Download or read book Chemostratigraphy of the Eagle Ford Formation South Texas written by Christopher R. Murley and published by . This book was released on 2014 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Chemostratigraphy of the Eagle Ford Formation written by Timothy J. Kearns and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Late Cretaceous Eagle Ford Formation contains the Cenomanian-Turonian Boundary (CTB). It crops out along the Red River and extends southward through the Dallas-Fort Worth Area of Texas, Waco, Austin and west towards Del Rio and Big Bend. The outcrops were not sampled. Sampling was conducted on cores located at the Bureau of Economic Geology (BEG). The cores were collected from Zavala, La Salle, Frio, Gonzalez, De Witt, and Bee Counties. The Austin Chalk Formation is located above the Eagle Ford Formation and the Buda Formation is located below it. Deposition of the Eagle Ford Formation occurred in the southern portion of Western Interior Seaway (WIS) of North America during a period of high temperature due to greenhouse warming stemming from enhanced volcanism and associated CO2 input. Increased CO2 input ultimately resulted in enhanced continental solubility or weathering and enhanced primary productivity, which resulted in stagnant, oxygen, depleted waters. The effect of the former was to possibly cause the second (OAE-2) of six global ocean anoxic events that occurred during the Cretaceous Period. A combination of enhanced carbonate precipitation from primary productivity and enhanced preservation caused by ocean anoxia led to the deposition of highly carbonaceous organic-rich mudrock. All the samples were measured using a Bruker XRF handheld device. Select samples were measured for %TIC, %TOC, %N, %S, ð13C and ð15N. The data revealed that sampled population included not only the upper and lower portion of the Eagle Ford Formation, but the overlaying Austin Chalk and underlying Buda Formations. This was primarily determined by the Molybdenum concentration. Molybdenum concentration less than or equal to 5 ppm indicate the presence of oxic to suboxic water column conditions. Molybdenum concentration that is greater than or equal to 5 ppm, but less than 20 ppm indicates anoxic water column conditions. Molybdenum concentration that is equal to or greater than 20 ppm indicates euxinic water column conditions. The Eagle Ford Formation was deposited mostly under anoxic to euxinic conditions. The overlying Austin Chalk Formation and underlying Buda Formation were both deposited under dominantly oxic to suboxic conditions. Analyses of the results indicate upwelling was prevalent during much of the deposition of each core. Upwelling is indicated by the enrichment of Phosphorus and depletion of Manganese. Increased continental weathering and upwelling were the likely primary controlling influences that caused anoxic-euxinc water column conditions. Such conditions facilitated enhanced organic matter preservation during the deposition of the Eagle Ford Formation.

Download or read book Chemostratigraphy of the Late Cretaceous Eagle Ford Group South Texass written by Robert Francis Nikirk and published by . This book was released on 2014 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: Strata of the Eagle Ford Group of South Texas, deposited during the Cenomanian and Turonian of the Late Cretaceous, are largely characterized as mixed siliciclastic and carbonate mudrocks rich in organic carbon. The Eagle Ford Group records deposition within the Maverick Basin, along the Comanche Shelf, at the southern margin of the Western Interior Seaway in present-day South Texas. In recent years, the Eagle Ford has emerged as one of the premiere petroleum plays, as it has been proven to be capable of producing significant volumes of dry gas, wet gas/condensates, and oil. It is believed the Eagle Ford represents deposition during the globally correlative Ocean Anoxic Event #2, characterized by the accumulation and preservation of vast amounts of organic carbon due to the expansion of large deep-water oxygen minimum zones. This study integrates geochemical analyses of six drill cores from Gonzales, Guadalupe, La Salle and Wilson counties of South Texas. These cores were studied to determine bulk geochemistry, redox conditions, and degree of basin restriction and deepwater renewal times in order to provide a detailed assessment of the chemostratigraphy and paleoceanography of the Eagle Ford Group. Each core was scanned at one foot intervals with a handheld X-ray fluorescence (XRF) spectrometer to obtain quantitative measurements of major elements, such as Ca, Al and Si, as well as redox sensitive trace metals, such as V, Zn, Ni and Mo. In addition, some cores were analyzed for total organic carbon (TOC), total inorganic carbon (TIC), and stable isotope ([delta]13C and [delta]18O) signatures of the inorganic, carbonate component. The elevated levels of redox sensitive trace metals of the Lower Eagle Ford, represented here by the Lake Waco and Pepper Shale Formations, reveals deposition during a time of anoxic or euxinic conditions leading to the preservation of large amounts of organic carbon (~5% TOC). The South Bosque Formation, representing the Upper Eagle Ford, displays reduced levels of these trace metals, suggesting a return to a more oxygenated environment prior to the deposition of the overlying, fully oxygenated and heavily bioturbated Austin Chalk. The physical paleoceanography of the Eagle Ford is revealed to be restricted at times and more open at others with lower deep-water renewal times, yet remained mainly within an anoxic or euxinic state. In regard to the inorganic stable isotopic data, the [delta]13C carb values, which other studies have shown to display a positive excursion at the time of OAE2, suggest this event is not preserved within the cores analyzed.

