Cebo F-SEAL is an acid-soluble, fibrous lost circulation material, composed of synthetic resin-bound stone wool. Cebo F-SEAL is used as an additive for preventing and resolving loss of circulation in concentrations of up to 20 kg/m³. The product’s fibrous composition builds a structure against high-permeable formations on which a Bentonite fluid can create a filter cake; this effectively prevents drilling fluids from seeping into the surrounding formation. Cebo F-SEAL is an inorganic, non-fermenting product and can be easily mixed.