The use of solids free brines as completion fluids like calcium bromide has given rise to the need for methods of fine solids removal. Filtration of clear brines has become a major concern to operators. The mechanics of removal include sieving, bridging, adsorption, and settling within the porous matrix. Parameters such as flow density or velocity and pressure drop are important. The classification of current filtration techniques will include the type of removal mechanism whereby the specific filter operates, the effect of operating conditions on efficiency, and what kind of performance can be expected.