Binding composition for proppant
A downhole treatment fluid made up of a binding composition and a proppant, the binding composition including an aluminosilicate source, a metal silicate, an alkali metal activator. The binding composition may form a coated particulate or an aggregate with the proppant and provides strength-enhancing properties. The binding composition has easy handling properties facilitating on-the-fly preparation and downhole injection procedures. Furthermore, the binding composition has a low strength-hardening temperature and so may strength-harden in the presence of downhole temperatures.
1. A method comprising:
forming a curable binding composition comprising an aluminosilicate, a metal silicate, an aqueous base fluid, and an alkali metal activator;
spraying the curable binding composition onto a proppant to form an uncured coated aggregate;
dispersing the uncured coated aggregate in a treatment fluid to form a slurry;
pumping the slurry into a borehole, wherein the borehole has at least one fracture extending from the borehole into a subterranean formation, wherein the uncured coated aggregate in the slurry cures upon exposure to downhole temperatures within the subterranean formation thereby forming a cured hardened aggregate.
2. The method of claim 1 wherein the slurry coats the proppant to form a coated proppant particulate upon strength-hardening.
3. The method of claim 1 , wherein the slurry forms an aggregate with the proppant.
4. The method of claim 1 , wherein the cured coated proppant withstands at least 8,000 psi closure pressure.
5. The method of claim 1 , wherein the aluminosilicate source is fly ash.
6. The method of claim 1 , wherein the cured coated proppant has a strength-hardening temperature of less than 400° F.
7. The method of claim 1 , wherein the aluminosilicate source has an average particle size of less than 100 microns.
8. The method of claim 1 , wherein the metal silicate is sodium metasilicate.
9. The method of claim 1 , wherein alkali metal activator contains a metal selected from groups 1 or 2 of the periodic table.
10. The method of claim 1 , wherein the alkali metal activator is an alkali metal hydroxide.
11. The method of claim 1 , alkali metal activator is selected from the group of KOH, NaOH, Ca(OH) 2 , KF, NaF, and mixtures thereof.
12. The method of claim 1 , wherein the alkali metal activator is selected from KOH or Ca(OH) 2 , and mixtures thereof.
13. The method of claim 1 , wherein the proppant is different than the aluminosilicate source.
14. The method of claim 13 , wherein the treatment fluid is injected downhole using one or more pumps.
15. The method of claim 1 , wherein the aluminosilicate, metal silicate and the alkali metal activator initiate a geopolymer formation in the slurry.
16. The method of claim 1 , alkali metal activator is selected from the group of KOH, NaOH, Ca(OH)2, KF, NaF, and mixtures thereof.
17. The method of claim 1 , wherein the cured hardened aggregate is operable to withstand at least 8,000 psi while maintaining conductivity, and fractures and pores open.
18. The method of claim 1 , wherein the spraying of the curable binding composition onto the proppant includes controlling an amount of the curable binding composition so as to form a shell around the proppant.
19. The method of claim 1 , wherein the spraying the curable binding composition onto a proppant is performed prior to being disposed in the borehole.
20. The method of claim 1 , wherein the proppant includes sand.