WO2011036175A1

WO2011036175A1 - Annulus access tool

Info

Publication number: WO2011036175A1
Application number: PCT/EP2010/063972
Authority: WO
Inventors: André M. SMITH; Jarmo Kekarainen
Original assignee: Aker Subsea As
Priority date: 2009-09-22
Filing date: 2010-09-22
Publication date: 2011-03-31

Abstract

Access and alignment tool (1), suitable for providing a wire suspended subsea arrangement, such as a plug running tool, with access and alignment to the annulus bore (15) in a tubing hanger (3) or a Xmas tree having a production bore (13) and an annulus bore (15). The tool (1) exhibitsan elongated shape with an inner guiding channel(9), said guiding channel (9) having an upper receiving aperture(9a) and a lower aperture (9b). The lower aperture (9b) is adapted to be arranged directly above and aligned with the annulus bore (15) when the access and alignment tool (1) is installed above the annulus bore (15), which access and alignment tool (1) is suitable to be run through a monobore riser. The tool (1) is adapted to provide a sealed connection between said guiding channel (9) and the annulus bore (15). It comprises a fluid exit bore (45) adapted for communicating fluid with said production bore (13). Fig. 2

Description

Annulus access tool

The present invention relates to an annulus access and alignment tool for providing a wireline tool access to an annulus bore through a marine riser.

Background

For accessing the annulus bore of a tubing hanger or a vertical Xmas tree through a mono-bore riser, a way of guiding to the annulus bore is required. I.e. one needs a way of distinguishing between the production bore and the annulus bore and to align with the annulus bore.

Patent publication US 5,941 ,310 describes a monobore riser system with a bore selector. With the bore selector, the production or the annulus bore of the tubing hanger can be chosen selectively for communication access of fluid or wireline tools.

Patent publication US 6,109,353 describes a mono-bore riser system based on a dual bore completion tree. An annulus plug is moveable between a first and second position, wherein in a first position fluid can flow past the plug in the annulus bore and in the second position it can not.

Furthermore, the company Neptune Subsea Engineering (previously Subsea Engineering Services) has disclosed an annulus access tool adapted for use in a mono-bore riser. The tool is used to provide aligned access to the annulus bore of a tubing hanger having a production bore and an annulus bore. It has an elongated shape with an inner guiding channel, said guiding channel having an upper receiving aperture and a lower aperture, which lower aperture is adapted to be arranged directly above and aligned with the annulus bore when the annulus access alignment tool is installed above the tubing hanger. A description can be found on www.subsea.org.uk.

The invention

According to a first aspect of the present invention, there is provided an access and alignment tool suitable for providing a wire suspended subsea arrangement, such as a plug running tool, with access and alignment to the annulus bore in a tubing hanger or a Xmas tree having a production bore and an annulus bore. The tool exhibits an elongated shape with an inner guiding channel . The guiding channel has an upper receiving aperture and a lower aperture. The lower aperture is adapted to be arranged directly above and aligned with the annulus bore when the access and alignment tool is installed above the annulus bore. The access and alignment tool is suitable to be run through a monobore riser. According to the invention, the access and alignment tool is adapted to provide a sealed connection between said guiding channel and the annulus bore.

With such a sealed connection, the operator is able to perform pressure testing of the plug when installed through the tool. Without the sealed connection, he would have to retrieve the tool and perform pressure testing with a dedicated auxiliary tool.

Preferably, the tool according to the invention comprises a stinger adapted to enter into said annulus bore. The stinger is provided with at least one seal adapted to provide the sealed connection between the inner guiding channel of the tool and the annulus bore.

According to a preferred embodiment of the present invention, the tool comprises a circulation duct which is adapted to provide fluid communication between the guiding channel and the production bore. The circulation duct ends in an aperture arranged so as to flush and/or circulate liquid through the upper part of the production bore when liquid is flown through the circulation duct in direction from the guiding channel.

