Performances in Harsh Environments of Water Shutoff and Conformance Control Microgels

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