海洋宽线地震成像方法及效果分析

宽线地震勘探技术因其性价比优势在复杂陆地探区油气资源勘探中应用广泛,成功案例较多,但在我国海洋地震勘探领域的成功应用并不多见。此文利用南海北部湾盆地某三维探区的二源三缆一束航海线,结合地下共深度点(CDP)面元的合理定义,系统地进行了基于二维、三维叠前深度偏移算法的多种宽线成像试验,并从成像效果、信噪比等方面进行了详细的对比分析。试验表明海洋宽线的成像处理选取二维算法成像效果较三维算法的成像结果好。对比以前的二维叠前时间偏移结果,工区区域宽线地震资料叠前深度偏移处理取得了较好的应用效果。

Analysis on the Effects of Imaging Methods with Offshore Wide-Line Seismic Data

The wide-line seismic survey has been used successfully and widely in onshore petroleum exploration because of the low cost and good effect.However,offshore wide-line seismic survey application cases have not been reported in China.In order to compare the effects of offshore wide-line data acquired with different configuration,a sail line with 2 sources and 3 streamers was selected from a 3D seismic survey in Baibu Gulf Basin,South China Sea.Combined with the CDP definition,imaging testing has been conducted systematically with 2D/3D Pre-stack Depth Migration (PSDM) on the chosen data.In addition,comparison analysis has been finished about imaging results and S/N ratio.The testing results show that the 2D Kirchhoff PSDM algorithm can achieve better results than 3D Kirchhoff PSDM algorithm in imaging processing of offshore wide-line seismic data.Compared with vintage 2D Prestack time migration data,the application results with 2D PSDM data by regional wide-line survey in the study area are better.