A slick joint

Abstract

A slick joint 10 comprising a housing 30, 40 configured to receive a continuous communication line 20 which passes through the slick joint. Preferably, the housing comprises a main body 30 and a cover

Description

Technical Field This disclosure relates to a slick joint. In particular it relates to a slick joint that comprises a housing configured to receive a continuous communication line (e.g., a hydraulic control line or hydraulic monitoring line). Background Control and monitoring systems are used by rig personnel to control the operation of a well, as well as to monitor its performance. Typically, the control and monitoring system between the rig and the wellhead is primarily hydraulic. Control and / or monitoring can be achieved with the transmission of signals down the well from the rig. Control signals may be transmitted via hydraulic control lines (HCLs) and monitoring signals are transmitted via hydraulic monitoring lines (HMLs). Resources are invested in setting up hydraulic lines, so that during use, downhole devices can be efficiently controlled and monitored. An umbilical cable which includes a number of hydraulic lines will typically pass from the rig above sea level down towards the wellhead at the seabed. Accordingly, an operator on the rig above the water surface can control underwater equipment, including equipment that is below the seabed. Once the umbilical cable is in place, signals pass down the hydraulic lines along the length of the pipe from the rig towards the seabed. Control signals can pass below the seabed in order to control equipment that is inside the well. Monitoring signals can pass upwards from the well in order to monitor the well equipment, and also can be used to monitor the well itself. Once the equipment has been installed in place, the hydraulic lines are established. The umbilical cable includes several metal hydraulic lines encased within a ‘flat-pack’ polymer housing. Thus, the umbilical cable comprises a number of hydraulic lines, each of which is protected by an outer sheathing. Each of the hydraulic lines acts as a communication conduit for a given downhole device. The encapsulated hydraulic lines pass through a tension table that is seated on the rig floor and designed to suit the riser system. During typical operations, the umbilical cable continues into and through a blow out preventer (BOP) until it is terminated at a slick joint. The control system is to be arranged so that signals can be transmitted to equipment that is downstream of this slick joint. Ported slick joints include ports which typically receive hydraulic fluid in order to allow the transmission of control signals and monitoring signals. Establishing the control and monitoring system is a complex process due to the equipment being deep below sea level. Connecting the umbilical cable to the slick joint typically involves stripping back part of the outer sheathing, and fixing a hydraulic fitting to each of the hydraulic lines (HCLs &HMLs) to the slick joint, by means of off-the-shelf hydraulic fittings. As a consequence, each hydraulic line is cut to a specific length, and so is not transferable between rigs. This is time consuming and costly. There is a demand for a non-ported slick joint that eliminates the need to break the hydraulic lines. Innovation is to be found in simplifying the process of providing control and monitoring systems within a well. Disclosure is provided of efficiency savings, which serve to reduce costs, speed up the installation of a functioning well, and provide environmental benefits by ensuring that control system apparatus is reusable. Summary Aspects of the present invention are set out by the claims. Further aspects are also described. As a first aspect, disclosure is provided of a slick joint (10) comprising a housing (30, 40) configured to receive a continuous communication line (20) which passes through the slick joint (10). Slick joints usually receive a plurality of communication lines, which allows control and monitoring of various pieces of equipment. Examples of communication lines include hydraulic control lines (HCLs) and hydraulic monitoring lines (HMLs), as well as electrical lines and gas lines. Typically, the housing will be configured to receive a plurality of HCLs and a plurality of HMLs, in order to facilitate the control and monitoring of the well. The communication line is continuous in the sense that the communication line is not broken in order for the slick joint to be installed with the communication line. A non-ported slick joint is achieved, in response to demand for jack up based subsea developments. The slick joint is non-ported because it accommodates the communication line, and therefore the slick joint doesn’t include any integral communication lines. This is in contrast to ported slick joints, which allow materials - typically fluids - to be introduced or removed from the interior of the pipe, or for internal pressure to be measured. Accordingly, disclosure is provided of a slick joint that includes continuous HCLs, continuous HMLs, continuous electrical lines, and continuous gas lines. These continuous communication lines can be simply installed within the non-ported slick joint. Typically, jack up deployed subsea drilling riser services cover all elements during the drilling phase, such as the riser package itself, rig modification, tension systems, interface management and running procedures. However, during the completion phase of the project there may be some gaps. The gap in the service offering for jack up subsea operations is as follows: • Ported