Accurately estimating event locations is of significant importance in microseismic investigations because this information greatly contributes to the overall success of hydraulic-fracturing monitoring programs. Full-wavefield time-reverse imaging (TRI) using one or more wave-equation imaging conditions offers an effective methodology for locating surface-recorded microseismic events. Although, to be most beneficial in microseismic monitoring programs, the TRI procedure requires using accurate subsurface models that account for elastic media effects. We have developed a novel microseismic (extended) PS energy imaging condition that explicitly incorporates the stiffness tensor and exhibits heightened sensitivity to isotropic elastic model perturbations compared with existing imaging conditions. Numerical experiments demonstrate the sensitivity of the microseismic TRI results to perturbations in P- and S-wave velocity models. Zero-lag and extended microseismic source images computed at selected subsurface locations yield useful information about 3D P- and S-wave velocity model accuracy. Thus, we assert that these image volumes potentially can serve as the input into microseismic elastic velocity model building algorithms.

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微地震数据的PS能量成像条件第1部分：3D各向同性介质中的理论和应用

在微地震研究中，准确估计事件位置非常重要，因为该信息极大地有助于水力压裂监控程序的整体成功。使用一个或多个波方程成像条件的全波场时间反向成像（TRI）为定位表面记录的微地震事件提供了一种有效的方法。尽管在微地震监测程序中最有利，但TRI程序需要使用考虑弹性介质效应的精确地下模型。我们已经开发了一种新颖的微震（扩展）PS能量成像条件，与现有的成像条件相比，该条件明确包含了刚度张量，并且对各向同性弹性模型扰动表现出更高的敏感性。数值实验证明了微地震TRI结果对P波和S波速度模型中摄动的敏感性。在选定的地下位置计算的零时滞和扩展的微震源图像会产生有关3D P波和S波速度模型精度的有用信息。因此，我们断言这些图像量可能可以作为微地震弹性速度模型建立算法的输入。