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 Applications of conodonts in resolving Pennsylvanian-Permian stratigraphic problems in north-central Texas, New Mexico, Colorado, and Kansas(Texas Tech University, 2002-08) Keairns, Carter EwingPennsylvanian-Permian strata of midcontinent North America comprise numerous cyclothems that are the result of repetitive sea-level changes that produced multiple alternations of marine and non marine facies. Placement of chronostratigraphic boundaries within cyclothems is problematic because the variations in sea-level do not allow a continuous representation of marine facies. This creates gaps in the faunal (and floral) record across potential series and stage boundary intervals. Conodont faunas were collected from localities in north-central Texas, Kansas, Oklahoma, and the Sacramento Mountains of New Mexico. These collections were analyzed for biostratigraphically significant faunas that could delineate, with greater resolution, the Late Pennsylvanian Missourian-Virgilian Boundary. Size criteria, in particular the use of adults not juveniles for index species is addressed, determining that indeed size does matter, and that adult forms are the only platforms that should be considered as biostratigraphically significant. Two new morphotypes of Streptognathodus, Streptognathodus sp. C and Streptognathodus sp. D were identified on the basis of carina length and termination relative to platform length. These new morphotypes combined with existing species Streptognathodus firmus, Streptognathodus pawhuskaensis, and Idiognathus simulator, were sufficient to develop diagnostic faunal zones across the boundary interval. Correlations were based on first appearances of three streptognathodid species, and then a second level of confidence obtained with percentages of species in successive faunas. The newly developed zonations was successfully used to correlate the Stanton, South Bend, and Iatan cycles of midcontinent Kansas with the Upper Winchell, Placid- Ranger dual cycle, and Colony Creek of north-central Texas. The new zonation was extended into New Mexico permitting correlation of the Missourian-Virgilian boundary strata (South Bend cycle) near cycle 2C-5a (of Raatz). The majority of Dry Canyon samples were stratigraphically above the boundary, as evidenced by the presence of the conodont I. lohatulus, and two forms of S. virgilicus that resemble the new morphotypes S. sp C and S. sp. D. It appears as though the trend of a shortening carina, that was useful at the Missourian-Virgilian boundary may 'reset' and repeat itself higher in the Virgilian. In Central Colorado, conodont collections from the Kerber and Sharpsdale formations (Morrowan- Atokan) were assessed for possible biostratigraphic correlation to other regions of Colorado. The carbonates of the upper Kerber and lower Sharpsdale are latest Morrowan based on the conodont data. Recommendations are to sample the Central Colorado equivalent, the Belden Shale for additional, and hopefully, diagnostic conodont faunas.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 Outcrop analysis of ooid grainstones in the Permian Grayburg Formation, Shattuck Escarpment, New Mexico(2013-08) Parker, John Alexandre; Kerans, C. (Charles), 1954-Ooid grainstone reservoir architecture remains poorly understood, particularly because of sedimentologic and stratigraphic heterogeneities that are innate to grainstone body development. Understanding of Geospatial relationships and recovery of hydrocarbons from these significant reservoir facies can be improved with access to outcrop analog information from well exposed examples. Object-based models and other modern subsurface reservoir models are considered superior methods for portraying realistic sediment distributions. These models, however, are highly dependent on input data describing sediment-body geometry for faithful template generation. Such input data are notably rare in carbonate systems. Maps generated from modern depositional patterns give a first approximation of areal distribution, but they are not as useful for understanding final preserved stratigraphic thickness and internal facies, sedimentary structure, and grain-type patterns. For this purpose, studies of exceptional outcrops are required. The 18 km long oblique-dip-oriented wall of the Shattuck Escarpment provides such a unique exposure of Permian-age grainstones. The Shattuck Escarpment in the Guadalupe Mountains provides an oblique-dip profile that exposes a near-complete middle Permian Grayburg mixed clastic-carbonate shelf succession of three high-frequency sequences which contain 30 high-frequency cycles. Particularly important for this study are the four cycles that display full updip to downdip extents of ooid grainstone tidal bar and tidal delta objects. The data from the Shattuck wall presented in this paper focusses on the transgressive portion of the upper Grayburg, or G12 high-frequency sequence (HFS), located 5 km landward of the time-equivalent shelf margin. This interval is an analog for productive fields along the northwest shelf of the Delaware Basin and on