This preferred embodiment can advantageously comprise means for closing the flushing channel for fluid communication through the circulation duct. The means is preferably adapted to be opened by the operator.

The said means can comprise a burst disc which is adapted to break at a predetermined pressure drop over it. Furthermore, the tool can advantageously comprise a nozzle in connection with the said circulation duct. The nozzle is preferably adapted to provide a jet of liquid into the upper part of the production bore. According to a further advantageous embodiment of the present invention, the access and alignment tool comprises locking means adapted to lock to an internal locking profile of the tubing hanger or Xmas tree. By locking the tool to the tubing hanger or Xmas tree, the operator will not have the problem with maintaining the tool in a constant position during bad surface weather.

According to a second aspect of the present invention, there is provided a method of inserting a plug into an annulus bore after having guided the plug through an access and alignment tool according to the first aspect of the invention. According to the second aspect of the invention, the method comprises forcing the plug into the annulus bore by applying pressure above it, through the guiding channel of said access and alignment tool. The operator can apply such pressure through a riser extending to a surface installation.

With appropriate adaptation of other parts of the well equipment, a person skilled in the art will appreciate the flow of fluid through the circulation channel can flow in both directions. Thus, the flow direction can be away from the upper part of the production bore, when circulating through the circulation channel.

Example of embodiment

Having described the main features of the present invention, a more detailed example of embodiment will now be given with reference to the drawings, in which

Fig. 1 is a perspective view of a tool according to the present invention,

arranged above a tubing hanger;

Fig. 2 is a cross section view of the tool shown in Fig. 1 ;

Fig. 3 is a cross section view of the lower part of the tool partly landed in the tubing hanger of Fig. 1 ; Fig. 4 is a cross section view of the lower part of the tool fully landed and oriented, but not yet locked to the tubing hanger;

Fig. 5 is a cross section view of the lower part of the tool, during circulation of fluid down the annulus and up through the production bore.

Fig. 1 shows an annulus access and alignment tool 1 according to an

embodiment of the present invention. The tool 1 is arranged above, but not yet landed in a subsea wellhead 2 (Fig. 5) with a tubing hanger 3. Not shown is a mono-bore workover riser extending up to the surface and surrounding the tool 1 . Also between the riser and the well head is a blow out preventer (BOP) 4 (Fig. 5) surrounding the tool 1 .

The tool 1 comprises a casing 5, above which there is attached a centralizer 7 for maintaining the tool 1 centrally arranged inside the riser (not shown). The centralizer 7 has a centrally arranged vertical bore through it.

Fig. 2 shows a cross section view of the annulus access and alignment tool 1 . Inside the casing 5 there is arranged a guiding channel 9. The guiding channel 9 comprises an upper aperture 9a and a lower aperture 9b. Wire-suspended equipment, such as a plug (not shown), can be led through the apertures 9a, 9b when it is to be installed in an annulus bore, or when retrieving it from the annulus bore.

A plug can be set in the annulus bore of the tubing hanger with a running tool (not shown). A jarring tool can be used to force the plug into the bore. The latter can also be done by applying pressure above the plug, from the riser.

Below the upper receiving aperture 9a, the guiding channel 9 has an entrance portion 9c with downwardly increasing diameter. Below the entrance portion 9c, the channel 9 has a middle portion 9d with constant diameter. The middle portion 9d ends in a narrowing portion 9e, which has a funnel shape with a diameter at its lower part which is smaller than its diameter at its upper part. The middle portion 9d is longer than the entrance portion 9c and the narrowing portion 9e. When the annulus access and alignment tool 1 is correctly installed above the tubing hanger 3, the lower part of the narrowing portion 9e is arranged or aligned above the annulus bore of the tubing hanger 3, however with a distance to the tubing hanger 3. The dimensions of the channel are adapted to accommodate the wire-suspended equipment in question, such as a plug running tool.

