NO347248B1

NO347248B1 - Lubricator support tool and method

Info

Publication number: NO347248B1
Application number: NO20220064A
Authority: NO
Inventors: Tomas Johnsen
Original assignee: Stavanger Eng As
Priority date: 2022-01-19
Filing date: 2022-01-19
Publication date: 2023-08-07
Also published as: NO20220064A1; NO20230034A1

Description

LUBRICATOR SUPPORT TOOL AND METHOD

The present invention relates to a tool and a method for use with lubricators used in well operations, and particularly a tool and a method for supporting the lubricator (or parts thereof) during handling of the lubricator.

BACKGROUND

During well operations for example in petroleum production, it is often necessary to temporarily stop production and carry out downhole operations in the well. These are commonly denoted well intervention, and typically carried out using a wireline or coiled tubing which is inserted into the well with tools or equipment attached thereto. Such operations may, for example, be to clean the well, to remove debris or other matter from the well, to inspect the well, to take measurements, or to stimulate the well or reservoir. The tools and equipment may, for example, be so-called tractors, injection heads (for example for injecting chemicals), sensors / measurement equipment, or other types.

In order to gain access to the well, a lubricator is commonly used. The lubricator allows tools or equipment to be inserted into a well safely, by maintaining barriers between the well and the outside environment. The lubricator is typically arranged on top of a valve stack (such as a blow out preventer (BOP)), whereafter valves can be opened and equipment can be deployed into the well.

Publications which may be useful to understand the background include NO 342131 B1, which describes a lubricator-handling device to bring a lubricator string into and out of the well centre; NO 338538 B1; NO 345549 B1; US 2008/0173441 A1, which describes a system and method for deploying one or more tools in a wellbore with a clamp coupled to a flexible interconnect; US 2018/0080291 A1, which describes a snubbing jack and method of snubbing pipe into a well bore; and US 6688394 B1, which describes a continuous circulation drilling method.

SUMMARY

In an embodiment, there is provided a lubricator support tool having first and second lubricator fastener members configured to connect to a lubricator above and below a lubricator connector, wherein a first lubricator fastener member is slidably movable relative to a second lubricator fastener member along an elongate shaft and rotatable relative to the second lubricator fastener member about the shaft, the lubricator support tool further comprising a lock mechanism operable to selectively lock the first lubricator fastener member relative to the second lubricator fastener member such as to prevent relative movement therebetween in at least a longitudinal direction along the shaft.

In an embodiment, there is provided a method of supporting a lubricator during a well intervention operation.

The detailed description below and appended claims outline further embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other characteristics will become clear from the following description of illustrative embodiments, given as non-restrictive examples, with reference to the attached drawings, in which:

Fig.1 is a perspective view of a well intervention setup on a rig deck.

Figs 2-4 illustrate details of the well intervention setup in three operational configurations.

Figs 5-7 show a lubricator support tool in three operational configurations.

Fig.8 illustrates a lubricator support tool.

Fig.9 illustrates details of a lubricator support tool.

DETAILED DESCRIPTION

The following description may use terms such as “horizontal”, “vertical”, “lateral”, “back and forth”, “up and down”, ”upper”, “lower”, “inner”, “outer”, “forward”, “rear”, etc. These terms generally refer to the views and orientations as shown in the drawings and that are associated with a normal use of the invention. The terms are used for the reader’s convenience only and shall not be limiting.

Figure 1 shows a well intervention setup on a rig deck 1. The rig deck 1 may for example be a hatch deck on an offshore petroleum platform. The deck 1 can have multiple slots with removable covers, where some or all slots are located above corresponding wells, extending from the platform into the ground.

