Colloidal silica and polymer system for insulating packer fluids
Insulating packer fluids containing colloidal silica inorganic additives may be used in methods that reduce convective currents in a packer fluid. In other aspects, packer fluids containing colloidal silica inorganic additives may be used in methods of insulating production wells and methods for stimulating production of hydrocarbons.
1. A method of reducing convective currents in a packer fluid, the method comprising:
pumping a packer fluid into an annulus of a wellbore created by two concentric strings of pipe extending into the wellbore, wherein the packer fluid comprises:
an aqueous base fluid,
a colloidal silica inorganic additive,
a thermal stabilizer selected from a group consisting of trimethanolamine, triethanolamine, triisopropanolamine, diethylaminopropanol, diethyl ethanolamine and dimethylamino-1-propanol, and
a polymeric viscosifier.
2. The method of claim 1 , wherein polymeric viscosifier is a polymer, copolymer, or higher order copolymer containing one or more monomers selected from a group consisting of 2-acrylamido-2-methylpropanesulfonate, acrylamide, methacrylamide, N,N dimethyl acrylamide, N,N dimethyl methacrylamide, dimethylaminopropyl methacrylamide, N-vinyl-2-pyrrolidone, N-vinyl-3-methyl-2-pyrrolidone, N-vinyl-4,4-diethyl-2-pyrrolidone, 5-isobutyl-2-pyrrolidone, N-vinyl-3-methyl-2-pyrrolidone, alkyl oxazoline, and 2-ethyl-2-oxazoline.
3. The method of claim 2 , wherein the polymeric viscosifier is a terpolymer of 2-acrylamido-2-methylpropanesulfonate, acrylamide, and 2-vinylpryrrolidone.
4. The method of claim 1 , wherein the colloidal silica inorganic additive is present in the packer fluid in a concentration ranging from about 5 wt % to about 30 wt %.
5. The method of claim 1 , wherein the colloidal silica is a surface-modified colloidal silica comprising a lipophilic coating.
6. The method of claim 5 , wherein the lipophilic coating comprises at least one of a polysiloxane, an aminoalkylsilane, and an alkoxyorganomercaptosilane.
7. A method for stimulating a well, comprising
pumping a packer fluid into an annulus a wellbore created by two concentric strings of pipe extending into the wellbore, wherein the packer fluid comprises:
an aqueous base fluid,
a colloidal silica inorganic additive,
a thermal stabilizer selected from a group consisting of trimethanolamine, triethanolamine, triisopropanolamine, diethylaminopropanol, diethyl ethanolamine and dimethylamino-1-propanol, and
a polymeric viscosifier; and
injecting hot water or steam through an interior pipe of the two concentric strings of pipe.
8. The method of claim 7 , wherein the aqueous base fluid further comprises an internal oleaginous phase, wherein the internal oleaginous phase is one or more selected from a group consisting of diesel oil, a mixture of diesel and paraffin oil, mineral oil, and isomerized olefins.
9. The method of claim 7 , wherein the d 50 particle diameter of the colloidal silica inorganic additive ranges from 9 nm to 100 nm.
10. The method of claim 7 , wherein the colloidal silica is a surface-modified colloidal silica comprising a lipophilic coating.
11. The method of claim 10 , wherein the lipophilic coating comprises at least one of a polysiloxane, an aminoalkylsilane, and an alkoxyorganomercaptosilane.
12. The method of claim 7 , wherein polymeric viscosifier is a polymer, copolymer, or higher order copolymer containing one or more monomers selected from a group consisting of 2-acrylamido-2-methylpropanesulfonate, acrylamide, methacrylamide, N,N dimethyl acrylamide, N,N dimethyl methacrylamide, dimethylaminopropyl methacrylamide, N-vinyl-2-pyrrolidone, N-vinyl-3-methyl-2-pyrrolidone, N-vinyl-4,4-diethyl-2-pyrrolidone, 5-isobutyl-2-pyrrolidone, N-vinyl-3-methyl-2-pyrrolidone, alkyl oxazoline, and 2-ethyl-2-oxazoline.
13. The method of claim 7 , wherein the polymeric viscosifier is a terpolymer of 2-acrylamido-2-methylpropanesulfonate, acrylamide, and 2-vinylpryrrolidone.
14. An insulating packer fluid, comprising:
an aqueous base fluid,
a colloidal silica inorganic additive,
a thermal stabilizer selected from a group consisting of trimethanolamine, triethanolamine, triisopropanolamine, diethylaminopropanol, diethyl ethanolamine and dimethylamino-1-propanol, and
a polymeric viscosifier.
15. The fluid of claim 14 , wherein the colloidal silica inorganic additive comprises a surface-modified silica.
16. The fluid of claim 15 , wherein the surface-modified silica comprises at least one of a polysiloxane, an aminoalkylsilane, and an alkoxyorganomercaptosilane.
17. The fluid of claim 14 , wherein the colloidal silica inorganic additive is present in the packer fluid in a concentration ranging from about 5 wt % to about 30 wt %.
18. The fluid of claim 14 , wherein polymeric viscosifier is a polymer, copolymer, block copolymer, or higher order copolymer containing one or more monomers selected from a group consisting of 2-acrylamido-2-methylpropanesulfonate, acrylamide, methacrylamide, N,N dimethyl acrylamide, N,N dimethyl methacrylamide, dimethylaminopropyl methacrylamide, N-vinyl-2-pyrrolidone, N-vinyl-3-methyl-2-pyrrolidone, N-vinyl-4,4-diethyl-2-pyrrolidone, 5-isobutyl-2-pyrrolidone, N-vinyl-3-methyl-2-pyrrolidone, alkyl oxazoline, and poly(2-ethyl-2-oxazoline).
19. The fluid of claim 18 , wherein the polymeric viscosifier is a terpolymer of 2-acrylamido-2-methylpropanesulfonate, acrylamide, and 2-vinylpryrrolidone.
20. The fluid of claim 14 , further comprising a micronized weighting agent.