Browsing by Subject "Permian"
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Item Airborne lidar-aided comparative facies architecture of Yates Formation (Permian) middle to outer shelf depositional systems, McKittrick Canyon, Guadalupe Mountains, New Mexico and west Texas(2010-12) Sadler, Cari Elizabeth; Kerans, C. (Charles), 1954-; Steel, Ronald; Fisher, WilliamThe eastern side of the Guadalupe Mountains, located in New Mexico and west Texas, represents an erosional profile along the Capitan reef margin. A complete shelf-to-basin exposure of the Upper Permian Capitan shelf margin is found on the north wall of North McKittrick Canyon, which is nearly perpendicular to the Capitan reef margin. An excellent 2-D sequence stratigraphic framework for upper Permian backreef facies has been developed by previous workers for North McKittrick Canyon (Tinker, 1998) and Slaughter Canyon (Osleger, 1998), forming the basis for observations in this study. The goal of this study is to describe the sequence stratigraphic architecture of the Yates Formation, focusing on the Y4-Y6 high-frequency sequences (HFSs) found in the middle to outer shelf depositional systems, and to illustrate the use of airborne lidar data to quantitatively map at the cycle-scale. Seven measured sections were taken in North McKittrick Canyon. From airborne lidar, 3-D geometries of key sedimentary and structural features were mapped in Polyworks, in addition to the sequence boundaries delineating the Yates 4-6 HFSs. In general, major cycles exhibit asymmetry and shoal upward. Cycle boundaries are sometimes hard to delineate due to amalgamation, particularly in the shelf crest. High-frequency sequences are commonly asymmetric; they deepen and thicken upward toward the maximum flooding surface, and the boundaries between HFSs are usually marked by thick siltstones. Major HFS boundaries can be mapped across the entire dataset, and some component cycles can be observed for minimum distances of one kilometer in an updip-downdip direction. Also, some facies tract dimensions can be estimated directly from the lidar data. Measured sections indicate that the shelf crest facies tract shifts seaward with each successive HFS, while the outer shelf facies tract steps landward. Future work that could be done with the Y4-Y6 HFSs includes 8-10 more measured sections, collection of samples for thin sections, and tracing out of contacts between facies tracts. Extensive lidar data interpretation needs to be done so that digital outcrop models demonstrating facies distributions can be produced. This would enable the development of an outcrop analog model to mixed carbonate-siliciclastic reservoirs, which would be unprecedented in this area.Item Analysis of Areal Permeability Variations - San Andres Formation (Guadalupian): Algerita Escarpment, Otero County, New Mexico(1988-08) Kittridge, Mark Gerard; Lake, Larry W.This paper presents the results of an integrated outcrop and subsurface characterization study conducted on the San Andres Formation of the Permian basin. More than 1600 permeability measurements were obtained from an outcrop section located along the Algerita Escarpment in southeastern New Mexico using an experimental mechanical field permeameter (MFP). Subsurface core data (permeability and porosity) were available from ten closely spaced wells in the Wasson field on the adjacent Northwest Shelf of the Permian basin. Standard population statistics, contour plots and vertical profiles, and geostatistical techniques were used in an attempt to characterize the extremely heterogeneous formation. The outcrop permeability data were found to be log-normally to power-normally distributed, with 12 of 16 data sets having a negative p value. Mean permeability and variance was lowest in the fusulinid dolowackestones, while the highest mean was found in the dolopackstones and dolograinstone intervals. Permeability contour maps of the outcrop grid data typically revealed isolated 'pods' of high permeability in a generally low permeability matrix. The vertical transect measured displayed rapidly varying permeability, with values changing over a very short interval. Geostatistical analysis with the variogram predicted three distinct correlation lengths: 40 feet, 3 to 5 feet, and approximtely 0.25 feet, depending on the spacing of the data used. Predicted correlation length decreased with a decrease in sample spacing. The correlation length was found to be invariant with respect to direction, indicating that the