Drilling vessel

Abstract

The invention relates to a drilling vessel comprising 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.

The invention claimed is: 
     
       1. A drilling vessel comprising:
 a hull; 
 a moonpool; 
 a deck, located over the moonpool, the deck having a top surface and a recess, wherein the recess forms an elongated opening in the deck of the vessel, extends in a downward direction from the top surface of the deck, and provides access to the moonpool below the deck; 
 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 substantially vertical direction, wherein the drilling tower extends in an upward direction from the top surface of the deck; and 
 a tubular string support structure which support structure is provided above the moonpool in the recess in the deck, the support structure comprising:
 two parallel rails provided in the recess on opposite sides of the elongated opening, above the moonpool and below the top surface of the deck, wherein the firing line passes through said elongated opening between the rails; and 
 at least one cart, each cart having a hanger body that defines a vertical passage adapted to receive a tubular string supported in the firing line, 
 wherein each cart is supported in the recess, above the moonpool and below the top surface of the deck by the parallel rails such that each cart can be moved between a central support position, above the elongated opening with the firing line passing through the vertical passage, and a secondary position with the firing line passing outside the vertical passage, and 
 a cart transport system, configured for moving the at least one cart in the recess in the deck along the two parallel rails between the support position and the secondary position. 
 
 
     
     
       2. The drilling vessel according to  claim 1 ,
 wherein each cart is provided with a deck surface, such that each cart forms a slideable deck section. 
 
     
     
       3. The drilling vessel according to  claim 1 ,
 wherein the deck covers the cart when in the secondary position. 
 
     
     
       4. The drilling vessel according to  claim 1 , wherein the cart transport system comprises one or more transport devices for moving the cart between the secondary position and the central support position, and
 wherein the transport devices include one of a hydraulic cylinder or a looped chain or wire. 
 
     
     
       5. The drilling vessel according to  claim 1 , wherein the cart transport system is provided with transport devices located on opposite sides of the elongated opening, such that the cart is moved by at least two transport devices when being transported between the central support position and its secondary position. 
     
     
       6. The drilling vessel according to  claim 1 , wherein the cart transport system further comprises:
 transport devices, wherein each transport devices comprises a chain or a wire, the chains or wires extending on opposite sides of the elongated opening and substantially parallel to the rails of the tubular string support system, and 
 at least one drive for pulling the chains or wires along the rails, 
 wherein the cart is provided with a couple device for coupling the cart with the chains or wires of the transport devices of the transport system. 
 
     
     
       7. The drilling vessel according to  claim 1 , wherein the cart transport system further comprises:
 transport devices, wherein each transport device each comprises a cylinder, the cylinders extend on opposite sides of the elongated opening and extend in a direction substantially parallel to the rails of the tubular string support system, and 
 wherein each cylinder is coupled with one end to the cart and with an opposite end to a frame of the tubular string support structure. 
 
     
     
       8. 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. 
     
     
       9. The drilling vessel according to  claim 8 , wherein the cart is provided with a closing device configured to close the lateral passage,
 wherein the closing device is a moveable door that is configured to move over the lateral passage to close the lateral passage and provides the hanger body with a ring shaped vertical passage when the lateral passage is closed. 
 
     
     
       10. The drilling vessel according to  claim 8 , wherein the hanger body is provided with multiple support devices, and
 wherein the support devices can be moved between active extended positions, 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 and/or into and out of the vertical passage via the lateral passage. 
 
     
     
       11. The drilling vessel according to  claim 10 , wherein the active extended positions are a range of positions for accommodating tubulars with varying diameters. 
     
     
       12. The drilling vessel according to  claim 1 , wherein the at least one cart is provided with three or more clamping blocks, the clamping blocks are provided along the circumference of the vertical passage at even intervals such that they can engage a tubular string extending through said vertical passage, and
 wherein the clamping blocks can be moved in a radial direction with respect to a central axis of the vertical passage, such that tubular strings of different diameters can be engaged with said clamping blocks. 
 
     
     
       13. The drilling vessel according to  claim 12 , wherein the at least one cart is provided with a vertical guide for each clamping block, such that the clamping blocks are moveably supported in the vertical passage, and
 wherein the vertical guide extends in a diagonal direction with respect to the vertical passage such that each clamping block is moveable in said diagonal direction. 
 
     
     
       14. The drilling vessel according to  claim 1 , wherein the cart transport system further comprises a yoke for the at least one cart, and
 wherein at least the hanger body of a respective cart is rotatably supported in the yoke such that at least the hanger body of the respective cart can be rotated, relative to the yoke, about a vertical axis of the vertical passage of the hanger body of that cart. 
 
     
     
       15. The drilling vessel according to  claim 1 , wherein the tubular string support structure further comprises a bearing support, the bearing support defining an opening concentric with the firing line and the bearing support enabling rotation of the cart when located in the central support position, about a vertical axis of the vertical passage of the hanger body of the respective cart. 
     
     
       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. 
     
     
       17. The drilling vessel according to  claim 1 , wherein the at least one cart comprises two carts,
 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, 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. 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 substantially vertical direction; 
 a drilling deck having a drilling deck top surface; and 
 a tubular string support structure, the support structure comprising:
 a bearing support, the bearing support defining an opening concentric with the firing line; 
 at least one cart, each cart having a hanger body that defines a vertical passage adapted to receive a tubular string supported in the firing line, and wherein 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; and 
 two parallel rails, which rails are provided to support each 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 rails with the firing line passing outside the vertical passage, and 
 a cart transport system comprising one or more transport devices for moving each cart between the secondary position and the central support position, 
 wherein the bearing support enables rotation of the entirety of each cart when in the central support position, about a vertical axis of the vertical passage of the respective cart. 
 
 
     
     
       19. A drilling vessel comprising:
 a hull; 
 a deck, the deck having a top surface and a recess, wherein the recess forms an elongated opening in the deck of the vessel, and the recess extends in a downward direction from the top surface of the deck; 
 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 substantially vertical direction, wherein the drilling tower extends in an upward direction from the top surface of the deck; and 
 a tubular string support structure, which support structure is provided in the recess in the deck, the support structure comprising:
 two parallel rails provided in the recess on opposite sides of the elongated opening and below the top surface of the deck, wherein the firing line passes through said elongated opening between the rails; and 
 two carts, each cart having a hanger body that defines a vertical passage adapted to receive a tubular string supported in the firing line, wherein each cart is supported in the recess, below the top surface of the deck, by the parallel rails such that each cart can be moved between a central support position, above the elongated opening with the firing line passing through the vertical passage, and a secondary position with the firing line passing outside the vertical passage, and 
 a cart transport system, configured for moving the two carts in the recess in the deck along the two parallel rails between the support position and the secondary position, 
 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, 
 wherein the cart transport system is provided with transport devices located on opposite sides of the elongated opening, and each cart can be moved by the transport devices, which transport devices are coupled to opposite sides of the respective cart when that cart is being transported between the central support position and its secondary position.