潜山复杂断裂描述技术——以渤海湾盆地济阳坳陷桩海地区为例

Complex fault interpretation of buried hills: A case study of Zhuanghai region in Jiyang Depression, Bohai Bay Basin

吴笑荷

WU Xiaohe

中国地质大学(北京) 能源学院, 北京 100083 2. 中国石化 胜利油田分公司 物探研究院, 山东 东营 257022

School of Energy Resources, China University of Geosciences, Beijing 100083, China 2. Geophysical Research Institute of SINOPEC Shengli Oilfield Company, Dongying, Shandong 257022, China

渤海湾盆地济阳坳陷桩海地区前新生界潜山应力场复杂、正逆断层判识不准。通过探讨断裂演化的成因机制来判定断层的性质，研究不同性质断层的解释关键技术以准确描述断裂体系，归纳断裂发育样式以明确构造特征。研究表明，桩海地区先后经历了区域抬升—构造平稳—挤压—构造平稳—拉张—压扭—张扭等多期不同应力场作用，印支期、燕山晚期的2次挤压作用形成的逆冲构造奠定了潜山格局，喜马拉雅期的拉张走滑作用使潜山构造复杂化，形成逆断层为主、正断层为辅的断层解释方案。以叠前深度偏移资料为基础，应用地层厚度变化率导数和倾角导数法解释逆冲断层，切片断面联合法解释走滑断层，相干、蚂蚁体、三维可视化等多属性体融合法解释拉张断层。明确桩海地区古生界发育北北东走向逆断层和东西走向拉张断层，主要发育逆冲、负反转、走滑3种断层样式，呈现出复杂的“垒、堑”相间排列格局。

The Zhuanghai oil field is located in the north of the Jiyang Depression, Bohai Bay Basin. Drilling data illustrated that the pre-Tertiary formations of the Zhuanghai area are rich in oil. However, complicated structures developed in the pre-Tertiary formations with unclear fault directions and distributions, which made the exploration of the pre-Tertiary structures very difficult. The nature of faults was determined by considering the mechanism of fault evolution. The key techniques for the interpretation of faults of different natures were studied to accurately describe the fault system and deduce fault development patterns to define the structural features. The Zhuanghai area has experienced several stages of deformation, including regional uplift, stable structure, extrusion, stable structure, tension, tense-shearing and compresso-shearing. The tectonic compressions during the Indosinian and the late Yanshanian periods formed thrust tectonics, which laid the foundation for buried hills. The extensional strike-slips in the Himalayan period made the buried hills more complicated. A fault interpretation was made, mainly focusing on reversed faults. The derivative of stratigraphic thickness change rate and dip can be calculated to interpret reversed faults. Time slices and fault planes were combined to interpret strike-slip faults. Coherent cube, ant-colony and 3D visualization were combined to interpret normal faults. The Paleozoic in the Zhuanghai area developed NNE-trending reverse faults and EW-trending extensional faults, with thrust, negative reversal and strike-slip fault types, showing a complex pattern of "barriers and depressions".

国家科技重大专项“渤海湾盆地精细勘探关键技术（三期）”（2016ZX05006）资助。

https://doi.org/10.11781/sysydz201803439