Abstract:
A male connector ( 3 ) to be inserted into a female connector ( 5 ). The male connector defines a conduit and comprises a locking means ( 39 ) operable to engage the female connector to thereby lock the male connector relative to the female connector. The male connector also comprises a release means ( 17 ) for unlocking the male connector to permit the male connector to be separated from the female connector. The release means is accessible from within the conduit. There may be a release tool ( 50 ) operable to disengage the male connector from the female connector and retain the male connector after the male connector has been disengaged from the female connector.

Description:
TECHNICAL FIELD OF THE INVENTION 
       [0001]    The present invention relates to an apparatus and method for disconnecting male and female connectors such as those used in oil pipeline connections. 
       BACKGROUND TO THE INVENTION 
       [0002]    Risers are used in subsea applications to provide a conduit for oil to be extracted from under the sea bed to floating production storage and offloading vessels (FPSO) or similar. The risers comprise a number of pipe sections that are joined together so that the oil can be conveyed safely to the surface of deep water. Due to movement of the vessel on the surface of the water, the risers are often subjected to external forces that cause the risers to flex and kink thereby resulting in damage to the risers. To reduce the likelihood of damage, bend stiffeners comprising a polyurethane conical shaped moulding are used to limit bending of the risers and protect the riser minimum bend radius. 
         [0003]    Bend stiffeners are typically coupled to a FPSO vessel using a male and female connector. One of the connectors is usually attached to the vessel and the other connector is usually attached to the bend stiffener. The bend stiffener and corresponding connector are coupled to the connector on the vessel to lock the two together and hold the bend stiffener firmly in place. The riser can then be safely attached to the vessel through the bend stiffener so that oil can be extracted from the oil field in question. 
         [0004]    When it is desired to separate the riser from the vessel, the male and female connectors may typically be urged apart using hydraulic rams, release or riser clamps. Such methods of separation can be prone to failure and require physical intervention by divers which is undesirable especially in potentially hazardous conditions. 
         [0005]    It is an object of the present invention to provide a more convenient and reliable way to separate male and female connectors. 
       SUMMARY OF THE INVENTION 
       [0006]    According to a first aspect of the present invention, there is provided a male connector intended to be inserted into a female connector, the male connector defining a conduit and comprising a locking means operable to engage the female connector to thereby lock the male connector relative to the female connector and a release means for unlocking the male connector to permit the male connector to be separated from the female connector, characterised in that the release means is accessible from within the conduit. 
         [0007]    Advantageously, by making the release means accessible from inside the conduit it is possible to easily disengage the release means using a separate tool that can also be used to secure the male connector in the same operation so that the male connector can be safely and controllably removed from the female connector. 
         [0008]    The locking means may have operative and inoperative positions in relation to the female connector and the release means may be operable between a permissive position in which the locking means can move between operative and inoperative positions and a preventative position in which the locking means is prevented from moving between operative and inoperative positions. 
         [0009]    The release means may be operable from within the conduit by engaging the release means and urging the release means between permissive and preventative positions. 
         [0010]    According to a second aspect of the present invention, there is provided a connector assembly comprising a male connector and a female connector that connectively define a conduit, a locking means arranged to lock the male connector relative to the female connector and a release means operable to unlock the male connector from the female connector, characterised in that the release means is accessible from within the conduit. 
         [0011]    The locking means may be part of the male connector or the female connector. The release means may be part of the male connector or the female connector. 
         [0012]    According to a third aspect of the present invention there is provided a release tool for use with a connector or connector assembly according to the first or second embodiments comprising a body arranged to be inserted into the conduit and an engagement means arranged to engage the release means to unlock the male connector relative to the female connector. 
         [0013]    The engagement means of the release tool may be arranged, in use, to engage the male connector and retain the male connector relative to the release tool after the male connector is unlocked from the female connector. 
