Fault Structure And Its Control On Hydrocarbon Accumulation Of Fuyu Formation In Xingshugang Oil Field

This paper focuses on addressing the theory of fault structure control hydrocarbon accumulation,studies on the geometric pattern,kinematics features and dynamic background of fault systematically,combines with the analysis of accumulation conditions,establishes the fault control hydrocarbon mode of the study area,provides a scientific basis for exploration deployment.The study indicates that there are lots of faults with different scales,characteristics and strikes in Xingshugang oil field,including normal faults,reverse faults,slip-striking faults and inverse faults.Among them,the faults of Fuyu oil layer are dominated by normal fault which strikes mainly NW,NNW and NWW.Three class and four class faults are mainly developed in the study area,with various types of fault assemblage in plane and section.On the basis of fault development scales and activity characteristics,the fault system of Xingshugang oil field can be divided into 6 sets.Fuyu oil layer mainly develop four different faults:faults formed in rift period and actived in depression period,formed in fault-depressing and actived in depression and inversion period faults,formed in depression period,formed in depression period and actived in inversion period faults.Quantitatively analysis of fault activity rate,extensional ratio and tectonic evolution sections indicate that evolution of faults have experienced multiple and cyclic deformation.Xingshugang oil field is settlement center from the period of Quantou formation to MingShui formation and normal tectonic is constructed at the end of depositional time of Mingshui Formation.Faults active intensely during the early stage Cretaceous epoch,qingshankou formation and the late stage of qingshankou formation and Paleogene.The distribution of oil reservoir is obviously controlled by fault,hydrocarbon generation and expulsion and the formation and evolution of traps match well with the fracture structure evolution,T₂ fault provide the condition of oil-gas migration and accumulation,at the same time,the lateral sealing ability of fault is good,easy to form reverse blocking reservoir.