn field) siliciclastic fanglomerate sedimentation dominated. Several fanglomerate lobes, sourced from the Sand Hills uplift to the east, prograded westward across the platform. Interlobe swamps were common along this strand-line setting. Approximately 3 mi westward (Wagon Wheel Penn field), carbonate bank deposition dominated. Siliciclastic sands and clays commonly are intermixed within these carbonates and represent distal reaches of the siliciclastic progradational lobes. Conglomerates occur more rarely within the carbonate sequence. Carbonates from the upper Strawn (HSA 1392-P well, Wagon Wheel Penn field) demonstrate five shallowing-upward sequences. Each sequence consists of a lower subtidal phylloid algal wackestone which shallows upward into a grainstone shoal deposited above effective wave base. Transgression was rapid and marked by the subtidal phylloid algal wackestone facies overlying the grainstone shoal facies at the top of the previous sequence. Where present, chaetetids punctuate the contact between sequences. Porosity occurs as interparticle voids within the nearshore fanglomerate lobes and as leached biomolds in the grainstone shoals of the carbonate bank. Phylloid algal-rich facies are tight. Porosity is adversely affected by clastic pulses within the grainstone shoal facies and by late-stage ferroan calcite cement.

  13. Paleomagnetic evidence of Tertiary tectonic rotation in west Texas

    SciTech Connect

    Sager, W.W.; Mortera-Gutierrez, C.A. ); Urrutia-Fucugauchi, J. )

    1992-10-01

    Paleomagnetic samples obtained from Rawls Formation (26.9-28.3 Ma) lava flows of Bofecillos volcano in west Texas give a paleomagnetic pole at lat 76.5[degree]N, long 348.0[degree]E ([alpha][sub 95] = 9.4[degree]; N = 20). This pole is displaced significantly from North American reference poles of similar age, implying a clockwise rotation of 21.3[degree] [plus minus] 8.8[degree]. It is also consistent with other paleomagnetic data from west Texas. The authors argue that the discordance is a result of vertical-axis crustal rotation in west Texas caused by shear deformation that was probably related to Basin and Range tectonics.

  14. Paleomagnetic evidence of Tertiary tectonic rotation in west Texas

    NASA Astrophysics Data System (ADS)

    Sager, William W.; Mortera-Gutierrez, Carlos A.; Urrutia-Fucugauchi, Jaime

    1992-10-01

    Paleomagnetic samples obtained from Rawls Formation (26.9-28.3 Ma) lava flows of Bofecillos volcano in west Texas give a paleomagnetic pole at lat 76.5°N, long 348.0°E (α95 = 9.4°; N = 20). This pole is displaced significantly from North American reference poles of similar age, implying a clockwise rotation of 21.3° ± 8.8°. It is also consistent with other paleomagnetic data from west Texas. We argue that the discordance is a result of vertical-axis crustal rotation in west Texas caused by shear deformation that was probably related to Basin and Range tectonics.

  15. West Texas array experiment: Noise and source characterization of short-range infrasound and acoustic signals, along with lab and field evaluation of Intermountain Laboratories infrasound microphones

    NASA Astrophysics Data System (ADS)

    Fisher, Aileen

    The term infrasound describes atmospheric sound waves with frequencies below 20 Hz, while acoustics are classified within the audible range of 20 Hz to 20 kHz. Infrasound and acoustic monitoring in the scientific community is hampered by low signal-to-noise ratios and a limited number of studies on regional and short-range noise and source characterization. The JASON Report (2005) suggests the infrasound community focus on more broad-frequency, observational studies within a tactical distance of 10 km. In keeping with that recommendation, this paper presents a study of regional and short-range atmospheric acoustic and infrasonic noise characterization, at a desert site in West Texas, covering a broad frequency range of 0.2 to 100 Hz. To spatially sample the band, a large number of infrasound gauges was needed. A laboratory instrument analysis is presented of the set of low-cost infrasound sensors used in this study, manufactured by Inter-Mountain Laboratories (IML). Analysis includes spectra, transfer functions and coherences to assess the stability and range of the gauges, and complements additional instrument testing by Sandia National Laboratories. The IMLs documented here have been found reliably coherent from 0.1 to 7 Hz without instrument correction. Corrections were built using corresponding time series from the commercially available and more expensive Chaparral infrasound gauge, so that the corrected IML outputs were able to closely mimic the Chaparral output. Arrays of gauges are needed for atmospheric sound signal processing. Our West Texas experiment consisted of a 1.5 km aperture, 23-gauge infrasound/acoustic array of IMLs, with a compact, 12 m diameter grid-array of rented IMLs at the center. To optimize signal recording, signal-to-noise ratio needs to be quantified with respect to both frequency band and coherence length. The higher-frequency grid array consisted of 25 microphones arranged in a five by five pattern with 3 meter spacing, without

  16. Atmospheric boundary layer evening transitions over West Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A systemic analysis of the atmospheric boundary layer behavior during some evening transitions over West Texas was done using the data from an extensive array of instruments which included small and large aperture scintillometers, net radiometers, and meteorological stations. The analysis also comp...

  17. Enterobacteriaceae isolated from iguanid lizards of west-central Texas.

    PubMed Central

    Mathewson, J J

    1979-01-01

    The prevalence of members of the family Enterobacteriaceae in the intestines of seven species of iguanid lizards native to west-central Texas was determined. Of the 67 lizard specimens examined, 48.7% were infected with Salmonella and 9% were infected with Salmonella arizonae. Two lizard species (Sceloporus olivaceus and Crotaphytus collaris) were shown to have a 100% prevalence of Salmonella. PMID:533273

  18. West Nile virus infection in killer whale, Texas, USA, 2007.

    PubMed

    St Leger, Judy; Wu, Guang; Anderson, Mark; Dalton, Les; Nilson, Erika; Wang, David

    2011-08-01

    In 2007, nonsuppurative encephalitis was identified in a killer whale at a Texas, USA, marine park. Panviral DNA microarray of brain tissue suggested West Nile virus (WNV); WNV was confirmed by reverse transcription PCR and sequencing. Immunohistochemistry demonstrated WNV antigen within neurons. WNV should be considered in cases of encephalitis in cetaceans. PMID:21801643

  19. Two-dimensional resistivity investigation along West Fork Trinity River, Naval Air Station-Joint Reserve Base, Carswell Field, Fort Worth, Texas, October 2004

    USGS Publications Warehouse

    Shah, Sachin D.; Stanton, Gregory P.

    2006-01-01

    Naval Air Station-Joint Reserve Base Carswell Field (NAS-JRB) at Fort Worth, Tex., constitutes a government-owned, contractor-operated facility that has been in operation since 1942. Contaminants, primarily volatile organic compounds and metals, have entered the ground-water-flow system through leakage from waste-disposal sites and manufacturing processes. Ground water flows from west to east toward the West Fork Trinity River. During October 2004, the U.S. Geological Survey conducted a two-dimensional (2D) resistivity investigation at a site along the West Fork Trinity River at the eastern boundary of NAS-JRB to characterize the distribution of subsurface resistivity. Five 2D resistivity profiles were collected, which ranged from 500 to 750 feet long and extended to a depth of 25 feet. The Goodland Limestone and the underlying Walnut Formation form a confining unit that underlies the alluvial aquifer. The top of this confining unit is the top of bedrock at NAS-JRB. The bedrock confining unit is the zone of interest because of the potential for contaminated ground water to enter the West Fork Trinity River through saturated bedrock. The study involved a capacitively-coupled resistivity survey and inverse modeling to obtain true or actual resistivity from apparent resistivity. The apparent resistivity was processed using an inverse modeling software program. The results of this program were used to generate distributions (images) of actual resistivity referred to as inverted sections or profiles. The images along the five profiles show a wide range of resistivity values. The two profiles nearest the West Fork Trinity River generally showed less resistivity than the three other profiles.

  20. Abandoned oil fields of Texas Gulf Coast

    SciTech Connect

    Dutton, S.P.

    1984-04-01

    One nonconventional oil target in Texas is the oil that remains in abandoned fields, defined as those fields that had no oil or gas production in 1977 and 1982. This target includes oil that has not been tapped by conventional field development because of reservoir heterogeneity and oil in reservoirs that have not been subjected to any secondary or tertiary recovery efforts. A total of 138 abandoned oil fields having individual cumulative production greater than 500,000 bbl are located in the Texas Gulf Coast (railroad Commission of Texas Districts 2, 3, and 4). These 138 onshore fields produced 276 million barrels of oil before being abandoned. Nongiant fields in the Texas Gulf Coast average about 40% ultimate recovery, so these fields probably originally contained about 700 million bbl of oil in place. Therefore, about 424 million bbl of oil remain unrecovered. Reservoirs in these abandoned fields are Tertiary sandstones. The 44 abandoned fields in the upper Texas Gulf Coast (District 3) produced from a wide range of plays; those plays with the largest number of abandoned fields are Yegua and Frio deep-seated domes, Eocene deltaic sandstone, and Frio barrier/strand-plain sandstone. The 19 abandoned fields in the middle Texas Gulf Coast (District 2) produced mainly from Wilcox and Frio fluvial/deltaic sandstones and from Frio and Jackson-Yegua barrier/strand-plain sandstones. The lower Texas Gulf Coast (District 4) contains 75 abandoned fields that produced from Frio fluvial/deltaic and barrier/strand-plain sandstones and from Jackson-Yegua barrier/strand-plain sandstones.

  1. Crustal deformation and seismic measurements in the region of McDonald Observatory, West Texas. [Texas and Northern Chihuahua, Mexico

    NASA Technical Reports Server (NTRS)

    Dorman, H. J.

    1981-01-01

    The arrival times of regional and local earthquakes and located earthquakes in the Basin and Range province of Texas and in the adjacent areas of Chihuahua, Mexico from January 1976 to August 1980 at the UT'NASA seismic array are summarized. The August 1931 Texas earthquake is reevaluated and the seismicity and crustal structure of West Texas is examined. A table of seismic stations is included.

  2. 3 CFR 8963 - Proclamation 8963 of April 24, 2013. Honoring the Victims of the Explosion in West, Texas

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Victims of the Explosion in West, Texas 8963 Proclamation 8963 Presidential Documents Proclamations Proclamation 8963 of April 24, 2013 Proc. 8963 Honoring the Victims of the Explosion in West, TexasBy the... perished in the explosion in West, Texas, on April 17, 2013, I hereby order, by the authority vested in...

  3. Multivariable control system installed at ARCO west Texas gas plant

    SciTech Connect

    Chou, K. ); Clay, R.M. ); Gamez, J.P. ); Berkowitz, P.N.; Papadopoulos, M.N. )

    1992-11-16

    This paper reports that a PC-based, multivariable process control (MVC) system was installed last year at an ARCO Oil and Gas Co. gas plant in West Texas. This gas-processing application was developed under sponsorship of the Gas Research Institute. The system was installed, tuned, and on-line within 2 weeks and fully verified in closed loop service by operations in 8 weeks. Four more gas processing installations are currently under way. The general and main objective of the MVC control system is to achieve continuous optimum operation of a process unit through on-line prediction and control of setpoints for the key process variables in the unit. specifically, the objective is to achieve this operation, especially under constantly changing conditions, with reliable solutions requiring minimal operator intervention, customization, or update effort upon each plant change. MVC was developed by continental Controls Inc. (CCI), Houston.

  4. Field evaluation of Bemisia parasitoids in Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two methods were employed to assess the potential of candidate parasitoid species/strains to parasitize B. tabaci under field conditions in Texas. Sleeve cage evaluations were conducted in kale, cantaloupe melons, and cotton in 1994–1995. In kale, the highest parasitism rates were observed for two s...

  5. Analysis of the Wellbore Seal at Well 49-6 in the SACROC CO2 Enhanced Oil Recovery Field, West Texas

    NASA Astrophysics Data System (ADS)

    Carey, J. W.; Wigand, M.; Chipera, S.; Woldegabriel, G.; Pawar, R.; Lichtner, P. C.; Wehner, S.; Raines, M.; Guthrie, G. D.

    2005-12-01

    Long-term integrity of wellbore cements is one of the major concerns for geologic sequestration of CO2. This paper presents analyses of cement core recovered from a well used in a long-term CO2 enhanced oil recovery operation. A sidetrack system was used to obtain core from a 55 year-old well with 30 years of CO2 exposure as both an injector and a producer at the SACROC unit (Permian Basin, Texas). The mineralogy, chemistry, and hydrologic properties were evaluated for evidence of degradation by CO2. The recovered samples were located ~ 3 m above the contact with the reservoir. The recovered cement had permeabilities in the milliDarcy range and thus retained its capacity to prevent significant flow of CO2. There was evidence for CO2 migration along the casing-cement and cement-shale interfaces. The casing interface had a 1-2 mm thick rind of calcite-aragonite-halite. The CO2 producing this rind may have traveled up the casing wall or may have infiltrated through the casing threads. The cement in contact with the shale (within 1 cm) was heavily carbonated to an assemblage of calcite, aragonite, vaterite and amorphous alumino-silica residue and was transformed to a distinctive orange color. The heavily carbonated region is separated from less altered cement by a narrow, dense zone of silica and carbonate deposition. The CO2 for this carbonation process migrated from the cement-shale interface where the presence of shale fragments (wall cake) may have provided a fluid pathway. The carbonation reaction was associated with only small changes in the original cement chemistry including an increase in Na2O and decrease in CaO and MgO with a slight enrichment in SiO2. The carbonated zone also has a distinct carbon and oxygen stable isotope signature. Although the observed carbonation was intense, the measured hydrologic properties of the carbonated zone were not significantly different from those of relatively unaltered cement in adjacent parts of the core. Textural

  6. Evaluating airborne hyperspectral imagery for mapping saltcedar infestations in west Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Rio Grande of west Texas contains by far the largest infestation of saltcedar (Tamarix spp.) in Texas. The objective of this study was to evaluate airborne hyperspectral imagery and different classification techniques for mapping saltcedar infestations. Hyperspectral imagery with 102 usable band...

  7. Using airborne hyperspectral imagery for mapping saltcedar infestations in west Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Rio Grande of west Texas contains, by far, the largest infestation of saltcedar (Tamarix spp.) in Texas. The objective of this study was to evaluate airborne hyperspectral imagery and different classification techniques for mapping saltcedar infestations. Hyperspectral imagery with 102 usable ba...

  8. Nature of basalt-deep crust interaction in the petrogenesis of a potassium-rich, silicic-dominated eruptive system, Davis Mountain volcanic field, west Texas

    SciTech Connect

    Ward, R.L.; Walker, J.A. . Dept. of Geology)

    1993-04-01

    The Davis Mountain volcanic field (DMVF) is one of several silicic-dominated eruptive centers that constitute the bulk of the Trans Pecos volcanic province (TPVP). New major-, trace element, and Pb-O isotope data on local granulite-facies xenoliths and the DMVF are used in evaluating the extent of basalt-deep crust interaction to produce voluminous silicic lavas and -ignimbrites. The DMVF (39.3--35.4 Ma) is a high-K, alkali basalt-potassic trachybasalt-shoshonite-latite-trachyte-rhyolite volcanoplutonic series with the evolved members being silica-saturated. DMF silicic rocks are characterized by high concentrations of Rb, Th, U, and K, low-[sup 18]O and have a broad range in Pb isotopes. These characteristics are inconsistent with an origin by partial melting of a Rb-Th-U depleted, unradiogenic Pb granulitic deep crust. However, distinctly different Pb isotope compositions between mafic and silicic rocks preclude an origin by fractional crystallization alone. Multistage-AFC involving a mantle-source, various proportions of OL-CPX-PLAG-KSPAR-MAG-AP-BIO-QTZ-aenigmatite-ZR differentiation, limited (<10%) amounts of deep and upper crustal contamination, and mixing between mafic and silicic magmas can satisfactorily account for the observed chemical and isotopic variation in the DMVF.

  9. Primary Disaster Field Office (DFO), Lufkin, Texas

    NASA Technical Reports Server (NTRS)

    Wetherbee, James D.

    2005-01-01

    On February 1, 2003, the Space Shuttle Columbia broke apart during atmospheric re-entry on mission STS-107; the complexity of such an event cannot be underestimated. The Lufkin Disaster Field Office (DFO) served as the primary DFO for all operations, including staging assets and deploying field teams for search, recovery and security. There were many organizations that had operational experience with disaster recovery. Offers to help came from many groups including the White House Liaison Office, the Department of Defense (DOD), branches of local, state and federal government, the Federal Bureau of Investigation (FBI), the Federal Emergency Management Agency (FEMA), the Environmental Protection Agency (EPA), state police, fire departments, the Texas Forestry Service, the Texas Army National Guard, medical groups, various rescue forces, contractor companies, the Salvation Army, local businesses, and citizens of our country and especially East Texas. The challenge was to know how much help to accept and how to efficiently incorporate their valuable assistance into a comprehensive and cohesive operational plan. There were more than 2,000 people involved with search and recovery.

  10. Project FUTURE: Opening Doors to Diverse West Texas Teachers

    ERIC Educational Resources Information Center

    Stevens, Tara; Agnello, Mary Frances; Ramirez, Janie; Marbley, Aretha; Hamman, Doug

    2007-01-01

    Project FUTURE is one component of a multifaceted approach in the Northwest Texas region to target Hispanic and African-American youth, encouraging them to go through school with a desire to complete education programs leading to professional credentialing in teaching. Project FUTURE inspires students to believe that they can attend Texas Tech…

  11. Space Radar Image of West Texas - SAR scan

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This radar image of the Midland/Odessa region of West Texas, demonstrates an experimental technique, called ScanSAR, that allows scientists to rapidly image large areas of the Earth's surface. The large image covers an area 245 kilometers by 225 kilometers (152 miles by 139 miles). It was obtained by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) flying aboard the space shuttle Endeavour on October 5, 1994. The smaller inset image is a standard SIR-C image showing a portion of the same area, 100 kilometers by 57 kilometers (62 miles by 35 miles) and was taken during the first flight of SIR-C on April 14, 1994. The bright spots on the right side of the image are the cities of Odessa (left) and Midland (right), Texas. The Pecos River runs from the top center to the bottom center of the image. Along the left side of the image are, from top to bottom, parts of the Guadalupe, Davis and Santiago Mountains. North is toward the upper right. Unlike conventional radar imaging, in which a radar continuously illuminates a single ground swath as the space shuttle passes over the terrain, a Scansar radar illuminates several adjacent ground swaths almost simultaneously, by 'scanning' the radar beam across a large area in a rapid sequence. The adjacent swaths, typically about 50 km (31 miles) wide, are then merged during ground processing to produce a single large scene. Illumination for this L-band scene is from the top of the image. The beams were scanned from the top of the scene to the bottom, as the shuttle flew from left to right. This scene was acquired in about 30 seconds. A normal SIR-C image is acquired in about 13 seconds. The ScanSAR mode will likely be used on future radar sensors to construct regional and possibly global radar images and topographic maps. The ScanSAR processor is being designed for 1996 implementation at NASA's Alaska SAR Facility, located at the University of Alaska Fairbanks, and will produce digital images from the

  12. Lower and middle Guadalupian shelf carbonates, eastern margin of Central Basin platform, Permian basin, west Texas

    SciTech Connect

    Ward, R.F.; Chalcraft, R.G.

    1988-01-01

    Lower and middle Guadalupian shelf carbonates serve as the reservoir for a nearly continuous band of oil fields extending 100 mi along the eastern margin of the Central Basin platform of west Texas. Approximately 5 billion bbl of oil have been produced from stratigraphic-structural traps within the Upper Permian (Gaudalupian Series) dolomites of the San Andrea and Grayburg Formations in Upton, Crane, Ector, Pecos, and Andrews Counties, Texas. The San Andrea and Grayburg Formations are cyclical shallowing-upward carbonate sequences of open shelf through sabkha facies whose depositional strike parallels the eastern margin of the Central Basin platform. Porosity and permeability of reservoir rock are governed by diagenetic processes such as dolomitization, anhydrite porosity occlusion, leaching, silicification, and authigenic clay formation. Self sediments are primarily burrowed wackestones and packstones that locally contain pelletal, skeletal, and ooid grainstones. Typical subtidal shelf sediments are capped by algal-laminated dolomite, nodular anhydritic dolomite, and bedded anhydrite. The fauna is normally sparse and dominated by foraminifera and algae. Less common faunal components include pelecypods, crinoids, sponges, Bryozoa, brachiopods, gastropods, and coral that are associated with the development of small scattered patch reefs. Lowering the sea level during the early Guadalpian initiated basinward progradation of San Andres carbonate facies with hydrocarbon reservoirs best developed in shallow self fusulinid wackestones to packstone and oolitic grainstone. Reservoir dolomites of the Grayburg formation are present east of San Andres fields with optimal reservoir properties occurring near the San Andreas outer shelf margin.

  13. Stratigraphy and correlation of Upper Triassic strata between west Texas and eastern New Mexico

    SciTech Connect

    Lucas, S.G. ); Anderson, O.J. )

    1992-04-01

    Lithostratigraphy and vertebrate biochronology allow precise correlation of Upper Triassic strata between west Texas and eastern New Mexico. Upper Triassic strata are well exposed in west Texas from Oldham to Scurry counties, and are assigned to the Dockum Formation of the Chinle Group. Fossil vertebrates from the Camp Springs and Tecovas Members are of late Carnian age, whereas those from the Copper Member are of early Norian age. Upper Triassic strata in east-central New Mexico, across the Llano Estacado from the west Texas outcrops, correlate as follows: Camper Springs = lower Santa Rose; Tecovas = upper Santa Rosa/Garita Creek; Trujillo = Trujillo ('Cuervo'); Cooper = lower Bull Canyon. Upper Triassic strata in southeastern New Mexico and in Howard and adjacent counties in Texas are the lower Santa Rosa/Camper Springs overlain by mudstones and sandstones that contain late Carnian vertebrates and are informally termed upper member of Dockum Formation. Available data refute several long-held ideas about the Upper Triassic of west Texas. These data demonstrate that: (1) there is a pervasive unconformity at the base of the Dockum Formation that represents much of Triassic time; (2) the Trujillo Member is not correlative with the Santa Rosa of eastern New Mexico: Trujillo is a medial Dockum unit, whereas Santa Rosa is at the base of the Upper Triassic section; (3) very little Dockum mudrock was deposited in lakes; and (4) Dockum rivers flowed almost exclusively to the north, northwest, and west, so there was no closed depositional basin in west Texas during the Late Triassic.

  14. 77 FR 30522 - Sunoco Pipeline L.P., West Texas Gulf Pipe Line Company, Mobil Pipe Line Company; Notice of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-23

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Sunoco Pipeline L.P., West Texas Gulf Pipe Line Company, Mobil Pipe Line... Pipeline L.P., West Texas Gulf Pipe Line Company, and Mobil Pipe Line Company (collectively,...

  15. Application of advanced reservoir characterization, simulation and production optimization strategies to maximize recovery in slope and basin clastic reservoirs, West Texas (Delaware Basin). Annual report

    SciTech Connect

    Dutton, S.P.; Asquith, G.B.; Barton, M.D.; Cole, A.G.; Gogas, J.; Malik, M.A.; Clift, S.J.; Guzman, J.I.

    1997-11-01

    The objective of this project is to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost-effective way to recover a higher percentage of the original oil in place through strategic placement of infill wells and geologically based field development. This project involves reservoir characterization of two Late Permian slope and basin clastic reservoirs in the Delaware Basin, West Texas, followed by a field demonstration in one of the fields. The fields being investigated are Geraldine Ford and Ford West fields in Reeves and Culberson Counties, Texas. Project objectives are divided into two major phases, reservoir characterization and implementation. The objectives of the reservoir characterization phase of the project were to provide a detailed understanding of the architecture and heterogeneity of the two fields, the Ford Geraldine unit and Ford West field. Reservoir characterization utilized 3-D seismic data, high-resolution sequence stratigraphy, subsurface field studies, outcrop characterization, and other techniques. Once reservoir characterized was completed, a pilot area of approximately 1 mi{sup 2} at the northern end of the Ford Geraldine unit was chosen for reservoir simulation. This report summarizes the results of the second year of reservoir characterization.

  16. Oldest termite nest from the Upper Cretaceous of west Texas

    NASA Astrophysics Data System (ADS)

    Rohr, David M.; Boucot, A. J.; Miller, John; Abbott, Maxine

    1986-01-01

    Wood borings and insect frass from the Upper Cretaceous of Texas are interpreted to be the oldest known termite nest, the oldest known termite fecal pellets, and one of the few examples of trace-fossil evidence of social behavior in insects. It illustrates a form of behavioral fixity insofar as coprolite form, feeding habits, and substrate are concerned. *Deceased

  17. Karst-controlled reservoir heterogeneity in Ellenburger group carbonates of west Texas: Reply

    SciTech Connect

    Kerans, C. )

    1990-07-01

    A reply to a comment made on Kerans' paper (AAGP Bull. 1988) by S.J. Mazzullo is presented. The author takes exception that Mazzullo's contention that he left out important types of hydrocarbon reservoirs in the Permian basin of west Texas and points out that his original intention was to model karst-controlled reservoir rocks only.

  18. Preliminary results of dust emission data from Yellow Lake Playa, West Texas, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We investigated the relationship between groundwater and dust emission rates at Yellow Lake, a saline “wet” playa in West Texas with a long history of wind erosion. Deflation of the playa surface has generated lunettes composed of silt-clay aggregates and gypsum. Saltation sensors indicate that most...

  19. AN ANALYSIS OF HIGH SCHOOL VOCATIONAL AGRICULTURE FROM EVALUATIONS OF GRADUATES IN WEST TEXAS.

    ERIC Educational Resources Information Center

    EGGENBERGER, ULRICH LEWIS

    A STUDY OF THE 1953, 1954, AND 1955 WEST TEXAS HIGH SCHOOL GRADUATES WHO HAD COMPLETED 1 OR MORE YEARS OF VOCATIONAL AGRICULTURE WAS CONDUCTED TO (1) DETERMINE PRESENT OCCUPATIONAL STATUS, (2) DETERMINE FACTORS RELATED TO OCCUPATIONAL CHOICE, (3) EVALUATE HIGH SCHOOL COURSES AND VOCATIONAL AGRICULTURE PROGRAMS AS RELATED TO OCCUPATIONS, AND (4)…

  20. Geomorphic and hydrologic controls of dust emissions during drought from Yellow Lake playa, West Texas, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Research on the factors that control dust emissions from playas has revealed a number of complex geomorphic and hydrologic factors, yet there are few measurements of dust emissions from playas during drought or low-emission seasons. Deflation of Yellow Lake, a saline playa in West Texas, produces sa...

  1. West Nile Virus Infection among the Homeless, Houston, Texas1

    PubMed Central

    Meyer, Tamra E.; Bull, Lara M.; Holmes, Kelly Cain; Pascua, Rhia F.; Travassos da Rosa, Amelia; Gutierrez, Christian R.; Corbin, Tracie; Woodward, Jennifer L.; Taylor, Jeffrey P.; Tesh, Robert B.

    2007-01-01

    Among 397 homeless participants studied, the overall West Nile virus (WNV) seroprevalence was 6.8%. Risk factors for WNV infection included being homeless >1 year, spending >6 hours outside daily, regularly taking mosquito precautions, and current marijuana use. Public health interventions need to be directed toward this high-risk population. PMID:18257995

  2. Origin of reservoir compartmentalization in Lower Ordovician Karstic Dolostones, Ellenburger Group, West Texas

    SciTech Connect

    Kerans, C.

    1988-01-01

    Ellenburger Group reservoirs constitute a major play in the Permian basin of west Texas, with over 1.4 billion bbl cumulative production through 1985. These reservoirs typically have been developed by assuming homogeneous fracture-related pore system. Examination of core, log, and production data demonstrates that most Ellenburger reservoirs are characterized by pronounced vertical and lateral heterogeneities created by post-Ellenburger karst development. Vertical reservoir compartmentalization in the Ellenburger evolved from development of a laterally extensive cave system between 100 and 300 ft beneath the original land surface. Caves were filled by relatively impermeable siliciclastics from the overlying Simpson Group, effectively isolating permeable cave-roof breccias (uppermost Ellenburger) from collapse breccias deposited on cave floors prior to shale infill. Lateral compartmentalization of Ellenburger reservoirs originated by localized collapse of the cave system both during karst formation and after burial. In the Shafter Lake field, lateral compartmentalization is the result of a 200-ft vertical collapse during deposition of Simpson Group sands. Abrupt lateral discontinuities in the Big Lake and Glasco fields may represent similar collapse-related features, such as are spectacularly displayed in Ellenburger-equivalent outcrops of the Franklin Mountains. An estimated 750 million bbl of remaining mobile oil, in addition to conventional reserves, occurs in this mature but complexly compartmentalized play. Considering this paleokarst model will aid in further exploitation of Ellenburger reservoirs.

  3. Currents and water characteristics around the West Flower Garden Bank. [West Flower Garden Bank, coral reef, Texas continental shelf

    SciTech Connect

    Horne, D.J.

    1986-01-01

    The West Flower Garden Bank is a coral reef on the Texas Continental shelf. The corals on the bank are vulnerable to sediment contamination and to excess turbidity in the overlying water column. Concern for the environmental impact on this and other banks in the region exposed to nearby hydrocarbon production prompted the Bureau of Land Management to fund a data collection effort on the Texas/Louisiana shelf which provided the data analyzed here. Data analyzed includes profiles of velocity, temperature and salinity taken around the Bank in Oct., 1980 and March, 1981. Fixed current meter moorings and a dye experiment conducted in the bottom boundary layer provided additional input. The data reveals a very complicated flow regime around the bank, with some intensification of flow around and over the bank but no movement of water from the bottom of the surrounding shelf up onto the bank.

  4. Assessment of remaining recoverable oil in selected major oil fields of the Permian Basin, Texas and New Mexico

    USGS Publications Warehouse

    Tennyson, Marilyn E.; Cook, Troy A.; Charpentier, Ronald R.; Gautier, Donald L.; Klett, Timothy R.; Verma, Mahendra K.; Ryder, Robert T.; Attanasi, E.D.; Freeman, P.A.; Le, Phoung A.

    2012-01-01

    The U.S. Geological Survey (USGS) recently completed an estimate of technically recoverable, conventional oil in selected oil fields in the Permian Basin in west Texas and southeastern New Mexico. The mean total volume of potential additional oil resources that might be added using improved oil-recovery technologies was estimated to be about 2.7 billion barrels of oil.

  5. Geochemical constraints on magma processes in a peralkaline system - The Paisano volcano, west Texas

    NASA Technical Reports Server (NTRS)

    Mcdonough, W. F.; Nelson, D. O.

    1984-01-01

    Petrographic and trace element data from a continuous stratigraphic sequence of flows from the peralkaline Paisano Volcano in west Texas are used to delineate magnetic processes responsible for the chemical evolution of this volcano. It is shown that crystal fractionation of the phenocrystic assemblage explains the main compositional variation, but magma mixing of a less evolved melt composition also affected the chemical evolution of the volcano.

  6. West Texas nursing education portal project: developing a regional centralized application system.

    PubMed

    Allen, Patricia; Billings, Lynda; Cannon, Sharon; Majors, Jennifer; Sportsman, Susan; Ballesteros, Pauline A; Bezinque, Kim; Bolton, Cathy; Cottenoir, Marla; Edwards, Carmen; Louder, Justin; O'Neal, Cynthia; Morgan, Jackolyn; Reyes, Helen; Ross, Linda

    2011-01-01

    Because of the nursing shortage and a demand for maximum enrollment, a group of five baccalaureate and seven associate degree nursing programs in West Texas first met in 2007 to form the West Texas Nursing Education Consortium (WTNEC). To emphasize the importance of scale and distance, the West Texas region is larger than all of the northeastern states combined. The founding group agreed that the first mission of WTNEC should be to pool resources in order to increase admission and graduation rates for WTNEC schools. Two years later, this mission is being accomplished by the implementation of a plan designed to increase participating schools' admissions, retention, and graduation rates. A grant proposal was written and funded to develop a central regionalization of the application process for entry into WTNEC generic programs (associates degree in nursing and bachelor of science in nursing), with the goal of decreasing and possibly eliminating student vacancy rates in member schools and perhaps reducing the resources needed by each school for the admission process. The implemented centralized application system allowed prospective students to apply online to the centralized admission portal. Students maintained the freedom to choose the nursing program(s) they wanted to attend, but they were also made aware of possible openings in other participating schools. The admission portal also saved potential students time and money by submitting one centralized application, resulting in consolidation of the nursing school application process. Eleven of the 12 consortium schools participated in the centralized application system. PMID:21596353

  7. Optical properties of Aeolian dusts common to West Texas

    NASA Astrophysics Data System (ADS)

    Ma, Lulu; Zobeck, Ted M.; Hsieh, Daniel H.; Holder, Dean; Morgan, Cristine L. S.; Thompson, Jonathan E.

    2011-11-01

    Both recent models and historical events such as the Dust Bowl and volcanic eruptions have illustrated aerosols can play a significant role in climate change through direct and indirect optical effects. Soil dust aerosols generated by Aeolian processes represent a significant fraction of the total mass burden of atmospheric particles. Central to a better understanding of the climate effects of dust aerosols is knowledge of their optical properties. This research study utilized a dust generator and several instruments to determine certain optical properties of Aeolian dust mimics created by the Amarillo and Pullman soil types native to the panhandle of Texas, USA. Values for the mass-extinction coefficient ranged between 1.74 and 2.97 m 2 g -1 at 522 nm depending on how mass concentration was determined. Single-scatter albedo (SSA) for both soil types ranged from 0.947 to 0.980 at visible wavelengths with SSA increasing at longer wavelengths. Angstrom absorption exponents were measured as 1.73 for Pullman and 2.17 for Amarillo soil. Observed Angstrom extinction exponents were 0.110 and 0.168 for the Pullman and Amarillo soil types. The optical properties reported may be of use for optical based estimates of soil erosion and aid in understanding how regional soil dusts may alter radiative transport presently and during historical events such as the Dust Bowl era.

  8. Assessment of Undiscovered Oil and Gas Resources of the Permian Basin Province of West Texas and Southeast New Mexico, 2007

    USGS Publications Warehouse

    Schenk, Christopher J.; Pollastro, Richard M.; Cook, Troy A.; Pawlewicz, Mark J.; Klett, Timothy R.; Charpentier, Ronald R.; Cook, Harry E.

    2008-01-01

    The U.S. Geological Survey (USGS) recently assessed the undiscovered oil and gas potential of the Permian Basin Province of west Texas and southeast New Mexico. The assessment was geology based and used the total petroleum system concept. The geologic elements of a total petroleum system are petroleum source rocks (quality, source rock maturation, generation, and migration), reservoir rocks (sequence stratigraphy, petrophysical properties), and traps (trap formation and timing). This study assessed potential for technically recoverable resources in new field discoveries only; field growth (or reserve growth) of conventional oil and gas fields was not included. Using this methodology, the U.S. Geological Survey estimated a mean of 41 trillion cubic feet of undiscovered natural gas and a mean of 1.3 billion barrels of undiscovered oil in the Permian Basin Province.

  9. Karst-controlled reservoir heterogeneity in Ellenburger group carbonates of west Texas: Discussion

    SciTech Connect

    Mazzullo, S.J. )

    1990-07-01

    A discussion is presented on a paper by Charles Kerans (AAPG Bull. 1988). The paper dealt with karst-associated porosity and hydrocarbon reservoir heterogenity in Ellengurger (Lower Ordovician) carbonates in the Permian basin of west Texas. The purpose of this paper is not to dispute the model presented by Kerans, but instead to present some alternative models of reservoir occurrence that are not considered in his paper and that are also widely applicable to the Ellenburger and correlative strata in the Mid-Continent. The discussion is based on regional lithostratigraphy and subsurface mapping studies of the Ellenburger in the southern Midland basin, specifically in Irion, Reagan, Crockett, Schleicher, and Sterling counties (Texas).

