Drilling rig and method for introducing one or more drilling pipes into an underbalanced well using same

Abstract

A drilling rig includes a mast to be placed above or close to a well and a device connected to the mast for carrying drill pipes to be lowered into the well, which carrying device includes at least three carriers which are connected at different heights to the mast and displaceable in height direction therealong and which are adapted to exert a pulling force or a pressing force as required on the drill pipes. The upper carrier can have a device for rotatingly driving the drill pipes, while the lower carrier, which can be connected releasably to the mast, can have a flexible device for connecting thereof to a blowout preventer placed on the well. A method for introducing one or more drill pipes into an underbalanced well while making use of such a drilling rig includes suspending the drill pipe(s) from the carrying device and urging the pipe(s) downward into the well while exerting a pressing force.

1 - 17 . (canceled) 
   
   
       18 . A drilling rig, comprising:
 a mast adapted to be placed at least one of (a) above and (b) close to a well; and   a carry device, connected to the mast, configured to carry drill pipes to be lowered into the well;   wherein the carry device includes at least three carriers connected at different heights to the mast and displaceable in a height direction along the mast; and   wherein the carriers are adapted to selectively exert at least one of (a) a pulling force and (b) a pressing force on the drill pipes.   
   
   
       19 . The drilling rig according to  claim 18 , wherein at least an upper carrier includes a rotating drive device configured to rotatingly drive the drill pipes. 
   
   
       20 . The drilling rig according to  claim 19 , wherein in that the rotating drive device of the upper carrier includes a top drive. 
   
   
       21 . The drilling rig according to  claim 18 , wherein the carriers are adapted to co-act during a drilling operation when the well is overbalanced, an upper carrier adapted to lower drill pipes in a downward movement into the well, at least one of (a) a middle carrier and (b) a lower carrier adapted to take over and hold the drill pipes fixedly at an end of the downward movement. 
   
   
       22 . The drilling rig according to  claim 18 , wherein a lower carrier is releasably connected to the mast. 
   
   
       23 . The drilling rig according to  claim 22 , wherein the lower carrier includes a flexible connection device configured to connect to a blowout preventer placed on the well. 
   
   
       24 . The drilling rig according to  claim 23 , wherein a middle carrier and a lower carrier are adapted to co-act during an operation when underbalancing prevails in the well, the middle carrier adapted to urge components in a downward stroke into the well, a lower carrier arranged to remain in place and adapted to hold the components fast and to transfer forces that occur into the mast. 
   
   
       25 . The drilling rig according to  claim 18 , further comprising at least one platform connected to the mast and displaceable along the mast in the height direction. 
   
   
       26 . The drilling rig according to  claim 25 , wherein the platform is connected to one of the carriers. 
   
   
       27 . The drilling rig according to  claim 18 , further comprising a supply device configured to supply drill pipes and arranged to co-act with the carry device. 
   
   
       28 . The drilling rig according to  claim 27 , wherein the supply device includes a device adapted to raise the drill pipes from a lying position and transfer the drill pipes to the carry device. 
   
   
       29 . A method for introducing at least one drill pipe into an underbalanced well using a drilling rig including a mast adapted to be placed at least one of (a) above and (b) close to the well and a carry device, connected to the mast, configured to carry drill pipes to be lowered into the well, the carry device including at least three carriers connected at different heights to the mast and displaceable in a height direction along the mast, the carriers adapted to selectively exert at least one of (a) a pulling force and (b) a pressing force on the drill pipes, comprising:
 suspending the drill pipe from the carry device; and   urging the drill pipe downward into the well while exerting the pressing force.   
   
   
       30 . The method according to  claim 29 , further comprising flexibly connecting a lower carrier to a blowout preventer placed on the well and fixing the lower carrier to the mast prior to urging of the drill pipe into the well. 
   
   
       31 . The method according to  claim 30 , wherein a middle carrier urges the drill pipe in a downward stroke into the well and the lower carrier remains in place, holds the drill pipe fast, and transfers forces which occur into the mast. 
   
   
       32 . The method according to  claim 31 , wherein arranged between the middle carrier and the lower carrier is a system of telescopic sluice tubes, of which a stationary outer sluice tube is fixed to the lower carrier and an inner sluice tube is fixed to the middle carrier and moved by the middle carrier. 
   
   
       33 . The method according to  claim 29 , further comprising picking up and presenting the drill pipe to a middle carrier by an upper carrier. 
   
   
       34 . The method according to  claim 29 , further comprising rotatingly driving the drill pipe by an upper carrier. 
   
   
       35 . A drilling rig, comprising:
 a mast adapted to be placed at least one of (a) above and (b) close to a well;   a carry device, connected to the mast, configured to carry drill pipes to be lowered into the well; and   at least one platform connected to the mast and displaceable along the mast in the height direction.   
   
   
       36 . The drilling rig according to  claim 35 , wherein the carry device includes at least three carriers connected at different heights to the mast and displaceable in a height direction along the mast; and
 wherein the platform is connected to one of the carriers.