GEOCHEMICAL FEATURES OF NATURAL GAS AND APPROACH TO THE PROCESS OF HYDROCARBON ACCUMULATION OF UPPER TRASSICIN MIDDLE SHICHUAN AREA
Received date: 2007-05-21
Revised date: 2007-08-02
Online published: 2007-10-10
Upper Trassic in center Shichuan area is a reservoir forming system with self-g eneration and self-storage.Natural gas is mainly composed of hydrocarb on gas with methane between 88% to 96%.the heavy hydrocarbon has content betwee n 6% to 9%.The non-hydrocarbon gas is mainly composed of H2S and CO2 that co ntent are lower.The drying coefficient (C1/C1-5) is between 5 to 15 an d increased with depth.Methylcyclohexane,heptane and isoheptane of Light hydro carbon in nature gas indicated that nature gas are characterized by their humic-type organic matters.The carbon isotope value of methane is between -39.00‰~-41.00‰ and ethane between-25.00‰~-27.00‰(PDB), which indicated that nat ural gas is typical sapropelic gas.The auther consider that during the upper T rassic continusly subsidence and buried in Yanshan movement,the source rock has entered in maturity and early stage of high maturity.Eroded Strata Thickness w as about 2500m,so the stratum temperature and pressure were dramatically red uced .Exsolution of waterUpper Trassic in center Shichuan area is a reservoir forming system with self-g eneration and self-storage.Natural gas is mainly composed of hydrocarb on gas with methane between 88% to 96%.the heavy hydrocarbon has content betwee n 6% to 9%.The non-hydrocarbon gas is mainly composed of H2S and CO2 that co ntent are lower.The drying coefficient (C1/C1-5 ) is between 5 to 15 an d increased with depth.Methylcyclohexane,heptane and isoheptane of Light hydro carbon in nature gas indicated that nature gas are characterized by their humic-type organic matters.The carbon isotope value of methane is between -39.00‰~-41.00‰ and ethane between -25.00‰~-27.00‰(PDB), which indicated that nat ural gas is typical sapropelic gas.The auther consider that during the upper T rassic continusly subsidence and buried in Yanshan movement,the source rock has entered in maturity and early stage of high maturity.Eroded Strata Thickness w as about 2500m,so the stratum temperature and pressure were dramatically red uced .Exsolution of water-soluble gas and pressure drop and expansion of residual g as in reservoir that was low matured,provides important gas resource for gas ac cumulated in Late Stage and lightens the methane carbon isotope of gas reservoir .
CHEN Yi-Cai, GUO Gui-An, JIANG Yu-Qiang, ZHAO Jun-Xin . GEOCHEMICAL FEATURES OF NATURAL GAS AND APPROACH TO THE PROCESS OF HYDROCARBON ACCUMULATION OF UPPER TRASSICIN MIDDLE SHICHUAN AREA[J]. Natural Gas Geoscience, 2007 , 18(5) : 737 -742 . DOI: 10.11764/j.issn.1672-1926.2007.05.737
[1]王世谦.四川盆地侏罗系—震旦系天然气的地球化学特征[J]. 天然气工业,1994,14(6):1-6.
[2]王兰生,苟学敏,刘国瑜.四川盆地天然气的有机地球化学特征及其成因[ J].沉积学报,1997,15(2):49-53.
[3]陈义才,蒋裕强,郭贵安,等.川中地区上三叠统源岩热演化史模拟计算[J ].西南石油大学学报,2007,29(2):57-61.
[4]Stahl W J.Carbon isotope fractions in natural gases[J].Na-tu re,1976,251:134-135.
[5]戴金星,戚厚发.我国煤成烃气的δ13C1—Ro关系[J].科 学通报,1989,(9):690-692.
[6]徐永昌,刘文汇,沈平.含油气盆地油气同位素地球化学研究概述[J]. 沉积学报,2002,19 (2):161-166.
[7]刘树根,童崇光.川西晚三叠世前陆盆地的形成与演化[J].天然气工 业,1995,15(2):45-59.
[8]郭正吾.四川盆地西部浅层致密砂岩天然气勘探模式[J].天然气工业, 1997,17(3):5-8.
[9]胡惕麟,戈葆雄.源岩吸附烃和天然轻烃指纹参数的开发和应用[J].石 油实验地质,1990,12(4):12-19.
[10]戴金星.利用轻烃鉴别煤成气和油型气[J].石油勘探与开发,1993,2 0(5):26-30.
[11]Thompson.Classification and thermal history of petroleum b-ased on ligh t hydrocarbons [J].Geochim et Cosmochim Acta,1983,47:307-316.
[12]徐永昌.一种新的天然气成田类型——生物热催化过渡带气[J].中国科学:B辑, 1990,(8):975-980.
[13]梁艳,李延钧,付晓文,等.川中—川南过渡带上三叠统须家河组油气全烃地球化学 特征与成因[J].天然气地球科学,2006,17(4):594-598.
[14]王顺玉,戴鸿鸣,王海清.四川盆地海相碳酸盐岩大型气田天然气地球化学特征 与气源[J].天然气地球科学,2000,11(2):10-17.
[15]李延钧,梁艳,雷卞军.川中—川南过渡带西部嘉二段天然气成因与来源[ J].天然气地球科学,2006,17(6):820-823.
[16]刘文汇,徐永昌.煤型气碳同位素演化二阶段分馏模式及机理[J].地 球化学,1999,28(4):359-365.
[17]郝石生,张振英.天然气在地层水中的溶解度变化特征及地质意义[J]. 石油学报,1993,14(2)-12-22.
[18]高胜利,姚文宏,朱广社.四川盆地中西部地区上三叠统压力特征与油气运聚 [J].西北地质,2004,37(2):75-79.
[19]England W A,Mackenize A S,Mann D M,et al.The move-ment and entrapment of petroleum fluids in the subsurface[J].Journal of the Geologi cal Society,London,1987,144:327-347.
[20]Schowalter T T.Mechanics of secondary hydrocarbon mig-ration and en trapment[J].AAPG Bulletin,1979,63(4): 723-760.
[21]Thomas M M,Clouse J A.Scaled physical model of secon-dary oil migration[J].AAPG Bulletin,1995,79(1): 19-29.
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