The present invention relates to a hot stab and receptacle assembly. The assembly comprises a hot stab adapted for insertion into a hot stab receptacle and thereby to establish a fluid communication between a fluid line connected to the hot stab and a fluid channel in the receptacle. In particular, the invention relates to such a hotstab that is provided with means to prevent fluid

communication between the hotstab and the surroundings when the hotstab is not inserted into the receptacle. Background

In the subsea field, fluid connection means known as hot stabs are a well known for establishing a fluid connection in a subsea environment. The hot stab is connected to a fluid line and establishes fluid communication with a hot stab receptacle when inserted into the same. US patent publication US4863314 describes such a hot stab comprising bar-shaped stabbing part with a pair of ring-shaped seals extending circumferentially about it. Between the two seals is a fluid port that aligns with a fluid port in the receptacle bore, into which the stabbing part is inserted. The fluid port of the stabbing part communicates with a fluid passage in the stabbing part that further communicates with a fluid line attached to the hot stab. The two ring-shaped seals seal against the bore of the receptacle and fluid communication between the stabbing part and the

receptacle.

Hot stabs are often operated by means of a remotely operated vehicle (ROV). For instance, a surface vessel lowers a fluid line from the surface down towards equipment located on the seabed. At the end of the fluid line a hot stab is connected. Then, at the seabed, the operator may use an ROV to inset the hot stab into a hot stab receptacle associated with the subsea equipment, thereby establishing a fluid communication between the surface vessel and the subsea equipment. The subsea equipment can typically be equipment related to hydrocarbon sea wells and the fluid in the fluid line may typically be hydraulic fluid. When lowering the fluid line with the attached hot stab down into the sea, sea water will enter the fluid port in the hot stab and may even enter into a significant portion of the fluid line. Thus, sea water needs to be purged so that sea water does not enter into the subsea equipment, for instance into hydraulic actuators. This can be done shortly before insertion into the receptacle. Alternatively, it can be done after insertion if the receptacle has a flushing valve. This purging process may need several minutes or even half an hour or more. Saving time is a particular desire not only because efficiency as such is an underlying aim, but in particular also because renting such surface vessels and associated ROV equipment can be expensive.

Thus, the object of the present invention is to provide a hot stab and receptacle assembly that reduces or even removes the need for purging. The invention

According to the invention, there is provided a hot stab and receptacle assembly comprising a hot stab adapted to be connected to a fluid line and to stab into a receiving chamber of a receptacle and thereby provide a fluid communication between the fluid line and a receptacle fluid channel in the receptacle. The hotstab comprises a bar-shaped stabbing part which between a front end and a rear end has a hot stab fluid port. When the hot stab is inserted into the receptacle the hot stab fluid port is in fluid communication with a fluid channel port in the receptacle, which is in fluid communication with said receptacle fluid channel. A sleeve is arranged about the stabbing part and adapted to move axially on the stabbing part in a sliding movement between a position on the stabbing part in which it covers the hot stab fluid port and a position on the stabbing part in which it exposes the hot stab fluid port. According to the present invention the sleeve has an extraction edge which is adapted to abut against a receptacle extraction shoulder of the receptacle when the stabbing part is being pulled in a direction out of the receiving chamber. Thereby a sliding movement of the sleeve is provided from the position where it exposes the hot stab fluid port to the position where it covers the hot stab fluid port. Thus, the entering of ambient liquids into the fluid line can be prevented by sliding the sleeve into the position in which it covers the hot stab fluid port.

The stabbing part can comprises two seals that extend about the circumference of the stabbing part and are arranged at respective axial sides of the hot stab fluid port. The seals are adapted to seal against sealing surfaces of the receiving chamber as well as against the inner face of the sleeve.

Furthermore, the receptacle can comprise a receptacle insertion shoulder against which an insertion edge of the sleeve is adapted to abut when the hot stab is being inserted into the receiving chamber. In this way a sliding movement of the sleeve is provided from the position where it covers the hot stab fluid port to the position where it exposes the hot stab fluid port, when the stabbing part is inserted beyond the position in which the insertion edge abuts the insertion shoulder. With such an embodiment of the invention, one does not need to consider sliding the sleeve, since this will happen automatically when inserting the hot stab into the receptacle.

