Volume 34: CCUS Technologies for the Carbon Neutrality: Part II

Research and application of foam control technology for CO2 flooding in low permeability reservoir Ren Zhenyu

Abstract

CO2 flooding can effectively improve the recovery factor of low permeability reservoir. However, problems such as strong heterogeneity and gas channeling in low permeability reservoir restrict the development of CO2 flooding. At present, the industrial application of CCUS in Jilin Oilfield is in the stage of large-scale promotion. It is of great significance to study the matching foam control technology suitable for low permeability reservoir with high temperature and acid resistance. In combination with the characteristics of Jilin oilfield oil reservoir, considering the strong penetrability of CO2 and its acidity when encountering water, the mechanism of action of single agent molecular characteristic groups and the evaluation of changes in micro bubble diameter and liquid film. It is clear that high temperature and CO2 medium is the key factors affecting the comprehensive performance of CO2 foam, make full use of the characteristics of strong foaming of long carbon chain, good foam stability of double bonds and inhibition of CO2 adsorption by multiple hydroxide groups to improve the high temperature resistance, CO2 resistance and comprehensive performance of foam,the indoor parallel core displacement experiment shows that on the basis of CO2 flooding, injecting the foam control slug can effectively improve the diversion rate of high and low permeability cores and further improve the displacement efficiency of low permeability cores. The field foam control test of CO2 flooding has played a good role in raising pressure, reducing gas and increasing oil. The gas injection pressure increased by 3.2MPa, gas production decreased by 57.3%, and the cumulative oil increased by 1355t. At present, foam channeling control technology is gradually popularized and applied in Jilin Oilfield, which is of great significance for CO2 flooding in low permeability reservoir to expand the wave reach volume and further improve the oil recovery.

Keywords gas channeling, CO2 foam, Regulation