formation is isotropic. Subsurface permeability and porosity data were analyzed in a similar manner. The permeability data was found to be log-normally distributed while the porosity data was power normal. The associated variance on the core plug data was much larger than on the whole core data. Vertical permeability and porosity profiles were similar to that observed from the outcrop vertical transect: alternating high and low values occurring over a very short distance. Variograms indicated a correlation length of approximtely 10.0 feet (vertically) for both permeability and porosity.Item Contributions to the Knowledge of Richthofenia in the Permian of West Texas(University of Texas at Austin, 1916-10-01) Böse, EmilItem Contributions to the Knowledge of Richthofenia in the Permian of West Texas(University of Texas at Austin, 1916-10-01) Böse, EmilItem Controls on mixed carbonate-siliciclastic slope and basinal depositional architecture(2022-05-10) Price, Buddy James; Janson, Xavier; Kerans, C. (Charles), 1954-; Mohrig, David; Covault, Jacob; Eberli, Gregor PDeepwater carbonate depositional systems represent historically understudied environments. The Permian Basin provides an advantageous location to re-evaluate these settings due to subsurface data density as well as existing outcrop and subsurface studies providing a framework on which to expand. Regional well log mapping coupled with cores and seismic data highlight a range of carbonate accumulations along the slopes and in the deeper basin indicating a need for updates to current Permian Basin basinal depositional models. Thickness maps and cross sections highlight multiple mounded and elongate carbonate-mud rich accumulations along the western slopes of the Delaware Basin. The mounded nature, lack of platform focused sourcing, and presence of oblique cross-cutting channels suggest these features represent carbonate contourite drifts as opposed to gravity-driven deposits. The drifts extend from the slopes at specific locations corresponding to bathymetric irregularities that likely locally weakened currents, causing deposition. Drift accumulations significantly alter slope geometries but present only one control on slope variation. Additionally, underlying carbonate buildups generates antecedent topography and drives differential compaction which influences platform to basin relief, subsequent slope gradients, and progradation-aggradation ratios. Bottom currents may also locally sweep sediments from toe-of-slope environments, inhibiting progradation. In the deeper basin, mapping highlights previously undocumented calciclastic submarine fans. The fans appear to be point sourced from the platform by antecedent topography, slope reentrants, and regional faults. Some fans extend into the basin over 100km and reach 250m in thickness. The fans range in composition, containing both carbonate debrites and turbidites, and varying volumes of mud-rich siliciclastic turbidites. Runout of gravity flows resulted in concentration of comparatively coarser carbonate material in proximal fan environments and finer siliciclastic mudstone, siltstone, and organic matter in fan fringe environments. This work highlights the first recognition of a carbonate drift system and the expanded interpretation of large-scale calciclastic submarine fans in the Permian Basin. As the Permian Basin represents one of the most heavily studied and geologic data-rich areas in the world, new interpretations of carbonate drift systems and calciclastic submarine fans indicate these systems are likely more common and overlooked in the ancient rock record.Item A Dasyleptid from the Permian of Kansas, Lepidodasypus Sharovi N. Gen., N. SP. (Insecta: Thysanura: Monura)(Texas Memorial Museum, The University of Texas at Austin, 1975-05) Durden, Christopher J.Lepidodasypus sharovi n. gen., n. sp. is distinguished from previously described species of Dasyleptus by the fine vestiture of scales and hairs, by the heavier pigmentation of the tergites, and by the shorter first maxillary palpi. Preservation of the unique type specimen shows well the presence of segmented abdominal legs, and their posterior specialization to form an ovipositor of ovigerous legs. This is the first record of a dasyleptid monuran from North America and is the oldest representative of the order Thysanura on this continent.Item Depositional architecture and geochemical evolution in Permian Capitan platforms of the Delaware Basin, Texas and New Mexico(2019-09-26) Smith, Benjamin