Temperature effect on non-Darcian flow in low-permeability porous media

TL;DR

This study systematically investigates how temperature influences the threshold pressure gradient in non-Darcian flow within low-permeability porous media, revealing that higher temperatures lower the threshold and accelerate its reduction with permeability.

Contribution

First systematic measurement of temperature effects on threshold pressure gradient in non-Darcian flow across various permeabilities.

Findings

Higher temperature lowers the threshold pressure gradient.

Threshold pressure gradient decreases faster with increasing permeability at higher temperatures.

Experimental data fitted to a two-parameter model to characterize interfacial interactions.

Abstract

In low-permeability porous media, the velocity of a fluid flow exhibits a nonlinear dependence on the imposed pressure gradient. This non-Darcian flow behavior has important implications to geological disposal of nuclear waste, hydrocarbon extraction from shale, and flow and transport in clay-rich aquifers. Temperature has been postulated to affect the threshold pressure gradient of a non-Darcian flow; however, the supporting data is very limited. In this study we for the first time report a systematic measurement of the threshold pressure gradient under various permeabilities and temperatures. The results show that a higher temperature leads to a lower threshold pressure gradient under the same permeability and a faster reduction of the threshold pressure gradient with increasing permeability. The experimental data are fitted to a two-parameter model to determine the parameters, h0 and a, which characterize the interfacial fluid-solid interactions and the transition between the Darcy and non-Darcian regimes.