slick joints make use of bespoke lengths of umbilical between the surface BOP and the tubing hanger running tool (THRT). • There is no way to test the THRT and not break the umbilical out before running. This presents a serious risk that the lines could be crossed causing a malfunction or worse a dropped tubing string. • There is a demand to prevent down time and other list time incidents, which may occur when using a ported slick joint designed for a fixed position with a subsea BOP for a surface BOP subsea application. The housing may comprise a main body (30) and a cover plate (40). Advantageously, the main body and cover plate are configured to receive the continuous communication line, so that it passes through the slick joint. During use, the housing encloses the communication line, protecting it so that communication signals can be transmitted, which allows well equipment to be controlled and monitored. The non-ported slick joint accommodates a communication line which passes between the main body and the cover plate. Thus, the communication line is continuous, rather than a ported slick joint for which the communication line is broken in order to attach it to ports of the slick joint. Optionally, the slick joint further comprises fasteners (31, 41) configured to hold together the main body (30) and the cover plate (40). Advantageously, the fasteners hold together the housing around the communication line to provide a non-ported, in contrast with a ported slick joint for which the communication line is attached to ports of the slick joint. Optionally, the cover plate (40) includes a recess (42) configured to receive the communication line (20). Advantageously, the communication line can be protected because it is received within the recess of the cover plate. Furthermore, it is simple for the communication line to be installed into the slick joint by inserting the communication line into the recess of the cover plate, and then attaching the cover plate to the main body. Optionally, the slick joint (10) further comprises a seal (21) configured to surround the communication line (20) within the recess (42) of the cover plate (40). Advantageously, the seal is configured to protect the communication line when it is installed in the slick joint. Optionally, the cover plate (40) and main body (30) are attached by a hinge joint (45). The hinge joint allows the cover plate and main body to move between an open position and a closed position. Advantageously, a hinge joint allows the slick joint to be easily opened and closed, providing a simple way for the communication line to be installed so that it passes through the slick joint. Optionally, the slick joint further comprises a number of cross seals (32). The cross seals (32) are configured to seal the main body (30) and the cover plate (40). Advantageously, the cross seals hold in position the main body relative to the cover plate, thus protecting the communication line from damage. Optionally, each cross seal (32) serves to form a seal between the slick joint (10) and a blow out preventer (100) which is configured to receive the slick joint (10). Advantageously, the cross seals further serve to hold in position the slick joint relative to the blow out preventer, further protecting the communication line from damage. Optionally, each cross seal (32) extends across a surface of the main body (30), each cross seal (32) having two ends which are arranged on an outside of the main body (30) when the cover plate (40) has been placed over the main body (30). Advantageously, each cross seal serves to provide a single seal which holds in place the communication line relative to the housing of the slick joint, and also holds in place the slick joint relative to the blow out preventer. Optionally, the communication line (20) is protected by a sheath (20’). Advantageously, the sheath is an integral part of the communication line which is configured to protect it from damage during use. Optionally, the slick joint further comprises a connector (33) configured to connect as part of a riser string, wherein the connector (33) has a space (34) which allows the communication line (20) to pass through. Advantageously, the connector is used to attach the slick joint to the rest of the riser string, with the connector being arranged to accommodate the communication line. The riser string (which may be referred to as a landing string) serves as a conduit from the wellhead at the seabed to the rig at the surface. Optionally, the connector (33) is configured so that it cannot be rotated with respect to the rest of the slick joint (10). Advantageously, providing a connector that doesn’t rotate ensures that the communication line will be held securely without being damaged if the slick joint is impacted by a twisting force. Optionally, the slick joint (10) is configured to be received by a blow out preventer (100). Advantageously, the slick joint can be arranged to ensure that the communication line can pass through the blow out preventer. As a second aspect, disclosure is provided of a control and monitoring system comprising a slick joint (10) according to the first aspect. Advantageously, the slick joint can be used to establish communication lines (e.g., hydraulic control lines, hydraulic monitoring lines, electrical lines, gas lines), which can be used to control and monitor well apparatus. Brief Description of the Drawings Embodiments will now be described, by way of example only, with reference to the accompanying drawings, in which: • FIG. 1 provides a plan view of a slick joint; • FIG. 2 provides a plan view of the slick