Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
  • F16B17/00—Connecting constructional elements or machine parts by a part of or on one member entering a hole in the other and involving plastic deformation
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L15/00—Screw-threaded joints; Forms of screw-threads for such joints
  • F16L15/001—Screw-threaded joints; Forms of screw-threads for such joints with conical threads
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B19/00—Handling rods, casings, tubes or the like outside the borehole, e.g. in the derrick; Apparatus for feeding the rods or cables
  • E21B19/16—Connecting or disconnecting pipe couplings or joints
  • E21B19/165—Control or monitoring arrangements therefor
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L19/00—Joints in which sealing surfaces are pressed together by means of a member, e.g. a swivel nut, screwed on, or into, one of the joint parts
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/49764—Method of mechanical manufacture with testing or indicating
  • Y10T29/49766—Method of mechanical manufacture with testing or indicating torquing threaded assemblage or determining torque herein

Definitions

• the present invention relates to a method and a device for performing the screwing of a threaded joint for steel tubes provided with a stop and usable in particular in the petroleum industry.
• Such seals have male and female threads which are most generally conical (but which can sometimes be cylindrical), as well as sealing surfaces which come into contact when the joint is screwed, and in most cases, stops. screwing limitation which are intended to suddenly increase the screwing torque so as to immobilize the two elements of the seal in a predetermined position.
• the screwing of joints on building sites is carried out by communicating to one of the elements of the joint with respect to the other a torque of screwing which is located within a predetermined range by the seal manufacturer.
• seals deemed to be identical and screwed with the same tightening torque do not have the same conditions of reliability depending on whether a greater or lesser fraction of the total tightening torque is absorbed by the hooping of the threads and / or by tightening the screwing limitation stops.
• the present invention relates to a new method and a new device which make it possible to apply a predetermined torque to the joint ensure that all the joints thus screwed have identical mounting and sealing characteristics.
• the subject of the present invention is a method for screwing a threaded joint for steel tube intended in particular for the petroleum industry, of the type comprising a male element with external thread and a female element with internal thread, as well that at least one pair of screwing limitation stops located inside the female element, characterized in that before proceeding to screw on the seal, the external surface of the female element is applied, at a certain distance from the plane of the screw-limiting stop and from the side of said plane which is opposite to the threads, a strain gauge which makes it possible to instantly follow the longitudinal deformations of the external surface according to a generator of the female element and that the joint is screwed until the indication provided by the strain gauge corresponds to an extension of a predetermined value of the surface of the female element according to said generator at the level of the gauge.
• strain gauges which measure the deformation on the surface of a metal are simply applied by pressure against said surface, this pressure sufficient to impose on the gauge the deformations undergone by the surface of the metal. .
• the strain gauge is preferably placed at the location of the female element undergoing the maximum longitudinal extension, for example 7 mm from the plane of the screw-limiting stop.
• the present invention also relates to a device for implementing the method described above, device characterized in that it comprises in combination means for applying a strain gauge at a determined location on the external surface of the female element of a joint which is screwed on, and means for example of a known type for measuring the longitudinal deformations of said surface making it possible to interrupt the screwing of the joint when the strain gauge shows a deformation of longitudinal extension of the metal surface of the female element which is at least equal to a predetermined value.
• the device means making it possible to ensure that the longitudinal contraction deformation of the surface of the female element which precedes the extension in the case of conical threads does not exceed a predetermined value , before the screw limiting stops come into contact.
• FIG. 1 is a schematic sectional view of a seal comprising conical threads and screw-limiting stops inside the female element before the latter come into contact,
• Figure 2 is a sectional view corresponding to the. Figure 1 when the joint is fully tightened
• FIG. 3 is a schematic perspective view of a device according to the invention.
• FIG. 4 is a schematic sectional view of the device which applies the strain gauge to the tube
• FIG. 5 is a view showing the theoretical evolution of the longitudinal deformations of the surface of the female element of the joint according to FIGS. 1 and 2
• FIG. 6 represents the theoretical longitudinal deformations of the surface of the female element of a joint comprising cylindrical threads and internal stops for limiting screwing
• FIG. 7 represents the actual curves of the torque and of the deformations of the external surface of the female element actually detected on a joint of the type shown in FIGS. 1 and 2.
• a tubular steel joint for the petroleum industry which comprises a male element 1 and a female element 2.
• This female element 2 can be constituted by a sleeve which comprises its right end is threaded like at its left end or by the thickened end of a tube section.
• the male element 1 has an external frustoconical thread 3, while the female element 2 has an internal frustoconical thread 4 of corresponding shape.
• the male element 1 comprises a stop 5 for limiting the screwing which is applied against the stop 6 for limiting the screwing of the female element 2.
• the male element 1 Due to the fact that the male element 1 has a diameter greater than the internal diameter of the threads 4 of the female element 2 at the threads 3, as the male element 1 is screwed into the female element 2 (and this until the surfaces 5 and 6 come into contact), there is a widening of the diameter of the female element 2 which is represented by the dashed line curve 7 in FIG. 1.
• This trumpet deformation of the female element is reflected by a longitudinal contraction of the outer surface of 'the female element (in the direction of a generatrix) and by a transverse enlargement of the same external surface (in the direction perpendicular to generators).
• FIG. 2 shows the seal of FIG. 1 after the seal has been completely screwed on, that is to say after a tightening torque has been applied to the seal beyond the time when the stops 5 and 6 came into contact with each other.
• the measurement of the longitudinal deformations of the surface of the female element is used using a strain gauge which is applied to the surface of the female element to determine the moment when the tightness of the joint must be stopped.
• the device which makes it possible to detect longitudinal surface deformations of the external surface of the female element is shown diagrammatically in perspective in FIG. 3.
• the female element 2 which is constituted by a sleeve and which includes threads 4 inside which must engage the end of the male element 1.
• the screw-limiting stop 6 as well as the trace 9 of the plane of the screw limiting stop 6 on the external surface of the female element 2.
• the strain gauge is applied to the external surface of the female element 2 by means of the device 10 which is fixed to the female element by a strap 11 schematically represented.
• strain gauge is arranged at a distance D from the plane 6.9 of the stop 6 for limiting screwing on the side opposite that on which the thread 4 of the female element is located.
• strain gauge 12 is applied to the external surface of the female element 2 e being fixed on a part 13 which slides in the block 10 fixed on the tube by the strap 11 and is constantly pushed back by the return spring 14.
• the strain gauge 12 is oriented so as to measure the longitudinal deformations (that is to say in a direction parallel to the axis of the tube).
• FIGs 3 and 4 are only schematic and that the strain gauge 12 can be applied in different ways on the female element.
• this strain gauge 12 can be made integral with the jaw which holds the female element during the screwing of the male element which is then driven in rotation.
• FIGS. 5 to 7 show on the abscissa X the angle of rotation exerted between the male element and the female element and on the ordinate Y the magnitude of the longitudinal deformations of the external surface of the female element during screwing .
• FIG. 5 represents the theoretical evolution of these deformations which are measured by the strain gauge in the direction of the generators.
• the curve 15 of the deformations of the external surface of the female element has a descending part I which corresponds to the period during which the male element sinks into the female element causing the trumpet deformation of the surface external of the latter, which produces a longitudinal contraction of the external surface of the female element, while in part II of the curve 15 which corresponds to the period which followed the contact of the screwing limitation stops, the bump 8a_ of curve 8 in FIG. 2 occurs gradually by causing a longitudinal extension of the external surface of the female element 2.
• FIG. 6 shows the curve of the longitudinal surface deformations of the female element in the case of a joint comprising a cylindrical thread and screwing limiting stops, the deformations being measured at a certain distance from the limiting stop. screwing on the side thereof which is opposite the threads.
• FIG. 7 shows the deformations of the external surface of the female element of a real joint at the same time as the tightening torque.
• the undulations of the compression zone I are explained by the machining tolerances at the threads.
• the contraction reaches a minimum of - 120 when the sealing surfaces and then the screwing limitation stops come into contact (approximately 260 °) to grow at a maximum extension of + 780.
• the minimum value of compression is less than a given value (for example - 200) it is certain that the hooping at the level of the threads has not been excessive.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Mining & Mineral Resources (AREA)
• Geology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Fluid Mechanics (AREA)
• Physics & Mathematics (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Environmental & Geological Engineering (AREA)
• Non-Disconnectible Joints And Screw-Threaded Joints (AREA)
• Earth Drilling (AREA)
• Control Of Motors That Do Not Use Commutators (AREA)
• Pens And Brushes (AREA)
• Mutual Connection Of Rods And Tubes (AREA)
• Details Of Spanners, Wrenches, And Screw Drivers And Accessories (AREA)
• Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)
• Clamps And Clips (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=9308434

