DEVICE AND METHOD FOR SUSPENSING LOADS FROM A BRACKET OF AN ELEVATOR OF A DRILLING SYSTEM AND CORRESPONDING DRILLING SYSTEM ASSEMBLY

Abstract

Device for suspending loads (16) on a bracket (6, 8) of an elevator (4) of a drilling rig (1), comprising: - an upper bracket clamp (36) for re-clamping the bracket (6, 8); - a lower bracket clamp (38) for re-clamping the bracket (6, 8);and a connecting part (40) which is connected to the upper clamp (36) by means of an upper connecting device and to the lower clamp (38) by means of a lower connecting device, wherein the connecting part (40) is further provided with a coupling device to connect the connecting part (40) to the load (16) which is to be suspended from the clamp (6, 8), wherein at least one of the connecting devices is designed to allow translation of the connecting part (40) with respect to one of the clamps (36, 38), while another of the connecting devices is designed to prevent translation of the connecting part (40) with respect to the other clamps (38, 36).

Description

The invention relates to a device for suspending loads from a bracket of an elevator in a drilling rig. For example, a compensator can be suspended from the bracket using the device. In the oil and gas industry, pipes are used to extract oil or gas. These pipes consist of several sections joined together at their ends, for example, via a threaded connection, to form a continuous pipe. To create a pipe that extends into a well, the pipe sections can be inserted sequentially, with each new section being connected to the uppermost section protruding from the well, after which the pipe is advanced further into the well. The positioning of this new pipe section is controlled by a drilling rig. To position the pipe sections, the drilling rig is equipped with an elevator that can grip the pipe section and raise and lower it. These elevators are suspended using elevator yokes, commonly referred to simply as "yokes" or "elevator bars." Elevator yokes are typically metal bars with a loop or eyelet at each of their outer ends. The loop at the top of the yoke is attached to the drilling rig, for example, to a power swivel or clamp, and the loop at the bottom of the yoke is attached to the main elevator. Generally, the aim is to avoid moving individual shots through the main elevator, as the tool is not designed or configured to handle the relatively small weight of an individual shot gently and to follow the small movements when that section of pipe is added to or removed from the string. For this reason, a system for handling individual shots may include a compensator and an individual shot elevator. However, such a compensator should be suspended from a power swivel or other device for moving the individual shot elevator. Generally, drilling rigs offer only a limited number of suitable structures for suspending loads. Particularly few options are available for suspending loads that need to move with the lifting device, the power swivel, and / or the elevator. In practice, it is common to suspend a compensator from an upper eyelet of an elevator yoke using steel wires. However, this type of suspension is unreliable and unsafe. The steel wires can fail, leading to damage to the pipes and / or the system, and in the worst case, injury to people working there. Nevertheless, this type of suspension is still used in practice because safer solutions are lacking. Regarding the specific prior art, reference is made to US 2015 / 0337608A1. This relates to a device for suspending loads from a bracket of an elevator of a drilling rig, wherein the device comprises an upper bracket clamp for re-clamping the bracket, a lower bracket clamp for re-clamping the bracket, and a connecting part that is connected to the upper bracket clamp by means of an upper connecting device and to the lower bracket clamp by means of a lower connecting device, wherein the connecting part is further provided with a coupling device to connect the connecting part to the load that is to be suspended from the bracket 100. One objective of the invention is therefore to create a device to overcome or at least reduce the aforementioned disadvantages, more precisely a device for safely suspending loads, for example a compensator, from a bracket of an elevator of a drilling rig. This objective is achieved by the device for suspending loads from a bracket of an elevator of a drilling rig according to embodiments of the invention. In one embodiment, the device comprises an upper clamp for securing the yoke and a lower clamp for securing the yoke. The device further comprises a connecting element that is connected to the upper clamp by means of an upper connecting element and to the lower clamp by means of a lower connecting element. The connecting element is also provided with a coupling device for connecting it to the load to be suspended from the yoke. Preferably, the upper connecting element is designed to allow translation of the connecting element relative to the upper clamp, while the lower connecting element is preferably designed to prevent translation of the connecting element relative to the lower clamp. By clamping the device to the bracket, an additional suspension point is created for hanging a load. The upper connecting device is designed to allow translation of the connecting part relative to the upper clamp, which is generally a downward movement. Preferably, the upper connecting device is designed such that the connecting part moves downward relative to the upper clamp when the load suspended from the device exceeds a predetermined load. Therefore, an overload, i.e., a load exceeding a predetermined limit, causes the connecting part to shift relative to the upper clamp, while the connecting part remains unchanged relative to the lower clamp. Consequently, an overload can be detected by a worker, and appropriate countermeasures can be taken. In one embodiment, the upper connecting device comprises an elongated hole and a part to be received for insertion into the elongated hole, wherein the part to be received is movable in the elongated hole. In other words, in this specific embodiment, the translation of the connecting part with respect to the upper clamp is made possible by providing an elongated hole