EP3874115B1 - Lifting plug - Google Patents

Description

The present invention relates to a lifting plug intended to be engaged with an elevator of an oil platform to facilitate the handling and assembly of tubular elements together in order to form a tubular string for drilling and or exploitation of a hydrocarbon well. The elevator is one of the essential pieces of equipment on an oil rig, notably described in the API 8B and 8C standards.

By tubular element intended for the drilling and/or exploitation of hydrocarbon wells, is meant any element of substantially tubular shape capable of being assembled to another element of substantially tubular shape, in particular by screwing, in order to constitute a train of rods intended either to drill a hydrocarbon well, or to form an underwater riser for the maintenance or operation of such wells, or to casing the well, or a production string (also called tubing in English ) involved in the operation of the well. The lifting plug according to the invention can also be used for lowering heavy loads into a well.

When assembling a drill string, it is necessary to add the tubular elements progressively above the well. There are therefore the tubes already assembled forming the start of the drill string which are retained in the well so that the last tube added emerges from the well. And near the well, there is a stock of tubular elements that will be added to the drill string to form the tubular column. The object of the present invention is to facilitate the addition of additional tubular elements to the drill string.

In particular, the invention relates to the lifting plug operated by an elevator on a drilling platform and/or to the exploitation of hydrocarbon wells. In practice, to form the tubular column, the lifting plug is mounted on a tubular element of a stock of tubes placed horizontally. The tubes are assembled 3 by 3 to form sections of three tubes, which are then stored vertically. The lifting plug allows for easy handling of individual tubes to form sections of three tubes. For the displacement of the tubular elements, the lifting plug is caught in a jaw of an elevator, and this elevator then operates the displacement of the assembly formed by the lifting plug fixed to the tubular element. The elevator makes it possible to bring this new tubular element, just like a section of three tubes, above a string of rods already in the well. The new tubular element is screwed via a screwing table to the drill string. After this screwing, the elevator allows the entire drill string to be lowered into the well, so that the drill string is lowered to platform height, to allow the lifting plug to be detached.

When using the lifting plug, the latter must support tensile loads equivalent to the weight of a tube, a section of three tubes, and also to the weight of an entire drill string.

Each diameter of tubular element corresponds to a particular lifting glue. In fact, in order to be able to be mounted on a tubular element, the lifting plug must have a thread complementary to that of this tubular element. De facto, the larger the diameter of the tubular elements to be assembled, the larger the diameter of the lifting plug itself. Moreover, as this lifting plug must be engaged in the jaw of an elevator and withstand forces in tension or compression at the level of the jaw, and also in tension linked to the weight of the tubular element to be moved, this lifting plug is preferably made of steel and has mechanical properties allowing the required use. The lifting plug is, for example, made of low-alloy steel in accordance with European standard EN10027.

Compliance with operator safety standards on an oil rig recommends that the loads that must be handled by operators do not exceed a certain weight. However, the weight of the lifting plugs exceeds the required limits for certain diameter sizes. It is then necessary to equip the platform with tools specifically dedicated to handling the lifting plug, or more simply to reuse the lift available on the platform. But when the operator wants to use the elevator, the lifting plugs of the state of the art require a high number of manipulations of the jaw of the elevator relative to the lifting plug.

For example, at the end of the screwing of a new tubular element on a drill string, the jaw must release the lifting plug to allow its detachment from the tubular element. When the lifting plug is detached from the tubular element, it is necessary to use other handling equipment, such as a pallet truck, to move it again. Brought to the level of a new tubular element, the lifting plug is screwed into it, and only then the jaw of the lifter will be put in place around the lifting plug.

Although this method respects safety standards on oil rigs, it is long and expensive in terms of labor time to comply with, and in terms of the number of manipulations. Each manipulation involving a risk, the occurrence of an incident becomes statistically higher. There is therefore a need to reduce the manipulation time, and in particular to reduce the number of manipulations. There is also a need to reduce the time and cost of assembling drill strings.

We know from the document US 2017088401 A1 an underlift handling assembly for gripping, handling and maneuvering a underlift or other tubular member. A clevis member defining a slot is rotatably attached to a lifting frame which, in turn, can be suspended from a hoist, winch or other lifting device. A door can be selectively opened to a sub-lifter or other tubular member to be received in the slot and then closed to secure the sub-lifter or other tubular member in place. A motor can selectively rotate the clevis member relative to the lift frame, thereby altering the orientation of a sub-lifter or other tubular member held in the slot.

