山前带砾石区激发技术优化

The optimization of the excitation technique for the gravel-bearing piedmont zone

复杂山前带是油气勘探的重要领域,具有良好的成藏条件,但由于其复杂的地表、近地表及复杂地下构造,造成该地区地震资料信噪比低,成像精度差。基于山前带砾石区的激发特点,笔者认为在山前激发点选取过程中可借助Google Earth平台进行点位设计,在激发点选取时应采取避高就低、避砾就岩、避陡就缓的原则;小排列层析反演技术能较好地结合小折射和微测井优点,适用于山前表层调查;井深设计时应尽量选择在速度较高、激发能量较强、激发频率高的介质中激发。ZD地区的采集资料显示,采用山前砾石区激发方式能较好地改善地震资料品质。

The complex piedmont zone with good reservoir conditions is an important field of oil and gas exploration. However, the seismic data have a low signal-to-noise ratio and poor imaging accuracy because of the complex surface and near-surface and subsurface structure. Based on the shooting characteristics which exist in the gravel area of piedmont zone the authors consider that we could conduct points design with the aid of Google Earth platform during the process of selecting piedmont shooting points. The principle of selecting low areas instead of high areas, gravels instead of rocks and flattened places instead of steep places should be adopted during the selection of shooting points. Tomographic inversion technique goes for the investigation of the piedmont surface layer. The well depth design should be shot in the areas with high speed, strong shooting energy and high excitation frequency. The data acquisition of ZD district indicates that the shooting way of the piedmont gravel area adopted in this paper can improve the quality of seismic data.