Improving water-alternating-CO2 flooding of heterogeneous, low permeability oil reservoirs using ensemble optimisation algorithm. (2017)

• Record Type: Journal Article
• Authors: Liao, Changlin; Liao, Xinwei; Mu, Longxin; Wu, Xianghong; Chen, Jing; Ding, Hongna; Xu, Feng
• Is Part Of: International journal of global warming. Volume 12:Number 2(2017)
• Page Start: 242
• Page End: 260
• Publication Date: 2017
• Subjects: CO2 injection -- CO2 storage -- ensemble optimisation algorithm -- EOA -- water-alternate-gas -- WAG -- oil reservoir; Global warming -- Periodicals; Global warming -- Statistics -- Periodicals; Global warming -- Economic aspects -- Periodicals; Climatic changes -- Periodicals; Climatic changes -- Economic aspects -- Periodicals; Climatic changes -- Environmental aspects -- Periodicals; 363.73874
• Languages: English
• ISSNs: 1758-2083

Abstract

Injecting CO2 into reservoir has been proven to be not only a feasible method for improving ultimate oil recovery, but also reducing CO2 emissions and greenhouse effects. In this paper, the advantages of optimisation algorithm and numerical simulation are combined to establish mathematics model of production optimisation of water-alternate-gas (WAG) flooding. Augmented Lagrange function (ALF) and logarithm transformation (LT) are applied to convert constrained problems into unconstrained ones. The ensemble optimisation algorithm (EOA) is used to solve the latter. Then, the optimisation technology of reservoir production is formed. The optimisation technology is applied in a low permeability oil reservoir to test its feasibility of improving oil production. The results indicate that the CO2 swept efficiency, miscible region and recovery, can be effectively improved by the optimisation technology which increases the economic benefit of the reservoir.