阅读说明：本技术 用于联结钻井的金属管形件的装置和方法 (Apparatus and method for joining metal tubular members for drilling ) 是由 G.皮纳雷多 A.百利尼 于 2018-02-13 设计创作，主要内容包括：一种用于联结待下降到井筒(4)中的金属井管形件的方法,包括以下步骤：a)提供具有上端部表面(6a)的第一井管形件(6)和具有下端部表面(7a)的第二井管形件(7)；b)将第一井管形件(6)下降到井筒(4)中,从而使其上端部留在井筒(4)外部；c)将第二井管形件(7)设置于第一井管形件(6)上的轴向对准位置中,其中第二井管形件(7)的下端部表面(7a)设置成紧靠第一井管形件(6)的上端部表面(6a)；d)将第一井管形件(6)和第二井管形件(7)保持在所述轴向对准位置中；e)将第一井管形件(6)的上端部焊接到第二井管形件(7)的下端部,从而在对应于所述上端部表面(6a)和所述下端部表面(7a)的位置中形成周向焊缝(WL)；以及f)将被焊接在一起的第一井管形件(6)和第二井管形件(7)下降到井筒(4)中。步骤e)包括以下的操作：-设置至少一个激光焊接头(13),其被配置成用于将激光束(LB)导引朝向周向工作区(WA),该周向工作区(WA)包括第一井管形件(6)的上端部部分和第二井管形件(7)的下端部部分,至少一个激光焊接头(13)可根据相应的旋转轨迹围绕周向工作区(WA)位移；-提供至少一个感应加热装置(141、142),其可基本上根据至少一个激光焊接头(13)的旋转轨迹位移,至少一个感应加热装置(141、142)参考至少一个激光焊接头(13)的旋转方向(R)分别设置在至少一个激光焊接头(13)的上游或下游；-导致至少一个激光焊接头(13)的旋转和至少一个感应加热装置(141、142)的旋转,使得-激光束(LB)逐步形成周向焊缝(WL)；以及-至少一个感应加热装置(141、142)分别在激光束(LB)到达周向工作区(WA)的对应的部分(PH、PH2)之前或在激光束(LB)已到达所述对应的部分(PH1、PH2)之后向所述对应的部分(PH1、PH2)供应热量,所述周向工作区(WA)的对应的部分(PH1、PH2)包括相应的第一和第二井管形件(6、7)的所述上和下端部部分的相应的部分。(A method for joining a metallic well tubular to be lowered into a wellbore (4) comprises the steps of a) providing a th well tubular (6) having an upper end surface (6 a) and a second well tubular (7) having a lower end surface (7 a), b) lowering the th well tubular (6) into the wellbore (4) so that its upper end remains outside the wellbore (4), c) placing the second well tubular (7) in an axially aligned position on the th well tubular (6), wherein the lower end surface (7 a) of the second well tubular (7) is placed in close proximity to the upper end surface (6 a) of the th well tubular (6) 2 th well tubular (6), d) holding the th well tubular (6) and the second well tubular (7) in said axially aligned position, e) welding the upper end portion of the th well tubular (6) to the upper end portion (7) of the second well tubular (7) according to a circumferential heat induction welding head (142) of the second well tubular (72) or at least one of a peripheral heat-inducing device (367) of the heat-generating laser beam (34) and heat-generating heat energy by rotating the peripheral heat-inducing devices (367) of the peripheral weld head (H) of the respective heat-generating devices (H-H.)

1, device for coupling well tubular metals to be lowered into a borehole (4), comprising a th well tubular (6), said th well tubular (6) being suspended in said borehole (4) in a substantially vertical position, wherein an upper end of said th well tubular (6) is outside said borehole (4), in particular in a position corresponding to a drilling floor (3), and a second well tubular (7), said second well tubular (7) being in a position which is substantially vertical and axially aligned above said th well tubular (6), wherein a lower end surface (7 a) of said second well tubular (7) is arranged in abutment against an upper end surface (6 a) of said th well tubular (6), wherein said device comprises:

-a welding arrangement (11), said welding arrangement (11) being for forming a circumferential Weld (WL) at said upper and lower end surfaces (6 a, 7 a) of a th and second well tubular (6, 7);

-a control arrangement (CU, UI),

wherein the welding arrangement (11) comprises a welding assembly (12), the welding assembly (12) comprising at least laser welding heads (13) and at least induction heating devices (14)₁、14₂），

Wherein the at least laser welding heads (13) are configured for directing a Laser Beam (LB) towards a circumferential Work Area (WA) comprising an upper end portion of the th well tubular (6) and a lower end portion of the second well tubular (7),

wherein the at least induction heating units (14)₁、14₂) Is prearranged for induction towards a corresponding portion (EW) of said peripheral Work Area (WA)₁、EW₂) Supplying heat, a corresponding portion (EW) of said peripheral Work Area (WA)₁、EW₂) Comprising respective parts of said upper and lower end parts of said second well tubular member (6, 7),

wherein the welding arrangement (11) further comprises a drive system (15, 16), the drive system (15, 16) being controllable for displacing the welding assembly (12) around the circumferential Work Area (WA) according to a respective rotational trajectory,

wherein the at least induction heating units (14)₁、14₂) Arranged in the welding assembly (12) upstream or downstream of the at least laser welding heads (13) with reference to the direction of rotation (R) of the welding assembly (12), respectively,

and wherein the control arrangement (CU, UI) is configured for controlling the welding assembly (12) and the drive system (15, 16) such that during rotation of the welding assembly (12),

-the Laser Beams (LB) emitted by the at least laser welding heads (13) step-wise forming the circumferential weld seam (WL), and

-said at least induction heating devices (14)₁、14₂) Respectively at the Portions (PH) where the Laser Beam (LB) reaches the circumferential Work Area (WA)₁、PH₂) Before or after the Laser Beam (LB) has reached the corresponding Portion (PH)₁、PH₂) Then to the corresponding Part (PH)₁、PH₂) Heat is supplied.

2. The apparatus of claim 1, wherein:

-the welding assembly (12) comprises an th induction heating device (14)₁) And a second induction heating device (14)₂) Said induction heating device (14) of the th₁) And the second induction heating device (14)₂) -being arranged upstream and downstream, respectively, of said at least laser welding heads (13) with reference to said direction of rotation (R) of said welding assembly (12);

-the control arrangement (CU, UI) is configured for controlling the welding assembly (12) and the drive system (15, 16) such that during rotation of the welding assembly (12):

-said th induction heating device (14)₁) At the th Part (PH) where the Laser Beam (LB) reaches the circumferential Work Area (WA)₁) Before the th Part (PH)₁) Supplying heat; and is

-said second induction heating means (14)₂) At the placeThe Laser Beam (LB) having reached a second Part (PH) of the circumferential Work Area (WA)₂) Then to the second Part (PH)₂) Heat is supplied.

3. The device according to claim 1 or claim 2, comprising at least laser radiation generators (LG) that are in a location remote from the welding component (12) and are connected to the at least laser welding heads (13) via optical fibers (13 a).

4. The device according to any of claims 1-3, further comprising a holding arrangement (9, 10; 17)₄、17₅) For blocking said th well tubular member (6) and said second well tubular member (7) in said axially aligned position.

5. Device according to , wherein the drive system (15, 16) comprises a substantially annular guide support (15), the guide support (15) being prearranged for receiving therethrough the th well tubular (6) and/or the second well tubular (7), the guide support (15) defining a guide identifying the rotation trajectory, the welding assembly (12) being coupled displaceably to the guide, in particular via or more rolling members (18 a, 18 b), there being a motor (16) preferably associated to at least of the welding assembly (12) and the guide support (15), the motor (16) being controllable for causing displacement of the welding assembly (12) along the guide.

