Safety device for attaching to a pipe string comprising a plurality of connected pipe sections

Abstract

A safety device (20) for attaching to a pipe string (10) comprising a plurality of connected pipe sections (12). The device is configured, comprises a support structure (22) and a clamping arrangement (24) comprising a first engagement member (32) and a second engagement member (34), which clamping arrangement (24) comprises a disengaged state and an engaged state. The support structure comprises a recess (30) adapted to receive the envelope surface of the pipe section. The first engagement member and the second engagement member are arranged in different parts of the recess so that opposite sides of the pipe section are clamped between the first engagement member and the second engagement member when the clamping arrangement is in the engaged state.

Claims

1. A safety system for a pipe string, the safety system comprising: a safety device configured to attach to a pipe string, with the pipe string comprising a plurality of connected pipe sections; an assembly of wedged slips configured to engage the pipe string, wherein, if the pipe string slips relative to the assembly of wedged slips, the safety device is configured to be displaced with the pipe string into contact with the assembly of wedged slips, and contact the assembly of wedged slips, when the assembly of wedge slips are engaged with the pipe string, so that a force from the assembly of wedged slips to the pipe string is increased in response to the contact of the safety device with the assembly of wedged slips, wherein the safety device comprises a support structure and a clamping arrangement comprising a first engagement member and a second engagement member, which clamping arrangement comprises a disengaged state in which the pipe string is freely movable in respect to the safety device and an engaged state in which the safety device is firmly engaged with the pipe string, wherein the support structure comprises a recess adapted to receive an envelope surface of the pipe string, and wherein the first engagement member and the second engagement member are arranged in different parts of the recess so that opposite sides of the pipe string are clamped between the first engagement member and the second engagement member when the clamping arrangement is in the engaged state; and a robot unit, wherein the safety device is a separate element configured to be gripped and operated by the robot unit, wherein the safety device comprises a clamping mechanism for moving at least one of the first engagement member and the second engagement member towards and away from each other, thereby changing the clamping arrangement between the engaged state and the disengaged state, wherein the clamping mechanism comprises an elongated sleeve element with an elongated opening comprising a primary threading, and a displacement rod comprising a secondary threading, wherein the displacement rod is arranged in the opening so that said primary threading and secondary threading engage with each other, and wherein the elongated sleeve element comprises further connection means adapted to enable connection to a tool for enabling the elongated sleeve element to be set into rotation in relation to a longitudinal axis of the elongated sleeve element.

2. The safety system according to claim 1, wherein the clamping mechanism is configured to act on at least the first engagement member with a force that displaces the first engagement member towards and away from the second engagement member.

3. The safety system according to claim 1, wherein engagement of the primary threading with the secondary threading creates a friction force that holds the elongated sleeve element and the displacement rod fixed when the clamping arrangement is in the engaged state.

4. The safety system according to claim 1, wherein the support structure further comprises a holding means for enabling the safety device to be held while allowing the elongated sleeve element to be set into rotation.

5. The safety system according to claim 1, wherein the elongated sleeve element comprises connection means adapted to enable connection to a robot arm for enabling the elongated sleeve element to be set into rotation in relation to a longitudinal axis of the elongated sleeve element.

6. The safety system according to claim 1, wherein the displacement rod comprises a portion with a non-circular cross-section fitting complementary and slidingly into an opening in the support structure.

7. A safety system for a pipe string, the safety system comprising: a safety device configured to attach to a pipe string, the safety device comprising a support structure and a clamping arrangement, the support structure comprising a recess adapted to receive the pipe string, and the clamping arrangement comprising a first engagement member and a second engagement member, wherein, when the pipe string is received in the recess, the first engagement member and the second engagement member are arranged in the recess to be on opposite sides of the pipe string, wherein the first engagement member is configured to extend toward or retract from the second engagement member, wherein the second engagement member is configured to remain stationary relative to the support structure, and wherein the clamping arrangement comprises a disengaged state in which the pipe string is freely movable in respect to the safety device and an engaged state in which the safety device is firmly engaged to the pipe string, wherein the safety device further comprises an elongated sleeve element that is rotationally attached to the support structure, wherein rotation in a first direction of the elongated sleeve element relative to the support structure extends the first engagement member toward the second engagement member, and wherein rotation in a second direction of the elongated sleeve element relative to the support structure retracts the first engagement member away from the second engagement member; and a robot unit, wherein the safety device is a separate element from the robot unit and the robot unit is configured to rotate the elongated sleeve element relative to the support structure to extend or retract the first engagement member toward or away from the support structure and hold the support structure stationary relative to the robot.