the eastern flank of the Central Basin Platform. The goal of this project is to understand the sedimentology and facies/cycle architectural variability of tidally influenced shelf crest ooid grainstones of the Grayburg Formation. Comparing this outcrop data to modern grainstone deposits allows the reader to understand the small-scale and large-scale sedimentologic and architectural patterns in analogous subsurface ooid grainstone reservoirs. Spatial analysis of these cycles was carried out using measured sections and GigaPan (high resolution photomosaic) data. Petrophysical (Porosity and Permeability) data was collected from three separate vertical core plug transects approximately 1 km apart with a vertical resolution of 30 cm. Cycle-set-scale grainstone complexes up to 6m thick extend at least 4.25 km along depositional dip and show variations in permeability between 6-400 mD and porosities between 8-20% within the lower portions of the grainstone complex.Item Stratigraphy and reservoir architecture of a Permian toe-of-slope ooid fan, Happy (Spraberry) Field, Garza Co., Texas(2011-05) Clayton, Jason Lars; Kerans, C. (Charles), 1954-; Steel, Ronald; Janson, XavierThe Permian (Leonardian) aged Upper Spraberry Formation found in the Happy Field of Garza Co. TX, contains one of the best examples of a reservoir composed of resedimented carbonates in a deep-water slope-basin setting, with numerous whole core of wells with full suites of electric logs, high resolution 3D seismic coverage, and 20+ years worth of production data. Sequence stratrigraphic analysis from seismic data combined the lithologic analysis from outcrop analog, core, and well log data helps identify that the Happy Field is located within the transgressive systems tract of the fifth composite sequence in the Leonardian. The reservoir is composed of discrete allochthonous ooid and skeletal grains transported downslope via hyperconcentrated density flows sourced from a re-entrant in the shelf margin and deposited in a long-lived topographic depression at the toe-of-slope. Vertical heterogeneity due to layers of shaley silt punctuated by successive flows of oolitic and skeletal grains along with lateral heterogeneity created by younger flows of material create reservoir compartmentalization which can impede efficient development. Core-calibrated electric log correlations aids in the mapping of isolated compartments which helps with efficient development planning for the field.Item Temporal and spatial evolution of the Cave Graben Fault System, Guadalupe Mountains, New Mexico(2014-12) Mathisen, Maren Gabriella; Kerans, C. (Charles), 1954-; Zahm, Christopher KentNumerous recent studies have demonstrated the importance of syndepositional faulting as an inherent element of steep-rimmed carbonate margins. However, these studies have not emphasized the relationship to older shelf margins, multiphase deformation history, and complexity of fault zone internal structure. In the Guadalupe Mountains, New Mexico, extensive syndepositional deformation parallels the Permian Capitan shelf margin reef and has developed in the absence of regional tectonic forces due to a combination of early carbonate cementation, gravitational instability, differential compaction, and variable progradation to aggradation at pre-existing shelf margins. This study focuses on the geometry, growth history, and internal fill type distribution within the Cave Graben Fault System (CGFS) in Slaughter and Rattlesnake Canyons of the Guadalupian (Capitan) shelf margin with the intent to understand the temporal and spatial evolution of deformation in front of the G24 shelf margin. Stratigraphy, faults and fractures exposed within the CGFS were mapped using high-resolution gigapan photos and GPS, along with RCRL Guadalupe airborne lidar, provides a geospatial database for 3D visualization, quantification, and interpretation. Detailed mapping reveals a high degree of variability in fault geometry, including the presence of vertical and lateral fault relays, antithetic and synthetic splays, and highly variable fault and fracture apertures, suggesting a complex deformational history. Hundreds of early-formed fractures have been mapped within the G24-G25 shelf margin system, but the development of significant faults with appreciable displacement only occurs in front of the G24 margin. Vertical fault displacement varies from 9 to 34 m in the CGFS. Breccias several meters in width fill the main faults and contain entrained sediment and clasts of variable age and composition. Stratal geometries reveal that movement and episodic growth occurred along the faults soon after deposition. Further investigation of the sediment and breccia fills suggests that a significant dissolution event along the fault allowed for the entrainment of much younger, post-Permian sediment. Based on these findings it appears that in Rattlesnake Canyon at least 30-60% of the CGFS vertical displacement occurs in the Permian, whereas up to 40-70% may develop post-Permian, providing a significant advancement in the understanding of timing of fault systems within the Capitan shelf margin.