Family Applications (1)

Country Status (16)

Families Citing this family (21)

Citations (3)

Family Cites Families (10)

• 1984
  • 1984-10-08 FR FR8415403A patent/FR2571466B1/fr not_active Expired
• 1985
  • 1985-10-08 CN CN85108215.7A patent/CN1003951B/zh not_active Expired
  • 1985-10-08 EP EP85401962A patent/EP0178988B1/fr not_active Expired
  • 1985-10-08 MX MX182A patent/MX163012B/es unknown
  • 1985-10-08 JP JP60504473A patent/JPS62500532A/ja active Granted
  • 1985-10-08 ES ES548345A patent/ES8704610A1/es not_active Expired
  • 1985-10-08 ZA ZA857754A patent/ZA857754B/xx unknown
  • 1985-10-08 BR BR8504992A patent/BR8504992A/pt not_active IP Right Cessation
  • 1985-10-08 CA CA000492503A patent/CA1299349C/fr not_active Expired - Lifetime
  • 1985-10-08 NO NO853990A patent/NO165310C/no unknown
  • 1985-10-08 WO PCT/FR1985/000281 patent/WO1986002123A1/fr not_active Ceased
  • 1985-10-08 US US06/785,397 patent/US4700576A/en not_active Expired - Fee Related
  • 1985-10-08 DE DE198585401962T patent/DE178988T1/de active Pending
  • 1985-10-08 DE DE8585401962T patent/DE3570481D1/de not_active Expired
  • 1985-10-08 SU SU853964115A patent/SU1540661A3/ru active
  • 1985-10-08 KR KR8507427A patent/KR930003295B1/ko not_active Expired - Lifetime
  • 1985-10-08 AU AU48385/85A patent/AU580097B2/en not_active Ceased
• 1987
  • 1987-08-27 US US07/090,230 patent/US4791816A/en not_active Expired - Fee Related

Patent Citations (3)

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