8. The safety system of claim 7, further comprising an assembly of wedged slips, wherein if the pipe string slips relative to the assembly of wedged slips the safety device is configured to be displaced with the pipe string into contact with the assembly of wedged slips when the assembly of wedged slips is engaged with the pipe string, thereby interacting with the assembly of wedged slips so that a force from the assembly of wedged slips to the pipe string is increased in response to the contact of the safety device with the assembly of wedged slips.

9. A method for conducting a subterranean operation, the method comprising: engaging a pipe string in an opening of a rig floor with an assembly of wedged slips; gripping a safety device via a robot, the safety device comprising a support structure with a recess, a clamping arrangement with a first engagement member and a second engagement member, and an elongated sleeve member rotationally attached to the support structure; holding, via the robot, the support structure stationary relative to the robot; rotating, via the robot, the elongated sleeve member in a first direction relative to the support structure, thereby extending the first engagement member toward the second engagement member, with the second engagement member being stationary relative to the support structure; and engaging the pipe string with the first engagement member and the second engagement member in response to extending the first engagement member toward the second engagement member with the first engagement member and the second engagement member disposed in the recess on opposite sides of the pipe string.

10. The method of claim 9, further comprising: displacing the safety device with the pipe string when the pipe string slips relative to the assembly of wedged slips; and increasing an engagement force of the assembly of wedged slips against the pipe string in response to the safety device interacting with the assembly of wedged slips when the safety device is displaced with the pipe string.

11. The method of claim 9, further comprising rotating, via the robot, the elongated sleeve member in a second direction relative to the support structure, thereby retracting the first engagement member away from the second engagement member, with the second engagement member being stationary relative to the support structure; and disengaging the pipe string from the first engagement member and the second engagement member in response to retracting the first engagement member away from the second engagement member.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) In the following is described examples of preferred embodiments illustrated in the accompanying drawings, wherein:

(2) FIG. 1 discloses a schematic view of safety system comprising a safety device according to an embodiment of the invention;

(3) FIG. 2 discloses a safety device according to an embodiment of the invention seen in two views;

(4) FIG. 3a discloses a first side view of the safety device in FIG. 2 seen along section A-A;

(5) FIG. 3b discloses the safety device in FIG. 2 in the first side view;

(6) FIG. 3c discloses the safety device in FIG. 2 in a second side view;

(7) FIG. 4 discloses an exploded view of the safety device in FIG. 2; and

(8) FIG. 5 discloses a safety device according to a further embodiment of the invention.

DETAIL DESCRIPTION OF THE INVENTION

(9) In FIG. 1 is a safety system 1 according to an embodiment of the invention disclosed. The system 1 is employed at a drilling arrangement 3 for a hydrocarbon well. The drilling arrangement 3 comprises an assembly table/rig floor 5 with an opening 7 through which a pipe string 10 is extending down to the hydrocarbon well. The pipe string 10 comprises a plurality of pipe sections 12. In FIG. 1, four connected pipe sections 12 of the pipe string 10 are seen and a further pipe section 12 is about to be connected to the pipe string 10.

(10) Each pipe section 12 comprises respective threading 13 at the end portions for connection to further pipe sections 12. During the drilling operation, the pipe string 10 is gradually extended by connecting further pipe sections 12 to the pipe string 10 above the assembly table 5 and gradually shifting the pipe string 10 down the opening 7 of the assembly table 5.

