Relationships between Different Strike Activities of Gaoqing Fault and Huagou Gas Reservoirs Accumulation,Jiyang Depression

The activities in different sections of the Gaoqing fault in the Huagou gas field were analyzed using 3D seismic data.The activities of the fault segment associated with the Huagou gas field were strong during the GuantaoMinghuazhen period,while the activities on east and west sides of the gas field were weak at that time.The Huagou gas field is well corresponding to the strong activity segment of the Gaoqing fault on the plane.The process of gas migration in the Huagou reservoir is divided into two phases:(1)After mantlederived magmatogenetic gas including CO2,N2,and He entered the Gaoqing fault,the gas migrated to the top of the fault by the action of buoyancy or pressure,then the gravitative differentiation occurred.For the top of the fault is closed and both sides of fault is sealed,the gas assembled to some degree in the Gaoqing fault;(2)When gas was accumulated at a large scale in the Gaoqing fault,the gas migrated towards the reservoirs along the two sides of the fault and was accumulated in sandstone.The different activities of gas source fault on strike directions decide the distribution of the carbon dioxide gas,the reservoir bed homologous to the strong activity segment of fault are favorable for the carbon dioxide accumulation.