Casing annulus remediation system

Abstract

A casing annulus remediation system for lowering a flexible hose into an annulus between strings of casing in a petroleum well by pressurizing the hose so that the hose is rigid and may be forced down the annulus. It is necessary to insert the hose through an outlet into the annulus region for well fluid displacement when pressure builds up in the annulus between casing strings due to leaks in the casing. Pressure build-up in the annulus is reduced by pumping a heavy liquid, sealant or other media through the hose into the annular space experiencing the pressure build-up. A tubing nose is affixed to the lower end of the hose. The hose may be inserted hundreds of feet into the well. Therefore, the hose is pressurized to maintain rigidity to keep the hose from winding about the well during deployment. To keep the hose rigid, internal pressure is maintained in the hose. The tubing nose is provided with a check valve that holds the pressure. Once the hose is lowered to a desired depth, an operator may increase the pressure sufficiently in the hose to open the check valve, thereby allowing heavy liquid to flow out. The heavy liquid displaces the lighter well product, which flows out of the outlet. A terminal fitting assembly is attached to an upper end of the hose and is secured within an access port in the wellhead member. The terminal fitting assembly has a check valve therein, and the hose may be left in the tubing head assembly so that fluids may be pumped through the hose at selected time thereafter.