In addition, the stabbing part can further comprise a recessed portion into which a radially movable protrusion of the sleeve slips when the sleeve is being moved to the position where it covers the hot stab fluid port. In this position the extraction edge of the sleeve fits radially within the receptacle extraction shoulder. This feature ensures that the sleeve is pulled out along with the stabbing part when the hot stab is extracted from the receptacle.

The stabbing part can comprise a pulling edge adapted to abut against the protrusion of the sleeve when the protrusion is in the recessed portion. This abutment forces the sleeve to move along with the stabbing part when the stabbing part is being pulled out of the receiving chamber.

The sleeve can have a front portion and a rear portion, wherein the rear portion comprises axially extending arms on which protrusions are located, and wherein the arms are biased to press the protrusions radially inwards against the stabbing part. The stabbing part can comprise a rear edge against which a part of the sleeve is adapted to abut when the stabbing part is being inserted into the receiving chamber and the insertion edge of the sleeve abuts the receptacle insertion shoulder. The abutment between the rear edge and the sleeve is adapted to halt the insertion movement of the stabbing part in a position where the seals engage sealing surfaces on respective axial sides of the fluid channel port.

The stabbing part can comprise a recess into which a protrusion of the sleeve is adapted to slip when the sleeve is in the position on the stabbing part in which it exposes the hot stab fluid port. The rear edge, as mentioned above, may be located in association with the recess, as will be described in the example embodiment further below. A front edge of the recess and/or the protrusion can exhibit an inclined face providing a radially outwards movement of the protrusion, out of engagement with the recess when the protrusion is being moved axially in the direction towards the front edge. Example of embodiment

Having described various features of the invention in general terms above, a more detailed and non-limiting example of embodiment will be described in the following with reference to the drawings, in which Fig. 1 is a schematic cross section view of a hot stab before insertion;

Fig. 2 is a schematic cross section view of a receptacle;

Fig. 3 is a cross section view of a hot stab and receptacle assembly according to the present invention, wherein the hot stab has been partly inserted into the receptacle;

Fig. 4 is a cross section view corresponding to Fig. 3, however with the hot stab fully inserted;

Fig. 5 is a perspective view of the hot stab in a non-inserted stated;

Fig. 6 is an enlarged cross section view of a part of the hot stab and a part of the receptacle; Fig. 7 is a perspective view of the hot stab and the receptacle, in a non-inserted state; and

Fig. 8 is a cross section perspective view of the hot stab and the receptacle, in a non-inserted state.

Fig. 1 and Fig. 2 show respectively, in schematic cross section views, a hot stab 100 and receptacle 200 of a hot stab and receptacle assembly 1 . The hot stab 100 is adapted to be inserted into receiving chamber 201 of the receptacle 200. In Fig. 3 the hot stab 100 is shown inserted into the receptacle 200.

The hot stab 100 comprises a stabbing part 101 having a front end 101 a and a rear end 101 b. At the rear end 101 b it is connected to a fluid line 103. The fluid line 103 is only partly shown in Fig. 1 , and can for instance be a hydraulic line conducting pressurised hydraulic oil. Within the stabbing part 101 is a fluid- conducting fluid bore 105 which provides fluid communication between the fluid line 103 and two hot stab fluid ports 107. Although one would suffice, in this embodiment there are arranged two hot stab fluid ports 107 which are arranged at the outer face of the stabbing part 101 and are in fluid communication with the fluid bore 105. On each axial side of the hot stab fluid ports 107 there is arranged a seal 109. The seals 109 extend about the circumference of the stabbing part 101 .

In the position shown in Fig. 1 , a sleeve 1 1 1 is in such an axial position on the stabbing part 101 that its inner face makes a sealing contact with the two seals 109. In this position the sleeve 1 1 1 also covers the hot stab fluid ports 107. Thus, the hot stab fluid ports 107 are shut off from communication with the exterior of the hot stab 1 .

