Study On The Relation Between Fault Activity And Hydrocarbon Accumulation In Bonan Depression

Faults are important structures in exploration and production of hydrocarbon, which exert significant control on the migration, entrapment, and subsequent compartmentalization of hydrocarbon. There are lots of faults in Bonan Depression, among which there are larger faults that can be able to link hydrocarbon source rocks in the deep and shallow trap, also with the development of sub small faults associated with advanced secondary shallow reservoirs.With the comprehensive use of the structural geology, geophysics, logging geology, statistics, geochemistry, et al., combined with the application of fault activity rate, balanced cross-section analysis, fluid inclusions analysis, reservoirs anatomy, quantitative and qualitative analysis of the integration of technology, based on analyzing structural pattern and formation characteristics, the research is applied in the following procedures. First, geometric characterizations of faults are analyzed, with the important research of fault-activity capability, and fault-seal capacity is analyzed as a key.Hydrocarbon migration stages are confirmed through the researches on source rock characterization. Various migration pathways can be divided on the different structural belts. It is more important that fault-activity control to migration and accumulation of hydrocarbon can be restored in oil and gas migration stages. Meanwhile, the distribution of effective faults should be confirmed. That is to say, hydrocarbon migration vertically in large-scale in northern steep slope zone and deep depression zone, and hydrocarbon migration laterally in long-distance in southern gentle slope zone. In the end, based on study of typical petroleum reservoirs, this paper established six kinds of hydrocarbon accumulation models in controlling of faults in there zones. There are controlling reservoir model of horsetail faults and controlling reservoir model of listric faults in the steep slope zone. There are controlling reservoir model of ramp-flat faults and controlling reservoir model of reverse Y shape faults in depression zone. And there are controlling reservoir model of step faults and controlling reservoir model of horst in gentle slope zone.