         [0014]    The release tool may further comprise a limiter that limits the distance the release tool may extend into the conduit so that when the release tool extends the fully permitted distance into the conduit, the engagement means is positioned to engage the release means. The limiter may comprise a flange that is intended to abut a part of the male or female connector. The engagement means may comprise one or more balls for gripping the release means. 
         [0015]    The release tool may further comprise one or more tapered grooves and the or each ball may be seated in a corresponding tapered groove and limited to movement along the groove by a sleeve that extends over the or each groove, the sleeve comprising an aperture for each ball so that the or each ball can extend at least partially through the sleeve. The or each groove may be shaped such that when the ball is in one position in the groove it extends at least partially through the aperture of the sleeve and when in another position the ball is substantially inside the sleeve. The sleeve may be biased toward a position in which the or each ball is urged at least partially through the or each aperture. 
         [0016]    According to a fourth aspect of the present invention, there is provided a method of disconnecting a male connector from a female connector comprising the steps of: 
         [0017]    providing a male connector defining a conduit and having a release means that when activated permits the male connector to be separated from the female connector, the release means being accessible from the conduit; and 
         [0018]    inserting a release tool into the conduit to activate the release means and permit the male connector to be separated from the female connector. 
         [0019]    The method may further comprise the step of coupling the release tool with the male connector so that the release tool can be used to remove the male connector from the female connector. 
     
    
     
       DETAILED DESCRIPTION OF THE INVENTION 
         [0020]    In order that the invention may be more clearly understood an embodiment thereof will now be described, by way of example only, with reference to the accompanying drawings, of which: 
           [0021]      FIG. 1  shows cross section view of a male connector according to the present invention when locked relative to a female connector and waiting to receive a release tool; 
           [0022]      FIG. 2  shows a cross section view of the male and female connectors of  FIG. 1  when the release tool is fully inserted into the male connector; 
           [0023]      FIG. 3  shows an enlarged cross section view of a part of the male and female connectors and the release tool shown in  FIG. 2 ; 
           [0024]      FIG. 4  shows an enlarged view of the male and female connectors shown in  FIG. 1  when the release tool is pulled out from the male connector; 
           [0025]      FIG. 5  shows the male connector and release tool of  FIG. 1  when connected being removed from the female connector; 
           [0026]      FIG. 6  shows a perspective view of the male inserted in the female connector shown in  FIG. 1  with part cut away; 
           [0027]      FIG. 7 a    shows a perspective cross section view of part of the male connector shown in  FIG. 1  when the male connector is in a locked configuration; 
           [0028]      FIG. 7 b    shows a perspective cross section view of part of the male connector shown in  FIG. 1  when the male connector is in an unlocked configuration; 
           [0029]      FIG. 8  shows a perspective view of the female connector shown in  FIG. 1  with part cut away; and 
           [0030]      FIG. 9  shows a cross section view of a side of the female connector shown in  FIG. 1 . 
       
    
    
       [0031]    Referring to the drawings there is shown a connection assembly  1  comprising a male connector  3  and a female connector  5 . The female  5  connector defines a tapered bore  6  into which the male connector  3  may be inserted and further comprises a flared guide cone  7  at one opening to help guide the male connector  3  into the bore. The male connector  3  also defines a bore  8  so that when the male connector  3  and female connector  5  are coupled together, they both define a conduit through which a section of riser may extend. 
         [0032]    The male connector  3  comprises a substantially cylindrical steel body  9  having a flange  11  at one end to facilitate attachment of the male connector  3  to a bend stiffener. A nose cone  13  is provided at the other end of the male connector  3  to protect the male connector  3  from damage upon insertion into the female connector  5  and also help to guide the male connector  3  into the female connector  5 . A plurality of spring tubes  15  extend axially from an end of the nose cone  13  toward the flange end of the male connector. The spring tubes  15  serve as a support along which a substantially cylindrical hollow steel locking sleeve  17  may travel. A plurality of bores equal to the number of spring tubes  15  is formed in one end of the sleeve  17  to enable the sleeve to slide along the spring tubes axially with respect to the male body  9 . A coil spring is retained within each bore and arranged to bias the sleeve  17  axially away from the nose cone  13 . 
