Key information

Title
A coupling assembly
Application number
20221334
Case type
National
Status
07.09.2026 Patent meddelt (B1)
Filed
13.12.2022
Effective date
13.12.2022
Publicly available
14.06.2024
Next annual fee due
31.12.2026
Applicant
Torsion Tool Company AS (NO)
Owner
Torsion Tool Company AS (NO)
Inventor
Olav Olsen (NO)
Agent
ZACCO NORWAY AS (NO)
Granted
07.09.2026
Patent number
350119
Expiry date
13.12.2042

Abstract and drawing

Disclaimer: This text has been machine-scanned and may contain errors – please refer to "Publications" for legally binding content.
A coupling assembly for elongated elements (1, 2) comprises a pin member (5) having an outward-facing pin surface (12) and a box member (6) having an inward-facing box surface (13). The assembly comprises one or more elongated flexible locking member (30). The pin member (5) is provided with one or more first circular and circumferential groove (31), and the box member (6) is provided with one or more corresponding second circular and circumferential groove (32). When the pin-andbox connection is made up, a set of first groove (31) and second groove (32) are aligned and the grooves form a circular and circumferential channel (41) shaped and dimensioned for receiving the elongated flexible locking member (30).

Publications

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Documents

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Date
 Date Doc. No. Process Case number In/Out Journal description To/from
 07.09.2026 11-01 Saksbehandling 20221334(350119) UT PT Registreringsbrev nasjonal patent (15) (PT20221334)
20.07.2026 10-01 Saksbehandling 20221334 UT PT Meddelelse om patent ZACCO NORWAY AS
 16.06.2026 09-04 Saksbehandling 20221334 INN P342024NO00 Specification and claims for grant - tracked ZACCO NORWAY AS
 16.06.2026 09-03 Saksbehandling 20221334 INN P342024NO00 Specification and claims for grant - clean ZACCO NORWAY AS
 16.06.2026 09-02 Saksbehandling 20221334 INN P342024NO00 Response to 2nd Office Action ZACCO NORWAY AS
 16.06.2026 09-01 Saksbehandling 20221334 INN Korrespondanse (Hovedbrev inn) ZACCO NORWAY AS
 06.03.2026 08-03 Saksbehandling 20221334 UT Amended claims EP4634557A1
06.03.2026 08-02 Saksbehandling 20221334 UT PT report 10:49:21
06.03.2026 08-01 Saksbehandling 20221334 UT Realitet patent ZACCO NORWAY AS
 06.03.2026 07-01 Saksbehandling 20221334 INN Amended claims EP4634557A1
04.11.2024 06-01 Saksbehandling 20221334 UT PT Varsel om betaling av første årsavgift (3317) (PT20221334) ZACCO NORWAY AS
 27.11.2023 04-01 Saksbehandling 20221334 INN Korrespondanse (Hovedbrev inn) ZACCO NORWAY AS
 17.08.2023 05-04 Saksbehandling 20221334 INN P342024NO00 Response to OA1 563869 ZACCO NORWAY AS
 17.08.2023 05-03 Saksbehandling 20221334 INN P342024NO00 Amended claims in response to OA1 track changes- MU 563866 ZACCO NORWAY AS
 17.08.2023 05-02 Saksbehandling 20221334 INN P342024NO00 Amended claims in response to OA1 - CLEAN 563865 ZACCO NORWAY AS
 17.08.2023 05-01 Saksbehandling 20221334 INN Korrespondanse (Hovedbrev inn) ZACCO NORWAY AS
 12.04.2023 03-02 Saksbehandling 20221334 UT PT report 11:07:03
12.04.2023 03-01 Saksbehandling 20221334 UT 20221334_1696857_PT 08 ZACCO NORWAY AS
 14.12.2022 02-01 Saksbehandling 20221334 UT Informasjon til oppfinner Olav Olsen
 13.12.2022 01-05 Saksbehandling 20221334 INN Specification and claims ZACCO NORWAY AS
 13.12.2022 01-04 Saksbehandling 20221334 INN Generalfullmakt Norge ZACCO NORWAY AS
 13.12.2022 01-03 Saksbehandling 20221334 INN Figures ZACCO NORWAY AS
 13.12.2022 01-02 Saksbehandling 20221334 INN Erklæring om retten til oppfinnelsen ZACCO NORWAY AS
 13.12.2022 01-01 Saksbehandling 20221334 INN Søknadsskjema Patent ZACCO NORWAY AS

