Sealing Mechanism Of The Xiakou Fault Zone And Its Nearby Fault Block In Huimin Sag

By geology,log,core analysis ect, we start the system study of fault sealing mechanism, analyse the inner casue of fault seal oill and gas,solve the key problem of block reservior.By this way,we could develop the mind to find Oil and guide exploration deployment in the futhure.It is siganificant for oill and gas exploring.The sealing ability of faults is mainly determined by the displacement pressure cont rast of fault rock against reservoir, while the displacement pressure of fault rock is cont rolled by shale content and diagenetic grade of fault rock. The shale content of fault rocks depend on the proportion of mudstone thickness of faulted formation, and the positive pressure exerted on the fracture surface determines the diagenetic grade of fault rock. The positive pressure of ractured surface has relation with the fault dip and buried depth of the fault rock while the displacement pressure of reservoir is cont rolled by the shale content and buried depth of reservoir. Setting the alternation relationship between displacement of different shale content rock and burial depth.There are three sealing models at Xiakou faulted zone in the Huimin depression, sandstone and mudstone collocation seal, mudstone smearing seal, carbonate cement filling seal。A new quantitative method for evaluating fault sealing ability is proposed on the basis of sealing rule of displacement pressure cont rast. When oill resource is abundent, oill height reprents fault sealing capacity, the better fault sealing capacity is, the higher oill height is. Through studying the typical resercior,we could build the realitionship between oill height and Oil Controlling fault parameter and find fault sealing mechanism.The results show that the fault sealing in this area is different in time and space, and plays different roles in hydro-carbon migration and accumulation. Xiakou fault controls oil migrating to the gentle slope. The poor fault sealing of east section can form hydrocarbon migration channel through connecting source rock and t rap, while the fault sealing of west section is good, which can form reservoirs by preventing hydrocarbon from migrating. The third or fourth grade faults within gentle slope control hydrocarbon migration and accumulation layer. Further exploration targets should be focused on the fault-blockt rap s in the Es4 formation in the northern of the study area.