A fully coupled thermodynamically consistent model for gas flow in coals and its numerical implementation

Adelina Lv, Aghighi Mohammad Ali, Hossein Masoumi, Hamid Roshan

Research output: Chapter in Book/Report/Conference proceedingConference PaperOther

Abstract

The simulation of gas production from coal seam gas resources offers significant challenges particularly at large (field) scale. These challenges are often related to the derivation of thermodynamically consistent formulation of the constitutive equations that can capture the physical processes involved and the complexities of their numerical treatment. The developed models use either the continuum or discrete approaches; however, the former is more popular in field-scale numerical simulations. This is because a representative fracture network cannot be often accurately constructed and discrete models also demand significant computational resources. We therefore develop a set of thermodynamically consistent constitutive formulation for gas production from coal seam gas reservoirs using the non-equilibrium thermodynamic approach. The non-equilibrium thermodynamics is particularly adopted to look into time dependency of the coupling processes. The developed continuum model with the assumptions used has similar features to that of the dual permeability formulation with matrix flow being of diffusion type only. The developed constitutive equations are then discretized and solved using Finite Element technique. Advanced numerical treatments such as Stress Patch Recovery are used to ensure accuracy, numerical stability and computational efficiency.

Original languageEnglish
Title of host publication54th U.S. Rock Mechanics/Geomechanics Symposium 2020
Publication statusPublished - 2020
EventUS Rock Mechanics/Geomechanics Symposium 2020 - Virtual, Online, United States of America
Duration: 28 Jun 20201 Jul 2020
Conference number: 54th
https://www.armarocks.org/resources/golden-2020-symposium/ (Website)

Conference

ConferenceUS Rock Mechanics/Geomechanics Symposium 2020
CountryUnited States of America
CityVirtual, Online
Period28/06/201/07/20
Internet address

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