  10. Application of Advanced Reservoir Characterization, Simulation, and Production Optimization Strategies to Maximize Recovery in Slope and Basin Clastic Reservoirs, West Texas (Delaware Basin), Class III

    SciTech Connect

    Dutton, Shirley P.; Flanders, William A.; Mendez, Daniel L.

    2001-05-08

    The objective of this Class 3 project was demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstone's of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost effective way to recover oil more economically through geologically based field development. This project was focused on East Ford field, a Delaware Mountain Group field that produced from the upper Bell Canyon Formation (Ramsey sandstone). The field, discovered in 9160, is operated by Oral Petco, Inc., as the East Ford unit. A CO2 flood was being conducted in the unit, and this flood is the Phase 2 demonstration for the project.

  11. Yard flooding by irrigation canals increased the risk of West Nile disease in El Paso, Texas

    PubMed Central

    Cardenas, Victor M.; Jaime, Javier; Ford, Paula B.; Gonzalez, Fernando J.; Carrillo, Irma; Gallegos, Jorge E.; Watts, Douglas M.

    2011-01-01

    Purpose To investigate the effects of use of water from irrigation canals to flood residential yards on the risk of West Nile disease in El Paso, Texas. Methods West Nile disease confirmed cases in 2009–2010 were compared with a random sample of 50 residents of the county according to access to and use of water from irrigation canals by subjects or their neighbors, as well as geo-referenced closest distance between their home address and the nearest irrigation canal. A windshield survey of 600 meters around the study subjects’ home address recorded the presence of irrigation canals. The distance from the residence of 182 confirmed cases of West Nile disease reported in 2003–2010 to canals was compared to that of the centroids of 182 blocks selected at random. Results Cases were more likely than controls to report their neighbors flooded their yards with water from canals. Irrigation canals were more often observed in neighborhoods of cases than of controls. Using the set of addresses of 182 confirmed cases and 182 hypothetic controls the authors found a statistically significant inverse relation with risk of West Nile disease. Conclusions Flooding of yards with water from canals increased the risk of West Nile disease. PMID:21943648

  12. Confirmation of Bacillus anthracis from flesh-eating flies collected during a West Texas anthrax season.

    PubMed

    Blackburn, Jason K; Curtis, Andrew; Hadfield, Ted L; O'Shea, Bob; Mitchell, Mark A; Hugh-Jones, Martin E

    2010-07-01

    This case study confirms the interaction between necrophilic flies and white-tailed deer, Odocoileus virginianus, during an anthrax outbreak in West Texas (summer 2005). Bacillus anthracis was identified by culture and PCR from one of eight pooled fly collections from deer carcasses on a deer ranch with a well-documented history of anthrax. These results provide the first known isolation of B. anthracis from flesh-eating flies associated with a wildlife anthrax outbreak in North America and are discussed in the context of wildlife ecology and anthrax epizootics. PMID:20688697

  13. Fracture characterization and discrimination criteria for karst and tectonic fractures in the Ellenburger Group, West Texas: Implications for reservoir and exploration models

    SciTech Connect

    Hoak, T.E. |; Sundberg, K.R.; Deyhim, P.; Ortoleva, P.

    1998-12-31

    In the Ellenburger Group fractured dolomite reservoirs of West Texas, it is extremely difficult to distinguish between multiple phases of karst-related fracturing, modifications to the karst system during burial, and overprinting tectonic fractures. From the analyses of drill core, the authors developed criteria to distinguish between karst and tectonic fractures. In addition, they have applied these criteria within the context of a detailed diagenetic cement history that allows them to further refine the fracture genesis and chronology. In these analyses, the authors evaluated the relationships between fracture intensity, morphologic attributes, host lithology, fracture cement, and oil-staining. From this analysis, they have been able to characterize variations in Ellenburger tectonic fracture intensity by separating these fractures from karst-related features. In general, the majority of fracturing in the Ellenburger is caused by karst-related fracturing although a considerable percentage is caused by tectonism. These findings underscore the importance of considering the complete geologic evolution of a karst reservoir during exploration and field development programs. The authors have been able to more precisely define the spatial significance of the fracture data sets by use of oriented core from Andector Field. They have also demonstrated the importance of these results for exploration and reservoir development programs in West Texas, and the potential to extrapolate these results around the globe. Given the historic interest in the large hydrocarbon reserves in West Texas carbonate reservoirs, results of this study will have tremendous implications for exploration and production strategies targeting vuggy, fractured carbonate systems not only in West Texas, but throughout the globe.

  14. Application of Advanced Reservoir Characterization, Simulation, and Production Optimization Strategies to Maximize Recovery in Slope and Basin Clastic Reservoirs, West Texas (Delaware Basin), Class III

    SciTech Connect

    Dutton, Shirley P.; Flanders, William A.

    2001-11-04

    The objective of this Class III project was demonstrate that reservoir characterization and enhanced oil recovery (EOR) by CO2 flood can increase production from slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico. Phase 1 of the project, reservoir characterization, focused on Geraldine Ford and East Ford fields, which are Delaware Mountain Group fields that produce from the upper Bell Canyon Formation (Ramsey sandstone). The demonstration phase of the project was a CO2 flood conducted in East Ford field, which is operated by Orla Petco, Inc., as the East Ford unit.

  15. Aerial radiometric and magnetic survey, San Angelo National Topographic Map: Texas, West Texas Project. Final report

    SciTech Connect

    Not Available

    1980-05-01

    The results of analyses of the airborne gamma radiation and total magnetic field survey flown for the region identified as the San Angelo National Topographic Map NH14-1 are presented. The airborne data gathered are reduced by ground computer facilities to yield profile plots of the basic uranium, thorium, and potassium equivalent gamma radiation intensities, ratios of these intensities, aircraft altitude above the earth's surface, total gamma ray and earth's magnetic field intensity, correlated as a function of geologic units. The distribution of data within each geologic unit, for all surveyed map lines and tie lines, has been calculated and is included. Two sets of profiled data for each line are included, with one set displaying the above-cited data. The second set includes only flight line magnetic field, temperature, pressure, altitude data plus magnetic field data as measured at a base station. A general description of the area, including descriptions of the various geologic units and the corresponding airborne data, is included.

  16. Cross-correlations between West Texas Intermediate crude oil and the stock markets of the BRIC

    NASA Astrophysics Data System (ADS)

    Ma, Feng; Wei, Yu; Huang, Dengshi; Zhao, Lin

    2013-11-01

    In this paper, we investigate the cross-correlation properties between West Texas Intermediate crude oil and the stock markets of the BRIC. We use not only the qualitative analysis of the cross-correlation test, but also take the quantitative analysis of the MF-DXA, confirming the cross-correlation relationship between West Texas Intermediate crude oil and the stock markets of the BRIC (Brazil, Russia, India and China) respectively, which have strongly multifractal features, and the cross-correlations are more strongly multifractal in the short term than in the long term. Furthermore, based on the multifractal spectrum, we also find the multifractality strength between the crude oil WTI and Chinese stock market is stronger than the multifractality strength of other pairs. Based on the Iraq war (Mar 20, 2003) and the Financial crisis in 2008, we divide sample period into four segments to research the degree of the multifractal (ΔH) and the market efficiency (and the risk). Finally, we employ the technique of the rolling window to calculate the time-varying EI (efficiency index) and dependent on the EI, we can easily observe the change of stock markets. Furthermore, we explore the relationship between bivariate cross-correlation exponents (Hxy(q)) and the generalized Hurst exponents.

  17. Geologic and Engineering Characterization of East Ford Field, Reeves County, Texas

    SciTech Connect

    Dutton, Shirley P.; Flanders, William A.; Guzman, Jose I.; Zirczy, Helena

    1999-08-16

    The objective of this Class III project is to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost-effective way to recover a higher percentage of the original oil in place through geologically based field development. The project focused on reservoir characterization of the East Ford unit, a representative Delaware Mountain Group field that produces from the upper Bell Canyon Formation (Ramsey Sandstone). The field, discovered in 1960, is operated by Oral Petco, Inc., as the East Ford unit: it contained an estimated 18.4 million barrels (MMbbl) of original oil in place.

  18. Association of hypothyroidism with low-level arsenic exposure in rural West Texas

    SciTech Connect

    Gong, Gordon; Basom, Janet; Mattevada, Sravan; Onger, Frederick

    2015-04-15

    It has been reported recently that a higher airborne arsenic level was correlated with higher urinary arsenic concentration and lower serum thyroxin level among urban policemen and rural highway workmen in Italy. The current study was to determine whether exposure to low-level arsenic groundwater (2–22 µg/L) is associated with hypothyroidism among 723 participants (118 male and 267 female Hispanics; 108 male and 230 female non-Hispanic whites, NHW) living in rural West Texas counties. Arsenic and iodine levels in their groundwater used for drinking and or cooking were estimated by the inverse distance weighted (IDW) interpolation technique. Groundwater arsenic was ≥8 µg/L in 36% of the subjects' wells while iodine concentration was <1 µg/L in 91% of their wells. Logistic regression analysis showed that arsenic in groundwater ≥8 µg/L and cumulative arsenic exposure (groundwater arsenic concentration multiplied by the number of years living in the current address) but not groundwater iodine concentration were significant predictors for hypothyroidism among Hispanics (p<0.05) but not NHW after adjusting for covariates such as age, gender, annual household income and health insurance coverage. The ethnic difference may be due to a marginally higher percentage of Hispanics (p=0.0622) who lived in areas with groundwater arsenic ≥8 µg/L compared with NHW. The prevalence of hypothyroidism was significantly higher in Hispanics or NHW of this rural cohort than the national prevalence. Measures should be taken to reduce arsenic in drinking water in order to prevent hypothyroidism in rural areas. - Highlights: • We determined if arsenic exposure is associated with hypothyroidism in rural Texas. • Groundwater arsenic level is associated with hypothyroidism among Hispanics only. • The rate of hypothyroidism in rural Texas was higher than the US general population.

  19. Depositional systems and Karst geology of the Ellenburger group (lower ordovician), subsurface West Texas

    SciTech Connect

    Kerans, C.

    1990-01-01

    The Ellenburger Group of Texas contains estimated reserves of 1.15 billion barrels of oil and 2.2 billion barrels of oil equivalent. Despite its economic significance, comparatively little is known about the subsurface Ellenburger in West Texas; thus, this book presents a regional model of Ellenburger deposition and diagenesis. Using associations of lithologies and sedimentary structures observed in core, the author identified six depositional systems in the Ellenburger: fan delta-marginal marine, lower tidal flat, high-energy restricted shelf, low-energy restricted shelf, upper tidal flat, and open shallow water shelf. Diagenesis was dominated by three major styles of dolomitization: very fine crystalline dolomite (5-20 {mu}m), in tidal-flat facies; fine to medium crystalline dolomite (20-100 {mu}m), widespread in all facies; and coarse crystalline replacement mosaic dolomite and saddle dolomite cement, which formed in a burial setting after pre-Simpson karst formation and before Pennsylvanian faulting, uplift, and erosion. Other diagenetic events were karst-related dissolution episodes associated with repeated uplift and exposure and subsequent dedolomitization of the Ellenburger platform.

  20. Spatiotemporal associations of reservoir nutrient characteristics and the invasive, harmful alga Prymnesium parvum in West Texas

    USGS Publications Warehouse

    VanLandeghem, Matthew M.; Farooqi, Mukhtar; Southard, Greg M.; Patino, Reynaldo

    2015-01-01

    Golden alga (Prymnesium parvum) is a harmful alga that has caused ecological and economic harm in freshwater and marine systems worldwide. In inland systems of North America, toxic blooms have nearly eliminated fish populations in some systems. Modifying nutrient profiles through alterations to land or water use may be a viable alternative for golden alga control in reservoirs. The main objective of this study was to improve our understanding of the nutrient dynamics that influence golden alga bloom formation and toxicity in west Texas reservoirs. We examined eight sites in the Upper Colorado River basin, Texas: three impacted reservoirs that have experienced repeated golden alga blooms; two reference reservoirs where golden alga is present but nontoxic; and three confluence sites downstream of the impacted and reference sites. Total, inorganic, and organic nitrogen and phosphorus and their ratios were quantified monthly along with golden alga abundance and ichthyotoxicity between December 2010 and July 2011. Blooms persisted for several months at the impacted sites, which were characterized by high organic nitrogen and low inorganic nitrogen. At impacted sites, abundance was positively associated with inorganic phosphorus and bloom termination coincided with increases in inorganic nitrogen and decreases in inorganic phosphorus in late spring. Management of both inorganic and organic forms of nutrients may create conditions in reservoirs unfavorable to golden alga.

  1. Structural subprovinces of the Central Basin Platform, west Texas: Strike-slip bounded crustal blocks

    SciTech Connect

    Gardiner, W.B. )

    1990-05-01

    The Central Basin platform (CBP) of west Texas is composed of six structural blocks, which moved independently during the Ouachita orogeny. As the South American plate collided with North America the Wasson uplift on the northwestern shelf of the Permian basin acted as a buttress against which the CBP was compressed. Shear forces transmitted through the crust resulted in buckling, uplifting, and faulting of the greater CBP. Although the platform is dominated by vertical movement, it did not however, uplift as a single tectonic unit. Rather, it splintered into six megablocks, which moved simultaneously along oblique-slip fault systems. A tectonic model for formation of the CBP is useful for predicting the orientation and spacing of fault systems. The three structurally highest blocks on the CBP, the Eunice high, the Sand Hills high, and the Fort Stockton uplift, show three distinct positive gravity and magnetic anomalies. These county-sized blocks (35 x 80 km) share similar characteristics: (1) they are bounded by strike-slip faults that involve basement uplift; (2) they have maximum structural deformation along their margins where bends in the strike-slip fault system enhance compressions; and (3) their oil is trapped in high-angle fault structures (R-shears ) along the clock boundaries, but toward the center of the blocks, oil tends to accumulate at unconformity and fold traps. Strike-slip fault systems in west Texas are subtle, with only about 3-7 km of offset and commonly may be overlooked. However, detailed regional mapping indicates that these individual fault segments are parts of through-going systems, which are distributed in logical patterns based upon models for strike-slip tectonics.

  2. Giant gas field of northern West Siberia

    SciTech Connect

    Grace, J.D.; Hart, G.F.

    1986-06-01

    The 66 fields discovered since the 1960s in the northern West Siberian basin contain at least 22 trillion m/sup 3/ (777 tcf) of proved gas, almost one-third of the world's reserves. Half of these fields are giants (> 85 billion m/sup 3/ or 3000 bcf of reserves). These include the largest and second-largest gas fields in the world-Urengoy (8.099 trillion m/sup 3/ or 286 tcf of gas) and Yamburg (4.81 trillion m/sup 3/ or 170 tcf of gas)-as well as most of the other ten largest gas fields in the world. The West Siberian basin occupies a 3.4-million km/sup 2/ (1.31-million mi/sup 2/) arctic lowland immediately east of the Ural Mountains, extending north under the Kara Sea. It is a composite basin, with Mesozoic-Cenozoic basin fill on top of a Paleozoic basin that overlies a crystalline Archean-Proterozoic framework. The productive zones in the northern basin are principally in the Neocomian section (at an average depth of 2800m or 9200 ft) and the Cenomanian section (at an average depth of 2800 m or 9200 ft) and the Cenomanian section (at an average depth of 1100 m or 3600 ft). The former contains reservoirs with gas, condensate, and oil; the latter contains two-thirds of the region's gas. Gas in Cenomanian reservoirs is almost pure methane. Hydrocarbons in Neocomian reservoirs were generated by thermal maturation of sapropelic organic matter contained principally in the Tithonian Bazhenov shale. Methane in the Cenomanian section appears to be a combination of thermogenic gas from the Bazhenov Suite (or deeper) and biogenic gas generated in the Cenomanian section itself, although workers disagree over how much gas came from each source. Continental glaciation during the Pleistocene may have been important in concentrating the methane in Cenomanian reservoirs.

  3. APPLICATION OF AN AREA-OF-REVIEW (AOR) CONCEPT TO THE EAST TEXAS FIELD AND OTHER SELECTED TEXAS OILFIELDS

    SciTech Connect

    Don L. Warner; Leonard F. Koederitz; Robert C. Laudon

    1997-07-01

    The Underground Injection Control (UIC) regulations of the US Environmental Protection Agency (EPA) require an Area-of-Review (AOR) study for newly drilled or converted Class II injection wells. In Texas, the UIC program is administered by the Texas Railroad Commission. A Federal Advisory Committee (FAC) formed by the EPA recommended, in 1992, that exceptions to the AOR requirement should be allowed for wells in those areas where a variance has been granted because there is sufficiently low risk of upward fluid migration from the injection zone into an underground source of drinking water. The FAC listed conditions that could be considered in determining whether to grant a variance. The University of Missouri-Rolla (UMR), under contract with the American Petroleum Institute, then expanded the FAC AOR variance conditions into an AOR variance methodology. A Department of Energy (DOE) grant to UMR, for which this is the final report, provided for study of the application of the AOR variance methodology to the East Texas field and to other selected Texas oilfields. A final report on the East Texas field portion of the DOE project was submitted by UMR to DOE in 1995. This current final report describes the results of UMR's study of AOR variance opportunities in the Texas Gulf Coast Frio Formation oil producing trend. In the course of this study, AOR variance opportunities were examined for 73 oilfields in nine Texas Gulf Coast counties. It is believed that the combination of well construction and abandonment characteristics plus the presence of sloughing and squeezing shales and porous and permeable sand sink zones provide for the possibility of AOR variances in 57 of the 73 study fields. The remaining 16 fields are ones where the oil accumulations occur in conjunction with shallow salt domes and where geologic conditions are probably too complex to allow field-wide AOR variances. The successful study results can probably be extended to at least 78 additional oilfields

  4. Winter habitat use and survival of lesser prairie-chickens in West Texas

    USGS Publications Warehouse

    Pirius, Nicholas E.; Boal, Clint W.; Haukos, David A.; Wallace, M.C.

    2013-01-01

    The lesser prairie-chicken (Tympanuchus pallidicinctus) has experienced declines in population and occupied range since the late 1800s and is currently proposed for Federal protection under the Endangered Species Act. Populations and the distribution of lesser prairie-chickens in Texas, USA, are thought to be at or near all-time lows. Currently, there is a paucity of data on the wintering ecology of the species. We measured home range, habitat use, and survival of lesser prairie-chickens during the non-breeding seasons (1 Sep-28 Feb) of 2008-2009, 2009-2010, and 2010-2011 in sand shinnery oak (Quercus havardii) landscapes in the West Texas panhandle region. Home range size did not differ among years or between females (503 ha) andmales (489 ha). Over 97% of locations of both male and female prairie-chickens were within 3.2 km of the lek of capture, and 99.9% were within 3.2 km of an available water source (i.e., livestock water tank). Habitat cover types were not used proportional to occurrence within the home ranges; grassland-dominated areas with co-occurring sand shinnery oak were used more than available, but sand sagebrush (Artemisia filifolia)-dominated areas with grassland and sand sagebrush-dominated areas with bare ground were both used less than available. Survival rates during the first 2 non-breeding seasons (>80%) were among the highest reported for the species. However, survival during the third non-breeding season was only 57%, resulting in a 3-year average of 72%. It does not appear that non-breeding season mortality is a strong limiting factor in lesser prairie-chicken persistence in the study area.

  5. Hylton northwest field's tectonic effect on Suggs Ellenburger producing area, Nolan County, Texas

    SciTech Connect

    Hoffacker, B.F. Jr.

    1987-02-01

    An evaluation of the geology of Hylton Northwest field in southeastern Nolan County, Texas, indicates that the pre-Pennsylvanian tectonics associated with this field may have affected the producing zone of Suggs Ellenburger field 6 mi (9 km) west. Both fields are located along the Fort Chadbourne fault system of the Eastern shelf of the Midland basin. The study of the depositional environment of the Suggs Ellenburger field reveals some interesting aspects of the tectonostratigraphic terrane that appears to have in part influenced the development of the reservoir rock. The tectonics of the Cambrian-Ordovician (Ellenburger) period in Hylton Northwest field created a southwest-trending fault system with associated fractures. The fractures allowed percolating surface waters to leach carbonate rocks in the area, creating vuggy secondary porosity in the intercrystalline rock fabric. The faults were modified to a karst topography by periods of subaerial erosion of the Cambrian-Ordovician depositional plain. Sea level fluctuations that occurred in the area were associated with the alternating uplift and subsidence of the Hylton Northwest field's tectonic feature. As a result, environmental zones of porosity with varying vertical subaerial erosion formed within the overall Cambrian-Ordovician (Ellenburger) interval. The producing zone of the Suggs Ellenburger field occurs at approximately 6,400 ft (1,951 m).

  6. Application of advanced reservoir characterization, simulation, and production optimization strategies to maximize recovery in slope and basin clastic reservoirs, West Texas (Delaware Basin), Class III

    SciTech Connect

    Dutton, Shirley P.; Flanders, William A.; Zirczy, Helena H.

    2000-05-24

    The objective of this Class 3 project was to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost effective way to recover a higher percentage of the original oil in place through strategic placement of infill wells and geologically based field development. Phase 1 of the project, reservoir characterization, was completed this year, and Phase 2 began. The project is focused on East Ford field, a representative Delaware Mountain Group field that produces from the upper Bell Canyon Formation (Ramsey sandstone). The field, discovered in 1960, is operated by Oral Petco, Inc., as the East Ford unit. A CO{sub 2} flood is being conducted in the unit, and this flood is the Phase 2 demonstration for the project.

  7. Shelf margin bioherms and associated facies in the Lower Permian Hueco Group (Late Wolfcampian), Hueco Mountains, West Texas

    SciTech Connect

    Wahlman, G.P.; Tasker, D.R.; St. John, J.W.; Werle, K.J. )

    1992-01-01

    Late Wolfcampian phylloid algal/Tubiphytes biohermal complexes are exposed in three erosional oilers lying about 3 miles west of and parallel to the main Hueco Mountains in far West Texas. The biohermal complexes are located paleogeographically along the shelf margin between the Diablo Platform and Orogrande Basin. Based on fusulinids the shelf margin buildups correlate with well-bedded shelf carbonates of the type Hueco Group in the main Hueco Mountains. The phylloid algal/Tubiphytes shelf margin bioherms contain an upward shallowing facies succession, which, in ascending order, consists of: (1) phylloid algal wackestone-bafflestone, (2) phylloid algal-fusulinid bafflestone-packstone, and (3) Tubiphytes boundstone and Tubiphytes-fusulinid-phylloid algal packstone-grainstone. The crest of the southernmost outlier has a different type of bioherm that consists of nodular boundstones composed of calcisponges, encrusting bryozoans and laminar red algae. The shelf margin complexes prograded over slope facies of dark-gray cherty limestones, which generally lack skeletal fossils, but contain common ichnofossils in upper slope beds. Overlapping tongues and channels of lithoclastic-skeletal packstones and grainstones extend seaward from the phylloid algal/Tubiphytes bioherms into the dark-gray slope facies. Proximal backreef facies consist of mainly skeletal-peloidal packstones and wackestones. The Hueco Mountains outlier exposures are important because: (1) they confirm a Late Wolfcampian shelf margin with distinct topographic relief in the southern Orogrande Basin, and (2) they provide an easily accessible field laboratory where Wolfcampian shelf-to-basin facies relationships and shelf margin bioherms can be studied. Wolfcampian bioherms represent a significant stage in the evolutionary history of Late Paleozoic reef communities and form important petroleum reservoirs in the adjacent Permian Basin.

  8. Magnetostratigraphy susceptibility for the Guadalupian Series GSSPs (Middle Permian) in Guadalupe Mountains National Park and adjacent areas in West Texas

    USGS Publications Warehouse

    Wardlaw, Bruce R.; Ellwood, Brooks B.; Lambert, Lance L.; Tomkin, Jonathan H.; Bell, Gordon L.; Nestell, Galina P.

    2012-01-01

    Here we establish a magnetostratigraphy susceptibility zonation for the three Middle Permian Global boundary Stratotype Sections and Points (GSSPs) that have recently been defined, located in Guadalupe Mountains National Park, West Texas, USA. These GSSPs, all within the Middle Permian Guadalupian Series, define (1) the base of the Roadian Stage (base of the Guadalupian Series), (2) the base of the Wordian Stage and (3) the base of the Capitanian Stage. Data from two additional stratigraphic successions in the region, equivalent in age to the Kungurian–Roadian and Wordian–Capitanian boundary intervals, are also reported. Based on low-field, mass specific magnetic susceptibility (χ) measurements of 706 closely spaced samples from these stratigraphic sections and time-series analysis of one of these sections, we (1) define the magnetostratigraphy susceptibility zonation for the three Guadalupian Series Global boundary Stratotype Sections and Points; (2) demonstrate that χ datasets provide a proxy for climate cyclicity; (3) give quantitative estimates of the time it took for some of these sediments to accumulate; (4) give the rates at which sediments were accumulated; (5) allow more precise correlation to equivalent sections in the region; (6) identify anomalous stratigraphic horizons; and (7) give estimates for timing and duration of geological events within sections.

  9. Subsurface Glen Rose reef trend in east Texas and west-central Louisiana

    SciTech Connect

    Adams, G.S.

    1983-03-01

    The subsurface Glen Rose reef trend in east Texas and west-central Louisiana (Lower Cretaceous Comanchean) is a regressive carbonate complex deposited on a broad shallow water shelf. The Glen Rose reef trend can be differentiated into two separate reef tracts that prograded seaward over a slowly subsiding shelf. It remains to be seen whether the Glen Rose reefs are actual framework reefs or mounds of transported material. Reef facies include poorly sorted caprinidcoral grainstones, moderately sorted peloid and oncolite packstones and grainstones, and well-sorted, very fine grained skeletal grainstones. Coated grains, abraded skeletal fragments, scoured bedding surfaces, and minor cross-beds are evidence for deposition of the reef facies in a high-energy shoal setting. The reefal buildups grade laterally into low-energy shallow water wackestones and mudstones containing toucasids, orbitolinids, and serpulid burrows. Porosities associated with the reefal buildups appear facies controlled. Caprinid-coral packstones and grainstones exhibit intraparticle, moldic, and vuggy porosities of 10 to 15%. Pinpoint microporosity of 5 to 10% are found within the finegrained skeletal grainstones. Fracture porosity enhances permeability in several facies. Moldic and vuggy porosity types are generally secondary whereas intraparticle porosity may be preserved primary. Coarse equant calcite commonly occludes intraparticle, moldic, vuggy, and fracture porosities. Dolomitization within the reef limestones may have acted to create or preserve porosities. Poor production from the Glen Rose reef trend has been attributed to the lack of structural closure.

  10. Carbonate facies and stratigraphic framework of middle Magdalena (middle Pennsylvanian), Hueco Mountains, west Texas

    SciTech Connect

    Lambert, L.L.; Stanton, R.J. Jr.

    1988-01-01

    The middle Magdalena of the Hueco Mountains, west Texas, is best exposed in the vicinity of Pow Wow Canyon, particularly along the western scarp of the range. It can be divided into two major depositional sequences, the lowermost of which consists predominantly of alternating bank, interbank, and shoal deposits of Atokan age. These banks are low-relief accumulations of Donezella, with coeval slackwater skeletal wackestones and interbedded deposits of foraminiferal sands. A prominent zone of intertonguing Chaetetes biostromes punctuates the middle part of this sequence. The Desmoinesian sequence begins as a series of rubbly limestones in association with abundant silicified plant remains and is interpreted as a set of paleosols. These are overlain by argillaceous, low-diversity wackestones and packstones of lagoonal origin, followed by carbonates of more open-marine circulation with abundant corals and other stenotypic fossils. In turn, these deposits are succeeded by a sequence of phylloid algal banks that increase in resistance upward to where they represent strata of the upper Magdalena. At this locality, however, the upper Magdalena is very thin because it is truncated by the pre-Hueco unconformity which, so prominent at the head of the canyon, can now be traced to the western scarp. These deposits are directly analogous to subsurface reservoir facies of the same age on the opposite side of the Diablo uplift in the Permian basin and thus provide an opportunity to generate reservoir models based on extensive outcrop exposure.

  11. Origin of micro-rhombic calcite matrix within Cretaceous reservoir rock, West Stuart City Trend, Texas

    NASA Astrophysics Data System (ADS)

    Perkins, Ronald D.

    1989-07-01

    Cores from four wells from the West Stuart City Trend in La Salle and Webb Counties, Texas, were analyzed to define depositional and diagenetic facies and to determine factors controlling porosity distribution. In all, 1187 ft (362 m) of core and 220 thin sections were examined in detail and supplemented by SEM analyses of fractured surfaces and plastic casts of pore systems. A comparison of lithofacies and ecologic facies to permeability and porosity values compiled from core data revealed that zones with permeabilities greater than 0.1 md and porosities of at least 6% were associated with rudistid grainstones cemented by isopachous, submarine cement and packstones with a finely crystalline rhombic calcite matrix. Isotopic and trace element analyses of both isopachous submarine cements and micro-rhombic matrix suggest a common origin. The precursor to the micro-rhombic calcite is believed to have been peloidal, high-magnesian calcite. This internal marine sediment may be analogous to the peloidal fabrics that have been reported from Holocene and Pleistocene carbonates. Diagenetic equilibration of both submarine cements and peloidal infill is believed to have occurred during burial either in marine pore waters at elevated temperatures or in restricted flow, phreatic freshwaters.

  12. Helminths of sympatric striped, hog-nosed, and spotted skunks in west-central Texas.

    PubMed

    Neiswenter, Sean A; Pence, Danny B; Dowler, Robert C

    2006-07-01

    Twenty-eight hog-nosed skunks (Conepatus leuconotus), 23 striped skunks (Mephitis mephitis), and nine spotted skunks (Spilogale gracilis) from an area of sympatry in west-central Texas were examined for helminth parasites. Shared helminth species among all three host species were one nematode (Physaloptera maxillaris), two acanthocephalans (Pachysentis canicola, Macracanthorhynchus ingens), and one cestode (Mathevotaenia mephitis). Two nematodes (Gongylonema sp. and Filaria taxidaea) occurred in both the striped and hog-nosed skunks. One nematode (Filaroides milksi) and one acanthocephalan (Oncicola canis) were collected only from C. leuconotus. The most common helminth infections for striped and hog-nosed skunks were P. maxillaris and P. canicola. Helminth species richness was highest in hog-nosed skunks, but striped skunks had the highest prevalences and intensities of all the common helminth species. The helminth fauna of spotted skunks was markedly depauperate in terms of species richness and helminth abundance compared to the other two host species. Differences in helminth communities across these three sympatric skunks may be related to differences in their relative abundance, behavior, food habits, and geographic range. PMID:17092881

  13. Detachment levels in the Marathon fold and thrust belt, west Texas

    NASA Astrophysics Data System (ADS)

    Chapman, James B.; McCarty, Reid S.

    2013-04-01

    Surface and subsurface data are integrated to characterize the structural architecture of the Marathon fold and thrust belt in west Texas. Multiple detachment levels are present within the thrust belt and result in distinct structural domains. In addition to the basal décollement, whose stratigraphic position varies along strike, we recognize a regionally extensive detachment zone in the late Mississippian to early Pennsylvanian lower Tesnus Formation. The Lower Tesnus Detachment forms a structural domain boundary that can be observed along strike in the surface data and at depth in the subsurface. The stratigraphic intervals above and below this detachment exhibit characteristic patterns of deformation. The Lower Tesnus Detachment is folded by imbrication and the formation of duplexes in the early Mississippian to Ordovician section, suggesting that the detachment may have initially formed as a perched décollement in the foreland that was subsequently exploited as a roof thrust in a duplex system as deformation progressed in a break-forward sequence and older strata were incorporated into the toe of the allochthonous wedge. The structural model presented here for the Marathon region may be applicable across much of the Ouachita orogenic system.

  14. Upper Permian (Guadalupian) facies and their association with hydrocarbons - Permian basin, west Texas and New Mexico

    SciTech Connect

    Ward, R.F.; Kendall, C.G.S.C.; Harris, P.M.

    1986-03-01

    Outcrops of Guadalupian sedimentary rocks in the Permian basin of west Texas and southeastern New Mexico are a classic example of the facies relationships that span a carbonate shelf. In the subsurface, these rocks form classic hydrocarbon-facies taps. Proceeding from basin to the updip termination of the shelf, the facies are (1) deep-water basin, (2) an apron of allochthonous carbonates, (3) carbonate shelf margin or reef, (4) carbonate sand flats, (5) carbonate barrier islands, (6) lagoon, and (7) coastal playas and supratidal salt flats (sabkhas). Over a half century of exploration drilling has shown that hydrocarbons in the Permian rocks of the Permian basin have accumulated at the updip contact of the lagoonal dolomites and clastics with the coastal evaporites, and in the basinal channel-fill clastics. The shelf marginal (reef) facies contain cavernous porosity, but commonly are water saturated. These facies relationships and hydrocarbon occurrences provide an exploration model with which to explore and rank hydrocarbon potential in other carbonate provinces. 16 figures, 3 tables.

  15. Clarksville field Red River County, Texas: Production and facies interpretation

    SciTech Connect

    Reed, C.H. )

    1991-03-01

    The Clarksville field was discovered in December in 1985 while targeting a deeper paleozoic horizon. Since production went on line in 1986, this field has produced over 1 million barrels of oil (MMBO) with the appearance of a considerably longer and more lucrative life. The producing horizon is a Jurassic-age lithic conglomerate sitting unconformably on the Paleozoic and Triassic structural front of the buried Ouachita range. Facies correlation out of the basin indicate this unit to be Louark age. Mapping and compositional analysis indicate the depositional environmental of this unit to be an arid climate alluvial fan deposited as a 'Bajada' complex. This fan system was laid down at the updip margin of the actively forming Mesozoic embayment where it meets the Ouachita structural front. The significance of this field is demonstrated by the production yield at a relatively shallow depth (5800 ft). At this time, production similar to Clarksville field has yet to be encountered anywhere along the Mesozoic rim of the East Texas basin but does represent a viable exploration trend, in addition to being a gateway for future paleozoic production in the basin.

  16. Application of Advanced Reservoir Characterization, Simulation, and Production Optimization Strategies to Maximize Recovery in Slope and Basin Clastic Reservoirs, West Texas (Delaware Basin)

    SciTech Connect

    Shirley P. Dutton

    1997-07-30

    The objective of this project is to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost effective way to recover a higher percentage of the original oil in place through strategic placement of infill wells and geologically based field development. Project objectives are divided into two major phases. The objectives of the reservoir characterization phase of the project are to provide a detailed understanding of the architecture and heterogeneity of two fields, the Ford Geraldine unit and Ford West field, which produce from the Bell Canyon and Cherry Canyon Formations, respectively, of the Delaware Mountain Group and to compare Bell Canyon and Cherry Canyon reservoirs. Reservoir characterization will utilize 3-D seismic data, high-resolution sequence stratigraphy, subsurface field studies, outcrop characterization, and other techniques. Once the reservoir-characterization study of both fields is completed, a pilot area of approximately 1 mi 2 in one of the fields will be chosen for reservoir simulation.