Description, claims and drawings

Disclaimer: This text has been machine-scanned and may contain errors – please refer to "Publications" for legally binding content. Description
3501191A coupling assemblyField of the inventionThe invention relates to the field of couplings for connecting elongated elements, such as pipes, tubes, rods, shafts or axles. More specifically, the invention concerns a 5 coupling assembly as specified in the preamble of claim 1.Background of the inventionPipe sections or tubular sections used for drilling deep wells in e.g. oil or gas reservoirs or geothermal formations, utilize long sections of drill pipe, well casing or tubing that traditionally have a tapered, exteriorly-threaded male end called a pin member. In use, 10 the pin members are threaded into corresponding couplings, collars or integral female pipe sections; their threaded ends are called a box member. These box members have an interiorly-threaded tapered thread corresponding to their respective pin members.A dominant type of pin-box connection has been the American Petroleum Institute (API) threaded and coupled connection that achieves its assembly with threads and 15 torque shoulders. These tapered connections provide increasing bearing stresses to the seal between the pin member and box member with increasing engagement produced by rotational torque. Hydraulic tongs, often referred to as an “iron roughneck”, or manually operated tongs are normally used to make up connections between drill pipe, while socalled “casing tongs” are used to make up casing and production pipe (or liner). 20 As the well depths and lengths (as well as the number of long horizontal wells and directional wells) have increased, the drilling and production environment has become more demanding. For example, a well of 6000 meters may require as much as 7000 connections and disconnections of pipe, with varying torque. The threaded pin-box connections need to meet rigorous demands regarding pressure loss across the 25 connection, tension / compression resistance, higher torque, and resistance to internal and external pressure. The threaded connections developed to meet these demands are referred to as "premium" connections and “double-shoulder connection” (DSC).The prior art includes US 3923 324 A, which describes a drill collar for a rotary drill string, including a threadless drill collar body having pins being frictionally mounted by 3501192means of a shrink-fit on opposite ends of the body, to corresponding boxes of opposite subs. The frictional connection between the matching conical surfaces between conical pins of the drill collar body, and the corresponding subs, respectively, is accomplished as by the application of pressure fluid between the adjacent contacting surfaces, while 5 simultaneously applying an axial force, as by fluid or hydraulic pressure, to push or force the box shaped portion of each sub onto its companion conical pin of the drill collar body, until such box shaped member abuts a shoulder adjacent the connection of the conical pins with the main drill collar body. A port is provided in the box shaped portions of each sub for introduction of gaseous or hydraulic fluid pressure into the 10 space between the box and pin, for laterally expanding the sub box during shrink-fitting thereof onto the corresponding pin.The prior art also includes GB 2113 335 A, GB 2180 312 A, GB 2113 334 A, and US 4 561 683 A.An example of the prior art is illustrated in figures 1 and 2. A coupling assembly 15 comprises a first mating member 5 and a second mating member 6, the first mating member being a pin member 5 which forms an end portion of a first pipe 1 having an internal bore 3. The second mating member is a box member 6 which forms an end portion of a second pipe 2 having an internal bore 4. Only a part of the first and second pipes 1,2 are shown. The pipes 1,2 may for example be drill pipes, liners, casing joints 20 or other tubular elements configured for rotational movement and for conveying a fluid.In fact, although not illustrated, the pipes may be replaced by other elongated elements such as shafts and axles.The pin member 5 comprises a first mating surface 12, hereinafter also referred to as a pin surface 12, here in the shape of a frusto-conical surface facing outwards with respect 25 to a central axis. The pin surface ends at a pin shoulder 14. The box member 6 comprises a second mating surface 13, hereinafter also referred to as a box surface 13, here in the shape of a frusto-conical surface facing inwards with respect to the central axis. The box surface ends at an internal box shoulder 16. Such pin-and-box shapes are well known in the art. Seals (not shown) may be arranged at the pin shoulder 14 and the 30 pin free end 15, or (more common) at the pin free end 15 and the box inner shoulder 16.The seals may be integrated (as profiles in the pin and/or box) or may be removable, 3501193and may comprise materials such as elastomers and/or metals. It should be understood, however, that the pin-and-box coupling may also be used without seals.In the embodiment illustrated in figures 1 and 2, the pin surface 12 and box surface 13 are plain surfaces, without helical threads or other pronounced protrusions configured 5 for mating engagement. The pin and box surfaces are thus generally smooth, but may comprise a textured finish (roughness) of a certain topography in order to augment static friction (and hence adherence) between the pin and box when connected. Such topography may be obtained by friction coating (by for example nickel coating with diamonds) or by increasing surface roughness through sandblasting or similar. Although 10 not illustrated, the pin and/or box surfaces, or portions of these surfaces, may be furnished with serrations in order to increase the torque capacity of the connected coupling.Arranged in the external wall of the box member 6 is an opening (a port) 9a which is the outward opening of a bore 9 extending through the box member wall and into the box 15 member interior, penetrating the box surface 13 in an inward opening 9b. The bore 9 therefore provides a fluid access channel into the box. It should be understood that although only one bore 9 is shown in the figures, a practical embodiment may comprise several bores.Seals 7, 8 are arranged in the region of the pin shoulder and pin free end, respectively. 