6. The device of any of claims 1 to 5, wherein the welding assembly (12) has a respective structure (17), the respective structure (17) supporting the at least laser welding heads (13) and the at least induction heating devices (14)₁、14₂) -said respective structure (17) is shaped to surround at least parts of the circumference of said -th well tubular member (6) and/or said second well tubular member (7).

7. The device of any of claims 1-6, wherein the welding arrangement (11) is configured for enabling adjustment of the at least induction heating devices (14)₁、14₂) -an operating position relative to the th well tubular (6) and the second well tubular (7) and/or relative to the at least laser welding heads (13).

8. The device according to any of claims 1-7, wherein the control arrangement (CU, UI) is prearranged for enabling independent control of a plurality of induction heating devices (14) provided in the welding arrangement (11)₁、14₂）。

9. The apparatus according to any of claims 1-8, wherein the control arrangement (CU, UI) comprises at least Control Units (CU) and a User Interface (UI) for displaying and/or setting operating parameters, preferably comprising or more of:

-the power of the Laser Beam (LB),

-a displacement speed of the welding assembly (12),

-a depth of focus of the Laser Beam (LB),

-said at least induction heating devices (14)₁、14₂) The operating frequency of (a) is set,

-for supplying said at least induction heating means (14)₁、14₂) The intensity of the current of (a) is,

-said at least induction heating devices (14)₁、14₂) The order and/or duration of the on/off,

-said at least induction heating devices (14)₁、14₂) Relative to the radial position of the peripheral surfaces of the well tubular member (6) and the second well tubular member (7),

-said at least induction heating devices (14)₁、14₂) A distance from the at least laser weld heads (13) along a weld circumference.

10. The device of any of claims 1-9, wherein the at least induction heating devices include inductor windings that are supplied by means of at least transformers and at least power converters, the at least transformers and at least power converters being in a location remote from the welding arrangement (11).

11. The device of any of claims 1-10, wherein the welding arrangement (11) or the welding assembly (12) further includes at least of:

-another induction heating device (14)₃、14₄) Said another induction heating device (14)₃、14₄) Are respectively arranged at a higher or lower height than the laser welding head (13);

-a welding torch (21), said welding torch (21) being intended for welding at said upper and lower end surfaces (6 a, 7 a) of a respective th and second well tubular (6, 7) by adding material;

-means (20) for directing a gas flow substantially at a welding area reached by the Laser Beam (LB);

-a support (17 '), said support (17') being for said at least induction heating devices (14)₁、14₂) Said support (17') having a substantially annular shape, said at least laser welding heads (13) being preferably arranged at a central opening of said substantially annular shape.

12. The device according to of any one of claims 1 to 11, comprising a movable support structure (50) bearing at least the welding assembly (12), the support structure (50) being movable, in particular on a drilling floor (3), between a non-operating position, which is substantially at a distance of from the circumferential Work Area (WA), and an operating position, which is substantially close to the circumferential Work Area (WA), the support structure (50) preferably being designed to be mounted so as to be movable in a direction substantially perpendicular to an axis (X) of the wellbore (4).

13, a method for coupling well tubular metal elements to be lowered into a wellbore (4), comprising the steps of:

a) providing an th well tubular member (6) having an upper end surface (6 a) and a second well tubular member (7) having a lower end surface (7 a);

b) lowering the th well tubular (6) into the wellbore (4) leaving the upper end of the th well tubular (6) outside the wellbore (4);

c) -arranging the second well tubular (7) in an axially aligned position above the -th well tubular (6), wherein the lower end surface (7 a) of the second well tubular (7) abuts against the upper end surface (6 a) of the -th well tubular (6);

d) -holding the th well tubular member (6) and the second well tubular member (7) in the axially aligned position;

e) welding the upper end of the th well tubular (6) to the lower end of the second well tubular (7) forming a circumferential Weld (WL) at the upper end surface (6 a) and the lower end surface (7 a);

f) lowering the well tubular member (6) and the second well tubular member (7) welded onwards towards the inside of the wellbore (4),

wherein step e) comprises the following operations:

-providing at least laser welding heads (13), said at least laser welding heads (13) being configured for directing a Laser Beam (LB) towards a circumferential Work Area (WA), said circumferential Work Area (WA) comprising an upper end portion of said well tubular (6) and a lower end portion of said second well tubular (7), said at least laser welding heads (13) being displaceable around said circumferential Work Area (WA) according to respective rotational trajectories;

-providing at least induction heating units (14)₁、14₂) Said at least induction heating units (14)₁、14₂) Being displaceable substantially according to the rotational trajectory of the at least laser welding heads (13), the at least induction heating devices (14)₁、14₂) -being arranged upstream or downstream of said at least laser welding heads (13), respectively, with reference to the direction of rotation (R) of said at least laser welding heads (13);

-causing rotation of the at least laser welding heads (13) and the at least induction heating devices (14)₁、14₂) Such that:

-said Laser Beam (LB) forming said circumferential Weld (WL) step by step; and is

-said at least induction heating devices (14)₁、14₂) Respectively at the Portions (PH) where the Laser Beam (LB) reaches the circumferential Work Area (WA)₁、PH₂) Before or after the Laser Beam (LB) has reached the corresponding Portion (PH)₁、PH₂) Then to the corresponding Part (PH)₁、PH₂) Supplying heat, the corresponding Portion (PH) of the circumferential Work Area (WA)₁、PH₂) Comprising th and respective parts of said upper and lower end parts of the second well tubular member (6, 7).

14. The method of claim 13, wherein the at least induction heating devices (14)₁、14₂) Comprises an induction heating device (14) of the th₁) And a second induction heating device (14)₂) Said induction heating device (14) of the th₁) And the second induction heating device (14)₂) Both being rotatable substantially according to said rotation trajectory upstream and downstream of said at least laser welding heads (13), respectively, with reference to said rotation direction (R) of said at least laser welding heads (13), such that during rotation of said at least laser welding heads (13), said th induction heating device (14)₁) And the second induction heating device (14)₂）：

The th induction heating device (14)₁) At the th part (EW) where the Laser Beam (LB) reaches the circumferential Work Area (WA)₁) The th Part (PH) of the previous circumferential Working Area (WA)₁) Supplying heat; and is

The second induction heating device (14)₂) After the Laser Beam (LB) has reached a second portion (EW) of the circumferential Work Area (WA)₂) The second Part (PH) of the previously facing circumferential Work Area (WA)₂) Heat is supplied.

15. The method according to claim 13 or claim 14, wherein the at least induction heating devices (14)₁、14₂) Is rotationally fixed relative to the at least laser welding heads (13).

16, A device for coupling well tubulars to be lowered into a wellbore (4), the well tubulars comprising a th well tubular (6), the th well tubular (6) being suspended in the wellbore (4) in a substantially vertical position, wherein an upper end of the th well tubular (6) is outside the wellbore (4), in particular in a position corresponding to a drill floor (3), and a second well tubular (7), the second well tubular (7) being in a position which is substantially vertical and axially aligned above the th well tubular (6), wherein a lower end surface (7 a) of the second well tubular (7) abuts against an upper end surface (6 a) of the th well tubular (6), wherein the device comprises:

-a welding arrangement (11), said welding arrangement (11) being for forming a circumferential Weld (WL) in a position corresponding to said upper and lower end surfaces (6 a, 7 a) of the th and second well tubular members (6, 7),

-a control arrangement (CU, UI),

wherein the welding arrangement (11) comprises a welding assembly (12), the welding assembly (12) comprising at least laser welding heads (13),

wherein the at least laser welding heads (13) are configured for directing a Laser Beam (LB) towards a circumferential Work Area (WA) comprising an upper end portion of the th well tubular (6) and a lower end portion of the second well tubular (7),

wherein the welding arrangement (11) further comprises a drive system (15, 16), the drive system (15, 16) being controllable for displacing the welding assembly (12) around the circumferential Work Area (WA) according to a respective rotational trajectory,

wherein the control arrangement (CU, UI) is configured for controlling the welding assembly (12) and the drive system (15, 16) such that the Laser Beams (LB) emitted by the at least laser welding heads (13) gradually form the circumferential Weld (WL) during rotation of the welding assembly (12),

and wherein the apparatus further comprises a movable support structure (50) supporting at least the welding assembly (12), the support structure (50) being movable, in particular on a drilling floor (3), between a non-operative position and an operative position, which are substantially remote and substantially close, respectively, with respect to the circumferential Work Area (WA), the support structure (50) preferably being designed to be mounted movable in a direction substantially perpendicular with respect to the axis (X) of the wellbore (4).