(11) The pipe string 10 often comprises a large number of pipe sections 12 connected together and constituting a significant weight. During connecting further pipe sections 12 to the pipe string 10, the pipe string 10 is held firmly at the assembly table 5 by means of assembly of wedged slips 14 that is suspended in the assembly table 5 at the opening 7. In FIG. 1, the assembly of wedged slips 14 is schematic illustrated as a single wedged shaped unit. It shall however be understood that the assembly of wedged slips 14 normally comprises a plurality of wedged parts arranged to a unit.

(12) The system 1 further comprises a safety device 20 attached to an envelope surface of a pipe section 12 of the pipe string 10 above the assembly table 5 and the assembly of wedged slips 14. In an event that the pipe string 10 would start slipping through the assembly of wedged slips 14 and down through opening 7 in the assembly table 5, the safety device 20 is displaced together with the pipe string 10 into contact with the assembly of wedged slips 14 and thereby acting on the assembly of wedged slips 14 so that the force subjected by the assembly of wedged slips 14 on the pipe string 10 is increased. Thereby, the force subjected by the assembly of wedged slips 14 on the pipe section 12 is increased until the pipe string 10 is stopped from slipping further down into the opening 7 of the assembly table 5.

(13) The safety device 20 will be explained in further details with reference to FIGS. 2-5.

(14) In FIG. 2 a safety device 20 according to an embodiment of the invention is disclosed. The safety device 20 is seen from two different orientations. In FIG. 4 is an exploded view of the safety device 20 in FIG. 2 is disclosed.

(15) The safety device 20 comprises a support structure 22 and a clamping arrangement 24. The support structure 22 comprises a recess 30 adapted to receive the envelope surface of the pipe section 12 of the pipe string 10.

(16) The clamping arrangement 24 comprises a first engagement member 32 and a second engagement member 34 at the recess 30. The clamping arrangement 24 comprises a disengaged state in which the pipe section 12 is freely movable in respect to the device 20 and an engaged state in which the device 20 is firmly connected to the pipe section 12 of the pipe string 10.

(17) The first engagement member 32 and the second engagement member 34 are arranged in different parts of the recess 30 so that opposite sides of the pipe section 12 are clamped between the first engagement member 32 and the second engagement member 34 when the clamping arrangement 24 is in the engaged state.

(18) With reference to FIGS. 3a-3c, the safety device 20 further comprises a clamping mechanism 40 for moving at least one of the first engagement member 32 and the second engagement member 34 towards and away from each other. In the disclosed embodiment, the clamping mechanism 40 is configured to displace the first engagement member 32 towards and away from the second engagement member 34, while the second engagement member 34 is arranged in a static position in relation to the support structure 22.

(19) The first engagement member 32 and a second engagement 34 member comprise a contact member 36 comprising respective dies for contacting the envelope surface of the pipe section 12. Thereby, it is assured that a firm contact between the envelope surface and the engagement members 32, 34 is provided.

(20) The clamping mechanism 40 is configured to act on at least the first engagement member 32 with a force that displaces the first engagement member 32 towards and away from the second engagement member 34. Furthermore, the first engagement member 32 is adapted to provide a clamping force to the envelope surface of the pipe section 12 when the clamping arrangement 24 is in the engaged state.

(21) The clamping mechanism 40 comprises an elongated sleeve element 42 and a displacement rod 44. The sleeve element 42 comprises an opening adapted to allow the displacement rod 44 to be inserted. The sleeve element 42 comprises a spring element 45 that is compressed during engagement to provide a secure clamping force. Accordingly, once the clamping arrangement 24 has been changed to the engaged state, the engaged stated is configured to be maintained by means of the spring element 45 until the clamping arrangement 24 is shifted to the disengaged stated.

(22) The sleeve element 42 comprises a primary threading 50a in the opening and the displacement rod 44 comprises a secondary threading 50b. The sleeve element 42 and the displacement rod 44 are positioned so that the primary threading 50a and the secondary threading 50b are engaging with each other. Accordingly, the primary threading 50a relates to an inner threading and the secondary threading 50b relates to an outer threading. Thereby, the sleeve element 42 and the displacement rod 44 have the function of a linear actuator.

