Experimental studies on the influence of sodium lauryl sulfate on seepage and wetting of water infusion of coalbeds

Abstract

Coal seam water injection is a disaster prevention technology that is commonly used in the mining of underground coal resources. Surfactants are widely used in the coal industry in China to enhance the effect of coal seam water injection. Surfactants may have a potential impact on the seepage stage while enhancing wetting. In order to study the characteristics of surfactants on coal seam water injection, we adopted sodium dodecyl sulfate (SDS) as a surfactant in this study. Based on the research background of the Houwenjialiang Coal Mine in Ordos City, Inner Mongolia Autonomous Region, China, we examined the effect of the surfactant SDS on the seepage stage of coal seam water injection using a laboratory triaxial seepage system. The influence of the surfactant SDS on the coal seam water injection wetting stage was investigated with a laboratory bottom-up imbibition experiment method. The main conclusions are as follows. The addition of surface activity can enhance the wetting effect but impede the seepage stage of coal seam water injection, which deteriorates the permeability coefficient. After the addition of surfactant, the permeability coefficient shows a rapid decrease first and then gradually stabilizes. The reason for the compromise to the permeability coefficient is mainly due to the small cracks or pores caused by the adsorption of SDS, which slows down the flow of the liquid. The addition of surfactants can effectively reduce the surface tension of the liquid, minimize the contact angle, and enhance the coal seam water injection wetting stage. The research results provide valuable information for evaluating coal seam water injection effect and the development of water injection technology.