Application of orthogonal experiment method in foam flooding system composition and injection parameter optimization

摘要

Excellent composition and injection parameters of foam system are essential for foam flooding to exert mobility control. This study aims to optimize foam composition and injection parameters to maximize foam mobility control. The concentrations of foaming agent and stabilizer, oil saturation, foam quality, and flow rate served as influencing factors in the orthogonal experiment method with resistance factor (RF) as the evaluation index. Results showed that cores with different permeability levels corresponded to a set of optimal injection parameters. The optimal combination scheme significantly improved mobility control relative to all test groups in the orthogonal experiment, proving the effectiveness of this method in optimizing foam flooding parameters. During the analysis of orthogonal experimental data, in addition to the method of intuitive analysis was adopted to study the influence of a single factor on the RF, the influence of multiple factors interaction on the RF was also explored. Confirmatory tests were performed on the optimal parameters of foam flooding obtained by orthogonal experiments, and the foam propagation at different positions of the core was determined. The degree of pressure fluctuation during foam flooding was measured with the standard deviation (SD), which was used to directly measure the strength of the Jamin effect during foam flooding. The RF distribution factor (DRF) was introduced to describe the uniformity of foam seepage resistance along the core axis. DRF was used to study the entrance effect on foam to establish seepage resistance. The propagation performance of foam in porous medium is crucial to maximize its mobility control. Foam injectivity in porous medium should be given attention when optimizing the injection parameters of foam flooding.