Study On Application Of Technology In Loess Plateau Area Of Tomographic Static Correction

In recent years,with the deepening of the exploration degree,the difficulty of the seismic data processing is higher and higher,especially that the current exploration region is mostly complex terrain,such as loess tableland,highland and desert.In these areas,the surface is uneven,elevation difference is bigger,and the thickness of low velocity zone is thicker with quickly change,which leads to serious static correction problems.Tomographic static correction can deal with the situation of the dramatic change of velocity and dose not depend on the initial model,which is particularly suitable to such complex surface conditions.In this paper,there are three key technologies in the tomographic static correction.They are ray tracing technology,inversion technology and the first break picking technology.The ray tracing technology includes bending method,shooting method,shooting method with square grids,perturbation method with square grids,minimal path method,and this paper focuses on the study of the minimal path method.Then we give the introduction of inversion method,which includes filter-back projection technology,algebraic reconstruction technology,simultaneous iterative reconstruction technology,and least squares QR-factorization.For the first break picking technology,mutual correlation method and energy ratio method are studied.This paper introduces the flow of tomographic static correction.The actual seismic data from Shanxi area,Papua New Guinea area and Algeria area are processed.And the stack profile of tomographic static correction is compared with the stack profile of elevation static correction and refraction static correction,then the advantage of tomographic static correction in complex area is further highlighted.