  17. Association of hypothyroidism with low-level arsenic exposure in rural West Texas.

    PubMed

    Gong, Gordon; Basom, Janet; Mattevada, Sravan; Onger, Frederick

    2015-04-01

    It has been reported recently that a higher airborne arsenic level was correlated with higher urinary arsenic concentration and lower serum thyroxin level among urban policemen and rural highway workmen in Italy. The current study was to determine whether exposure to low-level arsenic groundwater (2-22µg/L) is associated with hypothyroidism among 723 participants (118 male and 267 female Hispanics; 108 male and 230 female non-Hispanic whites, NHW) living in rural West Texas counties. Arsenic and iodine levels in their groundwater used for drinking and or cooking were estimated by the inverse distance weighted (IDW) interpolation technique. Groundwater arsenic was ≥8µg/L in 36% of the subjects' wells while iodine concentration was <1µg/L in 91% of their wells. Logistic regression analysis showed that arsenic in groundwater ≥8µg/L and cumulative arsenic exposure (groundwater arsenic concentration multiplied by the number of years living in the current address) but not groundwater iodine concentration were significant predictors for hypothyroidism among Hispanics (p<0.05) but not NHW after adjusting for covariates such as age, gender, annual household income and health insurance coverage. The ethnic difference may be due to a marginally higher percentage of Hispanics (p=0.0622) who lived in areas with groundwater arsenic ≥8µg/L compared with NHW. The prevalence of hypothyroidism was significantly higher in Hispanics or NHW of this rural cohort than the national prevalence. Measures should be taken to reduce arsenic in drinking water in order to prevent hypothyroidism in rural areas. PMID:25721242

  18. Integrated geological and geophysical studies of the Indio Mountains and Hueco bolson, west Texas

    NASA Astrophysics Data System (ADS)

    Budhathoki, Pawan

    This dissertation consists of two different projects. The first project describes the results of an outcrop based sequence stratigraphic study of the Albian Cox Sandstone in the Indio Mountains of west Texas. The depositional environment of the Cox Sandstone ranges from shallow marine to the coastal plain deposited in four sequences where sequence 1 and sequence 2 consists of transgressive system tracts (TST) followed by highstand system tracts (HST). The highstand system tract (HST) is missing in sequence 3 and the transgressive systems tract is missing in sequence 4. The Cox changes in thickness from 320 m in the northern end of the outcrop belt to 365 m in the southern end. This thickness change is accommodated during transgression where shales drape topography that is actively being shaped by faults and block rotation recorded in exposed growth strata. During Highstand, coarse fluvial-deltaic systems truncate shales on topographic high levelling the topography. Systems tracts and sequences change thickness due to block rotation and erosion as well as deposition from a point source near the center of the outcrop belt. The second project involves the integrated study of gravity and well log data in the northern Hueco bolson. The objective of this study is to demarcate subsurface faults that appear to control the locations of fresh and brackish water. In this study 28 gravity anomalies were identified that correlate with previously mapped (Collins and Raney, 2000) and new faults, and some of them can be extended further south to south east to join with previously mapped faults by Collins and Raney (2000) and Marrufo (2011). Structural cross sections of well logs also suggest that at least some faults are present between them. The four depositional environments inferred from the gamma log responses and their stacking patterns are consistent with the previous interpretation of Doser and Langford (2006) and Marrufo (2011).

  19. Computed and estimated pollutant loads, West Fork Trinity River, Fort Worth, Texas, 1997

    USGS Publications Warehouse

    McKee, Paul W.; McWreath, Harry C.

    2001-01-01

    In 1998 the U.S. Geological Survey, in cooperation with the Trinity River Authority, did a study to estimate storm-runoff pollutant loads using two models?a deterministic model and a statistical model; the estimated loads were compared to loads computed from measured data for a large (118,000 acres) basin in the Dallas-Fort Worth, Texas, metropolitan area. Loads were computed and estimated for 12 properties and constituents in runoff from two 1997 storms at streamflow-gaging station 08048543 West Fork Trinity River at Beach Street in Fort Worth. Each model uses rainfall as a primary variable to estimate pollutant load. In addition to using point rainfall at the Beach Street station to estimate pollutant loads, areal-averaged rainfall for the basin was computed to obtain a more representative estimate of rainfall over the basin. Loads estimated by the models for the two storms, using both point and areal-averaged rainfall, generally did not compare closely to computed loads for the 12 water-quality properties and constituents. Both models overestimated loads more frequently than they underestimated loads. The models tended to yield similar estimates for the same property or constituent. In general, areal-averaged rainfall data yielded better estimates of loads than point rainfall data for both models. Neither the deterministic model nor the statistical model (both using areal-averaged rainfall) was consistently better at estimating loads. Several factors could account for the inability of the models to estimate loads closer to computed loads. Chief among them is the fact that neither model was designed for the specific application of this study.

  20. Ochoan (upper Permian) stratigraphy and age determinations, southeastern New Mexico and west Texas

    SciTech Connect

    Lucas, S.G. ); Anderson, O.R. )

    1994-03-01

    Upper Permian strata, which are the stratotype of the Ochoan State (Series), have an extensive subsurface distribution and limited outcrop area in southeastern New Mexico and west Texas. The oldest strata are alternating laminae of anhydrite and calcite of the Castile Formation and are as much as 700 m thick. The closely related and overlying Salado Formation is a much as 600 m thick and is mostly halite and argillaceous halite with minor anhydrite. The overlying Rustler Formation is as much as 150 m thick and consists of anhydrite, red silty shale and magnesian limestone. Overlying red beds are the Quartermaster Formation (Dewey Lake Formation is a synonym, as is the term Pierce Canyon red beds), which is as much as 106 m thick and consist of fine sandstones, siltstones, and minor gypsum. The Castile rests disconformably on the Capitanian (middle Permian) Lamar Limestone Member of the Bell Canyon Formation and its equivalent, the Tansill Formation of the Artesia Group. Counting of Castile-Salado laminae and their posited relationship to astronomical cycles suggests that Castile-Salado deposition took only 200,000-300,000 yr. Limited assemblages of brachiopods and conodonts from the Rustler Formation indicate a Late Permian age, but are no more precise age indicators. A small assemblage of bivalves, K-Ar ages and magnetostratigraphy indicate a late Permian age for the Quartermaster Formation. There is no evidence to support a Triassic age assignment for the Quarter-master; it is disconformably overlain by the Upper Triassic (Carnian) Chinle group. Most workers us the Ochoan as a Late Permian Stage-Age, although its typical strata generally lack good age indicators and may represent relatively short and sporadic intervals of the Late Permian. We prefer recognition of the Ochoan as a lithostratigraphic unit (group) without regional or global geochronologial significance.

  1. View of sports field and Easter Hill at west side ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of sports field and Easter Hill at west side of project site. Looking west - Easter Hill Village, Bordered by South Twenty-sixth Street, South Twenty-eighth Street, Hinkley Avenue, Foothill Avenue & Corto Square, Richmond, Contra Costa County, CA

  2. Clay mineralogy and its controls on production, Pennsylvanian upper Morrow sandstone, Farnsworth field, Ochiltree County, Texas

    SciTech Connect

    Munson, T.W. )

    1989-12-01

    Farnsworth field in Ochiltree County, Texas, is the most prolific upper Morrow oil field in the Anadarko basin, producing more than 36 million bbl of oil and 27 billion ft{sup 3} of gas since its discovery in 1955. The bulk of the production comes from an upper Morrow-aged sandstone locally referred to as the Buckhaults sandstone. The Buckhaults sandstone is a coarse to very coarse-grained, arkose to arkosic wacke. Grain-size distributions, sedimentary structure analysis, and sand-body geometry indicate that the Buckhaults was deposited in a fluvial-deltaic environment as distributary channel and distributary mouth-bar sands. Depositional strike is northwest to southeast. The source area for the Buckhaults sediments was primarily a plutonic igneous terrane, with a minor contribution from volcanic and reworked sedimentary rocks. The proposed source area is the Amarillo-Wichita uplift to the south. In addition, the Cimarron arch and/or Keyes dome to the west-northwest may also have contributed sediment to the study area. The large (average) grain size, the amount of feldspar present, and the overall immaturity of the Buckhaults sediments indicate a relatively short distance of transport. Detailed scanning electron microscopy and x-ray diffraction analysis of cores from the productive interval coupled with comparisons of varying completion practices across the field indicate a significant correlation between individual well performance, clay mineralogy, and completion technique.

  3. Winter ecology and habitat use of lesser prairie-chickens in west Texas, 2008-11

    USGS Publications Warehouse

    Boal, Clint W.; Pirius, Nicholas E.

    2012-01-01

    The lesser prairie-chicken (Tympanuchus pallidicinctus) has experienced declines in population and occupied range by more than 90 percent since the late 1800s. The lesser prairie-chicken has been listed as a candidate species for protection under the Endangered Species Act and is undergoing review for actual listing. Populations and distribution of lesser prairie-chickens in Texas are thought to be at or near all time lows. These factors have led to substantially increased concern for conservation of the species. It is apparent that sound management and conservation strategies for lesser prairie-chickens are necessary to ensure the long-term persistence of the species. To develop those strategies, basic ecological information is required. Currently, there is a paucity of data on the wintering ecology of the species. We examined home range, habitat use, and survival of lesser prairie-chickens during the winters of 2008–9, 2009–10, and 2010–11 in sand shinnery oak (Quercus havardii) landscapes in west Texas. We captured and radio-tagged 53 adult lesser prairie-chickens. We obtained sufficient locations to estimate winter home-range size for 23 individuals. Home-range size did not differ between years or by sex. Although female prairie-chickens had slightly larger home ranges (503.5 ± 34.9 ha) compared to males (489.1 ± 34.9 ha), the differences were not significant (t2 = 0.05, P = 0.96). During the nonbreeding season, we found that 97.2 percent of locations of male and female prairie-chickens alike were within 3.2 kilometers (km) of the lek of capture. Most locations (96.8%) were within 1.7 km of a known lek and almost all locations (99.9%) were within 3.2 km of an available water source. Habitat cover types were not used proportional to occurrence within the home ranges, grassland dominated areas with sand shinnery oak were used more than available, and sand sagebrush (Artemisia filifolia) areas dominated with grassland as well as sand sagebrush areas

  4. Associations between two mosquito populations and West Nile virus in Harris County, Texas, 2003-06.

    PubMed

    Dennett, James A; Bala, Adilelkhidir; Wuithiranyagool, Taweesak; Randle, Yvonne; Sargent, Christopher B; Guzman, Hilda; Siirin, Marina; Hassan, Hassan K; Reyna-Nava, Martin; Unnasch, Thomas R; Tesh, Robert B; Parsons, Ray E; Bueno, Rudy

    2007-09-01

    Associations between Culex quinquefasciatus, Aedes albopictus and West Nile virus (WNV) activity, temperature, and rainfall in Harris County, Texas 2003-06 are discussed. Human cases were highly correlated to Cx. quinquefasciatus (r = 0.87) and Ae. albopictus (r = 0.78) pools, blue jays (r = 0.83), and Ae. albopictus collected (r = 0.71), but not Cx. quinquefasciatus collected (r = 0.45). Human cases were associated with temperature (r = 0.71), not rainfall (r = 0.29), whereas temperature correlated with Ae. albopictus and Cx. quinquefasciatus collections (r = 0.88 and 0.70, respectively) and Cx. quinqueftsciatus pools (r = 0.75), but not Ae. albopictus pools (r = 0.55). Both species (collections and pools) and blue jays were weakly correlated (r 5 0.41) with rainfall, but blue jays were better correlated with Cx. quinquefasciatus pools (r = 0.87), compared with Ae. albopictus pools (r = 0.67), Ae. albopictus collections (r = 0.69), and Cx. quinquefasciatus collections (r = 0.46). Peak minimum infection rate for Cx. quinquefasciatus (4.55), and Ae. albopictus (4.41) was in August with highest human cases (17.87), blue jays (55.58), and temperature (29.01 degrees C). Between both species, blood meal analysis indicated 68.18% of Cx. quinquefasciatus mammalian hosts were dog, while 22.72% were human, whereas Ae. albopictus had higher human (44.44%) but fewer dog hosts (22.22%). Ten bird species were identified as hosts for Cx. quinquefasciatus, with northern cardinal and blue jay representing 26.66% and 20.00%, respectively. No bird feeding activity was observed in Ae. albopictus. The earliest and latest human blood meal occurred in May (Ae. albopictus) and November (Cx. quinquefasciatus); 66.66% of human host identifications between both species occurred in October-November, after the seasonal human case peak. Based upon our data, WNV activity in both mosquito species warrants further investigation of their individual roles in WNV ecology within this region. PMID

  5. Orbital forced rhythmites in the upper Lamar Limestone (Guadalupian) of the Delaware Basin, West Texas, USA

    NASA Astrophysics Data System (ADS)

    Jin, Y.; Xuan, C.; Noble, P. J.

    2010-12-01

    Gray scale data, radiolarian relative abundance, and three types of geochemical data (oxygen isotope of bulk carbonates, organic carbon isotope, and total organic carbon) collected from an ~8 m section of the upper Lamar Limestone (Guadalupian) in the Delaware Basin, West Texas, USA, show apparent rhythms that mimic orbital variations. Spectral analyses on the radiolarian relative abundance and geochemical data, using Blackman-Tukey, multi-taper, maximum entropy, and REDFIT (Schulz, M., Mudelsee, M., 2002, REDFIT: estimating red-noise spectra directly from unevenly spaced paleoclimatic time series. Comput. Geosci. 28, 421-426) methods, reveal a common period with cycle length of ~1.16 m. Another spectral peak, which corresponds to period with cycle length of ~5.50 m, appears to be common in power spectra of the geochemical proxies. Power spectra of the high-resolution gray scale data are dominated by periods that have cycle length around 1.2-1.6 m, 0.67 m, 0.24-0.31 m, 0.14-0.18 m, and 0.07-0.09 m. Wavelet analyses confirm the existence of these cycles, and suggest that the power of the dominant periods in these parameters varies through the section, presumably due to accumulation rate variations. Average spectral misfit calculation (Meyers, S.R., Sageman, B.B., 2007, Quantification of deep-time orbital forcing by average spectral misfit. Am. J. Sci. 307, 773-792) using dominant frequencies from the power spectra of the gray scale data implies that average accumulation rates of ~1.5 cm/kyr provide the best fit of the data to orbital frequencies. Statistic tests for rejecting the null hypothesis (no orbital signal), on a wide range of average accumulation rates, also suggest lowest significance levels of the tests for accumulation rates around 1.5 cm/kyr. The ~1.5 cm/kyr accumulation rates are within the accumulation rate range estimated for the Capitanian strata in the basin-margin facies of the Delaware Basin. The Lamar Limestone appears to record the eccentricity

  6. Topographic stress perturbations in southern Davis Mountains, west Texas 1. Polarity reversal of principal stresses

    USGS Publications Warehouse

    Savage, W.Z.; Morin, R.H.

    2002-01-01

    We have applied a previously developed analytical stress model to interpret subsurface stress conditions inferred from acoustic televiewer logs obtained in two municipal water wells located in a valley in the southern Davis Mountains near Alpine, Texas. The appearance of stress-induced breakouts with orientations that shift by 90?? at two different depths in one of the wells is explained by results from exact solutions for the effects of valleys on gravity and tectonically induced subsurface stresses. The theoretical results demonstrate that above a reference depth termed the hinge point, a location that is dependent on Poisson's ratio, valley shape, and magnitude of the maximum horizontal tectonic stress normal to the long axis of the valley, horizontal stresses parallel to the valley axis are greater than those normal to it. At depths below this hinge point the situation reverses and horizontal stresses normal to the valley axis are greater than those parallel to it. Application of the theoretical model at Alpine is accommodated by the fact that nearby earthquake focal mechanisms establish an extensional stress regime with the regional maximum horizontal principal stress aligned perpendicular to the valley axis. We conclude that the localized stress field associated with a valley setting can be highly variable and that breakouts need to be examined in this context when estimating the orientations and magnitudes of regional principal stresses.

  7. Geologic and engineering characterization of Geraldine Ford field, Reeves and Culberson Counties, Texas. Topical report -- 1997

    SciTech Connect

    Dutton, S.P.; Malik, M.A.; Asquith, G.B.; Barton, M.D.; Cole, A.G.; Gogas, J.; Clift, S.J.; Guzman, J.I.

    1998-04-01

    The objective of this Class III project is to demonstrate that detailed reservoir characterization of clastic reservoirs in basinal sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost-effective way to recover more of the original oil in place by strategic infill-well placement and geologically based field development. The study focused on Geraldine Ford field, which produces from the upper Bell Canyon formation (Ramsey sandstone). Petrophysical characterization of the Ford Geraldine unit was accomplished by integrating core and log data and quantifying petrophysical properties from wireline logs. The petrophysical data were used to map porosity, permeability, net pay, water saturation, mobile oil saturation, and other reservoir properties. Once the reservoir-characterization study was completed, a demonstration area of approximately 1 mi{sup 2} in the northern part of the unit was chosen for reservoir modeling/simulation. A quarter of a five-spot injection pattern in the demonstration area was selected for flow simulations, and two cases of permeability distribution were considered, one using stochastic permeability distribution generated by conditional simulation and the other using layered permeabilities. Flow simulations were performed using UTCOMP, an isothermal, three-dimensional, compositional simulator for miscible gas flooding. Results indicate that 10--30% (1 to 3 MMbbl) of remaining oil in place in the demonstration area can be produced by CO{sub 2} injection.

  8. Application of Advanced Reservoir Characterization, Simulation, and Production Optimization Strategies to Maximize Recovery in Slope, and Basin Clastic Reservoirs, West Texas (Delaware Basin)

    SciTech Connect

    Shirley P. Dutton

    1997-04-30

    The objective of this project is to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost effective way to recover a higher percentage of the original oil in place through strategic placement of infill wells and geologically based field development. Project objectives are divided into two major phases. The objectives of the reservoir characterization phase of the project are to provide a detailed understanding of the architecture and heterogeneity of two fields, the Ford Geraldine unit and Ford West field, which produce from the Bell Canyon and Cherry Canyon Formations, respectively, of the Delaware Mountain Group and to compare Bell Canyon and Cherry Canyon reservoirs. Reservoir characterization will utilize 3-D seismic data, high-resolution sequence stratigraphy, subsurface field studies, outcrop characterization, and other techniques. Once the reservoir-characterization study of both fields is completed, a pilot area of approximately 1 mi 2 in one of the fields will be chosen for reservoir simulation. The objectives of the implementation phase of the project are to (1) apply the knowledge gained from reservoir characterization and simulation studies to increase recovery from the pilot area, (2) demonstrate that economically significant unrecovered oil remains in geologically resolvable untapped compartments, and (3) test the accuracy of reservoir characterization and flow simulation as predictive tools in resource preservation of mature fields. A geologically designed, enhanced-recovery program (CO 2 flood, waterflood, or polymer flood) and well-completion program will be developed, and one to three infill wells will be drilled and cored. Through technology transfer workshops and other presentations, the knowledge gained in the comparative study of these two fields can then be applied to increase production from the more

  9. Application of Advanced Reservoir Characterization, Simulation, and Production Optimization Strategies to Maximize Recovery in Slope and Basin Clastic Reservoirs, West Texas (Delaware Basin).

    SciTech Connect

    Dutton, S.P.

    1997-10-30

    The objective of this project is to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost effective way to recover a higher percentage of the original oil in place through strategic placement of infill wells and geologically based field development. Project objectives are divided into two major phases. The objectives of the reservoir characterization phase of the project are to provide a detailed understanding of the architecture and heterogeneity of two fields, the Ford Geraldine unit and Ford West field, which produce from the Bell Canyon and Cherry Canyon Formations, respectively, of the Delaware Mountain Group and to compare Bell Canyon and Cherry Canyon reservoirs. Reservoir characterization will utilize 3-D seismic data, high-resolution sequence stratigraphy, subsurface field studies, outcrop characterization, and other techniques. Once the reservoir- characterization study of both fields is completed, a pilot area of approximately 1 mi{sup 2} in one of the fields will be chosen for reservoir simulation. The objectives of the implementation phase of the project are to (1) apply the knowledge gained from reservoir characterization and simulation studies to increase recovery from the pilot area, (2) demonstrate that economically significant unrecovered oil remains in geologically resolvable untapped compartments, and (3) test the accuracy of reservoir characterization and flow simulation as predictive tools in resource preservation of mature fields. A geologically designed, enhanced-recovery program (CO{sub 2} flood, water flood, or polymer flood) and well-completion program will be developed, and one to three infill wells will be drilled and cored. Through technology transfer workshops and other present at ions, the knowledge gained in the comparative study of these two fields can then be applied to increase product ion

  10. Application of advanced reservoir characterization, simulation, and production optimization strategies to maximize recovery in slope and basin clastic reservoirs, West Texas (Delaware Basin). Technical progress report

    SciTech Connect

    Dutton, S.P.

    1996-04-30

    The objective of this project is to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost effective way to recover a higher percentage of the original oil in place through strategic placement of infill wells and geologically based field development. Project objectives are divided into two major phases. The objectives of the reservoir characterization phase of the project are to provide a detailed understanding of the architecture and heterogeneity of two fields, the Ford Geraldine unit and Ford West field, which produce from the Bell Canyon and Cherry Canyon Formations, respectively, of the Delaware Mountain Group and to compare Bell Canyon and Cherry Canyon reservoirs. Reservoir characterization will utilize 3-D seismic data, high-resolution sequence stratigraphy, subsurface field studies, outcrop characterization, and other techniques. One the reservoir-characterization study of both field is completed, a pilot area of approximately 1 mi{sup 2} in one of the fields will be chosen for reservoir simulation. The objectives of the implementation phase of the project are to: (1) apply the knowledge gained from reservoir characterization and simulation studies to increase recovery from the pilot area; (2) demonstrate that economically significant unrecovered oil remains in geologically resolvable untapped compartments; and (3) test the accuracy of reservoir characterization and flow simulation as predictive tools in resource preservation of mature fields. A geologically designed, enhanced recovery program (CO{sub 2} flood, waterflood, or polymer flood) and well-completion program will be developed, and one to three infill well will be drilled and cored. Technical progress is summarized for: geophysical characterization; reservoir characterization; outcrop characterization; and producibility problem characterization.

  11. Geophysical studies at proposed low-level radioactive waste disposal sites in west Texas

    SciTech Connect

    Keller, G.R.; Doser, D.I.; Whitelaw, J.; Miller, K.C.; Hua, F.; Baker, M.R.; Meeks, N. )

    1994-03-01

    Although the disposal of high-level nuclear waste is officially a national problem, the federal government has charged each state with the responsibility of disposing of its own low-level nuclear waste. Texas has considered many possible areas for its disposal facility, but has studied two sites in Hudspeth County extensively. Geophysical methods have been used to study the subsurface structure of these sites, evaluate the earthquake hazards, and set up monitoring of possible leakage from the sites. The structural studies employed the same techniques as used in petroleum exploration, but with a ore balanced reliance between seismic and potential field methods. Since the scale of these investigations was relatively small (a few miles in extent), high-resolution methodology was employed. This aspect of the project mainly impacted the seismic reflection work. The depth to the bedrock was a major concern because the near-surface alluvium is generally a good natural barrier to any potential leakage. The location of any faults near the sites was also a major concern, because faults were both an indicator of potential earthquake hazards and a possible pathway for rapid movement of any material that might leak from the site. Analysis of the tectonic stability of the site involved regional geophysical data on a crustal scale and an evaluation of the historical earthquake record. A network of seismograph stations was established in the region to monitor contemporary seismicity. Compared to typical petroleum applications of geophysical data, these studies involved a wide variety of data and an analysis that required the methodical integration of these data.

  12. Irrigation with Treated Urban Wastewater for Bioenergy Crop Production in the Far West Texas

    NASA Astrophysics Data System (ADS)

    Ganjegunte, G. K.; Clark, J. A.; Wu, Y.

    2011-12-01

    In the recent years, interest in biobased fuels is increasing and the congressionally mandated goal is to use at least 36 billion gallons of bio-based transportation fuels by 2022. However, in 2009 the U.S. produced about 10.75 billion gallons of ethanol, primarily as corn starch ethanol and 550 million gallons of biodiesel. Thus, there is a huge gap between the current capacity and the mandated goal. USDA estimates that about 27 million acres of land has to be brought under bioenergy crops to produce 36 billion gallons of bio-based fuels. Meeting the challenge of bridging this huge gap requires a comprehensive regional strategy that includes bringing addition area from different regions within the country under bioenergy crops. In the southwest U.S. region such as west Texas or southern New Mexico, bringing vast abandoned crop lands and areas having permeable soils under bioenergy crops can be a part of such a regional strategy. While the region has adequate supply of land, finding reliable source of water to produce bioenergy crops is the main challenge. This challenge can be met by developing marginal quality water sources for bioenergy crops production. Use of marginal quality waters such as treated urban wastewater/saline groundwater to irrigate bioenergy crops may prove beneficial, if the bioenergy crops can grow under elevated salinity and the effects on soil and shallow groundwater can be minimized by appropriate management. The region has enormous potential for marginal quality water irrigation to produce bioenergy crops for a greater farm return. For example, at present, in El Paso alone, the total volume of treated municipal and industrial wastewater is about 65,000 acre-feet/year, of which only 13% is being reused for industrial processes and irrigating urban landscapes. The major concern associated with treated wastewater irrigation is its salinity (electrical conductivity or EC which measures salinity ranges from 1.8 to 2.1 dS m-1) and sodicity

  13. Incidense of spider mites in South Texas cotton fields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The incidence of spider mites was evaluated· in four locations of south Texas between Progreso (Hidalgo Co.) to Bishop (Nueces Co.). This is an area with a south to north transect of 125 miles from south Progreso to north Bishop (respectively).The other two intermediate sampled locations were Harlin...

  14. Employing spatial information technologies to monitor biological control of saltcedar in West Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The saltcedar leaf beetle (Diorhadha spp.) has shown promise as a biocontrol agent for saltcedar (Tamarix spp.) invasions in the United States. In Texas, natural resource managers need assistance in monitoring biological control of invasive saltcedars. This study describes application of a medium fo...

  15. Applying broadband spectra to assess biological control of saltcedar in West Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In Texas, natural resource managers, government officials, and scientists need effective means for monitoring biological control of saltcedar (Tamarix spp.) with the saltcedar leaf beetle (Diorhadba spp.). This study was conducted to evaluate broadband spectra within visible, red-edge, and near-inf...

  16. Creating a disease risk map for West Nile virus for surveillance in Central Texas using a Geographic Information System and Remote Sensing technologies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Following the discovery of the West Nile virus (WNv) in Brazos County, TX in 2002, mosquito research personnel at Texas A&M University established a routine WNv mosquito vector surveillance program in the county. In 2004, a map of Brazos County was created depicting areas that had a heightened leve...

  17. Precambrian basement geology of the Permian basin region of west Texas and Eastern New Mexico: A geophysical perspective

    SciTech Connect

    Adams, D.C.; Keller, G.R.

    1996-03-01

    Because most of the Permian basin region of west Texas and southern New Mexico is covered by Phanerozoic rocks, other means must be found to examine the Precambrian upper crustal geology of the region. We have combined geologic information on the Precambrian from outcrops and wells with geophysical information from gravity and magnetic surveys in an integrated analysis of the history and structure of basement rocks in the region. Geophysical anomalies can be related to six Precambrian events: formation of the Early Proterozoic outer tectonic belt, igneous activity in the southern Granite-Rhyolite province, an episode of pre-Grenville extension, the Grenville orogeny, rifting to form the Delaware aulacogen, and Eocambrian rifting to form the early Paleozoic continental margin. Two geophysical features were studied in detail: the Abilene gravity minimum and the Central Basin platform gravity high. The Abilene gravity minimum is shown to extend from the Delaware basin across north-central Texas and is interpreted to be caused by a granitic batholith similar in size to the Sierra Nevada batholith in California and Nevada. This batholith appears to be related to formation of the southern Granite- Rhyolite province, possibly as a continental margin arc batholith. Because of this interpretation, we have located the Grenville tectonic front southward from its commonly quoted position, closer to the Llano uplift. Middle Proterozoic mafic intrusions are found to core the Central Basin platform and the Roosevelt uplift. These intrusions formed at about 1.1 Ga and are related in time to both the Mid-Continent rift system and the Grenville orogeny in Texas. Precambrian basement structures and changes in lithology have influenced the structure and stratigraphy in the overlying Permian basin, and thus have potential exploration significance.

  18. Middle proterozoic tectonic activity in west Texas and eastern New Mexico and analysis of gravity and magnetic anomalies

    SciTech Connect

    Adams, D.C.; Keller, G.R. )

    1994-03-01

    The Precambrian history of west Texas and eastern New Mexico is complex, consisting of four events: Early Proterozoic orogenic activity (16309-1800 Ma), formation of the western granite-rhyolite province (WGRP) (1340-1410 Ma), Grenville age tectonics (1116-1232 Ma), and middle Proterozoic extension possibly related to mid-continent rifting (1086-1109 Ma). Pre-Grenville tectonics, Grenville tectonics, and mid-continent rifting are represented in this area by the Abilene gravity minimum (AGM) and bimodal igneous rocks, which are probably younger. We have used gravity modeling and the comparison of gravity and magnetic anomalies with rock types reported from wells penetrating Precambrian basement to study the AGM and middle Proterozoic extension in this area. The AGM is an east-northeast-trending, 600 km long, gravity low, which extends from the Texas-Oklahoma border through the central basin platform (CBP) to the Delaware basin. This feature appears to predate formation of the mafic body in the CBP (1163 Ma) and is most likely related to Pre-Grenville tectonics, possibly representing a continental margin arc batholith. Evidence of middle Proterozoic extension is found in the form of igneous bodies in the CBP, the Van Horn uplift, the Franklin Mountains, and the Sacramento Mountains. Analysis of gravity and magnetic anomalies shows that paired gravity and magnetic highs are related to mafic intrusions in the upper crust. Mapping of middle Proterozoic igneous rocks and the paired anomalies outlines a 530 km diameter area of distributed east-west-oriented extension. The Debaca-Swisher terrain of shallow marine and clastic sedimentary rocks is age correlative with middle Proterozoic extension. These rocks may represent the lithology of possible Proterozoic exploration targets. Proterozoic structures were reactivated during the Paleozoic, affecting both the structure and deposition in the Permian basin.

  19. View of sports field and Easter Hill at west side ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of sports field and Easter Hill at west side of project site. Looking southwest - Easter Hill Village, Bordered by South Twenty-sixth Street, South Twenty-eighth Street, Hinkley Avenue, Foothill Avenue & Corto Square, Richmond, Contra Costa County, CA

  20. A health survey of a colonia located on the west Texas, US/Mexico border.

    PubMed

    Anders, Robert L; Olson, Thomas; Robinson, Kris; Wiebe, John; DiGregorio, Rena; Guillermina, Mina; Albrechtsen, Justin; Bean, Nathaniel H; Ortiz, Melchor

    2010-06-01

    Little is known about how health disparities affect the health status and general health perceptions of Hispanics living in Texas colonias. The purpose of this study was to conduct a health survey of residents (n = 216) of a colonia community on the border between El Paso, Texas and Juarez, Mexico. Instruments used in this study included a researcher developed demographic questionnaire, the Short Acculturation Scale for Hispanics (SASH), Cutting down, Annoyance by criticism, Guilty feeling and Eye-openers (CAGE) for alcohol consumption, and the Short Form version 2 (SF36v2) health survey. Study findings show the average participant was approximately 42 years old, attained an average of 9.6 years of education, earned an average annual household income of $17,575 and had an average SASH score of 25.4. SASH scores range from 12 to 60, with higher scores suggesting higher levels of American acculturation. Findings from this health survey suggest the average resident of the colonia may have health disadvantages when compared to residents from other parts of El Paso and Texas. Binge drinking was self-reported by 13.4% of all participants; with 5.6% having a CAGE score greater than 2 (indicating an increased propensity towards problems with alcohol). The self-report rates of diabetes, depression and anxiety were 15.3%, 20.4% and 16.7% respectively. The SF36v2 composite functional health status scores mirrored the national norms. PMID:18791825

  1. Improving polymer injectivity at West Coyote Field, California

    SciTech Connect

    Shuler, P.J.; Kuehne, D.L.; Uhl, J.T.; Walkup, G.W.

    1985-03-01

    This paper presents a case history where laboratory and simulation results were used to model a single-well polymer injectivity field test in the West Coyote Field and improve the injectivity in a subsequent field test. The polyacrylamide polymer used in the first test exhibited low injectivity. Laboratory studies were performed to identify the causes of low injectivity and physically model the field test. Laboratory core data and reservoir properties were used in a mathematical model to calculate the polymer injectivity, which closely matched that observed in the field. The low polymer injectivity at West Coyote was due to: formation damage caused by the polymer and low salinity polymer makeup water; and the high resistance factor developed by the polymer. These problems were overcome by: using a lower molecular weight polyacrylamide; preshearing the polymer solution before injection; and increasing the salinity of the polymer makeup water. These improvements resulted in a 50% increase in injectivity during the second polymer injectivity field test at West Coyote.

  2. Improving polymer injectivity at West Coyote Field, California

    SciTech Connect

    Shuler, P.J.; Kuchne, D.L.; Uhl, J.T.; Walkup, G.W.

    1987-08-01

    This paper presents a case history where laboratory and simulation results were used to model a single-well polymer injectivity field test in the West Coyote field and to improve injectivity in a subsequent field test. The polyacrylamide used in the first test exhibited low injectivity. Laboratory studies were performed to identify the causes of low injectivity and to model the field test physically. Laboratory core data and reservoir properties were used in a mathematical model to calculate the polymer injectivity, which closely matched that observed in the field. The low polymer injectivity at West Coyote was a result of formation damage caused by the polymer and low-salinity polymer makeup water and the high resistance factor developed by the polymer. These problems were overcome by using a lower-molecular-weight polyacrylamide, preshearing the polymer solution before injection, and increasing the salinity of the polymer makeup water. These improvements resulted in a 50% increase in injectivity during the second polymer injectivity field test at West Coyote.

  3. Application of Advanced Reservoir Characterization, Simulation, and Production Optimization Strategies to Maximize Recovery in Slope and Basin Clastic Reservoirs, West Texas (Delaware Basin)

    SciTech Connect

    Dutton, S.P.; Flanders, W.A.; Guzman, J.I.; Zirczy, H.

    1999-06-08

    The objective of this Class III project is to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost-effective way to recover a higher percentage of the original oil in place through geologically based field development. This year the project focused on reservoir characterization of the East Ford unit, a representative Delaware Mountain Group field that produces from the upper Bell Canyon Formation (Ramsey Sandstone). The field, discovered in 1960, is operated by Orla Petco, Inc., as the East Ford unit; it contained an estimated 19.8 million barrels (MMbbl) of original oil in place. Petrophysical characterization of the East Ford unit was accomplished by integrating core and log data and quantifying petrophysical properties from wireline logs. Most methods of petrophysical analysis that had been developed during an earlier study of the Ford Geraldine unit were successfully transferred to the East Ford unit. The approach that was used to interpret water saturation from resistivity logs, however, had to be modified because in some East Ford wells the log-calculated water saturation was too high and inconsistent with observations made during the actual production. Log-porosity to core-porosity transforms and core-porosity to core-permeability transforms were derived from the East Ford reservoir. The petrophysical data were used to map porosity, permeability, net pay, water saturation, mobil-oil saturation, and other reservoir properties.

  4. Application of integrated remote sensing and GIS technologies to geoenvironmental issues in far west Texas and southern New Mexico

    NASA Astrophysics Data System (ADS)

    Perez, Adriana Evangelina

    The primary goal of this dissertation was to utilize a geographic information system (GIS) to better understand geological, geophysical, forestry and environmental issues in the west Texas-New Mexico region. Studies such as these are especially important in the border region where economic limitations are usually a factor in studying and solving some of these problems. The availability of satellite imagery through the Pan-American Center for Earth and Environmental Studies (PACES), data from the Geospatial Center and the collaboration with the United States Department of Agriculture (USDA) and National Forest entities (Guadalupe and Lincoln Ranger Districts) enhance the value of our investigation. Research was conducted in two distinct areas: Cloudcroft-Ruidoso, New Mexico, and the Salt Flat basin of southwest Texas (Figure 1). The dissertation will be presented as a set of independent chapters. Chapter 1. A GIS and remote sensing investigation of the effects of interactions of terrain, soil, and other physiographic factors on the Pine Community of Lincoln National Park in the Sacramento Mountains of Southwest New Mexico. This study utilized GIS and remote sensing to better understand the dynamics of White Pine Blister Rust (WPBR) infestation in the white pine community of the Sacramento Mountains of southwest New Mexico. Both field spectral sampling of the needles and imagery analysis were incorporated to better understand the infestation, progression and vulnerability of the forest to this and other diseases. A major contribution of this study was to construct a GIS database, which was utilized to analyze USDA, elevation, satellite imagery, geological, and hydrological data to produce a hazard-rating map. The GIS environment also allowed for a 3-D perspective on the data, which was very useful in spatial visualization. Chapter 2. An integrated study of the basin structure of the Salt Flat basin. In this study we utilized, gravity and magnetic data, satellite

  5. Texas as seen from the Apollo 6 unmanned spacecraft

    NASA Technical Reports Server (NTRS)

    1968-01-01

    Texas is photographed from the Apollo 6 (Spacecraft 020/Saturn 502) unmanned space mission. Seen in this photograph are Midland, Brownfield, Big Spring, J.B.Thomas Lake, headwaters of Colorado and Brazos Rivers, and the west Texas gas and oil fields.

