Invert emulsions having a non-aqueous based internal phase containing dissolved salts
A method of drilling and completing a wellbore in a subterranean formation comprises circulating an invert oil emulsion fluid in the subterranean formation; the invert oil emulsion fluid comprising an oil phase, an emulsifier, and an internal phase comprising an alcohol other than a polycyclicpolyetherpolyol with molecular weight in excess of 50,000 and a salt dissolved in the alcohol, wherein the alcohol and the salt are selected such that the salt has a solubility in the alcohol of greater than about 3 g/100 ml at 23° C.
1. A method of drilling a wellbore in a subterranean formation, the method comprising:
circulating an invert oil emulsion drilling fluid in the subterranean formation, the invert oil emulsion drilling fluid comprising:
an oil phase;
an emulsifier; and
an internal phase comprising an alcohol other than a polycyclicpolyetherpolyol with molecular weight in excess of 50,000 Daltons and a salt dissolved in the alcohol,
wherein the alcohol and the salt are selected such that the salt has a solubility in the alcohol of greater than about 3 g/100 ml at 23° C., and
the invert emulsion comprises less than about 20 vol. % of weighting solids while achieving a density of 12 lb/gal to 18 lb/gal.
2. The method of claim 1 , wherein the salt comprises alkali halides, alkaline earth halides, alkali nitrates, alkaline earth nitrates, alkali formates, alkali acetate, alkali phosphates, zinc halides, rare earth halides, rare earth nitrates, or a combination comprising at least one of the foregoing.
3. The method of claim 1 , wherein the alcohol comprises a C 1-20 aliphatic alcohol having from 1 to 6 hydroxy groups, a C 5-20 aromatic alcohol having 1 to 6 hydroxy groups, an oligomer or polymer of the C 1-20 aliphatic alcohol, an oligomer or polymer of the C 5-20 aromatic alcohol, a cyclicetherpolyol, or a combination comprising at least one of the foregoing.
4. The method of claim 1 , wherein the alcohol comprises glycol, monoethanolamine, methyl alcohol, n-propyl alcohol, n-butyl alcohol, n-amyl alcohol, iso-amyl alcohol, benzyl alcohol, or a combination comprising at least one of the foregoing.
5. The method of claim 1 , wherein the salt is present in an amount of about 3 wt. % to about 75 wt. % of based on the total weight of the internal phase of the drilling fluid.
6. The method of claim 1 , wherein the internal phase is free of water.
7. A method of forming a gravel pack, the method comprising:
introducing into the formation a gravel pack fluid comprising
an invert emulsion and a gravel,
the invert emulsion comprising:
an oil phase;
an emulsifier; and
an internal phase comprising an alcohol other than a polycyclicpolyetherpolyol with molecular weight in excess of 50,000 Daltons and a salt dissolved in the alcohol, the alcohol and the salt being selected such that the salt has a solubility in the alcohol of greater than about 3 g/100 ml at 23° C.; and
placing the gravel adjacent the subterranean formation to form a fluid-permeable pack capable of reducing or substantially preventing the passage of formation fines from the subterranean formation into a wellbore while allowing passage of formation fluids from the subterranean formation into the wellbore,
wherein the invert emulsion comprises less than about 20 vol. % of weighting solids while achieving a density of 12 lb/gal to 18 lb/g.
8. The method of claim 7 , wherein the salt comprises alkali halides, alkaline earth halides, alkali nitrates, alkaline earth nitrates, alkali formates, alkali acetate, alkali phosphates, zinc halides, rare earth halides, rare earth nitrates, or a combination comprising at least one of the foregoing.
9. The method of claim 7 , wherein the alcohol comprises a C 1-20 aliphatic alcohol having from 1 to 6 hydroxy groups, a C 5-20 aromatic alcohol having 1 to 6 hydroxy groups, an oligomer or polymer of the C 1-20 aliphatic alcohol, an oligomer or polymer of the C 5-20 aromatic alcohol, a cyclicetherpolyol, or a combination comprising at least one of the foregoing.
10. The method of claim 7 , wherein the alcohol comprises glycol, monoethanolamine, methyl alcohol, n-propyl alcohol, n-butyl alcohol, n-amyl alcohol, iso-amyl alcohol, benzyl alcohol, or a combination comprising at least one of the foregoing.
11. The method of claim 7 , wherein the salt is present in an amount of about 3 wt. % to about 75 wt. % of based on the total weight of the internal phase of the invert emulsion.
12. An invert oil emulsion wellbore fluid comprising:
an oil phase;
an emulsifier; and
an internal phase comprising an alcohol and a salt dissolved in the alcohol,
wherein the alcohol other than a polycyclicpolyetherpolyol with molecular weight in excess of 50,000 Daltons and the alcohol and the salt are selected such that the salt has a solubility in the alcohol of greater than about 3 g/100 ml at 23° C., and
the wellbore fluid is a drilling fluid or a gravel pack fluid,
wherein the invert emulsion comprises less than about 20 vol. % of weighting solids while achieving a density of 12 lb/gal to 18 lb/gal.
13. The invert oil emulsion wellbore fluid of claim 12 , wherein the salt comprises alkali halides, alkaline earth halides, alkali nitrates, alkaline earth nitrates, alkali formates, alkali acetate, alkali phosphates, zinc halides, rare earth halides, rare earth nitrates, or a combination comprising at least one of the foregoing.
14. The invert oil emulsion wellbore fluid of claim 13 , wherein the alcohol comprises glycol, monoethanolamine, methyl alcohol, n-propyl alcohol, n-butyl alcohol, n-amyl alcohol, iso-amyl alcohol, benzyl alcohol, or a combination comprising at least one of the foregoing.
15. The invert oil emulsion wellbore fluid of claim 13 , wherein the wellbore fluid is a drilling fluid.
16. The invert oil emulsion wellbore fluid of claim 13 , wherein the wellbore fluid is a gravel pack fluid, and the wellbore fluid further comprises gravel.
17. The invert oil emulsion wellbore fluid of claim 13 , wherein the salt is present in an amount of about 3 wt. % to about 75 wt. % of based on the total weight of the internal phase of the invert oil emulsion wellbore fluid.
18. The invert oil emulsion wellbore fluid of claim 12 , wherein the alcohol comprises glycol, monoethanolamine, n-propyl alcohol, n-butyl alcohol, n-amyl alcohol, iso-amyl alcohol, benzyl alcohol, or a combination comprising at least one of the foregoing.
19. The invert oil emulsion wellbore fluid of claim 12 , wherein the salt comprises alkali nitrates, alkaline earth nitrates, alkali phosphates, zinc halides, rare earth halides, rare earth nitrates, or a combination comprising at least one of the foregoing.
20. The invert oil emulsion wellbore fluid of claim 12 , wherein the salt comprises sodium phosphate, potassium phosphate, or a combination comprising at least one of the foregoing.
21. The invert oil emulsion wellbore fluid of claim 12 , wherein the alcohol and the salt are selected such that the salt has a solubility in the alcohol of greater than about 10 g/100 ml at 23° C.
22. The invert oil emulsion wellbore fluid of claim 12 , wherein the alcohol and the salt are selected such that the salt has a solubility in the alcohol of greater than about 15 g/100 ml at 23° C.