Using surfactants and nanoparticles to improve well productivity and gas condensate recovery

The paper presents a review of theoretical and practical aspects of using surfactants and nanoparticles in the development of gas fields. Traditionally, surfactant compositions are used in highly permeable oil reservoirs in mild conditions, i.e. low temperature and low mineralization of brine water. However, many gas fields are characterized by other conditions: high temperature and high (more than several thousand mg/l) mineralization of brine and low permeability. Traditional compositions are subject to destruction under such conditions and do not perform the tasks assigned to them. For low-permeability reservoirs, where the displacement front is unstable in principle, surfactants become not a means of leveling the profile, but a means of increasing the permeability of reservoir rocks during water injection. The effect of reducing capillary forces is most significant for reservoir systems with low permeability. Reducing capillary forces should improve the displacement parameters. But due to the development of new chemical multicomponent systems, including the use of nanoparticles and specially created volumetric structures in aqueous medium containing surfactants, it is possible to significantly expand the range of applicability of known methods of action. Field tests at a number of sites (mainly in China) demonstrate the technological and economic efficiency of using surfactant and nanoparticle compositions at gas sites to increase gas recovery.