(23) The sleeve element 42 is adapted to be set into rotation. By means of the selected rotation direction of the sleeve element 42, the displacement rod 44 is displaced towards or away from the first engagement member 32.

(24) The primary threading 50a and secondary threading 50b are arranged to engage with a friction force that holds the elongated sleeve element 42 and the displacement rod 44 fixed when the clamping arrangement 24 is in the disengaged state and the engaged state.

(25) The opening of the sleeve element 42 is adapted to be provided with a lubricant. The clamping mechanism 40 further comprises a bearing element 51 at an intersection between the sleeve element 42 and the support structure 22. In the disclosed embodiment of the invention, two intersections are present between the sleeve element 42 and the support structure 22, and are provided with respective bearing elements 51.

(26) The sleeve element 42 comprises connection means 52 adapted to enable connection to a robot arm/gripper 70 (refer to FIG. 2) for enabling the sleeve element 42 to be set into rotation around its longitudinal axis. In the disclosed embodiment, the connection means 52 comprises a cylindrical envelope surface that is adapted to be engaged by friction with a rotational roll of a tool, such as a rotational roll of a robot unit 70. WO2016/089216 discloses an example of such robot 70 with means for gripping and rotation. By means of the safety device 20 of the invention, a robot unit 70 can be used both for compiling the pipe string 10 and operating the safety device 20. Accordingly, by means of the invention, the process of the drilling operation comprising compiling the pipe string 10 and gradually shifting the pipe string 10 down the opening 7 of the assembly table 5 can be fully automated.

(27) The support structure 22 further comprises a holding means 55 for enabling the device 20 to be held and moved to different locations. In the disclosed embodiment, the holding means 55 is form of a bar member extending along the sleeve element 42 with a separating gap. The holding means 55 is adapted to enable the device 20 to be held while allowing the sleeve element 42 to be set into rotation. The holding means 55 are adapted to prevent rotation of the device 20 as such while the device being held and the sleeve element 42 is set into rotation.

(28) The sleeve element 42 comprises further connection means 60 adapted to enable connection to a tool for enabling the sleeve element 42 to be set into rotation in relation to its longitudinal axis. The further connection means 60 is in form of an external nut connected to the sleeve element 42. The further connection means 60 is for example a hexagonal nut. The connection means 60 provided an optional way of setting the sleeve element 42 into rotation in relation to its longitudinal axis, such as by a separate tool than a gripper arranged at a robot unit. Accordingly, further connection means 60 enables manual operation of the device 20.

(29) The displacement rod 44 of the clamping mechanism 40 further comprises a portion 70 with a non-circular cross-section. The non-circular portion 70, here shown as rectangular, is slidingly arranged in a corresponding opening in the support structure 22, thereby preventing rotation of the displacement rod and thereby also the first engagement member 32.

(30) In FIG. 5 is a safety device 20 according to a further embodiment of the invention disclosed. The safety device 20 differs from the embodiment in FIGS. 2-4 in that the first engagement member 32 is rotationally arranged in respect to the support structure 22. The clamping mechanism 40 is configured to induce a rotation of the first engagement member 32 so that the first engagement member 32 is rotated towards and away from the second engagement member 34. Thereby, the clamping arrangement 24 is changed between the engaged state and the disengaged state.

(31) The first engagement member 32 comprises an arm 80 and the clamping arrangement 24 comprises a pivot 82 between the arm 80 and the support structure 22. The clamping mechanism 40 is configured to act on the arm 80 with a force that rotates the arm 80 towards and away from the second engagement member 34. In the disclosed embodiment, the clamping mechanism 40 is arranged extending in a different direction that that the extension of the clamping mechanism 40 in the embodiment in FIGS. 2-4.

(32) It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb “comprise” and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The article “a” or “an” preceding an element does not exclude the presence of a plurality of such elements. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.