High temperature seawater-based cross-linked fracturing fluids and methods
AssigneeHalliburton Energy Services, Inc.
InventorsPaul D. Lord, John Terracina, Billy Slabaugh
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Abstract
The present invention provides seawater-based cross-linked fracturing fluids and methods of preparing and using the fluids in fracturing subterranean formations penetrated by well bores and having temperatures above about 200° F. The improved cross-linked fracturing fluids are basically comprised of a gelling agent, seawater present in an amount sufficient to hydrate the gelling agent and to form a gelled aqueous fluid, and a delayed cross-linking agent, capable of causing delayed cross-linking of the gelling agent in the gelled aqueous fluid at a pH below the threshold for precipitate formation in seawater.
Claims16
A method of fracturing a subterranean formation penetrated by an offshore well bore and having a temperature above about 200° F., comprising the steps of:
- (a) preparing a seawater-based delayed cross-linked fracturing fluid comprising:
- a gelling agent;
- seawater, present in an amount sufficient to hydrate said gelling agent, thereby forming a gelled aqueous fluid;
- and
- a delayed cross-linking agent capable of causing delayed cross-linking of said gelling agent at a pH of about 9.5 or less, whereby said delay is about 5 minutes or more;
- and
- (b) introducing said fracturing fluid into the subterranean formation at a rate and pressure whereby fractures are formed in the subterranean formation.
A method of fracturing a subterranean formation penetrated by a well bore and having a temperature above about 200° F., comprising the steps of:
- (a) preparing delayed cross-linked fracturing fluid comprising:
- a gelling agent;
- seawater present in an amount sufficient to hydrate said gelling agent;
- and
- a delayed cross-linking agent, said cross-linking agent being selected from the group consisting of ammonium titanyl citrate, ammonium titanyl tartarate, ammonium titanyl gluconate, and mixtures thereof;
- and
- (b) introducing said fracturing fluid into the subterranean formation at a rate and pressure whereby fractures are formed in the subterranean formation.
Dependencies are inferred from the claim text.