For well intervention purposes, a cover may be removed and a BOP 10 arranged on the deck 1 and fixed to a wellhead below the deck 1. A wireline mast 2 having sheaves at its upper section 5 can be positioned adjacent the BOP 10, whereby a wire 3 can be used to lift a lubricator 4 and position the lubricator 4 above the BOP 10. The wireline mast 2 can have a base 6 which is supported on the deck 1, and wherein winches or other equipment is arranged. The wireline mast 2 may comprise additional winches and wires running around sheaves at the upper section 5, whereby a well intervention tool (not shown) can be suspended by a wire extending through the lubricator 4 and the BOP 10 and into the well. Alternatively, winches may be separate from the wireline mast 2 and not positioned in the base 6.

Figs 2-4 illustrate details of the well intervention setup shown in Fig.1. Fig.2 shows the lubricator 4 fixed to the BOP 10. A lower part 4a of the lubricator 4 comprises a strengthened section which is configured for connecting to the BOP 10, and also for splitting the lubricator 4 at the lower part 4a. A connector 4b is foreseen for this purpose. The lower part 4a shown in Fig.2 is also engaged by a lubricator support tool 20, described in further detail below. The lower part 4a may further have fastener profiles (such as flanges and/or support shoulders) and/or strengthened outer surfaces for engagement with the lubricator support tool 20 and/or for other tools or equipment used in splitting the lubricator 4 by operating the connector 4b.

Fig. 3 illustrates the lubricator 4 in the split configuration. In this configuration, the connector 4b has been released (opened) such that the lower part 4a is split into a first section 4c and second section 4d. The second section 4d remains fixed on the BOP 10 in this configuration while the rest of the lubricator 4 is freed from the BOP 10, and supported via the wireline mast 2 and the lubricator support tool 20, described in further detail below. Access to the passage through the BOP 10 and towards the below wellhead and well is in this configuration possible via the upper opening of the second section 4d.

Fig. 4 illustrates the lubricator 4 in the split configuration (as in Fig.3) and with the first section 4c moved to a side relative to the second section 4d. In this configuration, unrestricted vertical access from above is possible into the upper opening of the second section 4d, for example for lowering an elongate, downhole tool into the BOP 10.

During well intervention operations, there may be a need to run and retrieve downhole tools several times. The lubricator 4 may have to be split and made up between each run, for example for access to the downhole tools inside the lubricator 4 and/or the BOP 10. Often, such downhole tools have a length that require them to be assembled from two parts, where one part hangs in the BOP 10 while the second part is positioned inside the lubricator 4 before being connected. An operator may in such a case need to work on the downhole tools inside the lubricator 4 while the lubricator 4 is in the operational configuration shown in Fig.3, i.e. with the lubricator 4 in a split configuration with the second section 4d fixed to the BOP 10 and the first section 4c and the rest of the lubricator 4 suspended directly (vertically) above the second section 4d. Such work may for example involve connecting or disconnecting two parts of a downhole tool through the gap between the first and second sections 4c,d. This can involve health-and-safety (HSE) risks, for example in an event where the wire 3 (see Fig.1) suspending the lubricator 4 breaks or the lubricator 4 (the first section 4c) is unintentionally lowered while such work is ongoing.

Figures 5-7 illustrate the lubricator support tool 20 in the first, second and third operational configuration, corresponding to those operational configurations illustrated in Figs 2, 3 and 4, respectively.

The lubricator support tool 20 comprises a first fastener member 21a configured to engage and fix the lubricator support tool 20 to the lubricator 4 at a position below the connector 4b, i.e. at the second section 4d. A second fastener member 21b is configured to engage and fix the lubricator support tool 20 to the lubricator 4 above the connector 4b, i.e. at the first section 4c.

The first and second fastener members 21a,b may comprise any suitable mechanical connector for rigidly fixing the first and second fastener members 21a,b to the lubricator 4, such as a clamp, gripper, tong, a connection profile, a bolted connection, or the like. It may be manually or automatically actuated to make up the connection when the fastener members 21a,b have been brought into engagement with the lubricator 4, which can for example be done by an operator guiding the tool 20 into the correct position while the tool 20 is suspended by a wire from the mast 2. The lubricator 4 may have prepared profiles and/or connector parts on its outside surface for engagement with the fastener members 21a,b, for example a suitable profile for providing a secure, rigidly fixed connection.

