渤中坳陷活跃烃源岩分布特征及其对PL19-3油气成藏的控制作用

渤中坳陷存在多套烃源岩,烃源岩与油气分布关系的研究对该区油气勘探具有重要的意义。通过演化史分析、盆地模拟及地化分析技术对渤中坳陷活跃烃源岩的分布作了研究。渤中坳陷沙河街组活跃烃源岩主要分布于黄河口凹陷、庙西凹陷和渤东凹陷,而渤中凹陷主体区域沙河街组烃源岩已经达到了高过成熟阶段,仅在边缘分布少许活跃的烃源岩。东下段活跃烃源岩主要分布于庙西凹陷的北段、渤东凹陷以及渤中凹陷的东部边缘。活跃烃源岩的分布控制了油气来源,PL19-3油源及油气成熟度研究表明其油气主要来源于周边活跃烃源岩,渤中坳陷周边沉降中心高成熟度地区对其贡献有限。

Distributional Characteristics of Active Source Rocks in Bozhong Depression and Its Control to the Hydrocarbon Accumulation in Oilfield

There exist many sets of source rocks in Bozhong Depression.The study of the relation between the source rocks and oil and gas distribution has a great significance to the hydrocarbon exploration in the area.The active source rock distribution is studied in Bozhong Depression by analyzing the techniques of evolution history,basin simulation and geochemistry.The active source rocks in Shahejie Formation are mainly distributed in Huanghegou Depression,Miaoxi Depression and Bodong Depression,the major Shahejie source rocks in Bozhong Depression are at highly over-matured stage with only less active source rocks distributed along its margin.The east lower active source rocks are mainly distributed in the north of Miaoxi Depression,Bodong Depression and the east marginal area of Bozhong Depression,where the hydrocarbon resources are controlled by the active source rock distribution.The study of oil source and hydrocarbon maturity in oilfield PL19-3 indicates that oil and gas are mainly from nearby active source rocks,the contribution from the nearby highly matured areas in Bozhong Depression is limited.