The Structural Characteristics And Its Control To The Hydrocarbon Distribution In Shaobo Area

Gaoyou Sag complex fault zones are well-developed,Shaobo sub-sag is located in the middle low-lying of Gaoyou Sag,mainly under control of Zhenwu,Hanliu fault.Using structural geology,seismic exploration theory and petroleum geology,comprehensively utilizing data of geology,well-logging and seismic,etc,this paper analyses the fault geometry features,the kinematics characteristics as well as tectonic genesis,then predicting favorable traps on the basis of the research area of fracture characteristic and favorable hydrocarbon accumulation conditions analysis,this evaluation has a great significance for the rolling exploration in the region.Through 3D seismic interpretation,the detailed explanation has been done in the studied area.The results of the interpretation and geometric research of the shaobo sub-sag indicates that Zhen?1?fault is level-I boundary fault which control the development of depression,while Zhen?2?fault and Hanliu fault are level-II fault.The planar combined types of faults in the area are skew-type,parallel-aligned and grid-type.Fault section combination types mainly include developmental ladderlike combination,"Y"glyph combinations and graben.Selected lines of different tectonic position in the study area,compiled the structural evolution sections,combined with the calculation of the average fault throw and fault activity rate,this thesis holds that Zhen?1?fault started in the period of K₂t₂+E₁f_1,peaked in the period of E₁f_4,weakened apparently in the period of E₂s,stopped in the period of Ny.Zhen?2?Fault started slightly later than the first.Hanliu fault started in the period of E₂f_4,peaked in the period of E₂d₂-E₂s_2,weakened apparently in the period of Ny.Level-II faults formed in the period of E₂d-E₂s.According to the analyses of source rock,cap rock condition,migration condition and so on,three kinds of hydrocarbon accumulation modes were brought up,there are as follows:?1?hydrocarbon accumulation mode of distributary channel sands in slope area.?2?hydrocarbon accumulation mode of turbidite sands in sag area.?3?hydrocarbon accumulation mode of distributary channel sands in fault terrace area.Through the analysis of the structure and hydrocarbon accumulation,we propose two favorable areas which have good potential and in need of further study.