Between the lower part of the narrowing portion 9e and the lower aperture 9b, the guiding channel 9 comprises an exit portion 9f. The exit portion 9f has a smaller diameter than the middle portion 9d and is offset with respect to the upper receiving aperture 9a as well as with respect to the central axis of the tool 1 itself. Furthermore, the exit portion 9f has a constant diameter and is adapted to align a plug running tool or retrieving tool (not shown) with respect to the annulus bore. In addition, the narrow diameter of the exit portion 9f ensures that the running or retrieving tool will be oriented in parallel with the longitudinal axis of the tool 1 . Also shown in Fig. 1 and Fig. 2 is a lower body 1 1 which is arranged below the casing 5.

Fig. 3 shows the lower body 1 1 of the tool 1 arranged inside, but not locked to, a tubing hanger 3. The tubing hanger 3 has a production bore 13 and an annulus bore 15, typically having diameters of 5" and 2".

At the upper part of Fig. 3, the lower part of the guiding channel exit portion 9f is indicated, the lower end of which constituting the guiding channel lower aperture 9b. The guiding channel 9 is prolonged downwards with a lower body through bore 17. At the lower end of the through bore 17, an annulus bore stinger 19 is connected to the lower body 1 1 . The stinger 19 is provided with seals 20 which make a sealed engagement with the annulus bore 15 of the tubing hanger 3 when the tool 1 is landed. There is also a sealed connection between the stinger 19 and the lower body 1 1 .

In the position shown in Fig. 3, the lower body 1 1 of the tool 1 is not fully landed in the tubing hanger 3. When landed, the annulus bore stinger 19 will extend into the annulus bore 15 of the tubing hanger 3. As mentioned, the annulus bore stinger 19 is provided with seals 20 which provide a sealed connection between the tool 1 and the tubing hanger annulus bore 15.

In the position shown in Fig. 3, the tool 1 has landed on a tubing hanger upper shoulder 21 with an orientation key 23 which is attached to the lower body 1 1 . To make further downward movement of the tool 1 possible, it is rotated until the orientation key 23 is aligned with an orientation slot 25 in the tubing hanger 3. The rotation can be provided by rotation of a drill string (not shown) to which the tool 1 is connected. When the orientation key 23 is aligned with the orientation slot 25, the tool 1 will move further down due to gravity. The tool 1 will then have the correct angle alignment with respect to the tubing hanger 3.

Referring now to Fig. 4, the lower body 1 1 has moved down to fully landed position in the tubing hanger 3. The annulus bore stinger 19 extends into the annulus bore 15 of the tubing hanger 3. Furthermore, a locking split ring 27 is aligned with internal locking profile 29 of the tubing hanger 3, however not engaged. For engagement of the locking split ring 27 with the internal locking profile 29, a locking sleeve 31 is moved downwards. This downwardly movement is provided by shoving the casing 5 of the tool 1 downwards. The casing 5 is operatively connected to the locking sleeve 31 .

The tool 1 is locked to the tubing hanger 3 when the locking sleeve 31 has been forced down and the locking split ring 27 has been forced into engagement with the internal locking profile 29 of the tubing hanger 3. As appears from Fig. 3 and Fig. 4, the locking sleeve 31 actuates the locking split ring 27 in a radial outwards direction by engaging it with an inclined face. This locking function is well known to a man skilled in the art and should need no further description.

Referring again to Fig. 4, a vertical slot 33 is shown in the locking sleeve 31 . A protrusion 35 is attached to the main body 1 1 of the tool, and extends into the vertical slot 33. This combination of slot 33 and protrusion 35 limits the possible movement of the locking sleeve 31 in both vertical directions. Preferably, a plurality of such combinations of slot and protrusion are arranged about the circumference of the lower body 1 1 . Before the locking sleeve 31 is moved down to activate the locking split ring 27, it is held in place by a first set of shear pins (not shown) which extend from the main body 1 1 of the tool 1 and into facing recesses (not shown) in the locking sleeve 31 . The downwardly directed force of the locking sleeve 31 shears off the shear pins. Similarly, when the locking sleeve 31 has been moved down to the locking position, the shear pins of a second set of shear pins snap into mating recesses in the main body 1 1 of the tool 1 . When the locking sleeve 31 is pulled up for unlocking of the locking split ring 27, the shear pins of the second set of shear pins are sheared as well. This is performed by a controlled pull in the workover riser (not shown).