17. Device according to claim 16, wherein the movable support structure (50) comprises a motorized vehicle, in particular provided with wheels or the like (51).

18. Apparatus according to claim 16 or claim 17, wherein the support structure (50) is prearranged to be mounted so as to be movable on a guide or rail (52) provided on a drilling floor (3) at which the opening of the wellbore (4) opens.

19. The device of any of claims 16 to 18, wherein the welding arrangement (11) includes at least induction heating devices (14)₁、14₂、14₃、14₄) Said at least induction heating units (14)₁、14₂、14₃、14₄) Is pre-arranged to inductively feed at least corresponding Parts (PH) of the upper end portion of the well tubular (6) and/or the lower end portion of the second well tubular (7)₁、PH₂) Supplying heat, wherein preferably:

-said at least induction heating devices (14)₁、14₂) Is prearranged to respond to a corresponding Portion (PH) of said circumferential Work Area (WA)₁、PH₂) Supplying heat, the corresponding Portion (PH) of the circumferential Work Area (WA)₁、PH₂) Comprising said th and said upper and lower end parts of the second well tubular member (6, 7), and

-said at least induction heating devices (14)₁、14₂) Arranged on the welding assembly (12) upstream or downstream of the at least laser welding heads (13) with reference to the direction of rotation (R) of the welding assembly (12), respectively,

such that during rotation of the welding assembly (12), the at least induction heating devices (14)₁、14₂) Respectively arrive at the Laser Beam (LB)Said corresponding Portion (PH) of said circumferential Work Area (WA)₁) Before or after the Laser Beam (LB) has reached the corresponding Portion (PH) of the circumferential Work Area (WA)₂) Then towards the corresponding Portion (PH) of the circumferential Work Area (WA)₁、PH₂) Heat is supplied.

20. The device of claim 19, wherein the at least induction heating units (14) are mounted on the movable support structure (50)₁、14₂、14₃、14₄) or more components of at least of the supply system and the cooling system of (a).

21. The apparatus of any of claims 16 to 20, wherein or more components of at least of the power system and cooling system of the at least laser welding head (13) are mounted on the movable support structure (50).

22. The device according to any of claims 16-21, further comprising a holding arrangement (9, 10; 17)₄、17₅) For blocking th well tubular member (6) and the second well tubular member (7) in the axially aligned position, the holding arrangement (9, 10; 17)₄、17₅) Comprises a holding means (9, 10), in particular a vice or a jaw element, said holding means (9, 10) being borne by said movable support structure (50) and being configured to assume a holding position and a release position in which said movable support structure (50) is displaceable between said inoperative position and said operative position.

23. The apparatus of any of claims 16-22, wherein:

-the drive system (15, 16) comprises a substantially annular guide support (15), the guide support (15) being prearranged for receiving therethrough the th well tubular (6) and/or the second well tubular (7), the guide support (15) defining a guide defining the rotation trajectory, the welding assembly (12) being displaceably coupled to the guide, in particular via or more rolling members (18 a, 18 b), there being a motor (16) preferably associated to at least of the welding assembly (12) and the guide support (15), the motor (16) being controllable to cause displacement of the welding assembly (12) along the guide,

-said guide support (15) comprises at least two guide portions (15 a, 15 b) that can be mutually coupled and are borne by said movable support structure (50), said at least two guide portions (15 a, 15 b) being configured to assume a closed position and an open position in which said movable support structure (50) can be displaced between said inoperative position and said operative position.

24. The apparatus of any of claims 16-23, wherein the movable support structure (50) has at least of:

-an identification system configured for locating the position of the upper end surface (6 a) of the -th well tubular (6) and the lower end surface (7 a) of the second well tubular (7),

-a system for measuring and/or controlling properties of the weld in real time.

25. Apparatus according to any of claims 16 to 24, comprising a control system for controlling at least the displacement of the movable support structure (50) between the inoperative position and the operative position.

26. The device of wherein at least laser radiation generators (LG) are in remote locations relative to the welding assembly (12) and are connected to the at least laser welding heads (13) via optical fibers (13 a).

27. The device of any of claims 16 to 26, wherein the welding assembly (12) has a respective structure (17) supporting the at least laser welding heads (13), the respective structure (17) being shaped to surround at least portions of a circumference of the th well tubular (6) and/or the second well tubular (7).

28. Apparatus according to claim 19 or claim 20, wherein

-the welding arrangement (11) is configured for enabling adjustment of the at least induction heating devices (14)₁、14₂) An operating position relative to the th well tubular (6) and the second well tubular (7) and/or relative to the at least laser welding heads (13), and/or

-the control arrangement (CU, UI) is prearranged for enabling control of a plurality of induction heating devices (14) provided in the welding arrangement (11) in an independent manner₁、14₂）。

29. Apparatus according to any of claims 16 to 28, wherein the control arrangement (CU, UI) comprises at least Control Units (CU) and a User Interface (UI) for displaying and/or setting operating parameters, preferably comprising or more of the following:

-the power of the Laser Beam (LB),

-a displacement speed of the welding assembly (12),

-a depth of focus of the Laser Beam (LB),

-at least induction heating devices (14) belonging to the welded assembly (12)₁、14₂) The operating frequency of (a) is set,

-supplying at least pertaining to said welded assembly (12)An induction heating device (14)₁、14₂) The intensity of the current of (a) is,

-at least induction heating devices (14) belonging to the welded assembly (12)₁、14₂) The order and/or duration of the on/off,

-at least induction heating devices (14) belonging to the welded assembly (12)₁、14₂) A radial position with respect to the peripheral surfaces of the well tubular members (6) and the second well tubular member (7),

-at least induction heating devices (14) belonging to the welded assembly (12)₁、14₂) A distance along the welding circumference relative to the at least laser welding heads (13).

30. The apparatus of any of claims 16 to 29, wherein the welding arrangement (11) or the welding assembly (12) further comprises at least from:

-another induction heating device (14)₃、14₄) Said another induction heating device (14)₃、14₄) Are respectively arranged at a higher or lower height than the laser welding head (13);

-a welding torch (21), said welding torch (21) being adapted to perform welding at said upper and lower end surfaces (6 a, 7 a) of said and second well tubular members (6, 7) by adding material;

-means (20) for directing a gas flow substantially at a welding zone reached by the Laser Beam (LB),

-at least induction heating devices (14) belonging to the welded assembly (12)₁、14₂) Said support (17') having a substantially annular shape, said at least laser welding heads (13) being preferably arranged in a position corresponding to a central opening of said substantially annular shape.

Technical Field

The present invention relates to the art of downhole drilling, such as wells for oil production, and has been developed with particular reference to the interconnection of metal tubular bodies for use in the construction of the aforementioned wells.

