Method of forming fluid impermeable plug in a subterranean formation
AssigneeBaker Hughes, A Ge Company, LLC
InventorSumit Bhaduri
Life of this patent
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Abstract
Water and gas flow into a subterranean reservoir may be reduced by pumping into the reservoir a multi-aldehyde crosslinking agent and a low molecular weight polyacrylamide capable of crosslinking with the crosslinking agent. The reaction product forms a gel plug impermeable to water and gas.
Claims19
A method for reducing the permeability of a permeable zone within a subterranean reservoir penetrated by a wellbore with a ringing gel comprising a gelled reaction product of a polyacrylamide and multialdehyde crosslinking agent, the method comprising:
- (A) pumping into the reservoir through the wellbore:
- (a) the polyacrylamide, wherein the polyacrylamide has a weight average molecular weight between from about 10,000 to about 1,000,000;
- and further wherein the polyacrylamide is either
- (i) at least partially hydrolyzed;
- or
- (ii) at least partially hydrolyzable after being pumped into the wellbore
- (b) the multi-aldehyde crosslinking agent;
- and
- (B) reacting the multi-aldehyde with pendant moieties of the polyacrylamide to render the gelled reaction product and plugging the permeable zone by forming a fluid impermeable plug of the gelled reaction product in the subterranean reservoir;
- and
- (C) reducing permeability of the permeable zone with the fluid impermeable plug.
A method of reducing fluid loss to a first permeable zone of a porous subterranean formation penetrated by a wellbore, the porous subterranean formation further having a second permeable zone, the method comprising:
- (a) pumping into the wellbore and to the first permeable zone:
- (i) a polyacrylamide having a weight average molecular weight between from about 400,000 to about 600,000;
- (ii) a multi-aldehyde crosslinking agent;
- and
- (b) gelling the reaction product of the polyacrylamide and the crosslinking agent;
- (c) reducing the loss of fluid to the first permeable zone and reducing the permeability of the first permeable zone by forming a fluid impermeable plug from the gelled reaction product and plugging the first permeable zone such that the permeability of the second permeable zone is greater than the permeability of the plugged first permeable zone.
Dependencies are inferred from the claim text.