In the examples shown here, the fastener members 21a,b are in the form of bolted clamps extending circumferentially around the lubricator 4 and cooperating with horizontal shoulders on the first and second sections 4c,d in order to provide good vertical load-carrying capability.

As can be seen when comparing Figs 5 and 6, the first lubricator fastener member 21a is movable relative to the second lubricator fastener member 21b in a vertical direction. “Vertical” refers here to the situation when the tool 20 is in use and oriented as shown in the figures, and is then a direction which is parallel to a longitudinal axis of the lubricator 4, which is also arranged substantially vertically when in use. This vertical direction corresponds with a longitudinal axis z of the tool 20 (see Figs 6 and 9). The first and second lubricator fastener members 21a,b are spaced along the longitudinal axis z in order that the tool 20 spans the connector 4b to permit connection above and below the connector 4b. The skilled reader will understand that during handling, transport, etc. of the tool 20, it may be oriented differently.

In the shown example, the second lubricator fastener member 21b is slidably movable relative to the first lubricator fastener member 21a along a shaft 22. The first fastener member 21a is in this example longitudinally fixed relative to the shaft 22.

The tool 20 can thus be connected to the lubricator 4 above and below the lubricator connector 4b while the connector 4b is closed (i.e., the lubricator 4 being in a “nonsplit” configuration) and the second section 4d is fixed to the blow out preventer 10. Optionally, the tool 20 can be arranged on the lubricator 4 before the lubricator 4 is positioned on the BOP 10. By means of the fastener members 21a,b of the tool 20 being longitudinally movable relative to each other, the lubricator connector 4b can be opened or closed, and the first and second sections 4c,d can be moved vertically apart or together, while the tool 20 is connected to the lubricator 4.

Advantageously, by fixing the tool 20 to the second section 4d, which is again fixed (at least indirectly) to the blow out preventer 10, the tool 20 may be configured for supporting the lubricator 4 without engagement with the deck 1. When the tool 20 is fixed to the first and second sections 4c,d, the lubricator 4 is supported from the BOP 10 also when the lubricator connector 4b is released, i.e. the part of the lubricator 4 above the connector 4b is in such a situation not suspended freely from the mast 2 but also remains connected to the blow out preventer 10 via the tool 20.

In the examples shown here, each of the first and second lubricator fastener members 21a,b comprises a clamp part 27a,b configured to fix the respective first and second lubricator fastener members 21a,b to the lubricator 4 by means of a bolted connection.

The fastener members 21a,b may fix the tool 20 to the lubricator at least partly by means of friction force (for example in the case of clamping). Preferably, the lubricator 4 has profiles, such as shoulders, depressions, flanges, or the like, which engage corresponding surfaces on the fastener members 21a,b for load transfer in the vertical direction. This may, for example, be in the form of substantially horizontal shoulders which prevent vertical movement between the fastener members 21a,b and the lubricator 4, when engaged.

The second lubricator fastener member 21b is further rotatable relative to the first lubricator fastener member 21a about a vertical axis, in this case about the longitudinal axis z of the lubricator support tool 20. In the shown example, the shaft 22 and the second lubricator fastener member 21b are rotatable together relative to the first lubricator fastener member 21a. (I.e. the shaft 22 and the second lubricator fastener member 21b are rotationally fixed in relation to each other, such that the second lubricator fastener member 21b is longitudinally slidable along the shaft 22, but not free to rotate about it.) The first lubricator fastener member 21a may be fixed to a base 26 having a motor, such as a hydraulic motor, operable to rotate the shaft 22 relative to the base 26 and the first lubricator fastener member 21a. Alternatively, the relative rotation between the first and second lubricator fastener members 21a,b can be effectuated by an operator, for example by using other tools or equipment on the rig.