  6. Late Leonardian plants from West Texas: The youngest Paleozoic plant megafossils in North America

    USGS Publications Warehouse

    Mamay, S.H.; Miller, J.M.; Rohr, D.M.

    1984-01-01

    Abundant Permian plant megafossils were discovered in the Del Norte Mountains of Brewster County, Trans-Pecos Texas. The flora is dominated by a new and distinctive type of gigantopteroid leaves. Marine invertebrates are closely associated, and this admixture of continental and marine fossils indicates a deltaic depositional setting, probably on the southern margin of the Permian Basin. Conodonts indicate correlation with the uppermost Leonardian Road Canyon Formation in the Glass Mountains. These are the youngest Paleozoic plant megafossils known in North America; they add an important paleontological element to the classic Permian area of this Continent.

  7. Application of Advanced Reservoir Characterization, Simulation, and Production Optimization Strategies to Maximize Recovery in Slope and Basin Clastic Reservoirs, West Texas (Delaware Basin)

    SciTech Connect

    Andrew G. Cole; George B. Asquith; Jose I. Guzman; Mark D. Barton; Mohammad A. Malik; Shirley P. Dutton; Sigrid J. Clift

    1998-04-01

    The objective of this Class III project is to demonstrate that detailed reservoir characterization of clastic reservoirs in basinal sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost-effective way to recover more of the original oil in place by strategic infill-well placement and geologically based enhanced oil recovery. The study focused on the Ford Geraldine unit, which produces from the upper Bell Canyon Formation (Ramsey sandstone). Reservoirs in this and other Delaware Mountain Group fields have low producibility (average recovery <14 percent of the original oil in place) because of a high degree of vertical and lateral heterogeneity caused by depositional processes and post-depositional diagenetic modification. Outcrop analogs were studied to better interpret the depositional processes that formed the reservoirs at the Ford Geraldine unit and to determine the dimensions of reservoir sandstone bodies. Facies relationships and bedding architecture within a single genetic unit exposed in outcrop in Culberson County, Texas, suggest that the sandstones were deposited in a system of channels and levees with attached lobes that initially prograded basinward, aggraded, and then turned around and stepped back toward the shelf. Channel sandstones are 10 to 60 ft thick and 300 to 3,000 ft wide. The flanking levees have a wedge-shaped geometry and are composed of interbedded sandstone and siltstone; thickness varies from 3 to 20 ft and length from several hundred to several thousands of feet. The lobe sandstones are broad lens-shaped bodies; thicknesses range up to 30 ft with aspect ratios (width/thickness) of 100 to 10,000. Lobe sandstones may be interstratified with laminated siltstones.

  8. Paleokarst, karst related diagenesis and reservoir development: Examples from Ordovician-Devonian age strata of west Texas and the Mid-continent

    SciTech Connect

    Candelaria, M.P.; Reed, C.L.

    1992-01-01

    This publication served as a guidebook for a Permian Basin Section-SEPM field trip to examine exposures of paleokarst in lower Paleozoic platform carbonates of West Texas and New Mexico. Included are road logs for the field trips and a collection of eighteen papers and abstracts that focus on various aspects of paleokarst in shallow-water carbonates including: (1) recognition and classification of karst-related textures in outcrop and the subsurface; (2) sequence stratigraphic analysis of karsted platforms; (3) diagenetic products of karstification; and (4) production characteristics of karst reservoirs. Collectively, these papers provide excellent documentation of sedimentary fabrics and diagenetic products associated with paleokarst development resulting from regional exposure of Cambro-Ordovician and Siluro-Devonian carbonates of the Great American Bank.'' The major value of this volume lies in the integration of a variety of approaches for examining processes and products related to karstification. These include the use of core, outcrop, well logs, and computer modeling to better understand paleokarst development and preservation. Some of the more interesting articles are highlighted below.

  9. Geoscience/engineering characterization of the interwell environment in carbonate reservoirs based on outcrop analogs, Permian Basin, West Texas and New Mexico - petrophysical characterization of the South Cowden Grayburg Reservoir, Ector County, Texas. Final report

    SciTech Connect

    Lucia, F.J.

    1997-06-01

    Reservoir performance of the South Cowden Grayburg field suggests that only 21 percent of the original oil in place has been recovered. The purpose of this study is to construct a realistic reservoir model to be used to predict the location of the remaining mobile oil. Construction of reservoir models for fluid-flow simulation of carbonate reservoirs is difficult because they typically have complicated and unpredictable permeability patterns. Much of the difficulty results from the degree to which diagenetic overprinting masks depositional textures and patterns. For example, the task of constructing a reservoir model of a limestone reservoir that has undergone only cementation and compaction is easier than constructing a model of a karsted reservoir that has undergone cavern formation and collapse as well as cementation and compaction. The Permian-age carbonate-ramp reservoirs in the Permian Basin, West Texas and New Mexico, are typically anhydritic dolomitized limestone. Because the dolomitization occurred soon after deposition, depositional fabrics and patterns are often retained, and a reservoir model can be constructed using depositional concepts. Recent studies of the San Andres outcrop in the Guadalupe Mountains and the Seminole San Andres reservoir in the Permian Basin illustrate how depositional fabrics and patterns can be used to construct a reservoir model when depositional features are retained.

  10. An unusual Middle Permian flora from the Blaine Formation (Pease River Group: Leonardian-Guadalupian Series) of King County, West Texas

    USGS Publications Warehouse

    DiMichele, W.A.; Hook, R.W.; Nelson, W.J.; Chaney, D.S.

    2004-01-01

    A new Middle Permian plant assemblage from South Ash Pasture in King County, Texas, may be the youngest and is certainly the most unusual flora known from the Permian of either West Texas or adjoining north-central Texas. Found serendipitously in the evaporite-rich upper Blaine Formation (Pease River Group, Guadalupian Series), the flora is of very low diversity despite intensive collecting efforts, and the affinities of nearly all taxa are enigmatic. The most common elements are parallel-veined leaves that resemble cordaites but that could be isolated pinnules of a pinnate leaf. Gigantopterid foliage is present but not assignable to any known taxon. A single foliar conifer specimen is too incomplete for assignment. Numerous reproductive organs, however, and an abundance of axes may represent conifers. Conchostracans, palaeoniscoid fish scales, and small heteropolar coprolites also occur in the deposit, which originated as a small, claystone-dominated channel fill in a coastal plain setting.

  11. A multidiscipline look at the Thistle field area, Pecos County, Texas

    SciTech Connect

    Land, J.P. )

    1992-04-01

    To allow an evaluation of the perspective provided by certain nonseismic methods in the Val Verde basin, the synergistic interpretation of gravimetric and magnetic data, surface geomorphology, and the Ellenburgger surface are compared to surface geochemical data and drilling immediate to the Thistle field, Pecos County, Texas.

  12. Investigations of a deep drill hole in the Ouachita tend, west Texas

    SciTech Connect

    Borrego, P.M.; Moreno, F.; Keller, G.R.; Marsaglia, K.M.; Pingitore, N.E. )

    1994-03-01

    The Exxon 1 Gatlin well was recently drilled to a depth of over 25,000 ft in Terrell County, Texas, just north of the international boundary with Mexico. This well is deepest penetration of the interior zone of the Ouachita system to data. The well is near the apex of the interior zone gravity high, which elsewhere has been shown to approximately mark the Paleozoic continental margin. Gravity models constructed in this region, including one that was tied to this well, confirm that this well is proximal to the Paleozoic margin. The well was spudded in Lower Cretaceous rocks, and drilled through a 23,000-ft section of low-grade metamorphic rocks. Cuttings of this metamorphic section are composed predominantly of phyllite, fine-grained schist, metaquartzite, and impure marble. Based on their mineralogy and texture, the likely precursor for these rocks was a sedimentary sequence of marls and mudstones. However, no relict sedimentary structures or fauna was observed. Phyllite and schist fragments are graphitic and locally crenulated, and large fragments exhibit multiple phases of deformation. Minor coarse carbonate and quartz may represent vein fills. Downhole textural trends include a gradual change from phyllite to schist at approximately 7500 ft. and a gradual increase in schist fragments to 19,600 ft. X-ray diffraction of bulk samples indicates a downhole decrease in total carbonate content. This metamorphic sequence appears similar to Ouachita interior zone rocks encountered in wells in central Texas and in outcrops in Oklahoma and Arkansas. However, the large thickness encountered in the well and the even larger thickness suggested by the gravity modeling is indicative of proximity to the continental margin and is likely the result of thrust faulting.

  13. Did CO2 injection induce 2006-2011 earthquakes in the Cogdell oil field, Texas?

    NASA Astrophysics Data System (ADS)

    GAN, W.; Frohlich, C.

    2013-12-01

    as a strategy for managing climate change. 1. Davis SD, Pennington WD (1989) Induced seismic deformation in the Cogdell oil field of west Texas. Bull Seismol Soc Amer 79:1477-1495.

  14. The unusual 3D interplay of basement fault reactivation and fault-propagation-fold development: A case study of the Laramide-age Stillwell anticline, west Texas (USA)

    NASA Astrophysics Data System (ADS)

    Surpless, Ben; Hill, Nicola; Beasley, Cara

    2015-10-01

    Subsurface fault geometries have a systematic influence on folds formed above those faults. We use the extraordinarily well-exposed fold geometries of the Laramide-age Stillwell anticline in west Texas (USA) to develop a strain-predictive model of fault-propagation fold formation. The anticline is a 10-km long, NW-trending, NE-vergent, asymmetric fold system with an axis that displays a map-view left-stepping, en echelon pattern. We integrated field observations, geologic and structural data, cross-sections, and 2D kinematic modeling to establish an unusual 3D two-stage model of contractional fold formation, including: 1) reverse reactivation of a pre-existing, NW-striking, SW-dipping, left-stepping, en echelon normal fault system in Paleozoic basement rocks to generate monoclinal flexures in overlying layered Cretaceous carbonate rocks; and 2) the formation of a subsequent flat-ramp fault system that propagated horizontally along a mechanically-weak, clay-rich Cretaceous unit before ramping up at the hinge of the pre-existing monocline system. Strain is focused within the forelimb of the system, in front of the propagating fault tip, and is accommodated by a combination of interlayer slip, flat-ramp faulting, and fracturing proximal to planes of slip. This strain predictive model can be applied to similar, less-well-exposed contractional systems worldwide and provides a new, unusual example of Laramide-age contractional deformation.

  15. Morrowan sedimentation in the Orogrande basin, west Texas and south-central New Mexico

    SciTech Connect

    Connolly, W.M.; Stanton, R.J. Jr.

    1986-03-01

    Morrowan strata in the Hueco and Franklin Mountains reflect deposition within a shallow, gradually subsiding, carbonate shelf lagoon. Postulated environments fluctuated between open shelf lagoon with localized shoaling, restricted inner shelf lagoon, and peritidal settings. Variations in depth were slight, probably not exceeding several tens of meters within the photic zone. The La Tuna Formation (Franklin Mountains) was deposited near the axis (center) of the Orogrande basin; the lower division of the Magdalena limestone (Hueco Mountains), 30 mi east, was deposited 20-30 mi west of the paleoshoreline. Physiographically, the Orogrande sea was a small gulf, offering a certain degree of protection from the Morrowan seaway to the south. Sedimentologically, it was a wide expanse of predominantly quiet-water carbonate sedimentation with subordinate argillaceous influex and coarser peripheral clastics. The Orogrande basin, a stratigraphic feature, corresponds to a blanket deposit of shallow epeiric carbonates. Climatic and orographic effects are invoked to explain the contrasting style of clastic sedimentation in the Delaware and orogrande basins, east and west of the Pedernal uplift. Analysis of Morrowan carbonates reveals no evidence of cyclicity, major transgressions or regressions, or local tectonic activity. Deposition was stable and in equilibrium with a gradually subsiding shallow basin. Based on lithologic, faunal, biostratigraphic, and paleogeographic criteria, the lower division is both laterally and temporally equivalent with the La Tuna Formation. Accordingly, the latter term is advocated in favor of the former, which lacks both priority and formal status.

  16. Associations between water physicochemistry and Prymnesium parvum presence, abundance, and toxicity in west Texas reservoirs

    USGS Publications Warehouse

    VanLandeghem, Matthew M.; Farooqi, Mukhtar; Southard, Greg M.; Patino, Reynaldo

    2015-01-01

    Toxic blooms of golden alga (Prymnesium parvum) have caused substantial ecological and economic harm in freshwater and marine systems throughout the world. In North America, toxic blooms have impacted freshwater systems including large reservoirs. Management of water chemistry is one proposed option for golden alga control in these systems. The main objective of this study was to assess physicochemical characteristics of water that influence golden alga presence, abundance, and toxicity in the Upper Colorado River basin (UCR) in Texas. The UCR contains reservoirs that have experienced repeated blooms and other reservoirs where golden alga is present but has not been toxic. We quantified golden alga abundance (hemocytometer counts), ichthyotoxicity (bioassay), and water chemistry (surface grab samples) at three impacted reservoirs on the Colorado River; two reference reservoirs on the Concho River; and three sites at the confluence of these rivers. Sampling occurred monthly from January 2010 to July 2011. Impacted sites were characterized by higher specific conductance, calcium and magnesium hardness, and fluoride than reference and confluence sites. At impacted sites, golden alga abundance and toxicity were positively associated with salinity-related variables and blooms peaked at ~10°C and generally did not occur above 20°C. Overall, these findings suggest management of land and water use to reduce hardness or salinity could produce unfavorable conditions for golden alga.

  17. Sequence stratigraphic model of the Rio Grande Delta, south west Texas: Potential analog for the Niger Delta

    SciTech Connect

    Banfield, L.A.; Anderson, J.B.; Vail, P.R. )

    1996-01-01

    A sequence stratigraphic model developed from the ancient Rio Grande Delta in South West Texas is suggested as an analog for the Niger Delta. The two delta systems are characterized by high sand bedloads, shale diapirism with associated listric normal faulting, and large amounts of tidal and wave influence forming lower coastal plains characterized by swamps and estuaries. The sequence stratigraphic model of the ancient Rio Grande delta is based on approximately 1200 kilometers of single channel, 15 cubic inch water gun data, lithologic descriptions from approximately 25 long cores (28-30 m) located in 17-94 meters water depth, three gamma ray logs, paleontologic data from two cores, and oxygen isotopic data from one core (152 meters in length and located in 94 meters water depth). The combined data indicate that considerable quantities of sand are sequestered on the continental shelf and point sourcing the slope. The Rio Grande sequence stratigraphic model provides an improved understanding of sand deposits on the shelf, of the role of sediment bypass during lowstands, and of the base of slope deposits formed by headward eroding canyons ( ) or channels ( ) located at the shelf break. This information regarding the distribution of sand in the Rio Grande system can provide valuable insight into the reservoir distribution in the Niger system, improving existing reservoir predictions.

  18. Sequence stratigraphic model of the Rio Grande Delta, south west Texas: Potential analog for the Niger Delta

    SciTech Connect

    Banfield, L.A.; Anderson, J.B.; Vail, P.R.

    1996-12-31

    A sequence stratigraphic model developed from the ancient Rio Grande Delta in South West Texas is suggested as an analog for the Niger Delta. The two delta systems are characterized by high sand bedloads, shale diapirism with associated listric normal faulting, and large amounts of tidal and wave influence forming lower coastal plains characterized by swamps and estuaries. The sequence stratigraphic model of the ancient Rio Grande delta is based on approximately 1200 kilometers of single channel, 15 cubic inch water gun data, lithologic descriptions from approximately 25 long cores (28-30 m) located in 17-94 meters water depth, three gamma ray logs, paleontologic data from two cores, and oxygen isotopic data from one core (152 meters in length and located in 94 meters water depth). The combined data indicate that considerable quantities of sand are sequestered on the continental shelf and point sourcing the slope. The Rio Grande sequence stratigraphic model provides an improved understanding of sand deposits on the shelf, of the role of sediment bypass during lowstands, and of the base of slope deposits formed by headward eroding canyons (?) or channels (?) located at the shelf break. This information regarding the distribution of sand in the Rio Grande system can provide valuable insight into the reservoir distribution in the Niger system, improving existing reservoir predictions.

  19. Use of the routing procedure to study dye and gas transport in the West Fork Trinity River, Texas

    USGS Publications Warehouse

    Jobson, Harvey E.; Rathbun, R.E.

    1984-01-01

    Rhodamine-WT dye, ethylene, and propane were injected at three sites along a 21.6-kilometer reach of the West Fork Trinity River below Fort Worth, Texas. Complete dye concentration versus time curves and peak gas concentrations were measured at three cross sections below each injection. The peak dye concentrations were located and samples were collected at about three-hour intervals for as many as six additional cross sections. These data were analyzed to determine the longitudinal dispersion coefficients as well as the gas desorption coefficients using both standard techniques and a numerical routing procedure. The routing procedure, using a Lagrangian transport model to minimize numerical dispersion, provided better estimates of the dispersion coefficient than did the method of moments. At a steady flow of about 0.76 m2/s, the dispersion coefficient varied from about 0.7 m2/s in a reach contained within a single deep pool to about 2.0 m2/s in a reach containing riffles and small pools. The bulk desorption coefficients computed using the routing procedure and the standard peak method were essentially the same. The liquid film coefficient could also be obtained using the routing procedure. Both the bulk desorption coefficient and the liquid film coefficient were much smaller in the pooled reach than in the reaches containing riffles.

  20. 300-Myr-old magmatic CO2 in natural gas reservoirs of the west Texas Permian basin.

    PubMed

    Ballentine, C J; Schoell, M; Coleman, D; Cain, B A

    2001-01-18

    Except in regions of recent crustal extension, the dominant origin of carbon dioxide in fluids in sedimentary basins has been assumed to be from crustal organic matter or mineral reactions. Here we show, by contrast, that Rayleigh fractionation caused by partial degassing of a magma body can explain the CO2/3He ratios and delta13C(CO2) values observed in CO2-rich natural gases in the west Texas Val Verde basin and also the mantle 3He/22Ne ratios observed in other basin systems. Regional changes in CO2/3He and CO2/CH4 ratios can be explained if the CO2 input pre-dates methane generation in the basin, which occurred about 280 Myr ago. Uplift to the north of the Val Verde basin between 310 and 280 Myr ago appears to be the only tectonic event with appropriate timing and location to be the source of the magmatic CO2. Our identification of magmatic CO2 in a foreland basin indicates that the origin of CO2 in other mid-continent basin systems should be re-evaluated. Also, the inferred closed-system preservation of natural gas in a trapping structure for approximately 300 Myr is far longer than the residence time predicted by diffusion models. PMID:11201738

  1. 5. East side of quarters (executive officer's quarters), looking west ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. East side of quarters (executive officer's quarters), looking west - Naval Air Station Chase Field, Quarters S, Essex Street, .45 mile South-Southeast of intersection of Texas State Highway 202 & Independence Street, Beeville, Bee County, TX

  2. 3. East side of Building 1001 (administration building), looking west ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. East side of Building 1001 (administration building), looking west - Naval Air Station Chase Field, Building 1001, Independence Street, .45 mile south of intersection of Texas State Highway & Independence Street, Beeville, Bee County, TX

  3. 6. West side of Building 1001 (administration building), looking southeast ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. West side of Building 1001 (administration building), looking southeast - Naval Air Station Chase Field, Building 1001, Independence Street, .45 mile south of intersection of Texas State Highway & Independence Street, Beeville, Bee County, TX

  4. 2. West side of quarters (executive officer's quarters), looking east ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. West side of quarters (executive officer's quarters), looking east - Naval Air Station Chase Field, Quarters S, Essex Street, .45 mile South-Southeast of intersection of Texas State Highway 202 & Independence Street, Beeville, Bee County, TX

  5. 9. Interior of Building 1040 (gym), looking west Naval ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. Interior of Building 1040 (gym), looking west - Naval Air Station Chase Field, Building 1040, Enterprise Street, .37 mile South-Southeast of intersection of Texas State Highway 202 & Independence Street, Beeville, Bee County, TX

  6. Geoscience/engineering characterization of the interwell environment in carbonate reservoirs based on outcrop analogs, Permian Basin, West Texas and New Mexico--waterflood performance analysis for the South Cowden Grayburg Reservoir, Ector County, Texas. Final report

    SciTech Connect

    Jennings, J.W. Jr.

    1997-05-01

    A reservoir engineering study was conducted of waterflood performance in the South Cowden field, an Upper Permian Grayburg reservoir on the Central Basin Platform in West Texas. The study was undertaken to understand the historically poor waterflood performance, evaluate three techniques for incorporating petrophysical measurements and geological interpretation into heterogeneous reservoir models, and identify issues in heterogeneity modeling and fluid-flow scaleup that require further research. The approach included analysis of relative permeability data, analysis of injection and production data, heterogeneity modeling, and waterflood simulation. The poor South Cowden waterflood recovery is due, in part, to completion of wells in only the top half of the formation. Recompletion of wells through the entire formation is estimated to improve recovery in ten years by 6 percent of the original oil in place in some areas of the field. A direct three-dimensional stochastic approach to heterogeneity modeling produced the best fit to waterflood performance and injectivity, but a more conventional model based on smooth mapping of layer-averaged properties was almost as good. The results reaffirm the importance of large-scale heterogeneities in waterflood modeling but demonstrate only a slight advantage for stochastic modeling at this scale. All the flow simulations required a reduction to the measured whole-core k{sub v}/k{sub h} to explain waterflood behavior, suggesting the presence of barriers to vertical flow not explicitly accounted for in any of the heterogeneity models. They also required modifications to the measured steady-state relative permeabilities, suggesting the importance of small-scale heterogeneities and scaleup. Vertical flow barriers, small-scale heterogeneity modeling, and relative permeability scaleup require additional research for waterflood performance prediction in reservoirs like South Cowden.

  7. Water-quality of Lake Conroe on the west fork San Jacinto River, Southeastern Texas

    USGS Publications Warehouse

    Flugrath, M.W.; Andrews, F.L.; McPherson, Emma

    1985-01-01

    Thermal stratification in Lake Conroe, Texas usually begins to develop in March and persists until October. Thermal stratification has resulted in significant seasonal and areal variations in the concentrations of dissolved oxygen, dissolved iron, dissolved manganese, total inorganic nitrogen, and total phosphorus. Volume-weighted-average concentration of dissolved solids generally was < 120 mg/L, that of dissolved chloride generally was < 22 mg/L, and that of dissolved sulfate was < 10 mg/L in Lake Conroe during the 1973-82 water years. The concentrations of each of these constituents usually were largest during the summer. The water was moderately hard (hardness > 60 but < 120 mg/L as calcium carbonate). The average concentrations of dissolved oxygen at most sites in the downstream one-half of the lake averaged 3.2 mg/L during summer stratification and > 9 mg/L during winter circulation. The concentrations at most sites in the headwaters of the lake averaged < 4.3 mg/L during the summer and < 7.9 mg/L during the winter. Water below depths of 25 to 35 ft usually contained < 1 mg/L dissolved oxygen during the summer. The concentrations of dissolved iron and dissolved manganese in water throughout the reservoir during winter circulation and in water near the reservoir surface during summer stratification were < 100 micrograms/L. The greatest concentration occurred during summer stagnation near the reservoir bottom at a deep site near Lake Conroe Dam. The concentrations of total inorganic nitrogen and total phosphorus were greatest during summer stratification in water near the reservoir bottom at deep sites. No accumulation of these constituents within the reservoir was detected during the study. The densities and composition of algal populations varied seasonally. Algal densities were greatest during the summer with blue-green algae being the predominant phylum. (Author 's abstract)

  8. A "Fossil Vadose Zone" from the Triassic Cooper Canyon Formation (Dockum Group) of West Texas

    NASA Astrophysics Data System (ADS)

    Holt, R. M.; Hughes, E.; Hubbell, J. M.; Grisak, G.; Cook, S.; Pickens, J.; Griffith, B. C.

    2008-12-01

    Hydrogeologic investigations at a proposed low-level radioactive waste disposal facility in Andrews County, Texas, have revealed evidence of a "fossil vadose zone" present within the redbeds of the Cooper Canyon Formation. The Cooper Canyon Formation is the uppermost stratigraphic unit in the Triassic Dockum Group in the study area and consists of very low permeability claystone and mudstone with several areally extensive siltstone/sandstone interbeds. Piezometers installed within two of the siltstone/sandstone zones show that water levels can rise up to about 20 m above the top of the zones and that uppermost of these zones is locally unsaturated. Waters in these zones have radiometric age dates of about 16,000 years. Recently twelve boreholes were drilled into the Cooper Canyon, cored, and sampled for in situ water potential (the sum of the matric and osmotic potential) and other hydraulic properties including moisture content, porosity, electrical conductivity of a saturated paste (EC), and chloride content. Water potential and saturation data show that Cooper Canyon mudstones are unsaturated to depths greater than 110 m with water potentials typically ranging from -2 MPa to -5 MPa. Very low water potentials (less than -1 MPa) occur within 0.1 m to 1 m of the upper and lower contacts of the siltstone/sandstone zones. Hydraulic gradients are outward from the siltstone/sandstone zones, and water potential values in the mudstones show one or more minima. These conditions preclude vertical flow between the land surface and underlying units and between siltstone/sandstone zones. The average air-entry pressure for Cooper Canyon rocks is about -1 MPa, and water saturation averages 83%. Chloride concentration profiles show a strong bulge in the sediments and rocks above the Cooper Canyon suggesting that very little Holocene recharge has reached the redbeds. Chloride concentrations within the siltstone/sandstone zones are higher than the surrounding mudstones, indicating

  9. Characterization of Hydraulically Significant Discontinuities in Mudrocks at the Waste Control Specialists (WCS) Site, West Texas

    NASA Astrophysics Data System (ADS)

    Kuszmaul, J. S.; Holt, R. M.; Powers, D. W.; Beauheim, R.; Pickens, J. F.; grisak, G. E.; Hughes, E.; Cook, S.

    2011-12-01

    Triassic mudrocks of the Dockum Group (Cooper Canyon Formation) host four, below-grade landfills at the Waste Control Specialists (WSC) site in Andrews County, Texas, including: a hazardous waste landfill and three radioactive waste landfills. At many radioactive waste disposal facilities, the long-term performance of the facility may be influenced by the transport of radionuclides through interconnected fracture networks. WCS developed an integrated geologic mapping and hydraulic testing program to evaluate the hydraulic significance of discontinuities within Dockum rocks. At the WCS site, the Dockum consists of mudrocks with sparse siltstone/sandstone interbeds that developed in a semi-arid environment from an ephemeral meandering fluvial system. Sedimentary studies reveal that the mudrocks are ancient floodplain vertisols (soils with swelling clays) and siltstone/sandstone interbeds are fluvial channel deposits that were frequently subaerially exposed. Rock discontinuities, including fractures, were mapped during the excavation of the WCS radioactive waste landfills along vertical faces prepared by the construction contractor. Face locations were selected to insure nearly complete vertical coverage for each landfill. Individual discontinuities were mapped and their strike, dip, length, roughness, curvature, staining, and evidence of displacement were described. In the three radioactive waste disposal landfills, over 1750 discontinuities across 35 excavated faces were mapped and described, where each face was nominally 8 to 10 ft tall and 50 to 100 ft long. On average, the orientation of the discontinuities was horizontal, and no other significant trends were observed. Mapping within the landfill excavations shows that most discontinuities within Dockum rocks are horizontal, concave upward, slickensided surfaces that developed in the depositional environment, as repeated wetting and drying cycles led to shrinking and swelling of floodplain vertisols. Fractures

  10. Site-investigation report. 147th Fighter Interceptor Group Texas Air National Guard, Ellington Field, Houston, Texas. Final report

    SciTech Connect

    Steakley, L.G.

    1991-01-04

    This document is a site investigation report on Ellington Field, Houston, Texas, as the second phase of the Installation Restoration Program. The report outlines the results from geophysical surveys, soil sampling, ground water samplings, surface soil samplings, and hydrology studies. Two sites were investigated in this study to confirm or deny the presence of contamination. At former landfills geophysical surveys were completed to locate any underground storage tanks that might be present. Two possible locations were noted from the surveys. The soils and ground water samples taken did not show any volatile organic compounds. Pesticides were reported in low concentrations in soils and ground water and several BNA's were present in surface soil samples. The preliminary risk assessment concluded that there did not appear to be any risk to human health or the environment and the site was recommended for no further action. At a Petroleum, Oil, and Lubricants Area (POL), contamination was detected in soil samples and in one monitoring well. The site was recommended for further study, so the extent of petroleum hydrocarbons contamination could be established and the soil remediated.

  11. Cretaceous basaltic phreatomagmatic volcanism in West Texas: Maar complex at Peña Mountain, Big Bend National Park

    NASA Astrophysics Data System (ADS)

    Befus, K. S.; Hanson, R. E.; Lehman, T. M.; Griffin, W. R.

    2008-06-01

    A structurally complex succession of basaltic pyroclastic deposits produced from overlapping phreatomagmatic volcanoes occurs within Upper Cretaceous floodplain deposits in the Aguja Formation in Big Bend National Park, West Texas. Together with similar basaltic deposits recently documented elsewhere in the Aguja Formation, these rocks provide evidence for an episode of phreatomagmatic volcanism that predates onset of arc magmatism in the region in the Paleogene. At Peña Mountain, the pyroclastic deposits are ≥ 70 m thick and consist dominantly of tabular beds of lapillistone and lapilli tuff containing angular to fluidal pyroclasts of altered sideromelane intermixed with abundant accidental terrigenous detritus derived from underlying Aguja sediments. Tephra characteristics indicate derivation from phreatomagmatic explosions involving fine-scale interaction between magma and sediment in the shallow subsurface. Deposition occurred by pyroclastic fall and base-surge processes in near-vent settings; most base-surge deposits lack tractional sedimentary structures and are inferred to have formed by suspension sedimentation from rapidly decelerating surges. Complexly deformed pyroclastic strata beneath a distinct truncation surface within the succession record construction and collapse of an initial volcano, followed by a shift in the location of the conduit and excavation of another maar crater into Aguja strata nearby. Preserved portions of the margin of this second crater are defined by a zone of intense soft-sediment disruption of pyroclastic and nonvolcanic strata. U-Pb isotopic analyses of zircon grains from three basaltic bombs in the succession reveal the presence of abundant xenocrysts, in some cases with ages > 1.0 Ga. The youngest concordant analyses for all three samples yield a weighted mean age of 76.9 ± 1.2 Ma, consistent with the presence of Late Campanian vertebrate fossils in the upper Aguja Formation. We infer that the volcanism is related to the

  12. Constraints on fluids and mass transfer during high-temperature during high-temperature contact metamorphism: Marble Canyon, west Texas

    SciTech Connect

    Anovitz, L.M.; Kalin, R.M.; Ruiz, J. . Dept. of Geosciences)

    1992-01-01

    Contact metamorphism of the Hueco and Bone Springs Limestones, Marble Canyon, west Texas formed sanidinite facies assemblages near the contact. Mw + Mel + Rn + Sp lies between: 2Mo + Rn = Ak + Mw and Mw + Rn = Ak + 2[alpha]C[sub 2]S, on Sp + Ak = 3Mw + Rn + CO[sub 2], and below Sp + Rn = [alpha]C[sub 2]S + CO[sub 2]. Assuming P = 370 bars and correcting for solid solutions yields contact temperatures of 700--800 C, and 0.001 < XCO[sub 2] < 0.02. Further from the contact carbonate-bearing assemblages reappear. Several distal samples contain Di + Dol. This assemblage lies below Di + 3Dol = 2Of + 4Cc + 2CO[sub 2], above Dol + 2Qz = Di + 2CO[sub 2], and at XCO[sub 2] concentrations above Tr + 3Cc = 4Di + Dol + CO[sub 2] + H[sub 2]O. These reactions imply 400 C < T < 500 C and XCO[sub 2] > 0.95. Thus there appear to have been large lateral gradients in XCO[sub 2] during metamorphism. Stable isotopic results verify the apparent differences between the two formations. Trace element data are currently only available from the Hueco Fm. REE patterns are light element enriched, and show intermediate to strong Eu and distinct Ce anomalies. La/Yb ratios fall into two groups 14--65 for some samples near the contact, and 8--16 for bulk rock samples at greater distances. U concentrations are high in the skarn, low in the marble near the contact and increase with distance. Ta, W, Pb, Cs and Ba concentrations also increase with distance, although the Ta, W, and Pb depletion is concentrated within 20 cm of the contact. Transects for all of these elements, however, contains significant internal structure.

  13. Rainfall and temperature distinguish between Karnal bunt positive and negative years in wheat fields in Texas.

    PubMed

    Workneh, F; Allen, T W; Nash, G H; Narasimhan, B; Srinivasan, R; Rush, C M

    2008-01-01

    Karnal bunt of wheat, caused by the fungus Tilletia indica, is an internationally regulated disease. Since its first detection in central Texas in 1997, regions in which the disease was detected have been under strict federal quarantine regulations resulting in significant economic losses. A study was conducted to determine the effect of weather factors on incidence of the disease since its first detection in Texas. Weather variables (temperature and rainfall amount and frequency) were collected and used as predictors in discriminant analysis for classifying bunt-positive and -negative fields using incidence data for 1997 and 2000 to 2003 in San Saba County. Rainfall amount and frequency were obtained from radar (Doppler radar) measurements. The three weather variables correctly classified 100% of the cases into bunt-positive or -negative fields during the specific period overlapping the stage of wheat susceptibility (boot to soft dough) in the region. A linear discriminant-function model then was developed for use in classification of new weather variables into the bunt occurrence groups (+ or -). The model was evaluated using weather data for 2004 to 2006 for San Saba area (central Texas), and data for 2001 and 2002 for Olney area (north-central Texas). The model correctly predicted bunt occurrence in all cases except for the year 2004. The model was also evaluated for site-specific prediction of the disease using radar rainfall data and in most cases provided similar results as the regional level evaluation. The humid thermal index (HTI) model (widely used for assessing risk of Karnal bunt) agreed with our model in all cases in the regional level evaluation, including the year 2004 for the San Saba area, except for the Olney area where it incorrectly predicted weather conditions in 2001 as unfavorable. The current model has a potential to be used in a spray advisory program in regulated wheat fields. PMID:18943243

  14. A review of noise data collection at the central and south west wind farm in Texas

    SciTech Connect

    Moroz, E.

    1996-12-31

    Evaluation of data collected over a 1-year period from a 6 MW wind farm is presented in the paper. Noise propagation prediction methods are compared with each other and with field data. Three forms of regulating noise are also compared: minimum separation distance, absolute noise limit, and relative noise limit.Relative noise limits were found to offer the most comprehensive approach to regulating noise and to allow each location to be treated independently. A hemispherical spreading model appears to be a useful planning tool. 11 refs., 4 tabs.

  15. Case history - installation of high volume pumping equipment in Talco Field, Texas

    SciTech Connect

    Rose, J.D.

    1982-01-01

    The work presents a case history study of Exxon's high volume artificial lift program at Talco Field in Franklin and Titus Counties, Texas. The field produces heavy crude oil from the Paluxy sandstone at an approximate depth of 4200 ft. Discussion includes (1) screening parameters used to optimized selection of high volume artificial lift equipment; (2) representative production flowstreams to quantify the additional recovery expected; (3) analysis of incremental expenses and costs associated with electric submersible pumps and large capacity beam pumping units; and (4) case production histories and operational problems encountered.

