Method for patching or sealing leaks in fluid systems

Abstract

A method for patching or sealing leaks in fluid systems and, in an exemplary application, to a method of patching or sealing leaks in sub-sea hydraulic control lines, leaks in sub-surface or sub-sea safety valves, O-ring leaks of any type, leaks in hydraulic line fittings, tubing thread connection leaks, casing thread connection leaks, glycol hydraulic system leaks, well-head and sub-sea well-head leaks, hanger leaks, and leaks in other types of related down-hole equipment. A pressure- or shear-fibrillatable substance, such as an aqueous fluoropolymer dispersion, a fluoropolymer fine powder, or any other fluoropolymer which is derived from a dispersion polymerization process, is added to a fluid system such as a hydraulic control line, and pressure is then applied to the system. In one embodiment, an aqueous dispersion of polytetrafluoroethylene ('PTFE') particles having a particle size between 0.01 and 10 microns is used. Under the applied pressure and, in one embodiment, under cycling of the pressure, the fluororpolymer particles in the dispersion are forced through the leak site with resulting shear force, causing fibrillation of the individual fluororpolymer particles with resulting intertwining and coalescing of the individual fluororpolymer fibrils at the leak site, wherein the fluororpolymer fibrils form a dense, intertwined and coalesced matrix, impacting and embedding the fibrils within the leak site to effectively seal the leak.