Research On Seismic Processing And Interpretation Method Of Qiulitage Structural Zone In Kuqa Foreland Basin

The Kuqa Foreland Basin presents typical structural features of north-south,east-west,and upper and lower stratification.Qiulitage is its second structural belt from north to south,and is an important successor area for oil and gas exploration in the Kuqa foreland.The Qiulitage structural belt has complex surface conditions and underground structures,making seismic exploration difficult,and the exploration degree of the main structure is low.In the past,In the past,single-line and broad-line seismic data could not accurately describe the characteristics of high-steep structures and complex fault systems.It is necessary to conduct in-depth research on high-precision seismic processing imaging and full-layer structure modeling methods for key issues.This paper uses high-density wide-azimuth three-dimensional and high-density wire harness three-dimensional joint seismic exploration data to conduct integrated research on processing and interpretation.In terms of processing,the research mainly focuses on three key points: surface modeling,pre-stack denoising and depth migration that restrict imaging accuracy.Innovative complex mountain micro-logging constrained shallow surface velocity modeling method to improve the static correction accuracy of complex mountains and huge gravel accumulation areas in the piedmont.Create a six-division comprehensive denoising method to improve the signal-to-noise ratio of seismic data between salt and subsalt.Through the five-dimensional interpolation and regularization method,the influence of the irregular observation system in the mountain area on the pre-stack depth migration imaging is reduced.The Kirchhoff migration and reverse time migration methods are studied to overcome the problem of low accuracy of high-steep formation migration and improve the accuracy of seismic imaging of the Qiulitage structural belt.Aiming at the difficulty of interpreting double complex structures,the main research direction is the three-dimensional modeling of the whole layer system.The "three-point method" stratum occurrence extraction method is innovated,which extracts stratum occurrence information from high-precision topographic maps and elevation maps,fine digital geological outcrops wear hats,and control shallow structure modeling.The introduction layer is calibrated through the north-south two-way connection of wells to overcome the problem of inability to be calibrated due to the lack of well data in the main structural area,and a new model of the Double Salt Lake structure is established.The illusion of the subsalt anticline based on time migration was overturned,and the real Qiulitag paleo-uplift and the structural model controlled by the double detachment layer were established.The Paleogene and Neogene detachment imbricated structures with the bottom sandstone of the Jidike Formation and the Suweiyi Formation are newly discovered.A simulative full-depth forward model of the ground surface was established to simulate and verify the rationality of the new structural model.Based on the integrated research method of high-density 3D seismic data processing and interpretation,the intersalt traps of the Paleogene and Neogene double salt lakes were discovered,and carried out a combination of qualitative and quantitative sealing and reservoir cap evaluation to provide a favorable target for further exploration and development of the Qiulitage structural belt.On the basis of the above theoretical analysis and calculation research,this paper proposes a new method for constraining shallow surface velocity modeling with systematic comprehensive information in complex high and steep mountains,as well as TTI anisotropic simulative surface pre-stack depth for low-signal-to-noise seismic data Offset the new process.