论文详情
受地面微地震监测范围有限的影响,利用P波初动极性进行水力压裂裂缝破裂面反演时存在较大的不确定性。提出了一种改进的压裂微地震震源机制反演方法,在P波初动极性反演方法的基础上,增加归一化的P波振幅(辐射花样)对震源机制破裂面解进行约束。利用合成记录验证了该方法的稳定性和可靠性。采用该方法在四川盆地某压裂井的地面微地震监测中进行震源机制反演和分析,取得了较好的应用效果。
Geometric distribution for surface microseismic monitoring array is limited.As for certain type of fractures,the uncertainty arises with conventional focal mechanism inversion method based on first-motion of P-wave polarity.We propose an improved method to overcome the difficulty by adopting the normalized P-wave amplitude (radiation pattern) as a constraint of focal mechanism inversion solutions.Synthetic seismic data are then used to verify its stability and reliability.The proposed inversion method is applied to field surface microseismic monitoring data from a hydraulic fracturing well of Sichuan Basin and shows a competing performance.
国家科技重大专项“煤层气井中地球物理勘探技术”(2011ZX05035-003)资助。