Methods for diversion and controlling fluid-loss using formate brine compositions

1. A method of diverting a stimulation fluid over a zone or from one zone to another zone in a subterranean formation, comprising:

introducing a treatment fluid consisting of a formate brine, xanthan gum, and a cross-linking agent into the formation;

allowing the treatment fluid to set into a gel in perforations in a first zone of the formation to block the perforations in the first zone;

introducing a stimulation fluid into the formation; and

diverting the stimulation fluid away from the perforations in the first zone to perforations in a second zone of the formation.

2. The method of claim 1 , wherein the first zone comprises a high permeability zone and the second zone comprises a low permeability zone.

3. The method of claim 1 , further comprising perforating a casing to form the perforations in the first zone or the second zone.

4. The method of claim 1 , further comprising introducing an acid into the formation.

5. The method of claim 4 , further comprising allowing the acid to degrade the gel in the perforations in the first zone.

6. The method of claim 4 , wherein the acid comprises hydrochloric acid.

7. The method of claim 1 , wherein a pump is used to introduce the treatment fluid into the formation.

8. The method of claim 1 , wherein the treatment fluid consists of:

about 1 weight percent to about 78 weight percent of a formate salt;

about 1 weight percent to about 3 weight percent of the xanthan gum; and

about 0.3 weight percent to about 1 weight percent of the cross-linking agent.

9. The method of claim 1 , wherein the formate brine comprises one or more of sodium formate, potassium formate, or cesium formate.

10. The method of claim 1 , wherein the cross-linking agent comprises a borate cross-linking compound.

11. The method of claim 10 , wherein the borate cross-linking compound comprises boric acid.

12. The method of claim 1 , wherein the formate brine comprises potassium formate and the cross-linking agent comprises boric acid.

13. A method of controlling fluid-loss in a subterranean formation comprising:

perforating a casing to form perforations;

introducing a treatment fluid into the formation after the casing is perforated or before gravel packing, wherein the treatment fluid consists of a formate brine, xanthan gum, a cross-linking agent, and a powdered sand;

allowing the treatment fluid to set into a gel in the perforations to reduce fluid-loss through the perforations; and

introducing a stimulation fluid or a gravel pack slurry into the formation.

14. The method of claim 13 , further comprising introducing the treatment fluid after introducing the gravel pack slurry.

15. The method of claim 13 , further comprising introducing an acid into the formation.

16. The method of claim 15 , further comprising allowing the acid to degrade the gel in the perforations.

17. The method of claim 13 , wherein the treatment fluid consists of:

about 1 weight percent to about 78 weight percent of a formate salt;

about 1 weight percent to about 78 weight percent of the xanthan gum;

about 0.4 weight percent to about 0.6 weight percent of the cross-linking agent; and

about 5 weight percent to about 15 weight percent of the powdered sand.

18. The method of claim 13 , wherein the formate brine comprises one or more of sodium formate, potassium formate, or cesium formate.

19. The method of claim 13 , wherein the cross-linking agent comprises a borate cross-linking compound.

20. The method of claim 13 , wherein the formate brine comprises potassium formate and the cross-linking agent comprises boric acid.