Main Controlling Factors And Favorable Target Prediction Of Oil And Gas Accumulation In Sapugao Oil Reservoir In Xiaolinzi Area Of Songliao Basin

Xiaolinzi area is located in the middle and west of Songliao Basin,which is rich in oil and gas.The total amount of oil and gas resources in Xiaolinzi area is large,the remaining amount is large,and the prospect of exploration and development is broad.However,with the exploration in-depth discovery,some wells are located in the dominant channel,but only produce trace gas,mainly produce water;some wells develop multi-layer channel sand body,and the sand body thickness is large,but also produce water;some wells are located in the dominant channel,and develop thick channel sand body,the fault sand configuration relationship is good,can form fault block trap,but still produce water.The occurrence of these drilling failures is bound to be related to the correct understanding of the main controlling factors for the formation of sapugao reservoir in Xiaolinzi area of Songliao basin.Therefore,based on the existing regional geological data,geochemical data,seismic data,logging data,testing data and oil testing data in Xiaolinzi area,this paper systematically analyzes the oil and gas accumulation conditions in five aspects of source rock conditions,reservoir conditions,caprock conditions,trap conditions and transportation conditions,and combines the oil and gas distribution characteristics of each oil layer group in Sapugao oil layer,the main controlling factors of oil and gas accumulation in Sapugao reservoir in Xiaolinzi area are studied,and the favorable target of oil and gas accumulation is further predicted,which provides reference for oil and gas exploration and development in the next stage of Sapugao reservoir in Xiaolinzi area,guides oil and gas field exploitation,increases production and reserves.The main achievements of this study are as follows:?1?The oil and gas of Sapugao reservoir in Xiaolinzi area mainly come from the K₂qn formation source rock,in which the K₂qn¹ formation is the main source rock in the study area,and the K₂qn^2-3 formation are the secondary source rock in the study area.In Xiaolinzi area,the reservoir conditions of Saertu reservoir are relatively good,followed by Gaotaizi reservoir and Putaohua reservoir.The regional mudstone caprock conditions of K₂n^1-2 formation in Xiaolinzi area are the best,followed by Gaotaizi and Saertu oil layers,and Putaohua oil layer is the worst.The trap types developed in Xiaolinzi area include structural trap and micro amplitude structure,among which T₁ reflector trap is the most developed,T_1-1 reflector trap is the second,and T_1G4reflector trap is relatively undeveloped.In Xiaolinzi area,the reflection layers T₁,T_1-1 and T_1G4all determine 6 oil source faults and 7 transport faults,and all determine 6 convex ridges of oil source faults and 10 convex ridges of transport faults;in Xiaolinzi area,the sand body lateral dominant transport channels are relatively developed,and in S₁,S₂,S₃,P_I1,P_I2,P_I3,G₀,G₁,G₂,G₃ and G₄ reservoir groups,the sand body lateral dominant transport channels are developed.?2?The oil and gas reservoir types of Sapugao reservoir in Xiaolinzi area are mainly fault block type,fault nose type,fault lithology composite type,updip pinch out type and fault shelter type.The oil and gas of Saertu reservoir in Xiaolinzi area is mainly distributed in the northwest of the source,mainly enriched in S₁ and S₂ reservoir groups;the oil and gas of Putaohua reservoir is distributed sporadically,and the oil and gas of each reservoir group is poor;the oil and gas of Gaotaizi reservoir is mainly distributed in the southeast of the source,mainly enriched in G₃ and G₄ reservoir groups.?3?The oil and gas accumulation of Sapugao oil layer in Xiaolinzi area is mainly controlled by three factors:fault cap configuration,dominant transport channel and fault sand configuration.The fault cap configuration controls the oil and gas accumulation horizon,dominant transport channel controls the oil and gas accumulation area,and fault sand configuration controls the favorable part of oil and gas accumulation.?4?There are 15 favorable targets for predicting oil and gas accumulation in Sapugao oil layer in Xiaolinzi area,of which 11 are the most favorable targets in Gaotaizi oil layer,4 in Saertu oil layer and no favorable targets in Putaohua oil layer.