A rotational lock, such as a pin or friction lock (e.g. a wedge or clamp), may be arranged to selectively prevent relative rotation between the first and second lubricator fastener members 21a,b, i.e. to lock these in relation to each other. Such a rotational lock may, for example, be arranged in the base 26. Such a lock can be operable to lock the fastener members 21a,b in relation to each other in one or more of the operational configurations shown in Figs 5-7.

In this example, one of the first and second lubricator fastener members 21a,b (here, the first lubricator fastener members 21a) is longitudinally fixed relative to the shaft 22, and the other of the first and second lubricator fastener members 21a,b (here, the second lubricator fastener members 21b) is rotationally fixed relative to the shaft 22. The skilled reader will, however, understand that in other examples, one of the first and second lubricator fastener members 21a,b may be both rotationally and longitudinally fixed to the shaft 22, while the other of the first and second lubricator fastener members 21a,b is both rotationally and longitudinally movable relative to the shaft 22.

Referring now again to Figs 2-4, when carrying out an operation in which the lubricator 4 needs to be split by opening the connector 4b, the tool 20 may be arranged on the lubricator 4 with the first and second lubricator fastener members 21a and 21b fixed to the first and second sections 4d and 4c, respectively. This is shown in Fig.2, and corresponds with the tool 20 being in the operational configuration shown in Fig.5.

The lubricator connector 4b can now be opened for splitting the lubricator 4, and the lubricator 4 lifted, for example by means of the wire 3. The second section 4d will remain fixed to the blow out preventer 10, while the rest of the lubricator 4 will be vertically lifted. This situation is shown in Fig.3, and the tool 20 will be in the operational configuration shown in Fig.6. In this configuration, an operator may carry out work on a tool positioned inside the lubricator 4 and/or the blow out preventer 10 in the gap between the first and second sections 4c,d as described above.

The lubricator 4 (with the exception of the second section 4d) may thereafter be moved (i.e. swung or pivoted) to the side to further improve access to the well. This operational configuration is shown in Figs 4 and 7.

Illustrated in Fig.9, the tool 20 may further comprise a lock mechanism 40 operable to lock the second lubricator fastener member 21b relative to the first lubricator fastener member 21a and prevent relative movement therebetween. The locking mechanism 40 can prevent relative vertical movement between the first and second lubricator fastener members 21a,b, i.e. in a direction parallel to the longitudinal axis z.

This may provide enhanced safety in the operational configuration shown in Figs 3 and 6, when an operator may need to carry out work in the gap between the first and second sections 4c,d, as described above. By having a lock mechanism 40, additional security is provided against an undesirable situation where the first section 4c is unintentionally lowered while such work is being carried out, for example if the wire 3 breaks.

The lock mechanism 40 may for this purpose for example comprise a lock piston 42 operable to engage a lock profile 41, as illustrated in Fig.9. In this example, the lock piston 42 is arranged as part of the second lubricator fastener member 21b and the lock profile 41 is provided on the shaft 22. The lock profile 41 in this example comprises an elongate serrated surface along at least a part of the length of the shaft 22, and the lock piston 42 comprises a corresponding serrated surface for engagement with the serrated surface of the lock profile 41.

The skilled reader will understand that various alternative mechanical locking mechanisms may be available to obtain the same effect, for example locking pins, friction locks (such as a wedge or clamp), a lead screw / trapezoidal screw or other types. A hydraulic cylinder (for example as described below) may also form a lock mechanism for this purpose.