Paul; Kerans, C. (Charles), 1954-; Tinker, Scott W.; Martindale, Rowan C.; Larson, Toti; Zahm, Christopher KentGeochemical data from carbonate sediments are used to constrain chemical changes in ancient oceans. Marine carbonates can be representative of the global ocean, but many ancient carbonates precipitated in isolated water masses such as restricted basins and interior seaways. As a result, geochemical and paleontological records from isolated basins may reflect both global environmental forcing and local water mass evolution. Understanding the interaction between global and local palaeoceanographic change is a key step in unravelling enigmatic marine biotic crises such as the Mid-Capitanian extinction. This study examines factors controlling salinity, stratification, and oxygenation in the Capitanian (Middle Permian) Delaware Basin, USA. Elemental and carbon isotope measurements from time-equivalent strata reveal differences between shallow- and deep- water masses, pointing to local controls such as stratification and de-oxygenated bottom water. Basinal dolomites and evaporites mark periods of elevated salinity commonly tied to sea-level lowstands, which correlate with turnover in fusulinid and brachiopod communities. Faunal turnover in the Delaware Basin demonstrates a fundamental attribute of restricted basin settings: water chemistry is often tightly coupled to physical process such as sea level change. We suggest that the relationships among sea level change, chemical changes, and biotic turnover may explain why the Capitanian mass extinction was more severe in isolated basins than the open ocean.Item The geology of Texas : upper Paleozoic ammonites and fusulinids(University of Texas at Austin, 1937-01-01) Sellards, E.H.Item Hydraulic fracturing sand resource development in the Llano uplift region, central Texas : resource calculation, favorability analysis, and transportation economics(2016-05) Verma, Rahul; Elliott, Brent Alan; Kyle, James Richard; Gutierrez, GenaroUse of naturally occurring sand, one of the most commonly used proppants for hydraulic fracturing, has grown tremendously as a commodity in the past decade as hydraulically wells for petroleum production from unconventional reservoirs increased significantly. USGS estimates that the United States produced more than 94 million metric tons of industrial sand in 2015, almost 52 percent of the global production. About 71 percent the total industrial sand was used for hydraulic fracturing and well packing in 2015. With the recent decline in oil and gas price and exploration drilling, it becomes all the more relevant to develop low cost, locally extracted sand for hydraulic fracturing. The Hickory sandstone unit of the Riley formation in central Texas is one such resource. The region is already one of the largest sand producers in the US and is conveniently located within 200–300 miles of major shale basins in Texas. Barnes and Schofield (1964), and Kyle and McBride (2014) present geological studies of the region and its potential for hydraulic fracturing sand. This study builds on this experience, to calculate for the first time, the total resource volume in the region. Benson et al. (2015) considers high friability, near surface access and proximity to transportation facilities as the three most important qualities of sand resource. As the sand in the Llano uplift region was never buried more than 1,500 feet, it remains friable (Kyle and McBride, 2014). This study estimates the sand resource in the Llano Uplift region to be more than 24 billion metric tons, of which, 20 billion metric tons is characterized by near surface access and proximity to transportation facilities. Several favorable sites for extraction are identified in Mason County, McCulloch County, San Saba County, Barnet County, and Llano County. Several hydraulic fracturing sites in the Barnett, Eagle Ford, and Permian basin, with fracture closure stress less than 6,000 psi, are identified as potential markets for the sand extracted in the Llano Uplift. A transportation cost optimization between using railways and highways, to transport sand from favorable extraction sites to hydraulic fracturing sites, finds that using highways is most cost effective means for transporting to all the sites in the Permian basin, most sites in the Barnett basin, and a few in the Eagle Ford basin. A combination of railways and highways is found to be more cost effective on a few routes to the Barnett and Eagle Ford basin.Item Hydrology of an