大牛地气田石炭——二叠系烃源岩生烃潜力

Analysis of the hydrocarbon generation potential of Carboniferous-Permian source rocks of the Daniudi gas field

大牛地气田上古生界石炭—二叠系烃源岩为煤系烃源岩(主要为煤岩和暗色泥岩),有机质类型以Ⅲ型干酪根为主,烃源岩演化成熟度较高,Ro基本在1.5%左右。烃源岩存在3期生烃演化过程,分别为三叠纪期间、侏罗纪期间和古近纪期间。烃源岩(泥岩+煤岩)累计生烃量为8万多亿m^3,煤岩生烃贡献占85%。石炭—二叠系烃源岩现今累计生烃强度高值区主要分布在大牛地气田的东南部、西北部以及西部地区。

The Carboniferous-Permian source rock of the Daniudi gas field is coal-measure（ featuring coal rock and dark mudstone）.Its main type of organic matters is kerogen of type III. Its maturity level is relatively high,whose vitrinite reflectance（ Ro） is around1. 5%. There are three stages of evolution of hydrocarbon generation,respectively in the Triassic period,the Jurassic period and the Tertiary period. The cumulative amount of hydrocarbon generation of the source rocks（ coal rock and mudstone） is more than 8 trillion m^3（ coal as the primary source,accounting for 85% of total output）. The current areas of intensive cumulative hydrocarbon-generating are located in the southeastern,northwestern and western part of the Daniudi gas field.