As an important set of source rocks in the Sichuan Basin,the Sinian Doushantuo Formation source rocks have been scarcely studied.In spite of contributing to the hydrocarbon accumulation of Dengying Formation,the source rocks have not been evaluated for hydrocarbon generation potential.Based on previous researches,and systematic analyses on the development characteristics and distribution of the Doushantuo Formation source rocks in the Sichuan Basin and its periphery,the oil generation,oil discharge,and gas generation during the evolution of kerogen were evaluated and calculated,to preliminarily estimate the natural gas resources orig-inated from the source rocks.The results indicate that,(i)the source rocks are generally underdeveloped within the Sichuan Basin,but there exists three areas of developed source rocks at the northwest,northeast,and south edges of the basin,(ii)the calculated oil gen-eration,oil discharge,and gas generation during the evolution of kerogen are 5 021×108 t,4 519×108 t,and 161×1012 m3,respectively;the hydrocarbon generation of kerogen in the periphery is three times that within the basin;the highest hydrocarbon generation occurs in the western region within the basin,while in the basin periphery,it is the most prominent in the southeastern area;and(iii)the gas resources originated from the Upper Sinian Doushantuo Formation source rocks in the Sichuan Basin are estimated to be 1.09×1012m3,dominated by crude oil cracking gas;the area with the largest gas resources is the western Sichuan Basin,followed by the eastern and the southern areas.
关键词
四川盆地/震旦纪/陡山沱组/烃源岩/生烃潜力/天然气资源量
Key words
Sichuan Basin/Sinian/Doushantuo Formation/Source rock/Hydrocarbon generation potential/Natural gas resources
维普
万方数据