         [0033]    A pair of diametrically opposed grooves  19  is formed in the sleeve  17 . Each groove  19  comprises a substantially cylindrical depression  21  formed in the inner surface of the sleeve  17 , a shallower channel  23  that extends from the cylindrical depression  21  along the inner surface of the sleeve  17  to the nose cone end of the sleeve  17  and a cut-out  25  that extends through the sleeve  17  from one side to the other and from the centre of the depression  21  along the centre of the channel  23  to the end of the sleeve  17 . 
         [0034]    Each groove  19  is arranged to interact with a corresponding latch pin  27  that extends through the sleeve  17  from one side to the other via the cut-out  25  and that is spring loaded to bias the latch pins  27  outwardly from the sleeve  17 . The latch pin  27  comprises a substantially cylindrical body  29  having a substantially flat, circular foot  31  that extends radially from one end of the body and that has a larger diameter than the body  29 . A cylindrical head section  33  is provided at the other end of the body  29 . The head section  33  also has a larger diameter than the body  29  and is shaped to have a curved top to permit smooth contact with the walls of the female connector  5 . 
         [0035]    The depression  21  on the inside of the sleeve  17  is dimensioned to receive at least part of the foot  31  of the latch pin  27  so that when the foot  31  is received into the depression  21 , the latch pin  27  and the sleeve  17  cannot move axially relative to one another. The channel  23  is dimensioned to have a width greater than the diameter of the platform  31  whilst the cut-out  25  is dimensioned to have a width greater than the body  29  of the latch  27 . The cut-out  25  and channel  23  therefore permit the sleeve  17  to move along a controlled axial path along the body  9  of the male connector  3 , guided by the latch pin  27 . 
         [0036]    Two diametrically opposed apertures  35  are formed through the body  9  of the male connector  3  to permit the latch pin  27  to extend through the body  9 . Each aperture  35  comprises two distinct sections, a first section arranged on the sleeve side of the aperture which has a diameter smaller than the head  33  of the latch pin  27  but larger than the body  29  of the latch pin  27  and a second section extending toward the external side of the body  9  having a diameter larger than the head  33  of the latch pin  27 . The interface between the first section and second section creates a stepped edge against which the latch pin head  33  may abut to limit the extent to which the latch pin  27  can be urged into the bore  8  of the male connector  3 . The apertures  35  restrict movement of the latch pins  27  to radial movement only so that when the sleeve  17  moves axially along the body  9 , the latch pins  27  do not move with the sleeve  17 . 
         [0037]    The body  9  of the male connector  3  further comprises a plurality of ball apertures  37  which extend through the body  9  and which are circumferentially spaced around the body  9  along the same plane as the latch pin apertures  35 . Each ball aperture  37  is shaped to receive a spherical locking ball  39 . The diameter of each ball aperture  37  reduces toward the external side of the body  9  to less than the diameter of a corresponding locking ball  39  so as to limit the extent to which a locking ball  39  can project from the aperture  37  and to prevent the locking balls  39  from falling out of the apertures  37 . The locking balls  39  are retained in the apertures  37  on the other side of the body  9  by the sleeve  17  which always extends across the apertures  37 . 
         [0038]    The body facing side of the sleeve  17  comprises a plurality of substantially hemi-spherical grooves  41  equivalent in number to the number of ball apertures  37  and hence balls  39  that extend through the body  9 . The ball grooves  41  are arranged such that, when the sleeve  17  is positioned toward the nose cone  13 , the ball grooves  41  are aligned with the ball apertures  37  so that the locking balls  39  can move into the ball grooves  41 . Thus, the locking balls  39  have two operative positions, a first position in which the locking balls  39  are urged out from apertures  37  toward the external side of the body  9  by the outer surface of the sleeve (as shown in  FIG. 7 a   ) and a second position in which the locking balls  39  can move into the ball grooves  41  (as shown in  FIG. 4 ) from the ball apertures  37 . 