20 However, the seals may be arranged on the box instead, and a combination of the two arrangements is conceivable. The seals serve to form a frusto-conical annular cavity during the initial mating, to contain injected fluid. Figure 1 also shows how a pressurized fluid reservoir 10 is connected to the bore 9 via a conduit 10a. The reservoir 10 preferably contains a liquid, such as (but not necessarily limited to) water, which 25 may be injected under pressure into the box member 6, controlled via the control valve 11. Figure 1 also illustrates an alternative configuration in which the reservoir 10 is connected to a bore 9’ which extends through the pin member 5 body, and where the bore 9’ penetrates the pin surface 12 with the opening 9b. The effect of this configuration is equivalent to the configuration in which the bore 9 extends through the 30 box member 5 wall inasmuch as both bore configuration deposit the injected fluid at more or less the same location during a mating operation. However, connecting the 3501194reservoir 10 to the bore 9’ extending through the pin member 5 body may have certain operational advantages.In figure 2, the pin member 5 and box member 6 have been moved together in an axial movement (i.e. no rotation necessary), a pressurized hydraulic liquid (e.g. water) is 5 injected from the reservoir 10 through the bore 9 (or bore 9’) when the seal 7 and the seal 8 have created a cavity V between the pin surface 12 and the box surface 13. This cavity V, which essentially is an annular, frusto-conical, cavity, is very small compared to the dimensions of the pin and box surfaces and therefore only appears as a solid black line in figure 7. The fluid pressure inside the cavity V causes elastic deformation in the 10 pin member and box member, such that the box member wall expands radially (see arrows “E” in figure 2) and the pin member is compressed radially (see arrows “C” in figure 2). This deformation allows the pin member to be inserted an additional distance d into the box member. At the stage where the box free end meets the shoulder on the pin member, the fluid pressure is released, causing the pin and box members to resume 15 their original shape and thus forming a tight and high-tension connection.The prior art also includes WO 2018/143819 A1, by the present inventor and incorporated here as a reference in its entirety, disclosing a coupling assembly for elongated elements comprising a pin member and a box member. The pin and box members have complementary and respective frusto- conical pin and box mating 20 surfaces. A bore has as a first opening a port configured for connection to an injection fluid reservoir and a second opening penetrating the pin mating surface or the box mating surface. The surfaces may be plain surfaces without helical threads or other pronounced protrusions configured for mating engagement, but comprise a textured finish in order to augment static friction between the surfaces when the surfaces are 25 connected. The pin surface may comprise a plurality of protruding portions separated by recessed portions, and the box surface may also comprise a plurality of protruding portions separated by recessed portions. Each pin protruding portion is shaped and dimensioned to fit into a designated box recessed portion, and each box protruding portion is shaped and dimensioned to fit into a designated pin recessed portion. 30 The prior art also includes US 6981 547 B2, which discloses an expandable connection for a wellbore tubular, comprising a first tubular member having a variable pitched 3501195groove formed on an inside surface thereof and a second tubular member having a variable pitched groove formed on an outside surface thereof, wherein the tubular members are mateable to form a variable pitched continuous recess through the variable pitched grooves; and an aperture formed in a wall of the first tubular, the aperture 5 provides a pathway for inserting a wire into the variable pitched continuous recess, whereby the wire rotationally and axially fixes the first tubular member to the second tubular member.The prior art also includes US2458714A, which describes a coupling comprising two tubular conduits having adjacent ends positioned one inside the other and arranged for 10 pivotal adjustment.The inner conduit has an annular shoulder for engagement by the end of the outer conduit and an annular bushing is interposed between the joined ends of the conduits. The bushing has an end abutting an annular shoulder on the inner conduit and its opposite end formed with an annular beveled edge.The prior art couplings are predominantly concerned with handling either torque or 15 compression/tension. There is a need for an improved coupling, that is more reliable and efficient, and which offers more operational advantages over the prior art.Summary of the inventionThe invention is set forth and characterized in the main claim, while the dependent claims describe other characteristics of the invention. 