Reservoir Characteristics Of Shahejie Formation And Its Favourable Belt Prediction,ch Aheji Oilfield

Shahejie Formation of Chaheji oilfield is an important potential developing position in Chaheji oilfield,However,due to the lack of doing research on its sedimentary facies which restricts the deep development of reservoir evaluation in the study area,so it is obviously necessary to study sedimentary facies.Faced with the problem mentioned above of study area,we use the theory and method of sequence stratigraphy,and on the basis of taking full use of the data of geology,drilling,logging and 3D seismic.we has studied the sequence stratigraphy of Shahejie Formation in Chaheji oilfield systermatically.the sequence stratigraphic framework has been established.Under the framework,the sedimentary facies study and sedimentary system analysis of the Shahejie Formation in the Chaheji oilfield is carried out respectively,and the favorable reservoir facies belt of the Shahejie Formation in the study area is predicted with the physical property analysis of the reservoir.The research has made the following main understandings:(1)There are 6 distinct sequence boundaries in the Paleogene sediments in the Chaheji oilfield,which are SB1,SB3,SB4,SB5,SB6 and SB7 from bottom to top.Based on this,the sequence stratigraphic framework of Shahejie Formation is established from two aspects of single well analysis and continuous well profile.(2)The sedimentary period of the four to the three section of the three section of the Chaheji oilfield is mainly the Fan Dalta sedimentary system developed in the middle and southern parts,supplemented by the nearshore subaqueous fan deposit in the north,and the salty lake deposits in the southern part of the sand section,the Fan Dalta and the beach bar deposits developed in the middle of the central area,and the Northern Bank of the north.Subaqueous fan deposition is the main form,and The sediment deposition period is mainly dominated by nearshore subaqueous fans in the northern part of the working area.(3)The favorable reservoir facies belt in the three section of the Shahejie Formation is mainly concentrated in the nearshore subaqueous fan and sand dam deposits in the northern part of the industrial area,and the favorable reservoir facies belt in the two section of the sand is mainly concentrated in the sand body of the subaqueous distributary channel of the Fan Dalta front in the middle of the industrial area,and the favorable reservoir facies belt is mainly concentrated in the nearshore subaqueous fan in the north of the industrial area.The sand body in the fan is deposited.(4)Effective trap control oil and gas development scale,favorable reservoir control oil layer development thickness,local existence of lithologic oil and gas reservoir controlled by lithology,oil range is controlled by dominant phase distribution.Based on this understanding,1 favorable targets have been identified in the Es1 x,Es2 and Es3 x segments of the Chaheji oilfield.These targets,together with the other target areas of the Gaojiapu oilfield and the Gaojiapu junction,constitute the direction of the next development and deployment of the research area.