Pathway System and Their Matching Relations with Buried Hill Reservoir in Jizhong Depression

Through summarizing the achievement of the formers' research,based on the data of logging,drilling and geochemistry,the types of buried hill reservoir and the characteristics of pathway system in Jizhong Depression were analyzed,and the matching relations between different pathway systems and the types of buried hill reservoirs were discussed according to the discovered buried hill reservoirs.The results showed that the buried hill reservoirs could be divided into buried hill top reservoir,buried hill slope reservoir and inner buried hill reservoir according to the different obstruction conditions of traps;the pathway system of buried hill included fault,unconformity,inner dissolved layer and complex pathway systems;the fault pathway system was effective in terms of space and time due to the influence of carbonate formation,the activity of fault and the accordance of oil generating time,which were favorable to form buried hill top and inner buried hill reservoirs;the unconformity pathway system was constituted of the leached zone beneath the unconformity and the basal conglomerate above the unconformity,which were characterized as double-layer pathway and beneficial to form buried hill top and buried hill slope reservoirs;the inner dissolved layer pathway system was made up of pore-fracture-cave system in the inner formation of buried hill reservoirs which were favorable to form inner hurried hill reservoirs and its development degree was controlled by shale content of interior formation;the complex pathway system was combined with the above single-pathway systems which were characterized as multiform and could lead to hydrocarbon accumulations occurring in different parts of buried hill.