模型正演在断层阴影带内构造研究中的作用

Research Structure of Fault Shadow Zone by Forward Modeling

刘南 李熙盛 侯月明 董明

LIU Nan LI Xisheng HOU Yueming DONG Ming

中海石油(中国)有限公司深圳分公司研究院, 广东 广州 510240

Research Institute, Shenzhen Branch Company, CNOOC Ltd., Guangzhou, Guangdong 510240, China

陆丰A构造为发育在古隆起背景上的断块构造，由南、北两条断层夹持，位于断层的上升盘，其主块处于两条断层组成的断层阴影带内部，在断层阴影带内地震剖面呈现“上拉”和“下陷”的反射畸变，使得构造存在很大不确定性。为解决这个问题，需要采用正演的手段对构造畸变进行恢复。为此，建立了一系列地质模型进行正演模拟，尝试恢复真实地下构造。分析认为，造成断层阴影区构造畸变的根本原因是断层两盘的速度变化，断距、倾角是影响下伏地层地震反射的主要控制因素。最后，通过研究模型正演结果及实钻井资料，找出了构造畸变的规律，恢复了陆丰A油田ZJ层顶面构造。

Main fault block of Lufeng A Field developed in ancient uplift background, between the south and north fault, located upthrown fault, the main fault block is in the fault shadow zone composed by the two faults, Seismic profiles in fault shadow zone show "pull up" and "sagging". So it is a great structure uncertainty. To solve this problem, need to establish a series of forward modeling, trying to restore the true structure. The paper analyzes the results which cause structure distortion in fault shadow zone is the lateral velocity difference between the upthrow and downthrow, the throw and dip is the key factor that influences the seismic reflection image in fault shadow zone. By analyzing the results of forward modeling and the drilling data, the structure distortion of the law was identified, and the ZJ depth structure of Lufeng A Field was restored.

10.11885/j.issn.16745086.2015.12.04.02