基于波动方程的微地震震源位置、震源时间及VTI介质各向异性参数联合反演

Wave Equation Based Joint Inversion of Microseismic Source Location,Source Excitation Time and Anisotropic Parameters of the VTI Media

对于非常规油气开发,水力压裂监控的效果取决于对微地震事件的分析、解释。准确的微地震震源位置是关乎施工成败的重要因素。微地震震源位置的准确性与多个参数相关,其不仅依赖于微地震事件的激发时间,同时也依赖于储层介质参数信息,因此进行微地震震源位置、震源时间、储层介质参数的联合反演尤为重要。页岩气储层通常表现出较强的各向异性,VTI介质可对其进行较好的近似描述。基于VTI介质波动方程,本文提出了同时反演微地震震源位置、震源时间以及VTI介质各向异性参数的联合反演方法。数值算例结果表明,该联合反演方法可以通过迭代反演同时得到高精度的微地震震源位置、震源激发时间以及VTI介质各向异性参数信息。

For unconventional oil and gas development,the effectiveness of hydraulic fracturing monitoring depends on the analysis and interpretation of microseismic events.Precise microseismic source location is an important element for the success or failure of construction.The accuracy of microseismic source location is related to several parameters,which depend not only on the excitation time of microseismic events,but also on the information of reservoir media parameters,so it is extremely important to perform the joint inversion of microseismic source location,source time,and reservoir media parameters.Shale gas reservoirs usually develop strong anisotropy,and VTI medium is a good approximate description of shale gas reservoirs.Therefore,in this paper we propose a joint inversion method based on the VTI medium fluctuation equation to simultaneously invert the microseismic source location,source time,and VTI medium anisotropy parameters.The numerical results show that our method is capable of obtaining high-precision information of microseismic source location,source excitation time,and VTI medium anisotropy parameters simultaneously by iterative inversion.