东营凹陷陈南断层构造正反转及其油气成藏关系

Tectonic positive inversion of Chennan Fault and its relation with hydrocarbon accumulation in Dongying Sag

济阳拗陷正反转构造存在与否一直存在争议.以东营凹陷陈南断层为例,通过地震资料及录、测井资料分析证实了陈南断层东营期末正反构造的存在,并进一步对陈南断层的反转特征、反转选择性及其与油气成藏关系进行了研究.结果表明:陈南断层反转区段按其走向分为3段,反转构造样式存在单一型和取直型;陈南断层反转强度因数平均为1.25,多数区段完全反转,北北西走向段反转强度最大;构造正反转对先存断层具有选择性,在相同的应力条件下,边界控盆断层优先发生反转,而反转断层是否发生取值则与先存断层倾角有关.陈南断层的反转时期与生烃高峰期的有效匹配及构造反转形成的良好圈闭环境为油气运移、聚集提供了有利条件.

It has long been debated whether positive inversion tectonics in the Jiyang Depression exists or not. Taking Chennan Fault in Dongying Sag as an example,the positive inversion tectonic of Chennan Fault in the late stage of Dongying is confirmed by the analysis of the seismic data and the drilling and logging data,and then the inversion characteristics,the selection of inversion and the relationship between tectonic positive inversion and hydrocarbon accumulation were systematically studied. The result shows the inversion section of Chennan Fault can be divided into three sections and the inversion tectonic styles takes the forms of single pattern and short cut pattern. The average value of inversion intensity coefficient is 1.25 and most of the section completely reversed in the late stage of Dongying. The inversion intensity of NNW-trending section is the greatest. Tectonics positive inversion is selective to the former fault. In the same stress condition,basin-controlling border fault is prior to invert and the form of short cut pattern is relevant to the fault dip angle. The effective collocation between the inversion time and peak hydrocarbon generating stage and the favorable trap formed by tectonic positive inversion benefit the hydrocarbon migration and accumulation.