Evaporite Aquitard Permian Evaporite(1984) Kreitler, Charles W.; Fisher, R. Stephen; Senger, Rainer K.Permian evaporite strata of the Palo Duro Basin, Texas Panhandle, are considered to have low permeabilities but are capable of some leakage. Cross-sectional and areal modeling of regional groundwater flow in the Palo Duro Basin indicates leakage from the Upper aquifer through the Evaporite aquitard that contributes approximately 30 percent of the water in the underlying Deep-Basin Brine aquifer. The regional estimate of permeability of the aquitard (Ëœ 10^-4 md) is in general agreement with laboratory testing of salt permeability. Oxygen and hydrogen isotopic composition and the Cl/Br ratio of the deep-basin brines also suggest leakage through the aquitard. Isotopically nonequilibrated meteoric waters are found to depths of 8,000 ft. Leakage through the aquitard may occur as either matrix or fracture flow. According to petrographic and geochemical studies of the evaporite strata, halite dissolution and minor recrystallization occurred predominantly during Permian time. Post-Permian waters may have altered the top of the Evaporite aquitard. Fracturing is prevalent in the rock strata in the basin; the greatest density of fracturing occurs in areas with tectonic deformation. The potential for leakage may be greatest in these areas.Item Integrated stratigraphic and petrophysical analysis of the Wolfcamp at Delaware Basin, West Texas, USA(2022-04-12) Ramiro-Ramirez, Sebastian; Flemings, Peter Barry, 1960-; Bhandari, Athma R; Daigle, Hugh C; Kerans, Charles; Tisato, NicolaHydrocarbons stored in low-permeability reservoirs, also known as ‘unconventional reservoirs’, represent important energy resources worldwide. Although current technology allows their production at economic rates, there still are numerous production challenges and unknowns regarding their flow behavior. A better understanding on how fluids stored in these reservoirs are drained by the hydraulic fractures after stimulation may help to optimize completion designs and field development plans. This research is an attempt to describe such drainage behavior in the largest oil producing unconventional formation in the World. I investigated the drainage behavior in Wolfcamp reservoirs at the completion scale by integrating stratigraphic and petrophysical analyses with flow modeling. I interpreted the depositional and diagenetic processes that generated three Wolfcamp cores recovered in the central-eastern Delaware Basin, measured the porosity and permeability of distinct lithofacies, and developed simple models to describe flow in these strata. I found that most fluids (~95% of the pore volume) are stored in low-permeability (e.g., < 60 nD) mudstones that I interpreted as hemipelagics and siliciclastics turbidites. Interbedded with these deposits are the low-porosity (~5% of the pore volume) and low-permeability (e.g., < 50 nD) carbonate lithofacies that I interpreted as gravity flow deposits and diagenetic dolomudstones. The carbonate gravity flow deposits, when dolomitized, are up to 2000 times more permeable than the other deposits and represent preferential flow pathways that drain fluids from the low-permeability strata during production. This drainage behavior increases the reservoir upscaled permeability, and therefore production rates, multiple times higher compared to a reservoir consisting of only low-permeability strata. Hence, the presence of these permeable, dolomitized, gravity flow deposits plays a critical role when producing from Wolfcamp reservoirs as they accelerate drainage. These findings are also applicable to other low-permeability formations exhibiting significant permeability heterogeneityItem Letter to A.H. Kemp from H.B. Stenzel on 1963-01-02(1963-01-02) Stenzel, H.B.Item Letter to G.C. Amstutz from H.B. Stenzel on 1963-10-22(1963-10-22) Stenzel, Henryk B.Item Letter to H.B. Stenzel from Augusta H. Kemp on 1962-01-08(1962-01-08) Kemp, Augusta H.Item Letter to H.B. Stenzel from James R. Day on 1933-05-23(1933-05-23) Day, James R.Item Letter to H.B. Stenzel from John Emery Adams on Undated(0000-00-00) Adams, John EmeryItem Letter to H.B. Stenzel from M.K. Elias on 1946-03-07(1946-03-07) Elias, Maxim K.Item Letter to H.B. Stenzel from Robert Cox on 1930-09-24(1930-09-24) Cox, RobertItem Letter to Henryk B. Stenzel from Norman D. Newell on 1965-10-01(1965-10-01) Newell, Norman D.Item Letter to Henryk B. Stenzel from Norman D. Newell on 1966-07-01(1966-07-01) Newell, Norman D.