地裂缝三维地震勘查资料数字处理技术探讨

Probe into Geofracture 3D Seismic Prospecting Data Digital Processing Technology

苏锡常地区地裂缝地质灾害发生地区,大都具备地震勘探条件,一是地裂缝在水平方向上的延伸具有方向性,二是在垂向上具有可分辨的拓展深度。在遭受地裂缝破坏的地区,其地震时间剖面将会出现反射波同相轴错断、反射波能量转换、反射层产状变化和反射波增减等特征。根据该区资料试处理效果及有关处理参数的测试原则,确定了地裂缝三维地震勘查资料处理流程:在预处理阶段,着重做好道编辑、静校正和反褶积;在部分时间偏移(DMO)叠加阶段,重点做好速度分析,剩余静校正;在叠加之后偏移之前做好随机去噪及偏移方法的测试;在偏移之后作好反Q滤波,信号增强等处理。另外还可进行波阻抗、振幅层拉平等特殊处理及三瞬处理。通过上述各项资料处理工作,为探测研究地裂缝分布规律提供了可靠的解释依据。

The Suzhou-Wuxi-Changzhou area is a disseminative area of geofracture calamities,because most of the geofractures have extending directivity horizontally and observable prolongation depth vertically,thus provided with seismic prospecting conditions.In the geofracture disrupted area,on seismic time sections will present features of reflection phase axis dislocation,reflection energy conversion,reflecting horizon occurrence variation and reflection wave regulation etc.Based on effect of data testing processing and related processing parameter testing principles have established data processing procedure in geofracture 3D seismic prospecting.In preprocessing stage should attach importance to trace editing,statics and deconvolution;in partial time migration（DMO） stacking stage to velocity analysis and residual statics;after stacking and before migration to random noise reduction and migration method testing;after migration to inverse Q filtering and signal enhancement etc.In addition may carry out special processing of wave impedance,amplitude flattening and ＂three instantaneous＂ processing.Through above data processing can provide geofractures detection and their distribution pattern with reliable interpretation basis.