We know from the document WO 2011090390 A1 a lifting object for lifting and handling collarless components that penetrate a bottom assembly ("BHA").
We know from the document US 2013255956 A1 a sealing subsystem for connecting fluid lines, comprising first and second fluid lines, each comprising a terminal end with an inside diameter. A seal includes an internal channel and first and second pin ends, wherein a pin end can be removably inserted into the terminal end of the fluid line, the other end of the pin extending from the terminal end of the fluid line. A seal forms a seal between the sub-seal and the inside diameter of the first fluid line terminal end. The extension pin end is configured to be inserted into the terminal end of the second fluid line to establish a sealed fluid connection between the first and second fluid lines.

We know from the document US 5050673A an elevator cement plug container for use with an inclined drilling rig.

We know from the document US 4479537A a hydraulically operated assembly that can be removably attached to the wellhead of an oil well to simultaneously elevate a tubing rack that has a tubing string supported in a centered or offset position relative thereto at an elevation where replacements or repairs can be made to electrical components including the lower electrical connector.

The invention proposes a solution to the problem posed by proposing a lifting plug which can be assembled and disassembled from the tubular elements to be moved while remaining engaged in the jaw of the elevator. To this end, the subject of the invention is a lifting plug for lifting a tubular string in a gas and/or oil production well, the plug comprising a body and a thread at one axial end of this body to cooperate by screwing with a threaded portion of a tubular element of the tubular column, the body comprising a cylindrical surface capable of being placed in a jaw of an elevator of an oil platform, the body comprising two external collars, an upper collar and an intermediate flange, such that the cylindrical surface of the body is arranged between the two external flanges, the upper flange forming a shoulder on which the jaw of the elevator can come to rest, characterized in that the intermediate flange comprises a handling bore of the plug allowing the insertion across the body of a bar emerging at two separate points of the intermediate collar.

Advantageously, the handling bore may comprise a first orifice emerging radially outwards relative to a longitudinal axis from the body. Better still, the handling bore may comprise a second orifice opening out radially outwards relative to a longitudinal axis of the body, this second orifice being diametrically opposed to the first orifice.

In particular, the upper flange can be arranged at a second end of the body of the stopper, opposite an end of this body adjacent to the thread, relative to a longitudinal axis of the body.

More precisely, the intermediate flange can be arranged between the cylindrical surface and the thread.

Preferably, the outer diameter of the cylindrical surface may be equal to the outer diameter of the tubular element on which the lifting plug is screwed, in particular equal to the nominal outer diameter of this tubular element. The nominal outer diameter is considered according to usage, at a distance from the threaded ends of this tubular element, called “nominal pipe body outer diameter” in English.

Advantageously, the body may be hollow and emerging at its two longitudinal ends. This arrangement reduces the handling weight of the lifting plug and facilitates the circulation of sludge if necessary.

To limit the number of manipulations of a jaw of an elevator around the lifting cap, a distance between a shoulder of the upper collar and an annular surface of the intermediate collar opposite this shoulder may be greater than an axial length of the thread, in particular at least 1.5 times greater than this axial length of the thread.

Preferably, the lifting plug can be made in one piece, in particular obtained by machining a billet.

According to a preferred embodiment, the thread may be formed on the outer periphery of an outer surface of the body.

• La figure 1 illustre de manière schématique les équipements d'une plateforme pétrolière, notamment lors de l'assemblage d'éléments tubulaires à une colonne tubulaire équipant un puits en exploration ou production;
• La figure 2 illustre en perspective un mode de réalisation d'un bouchon de levage selon l'invention;
• La figure 3 est une vue en coupe longitudinale du bouchon de levage selon la Figure 2;
• La figure 4 est une vue en coupe longitudinale du bouchon de levage selon la Figure 2 retenu à un élément tubulaire et en prise dans un élévateur.

The present invention will be better understood on reading the detailed description of a few embodiments taken by way of non-limiting examples and illustrated by the appended drawings, in which:

• The figure 1 schematically illustrates the equipment of an oil platform, in particular during the assembly of tubular elements to a tubular string equipping a well in exploration or production;
• The figure 2 illustrates in perspective an embodiment of a lifting plug according to the invention;
• The picture 3 is a longitudinal sectional view of the lifting plug according to the Figure 2 ;
• The figure 4 is a longitudinal sectional view of the lifting plug according to the Figure 2 retained to a tubular member and engaged in an elevator.

