Subsea position control system for elongate articles

Abstract

A method of controlling subsea laying of an elongate article is disclosed and includes guiding the article using a submersible vehicle such as an ROV that carries a guide tool. The guide tool has a sleeve through which the article moves axially during laying, while the vehicle applies cross-axial guide forces to the article via the sleeve. Also disclosed is a guide tool including a sleeve through which the article can move axially during laying, and a grab handle whereby a submersible vehicle may hold the tool using a grabber. Alternatively, the guide tool can be attached to or integrated with the vehicle.

1 - 27 . (canceled) 
     
     
         28 . A guide tool suitable for subsea laying of an elongate article when used by a submersible vehicle, the tool comprising:
 a sleeve through which the article can slide axially during laying; and   a grab handle for a grabber of a submersible vehicle.   
     
     
         29 . The tool of  claim 28 , wherein the sleeve comprises a gate extending along its length. 
     
     
         30 . The tool of  claim 29  further comprising a lock member movable between a locked position and an unlocked position, the lock member being cooperable with lock formations on the sleeve to lock the gate closed when in the locked position and to release the gate for opening when in the unlocked position. 
     
     
         31 . The tool of  claim 30 , wherein the lock member is carried by and movable with respect to the gate. 
     
     
         32 . The tool of  claim 30 , wherein the gate is attached to a body of the sleeve by a hinge and the lock member is mounted to the gate at a location opposed to the hinge. 
     
     
         33 . The tool of  claim 30 , wherein force applied to move the lock member into the lock position also acts to close the gate. 
     
     
         34 . The tool of  claim 30 , wherein the lock member is biased into the unlocked position. 
     
     
         35 . The tool of  claim 30 , wherein the lock member includes a grab point to be grasped by a manipulator claw of the submersible vehicle. 
     
     
         36 . The tool of  claim 30 , wherein the lock mechanism further comprises a latch member cooperable with the lock member to hold the lock member in the locked position. 
     
     
         37 . The tool of  claim 36 , wherein the latch member is biased to engage the lock member in the locked position. 
     
     
         38 . The tool of  claim 36 , wherein an element of the lock member is connected to the latch member for movement along a path, the path defining a latch position at which the latch member engages the lock member to hold the lock member in the locked position. 
     
     
         39 . The tool of  claim 36 , wherein the latch member is movably mounted to the gate. 
     
     
         40 . A submersible vehicle carrying a guide tool suitable for subsea laying of an elongate article, the tool comprising a sleeve through which the article can slide axially during laying; characterized in that the sleeve can be opened to receive the article and can be closed around the article. 
     
     
         41 . The submersible vehicle of  claim 40 , wherein:
 the guide tool comprises a grab handle for a grabber of the submersible vehicle; and   the guide tool is attached to the submersible vehicle via the grab handle.   
     
     
         42 . The submersible vehicle of  claim 40 , wherein the sleeve comprises a gate extending along its length. 
     
     
         43 . The submersible vehicle of  claim 42  further comprising a lock member movable between a locked position and an unlocked position, the lock member being cooperable with lock formations on the sleeve to lock the gate closed when in the locked position and to release the gate for opening when in the unlocked position. 
     
     
         44 . The submersible vehicle of  claim 43 , wherein the lock member is carried by and movable with respect to the gate. 
     
     
         45 . The submersible vehicle of  claim 43 , wherein the gate is attached to a body of the sleeve by a hinge and the lock member is mounted to the gate at a location opposed to the hinge. 
     
     
         46 . The submersible vehicle of  claim 43 , wherein force applied to move the lock member into the lock position also acts to close the gate. 
     
     
         47 . The submersible vehicle of  claim 43 , wherein the lock member is biased into the unlocked position. 
     
     
         48 . The submersible vehicle of  claim 43 , wherein the lock member includes a grab point to be grasped by a manipulator claw of the submersible vehicle. 
     
     
         49 . The submersible vehicle of  claim 43 , wherein the lock mechanism further comprises a latch member cooperable with the lock member to hold the lock member in the locked position. 
     
     
         50 . The submersible vehicle of  claim 49 , wherein the latch member is biased to engage the lock member in the locked position. 
     
     
         51 . The submersible vehicle of  claim 49 , wherein an element of the lock member is connected to the latch member for movement along a path, the path defining a latch position at which the latch member engages the lock member to hold the lock member in the locked position. 
     
     
         52 . The submersible vehicle of  claim 49 , wherein the latch member is movably mounted to the gate. 
     
     
         53 . A method of controlling subsea laying of an elongate article, comprising guiding the article using a submersible vehicle to apply guide forces to the article while the article moves relative to the submersible vehicle during laying, wherein the submersible vehicle carries a guide tool having a sleeve through which the article slides axially during laying while the vehicle applies cross-axial guide forces to the article via the sleeve; characterized in that the method further comprises opening the sleeve to receive the article and then closing the sleeve around the article. 
     
     
         54 . The method of  claim 53 , comprising locking the sleeve closed by using the submersible vehicle to manipulate a lock mechanism on the guide tool. 
     
     
         55 . The method of  claim 53 , comprising varying the orientation of the sleeve with respect to the submersible vehicle to influence or to match the inclination and direction of the article in the region of the sleeve. 
     
     
         56 . The method of  claim 53 , comprising automatically controlling movement of the submersible vehicle along a lay path. 
     
     
         57 . The method of  claim 56 , wherein the submersible vehicle follows a path pre-defined by waypoints. 
     
     
         58 . The method of  claim 56 , wherein movement of the submersible vehicle is coordinated with movement of an installation vessel from which the elongate article is launched. 
     
     
         59 . The method of  claim 58 , wherein the submersible vehicle is set to stay within a specified area relative to the installation vessel. 
     
     
         60 . The method of  claim 58 , wherein the installation vessel is set to stay within a specified area relative to the submersible vehicle. 
     
     
         61 . The method of  claim 53 , wherein the submersible vehicle maintains a preordained water depth during the lay process. 
     
     
         62 . The method of  claim 53 , wherein the submersible vehicle maintains a preordained height above the seabed during the lay process. 
     
     
         63 . A method of controlling subsea laying of an elongate article, the method comprising guiding the article using a submersible vehicle to apply guide forces to the article while the article moves relative to the submersible vehicle during laying; characterized by:
 monitoring the position of the submersible vehicle with respect to an installation vessel from which the elongate article is launched; and   guiding the installation vessel and the submersible vehicle in coordination by guiding the installation vessel in accordance with the position of the submersible vehicle.   
     
     
         64 . The method of  claim 63 , further comprising monitoring and controlling the position of the submersible vehicle with respect to the seabed.