Process for stabilized zirconium triethanolamine complex and uses in oil field applications
AssigneeE.I. du Pont de Nemours and Company
InventorDonald Edward Putzig
Life of this patent
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Abstract
A process for preparing a stable zirconium triethanolamine cross-linking agent comprises contacting a solution of a zirconium triethanolamine complex with water at a temperature of 50° C. to 90° C. at a mole ratio of triethanolamine:zirconium in the range of 3.5:5.5 and at a mole ratio of water:zirconium in the range of 20:1 to 1:1. The stable zirconium triethanolamine complex can be used in a cross-linking composition. Further disclosed are methods to use the composition in oil field applications for hydraulic fracturing and plugging of permeable zones and leaks in subterranean formations.
Claims20
A process to prepare a zirconium cross-linking agent comprising contacting a solution of a zirconium triethanolamine complex with water at a temperature of 50° C. to 90° C. at a mole ratio of triethanolamine:zirconium in the range of 3.5:1 to 5.5:1 and at a mole ratio of water:zirconium in the range of 20:1 to 1:1 for a period of time sufficient to stabilize the zirconium triethanolamine complex in the presence of water having a cross-linking rate when combined with a cross-linkable polymer in the range of 3-8 minutes, achieving a viscosity of 300-1000 centipoise.
A cross-linking composition comprising (a) an aqueous liquid;
- (b) a pH buffer;
- (c) a cross-linkable organic polymer;
- and (d) a solution of a zirconium cross-linking agent prepared by a process comprising contacting a solution of a zirconium triethanolamine complex with water at a temperature of 50° C. to 90° C. at a mole ratio of triethanolamine:zirconium in the range of 3.5:1 to 5.5:1 and at a mole ratio of water:zirconium in the range of 20:1 to 1:1 wherein the cross-linking composition has a crosslinking rate in the range of 3-8 minutes, achieving a viscosity of 300-1000 centipoise.
A method for hydraulically fracturing a subterranean formation comprising introducing into a subterranean formation at a flow rate and pressure sufficient to create, reopen and/or extend a fracture in the formation, (a) an aqueous liquid;
- (b) a pH buffer;
- (c) a cross-linkable organic polymer;
- and (d) a solution of a zirconium cross-linking agent prepared by a process comprising contacting a solution of a zirconium triethanolamine complex with water at a temperature of 50° C. to 90° C. at a mole ratio of triethanolamine:zirconium in the range of 3.5:1 to 5.5:1 and at a mole ratio of water:zirconium in the range of 20:I to 1:1 wherein the cross-linking composition has a crosslinking rate in the range of 3-8 minutes, achieving a viscosity of 300-1000 centipoise.
A method for plugging a permeable zone or leak in a subterranean formation comprising introducing into said zone or said leak, (a) an aqueous liquid;
- (b) a pH buffer;
- (c) a cross-linkable organic polymer;
- and (d) a solution of a zirconium cross-linking agent prepared by a process comprising contacting a solution of a zirconium triethanolamine complex with water at a temperature of 50° C. to 90° C. at a mole ratio of triethanolamine:zirconium in the range of 3.5:1 to 5.5:1 and at a mole ratio of water:zirconium in the range of 20:1 to 1:1 wherein the cross-linking composition has a crosslinking rate in the range of 3-8 minutes, achieving a viscosity of 300-1000 centipoise.
Dependencies are inferred from the claim text.