渤海湾盆地临清坳陷西部中生界烃源岩生烃演化

临清坳陷西部中生界烃源岩尚未进行系统研究，制约了该区中生界勘探。利用钻井、地震资料结合地球化学特征对中生界烃源岩进行评价。研究表明：中生界烃源岩为下-中侏罗统坊子组煤层和下白垩统丘城组半深湖相-深湖相暗色泥岩和油页岩，主要分布于丘县凹陷和南宫凹陷。坊子组煤系地层为中等-较好烃源岩，丘城组暗色泥岩和油页岩为中等-好烃源岩。利用构造演化史动态分析了中生界烃源岩的生烃演化过程，分析认为：丘县凹陷中生界烃源岩经历过2期生烃过程，第一期发生在白垩纪中晚期，生成煤层气和少量低熟油;第二期发生在古近纪，达高成熟-过成熟阶段，以生成裂解气为主;南宫凹陷中生界烃源岩在古近纪成熟，主要生成成熟油。下白垩统暗色泥岩厚度巨大，有机质类型较好，可构成自生自储式生储盖组合，具有良好的勘探前景。

Evolution of the Mesozoic Source Rocks in the West Linqing Depression

The Mesozoic source rocks haven't been systematically studied in the west Linqing Depression,which restricted the exploration of Mesozoic in this area.Source rocks were analyzed by drilling and seismic data combined with geochemical data,the study shows that Mesozoic source rocks mainly distribute in Qiuxian Sag and Nangong Sag.They include two types,one is coal seam of Fangzi Formation in Lower-Middle Jurassic,the other is dark mudstone and oil shale formed in semi-deep to deep lake of Qiucheng Formation in Lower Cretaceous.Coal seams of the Fangzi Formation are moderate-to-fair source rocks,dark mudstone and oil shale of the Qiucheng Formation are moderate-to-good oil prone source rocks.Mesozoic source rocks of Qiuxian Sag have experienced two thermal evolution stages,i.e.,the first hydrocarbon generation occurred in the Late Cretaceous,generated coalbed gas and a small amount of low-mature oil;the second oc[JP2]curred in the Paleogene,mainly generated pyrolytic gas.The source rocks of Nangong Sag in Paleogene,mainly generated mature oil.Lower Cretaceous has supper-thick dark mudstone with better organic matter,forming source-reservoir-cap assemblage of self-generation and self-accumulation,which is highly prospective resource.