Dynamic Effect of Capillary Pressure in Tight Gas Reservoir
Ailin Jia*, Zhikai Lv
Identifiers and Pagination:Year: 2014
First Page: 71
Last Page: 79
Publisher Id: TOPEJ-7-71
Article History:Received Date: 8/05/2014
Revision Received Date: 23/06/2014
Acceptance Date: 23/06/2014
Electronic publication date: 25/7/2014
Collection year: 2014
open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: https://creativecommons.org/licenses/by/4.0/legalcode. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Standard theories for two-fluid flow in porous media assume capillary pressure to be in equilibrium. Numerical simulators often assume that equilibrium capillary pressure–saturation conditions are maintained as changes in fluid saturation are taking place. But recent theories indicate that capillary pressure is perhaps not only a function of saturation but also rate change, which is known as the dynamic effect. In order to investigate effects of the dynamic capillary pressure on fluid flow in tight gas reservoirs, standard theory and present novel pore-scale and Darcy-scale theoretical approaches that account for a dynamic capillary pressure were reviewed in this paper. A dynamic capillary pressure relationship was included in the mathematical and numerical schemes were proposed to simulate tight gas reservoir production, which allows one to identify previously unreported flow scenarios. The numerical schemes were also to modify the Gray and Hassanizadeh equation for infiltration to account for a capillary pressure that depends on the flow velocity. This study is of great benefit to finding out the flow law of tight gas reservoir and the subsequent work of exploitation.