FAULT CHARACTERIZATION AND RESERVOIR FORMING UNDER CONTROL OF “SOURCE-FAULT-TRAP”: A CASE OF THE BOUNDARY FAULTS IN THE SOUTHERN PART OF MIAOXINAN UPLIFT

In order to reveal the petroleum distribution pattern in the southern part of the Miaoxinan Uplift so as to quickly find some oil and gas enriched areas, various approaches are used to seek for favorable paths for efficient migration and accumulation of oil and gas, based on the hydrocarbon reservoir forming stages established for this area. Four boundary faults are depicted meticulously in geometry and kinematics by the recently collected and processed 3D seismic data, the completed well information and logging data. The results show that the faults F1 and F2 have no convex surface ridge, and their activity rate is too small in the period of hydrocarbon reservoir formation, and thus they are disadvantaged for hydrocarbon to migrate up to higher position. However, the F3 fault has an obvious convex surface ridge and most of the activity rate may be as high as 106 m/Ma, so the oil and gas transporting efficiency of this fault is relatively high. The fault F4 has also some convex surface ridges and the activity rate is 63 m/Ma, so it is advantaged for hydrocarbon migration to higher position. Finally combining source rock and the disposition relationship between faults and traps, it is concluded that the fault F3 has good coupling relationship of “source-fault-trap”, and the trap W in the step-fault zone of the southern part of Miaoxinan Uplift has bigger potential in oil and gas enrichment. This method is not only applied in the exploration of QHD33 and LD16 areas of the Bohai Sea, but also provide important reference for oil and gas exploration in the Bohai area.