Filtration or fluid loss may be defined as loss of filtrate (water from water based muds) into permeable formations after these zones have been exposed to the drilling fluid through drilling operations.

As a porous formation is exposed to the drilling fluid, mud solids are deposited on the wall of the hole in the form of a filter cake. The rate of fluid loss is propotional to the amount and quality of the filter cake. A thin robust filter cake will assist in reducing formation damage, improve drill rod lubricity and reduce the chances of differential sticking. Fluid loss control additives include cellulose based polymers, lignites, bentonite clays, modified polysaccharides and guar gums.

AMC has a range of products which control fluid loss and may also be used to improve rheological properties of the drilling fluid.