Study On The Fault Controlling Hydrocarbon Migration And Regularity Law Of The Hydrocarbon Accumulation In The Fault-fracture Mesh Petroleum Plays

The Carboniferous Donghe sandstone reservoir is the first deep-sea clastic reservoir discovered,in the Donghetang structural belt,Northern Tarim Basin,NW China,and is one of the important exploration strata.However,the formation mechanism of the fault system and its control functions on the reservoir are not known,which restricts the progress of rolling exploration in the Donghetang area of the Tabei area,the lack of a suitable hydrocarbon accumulation system and model in the study area also limits the favorable targets.Based on the study of hydrocarbon accumulation mechanism,this paper integrated with the data of outcrops,seismic,well logging,well core analysis tests,and the internal structure of the fault zone as the study object.And the hydrocarbon accumulation mechanism and model are determined by the numerical simulation based on the fault zone fluid potential.The fault-fracture mesh petroleum plays and their models are established by analyzing the hydrocarbon source rock and hydrocarbon accumulation stages.The strike-slip fault system in the Donghe sandstone was restricted based on the analysis of seismic and well data,which determined the structural pattern in the north-south belt and east-west zonation.The strike-slip fault formation mechanism was proposed based on the characteristics of fault kinematics and geometric,which pointed out that the tension-strain strike-slip fault in the central part of study area was formed by the differential movement of two blocks in the north and south,and the new explanation strike-slip fault is a tear fault with strike-slip properties formed by the adjustment of the fault-differentiation activity.The faults in the fault-fracture mesh petroleum plays of Donghe sandstone are divided into two types in transmission and accumulation type and the sheltered and accumulation type according to the matching relationship between the faulting stage and hydrocarbon accumulation stage.The fault internal structure was divided into two types in single structure and complex structure and eight structural patterns based on the combination relationship between fault core and damage zone,and the structural style of the fault zone of the faults in the Donghe sandstone is divided.Taking the internal structure of the fault zone as the research object,proceeding from the basic theory of fluid potential,the characterization method of fault core is proposed according to the low permeability characteristics of fault core,which divided into potential energy,pressure energy,interface energy and startup energy,and the fault sealing evaluation method was established based on the fluid potential as well.The fluid potential of fault core in the different type of fault zone in the time of hydrocarbon accumulation was obtained based on the fault zone fluid potential model,according to the fault zone characteristics of transmission and accumulation fault in the Donghe sandstone,which taken the strike-slip in fault zone and deformation zone as research object.And the height of hydrocarbon column that the fault core of sandstone self-juxtaposition fault zone in the Donghe sandstone was calculated according to the fluid potential difference between the fault core and reservoir in the time of hydrocarbon accumulation stage.An ant colony algorithm is proposed to stimulate the hydrocarbon accumulation based on the fluid potential fault zone,which according to the comparability between the path of ant foraging and the pathway of hydrocarbon migration.The favorable position of hydrocarbon accumulation was determined,and the hydrocarbon accumulation model are established based on the relationship between the fluid potential of fault core and reservoir,which are according to the simulation results,and the hydrocarbon accumulation process of fault-fracture mesh petroleum plays was established based on the internal structure of fault zone.