  16. Regional Variation in the Timing of Cessation of Laramide Folding, Uplift, and Post Flat-Slab Ignimbrite Flare Ups in West Texas

    NASA Astrophysics Data System (ADS)

    Davidson, M. E.; Casey, J.; Lapen, T. J.

    2013-12-01

    Tertiary volcanism in the Trans-Pecos region of West Texas is thought to be related to: 1) a major Farallon buoyant object-related slab flattening period resulting in early arc volcanic activity progressively shifting eastward to New Mexico and West Texas, 2) a subsequent slab-steepening/roll back or slab break away period resulting in renewed and extensive volcanism and ignimbrite flare ups across the region, and 3) final minor volcanism related to Basin and Range extension. Evidence for these tectonic induced volcanic periods can be observed in volcanic compositional variation and the timing and style of volcanism and deformation. This includes highly varied pre-folding mafic alkaline and calc-alkane volcanic and intrusive rocks from ~46Ma (Eocene) to ~32Ma (Oligocene). This is followed by broadly distributed, post-folding calc-alkaline volcanism with subsidiary alkaline mafic volcanism during subsequent regionally varying slab steepening or break away periods (38Ma to 28Ma). Later, smaller-scale, almost exclusively mafic volcanism is associated with Basin and Range extension that occurred between 25 to 2Ma (Barker, 1987). This study attempts to refine regional differences in the cessation of Laramide folding and episodic slab-asthenosphere influenced volcanism in West Texas by utilizing LA-ICP-MS U/Pb zircon geochronology. Ages have been measured for volcanic rock samples that occur both above and below the angular unconformity, including: the Eagle Mountain Lower Rhyolite, an unnamed tuff and trachyte unit from the Garren Group in the Indio Mountains, the Davis Mountains Huelster Fm. and Petan Basalts, the Chinati Mountains Morita Ranch Fm., the Tascotal Fm. From the Alamito Creek and Green Valley area, the Vieja Group from the Rio Grande River area, and the Big Bend National Park South Rim Fm. and Chisos Fm.. In addition, ages for detrital zircons have been obtained in silicilastics below the unconformity within Tertiary Black Peaks, Hannold Hill, and Canoe

  17. Characterization of diagenetically altered carbonate reservoirs, South Cowden Grayburg Reservoir, West Texas

    SciTech Connect

    Lucia, F.J.; Ruppel, S.C.

    1996-12-31

    Much of the difficulty in constructing carbonate reservoir models for fluid-flow simulation results from diagenetic overprinting of depositional permeability patterns. In the South Cowden field, diagenetic effects result in (1) low porosity and permeability in the western and northern areas due to reduction of porosity by means of dolomitization and post-dolomitization compaction, (2) elimination of the petrophysical effects of depositional texture resulting from changes in particle size due to dolomitization, and (3) creation of a touching-vug pore system due to anhydrite dissolution. The extent of anhydrite alteration can be mapped to show three distinct diagenetic areas: those dominated by unaltered, altered, or dissolved anhydrite. Each alteration type has a unique acoustic-porosity transform that can be used to map the diagenetic areas and to calculate porosity when only acoustic logs are available. A single porosity-permeability transform characterizes the areas having unaltered and altered anhydrite, and the depositional stratigraphy is useful in constructing a reservoir model. A more favorable transform characterizes the area of dissolved anhydrite, and depositional stratigraphy is not useful in constructing a reservoir model because of the large effect of the diagenetic overprint.

  18. A theoretical model of subsidence caused by petroleum production: Big Hill Field, Jefferson County, Texas

    SciTech Connect

    Hill, D.W.; Sharp, J.M. Jr. . Dept. of Geological Sciences)

    1993-02-01

    In the Texas Gulf Coastal Plain, there is a history of oil and gas production extending over 2 to 5 decades. Concurrent with this production history, there has been unprecedented population growth accompanied by vastly increased groundwater demands. Land subsidence on both local and regional bases in this geologic province has been measured and predicted in several studies. The vast majority of these studies have addressed the problem from the standpoint of groundwater usage while only a few have considered the effects of oil and gas production. Based upon field-based computational techniques (Helm, 1984), a model has been developed to predict land subsidence caused by oil and gas production. This method is applied to the Big Hill Field in Jefferson County, Texas. Inputs include production data from a series of wells in this field and lithologic data from electric logs of these same wells. Outputs include predicted amounts of subsidence, the time frame of subsidence, and sensitivity analyses of compressibility and hydraulic conductivity estimates. Depending upon estimated compressibility, subsidence, to date, is predicted to be as high as 20 cm. Similarly, depending upon estimated vertical hydraulic conductivity, the time frame may be decades for this subsidence. These same methods can be applied to other oil/gas fields with established production histories as well as new fields when production scenarios are assumed. Where subsidence has been carefully measured above petroleum reservoir, the model may be used inversely to calculate sediment compressibilities.

  19. Evaluation of area of review variance opportunities for the East Texas field. Annual report

    SciTech Connect

    Warner, D.L.; Koederitz, L.F.; Laudon, R.C.; Dunn-Norman, S.

    1995-05-01

    The East Texas oil field, discovered in 1930 and located principally in Gregg and Rusk Counties, is the largest oil field in the conterminous United States. Nearly 33,000 wells are known to have been drilled in the field. The field has been undergoing water injection for pressure maintenance since 1938. As of today, 104 Class II salt-water disposal wells, operated by the East Texas Salt Water Disposal Company, are returning all produced water to the Woodbine producing reservoir. About 69 of the presently existing wells have not been subjected to U.S. Environmental Protection Agency Area-of-Review (AOR) requirements. A study has been carried out of opportunities for variance from AORs for these existing wells and for new wells that will be constructed in the future. The study has been based upon a variance methodology developed at the University of Missouri-Rolla under sponsorship of the American Petroleum Institute and in coordination with the Ground Water Protection Council. The principal technical objective of the study was to determine if reservoir pressure in the Woodbine producing reservoir is sufficiently low so that flow of salt-water from the Woodbine into the Carrizo-Wilcox ground water aquifer is precluded. The study has shown that the Woodbine reservoir is currently underpressured relative to the Carrizo-Wilcox and will remain so over the next 20 years. This information provides a logical basis for a variance for the field from performing AORs.

  20. Studying Geology of Central Texas through Web-Based Virtual Field Trips

    NASA Astrophysics Data System (ADS)

    Chan, C.; Khan, S. D.; Wellner, J. S.

    2007-12-01

    Each year over 2500 students, mainly non-science majors, take introductory geology classes at the University of Houston. Optional field trips to Central Texas for these classes provide a unique learning opportunity for students to experience geologic concepts in a real world context. The field trips visit Enchanted Rock, Inks Lake, Bee Cave Road, Lion Mountain, and Slaughter Gap. Unfortunately, only around 10% of our students participate in these field trips. We are developing a web-based virtual field trip for Central Texas to provide an additional effective learning experience for students in these classes. The module for Enchanted Rock is complete and consists of linked geological maps, satellite imagery, digital elevation models, 3-D photography, digital video, and 3-D virtual reality visualizations. The ten virtual stops focus on different geologic process and are accompanied by questions and answers. To test the efficacy of the virtual field trip, we developed a quiz to measure student learning and a survey to evaluate the website. The quiz consists of 10 questions paralleling each stop and information on student attendance on the Central Texas field trip and/or the virtual field trip. From the survey, the average time spent on the website was 26 minutes, and overall the ratings of the virtual field trip were positive. Most noticeably students responded that the information on the website was relevant to their class and that the pictures, figures, and animations were essential to the website. Although high correlation coefficients between responses were expected for some questions (i.e., 0.89 for "The content or text of the website was clear" and "The information on the website was easy to read"), some correlations were less expected: 0.77 for "The number of test questions was appropriate" and "The information on the website was easy to read," and 0.70 for "The test questions reinforced the material presented on the website" and "The information on the

  1. Application of integrated remote sensing and GIS technologies to geological, agricultural, water and environmental issues in far west Texas

    NASA Astrophysics Data System (ADS)

    Xie, Hongjie

    This study focuses on applying integrated remote sensing and GIS technologies to geological, agricultural, water and environmental studies in the far west Texas area. The primary technical topics that have been investigated and employed include radar image processing, speckle removal, destriping, data fusion, seamless image mosaicking technology, mask and ROI techniques, DEM processing and 3D visualization, image classification techniques, gravity and magnetic data processing, algorithm implementation for automatic image registration, ArcView/ArcInfo GIS techniques, and GIS database building. JPL/NASA's AIRSAR/TOPSAR is a multipolarimetric, multiwavelength, and interferometric airborne synthetic aperture radar capable of imaging in C-, L-, and P-bands (5.7, 24.5, and 68 cm). The study mainly focuses on its preprocessing, despeckling, and destriping. Among statistical adaptive speckle removal algorithms, G-MAP (Gamma Maximum A Posteriori) had the best performance. For banding removal, we derived a new method that we call combined principal components analysis (CPCA) that was very effective with our data. Signature differences were studied and compared at different radar wavelengths and between radar and optical (ETM+) images. Some subsurface objects (like water pipelines) were clearly visible in the radar images, especially for the P-band. Data fusion based on the color transform technique was employed to integrate Landsat 7 (30 m ETM+ data fused with the accompanying 15 m panchromatic data) and TOPSAR data after speckle and banding removal. The resulting fused image brought out new features that were not evident in the original images and helped identify many features whose origin was not clear in the original images. AIRSAR/TOPSAR and TM/ETM+ images have been successfully used for mapping the East Franklin Mountains fault scarp and related small faults within the Hueco bolson as well as the Mayfield fault scarp. Remote sensing analysis of nuclear waste disposal

  2. Field trip guidebook on environmental impact of clays along the upper Texas coast

    NASA Technical Reports Server (NTRS)

    Garcia, Theron D.; Ming, Douglas W.; Tuck, Lisa Kay

    1991-01-01

    The field trip was prepared to provide an opportunity to see first hand some the environmental hazards associated with clays in the Houston, Texas area. Because of the very high clay content in area soils and underlying Beaumont Formation clay, Houston is a fitting location to host the Clay Mineral Society. Examinations were made of (1) expansive soils, (2) subsidence and surface faulting, and (3) a landfill located southeast of Houston at the Gulf Coast Waste Disposal Authority where clay is part of the liner material.

  3. Hands-on Marine Geology and Geophysics Field Instruction at the University of Texas

    NASA Astrophysics Data System (ADS)

    Saustrup, S.; Gulick, S. P. S.; Goff, J. A.; Fernandez, R.; Davis, M. B.; Duncan, D.

    2015-12-01

    The University of Texas Institute for Geophysics, part of the Jackson School of Geosciences, annually offers an intensive three-week marine geology and geophysics field course during the spring-summer intersession. Now in its ninth year, the course provides instruction in survey design, data acquisition, processing, interpretation, and visualization. Methods covered include seismic reflection, multibeam bathymetry, sidescan sonar, and sediment sampling. The emphasis of the course is team-oriented, hands-on, field training in real-world situations. The course begins with classroom instruction covering the field area and field methods, followed by a week of at-sea field work in 4-student teams. The students then return to the classroom where they integrate, interpret, and visualize data using industry-standard software. The teams present results in a series of professional-level final presentations before academic and industry supporters. Our rotating field areas provide ideal locations for students to investigate coastal and sedimentary processes of the Gulf Coast and continental shelf . In the field, student teams rotate between two research vessels: the smaller vessel, the Jackson School's newly-commissioned R/V Scott Petty (26 feet LOA), is used principally for multibeam bathymetry, sidescan sonar, and sediment sampling; the other, NOAA's R/V Manta (82 feet LOA) is used for high-resolution seismic reflection, CHIRP sub-bottom profiling, multibeam bathymetry, gravity coring, and vibracoring. Teams also rotate through a field laboratory performing processing of geophysical data and sediment samples. This past year's course in Freeport, Texas proceeded unabated despite concurrent record-breaking rainfall and flooding, which offered students a unique opportunity to observe and image, in real time, flood-related bedform migration on a time scale of hours. The data also allowed an in-class opportunity to examine natural and anthropogenic processes recorded in the river

  4. Bird use of agricultural fields under reduced and conventional tillage in the Texas Panhandle

    USGS Publications Warehouse

    Flickinger, Edward L.; Pendleton, G.W.

    1994-01-01

    We conducted bird surveys in reduced-tillage and conventional tillage fields in spring, summer, fall, and winter from 1987 to 1991 in the Texas Panhandle. Eastern meadowlarks, longspurs, and savannah sparrows were more common in reduced-tillage (sorghum and wheat stubble) fields than in conventionally tilled (plowed) fields in at least 1 season. Other species also had patterns suggestive of greater abundance in reduced-tillage fields. Hornedlarks, which prefer habitat with sparse vegetation, were more abundant in plowed fields in all seasons except summer. Bird diversity was greater in reduced-tillage fields than in conventionally tilled fields in summer. Cover density and height were greater in reduced tillage fields in all seasons except spring. Cover density and height rather than cover composition (e.g.,grain stubble or live plants) seemed to be the important factors affecting bird distribution. Patterns of bird abundance between sorghum and wheat stubble fields also were dependent on cover. Herbicide use was not greater in reduced-tillage fields than in conventionally tilled fields. Reduced-tillage agriculture for sorghum and wheat farming should be encouraged in the southern Great Plains as a means of improving the attractiveness of agricultural land to many bird species.

  5. Quantitative geophysical investigations at the Diamond M field, Scurry County, Texas

    NASA Astrophysics Data System (ADS)

    Davogustto Cataldo, Oswaldo Ernesto

    The Diamond M field over the Horseshoe Atoll reservoir of west Texas has produced oil since 1942. Even with some 210 well penetrations, complex reservoir compartmentalization has justified an ongoing drilling program with three wells drilled within the last three years. Accurate reservoir characterization requires accurate description of the geometry, geological facies, and petrophysical property distribution ranging from core, through log to the seismic scale. The operator has conducted a careful logging and coring process including dipole sonic logs in addition to acquiring a modern 3D vertical phone - vertical vibrator "P-wave" seismic data volume and an equivalent size 2-component by 2-componet "S-wave" seismic data volume. I analyze these data at different scales, integrating them into a whole. I begin with core analysis of the petrophysical properties of the Horseshoe Atoll reservoir. Measuring porosity, permeability, NMR T2 relaxation and velocities (Vp and Vs) as a function of pressure and find that porosity measurements are consistent when measured with different techniques. When upscaled, these measurements are in excellent agreement with properties measured at the log scale. Together, these measurements provide a lithology-porosity template against which I correlate my seismic P- and S-impedance measurements. Careful examination of P- and S-impedances as well as density from prestack inversion of the P-wave survey of the original time migrated gathers showed lower vertical resolution for S-impedance and density. These latter two parameters are controlled by the far-offset data, which suffers from migration stretch. I address this shortcoming by applying a recently developed non-stretch NMO technique which not only improved the bandwidth of the data but also resulted in inversions that better match the S-impedance and density well log data. The operator hypothesized that 2C by 2C S-wave data would better delineate lithology than conventional P

  6. Application of advanced reservoir characterization, simulation, and production optimization strategies to maximize recovery in slope and basin clastic reservoirs, West Texas (Delaware Basin). Quarterly report, October 1 - December 31, 1996

    SciTech Connect

    Dutton, S.P.

    1997-01-01

    The objective of this project is to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost effective way to recover a higher percentage of the original oil in place through strategic placement of infill wells and geologically based field development. Project objectives are divided into two major phases. The objectives of the reservoir characterization phase of the project are to provide a detailed understanding of the architecture and heterogeneity of two fields, the Ford Geraldine unit and Ford West field, which produce from the Bell Canyon and Cherry Canyon Formations, respectively, of the Delaware Mountain Group and to compare Bell Canyon and Cherry Canyon reservoirs. Reservoir characterization will utilize 3-D seismic data, high-resolution sequence stratigraphy, subsurface field studies, outcrop characterization, and other techniques. Once the reservoir-characterization study of both fields is completed, a pilot area of approximately 1 mi{sup 2} in one of the fields will be chosen for reservoir simulation. The objectives of the implementation phase of the project are to (1) apply the knowledge gained from reservoir characterization and simulation studies to increase recovery from the pilot area, (2) demonstrate that economically significant unrecovered oil remains in geologically resolvable untapped compartments, and (3) test the accuracy of reservoir characterization and flow simulation as predictive tools in resource preservation of mature fields. A geologically designed, enhanced-recovery program (CO{sub 2} flood, waterflood, or polymer flood) and well-completion program will be developed, and one to three infill wells will be drilled and cored. Technical progress is summarized for: geophysical characterization; reservoir characterization; outcrop characterization; and recovery technology identification and analysis.

  7. Application of advanced reservoir characterization, simulation, and production optimization strategies to maximize recovery in slope and basin clastic reservoirs, West Texas (Delaware Basin). Quarterly report, July 1 - September 30, 1996

    SciTech Connect

    Dutton, S.P.

    1996-10-01

    The objective of this project is to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost effective way to recover a higher percentage of the original oil in place through strategic placement of infill wells and geologically based field development. Project objectives are divided into two major phases. The objectives of the reservoir characterization phase of the project are to provide a detailed understanding of the architecture and heterogeneity of two fields, the Ford Geraldine unit and Ford West field, which produce from the Bell Canyon and Cherry Canyon Formations, respectively, of the Delaware Mountain Group and to compare Bell Canyon and Cherry Canyon reservoirs. Reservoir characterization will utilize 3-D seismic data, high-resolution sequence stratigraphy, subsurface field studies, outcrop characterization, and other techniques. Once the reservoir- characterization study of both fields is completed, a pilot area of approximately 1 mi{sup 2} in one of the fields will be chosen for reservoir simulation. The objectives of the implementation phase of the project are to (1) apply the knowledge gained from reservoir characterization and simulation studies to increase recovery from the pilot area, (2) demonstrate that economically significant unrecovered oil remains in geologically resolvable untapped compartments, and (3) test the accuracy of reservoir characterization and flow simulation as predictive tools in resource preservation of mature fields. A geologically designed, enhanced-recovery program (CO{sup 2} flood, waterflood, or polymer flood) and well-completion program will be developed, and one to three infill wells will be drilled and cored. Accomplishments for this past quarter are discussed.

  8. Application of advanced reservoir characterization, simulation, and production optimization strategies to maximize recovery in slope and basin clastic reservoirs, West Texas (Delaware Basin). Quarterly report, April 1,1996 - June 30, 1996

    SciTech Connect

    Dutton, S.P.

    1996-07-01

    The objective of this project is to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost effective way to recover a higher percentage of the original oil in place through strategic placement of infill wells and geologically based field development. Project objectives are divided into two major phases. The objectives of the reservoir characterization phase of the project are to provide a detailed understanding of the architecture and heterogeneity of two fields, the Ford Geraldine unit and Ford West field, which produce from the Bell Canyon and Cherry Canyon Formations, respectively, of the Delaware Mountain Group and to compare Bell Canyon and Cherry Canyon reservoirs. Reservoir characterization will utilize 3-D seismic data, high-resolution sequence stratigraphy, subsurface field studies, outcrop characterization, and other techniques. Once the reservoir- characterization study of both fields is completed, a pilot area of approximately 1 mi{sup 2} in one of the fields will be chosen for reservoir simulation. The objectives of the implementation phase of the project are to (1) apply the knowledge gained from reservoir characterization and simulation studies to increase recovery from the pilot area, (2) demonstrate that economically significant unrecovered oil remains in geologically resolvable untapped compartments, and (3) test the accuracy of reservoir characterization and flow simulation as predictive tools in resource preservation of mature fields. A geologically designed, enhanced-recovery program (CO{sub 2} flood, waterflood, or polymer flood) and well-completion program will be developed, and one to three infill wells will be drilled and cored. Progress to date is summarized for reservoir characterization.

  9. Combined geological and surface geochemical methods discover Agaritta and Brady Creek fields, Concho County, Texas

    SciTech Connect

    Saunders, D.F.; Burson, K.R.; Thompson, C.K. ); Brown, J.J. )

    1992-04-01

    From December 1987 to March 1991, 25 prospects in the lower King Sandstone (Upper Pennsylvanian Cisco) play in Concho County, Texas, were tested by several operators. They used combinations of subsurface geology, reconnaissance airborne gas sensing, surface radiometrics, soil magnetic susceptibility, and soil gas hydrocarbon measurements to define prospects. Six new King Sandstone field discoveries or extensions and three deeper pay Goen Limestone field discoveries resulted in a 36% exploratory success rate. The total exploration and development cost was approximately $0.67 per bbl of proven producing oil reserves. As examples, the authors present the discovery of Brady Creek and Agaritta fields. Agaritta field is one of the two largest of the new field discoveries with estimated proven producing recoverable reserves of 6,000,000 BO. Its discovery was based on a combination of (1) airborne hydrocarbon sensing, (2) interstitial soil gas hydrocarbon data, (3) soil magnetic susceptibility measurements, and (4) surface potassium and uranium concentrations measured by gamma-ray spectrometry. Interstitial soil gas hydrocarbon anomalies combined with soil magnetic susceptibility anomalies provided the best detailed surface guidance to Agaritta field. These were supported locally by radiometric anomalies. The Brady Creek field is interpreted to be a possible crevasse splay deposit. The Aggaritta field is interpreted to be a point bar deposit. Both fields are stratigraphic traps.

  10. New Ulm field: an example of Cretaceous shelf-slope instability in east Texas

    SciTech Connect

    Pinero, E.

    1984-04-01

    The New Ulm field in Austin County, Texas, is an example of the structural and stratigraphic complexity above the Cretaceous Edwards shelf margin of east Texas. Deep wells and improved seismic data provide documentation of structural patterns and deepwater facies not previously considered in the Gulf Coast reservoir play modeling. Study of the data implies the Late Cretaceous to Eocene section was deposited along a shelf-slope break. Late Cretaceous, pre-Midway sedimentation was affected by structurally induced slope instability, and consequent gravity faulting and slumping resulted in an irregular sea-floor surface. Paleocene Midway sands were carried onto this surface by storm-generated density currents where the uneven topography caused deposition in constructional channels. Continued deposition of the fluvio-deltaic Wilcox on this surface caused faulting and folding by differential compaction. The folds are minor and the faults small and steep, not like the typical large growth faults of the Gulf Coast. Upper Wilcox sediments were progressively less disturbed as the region stabilized. New Ulm field production includes gas from the Midway Formation and oil and gas from the Wilcox Group. Midway reservoirs are stratigraphic, consisting of fluvio-deltaic sandstones within faulted anticlines. This study adds evidence to data describing shelf-slope geology along the Edwards margin. The setting can be a new type of hydrocarbon play in the Gulf Coast.

  11. Spatial variability in methane emissions from a Texas rice field with some general implications

    NASA Astrophysics Data System (ADS)

    Sass, Ronald L.; Fisher, Frank M.; Andrews, Jeffrey A.

    2002-03-01

    This study addresses the issue of the effect of spatial variability within a single rice field on methane emissions observed using static flux boxes. The experimental data were collected from a commercially farmed field located near Richmond, Texas. The field was managed according to the normal practice of the area, including continuous flooding and the use of only inorganic fertilizer. Twenty-four experimental plots were employed to measure daily and seasonal methane emission, seasonal aboveground biomass, and soil texture. A statistical analysis of the data provided predictive information on the precision with which static flux box measurements can determine the actual methane emission value in a particular field. The results of this study are related to the general global question of spatial variability in rice fields by comparisons with experimental and calculated methane emissions from several comparably managed rice fields around the world. Results from the present study indicate that methane emission values obtained from static flux box measurements are within +/-20% of the actual field values within a 95% confidence interval. A comparison of this study with other reported results and related model calculations indicate that static flux box measurements are within +/-24% of the actual field values.

  12. Subsurface evaluation of the west parking lot and landfill 3 areas of Air Force Plant 4, Fort Worth, Texas, using two-dimensional direct-current resistivity profiling

    USGS Publications Warehouse

    Braun, Christopher L.; Jones, Sonya A.

    2002-01-01

    During September 1999, the U.S. Geological Survey made 10 two-dimensional direct-current resistivity profile surveys in the west parking lot and landfill 3 areas of Air Force Plant 4, Fort Worth, Texas, to identify subsurface areas of anomalously high or low resistivity that could indicate potential contamination, contaminant pathways, or anthropogenic structures. Six of the 10 surveys (transects) were in the west parking lot. Each of the inverted sections of these transects had anomalously high resistivities in the terrace alluvium/fill (the surficial subsurface layer) that probably were caused by highly resistive fill material. In addition, each of these transects had anomalously low resistivities in the Walnut Formation (a bedrock layer immediately beneath the alluvium/fill) that could have been caused by saturation of fractures within the Walnut Formation. A high-resistivity anomaly in the central part of the study area probably is associated with pea gravel fill used in construction of a French drain. Another high resistivity anomaly in the west parking lot, slightly southeast of the French drain, could be caused by dense nonaqueous-phase liquid in the Walnut Formation. The inverted sections of the four transects in the landfill 3 area tended to have slightly higher resistivities in both the alluvium/fill and the Walnut Formation than the transects in the west parking lot. The higher resistivities in the alluvium/fill could have been caused by drier conditions in grassy areas relative to conditions in the west parking lot. Higher resistivities in parts of the Walnut Formation also could be a function of drier conditions or variations in the lithology of the Walnut Formation. In addition to the 10 vertical sections, four horizontal sections at 2-meteraltitude intervals show generally increasing resistivity with decreasing altitude that most likely results from the increased influence of the Walnut Formation, which has a higher resistivity than the terrace

  13. Genetic Variability and Geographical Distribution of Mycotoxigenic Fusarium verticillioides Strains Isolated from Maize Fields in Texas

    PubMed Central

    Ortiz, Carlos S.; Richards, Casey; Terry, Ashlee; Parra, Joselyn; Shim, Won-Bo

    2015-01-01

    Maize is the dominant cereal crop produced in the US. One of the main fungal pathogens of maize is Fusarium verticillioides, the causative agent of ear and stalk rots. Significantly, the fungus produces a group of mycotoxins - fumonisins - on infested kernels, which have been linked to various illnesses in humans and animals. Nonetheless, durable resistance against F. verticillioides in maize is not currently available. In Texas, over 2.1 million acres of maize are vulnerable to fumonisin contamination, but understanding of the distribution of toxigenic F. verticillioides in maize-producing areas is currently lacking. Our goal was to investigate the genetic variability of F. verticillioides in Texas with an emphasis on fumonisin trait and geographical distribution. A total of 164 F. verticillioides cultures were isolated from 65 maize-producing counties. DNA from each isolate was extracted and analyzed by PCR for the presence of FUM1- a key fumonisin biosynthesis gene - and mating type genes. Results showed that all isolates are in fact F. verticillioides capable of producing fumonisins with a 1:1 mating-type gene ratio in the population. To further study the genetic diversity of the population, isolates were analyzed using RAPD fingerprinting. Polymorphic markers were identified and the analysis showed no clear correlation between the RAPD profile of the isolates and their corresponding geographical origin. Our data suggest the toxigenic F. verticillioides population in Texas is widely distributed wherever maize is grown. We also hypothesize that the population is fluid, with active movement and genetic recombination occurring in the field. PMID:26361468

  14. Genetic Variability and Geographical Distribution of Mycotoxigenic Fusarium verticillioides Strains Isolated from Maize Fields in Texas.

    PubMed

    Ortiz, Carlos S; Richards, Casey; Terry, Ashlee; Parra, Joselyn; Shim, Won-Bo

    2015-09-01

    Maize is the dominant cereal crop produced in the US. One of the main fungal pathogens of maize is Fusarium verticillioides, the causative agent of ear and stalk rots. Significantly, the fungus produces a group of mycotoxins - fumonisins - on infested kernels, which have been linked to various illnesses in humans and animals. Nonetheless, durable resistance against F. verticillioides in maize is not currently available. In Texas, over 2.1 million acres of maize are vulnerable to fumonisin contamination, but understanding of the distribution of toxigenic F. verticillioides in maize-producing areas is currently lacking. Our goal was to investigate the genetic variability of F. verticillioides in Texas with an emphasis on fumonisin trait and geographical distribution. A total of 164 F. verticillioides cultures were isolated from 65 maize-producing counties. DNA from each isolate was extracted and analyzed by PCR for the presence of FUM1- a key fumonisin biosynthesis gene - and mating type genes. Results showed that all isolates are in fact F. verticillioides capable of producing fumonisins with a 1:1 mating-type gene ratio in the population. To further study the genetic diversity of the population, isolates were analyzed using RAPD fingerprinting. Polymorphic markers were identified and the analysis showed no clear correlation between the RAPD profile of the isolates and their corresponding geographical origin. Our data suggest the toxigenic F. verticillioides population in Texas is widely distributed wherever maize is grown. We also hypothesize that the population is fluid, with active movement and genetic recombination occurring in the field. PMID:26361468

  15. INTEGRATED OUTCROP AND SUBSURFACE STUDIES OF THE INTERWELL ENVIRONMENT OF CARBONATE RESERVOIRS: CLEAR FORK (LEONARDIAN-AGE) RESERVOIRS, WEST TEXAS AND NEW MEXICO

    SciTech Connect

    F. Jerry Lucia

    2002-01-31

    This is the final report of the project ''Integrated Outcrop and Subsurface Studies of the Interwell Environment of Carbonate Reservoirs: Clear Fork (Leonardian-Age) Reservoirs, West Texas and New Mexico'', Department of Energy contract no. DE-AC26-98BC15105 and is the third in a series of similar projects funded jointly by the U.S. Department of Energy and The University of Texas at Austin, Bureau of Economic Geology, Reservoir Characterization Research Laboratory for Carbonates. All three projects focus on the integration of outcrop and subsurface data for the purpose of developing improved methods for modeling petrophysical properties in the interwell environment. The first project, funded by contract no. DE-AC22-89BC14470, was a study of San Andres outcrops in the Algerita Escarpment, Guadalupe Mountains, Texas and New Mexico, and the Seminole San Andres reservoir, Permian Basin. This study established the basic concepts for constructing a reservoir model using sequence-stratigraphic principles and rock-fabric, petrophysical relationships. The second project, funded by contract no. DE-AC22-93BC14895, was a study of Grayburg outcrops in the Brokeoff Mountains, New Mexico, and the South Cowden Grayburg reservoir, Permian Basin. This study developed a sequence-stratigraphic succession for the Grayburg and improved methods for locating remaining hydrocarbons in carbonate ramp reservoirs. The current study is of the Clear Fork Group in Apache Canyon, Sierra Diablo Mountains, West Texas, and the South Wasson Clear Fork reservoir, Permian Basin. The focus was on scales of heterogeneity, imaging high- and low-permeability layers, and the impact of fractures on reservoir performance. In this study (1) the Clear Fork cycle stratigraphy is defined, (2) important scales of petrophysical variability are confirmed, (3) a unique rock-fabric, petrophysical relationship is defined, (4) a porosity method for correlating high-frequency cycles and defining rock-fabric flow layers

  16. Single-well evaluation program for micellar/polymer recovery, Main and 99 West Pools, West Coyote field, California

    SciTech Connect

    Holland, K.M.; Porter, L.T.

    1983-01-01

    The Main and 99 West pools of the West Coyote field were selected as promising candidates for a micellar-polymer recovery project. Waterfloods initiated in 1961 are nearing their economic limit, with a current watered-oil ratio of 45. Well No. MC 374 was drilled in a water-out portion of the Main and 99 West reservoirs to accomplish an evaluation program with the following objectives: (1) provide data for an improved geologic model; (2) estimate current oil in place; and (3) determine the effectiveness of micellar-polymer chemicals in displacing residual oil. Well No. MC 374 was extensively cored and logged to provide the necessary geologic and reservoir data. A multi-well interference test was conducted to confirm reservoir continuity near the test well. Displacement tests were run in 2 intervals with micellar-polymer chemicals. 13 references.

  17. Reservoir zonation in Silurian-Devonian carbonates of Wells field, Dawson County, Texas

    SciTech Connect

    Mazzullo, L.J. )

    1992-04-01

    Wells field in Dawson County, Texas, has produced over 7.5 million bbl since 1955 from Silurian-Devonian carbonates. Although originally classified as a Devonian field, production there actually is out of the Silurian Wristen and Fusselman formations. Wells field is an extremely complex system of structured and stratigraphic reservoirs not easily characterized by traditional subsurface mapping techniques. Detailed lithologic analyses of well cuttings from 29 wells in and around this field were done to evaluate reservoir zonation and potentials for either new field development wells, or recompletions from existing well bores. These analyses have shown that paleotopographic highs on the Fusselman unconformity across the field created optimum sites for Fusselman dolomite reservoir development, and collateral development of Wristen reservoirs. The Wristen reservoirs are in the form of porous carbonate mounds that grew adjacent to the paleotopographically high areas, or simple compactionally fractured cherty carbonates over these highs. The recognition of Fusselman paleotopography in most wells is implied by thickness and facies changes in the overlying Wristen section. A certain amount of structure and facies-induced reservoir separation has been documented. The results of this study have been used to identify several areas of the field where each of the three reservoirs could be exploited for underdeveloped reserves.

  18. Soccer field at West 101st102nd streets, Riverside Park, looking south ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Soccer field at West 101st-102nd streets, Riverside Park, looking south with railroad retaining wall in background. - Henry Hudson Parkway, Extending 11.2 miles from West 72nd Street to Bronx-Westchester border, New York County, NY

  19. Marine Geology and Geophysics Field Course Offered by The University of Texas Institute for Geophysics

    NASA Astrophysics Data System (ADS)

    Duncan, D.; Davis, M. B.; Allison, M. A.; Gulick, S. P.; Goff, J. A.; Saustrup, S.

    2012-12-01

    The University of Texas Institute for Geophysics, part of the Jackson School of Geosciences, annually offers an intensive three-week marine geology and geophysics field course during the spring-summer intersession. Now in year six, the course provides hands-on instruction and training for graduate and upper-level undergraduate students in data acquisition, processing, interpretation, and visualization. Techniques covered include high-resolution seismic reflection, CHIRP sub-bottom profiling, multibeam bathymetry, sidescan sonar, several types of sediment coring, grab sampling, and the sedimentology of resulting seabed samples (e.g., core description, grain size analysis, x-radiography, etc.). Students participate in an initial period of classroom instruction designed to communicate geological context of the field area (which changes each year) along with theoretical and technical background on each field method. The class then travels to the Gulf Coast for a week of at-sea field work. Our field sites at Port Aransas and Galveston, Texas, and Grand Isle, Louisiana, have provided ideal locations for students to investigate coastal and sedimentary processes of the Gulf Coast and continental shelf through application of geophysical techniques. In the field, students rotate between two research vessels: one vessel, the 22' aluminum-hulled R/V Lake Itasca, owned and operated by UTIG, is used principally for multibeam bathymetry, sidescan sonar, and sediment sampling; the other, NOAA's R/V Manta or the R/V Acadiana, operated by the Louisiana Universities Marine Consortium, and is used primarily for high-resolution seismic reflection, CHIRP sub-bottom profiling, multibeam bathymetry, gravity coring, and vibrocoring. While at sea, students assist with survey design, learn instrumentation set up, acquisition parameters, data quality control, and safe instrument deployment and retrieval. In teams of three, students work in onshore field labs preparing sediment samples for

  20. Geophysical and geochronological constraints on the extent and age of mafic intrusions in the basement of west Texas and eastern New Mexico

    NASA Astrophysics Data System (ADS)

    Keller, G. Randy; Hills, John M.; Baker, Mark R.; Wallin, E. Timothy

    1989-11-01

    A deep drill hole recently completed on the Central basin platform of west Texas provides a rare look at almost 5 km of basement rocks. Most of the crystalline rocks encountered were basic and ultrabasic in composition. A variety of geophysical data is available from the bore hole and vicinity. The petrographic and geophysical data suggest that a large, layered, basic intrusion was penetrated by the well. Geochronologic (U-Pb) data indicate an age of about 1.1 Ga for this intrusion. This date has significant tectonic implications because it indicates that commonly accepted analogies with the southern Oklahoma aulacogen (550 Ma rifting) are not valid. However, it is interesting to note that this feature formed during another widespread period of rifting (Keweenawan).

