Seismic Sedimentary Reaserch Of Shawan Formation In The Three-Dimensional Area Of Su-1-West,Junggar Basin

The three-dimensional area of Su-1-West is the study area that is located in the northwest margin of Junggar Basin.The regional structure is located in the west flank of Chepaizi uplift in the Western uplift of Junggar Basin.The Neogene Shawan Formation in this area has great exploration potential.Therefore,this research takes it as an object to make the sedimentary type of Shawan Formation clearly and restore the Paleo-sedimentary environment of this period.Finally,the sedimentary model of Shawan Formation can be established to guide oil and gas exploration in this area.This paper carries out research on seismic sedimentology of Shawan Formation in Su-1-West by means of seismic data and drilling?logging?data,and combines with the previous achievements.As is known to all,seismic sedimentology is an important method to study sedimentology by using seismic data.Many techniques it contains can greatly improve the quality of seismic data and the reliability of interpretation.Therefore,this paper applies these characteristics of seismic sedimentology,which included denoising,phase adjustment,frequency division and spectral inversion,to increase the signal-to-noise ratio and resolution of seismic data.Thus,the distribution characteristics of sedimentary facies on the plane and profile can be reflected accurately.On the other hand,based on the optimized seismic data,the sequence stratigraphy of Shawan Formation is divided into three fourth-order sequences?SQN₁s₁,SQN₁s₂,SQN₁s₃?by using the method of well-seismic combination.SQN₁s₁ can be divided into three fifth-order sequences?SQN₁s₁³,SQN₁s₁²,SQN₁s₁¹?.Among them,SQN₁s₁roughly corresponds to the first member of Shawan Formation,SQN₁s₂ roughly corresponds to the second member of Shawan Formation,and SQN₁s₃ roughly corresponds to the third member of Shawan Formation.Finally,by making instantaneous stratal slices and extracting interlayer attributes in the sequence framework,and combining with the characteristics of single well,the sedimentary facies of each sequence of Shawan Formation are identified.The study shows that the sedimentary types of Shawan Formation in the three-dimensional area of Su-1-West are various,mainly consisting of shore-shallow lake,beach bar,braided river delta,meandering river,and terminal fan.The sedimentary types change with the lake level,climate change,provenance sup ply and other factors from SQN₁s₁ to SQN₁s₃.