Solid borozirconate and borotitanate cross-linkers
AssigneeE.I. du Pont de Nemours and Company
InventorsDonald Edward Putzig, Peter Jernakoff
Life of this patent
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Abstract
A process is provided to prepare solid borozirconate and solid borotitanate cross-linkers, which comprises contacting zirconium or titanium complex with alkanolamine at particular mole ratios of boron, zirconium or titanium and alkanolamine. Use of the cross-linkers in compositions for oil field applications such as hydraulic fracturing and plugging of permeable zones are also disclosed.
Claims21
A process for preparing a solid complex suitable for cross-linking a fracturing fluid which comprises:
- (a) contacting a metal complex, wherein the metal is zirconium or titanium, with alkanolamine at a mole ratio of 0.8 to 2.2 moles of alkanolamine per mole of metal in an alcohol solvent to form a first mixture;
- (b) contacting the first mixture with a boron compound at a mole ratio of about 0.25 to 3 moles of boron per mole of metal to produce a second mixture;
- (c) maintaining the second mixture for a sufficient period of time for the reaction to reach equilibrium;
- and (d) removing the volatiles from the product of step (c) to form a solid borometalate cross-linker.
A cross-linking composition which comprises:
- (A) an aqueous liquid;
- (B) a pH buffer;
- (C) a cross-linkable organic polymer;
- and (D) a solid borozirconate or borotitanate complex, prepared according to a process comprising (a) contacting a metal complex, wherein the metal is zirconium or titanium, with alkanolamine at a mole ratio of 0.8 to 2.2 moles of alkanolamine per mole of metal in an alcohol solvent to form a first mixture;
- (b) contacting the first mixture with a boron compound at a mole ratio of about 0.25 to 3 moles of boron per mole of metal to produce a second mixture;
- (c) maintaining the second mixture for a sufficient period of time for the reaction to reach equilibrium;
- and (d) removing the volatiles from the product of step (c) to form a solid borometalate cross-linker.
A method for hydraulically fracturing a subterranean formation, which comprises introducing into the formation at a flow rate and pressure sufficient to create, reopen, and/or extend one or more fractures in the formation, a cross-linking composition comprising:
- (A) an aqueous liquid;
- (B) a pH buffer;
- (C) a cross-linkable organic polymer;
- and (D) a solid borozirconate or borotitanate complex, prepared by a process comprising:
- (a) contacting a metal complex, wherein the metal is zirconium or titanium, with alkanolamine at a mole ratio of 0.8 to 2.2 moles of alkanolamine per mole of metal in an alcohol solvent to form a first mixture;
- (b) contacting the first mixture with a boron compound at a mole ratio of about 0.25 to 3 moles of boron per mole of metal to produce a second mixture;
- (c) maintaining the second mixture for a sufficient period of time for the reaction to reach equilibrium;
- and (d) removing the volatiles from the product of step (c) to form a solid borometalate cross-linker.
A method for selectively plugging permeable zones and leaks in subterranean formations which comprises introducing into the permeable zone or the site of the subterranean leak, a cross-linking composition comprising (A) an aqueous liquid;
- (B) a pH buffer;
- (C) a cross-linkable organic polymer;
- and D) a solid borozirconate or borotitanate complex prepared by a process comprising (a) contacting a metal complex, wherein the metal is zirconium or titanium, with alkanolamine at a mole ratio of 0.8 to 2.2 moles of alkanolamine per mole of metal in an alcohol solvent to form a first mixture;
- (b) contacting the first mixture with a boron compound at a mole ratio of about 0.25 to 3 moles of boron per mole of metal to produce a second mixture;
- (c) maintaining the second mixture for a sufficient period of time for the reaction to reach equilibrium;
- and (d) removing the volatiles from the product of step (c) to form a solid borometalate cross-linker.
Dependencies are inferred from the claim text.