Background

The production well, in particular an oil well, is lowered from the process of drilling of the soil, with the aim of defining a substantially vertical wellbore, as the drilling progresses in depth, it is necessary to protect the upper part of the wellbore both from collapse of its peripheral wall and from possible infiltration of water and/or oil, as well as from the suction of drilling mud, this step, known as completion of the well, is carried out by lowering a number of metal tubular bodies of circular cross-section, usually made of steel, into the wellbore.

Subsequent drilling at greater and greater depths is carried out with even smaller sized percussion drill bits (chipelbits) so as not to damage the inner walls of the already laid tubular bodies. For this reason, the lining of the well formed by tubular bodies fixed to each other in the wellbore has an upwardly decreasing diameter, and the number of tubular elements to be lowered is limited due to the progressive narrowing of the well. The diameter of the tubular bodies typically ranges from 10 to 100 cm, and their wall thickness typically ranges from 8 to 25 mm.

Currently, the coupling of tubular elements is performed mechanically via threaded joints using of the following possible types of connections, short round and Collar (CSG), long round and collar (LCSG), buttress thread and collar (BCSG) and straight thread (XCSG), CSG, LCSG and BCSG types of connections use the additional length of tubular elements, commonly called "collar (coupling"), which are internally threaded and are coupled to the ends of two pipes to be joined starting at , which are externally threaded, the threads have a circular profile (CSG, LCSG) or a sawtooth profile (BCSG), instead, the XCSG connection is obtained by screwing together with a sawtooth profile the inner ends of tubular elements to be coupled starting at and the outer ends of another tubular elements, the inner ends of and the outer ends of the other tubular elements then being screwed directly to each other.

The technique of coupling of tubular bodies or sleeves based on mechanical coupling via threaded joints presents particular drawbacks.

First, the cost of well tubulars can be as high as 40% due to the complexity of the machining operations required for threading work, second, the presence of the end threads of the well tubulars complicates the operations of storage, transportation and laying of the tubulars themselves in view of the need to protect the threaded end of the well tubulars, and also, the operation of the coupling between the various well tubulars (i.e., the fact that they must be tightened at during laying) is complicated due to the large size of the body to be coupled up at .

EP 396204A discloses techniques for friction welding tubular bodies or casings for drilling, according to which a ring of welding material is provided between two ends of the tubular body to be joined at , which are vertically axially aligned on top of each other, the ring is rotated at high speed and deformed in a radial direction in order to generate sufficient heat to effect friction welding between the ring itself and the ends of the two tubular bodies.

From EP 958094 a is known techniques for induction welding tubular bodies for drilling wells, also in this case a welding ring is provided between the two ends of the tubular body to be joined from , which are aligned axially vertically on top of each other, the region of the joint between the two tubular bodies is enclosed in a gas-tight chamber into which an inert gas is injected, and an induction coil is provided in the chamber, which is designed to heat the material of the welding ring up to the melting point and thus create a metallurgical bond between the ends of the tubular bodies.

Disclosure of Invention

According to the present invention, this object is achieved by devices for coupling well tubulars having the characteristics specified in the appended claims.

As will become more apparent hereinafter, according to the th aspect, a laser beam is used to butt weld the well tubulars to obtain their mutual coupling by means of fusion and resolidification of the interface of the tubulars themselves in a preferred embodiment, the process of laser welding is assisted by heating by means of or more electromagnetic inductors arranged so as to lead and/or follow the point of incidence of the laser beam in the region of the weld joint with reference to the direction of travel of the weld point in this way or more inductors supply heat to the weld joint and/or the region surrounding the weld joint, thereby preventing it from cooling too quickly.

According to a second aspect, the welding device is supported by an structure mounted so as to be movable between a rest position, substantially at a distance of from the ends of the two tubular elements to be welded, and a working position, substantially close to the ends of the two tubular elements to be welded, the displacement of the movable structure preferably taking place in a guided manner in a direction substantially perpendicular to the axis of the wellbore.

Drawings

Further objects, characteristics and advantages of the present invention will emerge clearly from the detailed description that follows, with reference to the attached drawings, which are provided purely by way of non-limiting example, and in which:

FIG. 1 is a schematic front view of a device for coupling well tubulars according to a possible embodiment of the invention;

FIG. 2 is a detail of FIG. 1;

FIG. 3 is a schematic side view of two butt-coupled well tubulars, which is intended to illustrate the operating principle of the device according to a possible embodiment of the invention;

FIG. 4 is a schematic top plan view of a welding arrangement of a device according to a possible embodiment of the invention;

fig. 5 and 6 are schematic diagrams, respectively front and side views, of a welding arrangement of a device according to a possible embodiment of the invention;

FIG. 7 is a CCT (continuous cooling transition) plot comparing the cooling dynamics of a typical laser weld spot to that of a welding process followed according to an embodiment of the present invention;

FIG. 8 is a simplified block diagram of a possible control circuit of a welding arrangement of a device according to a possible embodiment of the present invention;

FIG. 9 is a partial and schematic side view of the device of FIG. 1, according to a possible advantageous embodiment;

fig. 10 and 11 are partial and schematic top plan views of a welding arrangement of a device according to a possible embodiment of the invention;

FIG. 12 is a view similar to that of FIG. 9 with respect to a further possible embodiment of the invention;

FIG. 13 is a view similar to that of FIG. 5 with respect to a possible variant embodiment of the invention;

FIG. 14 is a schematic front elevational view of elements of a welding arrangement of a device according to a possible embodiment of the invention;

FIG. 15 is a view similar to the view of FIG. 5 with a welding arrangement including the elements of FIG. 14;

FIG. 16 is a view similar to that of FIG. 5 with respect to another possible variant embodiment of the present invention;

fig. 17 is a view similar to that of fig. 4 with respect to another possible variant embodiment of the present invention.

Detailed Description

Furthermore, the particular configurations, structures, or characteristics defined herein may be combined in any suitable manner in or more embodiments, even differing from the embodied embodiments.

In the subsequent part of the present description, for the sake of simplicity, a so-called casing (i.e. a length or extension of a metal pipe used to form a liner of a wellbore, as explained in the introductory part) will be defined as "tubular" or "well tubular". It should also be noted that in the following only the elements useful for understanding the invention will be described, it being of course considered that the component parts (components) of the drilling system, such as the system for lifting, rotating and circulating, as well as the drill string, percussion drill head, etc., may be any concept known in the art.

Referring initially to fig. 1-3, according to a possible embodiment of the invention, designated as a whole by 1 is a device for coupling well tubular metal elements in various embodiments of the invention, the tubular elements to be coupled starting at are made of a steel alloy suitable for supporting chemical agents such as sulfuric acid (H) or the like₂S)) and mechanical properties (such as even slight earth movements). among the preferred materials for the purposes of the practice of the present invention, there may be included, for example, L80 and P101 steels, as well as the steels specifically mentioned in the standard API 5CT (American Petroleum institute Specification 5 CT) incorporated herein for reference.

In various embodiments, the apparatus 1 has a load bearing structure (designated as a whole by 2) that can be positioned on a drilling floor 3 having an opening in a position corresponding to the upper opening of a shaft 4 that is sunk in the soil and in which a plurality of metal tubulars are to be lowered, according to what has been described in the introductory part of the present description. Referring to the non-limiting example illustrated in FIG. 1:

designated by 5 is an th metal tubular element which has been fully inserted and suspended in the wellbore 4;

designated by 6 is a second tubular element partially inserted and suspended in the wellbore 4, the lower end of which is butt-welded to the upper end of the tubular element 5 via a circumferential weld WL; and is

Designated by 7 is a third tubular whose lower end surface 7a is to be butt-welded to the upper end surface 6a of the tubular 6 via a corresponding circumferential weld, which is then to be lowered into the wellbore 4 in a position embodied for the tubular 6.

