摘要 |
A process and composition are provided for permeability reduction in a hydrocarbon-bearing formation to improve hydrocarbon recovery therefrom. The process includes placement of a crosslinked polymer gel in the treatment region preceded by surface preparation of a gelation solution which is the gel precursor. The gelation solution contains a crosslinkable polymer, a chromium(III)/carboxylate complex crosslinking agent, an inorganic fluoride salt stabilizing agent and an aqueous solvent containing hard salts. The gel is placed in the treatment region by injecting the gelation solution into a well bore in fluid communication with the formation, displacing the gelation solution into the desired treatment region and gelling the solution to completion forming the permeability-reducing gel in situ. The inorganic fluoride salt stabilizing agent promotes the long-term stability of the gel in the treatment region, particularly at high temperatures. |