Geological Characterization of Texas Oil Reservoirs

Of the approximately 153 billion barrels of oil discovered in Texas, conventional techniques and practices are estimated to recover around 33 percent, totaling about 51 billion barrels. If conventional recovery were to reach 40 percent of the original oil in place, which some consider possible, the total conventional production would be around 61 billion barrels. This leaves between 92 and 102 billion barrels of oil as conventionally unrecoverable. Nonconventional recovery methods could potentially target this substantial volume of oil, but the extent to which it can be recovered is a subject of debate among oil professionals. Estimates for nonconventional recovery range from as little as 5 percent to as much as 40 percent. Several factors contribute to this uncertainty, primarily concerning the spatial distribution and geologic occurrence of unrecoverable oil within known reservoirs. Historically, it was assumed that reservoirs and fluid distribution within them were uniform and homogeneous, leading to conventional field development based on a specified number of uniformly spaced wells. However, evidence suggests that many reservoirs exhibit significant geologic variations and compartmentalization, rendering uniform spacing inefficient in tapping and draining the reservoir efficiently. Untapped oil in these areas of geologic complexity is the potential target of strategic infill drilling. Conversely, residual oil remaining in portions of reservoirs that have already been tapped and drained during conventional primary and secondary production is the focus of enhanced or tertiary recovery technologies. These technologies aim to extract additional oil from already depleted reservoirs.Bureau of Economic Geolog

Orbital Maneuvering Vehicle Support To The Space Station

This paper describes the Orbital Maneuvering Vehicle (OMV) and its intended role as a key element of .the National Space Transportation System. Various types of missions, operating modes, and performance capabilities for the OMV are described as are typical mission scenarios, with the OMV based at the Shuttle and at the Space Station (SS). Particular emphasis is placed on OMV missions in support of the SS. Retrieval of a spacecraft to the SS for servicing, followed by redeployment of the spacecraft to its operational orbit is typical of SS-based projected missions

Epigenetic Zonation and Fluid Flow History of Uranium-Bearing Fluvial Aquifer Systems, South Texas Uranium Province

The coastal plain of Texas is becoming increasingly important as a producer of epigenetic sandstone uranium resources. The rapidly expanding database generated by both exploration and mining has, within the past decade, led to the development and refinement of exploration concepts that are, in some respects, unique to the province. Initially, models applied were based on attributes of the well-studied epigenetic uranium deposits of the Wyoming Tertiary basins. The roll-front model and its implicit epigenetic oxidation-reduction zonation proved successful to a point because Gulf Coast deposits do exhibit many features of their Wyoming counterparts. However, deeper exploration and more sophisticated description of known deposits reveal fundamental differences between the depositionally active Gulf Coastal Plain and the interior Tertiary basins. Interior basins have been depositionally inactive since the mid-Tertiary, and the total sediment pile above uranium-bearing aquifers is decreasing as older Tertiary strata continue to erode. In contrast, basinward stratigraphic equivalents of principal Gulf Coast fluvial uranium hosts, such as the Catahoula and Oakville Formations, have been buried deeper than 15,000 ft (4,500 m), and burial has continued throughout the late Tertiary and Quaternary. Additionally, Gulf basin host sands overlie thick sequences of underconsolidated older Tertiary and Mesozoic sediments, which have not yet attained hydrostatic equilibrium with the surface. The result is a hydrologically active basin in which counterflow of geochemically different water masses has existed since the deposition of the host fluvial systems and continues to exist.Bureau of Economic Geolog

