Comprehensive Prediction Of Clastic Reservoir Of The Fourth Member Of Yingcheng Formation In Changde Area, Songliao Basin

Changde Gas Field in Songliao Basin is a deep gas field located in Datong District,Daq ing City,which has not been effectively developed due to the influence of many gas layers,f ast plane phase change,complex lithology and structure in this area.For this reason,this pap er uses well seismic combined with pre-stack and post-stack reservoir inversion to predict the reservoir of this interval.Based on the study of regional geological characteristics and the core and logging data o f Ying-4 Member,it is clear that the provenance direction of the area is in the west and north directions,and the fan delta plain,fan delta front and shore-shallow lake are respectively de veloped in Ying-4 Member from bottom to top and from southwest to northeast.The water bo dy migrated to the southeast in the period of y4Ⅱ,and reached the maximum in the period of y4Ⅰ.The strata in the northwest are relatively thick,and the thickness of the strata in other d irections has little change,ranging from 10 to 200m.The sedimentation rate near well FS9-1is still fast,and the maximum formation thickness is 350m.On this basis,the reservoir physical properties and structural characteristics of the fourt h member of the study area are studied in depth.It can be seen that the pores of the fourth me mber of the study area are the main reservoir space,and the fractures play the role of seepage channels;The reservoir space types are mainly pore type and pore-fracture type.High-angle structural fracture is the main fracture type,distributed in the slope break zone of the main st ructure,and associated with the fault;The structural deformation is strong,and the most dev eloped structural fractures are diagenetic fractures and structural fractures in areas with large structural amplitude.The fractures in this section are relatively developed,and the strike is n early south-north direction.The proportion of oblique fractures is large,which makes a great contribution to the reservoir.According to the reservoir physical properties and structural characteristics of Ying-4 M ember,the model-based seismic inversion method is optimized,and the comprehensive corr elation of each layer is more than 71%,with a maximum of 86%;The porosity parameter inv ersion is used to distinguish the gas layer from the dry layer,the attenuation gradient geophy sical parameters are used to detect the oil and gas,and the prestack elastic wave impedance i s used to predict the plane distribution of the gas-bearing reservoir.The prediction results sho w that the gas-bearing reservoir of Yingcheng Formation is relatively thick and there are man y gas-bearing intervals;The effective reservoir is mainly composed of glutenite in the front of the fan delta,mainly developed in the slope area,which is distributed in the east-west direct ion in the form of leaves.The effective reservoir is mainly distributed in the FS6-1 and FS6 w ell areas,of which the thickness of FS6-1 well is 111m,and the thickness of FS6 well is 70m.The glutenite in the fourth member of Yingying Formation is generally characterized by th icker slope and depression zones and thinner western pinch-out zones.Due to the lithologic tr aps in the study area,the distribution regularity of effective reservoirs is strong.They are all i n the regional slope zone,concentrated around FS5,FS6,FS7,FS8,FS9 and FS101wells,forming multiple high points with different scales and thicknesses;Affected by the structure,the thickness of gas-bearing reservoir in the west and north of the area is lower than the effect ive thickness range.Therefore,based on multiple factors,a target well location is provided i n the FS6 and FS7 well blocks in the fourth section of Ying Cheng Formation.Therefore,the area of favorable area is about 27.25 km~2,considering reservoir prediction and hydrocarbon detection.