干旱区生态环境知识资源中心

In the Tarim basin in northwestern China, due to the existence of a thick, shallow, low-velocity layer in a desert area, it is very difficult to acquire high-quality seismic data. The main problems are bad shot and receiving condition, which cause a very low signal-to-noise ratio and low-resolution, undulant hypsography, which makes statics complicated, and surface thick sand stratum, which induces absorption and attenuation of the seismic wave. In order to overcome these difficulties and acquire high-quality seismic data, we adopt the following six methods. (1) Refining investigation of the surface structure for the perfect surface structure model, which serves for choosing better shot and receiver points. (2) Exploding under the water table to guarantee enough shot energy, and embedding the geophone to get a better receiving condition. (3) Selecting dynamite with a bigger diameter to form a better point explosion. (4) Surveying the noise waves to design the best acquisition geometry. (5) Calculating better static correction by refraction tomography constrained by normal surface structure investigation. (6) Compensating the absorbed energy of the seismic wave to gain a high-resolution signal. After applying these methods, we significantly improve the signal-to-noise ratio and the resolution of the seismic data in the main prospecting targets, which enable us to make correct geological interpretation.