Glycols as internal phase in oil well drilling fluids

Abstract

An emulsion and emulsion drilling fluid are disclosed. The emulsion has utility as an oil based drilling fluid comprising a glycol emulsified in a synthetic hydrocarbon material. The synthetic hydrocarbon material has an average molecular weight of from about 120 to 1,000 and is synthesized from one or more olefinic monomers having a chain length of C 2 to C 14 .

What is claimed is: 
     
       1. An improved emulsion for an oil-based drilling fluid, said emulsion comprising a glycol emulsified in a synthetic hydrocarbon material, said synthetic hydrocarbon material having an average molecular weight of from about 120 to about 1000 and being synthesized from one or more olefinic monomers having a chain length of C 2  to C 14 . 
     
     
       2. The improved emulsion for an oil based drilling fluid of claim 1 wherein said synthetic hydrocarbon oil comprises branched chain oligomers synthesized from one or more clefins containing a C 2  to C 12  chain length and wherein the oligomers have an average molecular weight of from 160 to 800. 
     
     
       3. The improved emulsion for an oil based drilling fluid of claim 1 wherein said synthetic hydrocarbon oil comprises branched chain oligomers synthesized from one or more olefins containing a C 2  to C 10  chain length and wherein the oligomers have an average molecular weight of 200 to 600. 
     
     
       4. The improved emulsion for an oil based drilling fluid of claim 1 wherein the viscosity of said oil is from 1.0 to 6.0 centistokes when measured at 212° F. 
     
     
       5. The improved emulsion for an oil-based drilling fluid of claim 1 wherein said synthetic hydrocarbons are selected from the group consisting of oligomers of: ethylene, propene, butene-1, isobutene, hexene, heptene, octene, nonene, decene, dodecene and combinations thereof. 
     
     
       6. The improved emulsion for an oil based drilling fluid of claim 1 wherein said synthetic hydrocarbons is polydecene. 
     
     
       7. The improved emulsion of claim 1 wherein said glycol is selected from the group consisting of: propylene glycol, glycerine, water soluble polyol and combinations thereof. 
     
     
       8. The improved emulsion of claim 1 further including a weight material. 
     
     
       9. The improved emulsion for an oil-based drilling fluid of claim 8 wherein said weight material is selected from the group consisting of: barite, iron oxide, calcium carbonate, and combinations thereof. 
     
     
       10. A drilling fluid comprising: (a) an improved continuous phase, said continuous phase comprising a synthetic hydrocarbon oil, said synthetic hydrocarbon oil having an average molecular weight of from about 120 to about 1000 and being synthesized from one or more olefinic monomers having a chain length of C 2  to C 14  ;   (b) a glycol material emulsified in said synthetic hydrocarbon oil; and   (c) a weight material.   
     
     
       11. The drilling fluid of claim 10 wherein said drilling fluid contains up to 70% glycol by volume. 
     
     
       12. The drilling fluid of claim 10 wherein said glycol material contains up to 80% water by volume. 
     
     
       13. The drilling fluid of claim 10 including said improved continuous phase wherein said drilling fluid further contains an emulsifier. 
     
     
       14. The drilling fluid of claim 13 wherein said emulsifier is selected from the group consisting of: fatty acids, soaps of fatty acids, amido-amines, polyamides, polyamines, oleate esters, imidazolines, alcohols, polyalkylene carboxylate and combinations thereof. 
     
     
       15. The drilling fluid of claim 13 wherein said emulsifier is present at a concentration of up to 10% by weight. 
     
     
       16. The drilling fluid of claim 10 further comprising a wetting agent. 
     
     
       17. The drilling fluid of claim 16 wherein said wetting agent is selected from the group consisting of: crude tall oil, oxidized crude tall oil, organic phosphate esters, imidazolines, alkyl aromatic sulfonates and combinations thereof. 
     
     
       18. The drilling fluid of claim 10 further comprising a viscosifier. 
     
     
       19. The drilling fluid of claim 18 wherein said viscosifier is selected from the group consisting of: organophilic clays, oil soluble polymers, polycarboxylic acid, soaps and combinations thereof. 
     
     
       20. The drilling fluid of claim 10 wherein said weight material is selected from the group consisting of: barite, iron oxide, calcium carbonate and combinations thereof. 
     
     
       21. The drilling fluid of claim 10 wherein said glycol is selected from the group consisting of: propylene glycol, glycerine, water soluble polyol and combinations thereof. 
     
     
       22. A drilling fluid, said drilling fluid including an improved continuous phase, said drilling fluid comprising: (a) a continuous phase comprising a synthetic hydrocarbon, said synthetic hydrocarbon having an average molecular weight of from about 120 to about 1000 and being synthesized from one or more olefinic monomers having a chain length of C 2  to C 14  ;   (b) a glycol-in-oil emulsifier;   (c) a glycol emulsified in said synthetic hydrocarbon oil;   (d) an aqueous phase, said aqueous phase comprising up to about 80% of glycol by volume; and   (e) a weight material.