高邮凹陷吴堡断裂构造带对陈堡油田 油气运移的控制作用

陈堡油田是高邮凹陷东南部吴堡断阶带上的断块油田, 由陈2和陈3两个断块构成,其油气来源和运移路径一直存在多种推测。本文在分析吴堡断裂带断层形成特征, 以及陈堡油田的原油组成和成熟特征基础上, 明确了断层构造对陈堡油田烃源岩的演化、油气运移路径和成藏时期的控制作用。陈堡油田两断块上下层段原油成熟度不同是由于油气充注时期不同以及油气运移路径不同所致。刘五舍次洼烃源岩不同时期形成不同成熟度的原油,吴堡断裂系统的分布以及不同时期断层的活动强度影响断层封闭性, 导致不同时期油气运移路径不同。不同成熟度的油气从刘五舍生烃中心通过与吴①断层相交的羽状小断层先后向吴①断层做“切入式”运移汇流到吴①断层面,再通过不同路径运移到陈堡油田不同储层中形成油气藏。陈堡地区不同断块的油气经历了“同源不同期、同期不同路”的运移过程。

Control of the Wubao Faulted Structure over the Migration of Petroleum in the Chenbao Oilfield of the Gaoyou Depression, Jiangsu

The Chenbao oilfield located in eastern Wubao fault belt comprises faulted reservoirs composed of Chen 2 block and Chen 3 block. The migration of petroleum into the reservoirs from the Liuwushe sag remains a problem unclear to researchers. An analysis of the evolution of the faulted structure in the Wubao fault zone has revealed that faults play an important role in the generation, migration and accumulation of the petroleum. The difference of maturation between the upper reservoirs and the lower reservoirs was caused by different infilling periods and different migration pathways in different epochs, which resulted from the evolution of the faulted structures. The burial history of source rocks led to different maturation degrees of petroleum in different epochs. During the evolution of the faulted structure, the pathways for petroleum migration, which were composed of faults and sandstone beds, changed from time to time, and the petroleum migrated from the source rocks into the Chenbao oilfield. It seems that the petroleum derived from the source rocks first migrated along small faults, then accumulated along the Wu 1 fault, and finally moved upwards into different reservoirs. The migration of the pe-troleum in the Chenbao area has the following characteristics: petroleum came from the same source bed but de-veloped in different periods, and it migrated along different pathways.