Unification of fluid flow and electrical conduction in rocks and soils

多孔和破裂的岩石和土壤不仅储存流体，而且允许它们在地球中运动。因此，研究岩石和土壤中的流体流动对于（i）提供安全和丰富的水资源，（ii）石油和天然气的生产，以及（iii）安全处理生活，工业和核废物非常重要。流体流动和电流在基本水平上通过电动现象联系在一起，其中流体流动通过岩石导致电流流动，反之亦然。这些现象很重要，因为在大地震之前和火山周围测量到的电信号通过电动机制与流体流动相关联。对这些机制的准确描述将使我们能够改进对地震和火山的预测。该链接还可以允许通过电测量绘制地球深处的流体流动，帮助开发新的石油，天然气和水钻孔工具，并提供清洁污染土壤的方法。有两个主要问题。首先是缺乏一个交流理论联系流体流动和导电通过电动过程。第二个是目前缺乏对通过岩石和土壤的流体和电流的主要控制影响的理解。本项目旨在通过两条研究途径克服这两个问题。首先是在实验室中测量岩石的动电性质并发展完整的交流理论;其次是测量裂隙和多孔岩石的动电通量并了解控制这些流动的微观结构参数。每个途径将包括实验测量，计算机建模和基础理论的发展，提供工具，使我们能够对任何多孔介质中涉及电气和流体流动的过程进行前所未有的深入了解。这两种途径的结果将结合起来，并应用于现有的地震数据（例如，Parkfield）、火山（例如，Piton la Fournaise）和地下水库。在英国期间，申请人领导了一个小组开发这些新方法，并在拉瓦尔大学开发了一个用于此类研究的实验设施。

Porous and fractured rocks and soils not only store fluids but also allow their movement through the earth. Consequently the study of fluid flow in rocks and soils is highly important to (i) provision of safe and plentiful water resources, (ii) production of oil and gas, and (iii) safe disposal of domestic, industrial and nuclear waste. Fluid flow and electrical flow are linked at a fundamental level by electro-kinetic phenomena, where fluid flow through a rock causes an electrical current to flow or vice versa. These phenomena are important because electrical signals measured before major earthquakes and around volcanoes are linked to fluid flow by electro-kinetic mechanisms. Accurate description of the mechanisms would enable us to improve the prediction of both earthquakes and volcanoes. The link may also allow fluid flow in the deep earth to be mapped from electrical measurements, aid the development of new oil, gas and water borehole tools, and provide methods for cleaning contaminated soils. There are two major problems. The first is the lack of an AC theory linking fluid flow and electrical conduction through electro-kinetic processes. The second is the current lack of understanding of the major controlling influences on fluid and electrical flow through rocks and soils. This project aims at overcoming these two problems by two pathways of research. The first is to measure the electro-kinetic properties of rocks in the laboratory and to develop a full AC theory for it. The second is to measure the electro-kinetic fluxes of fractured and porous rocks and to understand the microstructural parameters that control these flows. Each pathway will include experimental measurements, computer modelling and the development of fundamental theory providing tools that should allow us a previously unparalleled insight into the processes involving electrical and fluid flow in any porous medium. The results of these two pathways will be combined and applied to data existing from earthquakes (e.g., Parkfield), volcanoes (e.g., Piton la Fournaise) and underground reservoirs. While in the UK, the applicant led a group developing these new approaches, and has developed an experimental facility for such research at Université Laval.