断层活动性和封闭性的定量评价及与油气运聚的关系——以车西洼陷曹家庄断阶带为例

Quantitative Evaluation of Fault Activity and Fault Sealing Property and Its Relationship with Hydrocarbon Migration and Accumulation——By Taking Caojiazhuang Step-fault Zone in Chexi Sag for Example

在定量评价车西洼陷曹家庄断阶带4条生长断层活动性和封闭性的基础上,研究了断层与油气运聚的关系。结果表明,研究区烃源岩大量生烃期与断层停止活动时间具有较好的匹配关系,源上油气藏油气富集程度和宏观分布与馆陶期断层活动时间和活动部位有关;此外,原油地球化学指标特征揭示了油气成藏还受断层切割成熟烃源岩层位控制,研究区3条正向正断层馆陶期活动部位为源上油气藏油气运移的主要通道;泥岩涂抹特征与油气显示关系表明,研究区形成断层侧向封堵的条件为泥岩涂抹势CSP>22,断层泥比率SGR>0.73,泥岩涂抹因子SSF<1.5,其主要影响因素为砂泥岩发育情况、断层断距的大小和断层两侧岩性对置关系,正向正断层封闭性较反向正断层封闭性好。

Based on the quantitative evaluation of activity and sealing property of 4 growth faults in Caojiazhuang step-fault Zone of Chexi Sag,the relationship with hydrocarbon migration and accumulation was researched.The results showed that huge hydrocarbon generating periods matched the time as faults stopped faulting,and the hydrocarbon accumulation degree and macroscopic distribution of hydrocarbon accumulation in upper source rocks had a close relationship with faulting time and site of Guantao Formation.Additionally,oil geochemical index showed that hydrocarbon accumulation was controlled by fault cutting formation where source rocks were matured.The result shows that the main hydrocarbon migration channel of hydrocarbon accumulation in upper source rocks is the site of 3 normal faults where stopping faulting time in Guantao Formation.Mud stone plaster and show of oil and gas indicate that when CSP>22,SGR>0.73,SSF<1.5,fault side blocking is formed,its main influential factors are the development of sandstone and mud stone,fault throw and the lithology on both sides of the faults.The fault sealing of normal faults is better than that of antithetic normal fault.