Fig. 2 shows the receptacle 200 without the hot stab 100 inserted into the receiving chamber 201 of the receptacle. The receiving end of the receiving chamber 201 (on the right hand side of Fig. 2) has a circular cross section and is dimensioned to accommodate the stabbing part 101 along with the sleeve 1 1 1 of the hot stab 100. Further to the left, the receiving chamber 201 exhibits a receptacle insertion shoulder 203. The receiving chamber 201 further exhibits two inwardly facing sealing surfaces 205. The sealing 205 surfaces are adapted to seal against the two seals 109 of the hot stab 100. Axially between the two sealing surfaces 205 there is arranged a fluid channel port 207. The fluid channel port 207 of the receptacle 200 is in fluid communication with a receptacle fluid channel 209. The receptacle fluid channel 209 is in fluid communication with a piece of subsea equipment, which for instance can be a hydraulically actuated valve (not shown). The fluid channel port 207 extends about the circumference of the receiving chamber 201 , between the two sealing surfaces 205. Thus, angular orientation of the stabbing part 101 of the hot stab 100 about its centre axis is arbitrary in order to achieve fluid communication between the hot stab 100 and the receptacle 200. Shown at the left hand side of Fig. 2, the receptacle 200 exhibits a venting port 21 1 . When inserting the hot stab 100 into the receptacle 200, the venting port 21 1 lets out fluid in the receiving chamber 201 , thereby facilitating the insertion.

The sleeve 1 1 1 is adapted to slide in an axial direction between the axial position shown in Fig. 1 and the axial position shown in Fig. 4. Referring now to Fig. 3 and Fig. 4, when inserting the stabbing part 101 into the receiving chamber 201 of the receptacle 200, an insertion edge 1 13 of the sleeve 1 1 1 abuts against the receptacle shoulder 203. Fig. 4 shows the insertion of the hot stab 100 partly into the receptacle 200. In this position, the insertion edge 1 13 has made contact with the receptacle shoulder 203. This abutment prevents the sleeve 1 1 1 from further insertion. The stabbing part 101 of the hot stab 100 is however inserted further, during which insertion the sleeve 1 1 1 slides on the stabbing part 101 . The sleeve 1 1 1 is thus slid backwards on the stabbing part 101 when the stabbing part 101 is inserted further. During this insertion process, the two seals 109 and the hot stab fluid port 107 slide out of the position within the sleeve 1 1 1 , and into a narrow portion of the receiving chamber 201 . The insertion movement stops in a position where the hot stab fluid port 107 is aligned with the fluid channel port 207 of the receptacle, and the two seals 109 are in engagement with the facing sealing surfaces 205. This position is shown in Fig. 4. As explained above, the insertion of the sleeve 1 1 1 is halted by abutment against the receptacle shoulder 203. At a rear portion 1 1 1 b of the sleeve 1 1 1 , it comprises a radially inwardly directed protrusion 1 15 which slips into a recess 1 17 of the stabbing part 101 of the hot stab 100, when the latter is inserted a further distance than the sleeve 1 1 1 . When the protrusion 1 15 slips into the recess 1 17, the insertion movement of the stabbing part 101 is halted in the correct inserted position, as shown in Fig. 4 (see also the enlarged view of Fig. 6). The recess 1 17 extends about the circumference of the stabbing part 101 . As appears perhaps most clearly from Fig. 5 and Fig. 7, the rear portion 1 1 1 b of the sleeve is divided into a plurality of arms 1 19 extending axially rearwards from a front portion 1 1 1 a of the sleeve 1 1 1 . The arms 1 19 making the rear portion 1 1 1 b of the sleeve 1 1 1 , including the protrusions 1 15, are able to pivot in a radial direction. Fig. 5 shows the hot stab 100 without the receptacle. In Fig. 5 the sleeve 1 1 1 is in the non-inserted position, covering the seals 109 and the hot stab fluid port 107.

Fig. 6 is an enlarged cross section view of a rear end of an arm 1 19 with the protrusion 1 15 arranged within the recess 1 17. The recess 1 17 has a rear edge 1 17a which prevents the further insertion of the stabbing part 101 , as explained above. The rear edge 1 17a has such a radial extension and such an angle with respect to the direction of insertion, that it completely halts the inward movement of the stabbing part 101 . The description above explains how the sleeve 1 1 1 is moved backwards on the stabbing part 101 when the hot stab 100 is inserted into the receptacle 200, and how the stabbing part 101 is halted in the correct position by the protrusions 1 15 slipping into the recess 1 17. In the following, the reverse process will be described, namely how the sleeve 1 1 1 is slid in the opposite direction on the stabbing part 101 when the latter is pulled out of the receiving chamber 201 in an extraction direction.

