Improved prediction method of favorable positions for oil and gas transport of active oil-source faults

Key words:  oil-source fault  activity period  transporting oil and gas  favorable position  prediction method before improvement  improved prediction method

Abstract:

In order to more accurately forecast the favorable positions of hydrocarbon transportation during the active period of oil-source faults, the positions with relatively high fault activity intensity and the positions of brittle rock development in the faulted strata were first determined based on the study of the mechanism and favorable positions of oil and gas transportation during the active period of oil-source faults. The superposition of the two improves the favorable positions of oil and gas transportation during the active period of oil-source faults, which in previous studies only the fault activity intensity was considered. The improved method was applied to four branch faults of the Jiuzhou fault in Daliuquan area of Jizhong Depression to forecast the favorable positions of hydrocarbon transportation in the middle and lower submembers of Es₃ during the active period. The results show that the four branch faults of Jiuzhou predicted by the improved method are mainly distributed in the northern part of F1 fault, the southern part of F7 fault, the central and southern part and the northern part of F8 fault, and F9 fault. The predicted distributions are significantly smaller than those predicted by the previous methods, which are mainly distributed in the northern part of F1 fault, the southern and central-northern part of F7 fault, the F8 fault except the southern part and F9 fault. The prediction of the improved method is in good agreement with the oil and gas distribution found in the middle and lower submembers of Es₃ near the four branch faults in Jiuzhou, and the favorable positions of oil and gas transportation predicted by the improved method in the active period of oil-source fault is more in line with the underground reality.