         [0039]    The female connector  5  further comprises a circumferential groove  43  that extends around the internal surface of the connector  5 . The groove or ring  43  is positioned such that when the male connector  3  is fully inserted into the female connector  5 , the ring  43  lies adjacent the ball apertures  37  of the male connector  3 . In this position, the balls  39  may be urged outwardly from the apertures  37  into the ring  43  to help lock the male connector  3  relative to the female connector  5 . A pair of tapered edges  45 ,  47  is positioned either side of the ring  43  to provide abutments for corresponding tapered edges formed on the body  9  of the male connector. The corresponding tapered edges help to correctly position the ring  43  relative to the ball apertures  37  when the tapered edges of the respective connectors  3 ,  5  are brought into contact. 
         [0040]    A connector release tool  50  is also shown. The release tool  50  is dimensioned to fit within the bore  8  of the male connector  3  and is attachable to a work wire that facilitates insertion of the riser and release tool through the male connector  3 . The release tool  50  comprises a substantially cylindrical body  52  having a plurality of tapered grooves  54  formed at spaced apart intervals around the outer surface of the extreme end of the body  52 . A spring loaded ball cage sleeve  56  is arranged around the outside of the body  52  and biased in an axial direction toward the end of the body  52  at which the tapered grooves  54  are formed. The ball cage sleeve  56  is movable between first and second positions along the body  52 . A plurality of substantially circular apertures  58  equivalent to the number of tapered grooves  54  are formed through the ball cage  56  and arranged to lie adjacent the grooves  54  when the ball cage is positioned around the body in both the first and second positions and at every position there between. 
         [0041]    A gripping ball  60  is arranged in each groove  54  between the body  52  and the ball cage aperture  58  thereby restricting movement of the gripping balls  60  to the tapered grooves  54 . The tapering of the grooves  54  is such that when the ball cage sleeve  56  is in the biased, locked position as shown in  FIG. 3 , the gripping balls are urged up the tapered grooves by the ball cage apertures  58  so that the gripping balls  60  project from the ball cage apertures  58 . Each ball cage aperture  58  is constricted toward the outside of the sleeve  56  so as to prevent the gripping balls from falling out from the grooves  54 . When the sleeve  56  is pulled against the action of the springs and moved back from the end of the tool  50 , the gripping balls are urged toward the deeper end of the grooves  54  so that the balls no longer project from the outer surface of the sleeve  56 . 
         [0042]    A ball cage flange  62  or stop is positioned around the outside of the body of the tool  50  between the ball cage sleeve  56  and the point of attachment to the work wire. The ball cage flange  62  is arranged to abut the nose cone  13  of the male connector upon insertion of the tool  50  into the male connector  3  and positioned such that when the ball cage flange  62  abuts the nose cone  13 , the tapered grooves and gripping balls lie adjacent the release sleeve  17  of the male connector  3 . 
         [0043]    In use, a bend stiffener is fixed to the flange  11  of the male connector  3  and the corresponding female connector  5  is fixed to an oil drilling platform or vessel. A work wire is attached to the male connector  3  to enable the male connector  3  to be pulled inside the female connector  5 . Before insertion of the male connector  3  into the female connector  5 , the locking sleeve  17  is urged against the spring loading toward the nose cone  13  until the latch pins  27  are centred over the corresponding depression  21 . The spring loading on the latch pins  27  cause them to move radially outwardly until the latch pin feet  31  sit within the depressions, thereby fixing the sleeve  17  relative to the male body  9 . In this position, the latch pin heads  33  project outside of the body  9  and the locking balls  39  are free to sit within the ball grooves  41 . 