The Figure 1 diagrams an oil platform during the installation of a string 1, also called drill string 1, in a well 2. A start of the drill string is retained in the well 2 by retaining means, such as a table blockage 3. The well 2, including during the deep insertion of the drill string, is fed by a flow of descending sludge 4 inside the drill string and rising 5 between the drill string and the walls of the well.

Near the well, there is a stock 6 of tubular elements 8 which it will be necessary to successively add to the drill string 1 to form the column useful for drilling and/or operating the well 2. The oil platform is equipped with means allowing the progressive addition of the tubular elements of the stock 6 to the column 1. The platform comprises in particular a screwing key 7 allowing to drive in rotation a tubular element so as to obtain its screwing on the drill string 1 retained by the blocking table 3.

In particular, the invention relates to a lifting plug 10 operated by an elevator 11 of the platform. In practice, to form the tubular column 1, the lifting plug is mounted on a tubular element 8 of the stock 6, and once engaged on this tubular element 8, the elevator 11 comes to cooperate with this lifting plug 10 for the displacement of the tubular element to the right of column 1 in formation. The tubular element 8 can also be called rod 8, or tube 8.

According to one embodiment of the invention, the lifting plug 10 comprises a hollow tubular body 12 with a longitudinal axis X. The body 12 is preferably made of steel.

In the example shown in figures 2 and 3 , the tubular body 12 is provided on part of its outer periphery with a thread 13. In this case, the lifting plug is intended to cooperate by screwing with a tubular element 8 which would be provided with a threaded end on its periphery interior. The tubular element 8 is for example a rod having a male thread at one end facing the ground, and provided at its other end with a female thread. This is then referred to as a column with integral joints. Alternatively, the tubular element may be an assembly consisting of a rod having a male thread at one end facing the ground and provided at its other end with another male thread, itself already screwed into a sleeve provided respectively with female threads at both ends of its inner rim. This is then referred to as a column with T&C type joints formed by the combination of a rod and a sleeve.

In an example not shown, the body 12 can alternatively be provided with a thread on its inner periphery, to cooperate with a male threaded end of a tubular element.

The body 12 has an axis of revolution X. In the example shown, where the tubular body 12 has an external thread 13, the body 12 comprises a frustoconical portion 26 from which the thread 13 protrudes. In a variant not shown, the surface 26 is not tapered but cylindrical, the thread 13 then emerging from this cylindrical surface. Surface 26 is defined by an envelope surface passing through the thread roots of thread 13. Thread 13 is machined. The body 12 comprises, in line with the thread 13, an internal cylindrical surface 40 of constant internal diameter along the axis X, in order to guarantee the critical sections of the connection formed between the cap and a rod to which it is screwed. Indeed, the lifting plug can be useful for lifting a column 1 consisting of several tens, or even hundreds, of rods, the connection thus formed between the lifting plug and the tube 8 must make it possible to hold these loads.

The internal diameter of the internal surface 40 is equal to the internal diameter observed in line with the threaded portion of the tube 8. In practice, if the tube 8 has an internal connection diameter Y, with manufacturing tolerances of plus α1 and/or minus β1, then the internal diameter of the cylindrical surface 40 will be machined according to the same tolerances as those of the tube, namely with a inside diameter between Y - β1 and Y + α1. Preferably, the internal diameter of the cylindrical surface 40 will be less than or equal to Y, such that the internal diameter of the cylindrical surface 40 will for example be between Y-β1 and Y.

The body 12 comprises an upper collar 14 and an intermediate collar 15 extending respectively radially outwards on either side of a tubular portion 16. The upper collar 14 defines an edge 17 orthogonal to the axis X defining a first axial end of the body 12. According to the embodiment represented the edge 17 defines an axial end of the body 12. The thread 13 is machined up to a second axial end 27, opposite relative to the axis X, to the edge 17 The body 12 has an axial length between its two axial ends 17 and 27 of the order of 800 mm, for example between 500 and 1200 mm.

The upper collar 14 and the intermediate collar 15 are external collars. The tubular portion 16 has the same internal diameter, along the axis X, from the upper flange 14 to the intermediate flange 15. The external diameter of the tubular portion 16 is a function of the nominal external diameter of the tube 8. In practice if the tube has a nominal outside diameter X, with manufacturing tolerances of plus α2 or minus β2, then the outside diameter of the tubular portion 16 will have the same manufacturing tolerances as that of the tube 8, namely with an outside diameter between X - β2 and X + α2. Preferably, the outside diameter of the tubular portion 16 may be greater than or equal to X, in particular between X and X+α2.

