In situ reversible crosslinked polymer gel used in hydrocarbon recovery applications
AssigneeMarathon Oil Company
InventorJames E. Tackett, Jr.
Life of this patent
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Abstract
Reversible crosslinked polymer gels are prepared by adding a degelling agent precursor to a gelation solution during initial preparation. The precursor is integrated into the resulting gel and undergoes hydrolysis to transform into an active degelling agent which reverses the gel. The process has specific utility to hydrocarbon recovery applications where in situ gels are difficult to contact with conventional reversing agents.
Claims16
A process for reversing a crosslinked polymer gel comprising:
- preparing a crosslinked polymer gel comprising a crosslinkable polymer, a crosslinking agent and a degelling agent precursor;
- hydrolyzing said precursor to a degelling agent;
- and
- complexing said degelling agent with said crosslinking agent to reverse said gel.
A process for reversing a crosslinked polymer gel comprising:
- preparing a crosslinked polymer gel comprising an acrylamide-containing polymer, a crosslinking agent and a degelling agent precursor;
- hydrolyzing said precursor to a degelling agent;
- and
- reacting said degelling agent with said gel to reverse said gel.
A process for reversing a crosslinked polymer gel comprising:
- preparing a crosslinked polymer gel comprising an acrylamide-containing polymer, a metal cation-containing crosslinking agent and a degelling agent precursor selected from the group consisting of malonates, oxalates, malonamide, oxalamide and derivatives thereof;
- hydrolyzing said precursor to a degelling agent selected from the group consisting of malonic acid, oxalic acid, and salts thereof;
- and
- reacting said degelling agent with said gel to reverse said gel.
A reversible polymer gel composition comprising an acrylamide-containing polymer, a metal cation-containing crosslinking agent and a hydrolyzable degelling agent precursor selected from the group consisting of malonates, oxalates, succinates, malonamide, oxalamide, succinamide and derivatives thereof.
A process for placing a crosslinked polymer gel in a subterranean formation and subsequently reversing the gel in situ, the process comprising the steps of:
- preparing a crosslinked polymer gel by combining a crosslinkable polymer, a crosslinking agent and a degelling agent precursor in solution;
- injecting said crosslinked polymer gel into a subterranean formation and placing said gel in a desired treatment region of said formation;
- hydrolyzing said precursor to a degelling agent in situ;
- and
- complexing said degelling agent with said crosslinking agent to reverse said gel in situ.
A process for placing a crosslinked polymer gel in a subterranean formation and subsequently reversing the gel in situ, the process comprising the steps of:
- preparing a crosslinked polymer gel by combining a crosslinkable, acrylamide-containing polymer, a crosslinking agent and a degelling agent precursor in solution;
- injecting said crosslinked polymer gel into a subterranean formation and placing said gel in a desired treatment region of said formation;
- hydrolyzing said precursor to a degelling agent in situ;
- and
- reacting said degelling agent with said gel to reverse said gel in situ.
Dependencies are inferred from the claim text.