A case study of near-surface modeling and high-precision statics in hugethick loess tableland

Abstract

The surface structures are quite complicated in the huge-thick loess tableland in west China, where surface modeling and statistic correction have been the most critical factors that affect the quality of seismic data in the area, the exploration on the shallower-target-layer-based coalbed methane in particular has an even higher requirement on the statistic correction accuracy. A consistency principle for first arrival pickup is presented in order to improve the quality of first arrival according to the surface structure characteristics and the technical requirements on first arrival inversion modeling in the survey area; refraction and chromatographic inversions are adopted to establish a surface model comprehensively with the purpose of calculating the datum static correction; the datum static correction is then used to correct the first break data. The seismic wave field approaching method is used to calculate the residual static correction, which has improved the accuracy of datum static correction, better solved the surface modeling and static correction problems in the exploration of loess tableland and mountains and obtained a high-quality seismic section. This method can also be used as reference and consultation in solving the surface modeling and static correction problems in other complicated areas.