基于TTI介质的P波剩余时差裂缝检测技术正演模拟研究

针对塔河油田碳酸盐岩储层中存在的高角度裂缝的检测问题,开展了基于倾斜对称轴的横向各向同性介质(TTI介质)的P波剩余时差裂缝检测技术研究。回顾了TTI介质及其方位NMO剩余时差的基础理论,计算了三维TTI介质中P波的相速度;开发了一套适用于叠前地震道集的P波剩余时差裂缝预测技术,详细论述了其技术流程和具体实现步骤;设计了TTI介质裂缝模型,利用有限差分法模拟计算模型的叠前方位地震道集,根据模拟数据提取的方位NMO剩余时差反演出裂缝发育强度和裂缝角度,与模型设计参数基本吻合,验证了基于TTI介质的P波剩余时差裂缝检测技术的有效性。

To detect the tilt fracture of carbonate reservoirs in Tahe Oilfield,fracture prediction technique based on P-wave residual time-difference of TTI model with tilt axis symmetry is developed and validated.The basic theory of TTI media and NMO residual time-difference are reviewed and the phase velocity of P-wave in 3D TTI media is computed.A fracture prediction technique for P-wave residual time-difference applied for prestack seismic gathers is developed,of which the technical procedures and steps are shown in details.A three-layer numerical model containing one TTI fracture interlayer is designed,with which synthetically seismic azimuth gathers are simulated with finite difference method.The fracture development intensity and fracture angles are inversed by extracted NMO residual time-difference,which are almost the same with the model design parameters.It validates the fracture prediction technology using P-wave residual time-difference based on TTI model.