20 It is therefore provided a coupling assembly for elongated elements, comprising a pin member having an outward-facing pin surface, and a box member having an inwardfacing box surface; said pin surface and box surface configured for mating engagement, and seals on the pin member and/or the box member define a volume between the pin member and the box member when mated; 25 characterized by- one or more elongated flexible locking members and- the pin member is provided with one or more first circular and circumferential, nonhelical, groove and- the box member is provided with a corresponding at least one circular and 30 circumferential, non-heliucal, groove and, 3501196- the box member (6) is provided with at least one insertion port (35) aligned with the at least one second groove,- whereby, when the pin-and-box connection is made up, a first groove and a corresponding second groove are aligned and form a circular and circumferential 5 channel shaped and dimensioned for receiving an elongated flexible locking member;wherein an at least one bore has a first opening configured for connection to an injection fluid reservoir and a second opening penetrating the pin surface or the box surface, whereby a fluid may be injected into said volume formed between at least a portion of an outer pin surface and a corresponding inner box surface portion. 10 In one embodiment, the circular grooves are arranged perpendicularly to a longitudinal axis of the box and pin. In one embodiment, the elongated flexible locking member material has a higher strength than that of the box and pin material. In one embodiment, the elongated flexible locking member is a wire or flexible rod.In one embodiment, the coupling assembly comprises an insertion port on the box 15 member, the insertion port aligned with the channel formed by the first and second grooves.The locking member may comprise a fastener element, and the box member may comprise a slot in the vicinity of the insertion port, the slot configured for receiving the a fastener element. The locking member length may correspond to the channel 20 circumference.In one embodiment, the pin surface comprises a plurality of pin protruding portions separated by pin recessed portions, and the box surface comprises a plurality of box protruding portions separated by box recessed portions; and wherein a pin protruding portion is shaped and dimensioned to fit into a designated box recessed portion, and 25 wherein a box protruding portion is shaped and dimensioned to fit into a designated pin recessed portion.In one embodiment, the elongated flexible locking member comprises an axial bore, whereby a fluid may be injected into the volume or volumes formed between the pin and box surfaces. 3501197The invented coupling assembly may be connected and disconnected without rotational motion (as is necessary with a threaded connection), only axial motion and application of hydraulic pressure are required. The pin and box surfaces may be smooth or comprise complementary stepped profiles (protruding and recessed portions). Adhesion between 5 the surfaces may be augmented by friction coating (e.g. electrode-less nickel coating with diamonds or similar), a serrated surface, particles in the injected fluid, “doublehelix engravement” (fluid pressure distribution and friction particles distribution), separate friction sleeves, or/and by increasing surface roughness (by e.g. sandblasting or similar). 10 Besides the bias created by hydraulics and steel elastic properties, the friction factor between the pin and box will contribute to the connection. The hydraulic fluid may be water or glue with or without a corrosion inhibitor, with or without particles , together with a surface structure or/and a separate friction shim, or/and an applied friction increasing coating, seeking the highest possible friction factor. The elongated flexible 15 locking member prevents “creepage”, or “microslip”, i.e. a tendency for the pin to be forced out of the box when the rotating pin-and-box connection is subjected to tension and alternating bending moments. The invented coupling exhibits improved performance over the prior art, in that it can handle combined torque, tension and compression, and internal and external fluid pressures. 20 The invented coupling assembly may be useful for connecting any elongated elements that may rotate and transfer torque; such as pipes, propeller shafts, axles, as well as various tubulars such as drill pipe (drill string) and casing for casing-drilling. The invented coupling assembly transfers torque equally well in both rotational directions (as opposed a prior art threaded coupling). This “bidirectional” torque capability is 25 particularly useful is a drill pipe is jammed and it is necessary to counter-rotate to release the drill bit or other downhole tools. The coupling assembly may also be useful for non-rotating elongated elements, such as rods, different process pipe lines, borehole casings and liners.The invention is suitable with any materials commonly used in pipes, propulsion shafts, 30 axles, drill pipe (drill string), drilling risers, rods, borehole casings, liners, etc., such as stainless steel. However, the invented coupling also lends itself to the use of various 3501198steel grades (e.g.100ksi box and 130ksi pin), light-weight materials, such as fibrereinforced composites, titanium, aluminum and similar alloys. That is, both the coupling and the associated elongated elements may be made of such materials (or in combination). This will allow for a significant weight reduction of e.g. drill strings, 5 compared to the steel drill strings of the prior art. The invention also comprises a combination in which the pin and box are of different materials.Brief description