TECHNICAL FIELD
[0001]
The present disclosure relates to an oil-well metal pipe and method for
producing an oil-well metal pipe.
BACKGROUND ART
[0002]
An oil-well metal pipe is used for drilling in oil fields and natural gas fields
(hereinafter, oil fields and natural gas fields are collectively referred to as "oil
wells"). An oil-well metal pipe has a threaded connection. Specifically, at the oil
well drilling site, a plurality of oil-well metal pipes are connected to form an oil
country tubular goods connected body as typified by a casing pipe or a tubing pipe.
An oil country tubular goods connected body is formed by fastening oil-well metal
pipes to each other. Inspections are sometimes conducted on oil country tubular
goods connected bodies. When conducting an inspection, the oil country tubular
goods connected body is lifted up and loosened. Oil-well metal pipes are then
detached from the oil country tubular goods connected body by loosening, and
inspected. After the inspection, the oil-well metal pipes are refastened to each
other, and the oil-well metal pipes are reused as a part of the oil country tubular
goods connected body.
[0003]
An oil-well metal pipe includes a pin and a box. The pin has a pin contact
surface including an external thread part on an outer peripheral surface of an end
portion of the oil-well metal pipe. The box has a box contact surface including an
internal thread part on an inner peripheral surface of an end portion of the oil-well
metal pipe. In the present description, the external thread part and the internal
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thread part may also be collectively referred to as "thread parts". Note that, in some
cases the pin contact surface may also include a pin unthreaded metal contact portion
including a pin sealing surface and a pin shoulder surface. Likewise, in some cases
the box contact surface may also include a box unthreaded metal contact portion
including a box sealing surface and a box shoulder surface.
[0004]
The pin contact surface and the box contact surface repeatedly experience
strong friction during fastening and loosening of the oil-well metal pipe. Therefore,
galling (unrepairable galling) is liable to occur at the pin contact surface and the box
contact surface during repeated fastening and loosening. Accordingly, an oil-well
metal pipe is required to have sufficient durability with respect to friction, that is, to
have excellent galling resistance.
[0005]
Heretofore, heavy metal powder-containing compound greases, which are
referred to as "dopes", have been used to improve the galling resistance of an oil-well
metal pipe. Application of a compound grease to the pin contact surface and/or the
box contact surface can improve the galling resistance of an oil-well metal pipe.
However, heavy metal powder contained in compound greases, such as Pb, Zn and
Cu, may affect the environment. For this reason, the development of an oil-well
metal pipe that is excellent in galling resistance even without the use of a compound
grease is desired.

We claim:
1. An oil-well metal pipe, comprising:
a pipe main body including a first end portion and a second end portion;
wherein:
the pipe main body includes:
a pin formed at the first end portion, and
a box formed at the second end portion;
the pin includes:
a pin contact surface including an external thread part;
the box includes:
a box contact surface including an internal thread part;
the oil-well metal pipe further comprising:
a resin coating containing a resin, a solid lubricant powder and copper
phthalocyanine on or above at least one of the pin contact surface and the box contact
surface.
2. The oil-well metal pipe according to claim 1, wherein:
the resin coating contains 0.2 to 30.0 mass% of copper phthalocyanine.
3. The oil-well metal pipe according to claim 2, wherein:
the resin coating contains:
0.2 to 30.0 mass% of copper phthalocyanine,
60 to 90 mass% of the resin, and
1 to 30 mass% of the solid lubricant powder.
4. The oil-well metal pipe according to claim 2 or claim 3, wherein:
the resin coating contains 0.2 to 9.0 mass% of copper phthalocyanine.
5. The oil-well metal pipe according to any one of claims 1 to 4, further
comprising:
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a plating layer between at least one of the pin contact surface and the box
contact surface, and the resin coating.
6. The oil-well metal pipe according to any one of claims 1 to 4, further
comprising:
a chemical conversion treatment layer between at least one of the pin contact
surface and the box contact surface, and the resin coating.
7. The oil-well metal pipe according to claim 5, further comprising:
a chemical conversion treatment layer between the plating layer and the resin
coating.
8. The oil-well metal pipe according to any one of claims 1 to 7, wherein:
the resin coating further containing a rust preventive pigment.