Download or read book Chemostratigraphy of the Late Cretaceous Eagle Ford Group South Texas written by Robert Francis Nikirk and published by . This book was released on 2014 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Lithofacies Biostratigraphy Chemostratigraphy and Stratal Architecture of the Boquillas Formation and Eagle Ford Group written by Kathryn O'Rourke Fry and published by . This book was released on 2015 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt: The late Cretaceous-aged Eagle Ford and Boquillas Formations were deposited on the Texas paleoshelf during a major transgressive sequence wherein organic-rich mudrocks accumulated across the paleoshelf. This study investigates lithofacies; biostratigraphy, chemostratigraphy, and stratal architecture of the Eagle Ford and Boquillas Formations to characterize the depositional environment present during deposition, as well as define and describe the Cenomanian-Turonian (C-T) stage boundary and the Oceanic Anoxic Event II (OAE2). Comprehensive, high-resolution data sets compare geologic and geochemical interpretations of subsurface Eagle Ford Group conventional core from the Maverick Basin and chrono-synchronous Boquillas Formation outcrop strata from Big Bend National Park. Results from core and outcrop show a dynamic depositional environment regularly influenced by bottom-currents, debris-flows, and deposition during anoxic bottom-water conditions. Elemental and biostratigraphic data show that the water-column was stratified - surface-waters experienced high levels of primary productivity while deeper waters were anoxic to euxinic. The Eagle Ford strata are divided into a lower and upper group defined geochemically by the appearance of a titanium-rich chemofaceis correlative to massive argillaceous claystone. This change in deposition has been defined to occur concurrently with the C-T boundary (identified biostratigraphically) and OAE2 (identified chemostratigraphically and isotopically). The OAE2 as documented within both cores shows an 'oxygenated' anoxic event, wherein burrowing and low molybdenum are documented during the positive [delta]13C isotope excursion. Outcrop and core data comparison demonstrate a similar depositional system between Big Bend National Park and Maverick Basin; bottom-currents, debris-flows, and periodic anoxia are all documented within both sections, however, further investigations are needed to correlate the sections.