of the drawingsThese and other characteristics of the invention will become clear from the following description of embodiments, given as non-restrictive examples, with reference to the 10 attached schematic drawings, wherein:Figure 1 is a schematic sectional view of a coupling assembly according to the prior art, in a plane along a longitudinal central axis, in a disconnected state;Figure 2 corresponds to figure 1, and illustrates a method of connecting the pin member and the box member; 15 Figure 3a is a perspective view of an embodiment of the invention, illustrating a pin and box and a locking member in a disconnected state, and figures 3b and 3c are enlarged views of areas C and D, respectively, in figure 3a;Figure 4 is a sectional schematic view of the coupling assembly shown in figure 3a, in a plane along the longitudinal central axis x-x, in a disconnected state; 20 Figure 5a is a transparent side view of the embodiment illustrated in figure 3a, in a mated and locked state, and figure 5b is an enlarged view of area E in figure 5a;Figure 6a is a close-up and transparent side view of the embodiment illustrated in figure 5a, in a mated and locked state;Figures 6b and 6c are enlarged views of area F in figure 6a, where the locking 25 member is removed and the pin and box have been separated for clarity of illustration;Figures 7 to 10 are perspective views of the embodiment illustrated in figures 3a-c, and illustrate different steps in a mating (or, if seen in the reverse order: a disconnection) procedure; 3501199Figure 11 is a close-up and transparent perspective view of the embodiment illustrated in figure 10, in a mated and locked state;Figure 12 is a perspective view of a further embodiment of the invention, illustrating i.a. a pressure fitting (in an exploded view); 5 Figures 13 and 14 are perspective views of the embodiment illustrated in figure 12, and illustrate i.a. the insertion (or, if seen in the reverse order: removal) of the locking member through the pressure fitting;Figures 15-19 illustrate another embodiment of the invention, comprising a plurality of channels and corresponding elongated locking members; 10 Figures 20-22 illustrate another embodiment of the invention, comprising two volumes, one on each side of the plurality of channels; andFigure 23 is an enlarged view of area G in figure 20, and illustrates an embodiment of the elongated locking member having an internal fluid channel.Detailed description of embodiments 15 The following description will use terms such as “horizontal”, “vertical”, “lateral”, “back and forth”, “up and down”, ”upper”, “lower”, “inner”, “outer”, “forward”, “rear”, etc. These terms generally refer to the views and orientations as shown in the drawings and that are associated with a normal use of the invention. The terms are used for the reader’s convenience only and shall not be limiting. 20 Referring initially to figures 3a to 3c, the invented coupling assembly comprises a first mating member 5 and a second mating member 6. In the illustrated embodiment, the first mating member is a pin member 5 which forms an end portion of a first pipe 1 having an internal bore 3. The second mating member is a box member 6 which forms an end portion of a second pipe 2 having an internal bore 4. It should be understood that 25 only a part of the first and second pipes 1,2 are shown, and the skilled person will understand that these pipes may be several meters long. The pipes 1,2 may for example be drill pipes, liners, casing joints or other tubular elements configured for rotational movement and for conveying a fluid. In fact, although not illustrated, the pipes may be replaced by other elongated elements such as shafts and axles. The invention shall 35011910therefore not be limited to a coupling assembly for tubular elements, but be applicable to a coupling assembly for any elongated elements interconnected by a pin-and-box connection. Therefore, this description will hereinafter refer to first and second elongated elements 1,2. 5 The pin member 5 comprises a first mating surface 12, hereinafter also referred to as a pin surface 12, here in the shape of a frusto-conical surface facing outwards with respect to the central axis x-x. The pin surface ends at a pin shoulder 14.The box member 6 comprises a second mating surface 13, hereinafter also referred to as a box surface 13, here in the shape of a frusto-conical surface facing inwards with 10 respect to the central axis x-x. The box surface ends at an internal box shoulder 16.Such pin-and-box shapes are per se well known in the art, and need therefore not be described in further detail here. Seals (not shown) may be arranged at the pin shoulder 14 and the pin free end 15, or (more common) at the pin free end 15 and the box internal shoulder 16. The seals may be integrated (as profiles in the pin and/or box) or may be 15 removable, and may comprise materials such as elastomers and/or metals. It should be understood, however, that the pin-and-box coupling may also be used without seals. In the embodiment illustrated in figures 1-5b, the pin surface 12 and box surface 13 are plain surfaces, without helical threads or other pronounced protrusions configured for mating engagement. 