Adsorption and retention behaviors of heterogeneous combination flooding system composed of dispersed particle gel and surfactant

Abstract

Heterogeneous combination flooding system composed of dispersed particle gel (DPG) and tetradecyl hydroxyl sulfo betaine (THSB) has been developed as a cost-effective EOR method due to highly beneficial synergistic behavior of improving both sweep efficiency and displacement efficiency. However, the combination flooding system suffered from surfactant loss and chromatographic separation which would raffect synergistic effect of chemical components for extra oil recovery. In this paper, static adsorption and dynamic adsorption of combination flooding system were systematically investigated. Additionally, effects of core permeability, DPG concentration and flow distance on chromatographic separation were also investigated by means of core flooding experiments. Static adsorption experiments indicated that after DPG particles and THSB surfactant were combined, adsorption of THSB surfactant on the quartz sand was lowered while the adsorption of DPG particles was improved, which was attributed to the interactions between DPG particles and THSB surfactant. Dynamic adsorption experiments showed that DPG particle could reduce the surfactant mobility and lead to increase of surfactant retention. Core flooding experiments confirmed that chromatographic separation phenomenon existed when combination flooding system flowed through porous media and the degree of separation phenomenon was lower than that of surfactant and polymer combination flooding system. Smaller surfactant losses, higher particle adsorption and lower chromatographic separation were all responsible for better synergistic behavior of heterogeneous combination flooding system.