DOI: 10.1306/11221111071
Scopus记录号: 2-s2.0-84865379607
论文题名: Geological and geochemical characterization of the Lower Cretaceous Pearsall Formation, Maverick Basin, south Texas: A future shale gas resource?
作者: Hackley P.C.
刊名: AAPG Bulletin
ISSN: 0149-1749
EISSN: 1558-9479
出版年: 2012
发表日期: 2012
卷: 96, 期: 8 起始页码: 1449
结束页码: 1482
语种: 英语
Scopus关键词: Analytical investigations
; Bioturbation
; Broad size distribution
; Confidence levels
; Depositional environment
; Dry gas
; Engineering challenges
; Fractiles
; Geochemical characterization
; Hydrocarbon assessment
; Hydrocarbon generation
; Hydrocarbon resources
; In-situ
; Inert solids
; Liquid hydrocarbons
; Low permeability
; Lower Cretaceous
; Mesozoic
; Natural gas resources
; Northern Gulf of Mexico
; Organic materials
; Oxic conditions
; Oxygenated environments
; Petrographic analysis
; Petroleum geologists
; Rock-Eval
; Sediment deposition
; Shale gas
; Shelf edges
; Shell fragments
; Solid bitumen
; Spatial extent
; Thermal cracking
; Thermal maturity
; Total Organic Carbon
; Type II
; U.s. geological surveys
; Vitrinite reflectance
; Clay minerals
; Cracking (chemical)
; Crystallography
; Energy resources
; Gases
; Hydrocarbons
; Kerogen
; Lime
; Mineralogy
; Minerals
; Natural gas
; Petroleum deposits
; Quartz
; Reflection
; Size distribution
; Stratigraphy
; Shale
; bioturbation
; Cretaceous
; depositional environment
; facies
; geochemical survey
; hydrocarbon resource
; kerogen
; lithostratigraphy
; natural gas
; permeability
; sampling
; shale
; shelf break
; thermal maturity
; total organic carbon
; Maverick Basin
; Texas
; United States
; Apoidea
Scopus学科分类: Energy
; Earth and Planetary Sciences
英文摘要: As part of an assessment of undiscovered hydrocarbon resources in the northern Gulf of Mexico onshore Mesozoic section, the U.S. Geological Survey (USGS) evaluated the Lower Cretaceous Pearsall Formation of the Maverick Basin, south Texas, as a potential shale gas resource. Wireline logs were used to determine the stratigraphic distribution of the Pearsall Formation and to select available core and cuttings samples for analytical investigation. Samples used for this study spanned updip to downdip environments in the Maverick Basin, including several from the current shale gas-producing area of the Pearsall Formation. The term "shale" does not adequately describe any of the Pearsall samples evaluated for this study, which included argillaceous lime wackestones from more proximal marine depositional environments in Maverick County and argillaceous lime mudstones from the distal Lower Cretaceous shelf edge in western Bee County. Most facies in the Pearsall Formation were deposited in oxygenated environments as evidenced by the presence of biota preserved as shell fragments and the near absence of sediment laminae, which is probably caused by bioturbation. Organic material is poorly preserved and primarily consists of type III kerogen (terrestrial) and type IV kerogen (inert solid bitumen), with a minor contribution from type II kerogen (marine) based on petrographic analysis and pyrolysis. Carbonate dominates the mineralogy followed by clays and quartz. The low abundance and broad size distribution of pyrite are consistent with the presence of oxic conditions during sediment deposition. The Pearsall Formation is in the dry gas window of hydrocarbon generation (mean random vitrinite reflectance values, R o = 1.2-2.2%) and contains moderate levels of total organic carbon (average 0.86 wt. %), which primarily resides in the inert solid bitumen. Solid bitumen is interpreted to result from in-situ thermal cracking of liquid hydrocarbon generated from original type II kerogen that was prevented from expulsion and migration by low permeability. The temperature of maximum pyrolysis output (T max) is a poor predictor of thermal maturity because the pyrolysis (S2) peaks from Rock-Eval analysis are ill defined. Vitrinite reflectance values are consistent with the dry gas window and are the preferred thermal maturity parameter. A Maverick Basin Pearsall shale gas assessment unit was defined using political and geologic boundaries to denote its spatial extent and was evaluated following established USGS hydrocarbon assessment methodology. The assessment estimated a mean undiscovered technically recoverable natural gas resource of 8.8 tcf of gas and 3.4 and 17.8 tcf of gas at the F95 and F5 fractile confidence levels, respectively. Significant engineering challenges will likely need to be met in determining the correct stimulation and completion combination for the successful future development of undiscovered natural gas resources in the Pearsall Formation. Published by the American Association of Petroleum Geologists © 2012 U.S. Geological Survey. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84865379607&doi=10.1306%2f11221111071&partnerID=40&md5=4fdc2ad8e729d880658973256725e2eb
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/13319
Appears in Collections: 过去全球变化的重建 影响、适应和脆弱性 科学计划与规划 气候变化与战略 全球变化的国际研究计划 气候减缓与适应 气候变化事实与影响
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Recommended Citation:
Hackley P.C.. Geological and geochemical characterization of the Lower Cretaceous Pearsall Formation, Maverick Basin, south Texas: A future shale gas resource?[J]. AAPG Bulletin,2012-01-01,96(8)