20 The pin and box surfaces are thus generally smooth, but may comprise a textured finish (roughness) of a certain topography in order to augment static friction (and hence adherence) between the pin and box when connected. Such topography may be obtained by friction coating (by for example nickel coating with diamonds) or by increasing surface roughness through sandblasting or similar. Although not illustrated, the pin 25 and/or box surfaces, or portions of these surfaces, may be furnished with serrations in order to increase the torque capacity of the connected coupling.Although not illustrated, another adherence-enhancing topography may be that the frusto-conical pin surface is provided with grooves, extending in a double-helical formation. This is described in more detail in the above-mentioned WO 2018/143819 30 A1, by the present inventor. The grooves are preferably quite shallow in relation to the 35011911dimensions of the pin and box, for example a groove depth be on the order of one tenth of a millimeter for a pin having an outer diameter (OD) of 120mm. A double helix may also be formed in the box surface, either in lieu of the double-helical formation in the pin or as a supplement to it. The helical grooves serve two functions, by providing a) 5 fluid distribution channels during mating and b) distribute friction-enhancing fluid with particles.Although not illustrated, the pin surface 12 and box surface 13 may each comprise radially protruded portions and radially recessed portions. More specifically, the pin surface 12 may comprise successive (in the axial direction) circular and radially 10 protruding portions (“pin rings”) and circular and radially recessed portions (“pin recesses”). Correspondingly, the box surface may comprise successive (in the axial direction) circular and radially protruding portions (“box rings”) and circular and radially recessed portions (“box recesses”). The axial widths of the pin rings and pin recesses decrease in the direction towards the pin free end; that is, the widths are greater 15 in the region of the pin shoulder than in the region of the pin free end. Conversely, the axial widths of the box rings and box recesses increase in the direction towards the box free end; that is, the widths are smaller in the region of the box inner shoulder than in the region of the box free end (opening). This is described in more detail in WO 2018/143819 A1, by the present inventor, in which the key-and-lock functionality is 20 referred to as the “Key-Loc” concept. A central feature of this concept is that all ringand-recess pairs must be aligned before the initial mating is complete.Referring now to figures 5a,b and 6a-c, the pin member 5 is provided with a first circular and circumferential groove 31, and the box member 6 is provided with a second circular and circumferential groove 32. In the illustrated embodiment, the circular 25 grooves are arranged perpendicularly (not helically) to the longitudinal axis of the box and pin, i.e. with no pitch. Reference numbers 33 and 7’ denote seal grooves on the box 6 and pin 5, respectively (a seal is not illustrated). Reference number 38 points to a chamfer at the box 6 free end. This chamfer is useful during the assembly procedure, as the box free end (tip) does not deform (elastically) as much as the main portion of the 30 box during the liquid injection. 35011912When the pin-and-box connection is made up, by applying the fluid pressure as described above, the first groove 31 and the second groove 32 are aligned and form a circular and circumferential channel 41. This channel is shaped and dimensioned for receiving an elongated flexible locking member 30, preferably in the form of a locking 5 wire or flexible rod 30 (see e.g. figures 5b, 6a and 7). In one embodiment, the locking member material has a higher strength than that of the box and pin material.The assembly (mating, stabbing) procedure is performed generally by the same procedure as for the embodiments described above. In figure 7, the pin 5 has been inserted into the box 6 until mechanical friction (due to interference) prevents further 10 mating. In figure 8, fluid (e.g. water) has been injected into the connection via fluid port 9a, as described above, whereby the box 6 is expanded radially and the pin 5 is compressed radially, and the pin and box are moved into a fully mated state (i.e. tip abuts shoulder, as described above). At this stage of the assembly procedure, the locking member 30 is inserted into an insertion port 35 on the box 6 until a fastener 15 element 34 is lodged in a complementary-shaped slot 36 in the vicinity of the insertion port 35, see figures 9 and 10. The insertion port 35 is aligned with the channel 41 formed by the first and second grooves 31, 32. A further close-up view is provided by figure 11. If the pin-and-box connection, when made up and in use, will be subjected to rotation, the grooves and insertion port are oriented towards (opposite to) the direction 20 of rotation, in order to prevent the locking member from being dislodged during rotation.At this stage of the assembly process, the liquid is allowed to bleed off through the fluid port 9a, as described above, whereupon the box 6 is allowed to contract radially and the pin 5 is allowed to expand radially, and the locking member 30 is compressed between 25 the pin and box. With the locking member 30 in place, the pin-and-box connection tensile strength is improved, while the torsion strength is maintained.Breaking the pin-and-box connection is performed using a reversed procedure.It will be understood that the locking member 30 length preferably corresponds to the channel circumference, whereby the locking member fills substantially the entire length 30 of the channel. As an alternative embodiment, the locking member thickness (e.g. 35011913diameter) may be dimensioned such that the locking member may be inserted (and removed) even when the pin-and-box connection is fully made up, i.e. after the liquid has been bled off.Although only one locking member 30 and channel (i.e. aligned grooves 31, 32) have 5 been illustrated in the figures referred to above, it should be understood that several such