Faculty of Engineering and Physical Sciences, University of Southampton, Southampton SO17 1BJ, UK.
CFD Laboratory, Institute of Continuous Media Mechanics, Perm 614013, Russia.
Philos Trans A Math Phys Eng Sci. 2023 Apr 17;381(2245):20220090. doi: 10.1098/rsta.2022.0090. Epub 2023 Feb 27.
Mechanical vibrations can alter static and dynamic distributions of fluids in porous matrices. A popular theory that explains non-destructive changes in fluids percolation induced by vibrations involves elasticity of a solid matrix and compressibility of fluids. Owing to strong damping, elastic and acoustic deformations always remain bounded to narrow zones (a few centimetres) near the source of vibrations. However, field trials prove the existence of the effects that are induced by vibrations in geological reservoirs on a longer scale (100 m). In this study, we develop a non-elastic theory, assessing the time-averaged effects induced by small-amplitude high-frequency vibrations. We examine the immiscible liquid/liquid displacement flows in a capillary (which is a building element of a porous matrix) subjected to translational vibrations. We find that strong-enough vibrations alter the shapes of menisci and change the rates of displacement flows. We find that vibrations slow down or even stop the displacement flows (which is contrary to a common expectation that vibrations help to release fluids from a porous matrix). This article is part of the theme issue 'New trends in pattern formation and nonlinear dynamics of extended systems'.
机械振动可以改变多孔介质中流体的静态和动态分布。一种流行的理论解释了振动引起的流体渗流的非破坏性变化，该理论涉及到固体基质的弹性和流体的可压缩性。由于强烈的阻尼，弹性和声波变形总是局限于振动源附近的狭窄区域（几厘米）。然而，现场试验证明，在更长的尺度（100 米）上，振动会在地质储层中产生影响。在这项研究中，我们开发了一种非弹性理论，评估小振幅高频振动引起的时均效应。我们研究了在平移振动下处于毛细状态的不相容液/液置换流（这是多孔基质的一个组成部分）。我们发现，足够强的振动会改变弯月面的形状，并改变置换流的速率。我们发现，振动会减缓甚至停止置换流（这与普遍的预期相反，即振动有助于将流体从多孔基质中释放出来）。本文是“扩展系统的模式形成和非线性动力学的新趋势”主题特刊的一部分。