As already mentioned, when the well tubular is to be installed in the wellbore 3, it is necessary to connect the tubulars themselves in series with each other to form a string of tubulars by an operation of connection performed in a zone located slightly above the rig floor 3 the process starts by lowering th tubular (e.g. tubular 5) into the wellbore 4 (e.g. using a hoisting system) and suspending it with respect to the rig floor 3 by means of temporary holding means, next secured to the upper end of the th tubular is the lower end of the second tubular (e.g. tubular 6) and lowering the thus formed string into the wellbore 3 using the hoisting system and then suspending it again, with the upper end portion of the second tubular protruding slightly above the rig floor 3, next secured to the upper end of the second tubular (e.g. end 6a of tubular 6) is the lower end of the third tubular (e.g. tubular 7 a), wherein the string is then suspended again for connection until the desired length of the string is obtained in the same way .

To enable these operations, it is therefore necessary to suspend temporarily at the level of the rig floor 3 using the mentioned holding means whenever a tubular or series of tubulars has been joined at (e.g. tubulars 5 and 6.) for example, such means may be of the type comprising purposely provided wedges (called "slips"), only some of which are represented in the figure, where the wedges are designated by CS. the slips arranged to form the openable collars are essentially metal sections, the outer profile of which has an approximately frusto-conical shape, and the inner profile of which is shaped (e.g. via teeth or combs) for gripping tubulars that are now protruding from the opening of the wellbore 4. the slips of the collars are positioned manually or via an actuator system at the opening in the rig floor 3, where the inner profile of which abuts against the outer surface of the discussed string.

Consistent with the present invention, two consecutive tubulars that will form part of the liner of a well are preferably positioned against each other end to end using a retention arrangement or system that is pre-arranged for ensuring concentricity and axial positioning between the tubulars themselves so as to limit the formation of gaps or any excessive misalignment, thereby ensuring a maximum interface between the end surfaces to be joined up at .

According to the preceding aspect, the welding assembly comprises, in addition to the laser head, at least heating inductors, such as of the pre-heating and post-heating inductors, wherein the or each inductor is movable along the circumference followed by the laser head, for example to the right and/or to the left of the head itself.

In various embodiments, structure 2 of apparatus 1 comprises a holding or centering arrangement configured for holding or blocking the tubular piece to be welded in its axially aligned position, ensuring its concentricity, preferably this arrangement comprises at least the th and second holding means, said th and second holding means being prearranged for blocking tubular piece 6 and tubular piece 7, respectively, in the aforementioned axially aligned position after lower end surface 7a of tubular piece 7 has been set in abutment against upper end surface 6a of tubular piece 6.

In the non-limiting example illustrated, the structure 2 comprises a substantially vertical upright, designated by 8, which supports the third and second retaining members 9, 10, for example vice or jaw members, at different heights, preferably the retaining members 9 and 10 are associated to corresponding controllable (electric or hydraulic or pneumatic) actuating systems and are able to assume corresponding operating and non-operating positions for blocking the tubulars 6, 7 in position, for releasing them after the tubulars 6, 7 have been butt-welded and thus enabling them to be lowered into the wellbore 4, as previously described, with the aid of the above-mentioned slip device CS, the movement of the upper tubular 7 in a device and manner known per se (for example, schematically embodied and designated by the industry lifting system or winch) is carried out to a vertical position (in which the upper tubular 7 is disposed on top of the tubular 6) and the subsequent lowering of the columns of the tubulars 5, 6 and 7.

The apparatus 1 further comprises a welding arrangement (designated as a whole by 11) configured for forming a circumferential weld WL joining the various tubular elements to be lowered into the wellbore 4 (i.e. with reference to the illustrated case, such weld is also formed at the upper end surface 6a and lower end surface 7a of the tubular elements 6 and 7, respectively).

In a preferred embodiment, the welding arrangement 11 comprises a movable welding assembly (designated as a whole by 12 in FIG. 2) comprising at least laser welding heads 13. As mentioned, according to the aspect, the welding assembly may also comprise at least induction heating devices 14. the assembly 12 is movable in the sense that it is mounted so that it can rotate in a controlled manner about a circumferential working zone comprising the upper and lower end portions of the two tubular members 6 and 7 to be joined at , which working zone is designated as a whole by WA in FIG. 3.

The welding arrangement 11 further comprises a drive system that can be controlled for displacing the welding assembly 12 around the work area WA according to a respective circular path or rotational trajectory. In various embodiments, the drive system comprises a guide support 15 for the assembly 12 and motor means 16 suitable for causing the displacement of the welding assembly 12 on the support 15.

As illustrated in fig. 4-6 (in which only the welding arrangement 11 is schematically embodied), in various preferred embodiments, the welding assembly 11 includes only laser welding heads 13 and 14₁And 14₂Two induction heating units (hereinafter defined as "inductors" for simplicity) are indicated.

In various embodiments, the laser welding head 13 is prearranged for focusing the power laser beam at a distance substantially comprised between 10 and 50 cm with respect to the surface to be treated. The head 13 is connected via an optical fiber 13a (fig. 4) to a generator of laser radiation (designated by LG in fig. 8), for example a fiber laser or a disk laser generator with modulatable power preferably between 5 and 40 kW. According to a technique known per se, the welding head 13 preferably comprises its own focusing system, which can be controlled.

It is also possible to construct electric inductors or a plurality of electric inductors 14 possibly used according to techniques known per se₁And 14₂And the electric inductor comprises an inductor winding supplied, for example, by several sets of power transformers and converters.

Preferably, the laser welding head 13 and possibly at least inductors 14₁And/or 14₂Supported by the same displaceable structures (indicated as a whole by 17 in figures 5 to 6)The displacement structure is for example a metal frame. In the non-limiting example illustrated, the structure 17 comprises an upper metal plate 17₁And a lower metal plate 17₂Fixed to said upper metal plate 17₁And a lower metal plate 17₂In between is a laser welding head 13 and each inductor 14₁And/or 14₂. Obviously, the structure 17 can be constructed in a manner different from what has been illustrated.

The laser welding head 13 is prearranged for directing a laser beam LB (FIG. 4) towards the circumferential work area WA, in particular in a position corresponding to the surfaces 6a, 7a being set in abutment against each other, when it is envisaged, at least inductors 14₁And/or 14₂Is prearranged for passing through a corresponding electromagnetic induction field EW₁And/or EW₂(fig. 4) heat is supplied to the corresponding portion of work area WA (i.e. to both tubular members 6 and 7 in the example considered here).

In accordance with the foregoing aspect , at least inductors 14₁And/or 14₂Is provided so that the direction of rotation of the reference assembly 12 (i.e., the direction in which the laser welding travels) moves either upstream (i.e., leading) or downstream (i.e., following) of the laser welding head 13. In the illustrated case and with reference to fig. 4 (in which the direction of rotation of the assembly is counter-clockwise, as indicated by arrow R), the inductor 14₁And 14₂And therefore upstream (leading) and downstream (following) of the laser head 13, respectively, for this purpose, in the example illustrated at least inductors are rotationally fixed with respect to the head 13, i.e. it is mounted on the same assemblies or units 12, together with the welding head 13 .

The control system of the apparatus 1 forming the subject of the invention is configured for controlling the welding arrangement 11, in particular the welding assembly 12 and its drive systems 15 to 16, in such a way that, after rotation of the assembly 12 around the ends of the tubular elements 6, 7 to be joined starting from :

the laser beam LB emitted by the head 13 develops the corresponding weld WL and, if laser welding is assisted by electromagnetic induction,

-from at least inductors 14₁And/or 14₂Preferably, as already mentioned, the inductors or multiple inductors are not moved in an independent manner, but are rotationally fixed with the laser head so as to ensure the same distribution of the supply of heat at each point of the welded joint.

