Sensing Cracks in the Earth Using Multiple Scattering and Nonlinear Elasticity

裂缝对我们理解地球资源和结构越来越重要。它们拥有大多数非常规石油和天然气储量，对地热能非常重要，并在常规石油和天然气生产、火山喷发甚至地震中发挥作用。在波场中，它们引入了散射效应，波在地下不同裂隙之间多次反射，可能是裂隙引入了弹性参数对应力和应变的依赖关系，使岩石表现出强烈的弹性非线性。这项研究计划的长期目标是更好地了解如何感知和表征岩石。在短期内，我们的目标是(I)更好地了解裂缝在岩石非线性弹性中的作用，长期目标是使用这些参数来成像裂缝密度和方向，以及(Ii)使用微地震数据集来表征火山区裂缝的散射，以通过散射衰减来表征裂缝，通过本征衰减来表征流体。

Cracks are increasingly important to our understanding of Earth resources and structures. They hold most of the unconventional oil and gas reserves, are important for geothermal energy, and play a role in conventional oil and gas production, volcanic eruptions and perhaps even earthquakes. In wavefields, they introduce scattering effects, in which waves reflect many times between different cracks in the subsurface, and it is likely cracks that introduce the dependence of elastic paramters on stress and strain, making rocks exhibit strong elastic nonlinearity. The long term goals of this research program are to better understand how to sense and characterize rocks. On the shorter term, we aim to (i) to better understand the role of cracks in the nonlinear elasticity of rocks with the long-term goal of using these parameters to image crack density and orientation and (ii) to use microseismic data sets to characterize scattering from cracks in volcanic regions to characterize cracks through scattering attenuation and fluids through intrinsic attenuation.