Viscous settable fluid for lost circulation in subterranean formations
A method of treating a well the method including the steps of: (A) forming a fluid including: (i) a shear-thinning aqueous liquid phase; and (ii) an inorganic setting material; wherein the fluid is shear-thinning, pumpable, and settable; and (B) introducing the fluid into the well.
1. A method of treating a well, the method comprising the steps of:
(A) forming a fluid comprising:
(i) a shear-thinning aqueous liquid phase, wherein the shear-thinning aqueous liquid phase comprises a nano-particulate dispersed therein;
(ii) an inorganic setting material; and
(iii) a water-soluble chemical activator selected from the group consisting of: (a) phytic acid, an alkali metal salt or ammonium salt thereof; (b) methylglycinediacetic acid, an alkali metal salt or ammonium salt thereof; (c) a water-soluble polyepoxysuccinic acid, an alkali metal salt or ammonium salt thereof; and (d) salicylic acid, ascorbic acid, tannic acid, and an alkali metal salt or ammonium salt of any of the foregoing;
wherein the fluid is shear-thinning, pumpable, and settable; and
(B) introducing the fluid into the well.
2. The method according to claim 1 , wherein the fluid forms a solid within at most 0.5 hours at a temperature as least as high as a design temperature for the method.
3. The method according to claim 1 , wherein the shear-thinning aqueous liquid phase comprises a viscosity-increasing agent, and a crosslinking agent.
4. The method according to claim 3 , wherein the viscosity-increasing agent is selected from the group consisting of: a water-soluble polysaccharide, a water-soluble polysaccharide derivative, and any combination thereof.
5. The method according to claim 4 , wherein the viscosity-increasing agent comprises a guar derivative.
6. The method according to claim 4 , wherein the cross-linking agent is a borate compound.
7. The method according to claim 3 , wherein the shear-thinning aqueous liquid phase has a pH greater than 8.
8. The method according to claim 3 , wherein the shear-thinning aqueous liquid phase comprises a water-soluble inorganic salt.
9. The method according to claim 1 , wherein the nano-particulate comprises a silica.
10. The method according to claim 9 , wherein the shear-thinning aqueous liquid phase has a pH greater than 8.
11. The method according to claim 9 , wherein the shear-thinning aqueous liquid phase comprises a water-soluble inorganic salt.
12. The method according to claim 9 , wherein the shear-thinning aqueous liquid phase has an ionic strength less than 0.75.
13. The method according to claim 1 , wherein the inorganic setting material comprises a non-hydraulic cement.
14. The method according to claim 1 , wherein the inorganic setting material is selected from the group consisting of: calcium sulfate, a water-soluble silicate, and any combination thereof.
15. The method according to claim 1 , additionally comprising a lost-circulation material.
16. The method according to claim 15 , wherein the lost-circulation material is selected from the group consisting of: marble, calcium carbonate, calcium magnesium carbonate, walnut shells, graphites, fibers, cellulosic materials, and any combination thereof.
17. The method according to claim 15 , wherein the lost-circulation material has a particulate size of at least 5 microns.
18. The method according to claim 1 , wherein the fluid does not include fibers.
19. The method according to claim 1 , wherein the fluid is introduced into a zone of the well from which there is greater than 100 barrels per hour lost circulation or no return.
20. The method according to claim 1 , wherein the fluid is introduced into the well during drilling without tripping out a drill string.
21. The method according to claim 1 , wherein the fluid is introduced through a drill string or bottom hole assembly.
22. The method according to claim 1 , wherein the fluid is introduced into the well without simultaneously introducing another fluid into the well.
23. The method according to claim 1 , wherein the shear-thinning aqueous liquid phase has at least 25% by weight of the nano-particulate dispersed therein.
24. The method according to claim 1 , wherein the inorganic setting material comprises a water-soluble silicate.
25. The method according to claim 1 , wherein the inorganic setting material comprises calcium sulfate.
26. method according to claim 1 , wherein the shear-thinning aqueous liquid phase has at least 7.5% by weight of the nano-particulate dispersed therein.