Patent attributes
Clean-up additive compositions may be used to enhance the clean-up of VES-gelled aqueous fluids in a wide range of applications and VES fluid compositions, including use of an internal breaker system. The compositions are microemulsions that may include, but not necessarily be limited to, at least one viscosity reducing agent, at least one solubilizing agent, at least one desorption agent and at least one water wetting agent. One non-limiting embodiment of a specific microemulsion includes an unsaturated fatty acid oil, a glycol, a sorbitan ester/ethoxylated sorbitan ester mixture, and an alkyl sulfonate. Microemulsions may perform one or more of the following functions: keeping the reservoir water wet; keeping surface tension reduction low; demulsifying reservoir crude oils and aqueous VES fluids; dispersing and solubilizing the by-products generated when breaking the VES gel; and/or limiting the amount of VES residue on reservoir minerals.