in which a corresponding part to be received can perform a translation. In a first example, the elongated hole is provided in the connecting piece. The part to be received is, for example, a bolt that passes through the elongated hole of the connecting piece. In a second example, the elongated hole is provided in the upper clamp. The part to be clamped is, for example, a bolt that passes through the elongated hole of the upper clamp. In one embodiment, the lower connecting device comprises an opening provided in the connecting part or in the lower clamp, and a further part to be received for insertion into the opening. Preferably, the opening and the further part to be received are dimensioned such that the part to be received fits tightly in the opening, thereby essentially preventing any translation of the connecting part with respect to the lower clamp. In one embodiment, the connecting part has a plate shape. In another embodiment, the plate-shaped connecting part has a substantially triangular shape. In an embodiment in which the upper connecting device comprises an elongated hole and a receiving part, the lower connecting device comprises an opening and a further receiving part, and the connecting part is triangular and plate-shaped, the elongated hole or the receiving part of the upper connecting device is provided near a first corner of the triangular connecting part, while the opening or the further receiving part of the lower connecting device is provided near a second corner of the triangular connecting part, and the coupling device for connecting the connecting part to the compensator is provided near a third corner of the triangular connecting part. In one embodiment, the device further includes a display designed to indicate the position of the connecting part in relation to the upper clamp. In another embodiment, the display is designed to indicate a first position of the connecting part in relation to the upper clamp as a safe position and a second position, to which the connecting part has moved in relation to the first position, as an unsafe position. In one embodiment, an inner surface of the upper clamp and / or the lower clamp, wherein this inner surface faces the clamp, has at least one rounded burr which is intended to come into contact with the clamp. In another embodiment, the inner surface comprises two rounded ridges. In another embodiment, a groove is provided between the rounded ridges of the inner surface. In one embodiment, at least one of the upper clamp and the lower clamp has a clamping section comprising two connectable parts, which preferably have a substantially V-shaped or substantially C-shaped cross-section. The invention further relates to a drilling rig assembly comprising: at least one elevator suspended on brackets, a compensator connected to the elevator, and the device described above, which is connected to the compensator and at least one of the brackets. The invention further relates to a method for suspending a load from a bracket of an elevator of a drilling rig using the device described above, wherein the method comprises: - clamping the bracket with the upper bracket clamp; - clamping the bracket with the lower bracket clamp at a position below the upper bracket clamp; and - connecting the load to the coupling device of the connecting part. More precisely, the procedure can include connecting a compensator to the elevator's bracket by connecting the compensator to the coupling device of the connecting part. The advantages and effects described above with regard to the embodiments of the device also apply accordingly to the drilling rig assembly and the method according to embodiments of the invention. Further advantages, features, and details of the invention will become clear based on its preferred embodiments, for which reference is made to the accompanying figures: - Fig. 1 shows a drilling rig assembly comprising a power rotary head, a main elevator, and a single-shot elevator, wherein the main elevator is suspended from two brackets and a device of a first embodiment of the invention is clamped to each of the brackets; - Fig. 2 shows a clamp for use as an upper bracket clamp and / or lower bracket clamp in a device according to embodiments of the invention; - Fig. 3A shows a device according to an embodiment of the invention in a safe operating state, with the forces that can be applied being indicated; and - Fig. 3B shows the device of Fig. 3A in an unsafe operating state. A drilling rig 1 can include a power rotary head 2 from which a main elevator 4 is suspended via elevator brackets 6, 8, also referred to as elevator rods or linkages (Fig. 1). The main elevator 4 is provided with lugs 10, 12. Each lug 10, 12 is connected to an eyelet at the lower end of a corresponding bracket 6, 8. A compensator 16 is suspended from the bracket 8 by means of the device 18 of one embodiment of the invention. The other bracket 6 is provided with a device 18' of the same type. Lines 20, 22 connect the clamping devices 18, 18' to a drive pulley 24. The lines 20, 22 are further connected to the lugs 10, 12 of the main elevator 4 by means of hooks 11, e.g., carabiners. A single-shot elevator 26 is suspended from the drive pulley 24. The example in Fig. 1 further shows the upper part of a shot 28, i.e., a pipe section 28, for positioning using the single-shot elevator 26. An elastic cord 29 is connected to the cord 20 and to the bracket 8 to pull the drive pulley 24 and the single-shot elevator 26 away from the borehole center when no shot 28 is suspended. The drilling rig 1 or the drilling rig assembly 1 of the example of Fig. 1 further comprises a filling tool 14. In the illustrated embodiment, the main elevator 4 is of the slip or catcher type. However, other suitable types of elevators can also be used. The brackets 6, 8 in the exemplary embodiment have a minimum length of approximately 460 cm. However, according to the invention, shorter lengths are also possible, for example. In the example shown in Fig. 1, the compensator 16 comprises a compensator cylinder 30 connected to a hydraulic or pneumatic line 32 suspended from a bundle support 34. However, other types of compensators can also be used, for example, a compensator comprising a spring. The