In order to better clarify the concept of laser welding assisted by electromagnetic induction, reference may be made to fig. 3, wherein for the sake of clarity an embodiment of the device according to the invention has been omitted. In this figure WA indicates the above mentioned working area or zone, comprising the ends of tubular elements 6 and 7 arranged in abutment with each other, wherein the corresponding surfaces 6a and 7a are substantially in contact with each other. In applications of the type illustrated, the surfaces 6a and 7a are preferably machined so as to present flat edges in order to maximize the interface area between the ends of the tubular elements 6 and 7.

The welding assembly 12 is rotated substantially about the axis X (fig. 4) of the two tubular elements axially aligned on each other (i.e. the axis of the wellbore 4), so that the laser beam LB, which is focused according to techniques known per se, develops a weld LW in a position corresponding to the surfaces 6a, 7 a. During the course of rotation of the assembly 12, the inductor 14 is positioned before the laser beam impinges on a particular portion of the work area WA to form a weld at the surfaces 6a, 7a₁Heating (preheating) this particular part of the working area WA (schematically represented in FIG. 3 and indicated by PH)₁Indicated). At the same time, the inductor 14₂Another parts (schematically represented in FIG. 3 and represented by PH) of the heated (post-heated) work area WA₂Mark) on which the laser beam LB has been irradiated. Of course, fig. 3 illustrates static conditions such that it will be assumed that: in fact, the beam LB and the inductively heated region PH₁And pH₂Continuously displaced towards the right as viewed in the figure, and also the weld WL is "lengthened" stepwise towards the right.

The presence of the or each inductor enables the supply of heat to the weld joint to be controlled so as to prevent it from cooling too quickly. The laser welding used according to the invention in fact guarantees a high supply of heat in a small area of the material comprising the melting zone, compared to conventional arc welding techniques. As the laser beam LB advances along the joint, the molten bath cools rapidly, transferring energy to the two tubular members 6, 7 by conduction. Therefore, if subjected to stress, the presence of a microstructure different from that of the base material (base material) and having different mechanical properties can therefore lead to phenomena of cracking and brittle fracture. For this reason, according to a preferred embodiment of the invention, the laser welding can be assisted by a system for supplying heat by induction, which enables heating of the area of the tubular element close to the welding area; in this way, the cooling of the weld zone is slowed down by the presence of the surrounding thermal pool and occurs in a more gradual manner, counteracting the formation of undesirable metallurgical phases.

The CCT diagram of FIG. 7 shows the relationship between cooling rate over a specific temperature range and microstructure for common steel origins it should be noted that the diagram only represents the phenomenon of microstructure transformation occurring in the steel during cooling and is not intended to be exhaustive for all existing types of steel the curve designated by I represents typical cooling kinetics after classical laser welding.instead the curve designated by II represents the cooling curve in an induction assisted process as in the previously described preferred embodiment of the invention As may be noted in the case of curve I there is rapid cooling of the material after welding between points A and B.after this cooling the material may exhibit a high proportion of microstructures with high hardness and thus exhibit brittle behaviour.in addition , in the case of curve II there is an extension from A 'to B' representing a mild cooling supported by using an inductor which heats the metallic material before and/or after laser welding. emphasizes that there is a return to a faster cooling curve as there is a return of heat by induction, as there is a mechanical load that can withstand after this cooling of the material in situ.

FIGS. 4 to 6 are welds made only by FIG. 1 and FIG. 2A schematic illustration is provided of an example of a possible configuration of the welding arrangement 11. Structure 17 of the welding assembly 12 (in this case, associated to the structure 17 are the laser welding head 13 and inductor or inductors 14₁And/or 14₂) Preferably having a substantially semi-circular shape, or in any case being equipped to follow the zone to be welded rotatably around at least portions of the circumference of the tubular pieces 6, 7 in the work area WA (fig. 3), so that the laser head and at least inductors, the structure 17 is therefore arranged rotatably substantially centred on the axis X of fig. 4, preferably the rotary movement of the structure 17 is guided by means of a guide support 15, said guide support 15 having, in this example, a substantially circular shape and surrounding the tubular pieces 6, 7, the guide support 15, which is supported, for example, by means of the load-bearing structure 2 itself of the device 1, may be equipped with an articulated joint or coupling enabling its opening along its circumference and its positioning around the tubular pieces 6, 7.

Associated to the structure 17 or to the guide support 15 are motor means which can be controlled for causing the movement of the former along the circular path defined by the latter. In the non-limiting example illustrated, associated to the structure 17 is, for example, an electric motor 16, the electric motor 16 being designed to cause the rotation of a rolling member 18a, the rolling member 18a being engaged in a corresponding guide defined by the support 15. The member 18a may be a motor-driven gear engaged in a rack having an annular development defining a circular path for movement of the welding assembly 12. The structure 17 may comprise further elements for coupling to the guide support 15, such as a post 17₃ Said upright column 17₃To of the plates of structure 17 and bearing respective rolling members 18b mounted idle and engaged in an annular guide defined by support 15.

In the illustrated case, the guide structure 15 is positioned below the welding joint, i.e. below the end surfaces 6a, 7a of the tubular elements 6, 7: clearly, however, it can be positioned above said surfaces 6a, 7a so as to support the assembly 11 from above in a substantially suspended condition. According to other embodiments, the guide structure 15 may be prearranged to have portions extending below and above the surfaces 6a, 7a, respectively (for example, associated to the outer surfaces of the tubular elements 6, 7), so as to obtain a more stable configuration.

The laser radiation is generated by means of a known laser generator (designated by LG in fig. 8, for example a fiber laser generator or a disc laser generator) and is conveyed to the welding head 13 via an optical fiber (also designated by 13a in fig. 4) in this way the generator LG can be located in a remote position from the laser welding head 13 and , in general even a few tens of meters from the welding arrangement 11, enabling the assembly 12 to rotate in any case₁And/or 14₂Connected to the corresponding supply system by means of a cable of sufficient length and supported/guided in a suitable manner to enable rotation of the assembly 12.

In various embodiments, such as embodied in FIG. 8, each inductor 14₁And/or 14₂By means of suitable lines 14a₁And/or 14a₂Coupled to corresponding transformers TR₁And/or TR₂Said transformer TR₁And/or TR₂In turn by means of a cable 14b₁And 14b₂(e.g. coaxial cable) to a corresponding power converter PC₁And/or PC₂In this case too, the possibility of positioning at least the part of the induction system in a position remote from the welding arrangement 11 enables greater flexibility of the process and simplifies the in-situ installation of the device 1.

Fig. 8 also illustrates, in simplified form, a possible control architecture of the device 1 according to the invention. In the figure, designated by CU is a control unit of the device (preferably a control unit equipped with a microprocessor) in which the control logic of the device 1 is implemented. Connected to the unit CU is a suitable user interface UI (for example, a touch-screen type user interface) for displaying and setting the operating parameters of the process.

The unit CU is prearranged for controlling the generator LG of the laser radiation, which, as already said, is conveyed to the laser welding head 13 via the optical fiber 13 a. The unit CU is also prearranged, via suitable lines 16a, for controlling the motor means 16 determining the rotation of the assembly 12 and possibly for controlling each power converter PC₁And/or PC₂Said power converter PC₁And/or PC₂Via corresponding transformer blocks TR₁And/or TR₂To realize a corresponding inductor 14₁And/or 14₂The supply of (2). In various embodiments, the unit CU is also prearranged for controlling the holding systems 9 and 10 (when these holding systems 9 and 10 are of the motor-driven and controllable type). In various embodiments, the portions 15a and 15b of the guide support are also movable between their closed position (see, for example, fig. 1 and 4) and the respective open position (see, for example, fig. 10 and 11) via a controllable (electric or hydraulic or pneumatic) actuation system: such an actuation system can also be controlled by means of the unit CU.

