Drilling fluid for downhole electrocrushing drilling
The disclosure relates to an electrocrushing drilling fluid with an electrocrushing drilling base fluid including a non-polar oil, water, and glycerin. The base fluid may further include a polar oil and an alkylene carbonate. The electrocrushing drilling fluid may further contain at least one additive. The electrocrushing drilling fluid may have a dielectric constant or dielectric strength of at least a set amount, an electric conductivity less than a set amount, or a combination of these properties. The disclosure further relates to an electrocrushing drilling system containing the electrocrushing drilling fluid and an electrocrushing drill bit.
1. An electrocrushing drilling fluid comprising an electrocrushing drilling base fluid comprising at least one of a non-polar oil, water, and glycerin, wherein the electrocrushing drilling base fluid has a dielectric constant of at least 6 at 100 kHz frequency.
2. The electrocrushing drilling fluid of claim 1 , wherein the electrocrushing drilling base fluid has a dielectric strength of at least 100 kV/cm at 10 microseconds rise time.
3. The electrocrushing drilling fluid of claim 1 , wherein the electrocrushing drilling base fluid has an electric conductivity of less than 10 −4 mho/cm.
4. The electrocrushing drilling fluid of claim 1 , wherein the electrocrushing drilling base fluid has a non-polar oil:water ratio between 75:25 and 85:15 (v:v).
5. The electrocrushing drilling fluid of claim 1 , wherein the non-polar oil comprises a mineral oil, a diesel oil or fuel, a paraffin-based oil, an oil containing branched and linear aliphatic hydrocarbons having between 8 and 26 carbon atoms and a boiling point in the range of 120° C. to 380° C., an oil containing hydrocarbons having between 10 and 16 carbon atoms and a viscosity of 1.5 to 2 cSt at 40° C., or any combinations thereof.
6. The electrocrushing drilling fluid of claim 1 , further comprising at least one additive comprising an electrical additive, a lost circulation material, a rheology modifier, a weighting agent, an emulsifier, a corrosion inhibitor, a defoamer, a shale stabilizer, a lubricant, a wetting agent, a dispersing agent, a shale inhibitor, a pH-control agent, a filtration-control agent, an alkalinity source, a foamer, a viscosifier, a thinner, a deflocculent or any combinations thereof.
7. The electrocrushing drilling fluid of claim 1 , wherein the electrocrushing drilling fluid has a dielectric constant of at least 13 at 100 kHz.
8. The electrocrushing drilling fluid of claim 1 , wherein the electrocrushing drilling fluid has a dielectric constant of at least 10 at 100 kHz.
9. The electrocrushing drilling fluid of claim 1 , wherein the electrocrushing drilling base fluid further comprises one, but not both of, a polar oil and an alkylene carbonate.