IP Library Granted Patent US 7,395,863
Granted Patent B2
US 7,395,863 · App. 11/953,645 · Granted Jul 8, 2008

Method of treating a subterranean formation with an oil-based composition containing a polysaccharide-based water-superabsorbent material

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Quick Facts
Patent No.
US 7,395,863
App. No.
11/953,645
Granted
Jul 8, 2008
Kind
B2
Abstract

A well treating composition containing a polysaccharide-based water-superabsorbent material has particularly applicability as a thermal insulating, fracturing or acid stimulation fluid. The water-superabsorbent material is capable of absorbing, at a minimum, its own weight. Particularly effective are biodegradable materials containing guar gum and carrageenan. The composition may further contain a crosslinking agent, brine and/or a viscosifying polymer or a gelling agent. As an oil-based fluid, the crosslinking agent is absorbed onto the water-superabsorbent material and serves to effectively delay crosslinking.

Claims (21)

1. A method for enhancing the productivity of a formation comprising introducing into the formation an oil-based composition comprising a polysaccharide-based water-superabsorbent material, a crosslinking agent absorbed onto the superabsorbent material and a gelling agent.

2. The method of claim 1 , wherein the composition further comprises a proppant.

3. The method of claim 1 , wherein the composition is an acid stimulation fluid.

4. The method of claim 1 , wherein the superabsorbent material is made from guar gum and carrageenan.

5. The method of claim 1 , wherein the gelling agent is an alkyl phosphate ester.

6. The method of claim 5 , wherein the alkyl phosphate ester is a alkyl diester acid.

7. The method of claim 5 , wherein the alkyl phosphate ester is prepared by reacting a C 3-18 aliphatic alcohol with phosphorous pentoxide.

8. The method of claim 1 , wherein the water-superabsorbent material is capable of absorbing a minimum of its own weight in water.

9. The method of claim 1 , wherein the viscosity of the composition is such so as to render the composition pumpable.

10. The method of claim 1 , wherein the water-superabsorbent material is present in an amount ranging from about 0.05% to about 30% by weight, relative to the total weight of the composition.

11. The method of claim 1 , wherein the crosslinking agent is an aluminum or ferric crosslinking agent.

12. The method of claim 11 , wherein the crosslinking agent contains Fe (II) or Fe (III) or a complex which is capable of releasing Fe (II) or Fe (III).

13. A method of fracturing a subterranean formation comprising introducing into the formation for a time and at a pressure sufficient to fracture the formation a pumpable oil-based composition comprising a polysaccharide-based water-superabsorbent material, a crosslinking agent absorbed onto the superabsorbent material and a gelling agent.

14. The method of claim 13 , wherein the viscosity of the oil-based composition is sufficient to suspend and carry proppant into the formation.

15. The method of claim 13 , wherein the superabsorbent material is made from guar gum and carrageenan.

16. The method of claim 13 , wherein the gelling agent is an alkyl phosphate ester.

17. The method of claim 16 , wherein the alkyl phosphate ester is a C 3-18 alkyl diester acid.

18. The method of claim 13 , wherein the superabsorbent material is capable of absorbing a minimum of its own weight in water.

19. The method of claim 13 , wherein the at least one water-superabsorbent material is present in an amount ranging from about 0.05% to about 30% by weight, relative to the total weight of the composition.

20. The method of claim 13 , wherein the crosslinking agent is an aluminum or ferric crosslinking agent.

21. The method of claim 20 , wherein the crosslinking agent contains Fe (II) or Fe (III) or a complex which is capable of releasing Fe (II) or Fe (III).