  1. Calculation and interpretation of crustal shortening along the Central Basin Platform, West Texas: A method to calculate basement motion for modeling input

    SciTech Connect

    Hoak, T.E. |; Sundberg, K.R.; Ortoleva, P.

    1998-12-31

    The analysis carried out in the Chemical Interaction of Rocks and Fluids Basin (CIRFB) model describes the chemical and physical evolution of the entire system. One aspect of this is the deformation of the rocks, and its treatment with a rigorous flow and rheological model. This type of analysis depends on knowing the state of the model domain`s boundaries as functions of time. In the Andrews and Ector County areas of the Central Basin Platform of West Texas, the authors calculate this shortening with a simple interpretation of the basic motion and a restoration of the Ellenburger formation. Despite its simplicity, this calculation reveals two distinct periods of shortening/extension, a relatively uniform directionality to all the deformation, and the localization of deformation effects to the immediate vicinities of the major faults in the area. Conclusions are drawn regarding the appropriate expressions of these boundary conditions in the CIRFB model and possible implications for exploration.

  2. Evaluation of soil sustainability along the Rio Grande in West Texas: changes in salt loading and organic nutrients due to farming practices

    NASA Astrophysics Data System (ADS)

    Cox, C. L.; Ganjegunte, G.; Borrok, D. M.; Lougheed, V.; Ma, L.; Jin, L.

    2011-12-01

    thus have higher salt loading, and that Cotton has a higher clay content. The EC values continuously increase from irrigation water to soil waters, suggesting that as water travels through the soil profile it increases in salinity. Consistent with this observation, cation concentrations in soil waters increased with depth. Therefore, the salts within the soils are mobilized during irrigation. 5TE sensors at all three depths in the field showed spikes in EC, and soil moisture during each period of flood irrigation. Data also suggests a lower bulk EC between irrigation periods which might result from a lower soil moisture content which doesn't solublize the salts. The carbonate- and gypsum- rich soils and surface water in the Rio Grande Basin change with intensity and amount of irrigation, addition of fertilizers, and other agricultural practices. Results from this project contribute to our understanding of salt loading and nutrient cycling in the vulnerable area of the Rio Grande Valley in West Texas.

  3. Consortium for research in elder self-neglect of Texas research: advancing the field for practitioners.

    PubMed

    Mosqueda, Laura; Brandl, Bonnie; Otto, Joanne; Stiegel, Lori; Thomas, Randolph; Heisler, Candace

    2008-11-01

    An external advisory board consisting of members from the fields of geriatric internal medicine, family practice geriatrics, criminal prosecution, civil law, police force, adult protective services, and victims advocacy was created to advise and guide the research conducted by the Consortium for Research in Elder Self-neglect of Texas (CREST). This panel of experts performed site visits and facilitated the research through responses to every-other-week fact sheets and quarterly conference calls. This paper provides the perspective of five of the board members regarding the research findings that were presented at the CREST National Conference in 2006. The discussions outline the successes of the CREST research, describe obstacles and the necessary next steps for continuance of the scientific exploration of this syndrome, and highlight the practice implications of the current and proposed research. PMID:19016972

  4. A unique Austin Chalk reservoir, Van field, Van Zandt County, Texas

    SciTech Connect

    Lowe, J.T. )

    1990-09-01

    Significant shallow oil production from the Austin Chalk was established in the Van field, Van Zandt County, in East Texas in the late 1980s. The Van field structure is a complexly faulted domal anticline created by salt intrusion. The Woodbine sands, which underlie the Austin Chalk, have been and continue to be the predominant reservoir rocks in the field. Evidence indicates that faults provided vertical conduits for migration of Woodbine oil into the Austin Chalk where it was trapped along the structural crest. The most prolific Austin Chalk production is on the upthrown side of the main field fault, as is the Woodbine. The Austin Chalk is a soft, white to light gray limestone composed mostly of coccoliths with some pelecypods. Unlike the Austin Chalk in the Giddings and Pearsall fields, the chalk at Van was not as deeply buried and therefore did not become brittle and susceptible to tensional or cryptic fracturing. The shallow burial in the Van field was also important in that it allowed the chalk to retain primary microporosity. The production comes entirely from this primary porosity. In addition to the structural position and underlying oil source from the Woodbine, the depositional environment and associated lithofacies are also keys to the reservoir quality in the Van field as demonstrated by cores from the upthrown and downthrown (less productive) sides of the main field fault. It appears that at the time of Austin Chalk deposition, the main field fault was active and caused the upthrown side to be a structural high and a more agreeable environment for benthonic organisms such as pelecypods and worms. The resulting bioturbation enhanced the reservoir's permeability enough to allow migration and entrapment of the oil. Future success in exploration for analogous Austin Chalk reservoirs will require the combination of a favorable environment of deposition, a nearby Woodbine oil source, and a faulted trap that will provide the conduit for migration.

  5. Secondary natural gas recovery in mature fluvial sandstone reservoirs, Frio Formation, Agua Dulce Field, South Texas

    SciTech Connect

    Ambrose, W.A.; Levey, R.A. ); Vidal, J.M. ); Sippel, M.A. ); Ballard, J.R. ); Coover, D.M. Jr. ); Bloxsom, W.E. )

    1993-09-01

    An approach that integrates detailed geologic, engineering, and petrophysical analyses combined with improved well-log analytical techniques can be used by independent oil and gas companies of successful infield exploration in mature Gulf Coast fields that larger companies may consider uneconomic. In a secondary gas recovery project conducted by the Bureau of Economic Geology and funded by the Gas Research Institute and the U.S. Department of Energy, a potential incremental natural gas resource of 7.7 bcf, of which 4.0 bcf may be technically recoverable, was identified in a 490-ac lease in Agua Dulce field. Five wells in this lease had previously produced 13.7 bcf from Frio reservoirs at depths of 4600-6200 ft. The pay zones occur in heterogeneous fluvial sandstones offset by faults associated with the Vicksburg fault zone. The compartments may each contain up to 1.0 bcf of gas resources with estimates based on previous completions and the recent infield drilling experience of Pintas Creek Oil Company. Uncontacted gas resources occur in thin (typically less than 10 ft) bypassed zones that can be identified through a computed log evaluation that integrates open-hole logs, wireline pressure tests, fluid samples, and cores. At Agua Dulce field, such analysis identified at 4-ft bypassed zone uphole from previously produced reservoirs. This reservoir contained original reservoir pressure and flowed at rates exceeding 1 mmcf/d. The expected ultimate recovery is 0.4 bcf. Methodologies developed in the evaluation of Agua Dulce field can be successfully applied to other mature gas fields in the south Texas Gulf Coast. For example, Stratton and McFaddin are two fields in which the secondary gas recovery project has demonstrated the existence of thin, potentially bypassed zones that can yield significant incremental gas resources, extending the economic life of these fields.

  6. Aventura ranch field: A classic stratigraphic trap - James Lime, Van Zandt County, Texas

    SciTech Connect

    Jones, A.; Palmer, J.T. )

    1993-09-01

    Aventura Ranch field, found September 10, 1990, is the most recent significant James Lime discovery in the East Texas basin. Current estimates indicate recoverable reserves of 20 bcf of gas and 1.5 million bbl of condensate. The field represents a classic stratigraphic trap, formed by a facies change from downdip porous and permeable grainstones, terminating updip into carbonate mudstones, wackestones, and unrelated grainstones. The James Lime formation consists of poorly sorted, low-porosity lime wackestone/mudstones, and well-sorted reservoir lime grainstones. The reservoir consists of two facies: (1) skeletal grainstones, and (2) oolitic grainstones. The skeletal grainstones are interpreted as deposits adjacent to the James Lime reef core. The oolitic grainstones were deposited as high-energy shoals or bars in shallow, agitated water, possible paralleling the skeletal grainstones adjacent of the reef. Both interparticle and intraparticle porosity are present in the grainstone facies. Microporosity also is evident and is responsible for suppressing most of the induction log resistivity throughout the field. Resistivity as low as 1.5 ohms is found to be hydrocarbon productive. Subsequent to the development of the Fairway field, a large James Lime stratigraphic trap had been sought for many years, resulting in only the minor discovery of North Athens field. Several dry holes had been drilled amazingly close to the currently productive area. Perseverance and persistence finally paid off with the discovery of Aventura Ranch field. Currently, the field is producing 6 million ft[sup 3] of gas and 425 bbl of condensate a day.

  7. Trace contraband detection field-test by the south Texas specialized crimes and narcotics task force.

    SciTech Connect

    Hannum, David W.; Shannon, Gary W.

    2006-04-01

    This report describes the collaboration between the South Texas Specialized Crimes and Narcotics Task Force (STSCNTF) and Sandia National Laboratories (SNL) in a field test that provided prototype hand-held trace detection technology for use in counter-drug operations. The National Institute of Justice (NIJ)/National Law Enforcement and Corrections Technology Center (NLECTC)/Border Research and Technology Center (BRTC) was contacted by STSCNTF for assistance in obtaining cutting-edge technology. The BRTC created a pilot project for Sandia National Laboratories (SNL) and the STSCNTF for the use of SNLs Hound, a hand-held sample collection and preconcentration system that, when combined with a commercial chemical detector, can be used for the trace detection of illicit drugs and explosives. The STSCNTF operates in an area of high narcotics trafficking where methods of concealment make the detection of narcotics challenging. Sandia National Laboratories (SNL) Contraband Detection Department personnel provided the Hound system hardware and operational training. The Hound system combines the GE VaporTracer2, a hand-held commercial chemical detector, with an SNL-developed sample collection and preconcentration system. The South Texas Task force reported a variety of successes, including identification of a major shipment of methamphetamines, the discovery of hidden compartments in vehicles that contained illegal drugs and currency used in drug deals, and the identification of a suspect in a nightclub shooting. The main advantage of the hand-held trace detection unit is its ability to quickly identify the type of chemical (drugs or explosives) without a long lag time for laboratory analysis, which is the most common analysis method for current law enforcement procedures.

  8. Combined geological and surface geochemical methods discovered Agaritta and Brady Creek Fields, Concho County, Texas

    SciTech Connect

    Saunders, D.F.; Burson, K.R.; Thompson, C.K. ); Brown, J.J. )

    1993-07-01

    From December 1987 to March 1991, 25 prospects in the lower King sand (Upper Pennsylvanian Cisco) play in Concho County, Texas, were tested by several operators. They used combinations of subsurface geology, reconnaissance airborne gas sensing, surface radiometrics, soil magnetic susceptibility, and soil-gas hydrocarbon measurements to define prospects. Six new King sand discoveries or extensions and three deeper Goen discoveries resulted in a 36% exploratory success rate. The total exploration and development cost was approximately $0.67/bbl of proven producing oil reserves. Final locations for the discovery wells on each of the nine successful prospects were selected primarily on the basis of combined subsurface geology and surface geochemical data. As examples, we present information about the discovery of Brady Creek and Agaritta fields. Agaritta field is one of the two largest of the new-field discoveries, with estimated proven producing recoverable reserves of 6 million bbl of oil. Its discovery was based on a combination of (1) regional subsurface geologic projection, (2) airborne hydrocarbon sensing, (3) interstitial soil-gas hydrocarbon data, (4) soil magnetic-susceptibility measurements, and (5) surface potassium and uranium concentrations measured by gamma-ray spectrometry.

  9. Case history--installation of high volume pumping equipment in Talco Field, Texas

    SciTech Connect

    Rose, J.D.; Etheridge, K.T.; Wilson, R.H.

    1982-09-01

    The paper presents a case history study of Exxon's high volume artificial lift program at Talco Field in Franklin and Titus Counties, Texas. The field, discovered in 1936, produces heavy crude oil from the Paluxy Sandstone at an approximate depth of 4200 feet. All wells required artificial lift installation soon after the field was discovered due to rapid salt water breakthrough. Primary recovery efficiency is expected to be only about 35 percent of the original oil in place, attributed to reservoir heterogeneity and the adverse water-oil mobility ratio. Through installation of high volume artificial lift equipment, current data indicate that significant additional recovery benefits may be realized. The paper details the practical experience Exxon has gained since the first high volume electric submersible pump was installed at Talco in 1974. Included are screening parameters used to optimize the selection of particular high volume artificial lift equipment. Also included are representative production flowstreams to quantify the additional recovery expected of typical electric submersible pump and large capacity beam pumping unit installations. An analysis of the incremental expenses and costs associated with electric submersible pumps and large capacity beam pumping units is presented. Also discussed are case production histories and operational problems encountered with actual installations.

  10. International Trade Seminar (Austin, Texas, December 2, 1988).

    ERIC Educational Resources Information Center

    Midland Coll., TX. Business and Economic Development Center.

    Selected presentations from a 1988 seminar on international trade hosted by Midland College (MC) are included in this report. Designed to direct west Texas businesses toward diversification and to prepare them for international trade and business opportunities, the seminar featured speakers in the field of international trade, including bank…

  11. Application of advanced reservoir characterization, simulation, and production optimization strategies to maximize recovery in slope and basin clastic reservoirs, west Texas (Delaware Basin). Annual progress report, March 31, 1995--March 31, 1996

    SciTech Connect

    Dutton, S.P.; Hovorka, S.D.; Cole, A.G.

    1996-08-01

    The objective of this Class III project is to demonstrate that detailed reservoir characterization of clastic reservoirs in basinal sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost-effective way to recover more of the original oil in place by strategic infill-well placement and geologically based field development. Reservoirs in the Delaware Mountain Group have low producibility (average recovery <14 percent of the original oil in place) because of a high degree of vertical and lateral heterogeneity caused by depositional processes and post-depositional diagenetic modification. Detailed correlations of the Ramsey sandstone reservoirs in Geraldine Ford field suggest that lateral sandstone continuity is less than interpreted by previous studies. The degree of lateral heterogeneity in the reservoir sandstones suggests that they were deposited by eolian-derived turbidites. According to the eolian-derived turbidite model, sand dunes migrated across the exposed shelf to the shelf break during sea-level lowstands and provided well sorted sand for turbidity currents or grain flows into the deep basin.

  12. New platform proposal for West Troll gas field

    SciTech Connect

    Not Available

    1984-10-01

    The Condeep Skirt Pile described in this paper is a central fixed production platform which could offer greater topside flexibility as well as reduced settlement compared with other gravity platforms. The new design resembles a stretched version of the successful Condeep gravity platforms for medium water depths, with a multicell foundation and up to four shafts extended to carry the deck. This solution permits a more flexible topside layout with wider separation between the living quarters and hazardous areas. It also provides a larger volume in the shafts compared with a monotower for accomodating conductors and risers from the many satellite wells planned on West Troll and utilities.

  13. High-intensity geomagnetic field 'spike' observed at ca. 3000 cal BP in Texas, USA

    NASA Astrophysics Data System (ADS)

    Bourne, Mark D.; Feinberg, Joshua M.; Stafford, Thomas W.; Waters, Michael R.; Lundelius, Ernest; Forman, Steven L.

    2016-05-01

    By observing the fluctuations in direction and intensity of the Earth's magnetic field through time, we increase our understanding of the fluid motions of the Earth's outer core that sustain the geomagnetic field, the geodynamo. Recent archaeomagnetic studies in the Near East have found extremely rapid increases - 'spikes' - in geomagnetic field intensity at ca. 3000 yr cal BP. These observations have proved problematic for our current understanding of core-flow. However, until now, these geomagnetic spikes had not been observed outside of the Near East, where they have been preserved in metallurgical slag and fired, mud brick walls. We present a new, fully oriented, geomagnetic secular variation and relative palaeointensity (RPI) record for the last 17,000 yr from Hall's Cave, Texas, whose complete, >3.8 m thick sedimentary sequence spans from the present to 16 , 850 ± 110 RC yr BP (Modern to 20,600 cal BP). Within the stable, cool climate of the cave, pedogenic and bioturbation processes are negligible to non-existent, thereby limiting post-depositional physical and geochemical alteration of the magnetic record. The sub-aerial and subterranean setting of the sedimentary sequence in Hall's Cave enabled us to collect oriented palaeomagnetic cubes from a previously excavated stratigraphic section. The palaeomagnetic samples yielded high-quality vectors. An age model for the sequence, determined using 15 AMS 14C-dates on individual bones from microvertebrates, was combined with the palaeomagnetic data to construct a secular variation record. The record is in broad agreement with predictions by Holocene field models for the site's location. However, starting ca. 3000 yr ago, the RPI data indicate an almost four-fold increase in geomagnetic field intensity lasting several hundred years. This record presents well-dated evidence, obtained using conventional techniques, for the existence of a geomagnetic intensity spike in North America that is contemporaneous with the

  14. 33 CFR 165.804 - Snake Island, Texas City, Texas; mooring and fleeting of vessels-safety zone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Snake Island, Texas City, Texas... Guard District § 165.804 Snake Island, Texas City, Texas; mooring and fleeting of vessels—safety zone... Turning Basin west of Snake Island; (3) The area of Texas City Channel from the north end of the...

  15. 33 CFR 165.804 - Snake Island, Texas City, Texas; mooring and fleeting of vessels-safety zone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Snake Island, Texas City, Texas... Guard District § 165.804 Snake Island, Texas City, Texas; mooring and fleeting of vessels—safety zone... Turning Basin west of Snake Island; (3) The area of Texas City Channel from the north end of the...

  16. 33 CFR 165.804 - Snake Island, Texas City, Texas; mooring and fleeting of vessels-safety zone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Snake Island, Texas City, Texas... Guard District § 165.804 Snake Island, Texas City, Texas; mooring and fleeting of vessels—safety zone... Turning Basin west of Snake Island; (3) The area of Texas City Channel from the north end of the...

  17. 33 CFR 165.804 - Snake Island, Texas City, Texas; mooring and fleeting of vessels-safety zone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Snake Island, Texas City, Texas... Guard District § 165.804 Snake Island, Texas City, Texas; mooring and fleeting of vessels—safety zone... Turning Basin west of Snake Island; (3) The area of Texas City Channel from the north end of the...

  18. B. C. Canyon field, Howard County, Texas: An ancient analogy to modern tropical tower karst terrains

    SciTech Connect

    Mozynski, D.C.; Reid, A.M. )

    1992-04-01

    Late in the early deposition of sediments in Canyon field, a series of glacio-eustatically controlled sea level lowstands resulted in a carbonate buildup seaward of the Horseshoe Atoll in Howard County, Texas. The resulting satellite reef tract consists of fringing boundstone; high-energy shelf grainstones; lower energy shelf packstones and wackestones; and thin, highstand, black shales and mudstones. The original extent and thickness of deposits were extensively modified during karstification coincident with successive sea level lowstands. The resulting paleotopographic landforms appear to be similar to tower karst features of Puerto Rico. During the beginning of each sea level highstand, the paleoterrain was modified by erosion. The basinal foreshelf conglomerates resulting from initial highstand erosion contain dipping strata that commonly can be detected by the dipmeter tool. The mechanism for the formation of these strata may be depositional or the result of diagenetic alteration of the rock fabric in the burial environment. Using dipmeter data, an uneconomic producer has been offset by one of the better producing wells in the field.

  19. Geochemistry of Eagle Ford group source rocks and oils from the first shot field area, Texas

    USGS Publications Warehouse

    Edman, Janell D.; Pitman, Janet K.

    2010-01-01

    Total organic carbon, Rock-Eval pyrolysis, and vitrinite reflectance analyses performed on Eagle Ford Group core and cuttings samples from the First Shot field area, Texas demonstrate these samples have sufficient quantity, quality, and maturity of organic matter to have generated oil. Furthermore, gas chromatography and biomarker analyses performed on Eagle Ford Group oils and source rock extracts as well as weight percent sulfur analyses on the oils indicate the source rock facies for most of the oils are fairly similar. Specifically, these source rock facies vary in lithology from shales to marls, contain elevated levels of sulfur, and were deposited in a marine environment under anoxic conditions. It is these First Shot Eagle Ford source facies that have generated the oils in the First Shot Field. However, in contrast to the generally similar source rock facies and organic matter, maturity varies from early oil window to late oil window in the study area, and these maturity variations have a pronounced effect on both the source rock and oil characteristics. Finally, most of the oils appear to have been generated locally and have not experienced long distance migration. 

  20. Single-well evaluation program for micellar/polymer recovery, Main and 99 West Pools, West Coyote Field, California

    SciTech Connect

    Holland, K.M.; Porter, L.T.

    1983-10-01

    The Main and 99 West Pools of the West Coyote Field were selected as promising candidates for a micellar-polymer recovery project. Waterfloods initiated in 1961 are nearing their economic limit, with a current water-oil ratio of 45. Well MC 374 was drilled in a watered-out portion of the Main and 99 West reservoirs to accomplish an evaluation program with the following objectives: provide data for an improved geological model; estimate current oil in place; and determine the effectiveness of micellarpolymer chemicals in displacing residual oil. MC 374 was extensively cored and logged to provide the necessary geological and reservoir data. A multi-well interference test was conducted to confirm reservoir continuity near the test well. Displacement tests were run in two intervals with micellar-polymer chemicals. Oil saturations in the near-wellbore area were measured before and after the displacement tests using log-inject-log and single-well-tracer techniques. An extended polymer injectivity test was conducted in one of the intervals.

  1. Consolidation of geologic studies of geopressured-geothermal resources in Texas: Barrier-bar tidal-channel reservoir facies architecture, Jackson Group, Prado field, South Texas; Final report

    SciTech Connect

    Seni, S.J.; Choh, S.J.

    1994-01-01

    Sandstone reservoirs in the Jackson barrier/strandplain play are characterized by low recovery efficiencies and thus contain a large hydrocarbon resource target potentially amenable to advanced recovery techniques. Prado field, Jim Hogg County, South Texas, has produced over 23 million bbl of oil and over 32 million mcf gas from combination structural-stratigraphic traps in the Eocene lower Jackson Group. Hydrocarbon entrapment at Prado field is a result of anticlinal nosing by differential compaction and updip pinch-out of barrier bar sandstone. Relative base-level lowering resulted in forced regression that established lower Jackson shoreline sandstones in a relatively distal location in central Jim Hogg County. Reservoir sand bodies at Prado field comprise complex assemblages of barrier-bar, tidal-inlet fill, back-barrier bar, and shoreface environments. Subsequent progradation built the barrier-bar system seaward 1 to 2 mi. Within the barrier-bar system, favorable targets for hydrocarbon reexploration are concentrated in tidal-inlet facies because they possess the greatest degree of depositional heterogeneity. The purpose of this report is (1) to describe and analyze the sand-body architecture, depositional facies variations, and structure of Prado field, (2) to determine controls on distribution of hydrocarbons pertinent to reexploration for bypassed hydrocarbons, (3) to describe reservoir models at Prado field, and (4) to develop new data affecting the suitability of Jackson oil fields as possible candidates for thermally enhanced recovery of medium to heavy oil.

  2. ADVANCED FRACTURING TECHNOLOGY FOR TIGHT GAS: AN EAST TEXAS FIELD DEMONSTRATION

    SciTech Connect

    Mukul M. Sharma

    2005-03-01

    The primary objective of this research was to improve completion and fracturing practices in gas reservoirs in marginal plays in the continental United States. The Bossier Play in East Texas, a very active tight gas play, was chosen as the site to develop and test the new strategies for completion and fracturing. Figure 1 provides a general location map for the Dowdy Ranch Field, where the wells involved in this study are located. The Bossier and other tight gas formations in the continental Unites States are marginal plays in that they become uneconomical at gas prices below $2.00 MCF. It was, therefore, imperative that completion and fracturing practices be optimized so that these gas wells remain economically attractive. The economic viability of this play is strongly dependent on the cost and effectiveness of the hydraulic fracturing used in its well completions. Water-fracs consisting of proppant pumped with un-gelled fluid is the type of stimulation used in many low permeability reservoirs in East Texas and throughout the United States. The use of low viscosity Newtonian fluids allows the creation of long narrow fractures in the reservoir, without the excessive height growth that is often seen with cross-linked fluids. These low viscosity fluids have poor proppant transport properties. Pressure transient tests run on several wells that have been water-fractured indicate a long effective fracture length with very low fracture conductivity even when large amounts of proppant are placed in the formation. A modification to the water-frac stimulation design was needed to transport proppant farther out into the fracture. This requires suspending the proppant until the fracture closes without generating excessive fracture height. A review of fracture diagnostic data collected from various wells in different areas (for conventional gel and water-fracs) suggests that effective propped lengths for the fracture treatments are sometimes significantly shorter than those

  3. Geological control on the reservoir characteristics of Olkaria West Geothermal Field, Kenya

    SciTech Connect

    Omenda, Peter A.

    1994-01-20

    The reservoir of the West Olkaria Geothermal Field is hosted within tuffs and the reservoir fluid is characterized by higher concentrations of reservoir CO{sub 2} (10,000-100,000 mg/kg) but lower chloride concentrations of about 200 mg/kg than the East and North East Fields. The West Field is in the outflow and main recharge area of the Olkaria geothermal system. Permeability is generally low in the West Field and its distribution is strongly controlled by the structures. Fault zones show higher permeability with wells drilled within the structures havin larger total mass outputs. However, N-S and NW-SE faults are mainly channels for cold water downflow into the reservoir. Well feeder zones occur mostly at lava-tuff contacts; within fractured lava flows and at the contacts of intrusives and host rocks.

  4. West Texas geothermal resource assessment. Part II. Preliminary utilization assessment of the Trans-Pecos geothermal resource. Final report

    SciTech Connect

    Gilliland, M.W.; Fenner, L.B.

    1980-01-01

    The utilization potential of geothermal resources in Trans-Pecos, Texas was assessed. The potential for both direct use and electric power generation were examined. As with the resource assessment work, the focus was on the Hueco Tanks area in northeastern El Paso County and the Presidio Bolson area in Presidio County. Suitable users of the Hueco Tanks and Presidio Bolson resource areas were identified by matching postulated temperature characteristics of the geothermal resource to the need characteristics of existing users in each resource area. The amount of geothermal energy required and the amount of fossil fuel that geothermal energy would replace were calculated for each of the users identified as suitable. Current data indicate that temperatures in the Hueco Tanks resource area are not high enough for electric power generation, but in at least part of the Presidio Bolson resource area, they may be high enough for electric power generation.

  5. The University of Texas Institute for Geophysics Marine Geology and Geophysics Field Course

    NASA Astrophysics Data System (ADS)

    Duncan, D.; Davis, M. B.; Goff, J. A.; Gulick, S. P. S.; McIntosh, K. D.; Saustrup, S., Sr.

    2014-12-01

    The University of Texas Institute for Geophysics, part of the Jackson School of Geosciences, annually offers a three-week marine geology and geophysics field course during the spring-summer intersession. The course provides hands-on instruction and training for graduate and upper-level undergraduate students in high-resolution seismic reflection, CHIRP sub-bottom profiling, multibeam bathymetry, sidescan sonar, several types of sediment coring, grab sampling, and the sedimentology of resulting seabed samples. Students participate in an initial three days of classroom instruction designed to communicate geological context of the field area along with theoretical and technical background on each field method. The class then travels to the Gulf Coast for a week of at-sea field work. Our field sites at Port Aransas, and Galveston, TX, and Grand Isle, LA, provide ideal locations for students to investigate coastal processes of the Gulf Coast and continental shelf through application of geophysical techniques in an exploratory mode. At sea, students assist with survey design and instrumentation set up while learning about acquisition parameters, data quality control, trouble-shooting, and safe instrument deployment and retrieval. In teams of four, students work in onshore field labs preparing sediment samples for particle size analysis and data processing. During the course's final week, teams return to the classroom where they integrate, interpret, and visualize data in a final project using industry-standard software such as Echos, Landmark, Caris, and Fledermaus. The course concludes with a series of final presentations and discussions in which students examine geologic history and/or sedimentary processes represented by the Gulf Coast continental shelf with academic and industry supporters. Students report a greater understanding of marine geology and geophysics through the course's intensive, hands-on, team approach and low instructor to student ratio (sixteen

  6. The University of Texas Institute for Geophysics Marine Geology and Geophysics Field Course

    NASA Astrophysics Data System (ADS)

    Davis, M. B.; Gulick, S. P.; Allison, M. A.; Goff, J. A.; Duncan, D. D.; Saustrup, S.

    2011-12-01

    The University of Texas Institute for Geophysics, part of the Jackson School of Geosciences, annually offers an intensive three-week marine geology and geophysics field course during the spring-summer intersession. Now in year five, the course provides hands-on instruction and training for graduate and upper-level undergraduate students in data acquisition, processing, interpretation, and visualization. Techniques covered include high-resolution seismic reflection, CHIRP sub-bottom profiling, multibeam bathymetry, sidescan sonar, several types of sediment coring, grab sampling, and the sedimentology of resulting seabed samples (e.g., core description, grain size analysis, x-radiography, etc.). Students seek to understand coastal and sedimentary processes of the Gulf Coast and continental shelf through application of these techniques in an exploratory mode. Students participate in an initial three days of classroom instruction designed to communicate geological context of the field area (which changes each year) along with theoretical and technical background on each field method. The class then travels to the Gulf Coast for a week of at-sea field work. In the field, students rotate between two small research vessels: one vessel, the 22' aluminum-hulled R/V Lake Itasca, owned and operated by UTIG, is used principally for multibeam bathymetry, sidescan sonar, and sediment sampling; the other, NOAA's R/V Manta or the R/V Acadiana, operated by the Louisiana Universities Marine Consortium, is used primarily for high-resolution seismic reflection, CHIRP sub-bottom profiling, multibeam bathymetry, gravity coring, and vibracoring. While at sea, students assist with survey design, learn instrumentation set up, acquisition parameters, data quality control, and safe instrument deployment and retrieval. In teams of three, students work in onshore field labs preparing sediment samples for particle size analysis and initial data processing. During the course's final week, teams

  7. Air injection project breathes fire into aging West Hackberry oil field

    SciTech Connect

    Duey, R.

    1996-02-01

    Amoco, the DOE and LSU seek more oil from Gulf Coast salt dome fields with air injection technique. The West Hackberry Field in Louisiana is a water-driven reservoir. By injecting air into the high-pressure, high-temperature reservoir rock, the water is backed down, allowing the oil to drain off the steeply dipped rock.

  8. Deep Wilcox structure and stratigraphy in Fandango field area, Zapata County, Texas

    SciTech Connect

    Levin, D.M.

    1983-09-01

    The Fandango field in Zapata County, Texas, is a new deep Wilcox trend extension. The deep Wilcox sands are commonly found at depths of 15,000 to 20,000 ft (4,500 to 6,100 m). Enough well log and seismic control now exists to make an accurate integrated interpretation of regional deep Wilcox structure and stratigraphy. Deep Wilcox structure and stratigraphy are controlled by regionally extensive shale anticlines. These shale uplifts control deep Wilcox sand distribution, create large anticlines, and cause regional growth faults which commonly influence local structure. Each regional uplift presents a new exploration frontier holding the promise of vast reserves in the deep Wilcox. The history of Frio-Vicksburg exploration is an analogy to the deep Wilcox trend today. It took 40 years to expand Frio exploration from shallow stratigraphic tramps down into the enormous reserves in the Gulf of Mexico, because each new fault-block extension was considered to mark the downdip limit of Frio production. This was, of course, not true and is not true in the deep Wilcox today. The deep Wilcox trend remains virtually unexplored and it is the author's belief that continued work will prove the existence of much more deep Wilcox potential than is currently thought to exist.

  9. Clay minerals as indicators for depositional environment in the south Hallettsville Field, Lavaca County, Texas

    SciTech Connect

    Freed, R.L.

    1980-01-01

    The South Hallettsville Field, Lavaca County, Texas, produces gas and condensate from Lower Wilcox sandstones and shales which have been interpreted as either channel turbidite deposits in outer-shelf to slope locations or as delta to pro-delta sands and muds. Thirteen core samples were analyzed by X-ray diffraction methods to determine whether a semiquantitative estimate of clay mineral content would aid in determining the depositional environment. Discrete illite, kaolinite, and chlorite are of particular interest because the presence of these minerals is interpreted as being due to original deposition. If a turbidity-type event occurred, the weight percents of nondiagenetic clays in this sequence should: (1) decrease significantly as the boundary is crossed between the shale and the overlying sandstone; and (2) gradually increase in progressively shallower samples within the sandstone. However, the weight percents for kaolinite and chlorite do not vary significantly; the illite content gradually decreases with shallower depths. This sequence is more compatible with a deltaic environment of deposition. 10 references.

  10. Deep Wilcox structure and stratigraphy in Fandango field area, Zapata County, Texas

    SciTech Connect

    Levin, D.M.

    1984-04-01

    The Fandango field in Zapata County, Texas, is a new deep Wilcox trend extension. The deep Wilcox sands are commonly found at depths of 15,000-20,000 ft (4500-6100 m). Enough well log and seismic control exists to make an accurate integrated interpretation of regional deep Wilcox structure and stratigraphy. Deep Wilcox structure and stratigraphy are controlled by regionally extensive shale anticlines. These shale uplifts control deep Wilcox sand distribution, create large anticlines, and cause regional growth faults which frequently influence local structure. Each regional uplift presents a new exploration frontier holding the promise of vast reserves in the deep Wilcox. The history of Frio-Vicksburg exploration is analogous to the deep Wilcox trend of today. It took 40 years to expand Frio exploration from shallow stratigraphic traps down into enormous reserves in the Gulf of Mexico, because each new fault block extension was considered to mark the downdip limit of Frio production. This assumption was not true, and is not true in the deep Wilcox today. The deep Wilcox trend remains virtually unexplored, and it is my belief that continued work will prove the existence of much more deep Wilcox potential than is currently thought to exist.

  11. Modeling surface deformation due to CO2 injection at an enhanced oil recovery field in Texas

    NASA Astrophysics Data System (ADS)

    Yang, Q.; Abdollahzadeh, M.; Dixon, T. H.; Malservisi, R.; Hosseini, S.

    2013-12-01

    The Geodesy Laboratory at the University of South Florida has operated 3 C-GPS stations at an enhanced oil recovery field in Texas since October 2011. Our GPS sites recorded vertical uplift during the injection phase when the reservoir was initially pressurized, and localized subsidence in phase with reservoir pressure after oil extraction started. In this study, we use analytical and numerical models to better understand the small-scale surface deformation observed by GPS due to CO2 injection. First, we use an analytical model of a pressurized horizontal circular crack in an elastic half-space to fit the surface deformation data. Then, constrained by the analytical modeling results, we develop a poroelastic Finite Element Model (FEM) to investigate the influence of reservoir geometry and overlying stratigraphy on surface displacement. A sensitivity study is carried out to understand the effects of realistic geometry and material properties on surface deformation. Our preliminary results show that a poroelastic FEM can explain the location-dependant time delay between the injection and surface response.

  12. Bioavailability Assessment of a Contaminated Field Sediemtn from Patrick Bayou, Texas: TIE and Equilibrium Partitioning

    EPA Science Inventory

    Contaminated sediments are commonly found in urbanized harbors. Remediation is often necessary and diagnosing the cause of sediment toxicity becomes imperative. In the present study, sediments from Patrick Bayou, Texas were subjected to initial toxicity testing. All sediments ...

  13. An Updated Performance Assessment For A New Low-Level Radioactive Waste Disposal Facility In West Texas - 12192

    SciTech Connect

    Dornsife, William P.; Kirk, J. Scott; Shaw, Chris G.

