Process for reducing hydrocarbon leakage from a subterranean storage

Abstract

A process is provided for reducing fluid leakage from or into a subterranean storage cavern through the earthen wall of the storage cavern by sealing a relatively high permeability region of the earthen wall, through which the leakage occurs, with a sealing composition in the form of a gel. The process is initiated by preparing a gelation solution from a crosslinkable polymer, a crosslinking agent, and an aqueous solvent. The gelation solution is dispensed into the storage cavern and substantially gelled at the relatively high permeability region, forming a gel that reduces the permeability of the relatively high permeability region and effectively seals the region to fluid flow therethrough. Alternatively, the gelation solution is placed at the relatively high permeability region of the subterranean storage cavern by injecting the gelation solution into an injection well in fluid communication with the relatively high permeability region. The gelation solution is substantially gelled at the relatively high permeability region, forming the permeability-reducing gel. Either of the above-recited alternatives can also be practiced by substantially gelling the gelation solution prior to placement at the relatively high permeability region and placing the resulting flowing gel at the relatively high permeability region.