Download or read book Chemostratigraphy of the Austin Chalk and Upper Eagle Ford Shale South Central TX written by Zain Abdi and published by . This book was released on 2014 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt: A single drill core from La Salle, TX was analyzed for its chemical composition and percent concentration of both major and trace elements in order to understand depositional environments and local tectonic activity of the Balcones Fault Zone. The drill core contained the entirety of the Austin Chalk and the upper portion of the Upper Eagle Ford Shale. Samples were taken from 47 boxes at 3 inch intervals which accumulated in a total of 1,680 samples. Each sample was analyzed using a handheld x-ray fluorescence instrument which provided quantitative analysis of the following elements: Al, Ca, Cr, Cu, Fe, K, Mg, Mn, Mo, Ni, P, S, Si, Ti, and V. Furthermore, x-ray diffraction analysis was conducted at every 7 feet of the Austin Chalk and every 4 feet of the Upper Eagle Ford Shale. Calcium values ranged from 5% to 40% with the former values arising from the Upper Eagle Ford Shale and the latter values coming from the Austin Chalk. Sulfur percent composition ranged from 0%-20% and had similar trends as Magnesium which had values from 0.04% to 4.8%. The Austin Chalk contained great values of pyrite, illite, quartz, calcite, and dolomite. Trace element concentrations suggest that the depositional environment had periods of anoxic or euxinic events. Mineralogical and major elemental geochemistry suggests a carbonate rich Austin Chalk and calcareous Eagle Ford Shale.

Download or read book Chemostratigraphy of the Upper Cretaceous from Central and South Texas with Focus on the Eagle Ford Group written by Brett Huffman and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The fine-grained organic-rich rocks of the Eagle Ford (Cenomanian-Turonian) were deposited during the Upper Cretaceous in the shallow waters of the Western Interior Seaway. Five drill cores recovered from two counties, four from Travis County, Texas and one from Frio County, Texas, have been scanned from between two foot and half foot intervals with a hand-held energy-dispersive x-ray fluorescence (HH-ED-XRF) spectrometer to acquire major (e.g. Ca, Si, Al) and trace (e.g. Mo, V, Ni) element data for quantitative analysis. Additionally, gamma ray logs have been analyzed for two of the cores. Major element geochemistry indicates the Eagle Ford deposited in South Texas is different from the Eagle Ford deposited in Central Texas. South Texas Eagle Ford is much more Ca (carbonate) rich, with a noticeably lower Al (clay) content. South Texas and Central Texas Eagle Ford both have low Si (quartz) content relative to the Al and Ca content, indicating a negligible siliciclastic contribution during deposition. Trace element analysis reveals the redox conditions of the bottom waters during deposition. Mn -- an element which becomes mobile and may be removed from an open system in reducing conditions -- levels are much higher in the Austin Chalk and Buda with notably lower values in the Eagle Ford in both Central Texas and South Texas. Mo, an element which tends to bind with organic matter or sulfides during reducing conditions, is notably higher in the Eagle Ford of both South Texas and Central Texas. The correlation of decreased Mn levels and increased Mo levels suggests that the Eagle Ford was deposited in reducing conditions in an open system capable of removing mobilized Mn. Geochemical analysis of major and trace elements obtained from ED-XRF may be used in the petroleum industry in concert with XRD, electric logs, and standard core analysis to give a more complete picture of the depositional environment, clay type and volume, geophysical rock properties, and areal extent of a potential unconventional shale reservoir for hydrocarbon extraction. XRF data offers insight about the rocks, leading to improved understanding of the depositional environment and chemical makeup. Applying these technologies to the Eagle Ford helps unlock the potential of this significant hydrocarbon source and reservoir.

Download or read book High Resolution Geochemistry of the Cretaceous Eagle Ford Shale Bee County Texas written by Lisa Michelle Moran and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Eagle Ford Formation of Bee County, Texas is a sporadically laminated carbonaceous dark mudrock. The depositional area of the Eagle Ford Formation stretches across the state of Texas in a northeast-southwest trend. Early studies of the Eagle Ford found the deposits to be rich in organic material but could not fully describe the formation due to the lack of outcrop exposure. Recent studies of the Eagle Ford Formation have begun to explore the sub-surface nature of the formation. Geochemical analyses of the J.A. Leppard #1 core from the southwestern portion of the formation was conducted to further constrain the sub-surface geochemical signatures of the Eagle Ford Formation. Major and trace element compositions were all measured using a hand- held X-ray fluorescence spectrometer. Bulk geochemistry, trace metal enrichments, inferred mineralogy and geochemical relationships were used as proxies to define the depositional paleoenvironment and degree of basin restriction. The Eagle Ford Formation was deposited under mostly anoxic/euxinic conditions with intermittent pulses of oxygenation. The basin was mostly restricted, but with significant periods of a more open marine setting. Dark mudstones associated with similar depositional histories have previously been linked to global Cretaceous oceanic anoxic events (OAEs). Earlier studies inferred that the Eagle Ford Formation preserved in the J.A. Leppard #1 core preserved a record of the Cenomanian-Turonian boundary. However, biostratigraphic evidence questions the original timing of sedimentation at the core location. It is now believed that the chemostratigraphic patterns could be related to marine preconditioning episodes of anoxia/euxinia prior to a major OAE.

