High accuracy seismic acquisition technology and its application in loose sand areas

Sanhu area in Qaidam Basin is the fourth largest land gas field in China.Gas reservoirs are buried in shallow Quaternary strata,and are characterized by unconsolidated medium and weak diagenesis.Seismic data obtained by the traditional seismic acquisition has some disadvantages:① Low signal-to-noise ratio and low resolution data cannot meet the requirements of natural gas explo-ration ;② Because of the shallow target formation,it is difficult to recognize abnormality caused by near-surface or gas-bearing layers.This paper introduces a series of high-density seismic acquisition methods,including high-density geometry design,optimized shooting,digital geophone receiving,accurate near-surface structure survey,and high-precision refraction static correction in this area.Application results show that seismic data with the characteristics of high signal-to-noise ratio,high resolution and high fidelity can be obtained using the proposed seismic acquisition technologies.As a result of decreasing the near-surface abnormality,seismic data interpretation precision is significantly improved.