Characteristics of migration pathway system in Chengdao area

Chengdao area is abundant in multifarious migration pathways as fault,sand body and unconformable surface, which compose a solid migration pathway.With faults as vertical migration pathway,the burial hill or the structural hydrocarbon reservoirs superposes in different geologic ep- ochs near the fracture zone.With unconformable surfaces as the lateral migration pathway,the stratigraphic hydrocarbon reservoir forms in the northern slope zone far from source rocks.With the high-permeability strata as the leading pathway,the lithologic hydrocarbon reservoir distributes in strata around the sag and near source rocks.Most of the hy- drocarbon reservoirs in Chengdao area consist of two or three kinds of migration pathways.This spatial configuration re- suits in a complicated control mode to hydrocarbon distribu- tion.The end and the edge of the migration pathway compri- sing sand body,fault and unconformable surface are signifi- cant places of hydrocarbon accumulation.