Unification of fluid flow and electrical conduction in rocks and soils

多孔和裂隙的岩石和土壤不仅储存液体，还允许它们在地球上移动。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)生产石油和天然气，以及(Iii)安全处置生活、工业和核废物非常重要。流体流动和电流流动在基本层面上由电动现象联系在一起，即流体在岩石中流动时会产生电流，反之亦然。这些现象很重要，因为在大地震前和火山周围测得的电信号通过电动机制与流体流动联系在一起。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。这一连接还可以通过电学测量绘制地球深处的流体流动图，帮助开发新的石油、天然气和水钻井工具，并提供清理受污染土壤的方法。有两个主要问题。第一个问题是缺乏通过电动过程将流体流动和导电联系起来的交流理论。第二，目前对岩石和土壤中流体和电性流动的主要控制影响缺乏了解。本课题旨在通过两条研究路径来克服这两个问题。第一个是在实验室中测量岩石的电动力学性质，并为之发展一个完整的交流理论。第二是测量裂隙和多孔岩石的电动通量，并了解控制这些流动的微观结构参数。每条途径都将包括实验测量、计算机模拟和基础理论的发展，这些工具将使我们能够以前所未有的方式深入了解涉及任何多孔介质中的电和流体流动的过程。这两个途径的结果将合并并应用于地震(例如帕克菲尔德)、火山(例如皮顿拉·富尔奈兹)和地下水库的现有数据。在英国期间，申请者领导了一个开发这些新方法的小组，并在拉瓦尔大学为此类研究开发了一个实验设施。

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.