In various embodiments, the structure 17 and/or the guide support 15 are prearranged for enabling adjustment of each inductor 14₁And/or 14₂Relative to the tubular to be welded and/or relative to the laser welding head 13. In various embodiments, for example, it is envisaged to adjust the radial position of each inductor, i.e. its distance from the outer surface of tubular elements 6 and 7, which is proportional to the heating efficiency. Additionally or in combination, in various embodiments, it is envisaged to regulate each inductor 14₁And/or 14₂The position along the welding circumference, i.e. its distance from the laser head 13, has an influence on the heating kinetics of the tubular pieces 6, 7 in the area of the work area WA. The control of these positions may be of the manual type, for exampleAs obtained by mounting each inductor on assembly 12 via a corresponding support that can be manually adjusted in spatial directions or more, or these supports can be motor-driven and controlled via unit CU and interface UI.

The parameters relating to the welding that can be controlled via the interface UI may preferentially comprise the power of the laser beam, the displacement speed of the head 13 (i.e. of the assembly 12) and the depth of focus of the laser beam, which may preferentially be selected on the interface UI on the basis of the physical properties of the material of the tubular to be welded and the thickness of the tubular to be welded.

The welding can be carried out using a single laser beam LB, or using a laser beam optically split into two laser beams downstream of a collimator equipped with a head 13, or again using even a plurality of laser beams with different powers the welding assembly 12 can comprise even more than laser heads 13 for this purpose the or each laser beam can be perpendicular to the surface of the tubular to be welded, or describe the angle with respect thereto in three dimensions.

As in the example represented in the figures, the welding system can be configured so that the laser beam LB follows a rectilinear path of the welded joint (i.e. the outer contour of the surfaces 6a, 7 a), but in a possible variant embodiment the welding can be carried out by defining a pattern around the joint with a periodicity (laser oscillation) of for these cases, on the structure 17 of the welding assembly 12, it is possible to provide the laser head 13 or its focusing system managed by the unit CU with a suitable controllable movement system, a concept known per se.

According to a possible embodiment, the welding assembly 12 may be equipped with an optical system for tracking the welding joint (e.g., based on the use of at least cameras) for real-time monitoring and possibly correcting the path of the laser beam.

In terms of possible supply of additional heat, in various embodiments the control unit CU is prearranged for enabling the control of each inductor in an independent manner, so as to generate a heat supply profile that will enable obtaining a given metallurgical composition of the welding joint based on the desired process parameters and on the characteristics of the joint itself. Preferentially, the parameters of the process that can be changed for controlling the induction heating, e.g. via the interface UI, are as follows:

operating frequency, which determines the depth of penetration of the electromagnetic field and therefore the depth of induction current generated causing heating of the tubular element: by reducing the frequency, the depth of penetration is increased at the expense of an increase in the system (in particular, the power converter PC)₁And/or PC₂Of) size and reduced efficiency; for the purpose of practicing the invention, for each inductor 14₁And/or 14₂Preferred operating frequencies of (a) are comprised between 5 and 25 kHz;

current, its intensity and induction field EW₁And/or EW₂Is directly proportional and therefore correlates with an increase in temperature; for practical purposes, the desired current level is substantially determined for each inductor 14₁And/or 14₂A selected number of turns;

the sequence and duration of ON/OFF (ON/OFF) of each inductor, in the presence of numbers of inductors, it is preferable to be able to control each of them independently, in order to guarantee that each point of the joint has as identical a thermal profile as possible.

As already mentioned, in the case of inductors mounted on the assembly via respective adjustable motor-driven supports, their radial position and/or their distance from the laser head along the welding circumference can also be controlled via the unit CU and/or the interface UI.

In line with the aforementioned second aspect, the welding device is supported by a structure mounted so as to be displaceable between a non-operative or rest position, substantially distant from or at a distance from the ends of the two tubular pieces to be welded, and an operative or working position, substantially close to the ends of the two tubular pieces to be welded (i.e. close to the opening in the drilling floor 3), the aforementioned displaceable structure, preferably of the motor-driven type, can be mounted so as to be movable on guides or rails provided on the drilling floor 3, or even so as to be freely movable on wheels or the like directly on the drilling floor 3.

For example, the apparatus 1 previously described with reference to fig. 1 to 6 and 8 is supported by a movable structure, as schematically illustrated in fig. 9. In this figure, the aforementioned movable structure, here in its operating position, is substantially configured as a vehicle (designated as a whole by 50) provided with its own wheels 51. As mentioned, the wheels 51 may engage on corresponding guides or rails 52 fixed to the drilling floor 3, so as to define the path of movement of the vehicle itself between the respective rest and working positions: for this purpose, the vehicle 50 is preferably equipped with its own motor appliance. The displacement of the vehicle 50 preferably takes place in a direction substantially perpendicular to the axis X of the wellbore 4 (i.e. of the tubular to be butt-welded).

In the case illustrated in fig. 9, the vehicle 50 is provided with substantially parallel arms ( of which are designated by 53 in fig. 9), each of which supports a column 8, or in any case a corresponding holding means 9, 10 (which, as already said, may be a vice or a jaw element, for example), and preferably a respective portion 15a or 15b of the guide support 15 for the welding assembly 12. the arm 53 is displaceable between an open position (visible in fig. 10, for example) in which the respective portion of the holding means 10, 11 and the two guide portions 15a and 15b for the welding assembly 12 are sufficiently far apart from one another to enable the vehicle 50 to be displaced between a rest position and a working position, and a closed position (such as the closed position schematically represented in fig. 4), the arm 53 then being able to be brought into the closed position when the vehicle is in its working position (as in fig. 9), in which the holding means 9, 10 will hold the tubular 6, 7 and in which the two guide portions 15a block the welding area completely as previously described.

In the case illustrated in FIG. 10, the arms 53 are angularly movable between an open position and a closed position, as indicated by arrow "r". It another aspect, in various embodiments, the arms 53 may be linearly movable between the aforementioned positions, as indicated by arrow "a" in FIG. 11.

Preferably, the arm 53 or a similar structure performing its function can be displaced by means of a suitable controllable actuation system AS (for example of the electric, hydraulic or pneumatic type) provided on the vehicle 50. In various embodiments, the actuation system AS of the arm 53 is also envisaged for effecting displacements in height of the arm, such AS a fork-lift truck (fork-lift truck).

In various embodiments, the vehicle 50 is provided with an identification system to identify the location of the weld joint (i.e., the abutting ends 6a, 7a of the tubular to be joined at .) such a system may be based, for example, on the use of optical sensors or the use of positioning lasers or the use of camera-based systems to properly position the welding arrangement relative to the joint.

The vehicle 50 is preferably equipped with drive logic, which may be autonomous, supervised or remote. In the case of autonomous logic, the displacement of the vehicle 50 is programmed and managed by a controller (for example, the control unit CU itself of fig. 8) so as to perform at least the operation of displacement and the operation of positioning and opening/closing of the arm 53 in a fully automatic manner. Also, in the case of supervised logic, the vehicle 50 is programmed for autonomously performing its own operations, so as to (however, if necessary) effect interventions by the operator, for example by acting on the interface UI of fig. 8. In the case of remote logic, the vehicle 50 is instead remotely guided and/or controlled by an operator.