joint, shown with an installed umbilical cable; • FIG. 3 provides a side view of the slick joint; • FIG. 4 provides a perspective view of the slick joint; • FIG. 5 provides a perspective view of the slick joint, shown from another angle; • FIG. 6 provides a perspective view of the slick joint, shown installed with the umbilical cable; • FIG. 7 provides a perspective view of the slick joint, shown with part cut away to reveal the umbilical cable housed between a main body and a cover plate; • FIG. 8 provides a perspective view of the main body of the slick joint, with the cover plate removed; • FIG. 9 provides a perspective view of the cover plate of the slick joint; • FIG. 10 provides a first cross-sectional view of the slick joint, illustrating a cross seal configured to grip the umbilical cable between the main body and the cover plate; • FIG. 11 provides a second cross-sectional view of the slick joint, illustrating fasteners configured to secure the main body and the cover plate; • FIG. 12 provides a flow chart illustrating how the slick joint is to be installed; • FIG. 13 provides a perspective view of the slick joint in an open position, with the cover plate arranged to move with respect to the main body via a hinge joint; • FIG. 14 provides a perspective view of the slick joint in a closed position, shown installed with the umbilical cable; • FIG. 15 provides an end-on view of the slick joint, showing the umbilical cable including six individual cores; • FIG. 16 provides a close-up view of the umbilical cable which includes six individual cores; • FIG. 17 provides a perspective view of a blow out preventer which is configured to be installed with the slick joint; and • FIG. 18 provides a cross-section view of the blow out preventer which has been installed with the slick joint. Detailed Description Various exemplary embodiments, features, and aspects are described in detail below with reference to the drawings. FIGs. 1-11 &13-16 provide various views of a non-ported slick joint 10. FIGs. 1-3 show how the slick joint 10 is oriented during use, with the slick joint 10 shown arranged substantially vertically. An upper end 11 of the slick joint is configured to attach to a pipe that extends from the rig down towards the seabed. A lower end 12 of the slick joint is configured to attach to the wellhead. . FIGs. 2, 6-11, &14-16 illustrate the slick joint 10 installed with an umbilical cable 20. The umbilical cable 20 includes one or more hydraulic lines 20. This may include one or more hydraulic control line (HCL) 20 and / or one or more hydraulic monitoring line (HML) 20. Thus, the hydraulic lines 20 can be used to control equipment that is below the slick joint, such as the wellhead. Furthermore, the hydraulic lines 20 can be used to monitor the equipment, as well as the well itself. In addition, a hydraulic line 20 may serve as both a HCL and a HML, with the pressure in the cable being used to transfer a control signal to equipment below the surface, with a drop in pressure being detected at the surface indicating an issue with this equipment. The umbilical cable 20 includes a sheath 20’ which serves to protect each hydraulic line during use. In addition to hydraulic lines, the umbilical cable 20 may further include gas lines and electrical lines. Typically, the umbilical cable 20 that includes a plurality of hydraulic lines which are surrounded by the sheath 20’. The slick joint 10 includes a main body 30 and a cover plate 40, which during use serve as a housing that protects the hydraulic line 20. FIG. 8 illustrates the main body 30, and FIG. 9 illustrates the cover plate 40. For the example shown, the slick joint 10 has a two-metre removable cover plate section 40. The cover plate 40 extends along the length of the slick joint 10. When installing the control system, the hydraulic line 20 is received between the main body 30 and the cover plate 40. FIG. 12 illustrates a method S10 of installing the slick joint, according to the following steps: • In step SI, a pipe from the sea surface is attached to the main body of the slick joint. • In step S2, a communication line (typically including HCLs and HMLs), is installed down the pipe into the well. • In step S3, the communication line is received by the cover plate of the slick joint. • In step S4, the cover plate is attached to the main body. As an alternative, the cover plate and main body may be attached together via a hinge joint, which allows the slick joint to be arranged in an open position and a closed position (see FIGs. 13 &14). • In step S5, the main body of the slick joint is placed into the blow out preventer (BOP), so that during use, the control line runs through the BOP. Thus, a slick joint is provided that is configured to receive an existing communication line, rather than including an integral communication line. Accordingly, the communication line runs continuously through this non-ported slick joint, which provides a simpler arrangement compared to a ported slick joint, for which the communication line is broken in order to attach it to ports of the slick joint. After use, the reverse process is followed in order to remove the communication line from the slick joint. Since the communication line isn’t cut to size in order to install it with the slick joint, the communication line can be reused at a different location. Thus, environmental benefits and cost benefits are achieved by virtue of providing reusable equipment. FIGs. 13 &14 illustrate an example for which the slick joint 10 can be moved between an open position and a closed position. The slick joint 10 includes a hinge