Download or read book Geochronologic and Chemostratigraphic Record of Cenomanian Turonian Eagle Ford South Texas USA written by Michael Anthony Nieto and published by . This book was released on 2016 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Eagle Ford formation written by Millard Boston Arick and published by . This book was released on 1928 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Principles of Elemental Chemostratigraphy written by Neil Craigie and published by Springer. This book was released on 2018-01-11 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides the reader with a comprehensive understanding of the applications of chemostratigraphy. The first chapter of the book offers an introduction to the technique. This is followed by a chapter detailing sample preparation and analytical techniques. Chapter 3 focuses on the techniques utilised to establish the mineralogical affinities of elements, while the general principles of how to build a chemostratigraphic scheme are covered in Chapter 4. Chapters 5, 6 and 7 provide information on the applications of chemostratigraphy to clastic, carbonate and unconventional reservoirs respectively, and various case studies are presented. Wellsite applications, a discussion and conclusion section form the latter part of the book. The book will appeal to graduate and post graduate students of geology and professionals working in the hydrocarbon sector as a key reference text in chemostratigraphy.

Download or read book Stratigraphic Reservoir Characterization for Petroleum Geologists Geophysicists and Engineers written by Roger M. Slatt and published by Newnes. This book was released on 2013-11-21 with total page 688 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reservoir characterization as a discipline grew out of the recognition that more oil and gas could be extracted from reservoirs if the geology of the reservoir was understood. Prior to that awakening, reservoir development and production were the realm of the petroleum engineer. In fact, geologists of that time would have felt slighted if asked by corporate management to move from an exciting exploration assignment to a more mundane assignment working with an engineer to improve a reservoir’s performance. Slowly, reservoir characterization came into its own as a quantitative, multidisciplinary endeavor requiring a vast array of skills and knowledge sets. Perhaps the biggest attractor to becoming a reservoir geologist was the advent of fast computing, followed by visualization programs and theaters, all of which allow young geoscientists to practice their computing skills in a highly technical work environment. Also, the discipline grew in parallel with the evolution of data integration and the advent of asset teams in the petroleum industry. Finally, reservoir characterization flourished with the quantum improvements that have occurred in geophysical acquisition and processing techniques and that allow geophysicists to image internal reservoir complexities. Practical resource describing different types of sandstone and shale reservoirs Case histories of reservoir studies for easy comparison Applications of standard, new, and emerging technologies

