Time Matching and Its Control Effect on Gas Migration and Accumulation Period of Caprock, Source Rock, and Fault in Ed Formation of X sag

Abstract

In order to study the distribution regulation of natural gas in the Ed formation of X sag, the time matching of caprock and source rock - fault in the Ed formation X sag and its control effect in the gas migration and accumulation period was studied. It is based on the study of development and evolution characteristics of source rock, fault and caprock in Ed formation. The relationship has been analyzed between the natural gas migration as well as the time matching of source rock and fault and the time matching of caprock as well as source rock and fault of accumulation and preservation of gas. The results indicate that time matching relationship of source rock and fault is the best in N2m-Q sedimentary period in Ed of X sag, then is in Ed1 sedimentary period, and the worst is Es2 and Es3 sedimentary period. N2m-Q and Ed1 sedimentary period should be the main periods of gas migration from Es3 and Es1 source rocks to overlying Ed along oil source faults. Time matching relationship of caprock, source rock, and fault in Ed of X sag is good in N2m-Q sedimentary period, and mudstone caprock of Ed3 and Ed2 can seal gas migration from Es3 and Es1 source rock to Ed formation along oil source fault, which should be the main period of gas accumulation in Ed formation. However, mudstone caprock in Ed3 and Ed2 cannot seal gas from Es3 and Es1 source rock to overlying Ed formation along oil source faults in Ed1 sedimentation period, its time matching relationship of caprock, source rock, and fault is bad, and it is not the main period of gas accumulation in Ed formation.