joint 45, about which the cover plate 40 and main body 30 can rotate relative to one another. When installing the hydraulic line 20, the cover plate 40 can be moved to the open position with respect to the main body 30, and once the hydraulic line 20 has been installed in the recess 42, the cover plate 40 is moved to the closed position. When removing the hydraulic line 20, the cover plate 40 can be moved to the open position with respect to the main body 30, and once the hydraulic line 20 has been removed from the recess 42, the cover plate 40 is moved to the closed position. FIGs. 15 &16 provide an end-on views of the slick joint 10. FIG. 16 provides a close-up view of the umbilical cable which in this example includes six individual cores. Each of the cores corresponds to a different communication line 20, which can be used to send a control signal from the rig to some well equipment, or a monitoring signal from the well equipment to the rig. The communication lines 20 are enclosed by a sheath 20’. The umbilical 20 may be referred to as a communication line, although it will be understood that the umbilical typically will comprise a plurality of communication lines, in this case six. The umbilical cable 20 is surrounded by a seal 21 in order to provide protection it when it is installed in the slick joint 10. FIGs. 17 &18 illustrate a blow out preventer (BOP) 100. FIG. 17 provides a perspective view of a BOP 100 configured to be installed with the slick joint 10. FIG. 18 provides a cross-section view showing the BOP 100 installed with the slick joint 10. The BOP 100 includes an annular 110 which holds the slick joint 10 in place. Once the slick joint 10 has been inserted into the BOP 100, the piston rises, and then a packer 120 squashes in all around it, to ensure that the slick joint 10 is held in place. FIG. 17 shows the BOP with the piston down and the packer 120 uncompressed. The cross seals 32 of the slick joint 10 serve to form a seal with the annular 110 in order to hold the slick joint in place. Each cross seal 32 serves to form a seal between the slick joint 10 and a blow out preventer 100 which is configured to receive the slick joint 10. Each cross seal 32 extends across a surface of the main body 30. Each cross seal 32 has two ends which are arranged on an outside of the main body 30 when the cover plate 40 has been placed over the main body 30. The cross seals 32 function to provide grip between the slick joint 10 and the annular 110 of the BOP 100, because each of the cross seals 32 has 2 ends which emerge out of the exterior of the slick joint 10. Each cross seal is typically formed from rubber, and may be made from an O ring. The slick joint 10 allows the umbilical 20 to run through the slick joint 10, without the umbilical 20 being cut and terminated, and then re-terminated. The slick joint 10 comprises a connector 33 configured to connect with the BOP 100. The connector 33 includes a space 34 that allows the umbilical 20 to pass through. The connector 33 can be rotated with respect to the rest of the slick joint 10, which allows the slick joint 10 to be made up without rotating the whole of the main body 30. The design includes a cover plate 40 that allows the umbilical 20 to be housed between the main body 30 and the cover plate 40. The annular BOP 110 seals on the outside and O-ring cords and elastomeric ‘slab’ seal 32 is between the cover plate 40 and main body 40 to form a seal around the umbilical 20. The ’slab’ seal 32 has special sealing elements that allow compression on the umbilical 20 to form a seal and also prevent hydraulic lock. Fasteners 31 of the main body 30 of the slick joint 10 correspond to fasteners 41 of the cover plate 40, such that during use, the fasteners (31, 41) hold together the main body 30 and the cover plate 40. Thus, the cover plate 20 is held in place using a series of fasteners (twenty in this instance). A recess 42 of the cover plate 40 of the slick joint 10 accommodates the hydraulic line 20. Thus, the cover plate 40 features a seat 42 within which the umbilical seal 21 sits. The umbilical 20 locates inside the umbilical seal 21. This design prevents pressurised fluid from passing around the outside of the umbilical 20, and allows an annular BOP fixture 110 to seal around the slick joint 10 while not damaging the control umbilical 20. The slick joint 10 features a series of cross seals 32 that prevent pressurised fluid passing at the interface between the cover plate 40, main-body 30, and umbilical seal 21. FIGs. 1-5 show nine spaces running vertically between the fasteners (31, 41), and FIG. 8 shows an example for which between the fasteners (31, 41), the cross-seals 32 are arranged in groups of three. Accordingly, a possible arrangement is to provide cross-seals 32 that are arranged in nine groups of three. As an alternative, the cross-seals 32 may be arranged into nine groups of twelve. It is possible for the annular BOP fixture 110 to seal around the slick joint 10 when positioned over the cover plate 30. Thus, when the annular BOP fixture 110 is closed and in contact with the ends of the cross-seal 32, it also provides a seal at the outer edges of the interface between the cover plate 40 and the main body 30. Although the disclosed subject matter has been described using specific terminology relating to apparatus features and / or method features, it is to be understood that the claimed subject matter is not necessarily limited to the examples disclosed. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions. The advantages disclosed may relate to several of the examples that are disclosed.

