Pore-Scale Study of Gas Flows in Ultra-tight Porous Media

To enhance ultimate recovery of hydrocarbon gases from unconventional gas resources such as shales, we need to uncover the non-intuitive gas transport mechanisms in ultra-tight porous media. Exploiting our previous and recent pioneering work in modelling rarefied gas flows at micro/nano-scales and in pore-scale characterisation of reservoir rocks, we present an ambitious project to tackle this newly-emerged research challenge through developing direct numerical simulation models and techniques that work on binarised images of concerned porous materials. This work will transform the currently-adopted heuristic approaches, i.e. Darcy-like laws and pore network modelling, into those underpinned by the first principle, and enable the quantification of prediction uncertainty on gas transport associated with the former approaches. Timely support now from EPSRC will provide us crucial resources to shape this emerging research area - understanding and quantifying gas flow physics in ultra-tight porous media.

The proposed pore-scale study of gas flows in ultra-tight porous media is fundamental engineering science. It will allow researchers to thoroughly test widely-used Darcy-like laws that have often been developed on heuristic bases, and to evaluate the pore network modelling for the first time for its usefulness in modelling gas flows in ultra-tight porous media. Therefore, it will transform the current heuristic approaches into those firmly underpinned by first principles. This will provide direct benefit to UK and overseas research institutions and industries in oil and gas sectors. Whenever a new or existing approach is to be shown useful, this study will enable the quantification of uncertainty inherited in that approach, and therefore allow us, for the first time, to make well-informed, reliable and robust prediction of gas recovery rate and producibility where the critical microscopic gas flow needs to be accounted adequately. This will have a profound impact on developing shale gas resources, a policy of UK and many other countries for the purpose of securing energy supply, in particular objectively assessing the economics of shale plays and addressing their potential environmental concerns to living beings.

The multidisciplinary applications of rarefied flows at micro/nano-scales mean this research may then find application in the pharmaceutical, manufacturing, mechanical, chemical, environmental and electronics industries: designers, developers and manufacturers will benefit from an enhanced modelling and design capability, e.g. designing gas chromatographs, and next-generation lithographic machines. In the longer term, our work may be incorporated into simulation tools in cognate industries concerned with non-equilibrium transport physics, including modern materials processing, chemical and environmental engineering (e.g. fluidised chemical reactors, pollutant monitoring), and nano-devices (e.g. quantum point contact nano-devices).