It is again referred to Fig. 6, showing an enlarged cross section view of the rear part of an arm 1 19 having its protrusion 1 15 in engagement with the recess 1 17 of the stabbing part 101 . On one side of the recess 1 17, opposite of the rear edge 1 17a, there is a front edge 1 17b. The front edge 1 17b has such a radial extension and an inclination which makes the protrusion 1 15 of the arms 1 19 slip out of engagement with the recess 1 17 when the sleeve 1 1 1 is pushed in a rearwards direction, i.e. the direction opposite of the insertion direction. That is, the sleeve 1 1 1 is pushed towards the left in Fig. 6, with respect to the stabbing part 101 , which is pulled out towards the right. At the axial position of the protrusions 1 15, there is some radial space between the arm 1 19 and the inwardly facing face of the receiving chamber 201 . Furthermore, an extraction edge 121 at the rear portion 1 1 1 b of the sleeve 1 1 1 is adapted to abut against a receptacle extraction shoulder 213 of the receptacle. When pulling the hot stab 100 in the direction out of engagement with the receptacle 200 (towards the right in Fig. 6), the extraction edge 121 will abut against the receptacle extraction shoulder 213. This abutment makes the sleeve 1 1 1 remain in its axial position while the stabbing part 101 is pulled outwards (towards the right in Fig. 3 and Fig. 6). Due to the inclined faces of the protrusion 1 15 and the recess 1 17, the protrusion will move out of engagement with the recess 1 17, thereby letting the stabbing part 101 move, as explained above. Then, when the stabbing part 101 has moved so far that the sleeve 1 1 1 is in the position in which it covers the two seals 109 and the hot stab fluid port 107, the protrusions 1 15 of the arms 1 19 are situated in a recessed portion 123 of the stabbing part 101 . The recessed portion 123 is sufficiently deep to let the extraction edge 121 of the sleeve 1 1 1 move past the receptacle extraction shoulder 213, radially outside of it. When in the recessed portion 123, the protrusions 1 15 abut against a pulling edge 125, so that the sleeve is pulled out along with the stabbing part 101 , in the position in which it covers the seals 109 and the hot stab fluid port 107. This is the position shown in Fig. 1 and Fig. 5.

The arms 1 19 constituting the rear portion 1 1 1 b of the sleeve 1 1 1 have a flexible portion 1 19a at the mid part of the arms 1 19. The arms 1 19 are inwardly biased so as to take a position radially within the receptacle extraction edge 213, provided there is sufficient space within their protrusions 1 15. In the position shown in Fig. 1 , the protrusions 1 15 are arranged at the recessed portion 123. In this position the sleeve 1 1 1 , and its rear portion 1 1 1 b, is arranged radially within the receptacle extraction edge 213.

Fig. 7 is a perspective view of the hot stab 100 and the receptacle 200 before insertion or after extraction. One can recognise that the sleeve 1 1 1 is in the non- inserted position in which it covers the seals 109 and the hot stab fluid port 107. Thus the recess 1 17 is visible.

Fig. 8 is a perspective cross section view of the hot stab and receptacle assembly 1 in the non-inserted position.

List of reference numbers

1 hot stab and receptacle assembly

100 hot stab

101 stabbing part

101a front end (of stabbing part)

101b rear end (of stabbing part)

103 fluid line

105 fluid bore

107 hot stab fluid port

09 seal

111 sleeve

111a front portion (of sleeve)

111b rear portion (of sleeve)

113 insertion edge (on sleeve)

115 protrusion

117 recess

117a rear edge

117b front edge

119 arm

121 extraction edge (on sleeve)

123 recessed portion

125 pulling edge

200 receptacle

201 receiving chamber

203 receptacle insertion shoulder

205 sealing surface

207 fluid channel port (of receptacle)

209 receptacle fluid channel

211 venting port

213 receptacle extraction shoulder