The lock mechanism 40 may be arranged as a ratchet mechanism (such as a sawtooth lock profile 41, as illustrated), permitting motion in which the first and second lubricator fastener members 21a,b moves away from each other, while preventing motion in the other direction. This is illustrated in Fig.9 by means of the double arrow D. Forming the lock profile 41 and the corresponding surface on the piston 42 as a ratchet, as can be seen in Fig.9, can allow relative movement in the direction of the double arrow, e.g. when the lubricator is brought from the operational configuration in Fig.2 to that in Fig.3, but prevent a return (downward) motion. A manual release can be provided as part of the ratchet mechanism for the purpose of allowing such return motion, for example when manual work in the gap between the first and second sections 4c,d has been completed and the lubricator 4 should be re-assembled by connecting the first and second sections 4c,d by connector 4b. The manual release may, for example, comprise a lever to retract and hold the lock piston 42 away from the lock profile 41. Optionally, the lock mechanism 40 may be a different type of one-way longitudinal lock, such as a hydraulic circuit having a one-way valve permitting movement of a hydraulic cylinder (e.g. such as the hydraulic cylinder 30 illustrated in Fig.8) in one direction but blocking return motion by preventing outflow of hydraulic fluid from one of the cylinder chambers.

The lock piston 42 may, for example, be operated by a spring or other type of elastic member, continuously urging the lock piston 42 towards the lock profile 41. Such an arrangement may be particularly beneficial if the lock mechanism 40 comprises a ratchet mechanism, as described above. Alternatively, or additionally, the lock piston 42 may be manually operated, for example by an operator or by hydraulics, to bring or force the lock piston 42 into a locked position when the tool 20 has been placed in the desired operational configuration in which it should be locked (such as that shown in Figs 3 and 6).

The lock mechanism 40 may, additionally or alternatively, be configured to prevent relative rotational movement between the first and second lubricator fastener members 21a,b about a vertical axis, i.e. an axis parallel to the longitudinal axis z. It may, for example, be beneficial to arrange the tool 20 to lock the first and second lubricator fastener members 21a,b relative to each other both longitudinally and rotationally in the operational configuration shown in Figs 4 and 7.

In some examples, the tool 20 may comprise a linear actuator 30 operable to produce a force urging the first lubricator fastener member 21a away from the second lubricator fastener member 21b in the longitudinal direction. Illustrated in Fig. 8, the linear actuator 30 can be fixed to the first lubricator fastener member 21a via a connector 30b, and may have a shaft engagement member 30a operatively engaging the shaft 22. In this example, the shaft engagement member 30a operatively engages the shaft 22 at an end part 22a of the shaft 22 such as to produce a longitudinal force on the shaft 22. Alternatively, the linear actuator 30 may engage the first and/or second lubricator fastener members 21a,b at other positions, or indirectly via other elements, such as the base 26.

The linear actuator 30 may thus be operable to move the tool 20 from the operational configuration shown in Figs 2 and 5, to the operational configuration shown in Figs 3 and 6 by means of a force produced by the actuator 30.

The shaft engagement member 30a can permit rotation of the shaft 22 relative to the shaft engagement member 30a, for example wherein the shaft engagement member 30a engages an end surface of the shaft 22 and/or wherein the tool 20 comprises an insert between the shaft engagement member 30a and the end part 22a permitting such rotation.

The linear actuator 30 may, for example, be a hydraulic piston-cylinder actuator, a lead (trapezoidal) screw, or an electric actuator. It may be manually or automatically operated.

By means of the linear actuator 30, a force can be produced to assist in lifting the lubricator 4 after the connector 4b has been opened, i.e. to raise the first section 4c in relation to the second section 4d. Such lifting may alternatively be done via the wire 3, or by other means, such as a dedicated crane or hoisting assembly.

The linear actuator 30 may, additionally or alternatively, provide a securing (locking) function when the lubricator 4 and the tool 20 are in the operational configuration shown in Figs 3 and 6. By operating the linear actuator 30 to maintain a force urging the first and second lubricator fastener members 21a,b apart, additional safety can be provided in an event where for example the wire 3 breaks, as the linear actuator 30 could then prevent the first section 4c from lowering towards the second section 4d while manual work is being carried out in the gap between these.

The same can be achieved if the linear actuator 30 is provided with a lock, such as a hydraulic lock or a mechanical lock, which can fix the linear actuator 30 in a position as shown in Fig.6.

