Patent EA-000357-B1 (EA)
Title: A method of improving the properties of a veil drilling fluid, a method of improving lubricating properties of a drilling fluid for drilling, a method of reducing torque and drag when rotating, raising or lowering drill pipe, a method for controlling the drilling fluid loss from oil well downhole
Inventor: DERWIN DAVID J
IPC: E21B21/00
Filed: 1996-12-10
Abstract: 1. A method of improving the properties of a veil drilling fluid comprising the step of adding to the drilling fluid resilient graphitic carbon particles. 2. The method of Claim 1, wherein said particles have a resiliency of greater than about 35% rebound after compression at 10,000 psi. 3. The method of Claim 1, wherein said resiliency is between about 100 to 150%. 4. The method of Claim 1, wherein said particles are greater than about (+200) mesh. 5. The method of Claim 1, wherein the size range of about 90% of the graphitic carbon particles is between (-20) and (+200) mesh. 6. The method of Claim 1, wherein the graphitic carbon particles are added to the drilling fluid in concentrations between about 30 lb/bbl to 120 lb/bbl. 7. The method of Claim 1, wherein the graphitic carbon particles are present in the whole fluid system in a concentration of about 2 to 6 lb/bbl. 8. The method of Claim 1, wherein the graphitic carbon particles are made by graphitisation of petroleum coke. 9. The method of Claim 8, wherein the petroleum coke is a fluidised petroleum coke. 10. The method of Claim 8, wherein the petroleum coke is a delayed petroleum coke. 11. The method of Claim 1, wherein the graphitic carbon particles have more than about 80% graphite content. 12. The method of Claim 1, wherein the graphitic carbon particles have graphite content of about 20% or greater. 13. The method of Claim 1, wherein the graphitic carbon particles have a particle density between about 1.45 to 2.2 g/cc. 14. The method of Claim 1, wherein the drilling fluid is water based. 15. The method of Claim 1, wherein the drilling fluid is oil based. 16. The method of Claim 1, wherein said graphitic carbon particles are added to the drilling fluid in an amount sufficient to prevent loss of the drilling fluid into porous or fractured formations. 17. The method of Claim 1, wherein said graphitic carbon particles are added to the drilling fluid in an amount effective to correct loss of drilling fluid to porous or fractured formations. 18. A method of improving the lubricating properties of a drilling fluid used during the drilling of a well, comprising the step of adding a lubricant that includes resilient graphitic carbon particles ranging in size from about (+20) mesh to about 8 microns. 19. The method of Claim 18, wherein the lubricant is added in concentrations of between about 20 lb/bbl to 120 lb/bbl. 20. A method of reducing torque and drag when rotating, raising or lowering drill pipe, comprising the step of adding resilient graphitic carbon particles of about (-20) to about (+200) mesh size to drilling fluid while the fluid is being circulated. 21. A method of controlling the loss of drilling fluid from an oil well downhole comprising adding graphitic carbon particles to the downhole. 22. The method of Claim 21 wherein the graphitic carbon particles are added to a fluid. 23. The method of Claim 21 wherein the graphitic carbon particles are combined with a seepage loss additive. 24. The method of Claim 22 wherein the fluid is drilling fluid. 25. The method of Claim 22 wherein said graphitic carbon particles have a resiliency of greater than about 35% rebound after compression at 10,000 psi. 26. The method of Claim 23 wherein said graphitic carbon particles have a resiliency of greater than about 35% rebound after compression at 10,000 psi. 27. The method of Claim 22 wherein said graphitic carbon particles are greater than about (+200) mesh. 28. The method of Claim 23 wherein said graphitic carbon particles are greater than about (+200) mesh.