关键词: 不同时期, 油源断裂, 输导油气, 有利部位, 确定方法

Abstract: To investigate the oil-gas distribution laws in the lower-generation and upper-reservoir type source-reservoir-caprock assemblage in the hydrocarbon-bearing basins, based on studying the oil-gas transport mechanisms and favorable positions in oil-source fault during different periods, and with the use of seismic data, this study determines the positions showing large paleo-activity rate in oil-source fault during the hydrocarbon accumulation activity period and the paleo convex-ridge in oil-source fault during the deactive closed period. Moreover, a set of methods are created to determine the favorable positions for hydrocarbon transport in oil-source fault during different periods, and applied to Jiuzhou, Daliuquan area, Langgu Depression, Jizhong Sag, Bohai Bay Basin. The results show that during the active period of hydrocarbon accumulation (the sedimentary period in Member 2 of Shahejie Formation), six favorable positions for hydrocarbon transport have been developed in six branches of Jiuzhou oil-source fault, including three in Fault F1, two in Fault F₂, and one in Fault F₅. During the deactive closed period (the late sedimentary period of Dongying Formation), twelve favorable positions for hydrocarbon transport are developed in Jiuzhou oil-source fault, including four in Fault F₁, three in Faults F₂ and F₃ for each, one in Faults F₄ and F₅, respectively. Moreover, four favorable positions for hydrocarbon transport in Jiuzhou oil-source fault during the deactive closed period are superposed with those during the active of hydrocarbon accumulation, which is beneficial to hydrocarbon accumulation. Meanwhile, the hydrocarbons discovered in the Mid-Lower Submember 3 of Shahejie Formation adjacent to Jiuzhou oil-source fault are all distributed in those four superposed positions, proving that this method is feasible to determine the favorable positions for hydrocarbon transport in oil-source fault during different periods.

Key words: different periods, oil-source fault, hydrocarbon transport, favorable position, determination method