According to the present disclosure, support for a lubricator 4 may be provided in a more efficient manner, e.g. to provide a tool which is easier to handle on the rig deck 1, while providing the abovementioned safety functionality when operators are carrying out operations on the lubricator 4 or related equipment such as downhole tools in the blow out preventer 10 and/or the lubricator 4. Embodiments according to the present disclosure can thus provide a significantly reduced HSE risk since the upper part of the lubricator 4 can be secured from dropping.

Claims

1. A lubricator support tool (20) having a first lubricator fastener member (21a) and a second lubricator fastener member (21b), characterised in that the first lubricator fastener member (21a) is configured to connect to a lubricator (4) below a lubricator connector (4b) and the second lubricator fastener member (21b) being configured to connect to the lubricator (4) above the lubricator connector (4b),

wherein the first lubricator fastener member (21a) is slidably movable relative to the second lubricator fastener member (21b) along an elongate shaft (22) and rotatable relative to the second lubricator fastener member (21b) about the shaft (22),

the lubricator support tool (20) further comprising a lock mechanism (40) operable to selectively lock the first lubricator fastener member (21a) relative to the second lubricator fastener member (21b) such as to prevent relative movement therebetween in at least a longitudinal direction along the shaft (22).

2. The lubricator support tool (20) according to claim 1, wherein the lock mechanism (40) is arranged to selectively prevent relative rotation between the first and second lubricator fastener members (21a,b) about the shaft (22).

3. The lubricator support tool (20) according to any preceding claim, wherein the lock mechanism (40) is a one-way longitudinal lock configured to permit motion (D) in which the first and second lubricator fastener members (21a,b) move longitudinally away from each other but to prevent motion (D) in which the first and second lubricator fastener members (21a,b) move towards each other.

4. The lubricator support tool (20) according to any preceding claim, wherein the lock mechanism (40) comprises a lock piston (42) operable to engage a lock profile (41) on the shaft (22).

5. The lubricator support tool (20) according to any preceding claim, wherein the first lubricator fastener members (21a) is longitudinally fixed relative to the shaft (22) and the second lubricator fastener members (21b) is rotationally fixed relative to the shaft (22).

6. The lubricator support tool (20) according to any preceding claim, comprising a linear actuator (30) operable to produce a force urging the first lubricator fastener member (21a) away from the second lubricator fastener member (21b) in the longitudinal direction along the shaft (22).

7. The lubricator support tool (20) according to any preceding claim, wherein the lubricator support tool (20) is configured for supporting the lubricator (4) when the lubricator (4) is mounted on a blow out preventer (10) and without engagement with a rig deck (1).

8. A method of supporting a lubricator (4) during a well intervention operation, the method characterised by:

arranging a support tool (20) having a first lubricator fastener member (21a) and a second lubricator fastener member (21b) slidably movable relative to the first lubricator fastener member (21a) along an elongate shaft (22) and rotatable relative to the first lubricator fastener member (21a) about the shaft (22), the first lubricator fastener member (21a) connected to a lubricator (4) below a lubricator connector (4b) and the second lubricator fastener member (21b) connected to the lubricator (4) above the lubricator connector (4b); splitting the lubricator (4) by operating the lubricator connector (4b) and moving a first section (4c) of the lubricator (4) away from a second section (4d) of the lubricator (4);

by means of a lock mechanism (40) on the tool (20), preventing relative vertical movement between the first lubricator fastener member (21a) and the second lubricator fastener member (21b) while carrying out work in a gap between the first and second sections (4c,d);

rotating the first lubricator fastener member (21a) relative to the second lubricator fastener member (21b) about the shaft (22) to move the first section (4c) horizontally relative to the second section (4d).

9. The method according to claim 8, further comprising:

driving the first lubricator fastener member (21a) away from the second lubricator fastener member (21b) by means of an actuator (30) on the tool (20), such as to move the first section (4c) of the lubricator (4) away from the second section (4d).

10. The method according to any of claims 8-9, wherein the tool (20) is a tool according to any of claims 1-7.