塔里木盆地麦盖提斜坡东段构造特征与油气聚集关系

摘要

运用断层相关褶皱理论,结合最新的三维地震资料,在精细地震构造解释的基础上,分析了塔里木盆地麦盖提斜坡东段玉北地区断裂构造变形特征,并探讨了该区构造与油气聚集的关系.研究表明:该区构造具有垂向分层变形特征,元古界前寒武系基底局部发育正断层,形成基底断块;古生界发育沿中下寒武统膏岩层滑脱的逆冲断裂,断裂具有统一滑脱面,断裂和褶皱在横向上具有分段性;逆冲断层上盘上古生界发育有不对称(三角剪切)和对称(扇状)褶皱类型,同时伴生褶皱相关裂缝;新生界无明显断裂和褶皱发育,仅在区域上表现为西倾斜坡.断裂、构造裂缝、不整合面构成了上古生界裂缝型储层中油气运移的垂向和横向输导体系;上古生界褶皱膝折带进一步扩展了储集空间,伴生的构造裂缝有效改善了储集性能.受海西晚期和喜马拉雅期构造运动的影响,奥陶系内岩溶储层和上古生界裂缝储层是油气的有利聚集区.%Based on fault-related fold theory and the latest 3D seismic data, the tectonic deformation characteristics in the Yubei area on the eastern Maigaiti slope in the Tarim Basin were analyzed through seismic interpretation, and the relationship between tectonic characteristics and hydrocarbon accumulation was discussed. The study area featured vertically layered deformations. The pre-Cambrian basement developed normal faults and formed fault blocks. The Paleozoic developed slip-thrust faults along the Middle and Lower Cambrian gypsum rocks with a uniform slip surface, and the faults and folds were segmented horizontally. There are asymmetric (trishear) and symmetric (fan) folds in the Upper Paleozoic of the hanging wall, associated with fold-related fractures. Cenozoic did not develop faults or folds, and was represented by a west-tilting slope. Faults, tectonic fractures and unconformities constituted vertical and horizontal carrier systems for hydrocarbon migration in the Upper Paleozoic. The Upper Paleozoic kink bands extended reservoir space, and the associated structural fractures effectively improved reservoir performance. Influenced by the Late Hercynian and Himalayan tectonic movements, the intra-Ordovician karst reservoirs and the Upper Paleozoic fractured reservoirs are favorable accumulations of oil and gas.