水平旋转与极性判断结合的井中微地震资料震相识别方法

压裂井注水注气引起地层岩石破裂,产生的微地震信号震相类型具有随机性,可能是单一P波或S波,也可能是P波、S波同时激发,解决复杂的震相识别与波场分离问题,是井中微地震信号处理的难点之一。根据“P波传播方向与振动方向一致、S波传播方向与振动方向垂直”的特点,以“P波、S波在垂直耦合坐标系分解后两个分量的正负极性呈现出相同或相反规律”作为识别准则，通过水平分量旋转与极性判断结合的方法，实现了井中微地震资料的震相自动识别。模型数据测试证明了该方法对震相识别的准确性、可行性；通过对实际资料射孔数据、压裂多事件数据的测试,验证了该方法对实际资料单个事件震相、多事件震相的识别能力,体现了该方法具有较强的实用性。

When rock rupture is caused by water or gas injection from well fracturing,the phase type of microseismic signal is random.It maybe be single P-wave or S-wave,and also could be P-wave and S-wave excited at the same time.So the solution of the complex microseismic phase identification and wavefield separation is one of the difficulties in the microseismic signal processing.Base on “the propagation direction of P-wave is the same to its vibration direction,the propagation direction of S-wave is perpendicular to its vibration direction”,we built a recognition criterion from “the two component polarities displays the same or opposite rules after P-wave and S-wave decomposed in the vertical coupling coordinates”.The microseismic phase automatic recognition method for borehole microseismic data is implemented by combining horizontal rotation with polarity judgment.The model testing data demonstrate the accuracy,feasibility of the method for microseismic phase identification.With the actual multiple events data from perforating and fracturing exciting,we also validate the practicality of this method to identify microseismic phase of single event and multiple events.