The quantitative research and application of the fault lateral sealing ability of structural traps in Weixinan Sag

The Weixinan sag in Beibuwan basin experienced strong tectonic movement during late Oligocene, which formed a number of fault-block and fault-nose structural traps. The fault sealing ability, especially the fault lateral sealing ability, plays an important role in the process of structural trap accumulation. The fault lateral sealing ability mainly depends on the AFPD between the material in the fault zone and the target plate. This paper considers the contribution of two fault plates to the muddy content of the fault zone and quotes the geological model of R_m, which can quantitatively evaluate the fault sealing ability. Through analysing the shale content (R_m) and mudstone smear factor (SSF) of the drilled wells of the Member 3 of Weizhou formation in A oilfield, the quantitative chart of R_m-SSF is established. A quantitative prediction technology of the fault sealing oil column height is established by using the principle of the equilibrium between the appearance of fault press difference (AFPD) and the parallel stratigraphic phase of the resultant force. This paper applies the quantitative analysis technology of the fault lateral sealing ability to the A oil field in the WeiXinan sag, and solves the problem why the oil-water interface of each fault block is inconsistent in the A oil field.