upper end of the bracket 8 is provided with an eyelet. The device 18 comprises an upper clamp and a lower clamp, which are provided on the bracket. A connecting plate is connected to both clamps and has a coupling device for connecting to a load, for example to a compensator 16 of the exemplary embodiment. The device 18 is in a safe state, with the load on the device 18 being within acceptable limits. The connecting plate is marked to indicate that the device 18 is in a safe state. In this example, the mark is a green dot. However, the invention is not limited to such a mark. For example, a text marking could be used to indicate the safe state; e.g., the connecting plate could be marked with the letters "SAFE" instead of the green dot. The device is in an unsafe condition, with an excessively heavy load suspended from it. Due to the overload, the lower clamp is displaced downwards relative to the upper clamp. This is illustrated by comparing distances D1 and D2. This causes the connecting plate to move downwards relative to the upper clamp. Because of this translation of the connecting plate, which in this example is a downward movement, the green dot is hidden, while a second marker becomes visible. In this example, the second marker is a red dot, but alternatively, another marker could be used to indicate the unsafe condition, such as a text marker, e.g., "UNSAFE". Each clamp consists of two interconnected parts. To allow movement of the connecting plate relative to the upper clamp, one embodiment of the connecting plate includes a slot to receive a coupling element for connecting the upper clamp. The coupling element for connecting the upper clamp is, for example, a bolt that is inserted into the slot. The connecting plate further includes an opening for receiving another component, for example, a bolt, to connect the lower clamp to the connecting plate. The opening and the other component fit closely together, preventing translation of the connecting plate relative to the lower clamp. However, some rotation of the connecting plate relative to the lower clamp may be permitted. The connecting plate is also provided with an opening for connecting the load to the connecting plate. In this example, the opening has a circular shape.However, the opening can also have a different shape, for example, a hexagon. The opening has a hexagonal shape, but can also have a different shape, for example, a circle. Each of the clamps comprises two parts 36a, 36b and 38a, 38b, respectively. The two parts 36a, 36b and 38a, 38b of the clamp are joined together by a bolt-and-nut connection 53 (Fig. 3A). For this purpose, the parts 36a, 36b, 38a, 38b of the clamps each have a through opening 54, 56 for receiving the bolt (Fig. 2). The parts 36a, 36b, 38a, 38b of the clamps each have a clamping section 58 with a substantially V-shaped cross-section. Alternatively, the clamping section 58 can have a substantially C-shaped cross-section. The clamping sections 58 of the two corresponding parts 36a, 36b and 38a, 38b of the clamp are joined together around the bracket 8, and the bolt and nut connection 53 is inserted and tightened to clamp the clamp to the bracket 8. A first clamping section 38b of each clamp is provided with two spaced-apart flanges 60, 62 (Fig. 2). The flanges 60, 62 are provided with openings for receiving a coupling element, for example, bolts 64, 66, in order to attach the connecting plate 40 to both clamps (Fig. 3A). In the embodiment shown in the figures, the other clamping section 36a, 36b of the clamps does not include flanges, but it can optionally also be provided with such flanges. The inner surface of the clamps, i.e., the surface facing the bracket 8 when the clamp is fitted onto the bracket 8, is provided with at least one ridge or rib 68, which is rounded and intended to contact the bracket 8. In the embodiment shown in the figures, the inner surface is provided with two opposing, paired rounded ridges 68. Optionally, a groove 70 can be provided between each pair of rounded ridges 68. As can be seen in Figures 3A and 3B, the safety indicator 42 is provided on one or both surfaces of the connecting plate 40 above the slot 48, while the unsafe indicator 44 is provided on one or both surfaces of the connecting plate 40 below the slot 48. In the safe state (Figure 3A), the safety indicator 42 is located above the slot 48 and above the flange 62 and is therefore visible. If the connecting plate 40 moves downwards relative to the upper terminal 36 due to overload, i.e., in an unsafe state (Figure 3B), the safety indicator 42 also moves downwards and ends up behind the flange 62 of the terminal 36. In the unsafe state, the safety indicator 42 is therefore no longer visible.In contrast, the uncertainty indicator 44 becomes visible when the connecting plate moves upwards with respect to the upper terminal 36, while the uncertainty indicator 44 disappears behind the flange 62 in the safe state (Fig. 3A). Fig. 3A further shows the forces exerted on the device 18. The load applied to the device 18, e.g., the load of a compensator suspended from the device 18, is denoted as F1. The moment in the connecting plate 40 generates a force F2, the direction of which is perpendicular to the direction of force F1. A force F3 results from force F2, while a force F4 results from force F1, which is opposed by friction between the lower clamp 38 and the bracket 8. Force F3 is added to the friction between the lower clamp 38 and the bracket 8 without being added to the downward force. When the load 16 is suspended from the brackets 6, 8, the upper bracket clamp 36 is clamped around the bracket 6, 8, and the lower bracket clamp 38 is clamped around the bracket 6, 8 at a position that, in use, lies below the upper bracket clamp 36. The load 16 is connected to a coupling device. This enables the load, for example a compensator 16, to be securely suspended from the bracket 6, 8 of the drilling rig 1. The invention is by no means limited to the embodiments described above. The rights sought are defined by the following claims, within the scope of which modifications may be considered. For example, features of a first embodiment may be applied in another embodiment to realize a new embodiment of the invention.

