Application Research Of Seismic Exploration Key Technologys In Complex Mountanious Region Of Western China

Foothill thrust belts are the main exploration areas in world's petroliferous basins; they are also the exploration hotspot in this decade.However,there are complex surface features and underground geological structures cohabited in complex foothill belts.These are great challenges to the application of geophysical exploration technology in these areas with complex surface and underground geological conditions.We targeted mainly on Miquan and Ashili areas in southern Junggar basin,and enhanced dramatically the seismic material quality through focusing on the difficulties in exploration technology,controlled the key technology in exploration.1,Based on analyzing traditional seismic survey design method and complex surface and underground foothill's structural characteristics,we proposed a model-based,objective-oriented seismic illumination and optimal seismic survey design method,got practical application results.2,Combining many surface structure investigation methods,we examined complex foothill belt in great detail,which is not only helpful for constructing precise surface structure model,but also fundamentally beneficial to solving complex foothill static correction problem.3,Static correction is difficult in complex foothill,so we take use of tomographical static correction technology constrained by integrated surface structure model,which got great application results.4,Making use of high-precision satellite remote sensing information to pick optimal physical point,we establish precise shot-receiving technology by choosing shot layer based on the relationship between shot lithological feature and shot layer velocity,choosing optimal geophone array based on different surface lithological feature.5,By data processing for enhancing signal to noise ratio and stack imaging on the basis of CRS-OIS technique and imaging technique based on migration and anti-migration,the imaging quality of stack profiles-and migration profiles are enhanced,structureal imaging under the tilted reflective layer,deep and overriding fault get improved effectively.By technique difficulty testing about geophysical exploration in the mountainous areas,we achive two big change on gathing and processing technique:The first chang is from "the combination of well depth,medicinal quantity and detector" technique to "gathing method with different area,belt and segment,line by line,step by step and roll-along selection of shooting conditions,optimal layout design for the object based on model,elaborate surface structure model investigation and the application of complex mountainous areas static correction techniques,etc."The second change is from "simple denoising,CMP stacking,poststack migration technique,etc" to "the combinated multi-domain denoising,CRS stacking,prestack time(depth)migration technique,etc".