酒西坳陷与酒东坳陷下白垩统生烃条件对比研究

Comparison of the Hydrocarbon-Generating Conditions of the Lower Cretaceous from the Jiuxi and Jiudong Depression

论文通过对酒泉盆地下白垩统各层组烃源岩有机地球化学特征的研究,分凹陷分层组对酒泉盆地下白垩统的生烃条件进行了系统的评价,在此基础上对酒西坳陷和酒东坳陷下白垩统的生烃条件进行了横向对比。研究结果表明,酒西坳陷下白垩统烃源岩的生烃条件从中沟组—下沟组—赤金堡组逐渐变好,而酒东坳陷下白垩统的生烃条件具有从中沟组—下沟组—赤金堡组逐渐变差的趋势,也反映出"好的不熟,熟的不好"的生烃特点。酒西坳陷的下沟组和赤金堡组烃源岩是酒泉盆地下白垩统烃源岩中生烃较大贡献者。研究结果对于本区油气勘探具有重要指导意义。

Based on the research of the organic geochemistry characteristics of source rocks,the hydrocarbon-generating conditions of the Lower Cretaceous source rocks in Jiuquan Basin are evaluated systematically by means of being classified by sag and formation.Moreover,the hydrocarbon-generating conditions of the Lower Cretaceous source rocks from the Jiuxi Depression and those of Jiudong Depression are compared.The research results show that the hydrocarbon-generating conditions of the Lower Cretaceous source rocks from the Jiuxi Depression have a tendency of growing better from the Zhonggou Formation to the Xiagou Formation and to the Chijinbu Formation,however,in the Jiudong Depression,there have an opposite tendency showing that the hydrocarbon-generating conditions grow worse gradually from up to down,which reflects the characteristics that the better source rock is immature but the mature source rock is not good.The Xiagou Formation and the Chijinbu formation from the Jiuxi Depression are the main contributors to the hydrocarbon-generation of the Lower Cretaceous source rocks from the Jiuquan Basin.The research results will be of great significance on the exploration of oil and gas in Jiuquan Basin.