The tubular portion 16 defines an outer cylindrical surface 18, such that the wall thickness of this tubular portion 16 is constant between the two flanges 14 and 15. The inside diameter of the tubular portion is for example constant and equal to the inside diameter observed to the right of flanges 14 and 15.

The upper collar 14 has, for example, an outer diameter representing at least 105% of the outer diameter of the tubular portion 16. The upper collar 14 has a length along the axis X of the order of 80 mm to 120 mm.

The upper flange 14 has a surface perpendicular to the axis X, formed by the edge 17, and a shoulder 19 between a cylindrical periphery 20 of the upper flange 14 and the external cylindrical surface 18 of the tubular portion 16. The cylindrical periphery 20 extends between edge 17 and shoulder 19.

A jaw 30 is retained by a pivot 32 in slings 31, together they form part of the elevator 11. This jaw 30 is intended to come into engagement around the tubular portion 16. Alternatively, and as shown in figure 4 , this jaw 30 does not come into contact with the outer cylindrical surface 18, but in contact with the shoulder 19. The body 12 is then manipulated by the elevator, in suspension by pressing on the jaw 30. The upper collar 14 is then configured to support the tensile weight of a tubular element to which it would be fixed in order to move it.

The intermediate collar 15 has for example an outer diameter representing at least 105% of the outer diameter of the tubular portion 16. The intermediate collar 15 has a length along the axis X of the order of 50.8 mm to 76.2 mm.

The intermediate collar 15 has an outside diameter equivalent to that of the upper collar 14. The intermediate collar 15 has an axial length along the axis X that is less than that of the upper collar 14.

The intermediate collar 15 comprises two annular surfaces 21 and 22 respectively perpendicular to the axis X connected by an intermediate cylindrical periphery 23 of the intermediate collar 15. The annular surface 21 faces the shoulder 19. The intermediate cylindrical periphery 23 defines the length of the intermediate flange 15 along the X axis.

The intermediate collar 15 comprises a handling bore 24 having a first orifice 24a emerging radially outwards at the level of the intermediate cylindrical periphery 23. The handling bore 24 passes through and also emerges radially inwards through another orifice 24b at the level of the internal cylindrical periphery 40.

This handling bore is intended to receive a handling bar. Depending on the section of the bar, the section of the bore is adapted. In practice, in the example shown, the section of the bore 24, and therefore of the openings 24a and 24b are circular. In particular, the diameter of the orifices 24a and 24b is between 20 and 30 mm.

As depicted in the Figure 3 , the handling bore 24 has a second orifice 24c emerging radially outwards relative to a longitudinal axis of the body, this second orifice 24c being diametrically opposed to the first orifice 24a.

Preferably, the handling bar is intended to pass through the body 12 through the two diametrically opposed orifices 24a and 24c, the bore 24 therefore also opens out through a fourth orifice 24d located opposite the orifice 24b. This arrangement of the orifices 24a, 24b, 24c and 24d allows a better distribution of the pressure contact points between the handling bar and the body 12. The sections of the orifices 24a, 24b, 24d and 24c are for example identical.

The annular surface 21 of the intermediate collar 15 is located at a distance d1 from the shoulder 19, this distance d1 representing between 100 and 1000% of an axial length d2 of the thread 13, preferably at least 150% of the length d2 . For example, this distance d1 is between 300 and 400 mm. This arrangement makes it possible to leave the jaw 30 around the portion 16, in particular during the operations of unscrewing the lifting plug 10 relative to the tube 8 newly added to the drill string 1. The height d1 is in particular greater than or equal to the sum of the heights of an elevator jaw and the axial length d2 of thread 13.

To allow the lifting plug to be unscrewed, the drill string is lowered, and the blocking table 3 is brought into tight engagement around the new tube 8 added. The lifting plug is then at the height of this blocking table, at human height to allow manipulation via a handling bar. During manual unscrewing, via the handling bar, the lifting plug rises axially relative to the tube 8 and to the blocking table 3. The jaw 30 remaining suspended from the slings 31, the jaw 30 remains a constant altitude relative to the blocking table 4. During its unscrewing, the lifting cap 10 rises relative to the jaw. The intermediate collar makes it possible to limit the axial position of the jaw 30, and thus prevents the jaw 30 left in engagement around the lifting plug 10 from damaging the thread 13.

