Research Of Static Correction Techniques In The East Margin Of Junggar Basin

In the course of propagation, seismic wave would become delayed and irregular because of the low velocity zone near the surface and the heterogeneous thickness, which can cause the time inaccuracy of the reflected wave, leading to the inaccurate imaging and distortion of formations for reflection eventually. For this situation, static correction technology emerged at the right moment. Static correction aims at minimizing the influences of the surface low velocity zone for the exploration data, especially under complex conditions. Without good static correction, the imaging on the seismic profiles could be false, or even couldn’t image. False apperance can lead to wrong understanding of geologic rules, which makes static correction the key technology and a base work.Complex surface areaes such as desert, Gobi, Piedmont slope, farmland, and residential areas, making up the several typical surface types of shengli oilfield junggar basin east margin exploration area. The large changes of the low velocity layer thickness and lateral velocity cause a serious near-surface correction problem. Based on the analysis of the geological and geophysical characteristics of the several complex surface structures, this aticle studied the EGRM technology(extended generalized reciprocal method) which is the most commonly used, two-dimension interactive iteration refraction wave method, and the seismic first arrival refraction tomographic method. Among the processing applications for the junggar basin east margin seismic data, this aticle proposed a jiont application method of the multiple iterative technologys which combined the field static correction, seismic first arrival ray tomography statics and automatic residual static correction methods, and got obvious effects.