Sumitomo Metal Industries, Inc.

Vallourec & Mannesmann Oil & Gas France

Nippon Steel Sumitomo Metal Corporation

Other

Vallourec Oil and Gas France

Drilltec Patents & Technologies Company, Inc.

Vallourec Industries

Nippon Steel Corporation

Drilltec Patents & Technologies Corporation

Shigeo Nagasaku

Kunio Goto

Masaaki Sugino

Jun Maeda

Miyuki Yamamoto

Shigeo Onishi

Hiroaki Ikegami

Hideo Yamamoto

Masaki Yamano

Keishi Matsumoto

Michihiko Iwamoto

Toshiro Anraku

Yasuhiro Yamamoto

Ikuji Hoshino

Katsutoshi Sumitani

Masaru Takahashi

Gabriel Roussie

Eric Verger

Masanari Kimoto

Thierry Noel

Suguru Yamaguchi

Kazuyuki Nakasuji

Kunihiro Fukui

Ryuichi Imai

David W Clem

Takahiro Takano

Takahiro Hamamoto

Pierre Dutilleul

Akira Narita

Kenichi Ohyabu

Chiaki Akamatsu

The galling resistance of a threaded joint for steel pipes which has a pin with triangular male threads and a box with triangular female threads which threadingly engage with the male threads and an unthreaded sleeve positioned at the end of the box is improved. The unthreaded sleeve is shortened or removed so that the length of the unthreaded sleeve in the axial direction of the box becomes at most &#xbd; (including 0). The shape of the box may be modified by providing a swoosh portion at the end of the box and/or by making the bevel angle at the end of the female threads &#xb1;15 degrees of the flank angle of the female threads.

Threaded joint for steel pipes

A threaded joint for steel pipes having excellent galling resistance, rust preventing properties, and airtightness without using a compound grease comprises a pin and a box each having a threaded portion and an unthreaded metal-to-metal contact portion serving as contact surfaces. The contact surfaces of at least one of the pin and the box are coated with a multi-layered structure comprising, from the bottom, a first layer formed from a first metal or alloy, a second layer formed from a second metal or alloy which is softer than the first metal or alloy, and an uppermost layer of a solid lubricating coating comprising a lubricating powder in an organic or inorganic binder.

An apparatusfor evaluating the performance of a threaded joint for oil country tubular goods using a first steel pipe Pand a second steel pipe Phas a basewhich holds a first steel pipe Pin an upright position with an upper end of the first steel pipe Pextending above the base and the remainder partly disposed under ground. A support membermounted on the baseextends alongside the first steel pipe P. A second steel pipe Pis suspended above the first steel pipe Pby a suspending mechanism. A threaded joint can be connected and disconnected by first and second tongsandwhich rotate the second steel pipe Pwith respect to the first steel pipe P. A stabilizermounted on the support membercan limit the radius of gyration of the second steel pipe P

Test apparatus for a threaded joint for oil country tubular goods

A protector which prevents damage to a solid lubricating coating on a threaded portion of a threaded joint when the protector is mounted on a pin or a box of a threaded joint for pipes in which at least one of the pin or the box is lubricated with a solid lubricating coating comprises a tubular member having a threaded portion on its inner or outer peripheral surface which threadingly engages with at least a portion and preferably 3-5 complete threads of the threaded portion provided on the pin or the box to be protected. The thread height Hof the threaded portion of the protector and the thread height Hof the complete thread of the pin or the box on which the protector is mounted satisfy HH, and the difference between Hand H[=HHis larger than the maximum coating thickness at the thread crest of the solid lubricating coating which covers the threaded portion of the pin or the box.

Protector for tubular threaded joint

A threaded joint for steel tubes has a contact surface () including a threaded portion and a non-threaded metal-to-metal contact portion. The contact surface of at least one of a pin and a box of the joint is coated with a first plating layer () made of a Cu&#x2014;Zn alloy or a Cu&#x2014;Zn-M1 alloy (wherein M1 is at least one element selected from Sn, Bi, and In). An undercoat () of one or both of a Ni plating layer () and a Cu plating layer () and an overcoat of a Sn-M2 alloy plating layer () (wherein M2 is one or more elements selected from Bi, In, Ni, Zn, and Cu) may be formed below and above the first layer, respectively. A solid lubricating coating () and a viscous liquid or semisolid lubricating coating () may also be formed atop the plating layer as a lubricating coating ().

Threaded joint for steel tubes

There is provided a method capable of evaluating a fastening state of a threaded joint that is used as a joint of pipes or tubes such as OCTG with a high degree of accuracy even after being fastened and a method for fastening a threaded joint of pipes or tubes using the evaluating method. The present invention provides a method for evaluating a fastening state of a threaded joint of pipes or tubes including a pin having an external thread part, a metal seal part, and a shoulder part on an outer peripheral surface, and a box having an internal thread part, a metal seal part, and a shoulder part corresponding to each part of the pin on an inner peripheral surface and being fastened with the pin. The evaluating method according to the present invention is characterized by transmitting and receiving an ultrasonic wave to and from a plurality of locations along an axial direction of the threaded joint in at least one of the internal thread part, the metal seal part, and the shoulder part of the box; detecting echo intensities for the plurality of locations; and comparing the echo intensities detected for the plurality of locations to determine whether the fastening state of the threaded joint is good or bad.

