Laboratory Experimental Optimization of Gel Flooding Parameters to Enhance Oil Recovery during Field Applications.

Abstract

The profile-control technique is one of the most important enhanced oil recovery (EOR) methods to maintain oil production in the medium and late stages of water flooding. It is necessary to conduct laboratory experiments based on the reservoir parameters from specific oil reservoirs to optimize the operation parameters during the profile-control process. In this work, based on the reservoir properties from Daqing Oil Field (China), we employed three parallel core holders and a square core with one injection well and four production wells to conduct profile-control experiments, and the operational parameters in the field scale were obtained using the similarity principle. The results show that the selected gel system has a good plugging performance and the best injection volume and profile-control radius are 0.3 PV and 6 m, respectively. Additionally, we show the optimized injection speed under different injection pressures when the profile-control radius is in the range of 6–9 m. The optimized displacing radius of the field is in the range of 3–6 m. When the radius is 6 m, the pressure decreases 90% and the corresponding plugging ratio is 81%. The optimized plugging proportion of the fracture length is 50%, and further increase of the proportion has a negligible effect on the production performance. Good field response has been achieved after the implementation of the optimized parameters in the target reservoir. This work, for the first time, systematically studies the operational parameters for the profile-control technique using experimental methods, and it provides the fundamental understandings and implications for enhancing oil recovery in similar types of high-water-cut reservoirs.