Galling resistant drill pipe tool joint and corresponding drill pipe
Disclosed herein are embodiments of a drill pipe tool joint and a drill pipe which are optimized for repeated make-up/break-out operations without the use of screw grease. Embodiments of the disclosure are environment friendly as well as having improved operating efficiency. In particular, the box and pin can be formed from different materials having different hardness.
1. A dope-free drill pipe tool joint comprising:
a pin including a male threaded portion at an outer surface; and
a box including a female threaded portion at an inner surface, the female threaded portion to be screwed and fastened to the male threaded portion in a contacting zone consisting of a male threaded contacting surface and a female threaded contacting surface;
wherein at least a portion of the male threaded contacting surface or a portion of the female threaded contacting surface is a surface layer consisting of a hard metal and respectively at least a portion of the female threaded contacting surface or a portion of the male threaded contacting surface is a surface layer consisting of a soft material and where said both surface portions are contacting surfaces after screwing;
wherein the drill pipe tool joint is dope free;
wherein a hardness ratio of the hard metal to the soft material is equal or greater than 2.8; and
wherein the hardness ratio allows the pin and the box to be made up and broken out at least 25 times without any occurrence of galling.
2. The drill pipe tool joint of claim 1 , wherein the male threaded contacting surface or the female threaded contacting surface is a surface layer consisting of a hard metal and respectively the female threaded contacting surface or the male threaded contacting surface is a surface layer consisting of a soft material.
3. The drill pipe tool joint of claim 1 , wherein the hardness of the hard metal is equal or greater than 600 Hv.
4. The drill pipe tool joint of claim 1 , wherein the hardness of the soft material is equal or lower than 350 Hv.
5. The drill pipe tool joint of claim 1 , wherein the hard metal substantially consists of a metal chosen within the list consisting of chromium (Cr), nickel (Ni), or their mixture.
6. The drill pipe tool joint of claim 5 , wherein the layer of hard metal is obtained through a plating process.
7. The drill pipe tool joint of claim 1 wherein the thickness of the layer of hard metal is comprised between 5 to 100 μm.
8. The drill pipe tool joint of claim 1 , wherein the layer of soft material is obtained through a plating process.
9. The drill pipe tool joint of claim 1 wherein the thickness of the layer of soft material is comprised between 5 to 100 μm.
10. A method of assembling the drill pipe tool joint of claim 1 , wherein the pin including the male threaded portion and the box including the female threaded portion are devoid of dope or of lubricant grease during make-up.
11. The drill pipe tool joint of claim 1 , wherein the hardness ratio is between 2.8 and 10.
12. The drill pipe tool joint of claim 1 , wherein the hardness ratio allows the pin and the box to be made up and broken out at least 50 times without any occurrence of galling.
13. The drill pipe tool joint of claim 1 , wherein the soft material consists of a metal chosen within the list consisting of copper (Cu), zinc (Zn), or their mixture.
14. The drill pipe tool joint of claim 1 , wherein the soft material substantially consists of a phosphate layer.
15. A dope-free drill pipe comprising:
a pipe body; and
a pin including a male threaded portion at an outer surface; and
a box including a female threaded portion at an inner surface, the female threaded portion to be screwed and fastened to a male threaded portion of another drill pipe of the same kind, in a contacting zone consisting of a male threaded contacting surface and a female threaded contacting surface;
wherein at least a portion of the male threaded contacting surface or a portion of the female threaded contacting surface is a surface layer consisting of a hard metal and respectively at least a portion of the female threaded contacting surface or a portion of the male threaded contacting surface is a surface layer consisting of a soft material and where said both surface portions are contacting surfaces after screwing;
wherein the drill pipe is dope free;
wherein a hardness ratio of the hard metal to the soft material is equal or greater than 2.8; and
wherein the hardness ratio allows the pin and the box to be made up and broken out at least 25 times without any occurrence of galling.
16. The drill pipe of claim 15 , wherein the male threaded contacting surface or the female threaded contacting surface is a surface layer consisting of a hard metal and respectively the female threaded contacting surface or the male threaded contacting surface is a surface layer consisting of a soft material.
17. The drill pipe of claim 15 , wherein the hardness of the hard metal is equal or greater than 600 Hv.
18. The drill pipe of claim 15 , wherein the hardness of the soft material is equal or lower than 350 Hv.
19. The drill pipe of claim 15 , wherein the hard metal substantially consists of a metal chosen within the list consisting of chromium (Cr), nickel (Ni), or their mixture.
20. The drill pipe of claim 19 , wherein the layer of hard metal is obtained through a plating process.
21. The drill pipe of claim 15 , wherein the thickness of the layer of hard metal is comprised between 5 to 100 μm.
22. The drill pipe of claim 15 , wherein the layer of soft material is obtained through a plating process.
23. The drill pipe of claim 15 , wherein the thickness of the layer of soft material is comprised between 5 to 100 μm.
24. A method of assembling the drill pipe of claim 15 , wherein the pin including the male threaded portion and the box including the female threaded portion are devoid of dope or of lubricant grease during make-up.
25. The drill pipe of claim 15 , wherein the hardness ratio is between 2.8 and 10.
26. The drill pipe of claim 15 , wherein the hardness ratio allows the pin and the box to be made up and broken out at least 50 times without any occurrence of galling.
27. The drill pipe of claim 15 , wherein the soft material consists of a metal chosen within the list consisting of copper (Cu), zinc (Zn), or their mixture.
28. The drill pipe of claim 15 , wherein the soft material substantially consists of a phosphate layer.
29. A dope-free drill pipe tool joint comprising:
a pin including a male threaded portion at an outer surface; and
a box including a female threaded portion at an inner surface, the female threaded portion configured to be screwed and fastened to the male threaded portion in a contacting zone consisting of a male threaded contacting surface and a female threaded contacting surface;
wherein at least a portion of the male threaded contacting surface or a portion of the female threaded contacting surface is a surface layer consisting of a hard metal and respectively at least a portion of the female threaded contacting surface or a portion of the male threaded contacting surface is a surface layer consisting of a soft material and where said both surface portions are contacting surfaces after screwing;
wherein the drill pipe tool joint is dope free; and
wherein a hardness ratio of the hard metal to the soft material is between 2.8 and 10.
30. A dope-free drill pipe comprising:
a pipe body; and
a pin including a male threaded portion at an outer surface; and
a box including a female threaded portion at an inner surface, the female threaded portion to be screwed and fastened to a male threaded portion of another drill pipe of the same kind, in a contacting zone consisting of a male threaded contacting surface and a female threaded contacting surface;
wherein at least a portion of the male threaded contacting surface or a portion of the female threaded contacting surface is a surface layer consisting of a hard metal and respectively at least a portion of the female threaded contacting surface or a portion of the male threaded contacting surface is a surface layer consisting of a soft material and where said both surface portions are contacting surfaces after screwing;
wherein the drill pipe is dope free; and
wherein a hardness ratio of the hard metal to the soft material is between 2.8 and 10.