Locking the annulus access and alignment tool 1 to the tubing hanger 3 is a great advantage in bad weather. When the tool 1 is locked to the tubing hanger 3 the workover riser (not shown) can move freely in the vertical direction with respect to the floating installation to which it extends. Without the possibility of locking the tool 1 , keeping a tool as the tool 1 according to the invention in constant place in bad weather is difficult or even impossible. Due to the sealed connection between the stinger 19, comprising seals 20, and the tubing hanger 3, the operator may perform pressure test of an installed plug in the annulus bore 15.

It is now referred to Fig. 5, showing the lower part of the tool 1 locked to the tubing hanger 3. This figure illustrates circulation of fluid through the tool 1 according to the invention, to the annulus bore 15 and back up through the production bore 13. When returning the fluid will flow up again through a fluid exit bore 45 extending vertically through the lower body 1 1 of the tool 1 . From the fluid exit bore 45 it exits into a space between the guiding channel 9 and the casing 5 of the tool 1 . Further it exits the casing 5 through a vent 47 in the casing 5. From there it flows in an annulus space between the casing 5 of the tool 1 and a blow out preventer (BOP) 49. In the BOP 4 is arranged a BOP vent 51 , through which the liquid flows into the sea. A sealed connection between the production bore 13 and the fluid exit bore 45 can advantageously be arranged, as will be understood by a person skilled in the art. Furthermore, as will be appreciated by a person skilled in the art, it would also be possible to circulate fluid in the opposite direction.

The above example description referring to Fig. 1 to Fig. 5 shows the tool 1 according to the invention landed on a tubing hanger 3 with a production bore 13 and an annulus bore 15. The tool 1 can however also be used to provide aligned access to eccentrically arranged bores of other subsea units, such as the annulus bore of a vertical Xmas tree.

Claims

1 . Access and alignment tool (1 ), suitable for providing a wire suspended subsea arrangement, such as a plug running tool, with access and alignment to the annulus bore (15) in a tubing hanger (3) or a Xmas tree having a production bore (13) and an annulus bore (15), said tool (1 ) exhibiting an elongated shape with an inner guiding channel (9), said guiding channel (9) having an upper receiving aperture (9a) and a lower aperture (9b), which lower aperture (9b) is adapted to be arranged directly above and aligned with the annulus bore (15) when the access and alignment tool (1 ) is installed above the annulus bore (15), which access and alignment tool (1 ) is suitable to be run through a monobore riser,

characterized in that

- the access and alignment tool (1 ) is adapted to provide a sealed connection between said guiding channel (9) and the annulus bore (15); and that

- it comprises a fluid exit bore (45) adapted for communicating fluid with said production bore (13).

2. Tool according to claim 1 , characterized in that it comprises a stinger (19) adapted to enter into said annulus bore (15), wherein said stinger (19) is provided with seal (20) adapted to provide a sealed connection between the inner guiding channel (9) of the tool (1 ) and the annulus bore (15).

3. Tool according to any one of the preceding claims, characterized in that it comprises locking means (27) adapted to lock to an internal locking profile (29) of the tubing hanger (3) or Xmas tree.

4. Method of inserting a plug into an annulus bore (15) after having guided the plug through an access and alignment tool (1 ) according to claim 1 , characterized in forcing the plug (43) into the annulus bore (15) by applying pressure above it, through the guiding channel (9) of said access and alignment tool (1 ).