    2012-07-01

    This Performance Assessment (PA) submittal is an update to the original PA that was developed to support the licensing of the Waste Control Specialists LLC Low-Level Radioactive Waste (LLRW) disposal facility. This update includes both the Compact Waste Facility (CWF) and the Federal Waste Facility (FWF), in accordance with Radioactive Material License (RML) No. R04100, License Condition (LC) 87. While many of the baseline assumptions supporting the initial license application PA were incorporated in this update, a new transport code, GoldSim, and new deterministic groundwater flow codes, including HYDRUS and MODFLOWSURFACT{sup TM}, were employed to demonstrate compliance with the performance objectives codified in the regulations and RML No. R04100, LC 87. A revised source term, provided by the Texas Commission on Environmental Quality staff, was used to match the initial 15 year license term. This updated PA clearly confirms and demonstrates the robustness of the characteristics of the site's geology and the advanced engineering design of the disposal units. Based on the simulations from fate and transport models, the radiation doses to members of the general public and site workers predicted in the initial and updated PA were a small fraction of the criterion doses of 0.25 mSv and 50 mSv, respectively. In a comparison between the results of the updated PA against the one developed in support of the initial license, both clearly demonstrated the robustness of the characteristics of the site's geology and engineering design of the disposal units. Based on the simulations from fate and transport models, the radiation doses to members of the general public predicted in the initial and updated PA were a fraction of the allowable 25 mrem/yr (0.25 m sievert/yr) dose standard for tens-of-thousands of years into the future. Draft Texas guidance on performance assessment (TCEQ, 2004) recommends a period of analysis equal to 1,000 years or until peak doses from the more

  14. Field Training Activities for Hydrologic Science in West Java, Indonesia

    NASA Astrophysics Data System (ADS)

    Agustina, C.; Fajri, P. N.; Fathoni, F.; Gusti, T. P.; Harifa, A. C.; Hendra, Y.; Hertanti, D. R.; Lusiana, N.; Rohmat, F. I.; Agouridis, C.; Fryar, A. E.; Milewski, A.; Pandjaitan, N.; Santoso, R.; Suharyanto, A.

    2013-12-01

    In hydrologic science and engineering, one challenge is establishing a common framework for discussion among workers from different disciplines. As part of the 'Building Opportunity Out of Science and Technology: Helping Hydrologic Outreach (BOOST H2O)' project, which is supported by the U.S. Department of State, nine current or recent graduate students from four Indonesian universities participated in a week of training activities during June 2013. Students had backgrounds in agricultural engineering, civil and environmental engineering, water resources engineering, natural resources management, and soil science. Professors leading the training, which was based at Bogor Agricultural University (IPB) in west Java, included an agricultural engineer, civil engineers, and geologists. Activities in surface-water hydrology included geomorphic assessment of streams (measuring slope, cross-section, and bed-clast size) and gauging stream flow (wading with top-setting rods and a current meter for a large stream, and using a bucket and stopwatch for a small stream). Groundwater-hydrology activities included measuring depth to water in wells, conducting a pumping test with an observation well, and performing vertical electrical soundings to infer hydrostratigraphy. Students also performed relatively simple water-quality measurements (temperature, electrical conductivity, pH, and alkalinity) in streams, wells, and springs. The group analyzed data with commercially-available software such as AQTESOLV for well hydraulics, freeware such as the U.S. Geological Survey alkalinity calculator, and Excel spreadsheets. Results were discussed in the context of landscape position, lithology, and land use.

  15. Reservoir heterogeneity in middle Frio fluvial sandstones: Case studies in Seeligson field, Jim Wells County, Texas

    SciTech Connect

    Jirik, L.A. )

    1990-09-01

    Detailed evaluation of middle Frio (Oligocene) fluvial sandstones reveals a complex architectural style potentially suited to the addition of gas reserves through recognition of poorly drained reservoir compartments and bypassed gas zones. Seeligson field is being studied as part of a Gas Research Institute/US Department of Energy/State of Texas-sponsored program, with the cooperation of Oryx Energy Company and Mobil Exploration and Producing US, Inc. Four reservoirs, Zones 15, 16D, 16E, and 19C, were studied in a 20 mi{sup 2} area within Seeligson field. Collectively, these reservoirs have produced more than 240 bcf of gas from wells within the study area. Detailed electric log correlation of individual reservoirs enabled subdivision of aggregate producing zones into component genetic units. Cross sections, net-sandstone maps, and log-facies maps were prepared to illustrate depositional style, sand-body geometry, and reservoir heterogeneity. Zones 15 and 19C are examples of laterally stacked fluvial architecture. Individual channel-fill sandstones range from 10 to 50 ft thick, and channel widths are approximately 2,500 ft. Crevasse-splay sandstones may extend a few thousand feet from the main channel system. Multiple, overlapping channel and splay deposits commonly form sand-rich belts that result in leaky reservoir compartments that may be incompletely drained. Zones 16D and 16E are examples of vertically stacked fluvial architecture, with discrete, relatively thin and narrow channel and splay sandstones generally encased within floodplain muds. This architectural style is likely to form more isolated reservoir compartments. Although all of these reservoirs are currently considered nearly depleted, low-pressure producers, recent well completions and bottomhole pressure data indicate that untapped or poorly drained compartments are being encountered.

  16. 2014: A Record-Breaking Year for West Nile Virus Positive Mosquito Pools in Harris County and the City of Houston, Texas.

    PubMed

    Randle, Yvonne H; Freeman, Cheryl Battle; Jackson, Monique; Reyna, Martin; Debboun, Mustapha

    2016-01-01

    In the 14 years since the emergence of West Nile virus (WNV) in Harris County and the city of Houston, Texas, the number of mosquitoes infected with the virus has fluctuated with several high and low count years. During this 14-year period, mosquito surveillance operational areas in Harris County were expanded from 248 to 268 and the distribution of the virus activity in mosquitoes varied from year to year. Operational areas with WNV infected mosquitoes increased from 137 in 2002 to 197 in 2006, decreased to 71 areas in 2007, and to an all-time low of 18 in 2008. The number increased to 78 areas in 2009, 96 in 2010, 133 in 2011, and 177 in 2012, but fell to 73 in 2013. However, 234 areas were confirmed in 2014, and only 138 in 2015. The WNV transmission was high in 2002 with 227 WNV positive mosquito pools. The number of positive mosquitoes remained elevated for a number of years and then declined from 2007 to 2010. Three record high years for WNV activity were: 2005, 2006, and 2011 with 698, 838, and 605 confirmed positive mosquito pools, respectively. Viral activity declined in 2012, followed by a marked decline in 2013 with only 147 WNV positive mosquito pools. In 2014, a record-breaking number of 1,286 WNV positive mosquito pools were confirmed in Harris County and the city of Houston, the most ever in a single season, while 406 were confirmed in 2015. PMID:27613203

  17. Host feeding pattern of Culex quinquefasciatus (Diptera: Culicidae) and its role in transmission of West Nile virus in Harris County, Texas.

    PubMed

    Molaei, Goudarz; Andreadis, Theodore G; Armstrong, Philip M; Bueno, Rudy; Dennett, James A; Real, Susan V; Sargent, Chris; Bala, Adilelkhidir; Randle, Yvonne; Guzman, Hilda; Travassos da Rosa, Amelia; Wuithiranyagool, Taweesak; Tesh, Robert B

    2007-07-01

    The vertebrate hosts of 672 blood-engorged Culex quinquefasciatus Say, collected in Harris County, Texas, during 2005, were identified by nucleotide sequencing PCR products of the cytochrome b gene. Analysis revealed that 39.1% had acquired blood from birds, 52.5% from mammals, and 8.3% were mixed avian and mammalian blood meals. Most frequent vertebrate hosts were dog (41.0%), mourning dove (18.3%), domestic cat (8.8%), white-winged dove (4.3%), house sparrow (3.2%), house finch (3.0%), gray catbird (3.0%), and American robin (2.5%). Results are interpreted in conjunction with concurrent avian and mosquito West Nile virus (WNV) surveillance activities in Harris County. We conclude that Cx. quinquefasciatus is an opportunistic feeder and principal mosquito vector of WNV in this metropolitan area; however, transmission by other mosquito species or by other modes of infection, such as ingestion, must account for the high WNV infection rates among local blue jays and American crows. PMID:17620633

  18. Depositional and diagenetic controls on porosity permeability and oil production in McFarland/Magutex (Queen) reservoirs, Andrews County, west Texas

    SciTech Connect

    Holtz, M.H. )

    1991-03-01

    The McFarland/Magutex Queen reservoir complex lies along the northeastern edge of the Central basin platform in the west Texas Permian basin and produces oil from the Permian Queen Formation. Current production from this complex totals 42 million stock-tank barrels (MMSTB) of an estimated 219 MMSTB of original oil in place, with an estimated 90 MMSTB of remaining mobile oil (RMO). The gross pay interval contains two parasequences consisting of progradational, 30-ft-thick, upward-shoaling facies packages. Facies include shoreface, mixed tidal channel and intertidal flat, and supratidal. Elongate shoreface facies are characterized by poorly consolidated, massive to thinly laminated sandstones. The supratidal facies, which act as permeability barriers, are characterized by algal-laminated dolostone and nodular, laminated, and massive anhydrite containing halite and gypsum pseudomorphs. Highest production and the largest amount of the 90 MMSTB of RMO is associated with the shoreface and tidal-channel facies. Bulk pore volume storage capacity and permeability are also highest within these two facies. Sandstones are arkosic, containing anhydrite and dolomite cements. Accessory minerals are clays, authigenic feldspar, and dolomite. Three main pore types are recognized: interparticle, moldic and intraconstituent, and micropores. Moldic and intraconstituent porosity is associated with leached feldspars and anhydrite cement dissolution. Microporosity is associated with syndepositional, grain-coating corrensite, dissolution-enhanced feldspar cleavage planes, and authigenic multifaceted dolomite. Microporosity derived from clays and dolomite is formed preferentially in tidal-channel and intertidal flat facies.

  19. A retrospective study of septic arthritis in a tertiary hospital in West Texas with high rates of methicillin-resistant Staphylococcus aureus infection.

    PubMed

    Lim, Sian Yik; Pannikath, Deepa; Nugent, Kenneth

    2015-07-01

    Septic arthritis is an important concern for rheumatologists in the evaluation of joint disease. Very few studies have addressed the microbiologic epidemiology and outcomes of septic arthritis in the USA since the year 2000. We performed a retrospective study of septic arthritis in a tertiary hospital in West Texas from the year 2000 to 2013. We recorded data on patient demographics, microbiologic etiology, treatment patterns, and outcomes. The most common causative organisms were Staphylococcus aureus and Streptococcus spp. Methicillin-resistant Staphylococcus aureus (MRSA) caused septic arthritis in 22.6 % of the cases. MRSA septic arthritis was associated with low rates of adequate empiric antimicrobial therapy. The mortality due to sepsis in our study was 5.5 %. Patients with septic arthritis had a mean length of stay of 13.5 ± 12.1 days and required 2.1 ± 1.4 joint operations. Many patients (29.2 %) had readmissions due to complications, and these patients had high rates of home health utilization and transfers to other facilities post hospital discharge. In our logistic regression analysis model, factors associated with poor outcomes in septic arthritis were MRSA, older age, and prosthetic joint infection. Septic arthritis is associated with significant mortality, morbidity, and health care costs, and more studies are needed to improve outcomes, especially considering the increasing rates of MRSA as the pathogen. PMID:25572838

  20. Astronaut Neil Armstrong studies rock samples during geological field trip

    NASA Technical Reports Server (NTRS)

    1969-01-01

    Astronaut Neil Armstrong, commander of the Apollo 11 lunar landing mission, studies rock samples during a geological field trip to the Quitman Mountains area near the Fort Quitman ruins in far west Texas.

  1. The role of refinery flaring events and bay breezes on a high surface ozone episode during the Houston, Texas DISCOVER-AQ field campaign

    NASA Astrophysics Data System (ADS)

    Loughner, C.; Follette-Cook, M. B.; Fried, A.; Pickering, K. E.

    2015-12-01

    The highest observed surface ozone concentrations in the Houston metropolitan area in 2013 occurred on September 25, which coincided with the Texas DISCOVER-AQ (Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality) field campaign. Surface ozone was elevated throughout the Houston metropolitan area with maximum 8-hour average ozone peaking along the western shore of Galveston Bay, reaching 124 ppbv, almost 50 ppbv above the current EPA standard of 75 ppbv. The NASA P-3B aircraft observed plumes from refinery flares west and northwest of Galveston Bay that were transported over the water. Continental air pollution from the north was transported into the Houston metropolitan area where it mixed with locally generated emissions. A bay breeze circulation formed causing pollutants that were transported out over the water in the morning to recirculate back inland where they mixed with freshly emitted pollution near the bay breeze convergence zone. The highest surface ozone concentrations were reported near the bay breeze front. This ozone episode will be presented using measurements made during the DISCOVER-AQ field campaign and a CMAQ model simulation with integrated source apportionment, which tracks the contribution of emissions source groups and regions on ozone concentrations.

  2. Consolidation of geologic studies of geopressured-geothermal resources in Texas: Barrier-bar tidal-channel reservoir facies architecture, Jackson Group, Prado Field, South Texas

    SciTech Connect

    Seni, S.J.; Choh, S.J.

    1993-09-01

    Sandstone reservoirs in the Jackson barrier/strandplain play are characterized by low recovery efficiencies and thus contain a large hydrocarbon resource target potentially amenable to advanced recovery techniques. Prado field, Jim Hogg County, South Texas, has produced over 23 million bbl of oil and over 32 million mcf gas from combination structural-stratigraphic traps in the Eocene lower Jackson Group. Hydrocarbon entrapment at Prado field is a result of anticlinal nosing by differential compaction and updip pinch-out of barrier bar sandstone. Relative base-level lowering resulted in forced regression that established lower Jackson shoreline sandstones in a relatively distal location in central Jim Hogg County. Reservoir sand bodies at Prado field comprise complex assemblages of barrier-bar, tidal-inlet fill, back-barrier bar, and shoreface environments. Subsequent progradation built the barrier-bar system seaward 1 to 2 mi. With the barrier-bar system, favorable targets for hydrocarbon reexploration are concentrated in tidal-inlet facies because they possess the greatest degree of depositional heterogeneity.

  3. Kitina: A West African intra-Albian field

    SciTech Connect

    Cornaggia, F.; Congo, S.A.; Agostino, M.

    1995-08-01

    Kitina field is located in Marine VII permit, offshore Congo. The field was discovered in 1991 by a joint venture composed of Agip Recherches Congo (operator), Hydrocongo and Chevron International Limited. The field is a structural four-way dip closure trap shaped as turtle-back. Halokinetic movements are responsible for the structuring. The seismic imaging of the reservoir is affected by strong lateral velocity variations caused by different sedimentation across the paleo-shelf edge in the post-Albian sequence. One pass 3D poststack depth migration, performed with a velocity field obtained by means of geostatistical integration of 2D seismic and wellbore velocities, achieved a good compromise between high dip reflector imaging and depths at well location. Three main reservoirs of lower Albian age exist between -2100 and -3100m. They are separated by tight mudstones which act as intraformational seal. Seismic trace inversion improved the resolution of petrophysical variations in some of the field reservoirs, which have the following characteristics (from top to bottom): reservoir 2A is composed of bioclastic and oolitic packstone-grainstone laid down during regional regressive phase in insulated offshore bars on the crest of structural high. Early diagenetic phenomena lead to the development of world class permeability framework. Reservoir 1A-1B are composed of sandstone bodies which were deposited as shoreface to offshore bars during short-term regressive pulse. The 1A-1B reservoir, are embedded in mudstones deposited during long lasting phases of relative high stand in relatively deep offshore setting characterised by high, halokinetic driven subsidence.

  4. Geologic description of middle Devonian Chert Reservoir, Block 31 field, Crane County, Texas

    SciTech Connect

    Ebanks, W.J. Jr.

    1988-01-01

    Block 31 field is a large anticlinal structure that produces from six pay zones. The first miscible gas-injection enhanced oil recovery project has been operated by ARCO since 1952 in the middle Devonian reservoir, which is the main producing interval in the field. The middle Devonian unit was deposited as a siliceous, calcareous ooze in a basin-slope environment in the ancient Tobosa basin. Sedimentation buried earlier fault blocks, as the slope deposits aggraded and prograded mainly from the west and south. Subsequent diagenesis converted the ooze into calcareous chert. Reservoir quality of the chert depends on degree of compaction and quartz cementation. Gray, dense, glassy chert at the base of the sequence is nonporous except for small, incipient fractures in the brittle matrix. Creamy white, evenly laminated, microporous, calcareous chert, which alternates with and overlies the dense chert in the lower half of the middle Devonian interval, has porosity of 10-30% and permeability as great as 10 md. The upper half of the reservoir interval consists mainly of light-gray and white, partially porous, heterogeneous, calcareous chert. This rock type has porosity of 5-20%, but permeability is usually less than 3 md. Patchy silica cement, discontinuous low-permeability laminae, and thin beds of dense limestone reduce its effectiveness as a reservoir.

  5. Childhood Trauma Training in the West Bank and Gaza Strip: A Field Visit Report

    ERIC Educational Resources Information Center

    Mobayed, Mamoun

    2004-01-01

    Post traumatic stress disorder is the psychological reaction to various traumas. It is common among children living in war zones or conflict regions. This paper describes a field visit to train mental health professionals in the West Bank and Gaza Strip on how to help traumatised children.

  6. Teaching Soil Science and Ecology in West Siberia: 17 Years of Field Courses

    ERIC Educational Resources Information Center

    Siewert, Christian; Barsukov, Pavel; Demyan, Scott; Babenko, Andrey; Lashchinsky, Nikolay; Smolentseva, Elena

    2014-01-01

    Since 1995, soil-ecological field courses across climatic zones in West Siberia have been organized by scientists from Russia and Germany to meet growing demands for better land use practices. They are focused on virgin landscapes and soils undisturbed by anthropogenic influences to facilitate the learning processes by excluding concealing changes…

  7. Nonexplosive and explosive magma/wet-sediment interaction during emplacement of Eocene intrusions into Cretaceous to Eocene strata, Trans-Pecos igneous province, West Texas

    USGS Publications Warehouse

    Befus, K.S.; Hanson, R.E.; Miggins, D.P.; Breyer, J.A.; Busbey, A.B.

    2009-01-01

    Eocene intrusion of alkaline basaltic to trachyandesitic magmas into unlithified, Upper Cretaceous (Maastrichtian) to Eocene fluvial strata in part of the Trans-Pecos igneous province in West Texas produced an array of features recording both nonexplosive and explosive magma/wet-sediment interaction. Intrusive complexes with 40Ar/39Ar dates of ~ 47-46??Ma consist of coherent basalt, peperite, and disrupted sediment. Two of the complexes cutting Cretaceous strata contain masses of conglomerate derived from Eocene fluvial deposits that, at the onset of intrusive activity, would have been > 400-500??m above the present level of exposure. These intrusive complexes are inferred to be remnants of diatremes that fed maar volcanoes during an early stage of magmatism in this part of the Trans-Pecos province. Disrupted Cretaceous strata along diatreme margins record collapse of conduit walls during and after subsurface phreatomagmatic explosions. Eocene conglomerate slumped downward from higher levels during vent excavation. Coherent to pillowed basaltic intrusions emplaced at the close of explosive activity formed peperite within the conglomerate, within disrupted Cretaceous strata in the conduit walls, and within inferred remnants of the phreatomagmatic slurry that filled the vents during explosive volcanism. A younger series of intrusions with 40Ar/39Ar dates of ~ 42??Ma underwent nonexplosive interaction with Upper Cretaceous to Paleocene mud and sand. Dikes and sills show fluidal, billowed, quenched margins against the host strata, recording development of surface instabilities between magma and groundwater-rich sediment. Accentuation of billowed margins resulted in propagation of intrusive pillows into the adjacent sediment. More intense disruption and mingling of quenched magma with sediment locally produced fluidal and blocky peperite, but sufficient volumes of pore fluid were not heated rapidly enough to generate phreatomagmatic explosions. This work suggests that

  8. Spatiotemporal relationships among Late Pennsylvanian plant assemblages: Palynological evidence from the Markley Formation, West Texas, U.S.A

    PubMed Central

    Looy, Cindy V.; Hotton, Carol L.

    2014-01-01

    The Pennsylvanian lowlands of western Pangea are best known for their diverse wetland floras of arborescent and herbaceous ferns, and arborescent horsetails and clubmosses. In apparent juxtaposition, a very different kind of flora, dominated by a xerophilous assemblage of conifers, taeniopterids and peltasperms, is occasionally glimpsed. Once believed to represent upland or extrabasinal floras from well-drained portions of the landscape, these dryland floras more recently have been interpreted as lowland assemblages growing during drier phases of glacial/interglacial cycles. Whether Pennsylvanian dryland and wetland floras were separated spatially or temporally remains an unsettled question, due in large part to taphonomic bias toward preservation of wetland plants. Previous paleobotanical and sedimentological analysis of the Markley Formation of latest Pennsylvanian (Gzhelian) age, from north central Texas, U.S.A, indicates close correlation between lithofacies and distinct dryland and wetland megaflora assemblages. Here we present a detailed analysis one of those localities, a section unusual in containing abundant palynomorphs, from the lower Markley Formation. Paleobotanical, palynological and lithological data from a section thought to represent a single interglacial/glacial phase are integrated and analyzed to create a complex picture of an evolving landscape. Megafloral data from throughout the Markley Formation show that conifer-dominated dryland floras occur exclusively in highly leached kaolinite beds, likely eroded from underlying soils, whereas a mosaic of wetland floras occupy histosols, ultisols, and fluvial overbank deposits. Palynological data largely conform to this pattern but reveal a more complex picture. An assemblage of mixed wetland and dryland palynofloral taxa is interpolated between a dryland assemblage and an overlying histosol containing wetland taxa. In this section, as well as elsewhere in the Markley Formation, kaolinite and overlying

  9. Middle Jurassic sand reservoirs of Tazovskoe field (West Siberia)

    NASA Astrophysics Data System (ADS)

    Kurasov, I. A.

    2012-12-01

    Perspectives of Tazovskoe field Jurassic strata development are associated with lithological and mineralogical characteristics of reservoirs, which are the main reserve of the region, because of the high rate of depletion of the most prolific Cenomanian gas pools. Tazovskoye field is multibedded and is unique in terms of hydrocarbon reserves. Middle Jurassic strata occur everywhere and are represented by rocks of the Tyumenskaya formation, comprising layers J2 - J5. The producing horizons are composed of sandstones, sandy siltstones, cemented by shaly-carbonate cement mass. According to laboratory data, the Jurassic reservoirs are characterized by a wide range of porosity (up to 22.5%) and mainly low permeability (up to 2 mD), except for a few samples of J3 reservoir with permeability up to 100-150 mD. Test objects were the core samples taken from 7 intervals of the well T-83 and logging data from 4 intervals of wells 73, 93 in the Tazovskoye field. Depth and core recovery from T-83 well of the Tazovskoye field are shown in Table 1. Total linear core recovery from the Jurassic strata was 79.4 m. Late Bajocian-Bathonian alluvial-lacustrine strata compose the first regressive cycle of sedimentation in the Tazovskoye field. They are represented by alternating thin sandy, siltstone-sandy, siltstone, shaly-siltstone, siltstone-shaly, and shaly rocks with coal interbeds. They include three main productive formations: J2, J3 and J4. Above in the vertical section, the Upper Jurassic rocks occur, while lower, basal strata of the Callovian stage overlay them with a distinct unconformity. In the Upper Jurassic time, the main transgression phase of the Jurassic period occurred over the whole territory of the Western Siberia. These strata are built by non-uniform alternating sandstones, siltstones and shales with coal interbeds of the continental genesis (alluvial-lacustrine); The reservoirs contain cyclites that as a rule have binary structure, less often - ternary structure

  10. South Texas yields huge gas discovery

    SciTech Connect

    Doughtie, D. )

    1994-09-01

    One of the largest onshore gas discoveries in the lower 48 states in the last 20 years proves that large world class standard reserves still exist in the Gulf Coast onshore Bob West field, located in South Texas, is one of the largest onshore continental US gas discoveries in recent history. Sanchez-O'Brien Oil and Gas Corp., Tesoro Exploration and Production, Coastal Corp. and Enercorp Resources will be primary developers of the field which consists of 24 producing horizons. This article discusses the field's development history, structure and stratigraphy, and drilling and completion activities.

  11. 3-D Monarch reservoir modelling as a development tool: West Salym field, Western Siberia, Russia

    SciTech Connect

    Ainsworth, R.B.; Van Kuyk, A.; Van Lieshout, J.

    1996-12-31

    The Salym fields are located in the central part of the West Siberia basin. The basin developed during the Triassic and contains an almost complete stratigraphic succession from the Jurassic to the Quaternary. The main oil reserves in the Salym fields are located in the Lower Cretaceous proprading deltaic complex. The principal reservoir section in the West Salym field is interpreted as marginal marine. Shoreface, mouthbar, fluvial channel and crevasse-splay subenvironments are recognised. Due to this range of depositional environments and average (exploration) well spacing of 5 km, 3-D modelling of depositional geometries is essential to determine the reservoir architecture and reservoir property trends prior to full-scale field development.

  12. 3-D Monarch reservoir modelling as a development tool: West Salym field, Western Siberia, Russia

    SciTech Connect

    Ainsworth, R.B.; Van Kuyk, A.; Van Lieshout, J. )

    1996-01-01

    The Salym fields are located in the central part of the West Siberia basin. The basin developed during the Triassic and contains an almost complete stratigraphic succession from the Jurassic to the Quaternary. The main oil reserves in the Salym fields are located in the Lower Cretaceous proprading deltaic complex. The principal reservoir section in the West Salym field is interpreted as marginal marine. Shoreface, mouthbar, fluvial channel and crevasse-splay subenvironments are recognised. Due to this range of depositional environments and average (exploration) well spacing of 5 km, 3-D modelling of depositional geometries is essential to determine the reservoir architecture and reservoir property trends prior to full-scale field development.

  13. Groundwater Modeling of Playa-Focused Recharge at the Southwestern Edge of the High Plains Aquifer in West Texas

    NASA Astrophysics Data System (ADS)

    Blainey, J.; Pickens, J. F.; grisak, G. E.; Holt, R. M.; Sigda, J.; Cook, S.; Hughes, E.

    2011-12-01

    Ongoing hydrogeologic investigations at a licensed low-level radioactive waste disposal site in Andrews County, Texas include monitoring of a groundwater system in Ogallala (Neogene), Antlers (Cretaceous), and Gatuna (Neogene/Quaternary) Formation sediments on the southwestern edge of the Southern High Plains physiographic province. The disposal site is underlain by unsaturated sands and gravels of these laterally contiguous sediments, informally termed the OAG. North of the site these sediments develop into the continuously saturated High Plains or Ogallala aquifer. Episodes of focused recharge to the OAG sediments have been observed during the last 9 years of groundwater level monitoring near small playas and topographic depressions that collect water after large precipitation events. During smaller precipitation events water is stored in the unsaturated zone and evapotranspired, predominately by mesquite, creosote and grasses. The climate is semi-arid with average evaporation rates far exceeding the estimated average annual precipitation of 15-16 inches/year. Monitoring at more than 250 wells in the OAG and environmental tracer studies confirm a conceptual model of playa-focused natural recharge to the groundwater system with little or no recharge occurring in inter-playa areas. The thickness of the OAG saturated sediments in the vicinity of the disposal sites ranges from 3 feet to 10 feet, with areas of discontinuous saturation away from areas of focused recharge. Environmental tracer studies show the groundwater in the OAG is poorly mixed and disconnected from regional groundwater flow further to the northeast. The disposal facilities are located over a structural high on the erosional surface of the Dockum Group, which immediately underlies the OAG sediments. This feature, referred to as the red bed ridge, is roughly coincident with the topographic divide between the High Plains and the Pecos Valley physiographic provinces and serves as a divide for

  14. Overburden and physical properties in the Marathon fold and thrust belt, West Texas, using conodont thermal maturity and vitrinite reflectance

    SciTech Connect

    Merrifield, G.T. Jr. . Center for Tectonophysics and Ocean Drilling Program)

    1992-01-01

    Distribution of Ordovician conodonts used in this study covers the southern two-thirds of the 2,400 km[sup 2] in the exposed thrust belt. Conodont color alteration indices (CAI) vary from 1.5 in the northwest to 3.0 eastward and 4.0--4.5 in the extreme southeast. These variations correlate with the 3 km increase in stratigraphic overburden from west to east in the accretionary rocks (Mississippian to Mid Pennsylvanian). In the western exposures, CAI increase southward to 2.0--2.5 within the Dagger Flat structural culmination and decrease to 1.0--1.5 further southward. Increased overburden due to structural thickening explains the CAI increase within the culmination. In the northern one-third of the exposed thrust belt, CAI from the Dimple formation (Mid Pennsylvanian) decrease northward from 2.5 to 1.0--1.5. Neither restored stratigraphic overburden nor local intrusions explain the elevated CAI value of 2.5. Extrapolation of the vitrinite reflectance gradient to the 0.2% value in a well less than 10 km east of this location indicate that between 2.5 and 4.3 km of overburden has been eroded. Structural thickening accounts for at least some of the elevated thermal maturity in this area. Vitrinite reflectance gradients are greater in the accretionary prism strata than in the older basinal facies (Upper Cambrian to Lower Mississippian). Since both facies are shale-rich, lithology alone plays little role in thermal conductivity and maturity variations. Instead, the age of compaction (and possibly undercompaction) relative to the times of thrusting subaerial exposure and erosion, and preservation of maximum thermal maturity are a more important factor. There is a slight discontinuous increase in the thermal maturity across the basal thrust, which is not explained by lithologic variations. Above and below the basal thrust, vitrinite gradients increase and is best explained by induced fracture permeability and flow of hot fluids.

  15. Utility of Thermal Sharpening Over Texas High Plains Irrigated Agricultural Fields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Irrigated crop production in the Texas High Plains (THP) is dependent on water extracted from the Ogallala Aquifer, an area suffering from sever water shortage. Water management in this area is therefore highly important. Thermal satellite imagery at high-temporal (~daily) and high-spatial (~100 m...

  16. Paleomagnetic poles from Middle Proterozoic Hazel Formation, Van Horn area, west Texas: Rotations of a Grenville-deformed terrane and correlations with Keweenawan events on craton

    SciTech Connect

    Elston, D.P. ); Clough, G.A. )

    1993-02-01

    An approximately 1,500 m-thick section of moderately to little deformed red beds of the Hazel Formation overlies and caps a more highly deformed sequence of Middle Proterozoic rocks in the Van Horn area, West Texas. As described by P.B. King and associates, accumulation of the Hazel began during an episode of south-to-north thrust faulting that apparently ended deposition of the Allamoore Formation and extended into the time of deposition of the lower Hazel. Three paleomagnetic poles from the middle and upper Hazel form a short apparent polar wandering path plotting in the northern Pacific Ocean and corresponding with no other poles from North America. However, a counterclockwise vertical-axis rotation of 30 [degree] superimposes the Hazel path on a composite north-south-trending polar path from unrotated rocks of the central and western parts of the craton. Following this correction, the Hazel poles correspond with poles from (a) middle and early late Keweenawan rocks of the Lake Superior region, and (b) strata of the upper middle member of Dox Sandstone (Unkar Group), Grand Canyon, Arizona. These rocks accumulated during and immediately following the middle Keweenawan igneous episode and development of the Midcontinent Rift System. The 30[degree] of clockwise offset of the Hazel polar path implies that the Van Horn area was rotated in a clockwise sense following deposition of the Hazel. The opposite senses of rotation between the earlier (severe compressional) and later (more gentle) episodes of folding in the Van Horn region also generally correspond with a looping, hairpin-like reference polar path that first records a counterclockwise and then a clockwise rotation of the craton. The rotations appear explainable as arising from interactions of North America with a plate that initially encroached from the southeast.

  17. Integrated biostratigraphy of foraminifers, radiolarians and conodonts in shallow and deep water Middle Permian (Capitanian) deposits of the "Rader slide", Guadalupe Mountains, West Texas

    USGS Publications Warehouse

    Nestell, M.K.; Nestell, G.P.; Wardlaw, B.R.; Sweatt, M.J.

    2006-01-01

    A diverse assemblage of microfossils is present in a 6m thick sequence of three debris flow deposits interbedded with thin turbidite limestone beds and fine grained siliciclastics exposed above the megaconglomerate in a section (known as the "Rader Slide" in numerous guidebook stops) of the Rader Limestone Member of the Bell Canyon Formation of Capitanian age (Middle Permian) in the Guadalupe Mountains of West Texas. Each debris flow, derived from nearby Capitan Reef shelf-margin and slope deposits, contains a distinct microfossil assemblage. Small foraminifers and fusulinaceans, conodonts, radiolarians, sponge spicules, fish dermal plates and teeth, and other fragmental fossils are present in this sequence. Conodonts are relatively scarce in the first (or lowest) debris flow, except in its upper part, but they are common to abundant in the other two debris flows, and very abundant in several of the thin turbidite limestone beds. All of the conodonts present appear to be morphotypes of one population of the species Jinogondolella postserrata, except for one new conodont species, and the Jinogondolella postserrata Zone is clearly documented in this sequence. The debris flows contain the fusulinaceans Rauserella, rare Codonofusiella, Polydiexodina, Leella? and various species of the small foraminifers Globivalvulina, Hemigordius, Baisalina, Abadehella, Deckerella, Neoendothyranella, Vachardella, Geinitzina, and Polarisella. Some of the thin turbidite limestone beds contain a foraminiferal assemblage similar to that found in the debris flows, but with lower diversity. Many small foraminiferal species appear to be endemic, although a few are closely related to species known in Permian age strata in Italy, Greenland, the Russian Far East, northeastern part of Russia (Omolon massif), and the Zechstein of Germany and the Baltic area. Two thin limestone beds above the second debris flow contain primarily radiolarian species known from the Follicucullus japonicus Zone of

  18. Multibar sawless lint cleaner: fiber quality analysis after 3rd year of field testing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    After two years of field testing a prototype spiked-tooth lint cleaner, the Multibar Sawless Lint Cleaner (MBSLC), a final year of field evaluation was conducted at commercial cotton gin in West Texas located approximately 30 miles Southwest of Lubbock, Texas.The cotton lint cleaner was tested in a ...

  19. Spatial Arrangement of Irrigated Valencia Peanuts to Improve Light Interception and Utilization in - Eastern New Mexico and West Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Planting arrangements can be used to improve resource use efficiency. A field study was conducted on a growers farm South of Clovis, NM in 2006 to compare light interception and radiation use efficiency in a single row, twin row, and diamond planting pattern. The diamond planting pattern places see...

  20. Reactive transport modeling of CO2 injection in the Farnsworth, Texas hydrocarbon field

    NASA Astrophysics Data System (ADS)

    Ahmmed, B.; Appold, M. S.; McPherson, B. J. O. L.; Grigg, R.; White, M. D.

    2014-12-01

    The Farnsworth hydrocarbon field in northern Texas has been an experimental site for CO2 sequestration and enhanced oil recovery for the U.S. Department of Energy-sponsored Southwest Partnership (SWP) since April, 2013. CO2 is to be injected into the Pennsylvanian Morrow Sandstone at a rate of 200,000 tonnes per year for at least five years. The Morrow is a quartz-rich sandstone that lies at a depth of about 2400 m. Pore water in the Morrow has a total dissolved solids content of about 3600 mg/L dominated by Na, Cl, bicarbonate, and Ca. A reactive solute transport model was constructed for a 1700 × 1700 × 95 m volume using the TOUGHREACT software and the ECO2N equation of state for aqueous brine and CO2. Simulations were carried out to 100 years. The results showed immiscible CO2 gas to be concentrated in a lateral plume extending radially from the well screen, its ascent impeded by vigorous lateral groundwater flow in the more permeable upper Morrow. CO2 was much more widespread in aqueous solution, lowering pH throughout much of the model volume after 100 years, to a minimum of about 4.7. The low reactivity of the Morrow Sandstone due to its quartz-rich matrix and dilute pore fluid resulted in little mineral precipitation or dissolution, with net volume changes for any mineral no higher than order 10-4. The simulations predicted net dissolution of albite, calcite, and chlorite, and net precipitation of dawsonite, illite, and magnesite. The Morrow matrix was predicted to undergo slight net dissolution overall, resulting in porosity increases of up to 0.01%, suggesting that the Morrow would be resistant to significant changes in hydraulic properties as a result of the proposed amount of CO2 injection. For the 100 year simulation times calculated thus far, only a small fraction of the injected CO2 would be sequestered as carbonate minerals, with most of the injected CO2 dissolved in the aqueous phase.

