| abstract |
A method of controlling leak-off and reducing the concentration of polymers (and/or other materials) in filter cakes formed when oilfield treatment fluids flow through subterranean formation faces involves adding large plate-like degradable and/or non-degradable, particles to polymer or VES-viscosified oilfield treatment fluids, at concentrations of such particles that are less than that required to cover the contacted formation face with a monolayer of such particles. When these large plate-like degradable and/or non-degradable particles are included in the fluid, polymer concentrates to form filter cake only in regions on the formation face (for example fracture faces) not shielded by the large plate-like particles, and the remaining formation face is not covered by concentrated polymer. As a result, the damage due to concentration of polymer and/or other materials in the filter cake during leak-off is reduced, and subsequent clean-up of the filter cake is easier. |