Method for evaluating fastening state of threaded joint of pipes or tubes and method for fastening threaded joint of pipes or tubes using the method

An ultrasonic testing method relates to a threaded joint of pipes including a pin having an external thread part, a metal seal part, and a shoulder part on an outer peripheral surface, and a box having an internal thread part, a metal seal part, and a shoulder part with the box and pin being fastened together using a lubricant. The method includes transmitting and receiving ultrasonic waves to and from a plurality of locations along an axial direction of the threaded joint in at least one of the internal thread part, the metal seal part, and the shoulder part of the box; detecting echo intensities and reception times of echoes for the plurality of locations; and detecting an abnormal portion in the threaded joint based on a longitudinal axial directional distribution of the echo intensities and longitudinal axial directional distribution of reception times of the echoes.

Ultrasonic testing method of threaded joint of pipes or tubes

A threaded joint for steel pipes comprising a pinhaving a tapered male thread, a tapered sealing surface, and an end shoulder surfaceand a boxhaving correspondingly a tapered female thread, a tapered sealing surface, and a shoulder surfacewhich is capable of easy tightening and has improved air tightness by the sealing surfaces is arranged such that the pin and the box each have a noncontacting region B where the peripheral surfaces of the pin and the box do not contact each other between the sealing surfacesand the shoulder surfacesand. At least a portion of the noncontacting region of the pin adjoining the to end of the pin is a tapered surface portionhaving substantially the same angle of slope as the tapered sealing surface, and the noncontacting region of the box is a substantially cylindrical surface.

A threaded joint for steel pipes comprises a pin () and a box (). The pin has male thread (), a sealing surface (), and a shoulder surface () located on the end face of the pin. Correspondingly, the box has female thread (), a sealing surface (), and a shoulder surface () which can mate or contact with the corresponding portions of the pin. The shoulder surface () of the pin () is provided at an end face of the pin. The sealing surface () of the pin () is located on a pipe end side near the male thread (). A a nose portion () is provided on the pin () between the sealing surface () and the shoulder surface (), the nose portion () being not in contact with a corresponding portion of the box ().

A threaded joint for steel pipes comprised of a pin () and a box () each having a threaded portion () and an unthreaded contact portion () exhibits adequate leakage resistance and galling resistance when used for makeup of oil country tubular goods with application of a green dope or even without any dope. The threaded joint has a first plating layer of Sn&#x2014;Bi&#x2014;Cu alloy plating formed on the contact surface of at least one of the pin () or the box (). The first plating layer may have a second plating layer selected from Sn plating, Cu plating, and Ni plating on its lower side and at least one layer of a lubricating coating, and particularly a solid lubricating coating on its upper side.

In a threaded joint for steel pipes which are connected by threaded engagement of a pin member having a tapered male thread, a metal seal-forming portion, and a torque shoulder-forming portion on the end of a pipe, and a box member having a tapered female thread, a metal seal-forming portion, and a torque shoulder forming-portion corresponding to these on the end of a pipe, a buttress thread having contact at the load flanks and the thread root surface and gaps at the thread crest surface and the stabbing flanks is mixed in a single joint with a rugged thread having contact at the load flanks and stabbing flanks and having gaps at the thread root surface and thread crest surface.

A threaded joint for steel pipes comprising a pinand a boxeach having a contact surface comprising a threaded portionorand an unthreaded metal contact portionis provided with improved anti-galling propertied by forming a lubricating coating on the contact surface of at least one of the pin and the box, the lubricating coating exhibiting a self-repairing function by liquid lubrication and having a decreased greasiness. The lubricating coating is (1) a coating which comprises a lower lubricant layer which is in liquid form in the temperature range of above 0&#xb0; C. and below 40&#xb0; C. and an upper lubricant layer which is in solid form at 40&#xb0; C., or (2) a coating which is semi-solid or solid at 40&#xb0; C. and is formed of a mixture comprising a lubricating oil which is in liquid form in the temperature range of above 0&#xb0; C. and below 40&#xb0; C. and a wax which is in solid form at 40&#xb0; C., the mixture preferably having been heated so as to liquefy the wax and dissolve in each other the wax and lubricant oil.

A lubricating coating composition in which at least one basic lubricant selected from a basic sulfonate, a basic salicylate, and a basic phenate is dissolved in a volatile solvent is applied to the frictional surface of a box and a pin constituting a threaded joint for oil well pipes. The composition may further contain one or more of a thermoplastic resin powder, another lubricant, and an extreme pressure agent. The surface roughness of the frictional surfaces preferably has an Rmax in the range of 5-40 micrometers.

Lubricating coating composition suitable for lubrication of a threaded joint

A threaded joint for oil well pipes is provided which can guarantee a joint efficiency sufficient for practical use in deep wells, which has a decreased joint outer diameter, and which has an improved bending resistance, compression resistance, and over-torque resistance which are sufficient for use by the side track technique. It is an integral threaded joint for oil well pipes in which it has a joint efficiency of at least 70%, the outer diameter of the joint is larger than and at most 1.08 times the outer diameter of the oil well pipe bodies, and the threaded portions have a cross section of a trapezoidal shape with a load flank angle (&agr;) of the threads in the range of 0 to &minus;20 degrees and a stabbing flank angle (&thgr;) thereof in the range of 35 to 50 degrees.

Growing community of inventors

Nishinomiya, Japan

Shigeo Nagasaku