化学工学およびプロセス技術ジャーナル
オープンアクセス

概要

The Interstitial Energy of Immiscible Gas Enhanced Oil Recovery (Igeor) Gases in Porous Media

Ofasa Abunumah, Priscilla Ogunlude, Edward Gobina

The competitiveness of the energy impact of Immiscible Gas Enhanced Oil Recovery (IGEOR) gases (CH4, N2, Air and CO2) in porous media has been determined through an extensive and rigorous experimental approach. Previous studies have stated that the quantity of reservoir oil produced is proportional to the effective energy supplied to the reservoir by the injected fluid. Fluid flow through porous media involves energy interactions or exchanges that can be described by energy continuum or kinetic theory. The energy interactions could be due to geological structures or contact with other pore fluids. Some authors have characterized gas behavior for permeability, velocity, flow rate, and flow regime. However, there is a shortage of studies that explicitly qualifies and quantifies the characterization of energy possession for gases permeating through porous media.Thus, gas interstitial energy has been adopted as an objective function in this research. The optimization requirement for the objective function
is to determine which gases possess the maximum energy impact. An experimental method comprising four gases and five analogous core samples with a varying range of structural parameters (porosities, 3%-24%, pore size, 15 nm-6000 nm) have been employed. The gases were injected into the media at varying pressure (range, 0.2 atm-3.0
atm) and temperature (range, 273 K-673 K) conditions. Results indicate that CH4 CH4 comparatively possesses the most energy thus, making it the most competitive gas in four of the analogous core samples. The normalized interstitial energy possession and potential impact of the gases in IGEOR processes are thus ranked in decreasing
order as CH4 (0.19 J)>Air (0.16 J)>CO2 (0.14 J)>N2 (0.13 J). Air is found to be the most competitive in the fifth core sample that has relatively lower porosity (4%) but with the highest pore size (6000 nm). The coefficient of variation (CV) analysis indicates that the energy impact of N2 (CV=0.66) is the least affected by system heterogeneity and operating variability, such as porosity, pore size, temperature and pressure. This is in contrast to CO2 (CV=0.81) that is the most affected by heterogeneity. The research offers utility to industries such as reservoir engineering, pharmaceutical, and biotechnology. The knowledge can be directly applied in practice for the selection of gases in
fluid porous media processes such as oil recovery, gas separation and fluidized beds.