Seismic Wavefield Numerical Simulation And Case Study In Loess Tableland Area

The coal resource is very rich in western china, but most of regions that coal resources are covered by loess on the surface. Because of the complicate terrain conditions, special morphologic feature and physical conditions in loess, it is a challenge all the time to carry out seismic prospecting in the area of loess tableland.Taking Bingchang mining area as an example for the technical problems of seismic prospecting in loess tableland, I analyze the sonic logging information of the loess tableland and found the characteristics of stratified distribution of loess. According to the physical parameters of different strata, a loess tableland strata velocity model was established and numerical simulation study was carried out by the use of acoustic, elastic and viscoelastic modeling. The result shows that the simulation of shot records by viscoelastic equation is closer to the actual seismic records in the loess tableland and loess strata is closer to the viscoelastic medium. On the other hand, the signal-to-noise of shot record excited from area of thin loess and bedrock is better than the seismic record excited on the loess tableland. According to the conclusions of numerical modeling, the 3D seismic observation system in the actual terrain condition of loess tableland is designed by use of Ke-Lang software, which used the particular observation system that the receiver lines are arranged to pass through groove and tableland placed leaner, shot points are placed along the groove, the arrangement is fixed, the effective coverage times are relatively uniform, the azimuth angle are distributed in a more reasonable range, the effects of raw record quality is enhanced. Finally, taking Bingchang mining area in Shanxi province as an example, the geology inference of coal-bearing in study area is analyzied, then region of the coal-bearing areas in the study area is delineated again by two-dimensional seismic data, the results show that it is a good means for seismic first, then diling verification. It is also proved that integrated prospecting is greatly improved the success rate of coal geological exploration. 3D seismic prospecting had been carried out in this area and the coal-bearing of prospecting areas and fine geological structures is verified in detail.Nevertheless, also it is needed to further strengthen research and research for seismic prospecting in the loess tableland in order to gain a fundamental technological breakthrough and more wide application.