         [0044]    Once the sleeve  17  has been loaded, the male connector  3  is pulled inside the female connector  5  by the work wire. As insertion of the male connector  3  progresses, the internal tapered sides of the female connector  5  begin to squeeze the latch pins  27  in toward the bore of the male connector  3  until the latch pin feet  31  are urged out from the depressions  21 . At this point, the spring loading on the sleeve  17  urges the sleeve  17  away from the nose cone  13 . Movement of the sleeve  17  drives the locking balls  39  out from the ball grooves  41  and further out from the ball apertures  37  so that the locking balls  39  project from the male body  9 . The tapering of the female connector  5  is such that the latch pins  27  and, hence, sleeve  17  are activated when the balls  39  are positioned adjacent the retaining ring  43  on the inner wall of the female connector  5 . The balls  39  may therefore project from the body  9  into the ring  43  and be held in place by the forces exerted on the locking balls  39  by the outer side of the sleeve  17  and the walls of the retaining ring  43 . When in this position, the male connector  3  is locked relative to the female connector  5  as shown clearly in  FIG. 3 . 
         [0045]    When it is desired to unlock the male connector  3  from the female connector  5 , the release tool  50  is attached to the work wire and any fitting attached to the riser and inserted into the bore  8  of the male connector  3 . As the release tool  50  is urged inside the male connector, the ball cage sleeve  56  is urged back toward the ball cage flange  62  by the walls of the nose cone  13 . Movement of the ball cage sleeve  56  toward the flange  62  urges the gripping balls  60  back down the tapered sides of the gripping ball grooves  54  until the balls lie within the walls of the ball cage sleeve  56 . Thus, the release tool  50  can be inserted into the male connector  3  without interference from the gripping balls  60 . 
         [0046]    The release tool  50  is further inserted into the male connector  3  until the stop  62  abuts the face of the male connector nose cone  13 . A reduction in load on the work wire is then seen which indicates the release tool  50  is fully inserted inside the male connector  3  and the tapered grooves  54  and locking balls  60  are lined up with the locking sleeve  17 . In this position, the nose cone  13  no longer acts on the ball cage sleeve  56  and the spring loading urges the ball cage sleeve  56  back toward the end of the release tool  50 . Movement of the ball cage sleeve  56  toward the end of the release tool  50  urges the gripping balls  60  up the tapered grooves  54  until the gripping balls  60  project from the sleeve  56  and engage the internal wall of the locking sleeve  17 . Once the gripping balls  60  engage the locking sleeve  17 , the release tool  50  is pulled back out from the male connector  3 . The friction between the locking sleeve  17  and gripping balls  60  cause the gripping balls  60  to be urged further toward the end of the release tool  50  thereby increasing the force with which the gripping balls  60  engage the locking sleeve  17 . The release tool  50  therefore pulls the locking sleeve  17  toward the nose cone  13  against the spring loading of the locking sleeve  17  until the ball grooves  41  are adjacent the locking balls  39  and the latch pin feet  31  are centred over the depressions  21 . In this position, the locking balls  39  are free to move into the ball grooves  41  and the male connector  3  is therefore unlocked from the female connector. 
         [0047]    Since the male and female connector assembly is intended in use to be substantially vertically oriented, the male connector and attached bend stiffener are pulled down against the action of the gripping balls  60  by gravity. Consequently, the release tool  50  and male connector  3  remain coupled together even after the male connector  3  is unlatched from the female connector  5 . The coupled release tool  50  and male connector  3  are then lowered down out from the female connector  5  (as shown in  FIG. 5 ) and recovered. As the male connector is removed from the female connector, the latch pins no longer abut the inner surface of the female connector and are urged radially outwardly by their spring loading until the feet  31  are seated within the depressions  21 . 
         [0048]    The above embodiment is described by way of example only. Many variations are possible without departing from the scope of the invention as defined in the appended claims.