松辽盆地王府断陷边界正断层差异变形特征及成因机制

Differential deformation characteristics and genetic mechanism of boundary normal faults in Wangfu Fault Depression, Songliao Basin

张希晨 刘晓波 杜长江 周丹妮 李强 张宏祥 梁琰 李磊

ZHANG Xichen LIU Xiaobo DU Changjiang ZHOU Danni LI Qiang ZHANG Hongxiang LIANG Yan LI Lei

中国石油 东方地球物理公司 物探技术研究中心, 河北 涿州 072750 中国石油 辽河油田分公司 勘探开发研究院, 辽宁 盘锦 124010 中国石油大学(北京) 地球科学学院, 北京 102249

Research & Development Center, BGP Inc., CNPC, Zhuozhou, Hebei 072750, China Exploration and Development Research Institute, Liaohe Oilfield Company, PetroChina, Panjin, Liaoning 124010, China School of Geosciences, China University of Petroleum (Beijing), Beijing 102249, China

为揭示松辽盆地王府断陷断层的差异变形特征，深化对边界正断层变形机理的规律性认识，在构造解析及断层差异性分析的基础上，结合构造物理模拟在“连续正演”和“控制变量”方面的优势，探讨边界正断层差异变形的控制因素和成因机制。研究表明：(1)根据断层活动强度划分为4个区域构造演化阶段，王府西边界正断层活动性最强，但由北至南断层倾角逐渐增大，并且在局部呈现“上凸”形态。(2)综合构造物理模拟和实际地质背景表明，边界正断层形态受控于岩性横向变化、同构造沉积作用和基底先存凸起等3个主要因素。边界正断层若同时发育在不同岩性的地层中，或者伴随强烈的同构造沉积作用，都会导致倾角发生改变；此外，断层延伸到坚硬的基底凸起附近会改变延伸趋势，绕过其顶端继续传播，导致在局部出现“上凸”形态。

In order to reveal the differential deformation characteristics of the Wangfu Fault Depression in Songliao Basin and study the regularity of the deformation mechanism of boundary normal faults, this paper, based on the structural analysis and fault differential analysis, discusses the controlling factors and genetic mechanism of differential deformation of boundary normal faults in combination with the advantages of tectonophysical simulation in "continuous forward modeling" and "control variables". The results show that: (1) According to the intensity of fault activity, four regional tectonic evolution stages can be divided. The boundary normal faults in the west of Wangfu Fault Depression is the most active, but the dip angle of the faults gradually increases from north to south, showing a "convex" shape locally. (2) Combining tectonophysical simulation with actual geological background, it is showed that the shape of boundary normal fault was controlled by three main factors, including lateral lithologic change, syntectonic sedimentation and pre-existing uplift of basement. If boundary normal faults are developed in strata with different lithology at the same time, or accompanied by strong syntectonic sedimentation, the dip angle will change. In addition, the extension of the fault near the hard basement bulge will change its trend and continue to spread around the bulge top, resulting in the local appearance of "uplift".

中国石油集团科学研究与技术开发项目“地震处理解释关键新技术研究与智能化软件研发” 2021ZG03

https://doi.org/10.11781/sysydz202303455