Polymer crosslinking system
AssigneeSchlumberger Technology Corporation
InventorGreig Fraser
Life of this patent
Estimating the term…
Abstract
A composition useful for making gelled fluids by crosslinking hydratable polymers is an aqueous solution of zirconium complexed with carbonate and bicarbonate as the only multidentate ligands complexed with zirconium. The composition also provides pH modifying capability and the crosslinking is delayed, so that the single composition replaces several liquid additives previously necessary for generation of fluids used, for example, in hydraulic fracturing.
Claims21
A fluid composition comprising water, carbonate in solution, bicarbonate in solution, and soluble zirconium(IV) having carbonate and bicarbonate as the only carbon-containing multidentate ligands complexed with zirconium.
A method of fracturing a subterranean formation penetrated by a wellbore comprising:
- a. providing a first fluid comprising water and a hydratable polymer crosslinkable with zirconium;
- b. providing a second fluid comprising water, carbonate in solution, bicarbonate in solution, and soluble zirconium(IV) having carbonate and bicarbonate as the only carbon-containing ligands complexed with zirconium;
- c. mixing said first and second fluids to form a mixed fluid;
- and
- d. injecting said mixed fluid into said formation.
A method of forming a gelled fluid comprising mixing
- a. a first fluid comprising water and a hydratable polymer crosslinkable with zirconium, and
- b. a second fluid comprising water, carbonate in solution, bicarbonate in solution, and soluble zirconium(IV) having carbonate and bicarbonate as the only carbon-containing ligands complexed with zirconium.
Dependencies are inferred from the claim text.