Reservoir Characterization of Selected Distal Frio Formation Fields of Texas

Thick, aggradational sequences of shelf and distal shoreface sandstones serve as prolific hydrocarbon reservoirs in the deep, downdip part of the Frio Formation, facing the Greta/Caranchahua shorezone system. Near Corpus Christi, Texas, geopressured shelf reservoirs have yielded more than 190 bcf of gas just in the Corpus Channel and Encinal Channel fields. Within these fields, two thinly bedded shelf-sandstone units (K2 and KS reservoirs) have produced 26 and 38 bcf of gas, respectively. Cross-sections and maps demonstrate that shelf sandstones extend basinward from the distal shoreface toes of barrier-island and beach-ridge sandstone bodies. Shelf sequences typically show upward-coarsening patterns, although upward-fining and heterogeneous sequences are also present. Conventional cores reveal that shelf sequences consist of bioturbated muddy sandstone and sandy mudstone thinly interbedded with planar laminated, sparsely burrowed, and occasionally low-angle cross-laminated or ripple-laminated fine to very fine sandstone. Associated burrow-homogenized siltstone to very fine sandstone sequences range from 1.5 to 6 m (5 to 20 ft) in thickness. Scattered thin zones contain locally derived mudstone clasts, macerated plant fragments, or shell debris. Individual shelf sandstone bodies often exceed 30 m (100 ft) in thickness, particularly when expanded on the downthrown side of major growth faults. In plan view, shelf sandstones form irregular sheets covering areas of several hundreds of square kilometers. Sandstone percentage maps reveal subparallel, discontinuous, strike-oriented buildups lying seaward of the contemporary shoreface sandstone unit. These shore-parallel belts are typically interconnected and attached to the shoreface sand body by one or more dip-oriented channel-like axes.Bureau of Economic Geolog

Catahoula formation of the Texas Coastal Plain : origin, geochemical evolution, and characteristics of uranium deposits

UT Librarie

Description and Interpretation of Test Cores- Brooks and Adjacent Counties, South Texas

This report reviews the results of an examination of approximately 700 feet of core collected during a regional drilling program conducted under the National Uranium Resource Evaluation Program. The location of cored test borings is shown in Figure 1. Core depths ranged from 380 to 2905 feet and included portions of the Catahoula (Oligocene), Oakville/Fleming (Miocene), and Goliad (Pliocene) Formations, all of which are significant uranium hosts in the South Texas Uranium Province. The objectives of the examination included: 1. Description and interpretation of sedimentologic features. 2. Description and interpretation of alteration facies. 3. Mineralogic analysis of selected representative samples. 4. Correlation of drill logs and core intervals within the framework developed in the course of regional stratigraphic studies. 5. Geochemical analysis of selected samples to assess alteration mineralogy and trace metals content.Bureau of Economic Geolog

Predicting Response of An Aquifer System to Uranium Extraction Oakville Aquifer, Texas Coastal Plain

The initiation or expansion of uranium mining in the Texas Gulf Coastal Plain, utilizing both open-pit and in situ leach methods, raises concerns about the potential impact on groundwater within mineralized aquifers. Understanding the hydrodynamics, hydrochemical evolution, and matrix geochemistry of these aquifers is essential for implementing effective protection and restoration measures. To address these issues, the Oakville Sandstone, a significant Coastal Plain aquifer, was chosen as a natural laboratory. The Oakville Sandstone comprises deposits from several major fluvial systems. The geometry and composition of these facies, along with superimposed structures and topography, play crucial roles in determining groundwater flux, aquifer transmissivity, and regional hydrochemical evolution. Groundwater flux patterns, especially in the shallow portions suitable for mining, can be highly complex and influenced by various factors. Studying the interrelationships among hydrodynamics, hydrochemical evolution, and matrix geochemistry in the Oakville Sandstone will provide insights into the effectiveness of mining technology in coastal plain aquifer systems. This research will aid in developing strategies to mitigate potential impacts on groundwater quality and ensure sustainable uranium mining practices in the region.Bureau of Economic Geolog

Sandstone Consolidation Analysis to Delineate Areas of High Quality Reservoirs Suitable for Production of GeoPressured Geothermal Energy Along the Texas Gulf Coast

