Mathematical Simulation of Coal-generating Hydrocarbons Based on Pyrolysis Products from Coal Macerals under Closed System

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  • 1.Exploration and Production Research Institute, SINOPEC, Beijing 100083, China;
        2.Prospecting and Surveying Institute of Dongying City, Dongying 257091,China

Received date: 2008-09-09

  Revised date: 2009-01-19

  Online published: 2009-02-10

Abstract

Based on the hydrocarbon yields and carbon isotopes of methane from the three end-member macerals (vitrinite, exinite, inertinite) under closed system pyrolysis, isothermal temperature conditions, a mathematic model of oil generation and efficient expulsion from coal as a hydrocarbon-sourcing rock was done when the efficient expulsion of hydrocarbons from coal is experientially assumed to be 30 mg/gTOC.According to the simulated results, the hydrogen enriched maceral is prone to the oil generation, where the relative proportion of exinite component in coal as an active oil source is at least 5.0% whereas vitrinite is at most 95.0%. If the exinite content is more than 22.9% of coal components, the oil is generated and efficiently expelled from coal whatever the contents of two other macerals (vitrinite and inertinite). Meanwhile, the carbon isotope fractionation of methane from the maceral components at thermal stages was matched according to the simulated model. These mathematically calculated observations imply that coals with the different end\|member macerals would generate natural gas with changed δ13CCH4 values, where the maximum δ13CCH4 value  is  2.3‰. Thus, the δ13CCH4 value is constrained by not only thermal maturity of source rock, but also maceral components.

Cite this article

LIU Quan-You, LIU Wen-Hui, WANG Chang-Hua . Mathematical Simulation of Coal-generating Hydrocarbons Based on Pyrolysis Products from Coal Macerals under Closed System[J]. Natural Gas Geoscience, 2009 , 20(1) : 20 -25 . DOI: 10.11764/j.issn.1672-1926.2009.01.20

References

    [1]  王祥,张敏,黄兴辉.典型海相油和典型煤成油轻烃组成特征及地球化学意义[J].天然气地球科学,2008,19(1):18 -22.
 [2] 程克明.吐哈盆地煤成油气的地质地球化学研究[J].勘探家,1997,2(2):5 -10.
 [3] 黄第藩,秦匡宗,王铁冠,等.煤成油的形成和成烃机理[M].北京:石油工业出版社,1995.
 [4] Durand B,Paratte M.Oil potential of coals:A geochemical Approach\[M\]//Petroleum Geochemistry and Exploration of Europe.Oxford:Blackwell Scientific,1983:255 -265.
 [5] Bertrand P,Behar F,Durand B.Composition of potential oil from humic coals in relation to their petrographic nature[J].Organic Geochemistry,1986,10(1 -3):601 -608.
 [6] Boreham C J,Powell T G.Variation in pyrolysate composition of sediments from the Jurassic Walloon coal measures,eastern Australia as a function of thermal maturation[J].Organic Geochemistry,1991,17(6):723 -733.
 [7] Littke R,Leythaeuser D.Migration of oil and gas in coals[J].AAPG Bulletin,2001,38:219 -236.
 [8] Bechtel A,Gruber W,Sachsenhofer R F,et al.Organic geochemical and stable carbon isotopic investigation of coals Formed in low -lying and raised mires within the eastern Alps(Austria)[J].Organic Geochemistry,2001,32(11):1289 -1310.
 [9] Brook J D,Smith J W.The diagenesis of plant lipids during the formation of coal,petroleum and natural gas,Ⅱ:Coalification and formation of oil and gas in the Gippsland Basin[J].Geochimica et Cosmochimica Acta,1969,33:1183 -1194.
[10] Killops S D,Woolhouse A D,Weston R J,et al.A geochemical appraisal of oil generation in the Taranaki Basin,New Zealand[J].AAPG Bulletin,1994,78:1560 -1585.
[11] Peters K E,Snedden J W,Sulaeman A,et al.A new geochemical -sequence stratigraphic model for the Mahakam delta and Makassar slop,Kalimantan Indonesia[J].AAPG Bulletin,1999,83:1332 -1333.
[12] Petersen H I,Rosenberg P,Andsbjerg J.Organic geochemistry in relation to the depositional environments of middle Jurassic coal seams,Danish central graben,and implications for hydrocarbon generative potential[J].AAPG Bulletin,1996,80(1):47 -62.
[13] 戴金星.加强天然气地学研究[KG*2]勘探更多大气田[J].天然气地球科学,2003,14(1):3 -14.
[14] Liu Q,Liu W,Dai J.Characterization of pyrolysates from maceral Components of Tarim coals in closed system experiments and implications to natural gas generation[J].Organic Geochemistry,2007,38(6):921 -934.
[15] 刘全有,刘文汇,孟仟祥.塔里木盆地煤岩在不同介质条件下热模拟实验中烷烃系列有机地球化学特征[J].天然气地球科学,2006,17(3):313 -318.
[16] Liu Q,Liu W.The influence of CO in the carbon isotopic composition of CH4 in closed system pyrolysis experiment with coal[J].Chinese Journal of Geochemistry,2004,23(4):359 -365.
[17] 刘全有,刘文汇,宋岩,等.塔里木盆地煤岩显微组分热模拟实验中液态烃特征研究[J].天然气地球科学,2004,15(3):297 -301.
[18] Powell T G,Boreham C J.Petroleum generation and source rock assessment in terrigenous sequences:an updata[J].Australian Petroleum Exploration Association Journal,1991,31(1):297 -311.
[19] Wilkins R W T,George S C.Coal as a source rock for oil:A review[J].International Journal of Coal Geology,2005,50(1 -4):317 -361.
[20] Powell T G.Development in Concepts of Hydrogen Generation from Terrestrial Organic Matter:Petroleum Resources of China and Related Subjects[M].Texas:Earth Science Series,1988.
[21] Boreham C J,Powell T G.Petroleum source rocks potential of coal and associated sediments:qualitative and quantitative aspects[M]//Hydrocarbons from Coal.Tulas,USA.AAPG Studies in Geology 38,133 -157.
[22] Boreham C J,Horsfield B,Schenk H J.Predicting the quantities of oil and gas generated from australian permian coals,Bowen basin using pyrolytic methods[J].Marine and Petroleum Geology,1999,16(2):165 -188.
[23] 戴金星,陈践发,钟宁宁,等.中国大气田及其气源[M].北京:科学出版社,2003.
[24] 张梅,王东良,朱翠山,等.冀中坳陷苏桥—文安油气田混源油定量认别模式研究(一):原油成因分类及地球化学特征[J].天然气地球科学,2004,15(2):115 -119.
[25] Liu Q,Krooss B M,Hollenstein J,et al.A Comparison of Pyrolysis Products with Models for Gas Generation from Tarim Coal and Its Macerals and Geological Extrapolations[C]//23th Annual Meeting of TSOP,Beijing,2006:164.

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