Drilling vessel

Abstract

A drilling vessel includes a drilling tower and a tubular string support structure for supporting a tubular string in the firing line of the drilling tower. The tubular string support structure has two parallel rails and two carts supported by those rails. Both carts have a hanger body with a central passage for supporting a tubular, and each cart can be moved between a central support position for supporting a tubular in the firing line, and a secondary position adjacent the central support position. When both carts are located in their secondary position, the carts are located on opposite sides of the firing line, such that between the carts there is a passage for passing through large objects along the firing line.

1 . A drilling vessel comprising:
 a drilling tower having a firing line, along which a tubular string is passed into the sea during drilling activities, the firing line extending in a vertical direction; and   a tubular string support structure, the support structure comprising:
 a cart, the cart having a hanger body that defines a vertical passage adapted to receive a tubular string supported in the firing line, and which hanger body defines a lateral passage, in communication with said vertical passage, allowing to place the tubular string in and remove the tubular string from said vertical passage; 
 a bearing support, the bearing support defining an opening concentric with the firing line; and 
 two parallel rails, which rails are provided to support the cart such that it can be moved between a central support position, on the bearing support with the firing line passing through the vertical passage, and a secondary position on the two parallel rails with the firing line passing outside the vertical passage, 
 wherein the bearing support enables rotating the cart when in the central support position about a vertical axis of the vertical passage of the cart. 
   
     
     
         2 . The drilling vessel according to  claim 1 , wherein the cart is adapted for supporting tools as well as tubulars, and the cart thus provides a movable platform for bringing tools into and out of the firing line, and positioning these tools relative to the firing line by rotating them about the firing line, and provides a removable support for tubulars located in the firing line, which in combination with the bearing support enables rotating a tubular or tubular string in the firing line. 
     
     
         3 . The drilling vessel according to  claim 1 , wherein the cart is provided in a recess in a deck, which recess forms an elongated opening in the deck, and
 wherein the cart is supported in the recess in the deck and a top side of the cart is flush with a top surface of the deck.   
     
     
         4 . The drilling vessel according to  claim 1 , wherein the cart is provided in a recess in a deck, which recess forms an elongated opening in the deck, and
 wherein the cart is supported in the recess in the deck and a top side of the cart is located below a top surface of the deck.   
     
     
         5 . The drilling vessel according to  claim 3 , wherein the cart is provided with a deck surface, level with the deck surface of the deck in which the elongated opening is provided, such that the cart forms a slideable deck section. 
     
     
         6 . The drilling vessel according to  claim 1 , wherein the drilling vessel comprises a drilling deck, which drilling deck has a drilling deck top surface, and wherein the tubular string support structure is recessed in the drilling deck such that it supports the cart within the drilling deck, below the drilling deck top surface, and the cart is supported by the rails such that a top side of the cart is located below the top surface of the deck in which the elongate opening is provided. 
     
     
         7 . The drilling vessel according to  claim 1 , wherein the bearing support and the cart are provided with couple devices for coupling the cart, when located in the central support position, with the bearing support, and wherein the bearing support is provided with one or more drives for rotating the bearing support and a cart that is coupled therewith. 
     
     
         8 . The drilling vessel according to  claim 1 , wherein the vessel further comprises a cart transport system, configured for moving the at least one cart along the two parallel rails between the support position and the secondary position. 
     
     
         9 . The drilling vessel according to  claim 8 , wherein the cart transport system comprises one or more transport devices for moving the cart between the secondary position and the central support position. 
     
     
         10 . The drilling vessel according to  claim 8 , wherein the transport devices comprise hydraulic cylinders. 
     
     
         11 . The drilling vessel according to  claim 8 , wherein the transport devices comprise a looped chain or wire. 
     
     
         12 . The drilling vessel according to  claim 1 , wherein the hanger body further defines a lateral passage, in communication with said vertical passage, allowing to place the tubular string in and remove the tubular string from said vertical passage. 
     
     
         13 . The drilling vessel according to  claim 12 , wherein the cart is provided with a closing device configured for closing the lateral passage, which closing device is a door that can block the lateral passage and is designed to provide the hanger body with a ring shaped vertical passage when the lateral passage is closed. 
     
     
         14 . The drilling vessel according to  claim 1 , wherein the hanger body of the cart, is provided with multiple actuable support devices, which support devices can be moved between an active extended position, in which they extend in the vertical passage of the hanger body for supporting a tubular, and a retracted passive position, in which they allow for passing a tubular through the vertical passage of the hanger body in a vertical direction. 
     
     
         15 . The drilling vessel according to  claim 14 , wherein the support devices can be extended into a range of active positions, such that the active position of the support devices can be adapted to fit the diameter of a tubular in the vertical passage, and the hanger body can thus be used with a range of tubulars. 
     
     
         16 . The drilling vessel according to  claim 1 , wherein the tubular string support structure further comprises a frame, the frame connecting at least the two parallel rails such that the tubular string support can be provided as a module for retrofitting in existing drilling vessels to provide a drilling vessel according to the invention. 
     
     
         17 . The drilling vessel according to  claim 1 , wherein the cart is a first cart, and wherein a second cart is provided, such that there are two carts, each cart having a hanger body, wherein each hanger body defines a vertical passage adapted to receive a tubular string supported in the firing line,
 wherein the carts are each supported by the parallel rails such that each cart can be moved between a central support position, above an elongated opening with the firing line passing through the vertical passage, and a secondary position above an elongated opening with the firing line passing outside the vertical passage, and   wherein, when both carts are located in their secondary position, the carts are located on opposite sides of the firing line, such that between the carts there is a passage for passing through objects along the firing line.   
     
     
         18 . The drilling vessel according to  claim 17 , wherein each hanger body defines a lateral passage, in communication with said vertical passage, allowing to place the tubular string in and remove the tubular string from said vertical passage. 
     
     
         19 . A method for assembling and lowering a tubular string comprising tubulars, using a drilling vessel according to  claim 1 , the method comprising:
 supporting a tubular in the firing line using a hoist system of the drilling tower;   moving the cart into the central support position, thus moving the tubular string, supported by the hoist system of the drilling tower, through a lateral passage of the hanger body of the cart;   clamping the tubular in the firing line using the clamping device of the cart, and supporting that tubular in the firing line;   uncoupling the tubular string from the hoist system of the drilling tower;   attaching a tubular to the tubular supported by the cart to form a tubular string;   coupling the tubular string to the hoist system of the drilling tower;   releasing the tubular string with the clamping device of the cart;   lowering the tubular string using the hoist system of the drilling tower;   engaging the upper end of the tubular string with the clamping device of the cart and supporting the tubular string in the firing line; and   uncoupling the tubular string form the hoist system of the drilling tower.   
     
     
         20 . The method according to  claim 19 , further comprising providing a cart having a clamping device for engaging the tubulars.