The body 12 comprises a non-threaded annular portion 25 between the thread 13 and the intermediate collar 15. In this case, this non-threaded annular portion 25 is located between the thread 13 and the annular surface 22 of the intermediate collar 15. This portion non-threaded annular ring 25 makes it possible to give the possibility of increasing the life of the lifting plug, by providing a zone of material allowing a new thread 13 to be machined again. This newly machined thread 13 is then closer to the collar intermediate 15.

Thanks to the lifting plug according to the invention, it is possible to engage the thread 13 in a complementary thread while the plug is retained in the jaw 30 of an elevator. Indeed, the stopper resting on the jaw, this support tolerates rotational driving of the lifting stopper relative to the jaw. The lifting plug is driven in rotation manually using a handling bar introduced into the bore 24, this rotation allowing the thread 13 to be screwed into a complementary threaded portion of a tube to be handled or add to a tubular column.

In practice, the thread 13 is compatible with the threaded portion of the tube to be handled, but the profile of the thread is designed recessed from that of the threaded portion so as to avoid any risk of seizing when screwing the cap onto the tube. In particular, the flanks, the crests and thread roots of the thread 13 are dimensioned so as not to create any interference with the threaded portion of the tube to be handled. On the other hand, the pitch of the thread 13 corresponds to that of the threaded portion of the tube to be handled.

Indeed, the lifting plug must not damage the surfaces of the threaded portion which have been designed to be brought into interference with a complementary threaded portion of a tube with a view to the formation of a train of stems. In the case where the threaded portion provided on the tube to be handled provides surfaces intended to form a seal, in particular seals of the metal-to-metal type, the lifting plug is designed so that it does not have a surface in contact with such sealing surfaces. For example, the lifting plug can be designed to have no surface radially facing such sealing surfaces.

Throughout the description, the expression "comprising a" must be considered as being synonymous with "comprising at least one", unless the contrary is specified.

Claims (10)

1. Lifting plug (10) for lifting a tube string in a gas or oil production well, the plug comprising a body (12) and a screw thread (13) at one axial end (27) of this body to engage by screw-fastening with a threaded portion of a tubular element of the tube string, the body comprising a cylindrical surface (16) able to be placed in a jaw (30) of an elevator (11) of an oil rig, the body comprising two external flanges (14, 15), an upper flange (14) and an intermediate flange (15), which are such that the cylindrical surface of the body is located between the two outer flanges, the upper flange forming a shoulder (19) against which the jaw of the elevator may come to bear, characterized in that the intermediate flange comprises a plug-handling bore (24) allowing a bar that emerges at two distinct points (24a, 24b, 24c, 24d) of the intermediate flange to be inserted through the body.
2. Lifting plug according to Claim 1, characterized in that the handling bore (24) has a first orifice (24a) opening radially to the outside relative to a longitudinal axis of the body.
3. Lifting plug according to Claim 2, characterized in that the handling bore comprises a second orifice (24c) opening radially to the outside relative to a longitudinal axis of the body, this second orifice being diametrically opposite the first orifice (24a).
4. Lifting plug according to any one of the preceding claims, characterized in that the upper flange is positioned at a second end (17) of the body of the plug, which is the opposite end to the end (27) adjacent to the screw thread, relative to a longitudinal axis (X) of the body.
5. Lifting plug according to any one of the preceding claims, characterized in that the intermediate flange (15) is positioned between the cylindrical surface (16) and the screw thread (13).
6. Lifting plug according to any one of the preceding claims, characterized in that the outside diameter of the cylindrical surface (16) is equal to the outside diameter of the tubular element onto which the lifting plug is screwed, notably equal to the nominal outside diameter of this tubular element, some distance from the threaded ends of this tubular element.
7. Lifting plug according to any one of the preceding claims, characterized in that the body is hollow and open at its two longitudinal ends.
8. Lifting plug according to Claim 7, characterized in that a distance (d2) between a shoulder (19) of the upper flange and an annular surface (21) of the intermediate flange facing this shoulder is greater than an axial length (d1) of the screw thread (13), particularly at least 1.5 times greater than this axial length (d1) of the screw thread.
9. Lifting plug according to any one of the preceding claims, characterized in that the lifting plug is made as a single piece.
10. Lifting plug according to any one of the preceding claims, characterized in that the screw thread (13) is formed on the exterior periphery of an exterior surface (26) of the body.

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