Download or read book Diagenetic Modifications of the Eagle Ford Formation written by Richard McAllister and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Chemostratigraphy of the Mississippian age Barnett Formation Fort Worth Basin Wise County Texas USA written by Chizoba Charity Nsianya and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Mississippian-age Barnett Formation is a shale-gas system dominated by fine grained clay-to silt-size particles deposited in the Fort Worth Basin, a peripheral foreland basin that formed during the late Paleozoic as a result of continental collision between Laurasia and Gondwana. A detailed assessment of the chemostratigraphy and depositional environment of the Barnett Formation in the northern end of Fort Worth Basin, Texas will be studied using a variety of geochemical methods. One drill core located in the south-eastern part of Wise County (Texas, USA) was scanned at high resolution (~ 2 inch interval) using a hand- held X-ray fluorescence (ED-XRF) spectrometer in order to provide a quantitative analysis of its major ( e.g. Si, Ca ,Al) and trace (e.g. MO, U, V) element geochemistry. Furthermore, total organic carbon (TOC), total inorganic carbon (TIC) and total nitrogen (TN) data were collected at one-foot sample spacing. Major element geochemistry (Si/Al) suggests a silica rich mudstone; however relative proportions of % silica (SiO2) and Zircon (Zr) suggest that most of this excess silica in the Barnett Formation is biogenic in origin. Trace element relationships reveal that the Barnett Formation in the northern Fort Worth Basin was deposited under anoxic/euxinic conditions with relatively high total organic carbon concentration ranging from 2.0 to approximately 8 %. The organic matter provenance was determined to be primarily of marine origin. Changes in the stratigraphy using EFFe/Al together with DOPT also confirm that the Barnett Formation (lower interval) contains abundant iron relative to normal gray shale.

Download or read book Depositional Dynamics of the Upper Eagle Ford Upper Cretaceous written by Josie Danielle Brunick and published by . This book was released on 2017 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: The mixed siliciclastic/carbonate late Cretaceous Eagle Ford Formation is commonly divided into the lower Eagle Ford and the upper Eagle Ford. The lower Eagle Ford is arguably the most obvious organic rich interval highlighted with wireline log data; however, the upper Eagle Ford may have just as much potential for hydrocarbon production success as the lower Eagle Ford has had. A better understanding of the upper Eagle Ford will allow a more thorough and educated assessment into its full potential as an unconventional reservoir, and allow its sweet spots for oil or gas to be found and exploited. This study is based on the description and interpretation of four cores of the upper Eagle Ford located within Karnes and Gonzales counties, Texas, thin sections, and key XRF data in an effort to better understand its sediment sources and depositional regime. Seven lithofacies were identified in the upper Eagle Ford are as follows: 1) Bioturbated Wackestone/Packstone; 2) Deformed Wackestone/Packstone; 3) Wavy Laminated Wackestone/Packstone; 4) Massive Mudstone/Wackestone; 5) Coarsely to Finely Laminated Wackestone/Packstone; 6) Massive packstone/grainstone; 7) Volcanic Ash. The highest Total Organic Carbon (TOC) percent relative to each core always occurred within the base of the upper Eagle Ford. In fact, the highest TOC percentage recorded was 4.5% within the base of the upper Eagle Ford in the most distally located core. Thorium to Uranium ratios of the upper Eagle Ford were on average less than 1 indicating that the upper Eagle Ford contains very little terrigenous sourced material. Nickel, copper, vanadium, molybdenum, and uranium concentrations were also analyzed and correlated to relative organic matter influx and Paleoredox levels within the upper Eagle Ford in each core.