  1. Fields of Coal: An analysis of industry and sedimentology in Dolores, Texas

    NASA Astrophysics Data System (ADS)

    Oaden, A.; Besonen, M. R.

    2013-12-01

    Research was conducted on a historically significant pond located in the former mining town of Dolores, located north of Laredo, Texas. The intention of this work was, to determine the influence of local mining operations on the environment and determine the extent of coal production from the sedimentary record. The pond is located ~160 m downslope from a former coal mine and waste pile, and was therefore a likely site of coal accumulations, as well as other debris. Additionally, this pond was created only 130 years ago, in 1882, giving a distinct time frame for any sedimentary records. Field work was conducted to obtain sediment core samples from the pond, and corroborating evidence was gathered using historical documents from archives in Laredo, online resources, as well as library records and inter library loan. Sedimentary cores obtained were shorter than desired as a result of the densely packed clay, which reduceding the penetration of coring equipment, leaving the historical extent of the cores limited. The limited sedimentary record also gives little indication as to the extent of production in the nearby mine and how it may have varied over time. The split cores were scanned with a Minolta CM-2600d spectrophotometer, and the results were transformed into first derivative spectrum equivalent data to identify common sedimentary minerals according to their first derivative signatures. The spectral analysis on the cores determined a large amount of clay minerals, and also limonite/goethite according to prominent first derivative peaks centered on ~440 and 540 nm. This agrees with visual observations given the all minerals showing spectra most intense in the 625 -725 nm portion of the visible spectrum, giving the cores their largely yellowish-reddish/brown hue of the cores. Magnetic susceptibility analysis indicated great changes in mineral contentmagnetism, some possibly associated with ash from fires. Bulk density and loss-on-ignition analysis to further

  2. Exploitation of oil in a volcanic cone by horizontal drilling in the Elaine field, south Texas

    SciTech Connect

    Martinez, P.A.; Kushner, P.L.; Harbaugh, J.W.

    1991-03-01

    The Uvalde volcanic field west and southwest of San Antonio contains many buried volcanic cones that offer attractive places to exploit with horizontal drilling. These buried cones were formed by eruption of basaltic flows and cinders during the Cretaceous when the Austin Chalk and immediately overlying strate were deposited. The cones vary in size, some being as much as 2 mi in diameter and 1000 ft in vertical dimension. During eruptions, flows and ejecta reacted with sea water, producing intermixtures of basaltic material and limestone. These cones provide attractive targets for oil exploration. The Elaine field about 90 mi southwest of San Antonio is associated with a buried volcanic cone that is now being exploited with horizontal drilling. Horizontal Drilling and Production, Inc., ('HDP') drilled the Autumn 1 as the initial horizontal well at Elaine. A vertical hole was drilled through the cone and underlying Austin Chalk, reconfirming the presence of the oil zone at the contact between volcanics and chalk. Moving back up the hole, a cement plug was set within the volcanics, and a horizontal hole was directed on a N 70W azimuth. The inclined hole's vertical angle had progressively decreased with distance to about 30{degree} from the horizontal when the oil zone was reentered. The hole's inclination continued to decrease within the oil zone, becoming horizontal after about 600 ft. With further distance, the hole passed beneath the oil zone, where its inclination was then reversed so that it climbed gradually and reentered the oil zone before reaching its terminal distance of 1500 horizontal feet. The well was completed on August 17, 1990, with an indicated initial production of 1609 BOPD.

  3. Against the Odds: Students, a Teacher, and a School Nurse Build Strong Learning Experiences and a Medical Clinic in West Texas.

    ERIC Educational Resources Information Center

    Active Learner: A Foxfire Journal for Teachers, 1999

    1999-01-01

    In a small rural high school in Balmorhea, Texas, business students helped to establish a school-based clinic. Students wrote grant applications, learned medical office skills, structured the business curriculum around their project, and involved other students. Cooperation with Texas Tech Medical School led to a full-service community clinic…

  4. Bob West and Lopeno Fields: Structure and stratigraphy of two significant Upper Wilcox gas fields in South Texas

    SciTech Connect

    Debus, R.W.

    1996-09-01

    Determining pore size and pore geometry relationships in carbonate rocks and relating both to permeability is difficult using traditional logging methods. This problem is further complicated by the presence of abundant microporosity (pore size less than 62 microns) in the Edwards Limestone. The use of Nuclear Magnetic Resonance Imaging (NMR) allows for an alternative approach to evaluating the pore types present by examining the response of hydrogen nuclei contained within the free fluid pore space. By testing the hypothesis that larger pore types exhibit an NMR signal decay much slower than smaller pore types, an estimate of the pore type present, (i.e.) vuggy, interparticle, or micropores, can be inferred. Calibration of the NMR decay curve to known samples with measured petrophysical properties allows for improved predictability of pore types and permeability. The next stage of the analysis involves the application of the calibration technique to the borehole environment using an NMR logging tool to more accurately predict production performance.

  5. West Clearwater, Quebec impact structure. I - Field geology, structure and bulk chemistry. II - Petrology

    NASA Technical Reports Server (NTRS)

    Simonds, C. H.; Phinney, W. C.; Mcgee, P. E.; Cochran, A.

    1978-01-01

    A field study at the 30-km-diameter West Clearwater impact crater was carried out during the summer of 1977 to identify the nature of the flow of impact melt and less shocked debris during the excavation stage of the cratering process. The present paper investigates: (1) comparisons with other impact craters and lunar samples; (2) generation and emplacement mechanisms of impact melts and associated clastic debris; and (3) the geometry of the transient cavity and the pristine morphology of the crater.

  6. Simulation of the Transport and Dispersion of Perfluorocarbon Tracers Released in Texas Using multiple Assimilated Meteorological Wind Fields

    NASA Astrophysics Data System (ADS)

    Schichtel, B.; Barna, M.; Gebhart, K.; Green, M.

    2002-12-01

    The Big Bend Regional Aerosol and Visibility Observational Study (BRAVO) was designed to determine the causes of visibility impairment at Big Bend National Park, located in southwestern Texas. As part of BRAVO, an intensive field study was conducted during July-October 1999. Among the features of this study was the release of unique perfluorocarbon tracers from four sites within Texas, representative of industrial/urban locations. These tracers were monitored at 21 sites, throughout Texas. Other measurements collected during the field study included upper-level winds using radar profilers, and speciated fine-particulate mass concentrations. MM5 was used to simulate the regional meteorology during BRAVO, and was run in non-hydrostatic mode using a continental-scale 36km domain with nested 12km and 4km domains. MM5 employed observational nudging by incorporating the available measured wind data from the National Weather Service and data from the radar wind profilers. Meteorological data from the National Weather Service's Eta Data Assimilation System (EDAS), archived at 80km grid spacing, were also available. Several models are being used to evaluate airmass transport to Big Bend, including CMAQ, REMSAD, HYSPLIT and the CAPITA Monte Carlo Model. This combination of tracer data, meteorological data and deployment of four models provides a unique opportunity to assess the ability of the model/wind field combinations to properly simulate the regional scale atmospheric transport and dispersion of trace gases over distances of 100 to 800km. This paper will present the tracer simulations from REMSAD using the 36 and 12 km MM5 wind fields, and results from HYSPLIT and the Monte Carlo model driven by the 36km MM5 and 80km EDAS wind fields. Preliminary results from HYSPLIT and the Monte Carlo model driven by the EDAS wind fields shows that these models are able to account for the primary features of tracer concentrations patterns in the Big Bend area. However, at times the

  7. An integrated geological and geophysical study of the Uinta Mountains, Utah, Colorado and a geophysical study on Tamarix in the Rio Grande River basin, West Texas

    NASA Astrophysics Data System (ADS)

    Khatun, Salma

    2008-07-01

    comprehensive picture of the structures in the study area. These models show that the Uinta uplift is a single sedimentary block with numerous thrust faults on the northern and southern flanks of the uplift. These models also reveal the fact that the thickness of the crust is quite variable in the study area. This is also supported by the crustal thickness map constructed for this study from seismic and receiver function information. Magnetic maps show that the Proterozoic sedimentary package known as Uinta Mountain Group extends into the Basin and Range and indicates its link with the ancient rift margin in the Western United States. Findings of this research are correlated to earlier studies and placed in a broader context. Finally an analogy is made between the Uinta aulacogen, the Southern Oklahoma aulacogen and the Dniepr-Donets aulacogen in Ukraine. This discussion focuses light on the mechanism that led to the Uinta's development from a failed rift to an uplift. Part two of this research examined the effect of saltcedar (Tamarix sp) on water and soil properties in the Rio Grande River valley in West Texas. Tamarix is a woody phreatophyte (water-loving plant) common in riparian habitats. The presence of Tamarix in a river system raises concerns about its effect on water quality because it can increase the salinity of water and surrounding soil and it reduces stream flow. Geophysical electrical techniques were used to track soil salinity and moisture changes caused by Tamarix, as well as to determine how soil salinity and moisture properties are altered when Tamarix is eradicated from the region. These techniques allowed more rapid in-situ assessment of the soil properties than the conventional method of removing soil and water samples for analysis. This study was focused on the influence of Tamarix on soil properties and hydrology at the subsurface at four sites in the Rio Bosque Wetlands Park, El Paso, Texas Two sites had flourishing Tamarix and two others were areas

  8. An integrated geological and geophysical study of the Uinta Mountains, Utah, Colorado and a geophysical study on Tamarix in the Rio Grande River basin, West Texas

    NASA Astrophysics Data System (ADS)

    Khatun, Salma

    2008-07-01

    comprehensive picture of the structures in the study area. These models show that the Uinta uplift is a single sedimentary block with numerous thrust faults on the northern and southern flanks of the uplift. These models also reveal the fact that the thickness of the crust is quite variable in the study area. This is also supported by the crustal thickness map constructed for this study from seismic and receiver function information. Magnetic maps show that the Proterozoic sedimentary package known as Uinta Mountain Group extends into the Basin and Range and indicates its link with the ancient rift margin in the Western United States. Findings of this research are correlated to earlier studies and placed in a broader context. Finally an analogy is made between the Uinta aulacogen, the Southern Oklahoma aulacogen and the Dniepr-Donets aulacogen in Ukraine. This discussion focuses light on the mechanism that led to the Uinta's development from a failed rift to an uplift. Part two of this research examined the effect of saltcedar (Tamarix sp) on water and soil properties in the Rio Grande River valley in West Texas. Tamarix is a woody phreatophyte (water-loving plant) common in riparian habitats. The presence of Tamarix in a river system raises concerns about its effect on water quality because it can increase the salinity of water and surrounding soil and it reduces stream flow. Geophysical electrical techniques were used to track soil salinity and moisture changes caused by Tamarix, as well as to determine how soil salinity and moisture properties are altered when Tamarix is eradicated from the region. These techniques allowed more rapid in-situ assessment of the soil properties than the conventional method of removing soil and water samples for analysis. This study was focused on the influence of Tamarix on soil properties and hydrology at the subsurface at four sites in the Rio Bosque Wetlands Park, El Paso, Texas Two sites had flourishing Tamarix and two others were areas

  9. An interdisciplinary approach to reservoir management: The Malu Field, West Niger Delta, Nigeria

    SciTech Connect

    Patterson, B.A.; Bluhm, C.T.; Adokpaye, E.U.

    1995-08-01

    The Malu Field is 175 kilometers southeast of Lagos, offshore Nigeria. The field was discovered in 1967 and brought on stream in 1971. Peak production reached 31,300 barrels per day in 1972. Twenty-six wells have been drilled in the thirty-six square kilometer size field. In 1990 original-oil-in-place was estimated at 345 million barrels with cumulative production of 109 million barrels and an estimated 40 million barrels of remaining reserves. The Main Field review was initiated in 1994 to resolve structural and production inconsistencies and therefore improve reservoir performance. The tools used include reprocessed three-dimensional seismic, oil chemistry (primarily gas chromatography), and production data. The complexly faulted field is subdivided into seven different fault blocks. Growth faults generally trend northwest to southeast and are downthrown to the west. Twenty-five different hydrocarbon-bearing sands have been identified within the field. These sands are separated into sixty-three different reservoirs by the series of southeast trending growth faults. Most sands are laterally continuous within mapped fault blocks except in east Malu. Cross-fault communication of oils occurs among several of the shallow reservoirs in west Malu allowing wells to deplete unintended horizons. In addition, three of the dual string completions are producing oil only from only the upper sands. The integration of seismic, oil chemistry, and production data allows more efficient management of production by providing accurate structure maps, reserve estimates, drainage pathways, and justification for workovers and future development drilling.

  10. Quantifying monthly to decadal subsidence and assessing collapse potential near the Wink sinkholes, west Texas, using airborne lidar, radar interferometry, and microgravity

    NASA Astrophysics Data System (ADS)

    Paine, J. G.; Collins, E.; Yang, D.; Andrews, J. R.; Averett, A.; Caudle, T.; Saylam, K.

    2014-12-01

    We are using airborne lidar and satellite-based radar interferometry (InSAR) to quantify short-term (months to years) and longer-term (decades) subsidence in the area surrounding two large (100- to 200-m diameter) sinkholes that formed above Permian bedded salt in 1980 and 2002 in the Wink area, west Texas. Radar interferograms constructed from synthetic aperture radar data acquired between 2008 and 2011 with the ALOS PALSAR L-band satellite-borne instrument reveal local areas that are subsiding at rates that reach a few cm per month. Subsiding areas identified on radar interferograms enable labor-intensive ground investigations (such as microgravity surveys) to focus on areas where subsidence is occurring and shallow-source mass deficits might exist that could be sites of future subsidence or collapse. Longer-term elevation changes are being quantified by comparing digital elevation models (DEMs) constructed from high-resolution airborne lidar data acquired over a 32-km2 area in 2013 with older, lower-resolution DEMs constructed from data acquired during the NASA- and NGA-sponsored Shuttle Radar Topographic Mission in February 2000 and from USGS aerial photogrammetry-derived topographic data from the 1960s. Total subsidence reaches more than 10 m over 45 years in some areas. Maximum rates of subsidence measured on annual (from InSAR) and decadal (from lidar) time scales are about 0.25 m/yr. In addition to showing the extent and magnitude of subsidence at the 1980 and 2002 sinkholes, comparison of the 2013 lidar-derived DEM with the 1960s photogrammetry-derived DEM revealed other locations that have undergone significant (more than 1 m) elevation change since the 1960s, but show no evidence of recent (2008 to 2011) ground motion from satellite radar interferograms. Regional coverage obtained by radar interferometry and local coverage obtained with airborne lidar show that areas of measurable subsidence are all within a few km of the 1980 and 2002 sinkholes.

  11. Annual Report upon the geographical surveys west of the one-hundredth meridian in the States and Territories of California, Oregon, Nevada, Texas, Arizona, Colorado, Idaho, Montana, New Mexico, Utah, and Wyoming: Being Appendix NN of the Annual Report of the Chief of Engineers for 1877

    USGS Publications Warehouse

    Wheeler, George Montague

    1877-01-01

    I [George M. Wheeler] have the honor to submit the following report for the fiscal year ending June 30, 1877: Including the expeditions of 1876-'77, the fields occupied will have embraced parts of the States and Territories of California, Oregon, Nevada, Texas, Arizona, Colorado, Idaho, Montana, New Mexico, Utah, and Wyoming. The remaining political divisions of the area west of the one-hundredth meridian, into which parties of this expedition have not entered for its survey, are the State of Kansas and the Territories of Washington and Dakota. The work so far has been directed to the most rugged and thinly-settled portions of the western mountain region. As time and means permit, the areas occupied will adjoin the sections of territory already entered and continue toward completion the topographical survey of the entire region.

  12. Notes from the Field: Health Care-Associated Hepatitis A Outbreak - Texas, 2015.

    PubMed

    Wiseman, Rachel; Weil, Lauren M; Lozano, Catalina; Johnson, Thomas J; Jin, Sherry; Moorman, Anne C; Foster, Monique A; Mixson-Hayden, Tonya; Khudyakov, Yury; Kuhar, David T; Graves, Julie

    2016-01-01

    On August 27-28, 2015, the Texas Department of State Health Services received calls from Fort Bend County and Harris County health departments requesting postexposure prophylaxis (PEP) recommendations for contacts of two nurses (patients A and B) with confirmed hepatitis A virus (HAV) infection. Both nurses had symptom onset during August 15-19 and worked for the same pediatric home health care agency in another jurisdiction. Because of the proximity of the onset dates, a common source exposure was suspected. The state and local health departments began an investigation to identify potentially exposed patients, their families, and other agency personnel; offer PEP; and identify the source of exposure. PMID:27123787

  13. Comparison of LANDSAT-2 and field spectrometer reflectance signatures of south Texas rangeland plant communities

    NASA Technical Reports Server (NTRS)

    Richardson, A. J.; Escobar, D. E.; Gausman, H. W.; Everitt, J. H. (Principal Investigator)

    1982-01-01

    The accuracy was assessed for an atmospheric correction method that depends on clear water bodies to infer solar and atmospheric parameters for radiative transfer equations by measuring the reflectance signature of four prominent south Texas rangeland plants with the LANDSAT satellite multispectral scanner (MSS) and a ground based spectroradiometer. The rangeland plant reflectances produced by the two sensors were correlated with no significant deviation of the slope from unity or of the intercept from zero. These results indicated that the atmospheric correction produced LANDSAT MSS estimates of rangeland plant reflectances that are as accurate as the ground based spectroradiometer.

  14. Analysis of Data from a Downhole Oil/Water Separator Field Trial in East Texas

    SciTech Connect

    Veil, John A.; Layne, Arthur Langhus

    2001-04-19

    Downhole oil/water separator (DOWS) technology is available to separate oil from produced water at the bottom of an oil well. Produced water can be injected directly to a disposal formation rather than lifting it to the surface, treating it there, and reinjecting it. Because of a lack of detailed performance data on DOWS systems, the U.S. Department of Energy (DOE) provided funding to secure DOWS performance data. A large U.S. oil and gas operator offered to share its data with Argonne National Laboratory. This report summarizes data from the DOWS installation in eastern Texas.

  15. An Integrated Study of the Grayburg/San Andres Reservoir, Foster and South Cowden Fields, Ector County, Texas

    SciTech Connect

    Robinson, William C.; Trentham, Robert C.; Widner, Kevin; Wienbrandt, Richard

    1999-06-22

    A project to recover economic amounts of oil from a very mature oil field is being conducted by Laguna Petroleum Corporation of Midland, Texas, with partial funding from a U. S. Department of Energy grant to study shallow carbonate rock reservoirs. The objectives of the project are to use modern engineering methods to optimize oil field management and to use geological and geophysical data to recover untapped potential within the petroleum reservoirs. The integration of data and techniques from these disciplines has yielded results greater than those achievable without their cooperation. The cost of successfully accomplishing these goals is to be low enough for even small independent operators to afford. This article is a report describing accomplishments for the fiscal year 1997-1998.

  16. An integrated study of the Grayburg/San Andres reservoir, Foster and South Cowden fields, Ector County, Texas, Class II

    SciTech Connect

    Trentham, DGS, Robert C.; Robinson, M.S., William C.; Wider, Kevin; Weinbrandt, Ph.D.,PE, Richard

    2000-04-14

    A project to recover economic amounts of oil from a very mature oil field is being conducted by Laguna Petroleum Corporation of Midland, Texas, with partial funding from a U. S. Department of Energy (DOE) grant to study shallow carbonate rock reservoirs. The objectives of the project are to use modern engineering methods to optimize oil field management and to use geological and geophysical data to recover untapped potential within the petroleum reservoirs. The integration of data and techniques from these disciplines has yielded results greater than those achievable without their cooperation. The cost of successfully accomplishing these goals is to be low enough for even small independent operators to afford. This article is a report describing accomplishments for the fiscal year 1998-1999.

  17. Field project to obtain pressure core, wireline log, and production test data for evaluation of CO/sub 2/ flooding potential. Texas Pacific Bennett Ranch Unit well No. 310, Wasson (San Andres) Field, Yoakum County, Texas

    SciTech Connect

    Swift, T.E.; Goodrich, J.H.; Kumar, R.M.; McCoy, R.L.; Wilhelm, M.H.; Glascock, M.R.

    1982-01-01

    The coring, logging and testing of Bennett Ranch Unit well No. 310 was a cooperative effort between Texas Pacific, owner of the well, and Gruy Federal, Inc. The requirements of the contract, which are summarized in Enclosure 1, Appendix A, include drilling and coring activities. The pressure-coring and associated logging and testing programs in selected wells are intended to provide data on in-situ oil saturation, porosity and permeability distribution, and other data needed for resource characterization of fields and reservoirs in which CO/sub 2/ injection might have a high probability of success. This report presents detailed information on the first such project. This project demonstrates the usefulness of integrating pressure core, log and production data to realistically evaluate a reservoir for carbon dioxide flood. The engineering of tests and analysis of such experimental data requires original thinking, but the reliability of the results is higher than data derived from conventional tests.

  18. Fluvial architecture and reservoir heterogeneity of middle Frio sandstones, Seeligson field, Jim Wells and Kleberg Counties, south Texas

    SciTech Connect

    Jirik, L.A.; Kerr, D.R.; Zinke, S.G.; Finley, R.J. )

    1990-05-01

    Evaluation of fluvial Frio reservoirs in south Texas reveals a complex architectural style potentially suited to the addition of incremental gas reserves through recognition of untapped compartments or bypassed gas zones. Seeligson field is being studied as part of a GRI/DOE/Texas-sponsored program, in cooperation with Oryx Energy Company and Mobil Exploration and Production U.S., Inc., and is designed to develop technologies and methodologies for increasing gas reserves from conventional reservoirs in mature fields. Seeligson field, discovered in 1937, has produced 2.2 tcf of gas from more than 50 middle Frio reservoirs. Cross sections as well as net sand and log facies maps illustrate depositional style, sandstone geometry, and reservoir heterogeneities. Far-offset vertical seismic profiles show laterally discontinuous reflections corresponding to the reservoirs. Lenticular lateral-bar sandstones dominate channel-fill deposits that together are commonly less than 50 ft thick, forming belts of sandstone approximately 2,500 ft wide. Crevasse-splay deposits commonly extend a few thousand feet beyond the channel system. Sand-rich channel-fill deposits are flanked by levee and overbank mudstones, isolating the reservoirs in narrow, dip-elongate trends. Deposition on an aggrading coastal plain resulted in a pattern of laterally stacked sandstone bodies that are widespread across the study area. Alternating periods of more rapid aggradation resulted in deposition of vertically stacked sandstones with limited areal distribution. Facies architecture of both depositional styles has implications for reservoir compartmentalization. Reservoir compartments within a laterally stacked system may be leaky, resulting from sandstone contact from producing wells along depositional axes. This effect is a major factor controlling incremental recovery. Reservoirs in vertically stacked systems should be better isolated.

  19. Petroleum system analysis of the Hunton Group in West Edmond field, Oklahoma

    USGS Publications Warehouse

    Gaswirth, Stephanie B.; Higley, Debra K.

    2013-01-01

    West Edmond field, located in central Oklahoma, is one of the largest oil accumulations in the Silurian–Devonian Hunton Group in this part of the Anadarko Basin. Production from all stratigraphic units in the field exceeds 170 million barrels of oil (MMBO) and 400 billion cubic feet of gas (BCFG), of which approximately 60 MMBO and 100 BCFG have been produced from the Hunton Group. Oil and gas are stratigraphically trapped to the east against the Nemaha uplift, to the north by a regional wedge-out of Hunton strata, and by intraformational diagenetic traps. Hunton Group reservoirs are the Bois d'Arc and Frisco Limestones, with lesser production from the Chimneyhill subgroup, Haragan Shale, and Henryhouse Formation. Hunton Group cores from three wells that were examined petrographically indicate that complex diagenetic relations influence permeability and reservoir quality. Greatest porosity and permeability are associated with secondary dissolution in packstones and grainstones, forming hydrocarbon reservoirs. The overlying Devonian–Mississippian Woodford Shale is the major petroleum source rock for the Hunton Group in the field, based on one-dimensional and four-dimensional petroleum system models that were calibrated to well temperature and Woodford Shale vitrinite reflectance data. The source rock is marginally mature to mature for oil generation in the area of the West Edmond field, and migration of Woodford oil and gas from deeper parts of the basin also contributed to hydrocarbon accumulation.

  20. The persistence of Black males in the STEM fields at Texas State University

    NASA Astrophysics Data System (ADS)

    Day, Beverly Woodson

    For the past five years, enrollment in the College of Science and Engineering by first-time undergraduate students has steadily increased. However, retaining the students through their first-year and their persistence to their second year of college and beyond has been problematic. The purpose of this study is to add to the knowledge of why Black students, specifically Black men, are not persisting at Texas State University in the STEM majors. It will also determine if specific factors like the SAT scores, parent's education, high school rank, college GPA, college science and math courses (physics, math, biology and chemistry), college credits earned and average GPA in all science and math college courses predict college preparation and college performance for all students and for Black male students.

  1. Texas Field Experiment Results: Performance of the Weatherization Assistance Program in Hot-Climate, Low-Income Homes

    SciTech Connect

    McCold, Lance Neil; Goeltz, Rick; Ternes, Mark P; Berry, Linda G

    2008-04-01

    A field test involving 35 houses was performed in Texas between 2000 and 2003 to study the response of low-income homes in hot climates to weatherization performed as part of the U.S Department of Energy Weatherization Assistance Program and to investigate certain methods to improve weatherization performance. The study found that improved Program designs and the use of advanced energy audits resulted in better weatherization measures being installed (use of blower doors to guide the infiltration work, more frequent installation of attic insulation, and installation of wall insulation) in the study homes, improved space-heating savings performance compared to the Program as implemented in the hot climates in 1989, and more comfortable indoor temperatures. Two key policy dilemmas for Texas and other hot-climate states were highlighted by the study; namely, how to balance expenditures between installing cost-effective weatherization measures and performing health, safety, and repair items, and that health, safety, and repair items can have an adverse impact on energy savings, which further complicates the weatherization decision process. Several occupant and equipment-related behaviors were observed in the field test homes that help explain why audits may over predict energy consumptions and savings and why air-conditioning electricity savings are difficult to measure. Based on this study, it is recommended that states in hot climates be encouraged to select from an expanded list of measures using advanced audits or other techniques, and further studies examining the benefits obtained from air conditioner measures should be performed. In addition, guidelines should be developed for the hot-climate states on how to (a) balance the objectives of saving energy, improving health and safety, and addressing repair issues, and (b) select repair items.

  2. Texas Fires

    Atmospheric Science Data Center

    2014-05-15

    article title:  Wind-Whipped Fires in East Texas     View Larger Image ... western side of the storm stoked fires throughout eastern Texas, which was already suffering from the worst one-year drought on record ...

  3. High resolution reservoir architecture of late Jurassic Haynesville ramp carbonates in the Gladewater field, East Texas Salt Basin

    SciTech Connect

    Goldhammer, R.K.

    1996-12-31

    The East Texas Salt Basin contains numerous gas fields within Upper Jurassic Haynesville ramp-complex reservoirs. A sequenced-keyed, high-resolution zonation scheme was developed for the Haynesville Formation in Gladewater field by integrating core description, well-log, seismic, porosity and permeability data. The Haynesville at Gladewater represents a high-energy ramp system, localized on paleotopographic highs induced by diapirism of Callovian Age Salt (Louann). Ramp crest grainstones serve as reservoirs. We have mapped the distribution of reservoir facies within a hierarchy of upward-shallowing parasequences grouped into low-frequency sequences. The vertical stacking patterns of parasequences and sequences reflect the interplay of eustasy, sediment accumulation patterns, and local subsidence (including salt movement and compaction). In this study we draw on regional relations from analogous, Jurassic systems in Mexico to constrain the stratigraphic architecture, age model, and facies model. Additionally, salt-cored Holocene, grain-rich shoals from the Persian Gulf provide excellent facies analogs. The result is a new high-resolution analysis of reservoir architecture at a parasequence scale that links reservoir facies to depositional facies. The new stratigraphy scheme demonstrates that different geographic portions of the field have markedly distinct reservoir intervals, both in terms of total pay and the sequence-stratigraphic interval within which it occurs. Results from this study are used to evaluate infill drill well potential, in well planning, for updating reservoir models, and in refining field reserve estimates.

  4. High resolution reservoir architecture of late Jurassic Haynesville ramp carbonates in the Gladewater field, East Texas Salt Basin

    SciTech Connect

    Goldhammer, R.K. )

    1996-01-01

    The East Texas Salt Basin contains numerous gas fields within Upper Jurassic Haynesville ramp-complex reservoirs. A sequenced-keyed, high-resolution zonation scheme was developed for the Haynesville Formation in Gladewater field by integrating core description, well-log, seismic, porosity and permeability data. The Haynesville at Gladewater represents a high-energy ramp system, localized on paleotopographic highs induced by diapirism of Callovian Age Salt (Louann). Ramp crest grainstones serve as reservoirs. We have mapped the distribution of reservoir facies within a hierarchy of upward-shallowing parasequences grouped into low-frequency sequences. The vertical stacking patterns of parasequences and sequences reflect the interplay of eustasy, sediment accumulation patterns, and local subsidence (including salt movement and compaction). In this study we draw on regional relations from analogous, Jurassic systems in Mexico to constrain the stratigraphic architecture, age model, and facies model. Additionally, salt-cored Holocene, grain-rich shoals from the Persian Gulf provide excellent facies analogs. The result is a new high-resolution analysis of reservoir architecture at a parasequence scale that links reservoir facies to depositional facies. The new stratigraphy scheme demonstrates that different geographic portions of the field have markedly distinct reservoir intervals, both in terms of total pay and the sequence-stratigraphic interval within which it occurs. Results from this study are used to evaluate infill drill well potential, in well planning, for updating reservoir models, and in refining field reserve estimates.

  5. Structural control is a strategy for exploitation well at Kamojang Geothermal Field, West Java, Indonesia

    SciTech Connect

    Hantono, Djoko; Mulyono, Agus; Hasibuan, Aidil

    1996-01-24

    Kamojang Geothermal Field is one of the best geothermal field in the world, explored since 1918. The field lies 33 km south-east Bandung, West Java. It is located in the centre of a volcanic chain which has progressively grown from WSW to ENE. Three tectonic activities have created current Kamojang structures. Firstly, the circular collapse of Pangkalan, 2 km in diameter whch occupies the central part of the Kamojang field; secondly, NE -SW flults of tensional and lateral origin, are parallel to the magmatic axis; and last, 5 km wide graben is a major expression of NW-SE tensional faults. The faults, having N60 strike in the southeastern part of the field have been identified as a very important structures related to the main target of reservoir Kamojang field. Even if the faults and fractures have been altered in the upper part of the surface and form non permeable seals, the bottom sections may still be highly permeable. Therefore for development drilling one must consider the deep structures instead of just shallow expressions and alteration. Geological correlations between the several wells drilled up to date shows evidence that the structures correspond to the surface features as described above. Case study of well Kamojang denote that the structure identified as Citepus fault is founded in the depth of about 1400 m to 1700 m. v. d

  6. Structural control is a strategy for exploitation well at Kamojang Geothermal Field, West Java, Indonesia

    SciTech Connect

    Hantono, D.; Mulyono, A.; Hasibuan, A.

    1996-12-31

    Kamojang Geothermal Field is one of the best geothermal field in the world, explored since 1918. The field lies 33 km south-east Bandung, West Java. It is located in the center of a volcanic chain which has progressively grown from WSW to ENE. Three tectonic activities have created current Kamojang structures. Firstly, the circular collapse of Pangkalan, 2 km in diameter which occupies the central part of the Kamojang field; secondly, NE-SW flults of tensional and lateral origin, are parallel to the magmatic axis; and last, 5 km wide graben is a major expression of NW-SE tensional faults. The faults, having N60 strike in the southeastern part of the field have been identified as a very important structures related to the main target of reservoir Kamoiang field. Even if the faults and fractures have been altered in the upper part of the surface and form non permeable seals, the bottom sections may still be highly permeable. Therefore for development drilling one must consider the deep structures instead of just shallow expressions and alteration. Geological correlations between the several wells drilled up to date shows evidence that the structures correspond to the surface features as described above. Case study of well Kamojang denote that the structure identified as Citepus fault is founded in the depth of about 1400 m to 1700 m. v. d.

  7. Mapping ERS-1 wind fields over north west Atlantic using a variational objective analysis

    NASA Technical Reports Server (NTRS)

    Siefridt, L.; Legler, D. M.; Barnier, B.; Obrien, J. J.

    1994-01-01

    A variational method is implemented to produce five day mean gridded ERS-1 analyzed wind fields in the north west Atlantic with the aim of providing for wind forcing of basin scale ocean models. The method consists of minimizing a cost functional, designed to measure misfits to prescribed weighted constraints which express a smoothed behavior and the proximity to input data vectors and curl. The weights are empirically determined by comparison with independent ship and buoy data over four five day periods. Root mean square differences between analyzed winds and independent data are thus further decreased: they range from 0.8 up to 1.8 m/s. Some problems present in the initial data remain; they are principally due to incomplete data coverage (instrumental problems), and possibly unresolved ambiguities. The resulting curl fields are smoothed and show coherent patterns. A comparison with the European Center for Medium range Weather Forecasting (ECMWF) analysis is encouraging.

  8. Directional changes of the geomagnetic field in West Africa: Insights from the metallurgical site of Korsimoro

    NASA Astrophysics Data System (ADS)

    Donadini, Fabio; Serneels, Vincent; Kapper, Lisa; El Kateb, Akram

    2015-11-01

    This work shows the first archeomagnetic directions from Western Africa measured on 32 iron smelting kilns dated between 650 and 1800 AD. The archeological excavation of the vast metallurgical site of Korsimoro established the existence of four distinct iron-smelting techniques. The time-frame of each technique could be clearly determined with radiocarbon dating. Many of the kilns investigated in this study could also be dated individually with residual charcoals found in their inside. The results indicate that the inclination of the field changed gradually from shallow normal to shallow reversed during 800 to 1300 AD, and then went back to shallow normal around 1600-1700 AD. The declination was instead stable around 10°E between 800 and 1400 AD, thereafter it started changing towards North. This trend correlates well with available secular variation curves from the Balkan and from Spain, and indicates that the field variation in West Africa was similar to the one in Europe.

  9. Slope stability analysis of landslide in Wayang Windu Geothermal Field, Pangalengan, West Java Province, Indonesia

    NASA Astrophysics Data System (ADS)

    Yuhendar, A. H.; Wusqa, U.; Kartiko, R. D.; Raya, N. R.; Misbahudin

    2016-05-01

    Large-scale landslide occurred in Margamukti village, Pangalengan, Bandung Regency, West Java Province, Indonesia. The landslide damaged geothermal gas pipeline along 300 m in Wayang Windu Geothermal Field. Based on field observation, landslide occured in rotational sliding movement. Laboratory analysis were conducted to obtain the characteristics of the soil. Based on the condition of the landslide in this area, the Factor of Safety can be simulated by the soil mechanics approach. Factor of safety analysis based on soil cohesion and internal friction angle was conducted using manual sensitivity analysis for back analysis. The analysis resulted soil cohesion in critical condition (FS<1) is 6.01 kPa. This value is smaller than cohesion of undisturbed slope soil sample. Water from rainfall is the most important instability factors in research area. Because it decreases cohesion in soils and increases weight and pore water pressure in granular media.

  10. Corpus Christi, Texas

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This near vertical view of the south Texas coast shows the city of Corpus Christi (28.0N, 97.0W) and Corpus Christi Bay. Mustang Island and the Gulf of Mexico are seen in the Southeast corner of the view. The Nueces River flows into the bay from the west. The light toned squiggly lines in Corpus Christi Bay are mud trails caused by shrimp boats dragging their nets along the shallow bottom of the bay.