西部Y探区X井烃源岩生烃潜力评价

Evaluation on Hydrocarbon Generation of Source Rocks of Well X in Y Exploration Region

以Z凹陷X井暗色泥岩为研究对象,利用有机碳(TOC)、生烃潜量(S1+S2)和氯仿沥青"A"含量、干酪根显微组分、干酪根碳同位素组成、干酪根元素组成、镜质体反射率(Ro)和孢粉颜色指数(SCI)等分析化验资料,从有机质丰度、类型和成熟度3个方面,对烃源岩的生烃潜力特征进行了研究,结果表明:虽然下白垩统银根组和苏红图组二段烃源岩有机质丰度低,热演化处于低成熟阶段,有机质类型为Ⅲ型,但生烃潜量值高,是Z凹陷的主力烃源岩;下白垩统巴音戈壁组和侏罗系有机质丰度较高,有机质类型为Ⅱ型,热演化处于成熟阶段,但生烃潜量值低,为次要烃源岩。

The dark color mudstones of Well X in Z Depression were taken as the object of study,the advantage of many parameters such as organic matter abundance,the type and maturity of organic matter was used to describe quantitatively or qualitatively the hydrocarbon-generating potential characteristics of the dark color mudstone,through the analysis of organic carbon(TOC),hydrocarbon potential (Pg),chloroform bitumen 'A' ,kerogen maceral,kerogen carbon isotope,kerogen elemental composition,vitrinite reflectance(Ro) and sporinite color index(SCI),etc.The results indicate that the organic matter abundance of the source rocks in Y Region and in the 2nd member of Suhongtu Formation of Lower Cretaceous is lower ,the thermal evolution is at the lower mature stage,and the organic matter type is III,but the hydrocarbon-generating potential is the highest,it is the main hydrocarbon source rock of Z Sag.The organic matter abundance of Lower Cretaceous Bayingebi Formation and Jurassic is higher,where organic matter type isⅡ,their hydrocarbon source rock maturity is at the mature stage,while their hydrocarbon-generating potential is the lowest,therefore,they are the secondary hydrocarbon source rock of Z Sag.