Analysis Of Petroleum Geological Characteristics Of The Upper Paleozoic In Hefeng Basin

By taking Hefeng Basin for example and depended on previous achievements and materials,and by reference of field geographical survey,geographical profile survey and basin seismic data,this essay concludes the stratigraphic development of Hefeng Basin in northern Xinjiang;it identifies the sedimentary facies of this area and sedimentary characteristics;it finds out the potential source rock development,organic geochemical properties and thermal evolution characteristics.Then it analyzes the reservoir-cap assemblage to analyze the oil and gas resources potential of the area.The target series of strata of Hefeng Basin is the clastic rock member of the upper sub-member of Hujiersite Formation,mainly developing in the southern part of the basin and the dark shale of Hongguleleng Formation of the Upper Devonian Series.Hujiersite Formation of the middle Devonian series is onshore facies sedimentation,mainly weak hydrodynamic environment dominated by argillaceous chippings;Hebukehe Formation of the Upper Devonian Series is mainly constructed by a set of marine facies carbonate rocks and clastic rocks;Hongguleleng Formation of the Upper Devonian Series is a changing process from low energetic coastal plain facies to coastal organic carbonate rocks facies then to coastal clastic rock facies.Rock samples of Hujiersite Formation of the Upper Devonian Series are abundant in organic matters,which are mainly classified into type II and III.They are high in thermal evolution degree up to mature-over mature stage;sample rocks of Hongguleleng Formation of the Upper Devonian Series are abundant in organic matters mainly in type II.They are high in thermal evolution degree up to low-mature stage;sample rocks of Heishantou Formation of Lower Carboniferous Series are medium in organic matters in type II.They are high in thermal evolution up to mature stage.The fissure produced by the authigenic pore and later structure movement of the glutenite and volcanic developed in the upper part of the source rocks becomes favorable reservoir stratum.Mud rocks and volcanic with poor overlying permeability then becomes good cap rock.So,Hujiersite Formation and Hongguleleng Formation of the Devonian System in the southern part of the basin have certain prospect of resource prospection.