Performances in Harsh Environments of Water Shutoff and Conformance Control Microgels

Microgels are polymeric chemicals specifically designed for enhanced water shutoff and conformance/ profile control applications. Microgels are micron-size particles which are preformed, stable, fully water soluble and size-controlled with a narrow distribution. Being non toxic, according to the OSPAR environmental tests, and available under powder form, they are also particularly well suited for offshore operations. Their long-term stability was checked at temperatures up to 165°C (329°F). In porous media, microgels allow a controlled permeability reduction to water through a monolayer adsorption. When injected in a heterogeneous reservoir, unlike conventional polymer-based systems, microgels invade significantly less the low permeability layers than the high permeability ones, thanks to their low viscosity in solution as well as to steric effects.