Analysis of reservoir quality of lower Tertiary sandstones along the Texas Gulf Coast delineatesareas most favorable for geopressured geothermal exploration. Reservoir quality is determined by whole core, acoustic log, and petrographic analyses. Wilcox sandstones exhibit no regional reservoir quality trends. In the Lower and parts of the Middle and Upper Texas Gulf Coast, the sandstones are relatively well consolidated, but in other parts of the Middle and Upper Texas Gulf Coast, they show a reversal toward increased porosity at depth. Vicksburg sandstones have the poorest reservoir quality of sandstones of any formation prospective for geothermal energy. Frio sandstones show a systematic increase in reservoir quality from the Lower to the Upper Texas Gulf Coast. This increase in reservoir quality correlates to changes in rock composition and cementation. Acoustic log analysis substantiates a progression of greater consolidation from the Upper to the Lower Texas Gulf Coast. Wilcox sandstones are poorly to moderately sorted, fine-grained, quartzose lithic arkoses, becoming more quartz-rich from the Upper to the Lower Texas Gulf Coast. Most rock fragments are metamorphic and volcanic. Vicksburg sandstones are poorly sorted, fine-grained lithic arkoses. Rock fragments are mainly volcanic clasts with lesser carbonate and minor metamorphic clasts. Frio sandstones range from poorly sorted, fine-grained, feldspathic litharenites to lithic arkoses in the Lower Texas Gulf Coast to poorly sorted, fine-grained, quartzose lithic arkoses to subarkoses in the Upper Texas Gulf Coast. Volcanic rock fragments predominate in all areas; carbonate rock fragments are common in the Lower Texas Gulf Coast.Bureau of Economic Geolog

Application of fluvial scaling relationships to reconstruct drainage-basin evolution and sediment routing for the Cretaceous and Paleocene of the Gulf of Mexico

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.Fluvial systems represent a key component in source-to-sink analysis of ancient sediment-dispersal systems. Modern river channels and channel-related deposits possess a range of scaling relationships that reflect drainage-basin controls on water and sediment flux. For example, channel-belt sand-body thicknesses scale to bankfull discharge, and represent a reliable first-order proxy for contributing drainage-basin area, a proxy that is more robust if climatic regimes can be independently constrained. A database of morphometrics from Quaternary channel belts provides key modern fluvial system scaling relationships, which are applied to Cretaceous- to Paleocene-age fluvial deposits. This study documents the scales of channel-belt sand bodies within fluvial successions from the northern Gulf of Mexico passive-margin basin fill from well logs, and uses scaling relationships developed from modern systems to reconstruct the scale of associated sediment-routing systems and changes in scale through time. We measured thicknesses of 986 channel-belt sand bodies from 248 well logs so as to estimate the scales of the Cretaceous (Cenomanian) Tuscaloosa-Woodbine, Paleocene–early Eocene Wilcox, and Oligocene Vicksburg-Frio fluvial systems. These data indicate that Cenozoic fluvial systems were significantly larger than their Cenomanian counterparts, which is consistent with Cretaceous to Paleocene continental-scale drainage reorganization that routed water discharge and sediment from much of the continental United States to the Gulf of Mexico. At a more detailed level, Paleocene–early Eocene Wilcox fluvial systems were larger than their Oligocene counterparts, which could reflect decreases in drainage-basin size and/or climatic change within the continental interior toward drier climates with less runoff. Additionally, these data suggest that the paleo–Tennessee River, which now joins the Ohio River in the northernmost Mississippi embayment of the central United States, was an independent fluvial system, flowing southwest to the southern Mississippi embayment, or directly to the Gulf of Mexico, through the early Eocene. Changes in scaling relationships through time, and interpreted changes in the scales of contributing drainage basins, are generally consistent with previously published regional paleogeographic maps, as well as with newly published maps of paleodrainage from detrital-zircon provenance and geochronological studies. As part of a suite of metrics derived from modern systems, scaling relationships make it possible to more fully understand and constrain the scale of ancient source-to-sink systems and their changes through time, or cross-check interpretations made by other means

Association of urinary bisphenol a concentration with heart disease: evidence from NHANES 2003/06.

addresses: Epidemiology and Public Health Group, Peninsula Medical School, University of Exeter, Exeter, United Kingdom. [email protected]: PMCID: PMC2800195types: Journal Article; Research Support, Non-U.S. Gov'tCopyright: © 2010 Melzer et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Bisphenol A (BPA) is a high production volume chemical widely used in food and drinks packaging. Associations have previously been reported between urinary BPA concentrations and heart disease, diabetes and liver enzymes in adult participants of the National Health and Nutrition Examination Survey (NHANES) 2003/04. We aimed to estimate associations between urinary BPA concentrations and health measures in NHANES 2005/06 and in data pooled across collection years