Coupled accumulation characteristics of Carboniferous-Permian coal measure gases in the Northern Ordos Basin, China
- 55 Downloads
The northern Ordos Basin provides a favorable geological environment for the accumulation and development of coal measure gases (CMG). The hydrocarbon generation potential and reservoir systems of the coal measures have been studied based on data from experimental tests and production and exploration wells, respectively. Further, the coupled accumulation characteristics were determined. The results show that the source rocks are characterized by favorable hydrocarbon generation potential, high thermal evolution (Ro% = 1.3–2.3%), and mainly type III kerogen. Coals, typically aggregated organic matter, with a huge hydrocarbon generation potential (avg. 89.11 mg/g) and total organic content (TOC) (avg. 65.52%), are predominantly involved in gaseous hydrocarbon generation. Shales with good TOC contents (avg. 2.36%) and large cumulative thicknesses have an important role in gaseous hydrocarbon generation. Coal seams, shale layers, and sandstone layers occur as variably interbedded deposits, which form a favorable environment for CMG coupled accumulation. The porosity and permeability are ranked as follows: sandstone > coal > shale, with significant stress sensitivity and anisotropy. Two continuous gas generation peaks occurred in the Late Jurassic and Late Cretaceous, with an abundant amount of coal-derived and thermogenic gas generation, respectively. Potential gas-bearing sandstone layers can be formed by gas migration via short distances from nearby coal seams and shale layers. Coupled accumulation of CMG occurred in three stages: (1) stacked and interbedded reservoirs formation stage; (2) gas generating and charging stage; and (3) coupled accumulation adjustment stage. Coalbed methane (CBM)–tight sandstone gas (TSG) assemblage is a favorable target for CMG accumulation and development.
KeywordsCoal measure gases Hydrocarbon generation potential Reservoir systems Coupled accumulation Coupled accumulation assemblages
This work was jointly sponsored by the Fundamental Research Funds for the Central Universities (No. 2017CXNL03), the National Natural Science Foundation of China (No. 41402124), and the National Science and Technology Major Project (No. 2017ZX05035004-002). The authors also sincerely appreciate the editors and the reviewers for helping to improve the manuscript.
- Ayers WB (2002) Coalbed gas systems, resources, and production and a review of contrasting cases from the San Juan and Powder River basins. AAPG Bull 86(11):1853–1890Google Scholar
- Bian C, Zhao WZ, Wang HJ, Chen ZY, Wang ZC, Liu GD, Zhao CY, Wang YP, Xu ZH, Li YZ, Jiang L (2015) Contribution of moderate overall coal-bearing basin uplift to tight sand gas accumulation: case study of the Xujiahe formation in the Sichuan Basin and the upper Paleozoic in the Ordos Basin, China. Petrol Sci 12(2):218–231CrossRefGoogle Scholar
- Cao DY, Liu K, Liu JC, Qin GH (2016) Combination characteristics of unconventional gas in coal measure in the west margin of Ordos Basin. J China Coal Soc 41(2):277–285Google Scholar
- Chen J, Jia H, Li Y, An C, Li W, Liu S (2016) Origin and source of natural gas in the upper Paleozoic of the Yimeng uplift, Ordos Basin. Oil Gas Geol 37(2):205–209Google Scholar
- Ding W, Zhu D, Cai J, Gong M, Chen F (2013) Analysis of the developmental characteristics and major regulating factors of fractures in marine–continental transitional shale-gas reservoirs: a case study of the carboniferous–Permian strata in the southeastern Ordos Basin, Central China. Mar Pet Geol 45:121–133CrossRefGoogle Scholar
- Law BE (2002) Basin-centered gas systems. AAPG Bull 86(11):1891–1919Google Scholar
- Law BE, Curtis JB (2002) Introduction to unconventional petroleum systems. AAPG Bull 86(11):1851–1852Google Scholar
- Leshchyshyn TT, Rieb BA, Thomson JT (2005) The production success of proppant stimulation on Horseshoe Canyon coal bed methane and sandstone commingled wells. Canadian International Petroleum Conference, 7–9 June, Calgary, Alberta, CanadaGoogle Scholar
- Montgomery SL, Tabet DE, Barker CE (2001) Upper cretaceous Ferron sandstone: major coalbed methane play in Central Utah. AAPG Bull 85(2):199–219Google Scholar
- Peterson R (1984) Geological and production characteristics of the nonmarine part of the Mesaverde group, Rulison field area, Piceance Basin, Colorado. SPE paper 12835, symposium on unconventional gas recovery, Soc petrol Eng, Pittsburgh, Pennsylvania, USA https://doi.org/10.2118/12835-MS.
- Qin Y, Shen J (2016) On the fundamental issues of deep coalbed methane geology. Acta Petrol Sin 37(1):125–136Google Scholar
- Sun ZM, Wang YL, Wei ZF, Zhang MF, Wang G, Wang ZX, Zhuo SG, Xu L (2017) Shale gas content and geochemical characteristics of marine-continental transitional shale: a case from the Shanxi formation of Ordos Basin. J China Univ Min Technol 46(4):859–868Google Scholar
- Tyler R, Kaiser WR, Scott AR, Hamilton DS, Ambrose WA (1994) Geologic and hydrologic assessment of natural gas from coal seams in the Mesaverde group and fort union formation, great Green River basin, Wyoming and Colorado. Topical report for the gas research institute, GRI-93/02320, Bureau of Economic Geology, University of Texas at Austin, Texas, USAGoogle Scholar
- Wang DD, Shao LY, Li ZX, Li MP, Lv DW, Liu HY (2016) Hydrocarbon generation characteristics, reserving performance and preservation conditions of continental coal measure shale gas: a case study of mid-Jurassic shale gas in the Yan’an formation, Ordos Basin. J Pet Sci Eng 145:609–628CrossRefGoogle Scholar
- Xu H, Cao DY, Li Y, Liu JC, Niu XL, Zhang Y, Qin GH (2016) Geochemical and preliminary reservoir characteristics of the carboniferous–Permian coal-bearing strata in the Junger area, northeastern Ordos Basin, China: source implications for unconventional gas. Energy Fuel 30(9):6947–6957CrossRefGoogle Scholar