旋转正断层封闭性研究:来自于砂箱物理模拟实验的启示  

Studies on sealing property of rotational normal faults:Insights from analogue modelling

作　　者：冯桂民 陈书平[1,2] 王中昱 黄学尧 Feng Guimin;Chen Shuping;Wang Zhongyu;Huang Xueyao(State Key Laboratory of Petroleum Resources and Engineering,China University of Petroleum(Beijing),Beijing 102249;College of Geosciences,China University Petroleum(Beijing),Beijing 102249)

机构地区：[1]油气资源与工程全国重点实验室,中国石油大学(北京),北京102249 [2]中国石油大学(北京)地球科学学院,北京102249

出　　处：《地质科学》2025年第2期404-414,共11页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：国家自然科学基金项目(编号:42172138);国家建设高水平大学公派研究生项目(编号:202106440043)资助。

摘　　要：伸展型盆地中的嵌套断层组合,经常发育在滚动背斜,或发育在多米诺式断层上;这些断层会发生旋转,断层倾角随之发生变化,从而影响着断层的封闭性,影响着油气运移和聚集。本文通过设计双三棱柱、可旋转刚性块,利用干砂和黏土模拟伸展条件下的旋转断层,通过观察断层活动和沿断层面的泥岩涂抹情况,来对比分析旋转断层封闭性。模拟实验证明,倾角变缓的断层活动强度大,倾角变陡的断层活动强度小;前者断面紧闭、涂抹强,后者断面开启、涂抹弱。对于倾角变缓的断层,断层活动性和封闭性具有分段特点,下段断面缓、断层紧闭、涂抹强,封闭性好;上段断面陡、断层相对开启、涂抹相对弱,封闭性相对差。这些认识被油田勘探实践所证实,对指导多米诺式断层上部和铲式断层上盘旋转断层的油气勘探具有参考意义。The nested normal faults are common in extensional basins.The faults rotated due to that they occurred either in roll‑overs or in domino‑type faults.The changes of the fault dip angles affected the fault sealing properties controlling the hydrocarbon migration and accumulation.In this study,a pair of rotatable rigid tri‑prisms with dry sands and mud were designed to model rotating normal fault under extensional conditions.The comparative analyses were conducted to get the sealing properties of the rotating normal faults by the observation of the fault activities and mud smear.The results indicated that the faults with decreasing dip angles acted more intensive than that with increasing dip angles.The former was with tight fault planes and intensive mud smear,and the latter with open fault planes and weak mud smear.For the faults with decreasing dip angles,they were of segmentation in fault activities and sealing properties.The relative deep segment had gentler and tighter fault plane with more intensive mud smear and better sealing property than the relative shallow segment.These knowledges were proved by petroleum exploration and would help the petroleum exploration both in top areas of the domino‑type faults and in the hanging walls of listric faults.

关 键 词：砂箱物理模拟 旋转断层 倾角 断层封闭性 油气勘探 

分 类 号：P542[天文地球—构造地质学]