Prevention of gas hydrates formation in BOP fluids in deep water operations

1. A method for preventing formation of a gas hydrate in a BOP fluid in deep water well operations comprising the step of adding 28% to 35% by volume of an alcohol to the BOP fluid to form a nitrogen hydrate-resistant BOP fluid, wherein the BOP fluid is resistant to formation of nitrogen hydrates at a temperature of 2° C. or less and a pressure greater than 2000 psi.

2. The method of claim 1 , wherein the alcohol is selected from the group consisting of monoethylene glycol, propylene glycol, glycerol, methanol, and a mixture thereof.

3. The method of claim 1 , wherein a temperature reduction is produced in a nitrogen hydrate phase equilibrium boundary of approximately 10° C. for a given pressure.

4. The method of claim 1 , wherein the BOP fluid comprises about 5% by volume of a fluid additive and at least 65% by volume of water.

5. The method of claim 4 , wherein the additive is selected from a group consisting of one or more salts, lubricity components, mineral oils, vegetable oils, synthetic hydrocarbon oils, synthetic silicon-based oils, phospholipids, and mixtures thereof, antifreeze components, anti-corrosion components, bacterial and/or fungal growth inhibitors, elastomer compatibility components, pour point components, viscosity components, pH components, and combinations thereof.

6. The method of claim 4 , wherein the water comprises deionized water, sea water, rig potable water, and combinations thereof.

7. A method for preventing formation of a gas hydrate in BOP fluid in deep water well operations comprising:

verifying stack mounted accumulator seals on a BOP;

adding 28% to 35% by volume of an alcohol to the BOP fluid, wherein addition of the 28% to 35% by volume of alcohol inhibits nitrogen hydrate formation; and

monitoring the BOP control system to determine if a leak has occurred and initiate a countdown.

8. The method of claim 7 , further comprising replacing nitrogen with helium, neon, or argon as the accumulator working gas.

9. A hydrate-resistant BOP fluid for deep water well operations, comprising:

28% to 35% by volume of an alcohol;

at least 5% by volume of a fluid additive; and

balance of water,

wherein the BOP fluid is nitrogen hydrate resistant.

10. The hydrate-resistant BOP fluid of claim 9 , wherein the alcohol is selected from the group consisting of monoethylene glycol, propylene glycol, glycerol, methanol, and a mixture thereof.

11. The hydrate-resistant BOP fluid of claim 9 , wherein a nitrogen hydrate phase equilibrium boundary of the nitrogen hydrate-resistant BOP fluid is approximately 10° C. less for a given pressure than a nitrogen hydrate phase equilibrium boundary of a BOP fluid without 28% to 35% by volume of the alcohol.

12. The hydrate-resistant BOP fluid of claim 9 , wherein the fluid additive comprises one or more salts, lubricity components, mineral oils, vegetable oils, synthetic hydrocarbon oils, synthetic silicon-based oils, phospholipids, and mixtures thereof, antifreeze components, anti-corrosion components, bacterial and/or fungal growth inhibitors, elastomer compatibility components, pour point components, viscosity components, pH components and any combination thereof.

13. The hydrate-resistant BOP fluid of claim 9 , wherein the water comprises deionized water, sea water, rig potable water, and combinations thereof.

14. A hydrate-resistant BOP fluid for deep water well operations, consisting essentially of:

30% to 35% by volume of an alcohol;

5% by volume of a fluid additive; and

balance being water,

wherein the fluid is nitrogen hydrate resistant.

15. The hydrate-resistant BOP fluid of claim 14 , wherein the alcohol is selected from the group consisting essentially of: monoethylene glycol, propylene glycol, glycerol, methanol, and a mixture thereof.

16. The hydrate-resistant BOP fluid of claim 14 , wherein the fluid additive is selected from a group consisting essentially of: one or more salts, lubricity components, mineral oils, vegetable oils, synthetic hydrocarbon oils, synthetic silicon-based oils, phospholipids, and mixtures thereof, antifreeze components, anti-corrosion components, bacterial and/or fungal growth inhibitors, elastomer compatibility components, pour point components, viscosity components, pH components and any combination thereof.