Drainage flow of a viscous compressible gas from a semisealed narrow conduit is a pore-scale model for studying the fundamental flow physics of fluid recovery from a porous reservoir without fluid injection. The drainage flow is driven by the volumetric expansion of the gas and its mass flow rate has been found previously to be sliplike and proportional to the kinematic viscosity of the gas. Thermal effect on such a drainage flow is studied here by simultaneously solving the linearized continuity, momentum, and energy equations for a semisealed narrow channel with adiabatic walls. It is shown that even in the absence of an imposed temperature drop, gas expansion induces a transient temperature decrease inside the channel, which slows down the drainage process compared to the isothermal model and Lighthill's model. For a given density drop, gas drains out faster as the initial-to-final temperature ratio increases; the transient density can undershoot the final equilibrium value. It is concluded that thermal effect should be carefully considered in order to accurately predict the drainage rate.
ASJC Scopus subject areas
- Computational Mechanics
- Modeling and Simulation
- Fluid Flow and Transfer Processes