绕射波分离成像技术在断裂识别中的应用

Application of Diffracted-Wave Separation Imaging Technology in Fracture Identification

断裂是重要的油气储集空间和渗流通道,控制着油气藏的形成与分布。对地下断裂系统分布规律的正确认识是油气勘探乃至后期油气田开发的关键所在。绕射波是地下断裂等小尺度不连续体的地震响应。根据绕射波与反射波在平面波记录上的同相轴形态差异,利用基于平面波预测的绕射波分离技术,从地震记录中将绕射波场分离出来,并单独成像,从而提高小尺度构造的识别精度。数值模型及实际应用效果表明,绕射波分离成像技术对断阶边界的刻画更加清楚,对断裂解释具有一定的指导意义。

Fractures as the important oil?gas accumulation spaces and migration pathways control the formation and distribution of oil and gas reservoirs.Accurate understanding of the distribution of underground fracture systems is critical for petroleum exploration and further oil and gas field development.Diffracted waves are the seismic responses of small?sized geologic discontinuities such as faults and fractures etc.According to the differences of event shapes between the diffracted wave and reflected wave on the plane wave record,and using diffracted?wave separation imaging technique based on plane wave prediction,the diffracted wave field is extracted from the seismic record and imaged separately.Thus the identification accuracy of small?sized structures is improved.The numerical model and actual application result show that the diffracted?wave separation imaging technology can characterize breakpoints more clearly,which could be guidance for fracture interpretation.