received by the International Bureau on 23 July 2018 (23.07.18)

What is claimed is:

1. A method for modifying a tubular member having a tube end, an exterior surface, an interior surface, a nominal wall thickness, a central axis, and a welded seam, wherein the welded seam forms a portion of the interior surface, the method comprising:

applying a patch of material to the interior surface, wherein the patch covers an arcuate segment of the interior surface that includes the welded seam and that extends from the tube end to an axially spaced first location; and

machining the patch such that the interior surface of the tubular member from the tube end to the axially spaced first location has a uniform inside diameter.

2. The method of claim 1 wherein the patch is machined such that, in an axial cross section of the tubular member taken between the tube end and the axially spaced first location, the wall thickness is uniform around the circumference of the tubular member.

3. The method of claim 1 wherein the material of the patch is a weld material; and

wherein applying the patch comprises welding a first layer of weld material to the interior surface, and welding a second layer of weld material to the first layer.

4. The method of claim 3 wherein, measured radially, the first layer has a thickness Tl before machining the patch, and the second layer has a thickness T2 before machining the patch; and

wherein machining the patch removes all of T2 and a portion of Tl .

5. The method of claim 1 wherein applying the patch comprises welding the patch using a heat input not greater than 50 kilo- Joules per inch of weld length.

6. The method of claim 3 wherein welding the first layer is performed at a first heat input; and

wherein welding the second layer is performed at a second heat input that differs from the first heat input.

7. The method of claim 1 wherein applying the patch is performed using a material that has a yield strength that is equal to or exceeds the yield strength of the tubular member.

8. The method of claim 7 wherein the yield strength of the material of the patch exceeds the yield strength of the tubular member by at least 6 %.

9. The method of claim 2 further comprising: blanking-in the exterior surface by machining the tubular member to taper from a minimum wall thickness adjacent the tube end to a greater thickness at a second location that is axially spaced from the tube end.

10. The method of claim 9 further comprising: machining threads on the exterior surface after blanking-in the exterior surface;

wherein the threads include a root surface; and

wherein the uniform wall thickness extends radially at least from interior surface to the root surface.

11. The method of claim 10 further comprising: securing the tubular member in a machine and, before removing the tubular member from the machine, machining the patch, blanking-in the exterior surface, and machining the threads on the exterior surface.

12. The method of claim 1 further comprising: blanking-in the interior surface by machining the tubular member to taper from a minimum wall thickness adjacent the tube end to a greater thickness at a second location that is axially spaced from the tube end; and

machining threads on the interior surface after blanking-in the interior surface.

13. The method of claim 3 wherein applying a first layer of weld material comprises applying a plurality of weld passes, each of the weld passes contacting another of the weld passes that is adjacent.

14. The method of claim 13 wherein each of the weld passes extends circumferentially and contacts another of the weld passes that is axially adjacent.

15. The method of claim 10 wherein the method further comprises: engaging threadingly the pin end of a first tubular member and a box end of a second tubular member;

wherein engaging threadingly includes forming a circumferentially extending interference fit between a non-threaded portion of the pin end and a non-threaded portion of the box end, the non-threaded portion of the pin end including a portion of the patch.

16. The method of claim 15 wherein the outside diameter of the box end is the same as the outside diameter of the first tubular member.

17. The method of claim 15 wherein the outside diameter of the box end of the second tubular member is greater than the outside diameter of the first tubular member.

18. The method of claim 17 wherein the box end comprises a forging that is welded to a non- threaded end of the second tubular member.

19. The method of claim 1 further comprising: swaging the tubular member adjacent the tube end, resulting in the tube end being expanded in diameter.

20. The method of claim 1 further comprising: swaging the tubular member adjacent the tube end, resulting in the tube end being contracted in diameter.

21. A tubular member comprising: a tube body, a tube end, an exterior surface, an interior surface, a nominal wall thickness, a longitudinal axis, a welded seam, and a patch of material; wherein the welded seam forms an arcuate portion of the interior surface;

wherein the patch covers a portion of the interior surface that includes a portion of the welded seam, and wherein the patch extends from the tube end to an axially spaced first location, and extends an axial length that is less than the length of the tube body; and

wherein the resulting interior surface from the tube end to the axially spaced first location has a uniform inside diameter.

22. The tubular member of claim 21 wherein the exterior surface of the tubular member includes threads adjacent the tube end.

23. The tubular member of claim 22 wherein the exterior surface is tapered relative to the axis, and the threads are tapered wedge threads.

24. The tubular member of claim 22 wherein exterior surface further includes a non-threaded seal surface disposed between the tube end and the threads; and

wherein the patch is axially aligned with the seal surface and at least a portion of the threads.

25. The tubular member of claim 25 wherein the patch extends beyond the seal surface and extends at least 2 inches and at most 18 inches from the tubing end.

26. The tubular member of claim 21 wherein the patch is contained within an arc length of 45 degrees or less.

27. The tubular member of claim 26 wherein the welded seam has two longitudinally extending sides; and wherein the patch extends circumferentially beyond each side of the welded seam by a distance of at least 1.5% and less than 5% of the circumference of the tubular member.

28. The tubular member of claim 21 wherein a portion of the inner surface has a nonuniform inside diameter, and this non-uniform portion is adjacent the welded seam and is axially spaced from the first tube end and is disposed beyond the first location.

29. The tubular member of claim 21 wherein the yield strength of the material of the patch exceeds the yield strength of the tubular member by at least 6 %.

30. The tubular member of claim 21 wherein the yield strength of the material of the patch is substantially equal to the yield strength of the tubular member.

31. The tubular member of claim 21 wherein the welded seam extends as a spiral along the length of the tubular member from the tube end to an opposite end of the tubular member.

32. The tubular member of claim 22 wherein the exterior surface is cylindrical relative to the axis, and the thread;

33. A tubular member comprising: a tube end, an exterior surface, an interior surface, a nominal wall thickness, a longitudinal axis, a welded seam, a patch of weld material, and a weld enhancement end location axially spaced from the tube end;

wherein the welded seam forms an arcuate portion of the interior surface;

wherein the patch covers a portion of the interior surface that includes a portion of the welded seam, and wherein the patch extends axially from the weld enhancement end location toward the tube end; and

wherein the portion of the interior surface covered by the patch has a uniform inside diameter.

34. The tubular member of claim 33 wherein the exterior surface includes threads adjacent the tube end and extending axially along a portion of the patch.

35. The tubular member of claim 33 wherein the interior surface includes threads adjacent the tube end;

wherein the weld enhancement end location is axially spaced apart from the threads; and wherein the patch extends axially from the weld enhancement end location to a second location adjacent the threads.

36. The tubular member of claim 21 wherein the modulus of elasticity of the material of the patch is within 20% of the modulus of elasticity of the tube body.