塔里木盆地北部富满地区超深层走滑断裂带碳酸盐岩油气差异成藏成因探讨

Origin of differential hydrocarbon accumulation in ultra-deep carbonate reservoirs along strike-slip fault zones in the Fuman area， northern Tarim Basin

乔俊程 常少英 曾溅辉 曹鹏 董科良 王孟修 杨冀宁 刘亚洲 隆辉 安廷 杨睿 文林

Juncheng QIAO Shaoying CHANG Jianhui ZENG Peng CAO Keliang DONG Mengxiu WANG Jining YANG Yazhou LIU Hui LONG Ting AN Rui YANG Lin WEN

塔里木盆地北部超深层走滑断裂体系海相碳酸盐岩油气勘探开发近年来取得了重大突破，但富满油田油气分布与富集特征差异显著，走滑断裂控制下的超深层油气差异成藏机理尚不清楚。研究了富满地区走滑断裂几何结构及其演化过程，探讨其在油气运聚成藏中的作用，分析油气成藏富集机理，提出了油气富集主控因素。研究结果表明：①研究区走滑断裂经历了早期伸展或弱挤压，中期压扭、伸展或平移走滑，晚期定型、继承发育或张扭反转的动力学演化过程。F5断裂带和F17断裂带挤压、剪切和拉张应力交替发育，不同部位演化差异明显，F7断裂带和F16断裂带以剪切应力和拉张应力为主，演化过程相对简单。②演化过程不同的断裂形成了不同的几何结构，造成通源性、输导性与储集性强弱差异配置不同，从而形成了3种不同的油气充注方式。F5断裂带和F16断裂带油气以垂向充注为主，F7断裂带油气以侧向运移调整为主，F17断裂带为垂向充注-侧向运移复合型。③断裂演化过程差异控制了油气充注过程。东部断裂晚期活动性强，喜马拉雅期高成熟裂解气大量充注成藏，形成了“西油东气”的格局。断裂带内不同部位演化过程差异加剧了断裂内油气性质变化的复杂性。④垂向充注型油气藏中通源性、输导性和储集性的耦合配置关系控制了油气富集程度，充注期次差异控制了油气性质变化，油气侧向运移为主的油气藏中储集性及侧向连通程度控制了油气富集程度及油气性质的变化。

In recent years， breakthroughs have been achieved in hydrocarbon exploration efforts in the ultra-deep marine carbonate rocks of strike-slip fault systems in the northern Tarim Basin. However， the Fuman oilfield in the basin exhibits pronounced differences in hydrocarbon distribution and enrichment， with the mechanisms driving the differential hydrocarbon accumulation in ultra-deep reservoirs governed by strike-slip faults remaining unclear. In this study， we investigate the geometric structures and evolution of strike-slip faults in the Fuman area， as well as their role in hydrocarbon migration and accumulation. By analyzing the hydrocarbon accumulation and enrichment mechanisms， we identify the dominant factors controlling hydrocarbon accumulation in ultra-deep carbonate reservoirs in the area. The results indicate that the strike-slip faults in the study area experienced a dynamic evolutionary process consisting of the early extension or weak compression， the middle-stage transpression， extension， or translation slip， and the late-stage stabilization， successive development， or tenso-shear inversion. The F5 and F17 fault zones underwent alternating compression， shear， and tensile stresses， resulting in significant evolutionary differences across their various parts. In contrast， the F7 and Fl6 fault zones were primarily subjected to shear and tensile stresses， leading to relatively simple evolutionary processes. The faults with differential evolutionary processes exhibit distinct geometric structures， resulting in varying configurations of their connection to source rocks， hydrocarbon transport capacities， and reservoir properties. Consequently， three hydrocarbon charging models are formed： vertical charging as represented by F5 and F16， lateral migration for adjustment by F7， and a combination of the former two patterns by F17. The hydrocarbon charging process is governed by the differential evolution of fault zones. The late-stage strong activity of faults in the eastern part of the Fuman area， combined with the charging and accumulation of substantial highly mature pyrolysis gas during the Himalayan movement， results in the formation of a hydrocarbon distribution pattern characterized by “oil in the west and gas in the east”. Furthermore， the evolutionary differences across various parts of the fault zones cause more complex changes in hydrocarbon properties. For reservoirs dominated by vertical hydrocarbon charging， the degree of hydrocarbon enrichment is determined by the coupling of the connection to source rocks， hydrocarbon transport capacities， and reservoir properties of fault zones. Meanwhile， the hydrocarbon properties of the reservoirs are governed by the various hydrocarbon charging stages. For reservoirs dominated by lateral hydrocarbon migration， the degree of hydrocarbon enrichment and hydrocarbon property changes are controlled by their properties and the extent of lateral connections within.

10.11743/ogg20240503