准噶尔盆地柴窝堡凹陷达坂城次凹断裂系统及其与油气的关系

Fault systems and their relationships to oil and gas in Dabancheng subsag, Chaiwopu Sag, Junggar Basin

袁浩伟 陈书平 戴鹍 于洪洲 王信棚 汪誉新 赵怀博

YUAN Haowei CHEN Shuping Dai Kun YU Hongzhou WANG Xinpeng WANG Yuxin ZHAO Huaibo

油气资源与探测国家重点实验室(中国石油大学(北京)), 北京 102249 中国石油大学(北京) 地球科学学院, 北京 102249 中国石油大学(北京) 石油工程学院, 北京 102249 中国石化 胜利油田分公司 勘探开发研究院, 山东 东营 257015

State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum(Beijing), Beijing 102249, China College of Geosciences, China University of Petroleum(Beijing), Beijing 102249, China School of Petroleum Engineering, China University of Petroleum(Beijing), Beijing 102249, China Exploration and Development Research Institute, SINOPEC Shengli Oilfield Company, Dongying, Shandong 257015, China

准噶尔盆地柴窝堡凹陷于20世纪80年代末首次取得油气勘探重大突破，此后断裂复杂性以及油气分布不均制约了该区勘探效果。作为凹陷主体的达坂城次凹，二叠纪以来受博格达山逆冲带向南方向、依连哈比尔尕山（简称依山）冲断带向北东方向和黑山向西北方向的强烈挤压，形成了多应力场叠加的压性狭长的对冲构造体系，并导致盆地断裂特征及演化具有复杂性和特殊性。应用测井资料、地震资料以及野外踏勘资料，对达坂城次凹的断裂特征进行了对比研究，并将其划分为博格达南断裂系统、依山断裂系统和黑山断裂系统。其中博格达南断裂系统存在浅层滑脱面，属于含塑性滑脱层的造山楔构造；依山断裂系统为基底卷入式断裂系统。晚海西期、印支期、燕山期和喜马拉雅期构造运动在该区均有地质记录，分别形成了不同规模的断层，其中海西晚期为断裂雏形期，印支—燕山期为断裂定型期，喜马拉雅期为断裂调整期。博格达南断裂系统中滑脱带与中下二叠统烃源岩展布一致，结合构造运动时期、地层沉积特征以及断裂系统，综合分析认为博格达南断裂系统是潜在的油气聚集区。

The Chaiwopu Sag of Junggar Basin experienced a major breakthrough in oil and gas exploration for the first time in the late 1980s, however, the exploration effect in this area is still restricted by the complexity of faults and the uneven distribution of oil and gas. As the main body of the sag, the Dabancheng subsag has been strongly extruded by the Bogda Mountain thrust belt to the south, the Yilian Habirga Mountain (abbreviated as Yishan) thrust belt to the northeast, and the Heishan Mountain to the northwest since Permian. A compressive and narrow ramp structural system superimposed by multiple stress fields was developed, which led to the complexity and particularity of fault characteristics and evolution in the Dabancheng subsag. Approaches including logging, seismic and field geological survey data were applied to study the fault systems in the subsag, including the Southern Bogda Mountain fault system, the Yishan fault system and the Heishan fault system. The Southern Bogda Mountain fault system has a shallow detachment surface, which belongs to an orogenic wedge structure with plastic detachment layers. The Yishan fault system is a basement-involved structure. The Late Hercynian, Indosinian, Yanshanian and Himalayan tectonic movements have geological records in this area, forming different scales of faults. The late Hercynian period is a breakup stage, the Indosinian-Yanshanian period is a fault-shaping period, and the Himalayan period is a fault adjustment period. The distribution of detachment belt in the Southern Bogda Mountain fault system is consistent with that of the Middle-Lower Permian source rocks. Combined with the analyses of tectonic movement period, stratigraphic characteristics and fault systems, the Southern Bogda Mountain fault system is a potential oil and gas accumulation area.

国家重点研发计划 2017YFC0603105;中国科学院战略性先导科技专项（A类） XDA14000000;之子课题6 XDA14010306;国家科技重大专项 2017ZX05005-002-005

https://doi.org/10.11781/sysydz202104569