Claims

Device for suspending loads (16) on a bracket (6, 8) of an elevator (4) of a drilling rig (1), comprising: - an upper bracket clamp (36) for re-clamping the bracket (6, 8); - a lower bracket clamp (38) for re-clamping the bracket (6, 8);and a connecting part (40) which is connected to the upper clamp (36) by means of an upper connecting device and to the lower clamp (38) by means of a lower connecting device, wherein the connecting part (40) is further provided with a coupling device to connect the connecting part (40) to the load (16) which is to be suspended from the clamp (6, 8), wherein at least one of the connecting devices is designed to allow translation of the connecting part (40) with respect to one of the clamps (36, 38), while another of the connecting devices is designed to prevent translation of the connecting part (40) with respect to the other clamps (38, 36). Device according to claim 1, wherein the upper connecting device allows translation and comprises an elongated hole and a part to be received for insertion into the elongated hole, wherein the part to be received is movable in the elongated hole. Device according to claim 2, wherein the elongated hole is provided in the connecting part (40). Device according to claim 2, wherein the elongated hole is provided in the upper clamp (36). Device according to one of the preceding claims, wherein the lower connecting device comprises an opening provided in the connecting part or in the lower clamp (38) and a further part to be received for insertion into the opening. Device according to one of the preceding claims, wherein the connecting part (40) has a plate shape. Device according to claim 6, wherein the plate-shaped connecting part (40) has a substantially triangular shape. Device according to one of claims 2-4 and claim 5 and claim 7, wherein the elongated hole or the part to be received of the upper connecting device is provided near a first corner of the triangular connecting part (40), while the opening or the further part to be received of the lower connecting device is provided near a second corner of the triangular connecting part (40), and the coupling device for connecting the connecting part to the compensator (16) is provided near a third corner of the triangular connecting part (40). Device according to one of the preceding claims, further comprising a display designed to indicate the position of the connecting part (40) in relation to the clamp, preferably the upper clamp (36). Device according to claim 9, wherein the indicator (44) is designed to indicate a first position of the connecting part (40) in relation to the clamp, preferably the upper clamp (36), as a safe position and to indicate a second position, to which the connecting part has moved in relation to the first position, as an unsafe position. Device according to one of the preceding claims, wherein an inner surface of the upper clamp (36) and / or the lower clamp (38), wherein this inner surface faces the clamp (6, 8), has at least one rounded burr which is intended to come into contact with the clamp (6, 8). Device according to claim 11, wherein the inner surface has two rounded ridges (68). Device according to claim 12, wherein a groove (70) is provided between the rounded ridges (68) of the inner surface. Device according to one of the preceding claims, wherein at least one of the upper clamp (36) and the lower clamp (38) has a clamping section (58) comprising two connectable parts (36a, 36b, 38a, 38b) which preferably have a substantially V-shaped cross-section. Drilling rig assembly comprising: at least one elevator (4) suspended from brackets (6, 8), a compensator connected to the elevator (4), and a device according to one of the preceding claims connected to the compensator (16) and at least one of the brackets (6, 8). Method for suspending a load (16) from a bracket (6, 8) of an elevator (4) of a drilling rig (1) using the device according to any one of claims 1-14, the method comprising: - clamping the bracket (6, 8) with the upper bracket clamp (36); - clamping the bracket (6, 8) with the lower bracket clamp (38) at a position below the upper bracket clamp (36); and - connecting the load (16) to the coupling device of the connecting part (40).

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