Claims
- 1. A base fluid comprising:
at least about 5 wt % olefins; at least about 5 wt % n-paraffins; and between about 2 and 50 wt % branched paraffins wherein substantially all of the branch groups are monomethyl and wherein the ratio of terminal monomethyl branching to internal monomethyl branching is at least about 1:1.5.
- 2. The base fluid of claim 1 wherein the ratio of terminal monomethyl branching to internal monomethyl branching is at least about 1:1.
- 3. The base fluid of claim 1 wherein the n-paraffins are present in an amount of at least about 20 wt % and wherein the ratio of terminal monomethyl branching to internal monomethyl branching is at least about 1.5:1.
- 4. The base fluid of claim 1 wherein the n-paraffins are present in an amount of at least about 40 wt % and wherein the ratio of terminal monomethyl branching to internal monomethyl is at least about 2:1.
- 5. The base fluid of claim 1 wherein the base fluid is a product of a Fischer-Tropsch reaction.
- 6. The base fluid of claim 5 wherein the Fischer-Tropsch reaction incorporates feed syngas having 10-60% N2.
- 7. A drilling fluid comprising:
the base fluid of claim 1.
- 8. The drilling fluid of claim 7 further comprising:
at least one additive selected from the group of surfactants, viscosifiers, weighting agents, fluid loss control agents and proppants.
- 9. A drilling fluid comprising:
from about 2 to about 90 wt % olefins; from about 2 to about 50 wt % isoparaffins; wherein the isoparaffins are substantially terminal monomethyl branched. from about 5 to about 90 wt % n-paraffins; and from about 0 to about 10 wt % oxygenates.
- 10. The drilling fluid of claim 9 wherein the olefins are present in an amount of from about 7 to about 10 wt %.
- 11. The drilling fluid of claim 9 wherein the isoparaffins are present in an amount of from about 3 to about 15 wt %.
- 12. The drilling fluid of claim 9 wherein the n-paraffins are present in an amount of from about 65 to about 90 wt %.
- 13. The drilling fluid of claim 9 wherein the oxygenates are present in an amount of from about 0 to about 5 wt %.
- 14. The drilling fluid of claim 9 wherein the base fluid is a product of Fischer-Tropsch reaction on a synthesis gas.
- 15. The drilling fluid of claim 14 wherein the Fischer-Tropsch reaction incorporates feed syngas having 10-60% N2.
- 16. The drilling fluid of clam 14 wherein the synthesis gas is produced by autothermal reformation.
- 17. The drilling fluid of claim 16 wherein the autothermal reformation occurs in the presence of air.
- 18. The drilling fluid of claim 16 wherein the autothermal reformation occurs in the presence of 10-60% N2.
- 19. The drilling fluid of claim 9 further comprising:
at least one additive selected from the group of surfactants, viscosifiers, weighting agents, fluid loss control agents and proppants.
- 20. The drilling fluid of claim 9 wherein the olefins are:
from about 7 to about 10 wt %; the isoparaffins are from about 2 to about 15 wt %; wherein the isoparaffins are substantially terminal monomethyl branched. The n-paraffins are from about 65 to about 90 wt %; and the oxygenates are from about 0 to about 5 wt %.
- 21. The drilling fluid of claim 20 wherein the drilling fluid is a product of a Fischer-Tropsch reaction.
- 22. The drilling fluid of claim 20 further comprising:
at least one additive selected from the group of surfactants, viscosifiers, weighting agents, fluid loss control agents and proppants.
- 23. The drilling fluid of claim 20 wherein the base fluid comprises from about 25 to about 85 volume % of the drilling fluid.
- 24. The drilling fluid of claim 23 wherein the base fluid comprises from about 25 to about 85 volume % of the drilling fluid.
- 25. The drilling fluid of claim 22 wherein the Fischer-Tropsch reaction incorporates feed syngas having 10-60% N2.
- 26. The drilling fluid of claim 23 wherein the feed syngas is produced by autothermal reformation in the presence of air.
- 27. A process for producing a drilling fluid comprising the steps of:
(a) producing a light Fischer-Tropsch liquid; (b) distilling the light Fischer-Tropsch liquid to obtain a C13-C20+ product having C13-C20+ hydrocarbons and oxygenates. (c) dehydrating all or a part of the alcohols in the C13-C20+ product by passing the C13-C20+ product over an activated alumina catalyst to produce a dehydrated product; (d) recovering the dehydrated product; and (e) separating the aqueous and organic phases of the dehydrated product.
- 28. The process of claim 27 further comprising the step of:
(f) adding one or more additive selected from the group of surfactants, viscosifiers, weighting agents, fluid loss control agents and proppants to the organic phase of the dehydrated product.
- 29. The process of claim 27 further comprising the step of (b1) vaporizing the C13-C20+ product before step (c) and after step (b).
- 30. The process of claim 29 wherein the dehydrated product from step (c) is in the gaseous state and step (d) further includes condensing the dehydrated product.
- 31. The process of claim 30 wherein the heat from condensing the dehydrated product is recycled to at least partially vaporize the C13-C20+ product in step (b1).
- 32. The process of claim 27 wherein the light Fischer-Tropsch liquid is produced from a feed syngas having 10-60% N2.
- 33. The process of claim 27 wherein the feed syngas is produced by autothermal reformation in the presence of air.
- 34. The process of claim 27 wherein a C14-C18 product is obtained in step (b) and dehydrated in step (c).
- 35. A method of drilling a borehole in a subterranean formation comprising the steps of:
(a) rotating a drill bit at the bottom of the borehole; (b) introducing a drilling fluid into the borehole wherein the drilling fluid comprises a base fluid comprising:
from about 5 to about 90 wt % olefins; from about 2 to about 50 wt % isoparaffins; wherein the isoparaffins are substantially terminal monomethyl branched; from about 5 to about 90 wt % n-paraffins; and from about 0 to about 10 wt % oxygenates.
- 36. The process of claim 35 wherein the drilling fluid comprises:
from about 7 to about 10 wt % olefins; from about 2 to about 15 wt % isoparaffins; wherein the isoparaffins are substantially terminal monomethyl branched; from about 65 to about 90 wt % n-paraffins; and from about 0 to about 5 wt % oxygenates.
- 37. The process of claim 35 wherein the base fluid is derived from a Fischer-Tropsch reaction.
- 38. The process of claim 37 wherein the Fischer-Tropsch reaction incorporates feed syngas having 10-60% N2.
- 39. The process of claim 37 wherein the feed syngas is produced by autothermal reformation in the presence of air.
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Application Serial No. 60/449,557, filed on Feb. 24, 2003.
Provisional Applications (1)
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Number |
Date |
Country |
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60449557 |
Feb 2003 |
US |