Claims

1. A slick joint (10) comprising a housing (30, 40) configured to receive a continuous communication line (20) which passes through the slick joint (10).

2. The slick joint (10) according to claim 1, wherein the housing comprises a main body (30) and a cover plate (40).

3. The slick joint (10) according to claim 2, further comprising fasteners (31, 41) configured to hold together the main body (30) and the cover plate (40).

4. The slick joint (10) according to claim 2 or claim 3, wherein the cover plate (40) includes a recess (42) configured to receive the communication line (20).

5. The slick joint (10) according to claim 4, further comprising a seal (21) configured to surround the communication line (20) within the recess (42) of the cover plate (40).

6. The slick joint (10) according to any one of claims 2 to 5, wherein the cover plate (40) and main body (30) are attached by a hinge joint (45).

7. The slick joint (10) according to any one of claims 2 to 6, further comprising a number of cross seals (32) configured to seal the main body (30) and the cover plate (40).

8. The slick joint (10) according to claim 7, wherein each cross seal (32) serves to form a seal between the slick joint (10) and a blow out preventer (100) which is configured to receive the slick joint (10).

9. The slick joint (10) according to claim 7 or claim 8, wherein each cross seal (32) extends across a surface of the main body (30), each cross seal (32) having two ends which are arranged on an outside of the main body (30) when the cover plate (40) has been placed over the main body (30).

10. The slick joint (10) according to any preceding claim, wherein the communication line (20) is protected by a sheath (20’).

11. The slick joint (10) according to any preceding claim, further comprising a connector (33) configured to connect as part of a riser string, wherein the connector (33) has a space (34) which allows the communication line (20) to pass through.

12. The slick joint (10) according to claim 11, wherein the connector (33) is configured sothat it cannot be rotated with respect to the rest of the slick joint (10).

13. The slick joint (10) according to any preceding claim, comprising a plurality of hydraulic control lines (20) and a plurality of hydraulic monitoring lines (20).

14. The slick joint (10) according to any preceding claim, wherein the slick joint (10) is configured to be received by a blow out preventer (100).

15. A control and monitoring system comprising a slick joint (10) according to any preceding claim.

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