复杂构造三维地震勘探观测宽度与接收线距选择分析

SELECTION OF OBSERVED WIDTH AND RECEIVING LINE INTERVAL FOR COMPLEX STRUCTURES DURING 3D SEISMIC EXPLORATION

塔里木盆地库车地区地表起伏剧烈,施工难度大,地下构造复杂、地震成像精度低。在勘探生产中,三维观测系统的面元尺度、覆盖次数、观测方位宽窄、接收线距等参数选择至关重要,直接影响勘探投入及复杂目标成像质量。通过对库车山地二维、三维数学模型和物理模型的正演模拟资料分析,认识到库车坳陷复杂构造叠前偏移成像应该优先选择较小的接收线距,并尽可能达到一定观测宽度,大可获得较为清晰的目标成像效果。

Kuche area in Tarim Basin is characterized by rugged topography and complex underground structures, resulting in seismic imaging with low accuracy and very difficult seismic exploration. It is significant to choose some parameters during a 3D observation, including din scale, multiplicity, observed view, and receiving line interval, which can affect directly both exploration investment and imaging quality. In this study, a lot of forward-simulation data from 2D and3 D mathematical and physical models are analyzed. And it is deemed that for the Kuche depression with complex structures, the smaller receiving line interval should be the first choice during a prestack migration imaging, further to achieve a certain observed width as possible. Therefore, a clear imaging effect may be obtained.