locking member and channels may be arranged along the axial length of the pin and box. This is illustrated in figures 15-19, wherein the pin and box are provided with four respective grooves 311-4, 321-4, the box is provided with four injection ports 35 and four elongated locking members 30 are configured for insertion into respective channels 10 411-4 formed by a pair of aligned grooves 31, 32. It should be understood that the pin and box may comprise fewer or more grooves.Figure 18 illustrates a variant in which the box is provided with two sets of four injection ports 35’, 35’’, arranged on diametrically opposite sides of the box, whereby respective elongated locking members 30 may be inserted in each injection port. In this 15 variant of the invention, the length of the locking members 30 are half of the length of the locking member described above, i.e. about half the length of the channel formed by the aligned grooves. (Although not illustrated in figures 15-20, it should be understood that also this embodiment comprises fluid ports as described above.)A further variant is illustrated in figures 12-14. Here, a pressure fitting 40 is arranged in 20 the insertion port 35. The pressure fitting maintains the pressure inside the volume formed between the pin-and-box connection and allows the locking member 30 to be inserted into the above mentioned channel when the volume V (see figure 2) is pressurized by inserted fluid. Although not illustrated, the locking member 30 may be forced into the channel via a fluid pressure in a pipe or tube, or by a mechanical device. 25 Figures 20-22 illustrates an embodiment having two volumes V1, V2, arranged on each side of the channels 411-4. Each volume is accessible via respective fluid channels and ports 9’a, 9’’a. Figure 20 illustrates a variant having four insertion ports 35, but this embodiment may have fewer or more insertion ports (and channels 41). Figure 21 illustrates an initial stage of a mating process, in which a first volume V1 is defined by a 35011914first set of seals 42a,b, and a second first volume V2 is defined by a second set of seals 43a,b. Figure 22 illustrates a mated state.Figure 23 illustrates an embodiment of the elongated locking member 30’ having an axial bore 44. The axial bore may be used as a supply channel for fluid into the volumes 5 formed between the pin and box, thus removing the need for a separate fluid port 9a;9’a; 9”a.It should be understood that embodiments described above may be combined, even though not every combination is illustrated in the figures.Break-out is accomplished by applying a suitable liquid pressure through one (or more) 10 of the conduits similarly to the procedure explained above, whereupon the pin may be released (and withdrawn) from the box.The invented coupling assembly is preferably without conventional threads and therefore requires no rotation during connection or disconnection. The time required to connect and disconnect the coupling is therefore reduced significantly. By injecting the 15 hydraulic fluid between the frusto-conical pin surface and box surface, elastic expansion of the box member and elastic compression of the pin member is accomplished, which enables a completion of the connection.The invented coupling assembly will also allow the pipe joint cross-section to be reduced, as there is no need for traditional iron-roughneck, manual rig tongs or bucking 20 units. On-site handling challenges are therefore mitigated.The hydraulic friction coupling as described above will also allow drilling of significantly longer and deviated wellbores, as friction loss by circulating drilling fluid is reduced, and the torque capacity of the pipe joint is increased. The invented coupling assembly will also lower the sequence time (make or break) significantly and hence the 25 cost of drilling.
Claims
35011915Claims1. A coupling assembly for elongated elements (1, 2), comprising a pin member (5) having an outward-facing pin surface (12), and a box member (6) having an inwardfacing box surface (13); said pin surface and box surface configured for mating5 engagement, and seals (7, 8) on the pin member (5) and/or the box member (6) define a volume (V) between the pin member (5) and the box member (6) when mated;characterized by- one or more elongated flexible locking members (30; 30’), and- the pin member (5) is provided with one or more first circular and circumferential,10 non-helical, groove (31), and- the box member (6) is provided with a corresponding at least one circular and circumferential, non-helical, groove (32) and,- the box member (6) is provided with at least one insertion port (35) aligned with the at least one second groove (32),15 - whereby, when the pin-and-box connection is made up, a first groove (31) and a corresponding second groove (32) are aligned and form a circular, non-helical, and circumferential channel (41) shaped and dimensioned for receiving the elongated flexible locking member (30; 30’);wherein an at least one bore (9) has a first opening (9a) configured for connection to an20 injection fluid reservoir (10) and a second opening (9b) penetrating the pin surface (12) or the box surface (13), whereby a fluid may be injected into said volume (V) formed between at least a portion of an outer pin surface (12) and a corresponding inner box surface (13) portion.2. The coupling assembly of claim 1, wherein the circular grooves are arranged25 perpendicularly to a longitudinal axis of the box and pin.3. The coupling assembly of claim 1 or claim 2, wherein the elongated flexible locking member (30) material has a higher strength than that of the box and pin material.4. The coupling assembly of any one of claims 1-3, wherein the