Adsorption of surfactant on stratum rocks: Exploration of low adsorption surfactants for reservoir stimulation

Abstract Hydraulic fracturing and self-diverting acid based on viscoelastic surfactant are effective methods to improve the production of low permeability reservoirs. However, surfactants as the main agents of the fluids have a certain impact on oil and gas exploration. The adsorption of surfactant on the rock may change the hydrocarbon flow path and greatly influence the recovery rate. This plagues people in choosing surfactant in reservoir stimulation. In order to make people have a clearer understanding of this issue, we synthesized four representative quaternary ammonium surfactants, including single/Gemini -cationic surfactant and single/Gemini zwitterionic surfactant. The critical micelle concentration (CMC), the adsorption and wettability were researched. The adsorption mechanism of viscoelastic surfactants was investigated through the static adsorption properties and wettability studies of different types of viscoelastic surfactants on carbonate rocks and sandstones with varying concentrations and temperatures. This has important guiding significance for choosing surfactants in the reservoir stimulation.