Advantageously, at least parts of the power electronics can be mounted on the vehicle 50 for the laser head (such as the generator LG of the laser radiation) and/or, if an induction system is envisaged, for the induction system (such as for example withAt least inductors 14₁And/or 14₂Of the supply transformer TR₁And/or TR₂) A system for cooling the laser head and/or a system for cooling at least inductors and/or a system for measuring/controlling the quality of the welding joint in real time (such as the aforementioned optical joint tracking system and/or the aforementioned system for monitoring the welding process) can also be installed on the vehicle 50.

It will be understood that the configuration of the vehicle 50 or other movable structure may be different from that previously exemplified, while ensuring its function of movement of the device 1 according to the invention. For example, it should be noted that in a possible embodiment, the system for supporting the holding means 9, 10 and the system for supporting the guide portions 15a, 15b for the welding assembly 11 can be controlled and/or driven in an independent manner. This situation is illustrated in fig. 12, in which the vehicle 50 (embodied in its non-operating or rest position) comprises two arms 53 for supporting and moving respective portions of the holding appliance 9, 10₁(only of which are visible) and two arms 53 for supporting and moving the respective guide portion 15a or 15b₂(only of which are visible.) also in this type of embodiment, the arms 53₁And/or 53₂Preferably by a corresponding actuation system.

The vehicle 50 or other movable structure performing its functions can be used in all embodiments described herein.

The characteristics of the invention emerge clearly from the foregoing description, as do the advantages thereof, which are mainly reflected by:

the process time is shorter or in any case comparable to that of the traditional fixing by screwing of the tubular piece to be joined from ;

the elimination of the threading process and of the threading itself, which involves both a reduction in costs and in machining times, and a reduction in procedures for protecting the threading, which are also expensive and complex;

increased safety, provided that the discontinuity constituted by the thread is removed and replaced by a welded joint capable of having mechanical properties perfectly similar to those of the parent metal;

the construction of the welding arrangement is simple and the overall dimensions are reduced.

The welding device according to the aforementioned second aspect can be easily positioned at the opening in the drilling floor, thus simplifying its displacement, thanks to the structure or vehicle that supports the device itself in a movable manner, which may possibly be controlled in an automatic and/or synchronized manner with respect to other operations carried out in the process of laying the well tubular, this advantage may be further increased thanks to the implementation of a corresponding control system that may be in a position that is originally away from the welding assembly, furthermore, when envisaged, the part of the control component can be carried by the aforementioned vehicle or movable structure.

It will be clear to a person skilled in the art that many variations are possible to the apparatus and method described herein, by way of example, without thereby departing from the scope of the invention as defined in the appended claims.

Additionally or alternatively, a gas stream may be provided for suppressing the plasma generated by the laser beam, which ionizes the air surrounding the weld, thus reducing the transmission efficiency, given that the plasma is able to absorb portions of the energy of the beam, a nozzle for the aforementioned inert gas stream or for the aforementioned gas stream used to suppress the plasma is only schematically represented in fig. 4, which is designated by 20 in fig. 4.

According to possible variant embodiments, except for the inductor 14₁And/or 14₂External or as inductor 14₁And/or 14₂Alternatively, the welding group 12 comprises at least inductors arranged above or below the laser head 13, so as to supply mainly only of the two tubular pieces to be weldedAt least inductors 14 have been provided, for example, to enable simultaneous heating of the parts of interest of the two tubular pieces to be welded in any case₁And/or 14₂However, the use of at least additional inductors for heating the respective tubular pieces helps to slow down the step cooling of the tubular piece in question after the passage of the laser beam for tubular pieces of large thickness (e.g., greater than 10 mm). from this point of view, it may therefore prove useful to provide another inductor higher than the joint and another inductor lower than the joint in order to locally heat the two tubular pieces to be joined , this case being illustrated in FIG. 13 by 14₃And 14₄Indicated are two further inductors which are arranged on the structure 17 above and below the laser head 13, respectively. Has previously been related to inductor 14₁And/or 14₂The same applies to the inductor 14₃And/or 14₄。

In an advantageous embodiment, the structure supporting the inductors or inductors provided has an overall annular shape with the weld head preferentially disposed at the central opening of the shape.

This is illustrated in fig. 14, in which the structure 17 of the welding assembly 12 comprises an annular body 17 ', which annular body 17' supports the inductor 14₁And 14₂And an inductor 14₃And 14₄These inductors are similar in function to the inductor described with reference to fig. 13. Obviously, an inductor 14 may also be provided₁And 14₂And/or inductor 14₃And 14₄Only mounted at the through opening of the annular body 17 'are welding heads 13, which welding heads 13 can be supported directly by the body 17' or (as illustrated in fig. 15) by other elements of the structure 17.

The solutions illustrated in fig. 14 and 15 may be implemented in all embodiments described hereinThe same type of solution, using the inductor 14, is also possible₁And 14₂And/or inductor 14₃And 14₄Only of them.

According to further possible variant embodiments, it is also possible to envisage adding material in order to increase the filling of the joint and to counteract the effect of undesired gaps between the surfaces 6a, 7a, due to, for example, non-optimal machining of the edges (i.e. the end surfaces 6a, 7 a).

The addition of material may be done by cold wire, i.e. without the application of heat, in which case a metal wire (e.g. steel wire) is placed in a position corresponding to the outer contour of the joint so as to be melted together with its by the laser beam LB.

Another possible configurations are represented schematically in FIG. 16, according to which it is envisaged to add welding material by using a welding torch 21 equipped with a corresponding distributor for bringing the metal wire to the joint according to techniques known per se, the welding torch 21 also enables the supply of additional heat in addition to that of the laser light emitted by the welding head 13, and enables the supply of material to fill any possible gaps or misalignments, of course, also in the case of FIG. 16, at least inductors, such as the inductor designated by 14 and/or the inductor above or below the head 13, can be envisaged in a similar manner to that explained above in relation to FIG. 13 and/or FIG. 14.

With reference to the two variants just described, in the case of using welding wire as additional welding material, it is advantageous to machine the end surfaces 6a, 7a of the tubular elements 6, 7 so as to define between them a groove on the outside, so that when the tubular elements themselves are positioned edge to edge, the joint presents substantially V-shaped seats for receiving the welding wire.

Fig. 17 illustrates, in a view similar to that of fig. 4, another possible embodiment according to which structure 17 of assembly 12 comprises a plurality of portions hinged to one another by means of hinged joints or the like so as to enable the operating configuration of the assembly itselfWhich can be adapted to the different diameters of the tubular pieces to be welded , in the illustrated example, there are provided at least central portions 17a, to which are associated at least central portions 17a laser welding heads 13, and at least two lateral portions 17b and 17c, to which are associated inductors 14, respectively, 17b and 17c₁And 14₂As will be appreciated, by varying the angular position of the portions 17b and 17c relative to the portion 17a, the same assembly 12 can be used in combination with tubular members of different sizes ranging between a maximum diameter and a minimum diameter, and also without the illustrated or two inductors.

Fig. 18 illustrates a further variant, according to which the guide structure 15 of the assembly 12 is prearranged for having a guide portion (here only the portion 15)₁Visible) which extend below and above the surfaces 6a, 7a, respectively. In this type of embodiment, the structure 17 may advantageously comprise a support portion (such as, for example, made of 17)₄And 17₅Designated support portions) designed to be temporarily associated to the outer surface of the tubular elements 6, 7 to be welded, in order to obtain a more stable configuration and/or blocking of the tubular elements in the axially aligned position. Of course, also in this type of embodiment, a vehicle of the type previously indicated by 50 may be used.

The envisaged laser heads 13 and inductors or multiple inductors can belong to different subassemblies of the welding assembly, at least of which are motor-driven, each subassembly having its own movable structure on the guide support 15 or on the respective guide support 15 defining the necessary rotation trajectory around the welding area.