elongated flexible30 locking member (30) is a wire or flexible rod.350119165. The coupling assembly of any one of claims 1-4, further comprising an insertion port (35) on the box member (6), the insertion port (35) aligned with the channel formed by the first and second grooves (31, 32).6. The coupling assembly of any one of claims 1-5, wherein the locking member5 (30) further comprises a fastener element (34).7. The coupling assembly of any one of claims 1-6, wherein the box member (6) comprises a slot (36) in the vicinity of the insertion port (35), the slot configured for receiving a fastener element (34).8. The coupling assembly of any one of claims 1-7, wherein the locking member10 length correspond to the channel circumference.9. The coupling assembly of any one of claims 1-8, wherein the pin surface (12) comprises a plurality of pin protruding portions separated by pin recessed portions, and the box surface (13) comprises a plurality of box protruding portions separated by box recessed portions; and wherein a pin protruding portion is shaped and dimensioned to fit15 into a designated box recessed portion, and wherein a box protruding portion is shaped and dimensioned to fit into a designated pin recessed portion.10. The coupling assembly of any one of claims 1-9; wherein the elongated flexible locking member (30’) comprises an axial bore (44), whereby a fluid may be injected into the volume or volumes formed between the pin and box surfaces.2035011917Patentkrav1. Koblingsenhet for langstrakte elementer (1, 2), omfattende et tappelement (5) med en utovervendt tappoverflate (12), og et bokselement (6) med en innovervendt boksoverflate (13); nevnte tappoverflate og boksoverflate er konfigurert for5 sammenkobling, og tetninger (7, 8) på tappelementet (5) og/eller bokselementet (6) definerer et volum (V) mellom tappelementet (5) og bokselementet (6) når de er sammenkoblet;karakterisert ved- ett eller flere langstrakte, fleksible låseelementer (30; 30’), og10 - tappelementet (5) er utstyrt med ett eller flere første sirkulære og perifere, ikke-heliske spor (31), og- bokselementet (6) er utstyrt med et tilsvarende minst ett sirkulært og periferisk, ikkehelisk spor (32), og- bokselementet (6) er utstyrt med minst én innføringsåpning (35) som er innrettet med15 det minst ett andre sporet (32),- hvorved, når tapp- og bokstilkoblingen er utført, er et første spor (31) og et tilsvarende andre spor (32) innrettet og danner en sirkulær, ikke-helisk og periferisk kanal (41) utformet og dimensjonert for mottak av det langstrakte, fleksible låseelementet (30; 30’);20 hvori minst én boring (9) har en første åpning (9a) konfigurert for tilkobling til et reservoar for injeksjonsvæske (10) og en andre åpning (9b) som trenger gjennom tappoverflaten (12) eller boksoverflaten (13), hvorved en væske kan injiseres i nevnte volum (V) dannet mellom minst en del av en ytre tappoverflate (12) og en tilsvarende indre del av boksoverflaten (13).25 2. Koblingsenhet ifølge krav 1, hvori de sirkulære sporene er anordnet vinkelrett på en lengdeakse for boksen og tappen.3. Koblingsenhet ifølge krav 1 eller 2, hvori materialet i det langstrakte, fleksible låseelementet (30) har en høyere fasthet enn materialet i boksen og tappen.4. Koblingsenhet ifølge hvilket som helst av kravene 1–3, hvori det langstrakte,30 fleksible låseelementet (30) er en vaier eller en fleksibel stang.350119185. Koblingsenhet ifølge hvilket som helst av kravene 1–4, som videre omfatter en innføringsåpning (35) på bokselementet (6), hvilken innføringsåpning (35) er innrettet med kanalen dannet av de første og andre sporene (31, 32).6. Koblingsenhet ifølge hvilket som helst av kravene 1–6, hvori låseelementet (30)5 videre omfatter et festeelement (34).7. Koblingsenhet ifølge hvilket som helst av kravene 1–7, hvori bokselementet (6) omfatter en sliss (36) i nærheten av innføringsåpningen (35), hvilken sliss er konfigurert for mottak av et festeelement (34).8. Koblingsenhet ifølge hvilket som helst av kravene 1–8, hvori låseelementets10 lengde tilsvarer kanalens omkrets.9. Koblingsenhet ifølge hvilket som helst av kravene 1–9, hvori tappoverflaten (12) omfatter en flerhet av fremspringende tappdeler adskilt av innfelte tappdeler, og boksoverflaten (13) omfatter en flerhet av fremspringende boksdelene adskilt av innfelte boksdelene; og hvori en fremspringende tappdel er utformet og dimensjonert for å passe15 inn i en tiltenkt innfelt boksdel, og hvori en fremspringende boksdel er utformet og dimensjonert for å passe inn i en tiltenkt innfelt tappdel.10. Koblingsenhet ifølge hvilket som helst av kravene 1–10, hvori det langstrakte, fleksible låseelementet (30’) omfatter en aksial boring (44), hvorved en væske kan injiseres i volumet eller volumene dannet mellom tapp- og boksoverflatene.20
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Priority

No priority

Patent classes

IPC classesE21B 17/04E21B 17/042F16L 37/084F16L 37/12F16B 21/06F16L 21/08CPC classesE21B 17/04E21B 17/042F16L 37/084F16L 37/12F16B 21/06F16L 21/08

Citations

US 4491351 A (A)US 2015/0292274 A1 (A1)US 6981547 B2 (B2)US 6913293 B1 (B1)US 2003/0122373 A1 (A1)WO 2018/143819 A1 (A1)US 2458714 A (A)

Applicants, owners and inventors

Owners
Torsion Tool Company AS
Postboks 2557, Eiganes 4094 STAVANGER NO (STAVANGER Municipality, Rogaland county)Org. number: 998415373Inventors
Olav Olsen
Nedre Stokkavei 22 4023 STAVANGER NO (STAVANGER Municipality, Rogaland county)

Agent

ZACCO NORWAY AS
ZACCO NORWAY AS

Org. number: 982702887

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Postboks 488 0213 OSLO NO (OSLO Municipality, Oslo county)
Org. number: 982702887
Reference: P342024NO00

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