Download or read book Facies Characterization and Stratigraphic Architecture of Organic rich Mudrocks Upper Cretaceous Eagle Ford Formation South Texas written by Ryan Lee Harbor and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Eagle Ford is a well-known source rock for both sandstone (Woodbine) and carbonate (Austin and Buda) hydrocarbon reservoirs in East and South Texas. Recent discoveries have demonstrated that source rocks, such as the Eagle Ford, are capable of producing significant volumes of gas and oil. At the same time, variations in well producibility indicate that these rocks, like conventional reservoirs, display considerable geological heterogeneity. Yet, only limited research has been published on the subsurface stratigraphy and character of Eagle Ford facies. Understanding the types, controls, and distribution of these heterogeneities requires in-depth rock-based studies. In order to characterize Eagle Ford facies, 27 cores from 13 counties were investigated for rock textures, fabrics, sedimentary structures, and fossil assemblages. These studies were supported by light and electron microscopy as well as analysis of elemental chemistry and mineralogy. Regional subsurface stratigraphic correlations and facies distributions were defined using wireline logs calibrated from core studies. In South Texas, the Eagle Ford Formation was deposited during a second-order transgressive/regressive cycle on the flooded, oxygen-restricted Comanche Shelf. Nine depositional facies consisting predominately of organic-rich, fine-grained (5.0 % TOC) to coarser-grained (3.05 % TOC) fabrics were identified. Facies developed in low-energy environments episodically interrupted by higher-energy, event sedimentation (current winnowing, cohesive and non-cohesive density flows, and turbidity flows). Locally, these rocks show evidence of early diagenetic recrystallization of calcite. Concurrent water anoxia and organic matter preservation persisted locally into later Austin deposition, resulting in formation of a three-fold division of the Cenomanian-Coniacian Eagle Ford Formation. Common facies of lower and upper Eagle Ford members include (1) unlaminated, fissile, clay- and silica-rich, organic-rich mudrocks, (2) laminated, calcareous, organic-rich mudrocks, and (3) laminated, foraminifera- and peloid-rich, organic-rich packstones. The transitional Eagle Ford member consists of highly-cyclic (1) ripple-laminated, organic-rich wackestone (cycle base) and (2) burrowed, organic-lean lime wackestones (cycle top). Transitional Eagle Ford facies developed in oxygen-restricted, basinal depositional environments as distal equivalents to burrowed, foraminiferal lime wackestones of the Austin Formation. Facies complexities in the Eagle Ford stem from complicated and interrelated processes of sediment production and distribution, diagenesis, and water column chemistry. Integrated core studies shed light on both controls of facies formation and their spatial distribution. These findings provide a framework for upscaling the fine-scale, heterogeneous character of shelfal Eagle Ford mudrocks; thus allowing development of predictive models into the distribution of key reservoir properties in the subsurface.

Download or read book Geochemistry and High resolution Chemostratigraphy of the Haynesville Formation East Texas written by Rita Bitar Nehme and published by . This book was released on 2015 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Upper Jurassic Haynesville Formation of East Texas and Louisiana is an organic-rich calcareous mudrock that is Kimmeridgian in age. It underlies the less calcareous Bossier Shale, and it overlies the Smackover Formation limestone. The Haynesville has low permeability, but a relative high porosity, compared to other mudrock formations. Mudrocks are the most common sedimentary rock and some of the most challenging to study, analyze and understand. Despite having a homogeneous appearance on a macroscopic scale, mudrocks often have high variability in facies and composition on the microscopic scale and elemental level. Many studies and methods have been developed to identify facies and stratigraphic variations in mudrocks. A complete understanding of these variations is valuable to comprehend paleoenvironments, paleoclimate and paleoceanographic conditions. Mudrocks studies are also beneficial to shale exploration because these formations, which have a high hydrocarbon content, can be targeted by oil and gas companies for exploration and production. Geochemical methods, chemostratigraphy in particular, will be used in this thesis to complement core description, petrophysical studies and sedimentological studies. This thesis focuses on acquiring chemostratigraphic data from X-Ray Fluorescence (XRF) and X-Ray Diffraction (XRD) measurements to identify elemental and mineralogical variations in the T. W. George core, from the Haynesville Formation in Harrison County, Texas. The data are linked to core description and are analyzed using Hierarchical Cluster Analysis (HCA) to acquire a better understanding of the paleoceanographic conditions and depositional environments that controlled the sediment deposition of the Haynesville Formation. The Haynesville Formation comprises a Ca-rich lower Haynesville, a more Ca-rich upper Haynesville, and underlies the Si-rich and Ca-poor Bossier. The dominant condition during deposition is anoxic/euxinic in the lower Haynesville becoming dysoxic in the upper Haynesville and more oxygenated in the Bossier Formation. The greenhouse climate of the Late Jurassic led to the deposition of strata yielding petroleum source rocks such as the Haynesville Formation that today have great economic value. Thus, studying the Haynesville has both academic and economic importance.