Radial Clamping/Sealing System and Drilling System Provided Therewith for (Semi)-Continuous Drilling a Borehole, Drilling Rig Comprising Such System, and Method There For

Abstract

Invention relates to a system and associated method for continuous and/or semi-continuous drilling a borehole, comprising:—a first stationary housing;—a rotatable housing comprising a longitudinal opening for receiving a drill string; and—a radial clamping system configured for holding and clamping the box end of the drill string in substantially radial direction with respect to the rotatable housing;—a first direct sealing system in use arranged between drill pipe and the rotatable housing;—a second indirect sealing system in use arranged between the rotatable housing and the stationary housing;—a mechanical and/or hydraulic transmission configured for radial activation of the radial clamping system; and—a first drive configured for rotating the rotatable housing with the drill string.

1 . A system for continuous and/or semi-continuous drilling a borehole, comprising:
 a first stationary housing;   a rotatable housing comprising a longitudinal opening for receiving a drill string; and   a radial clamping system configured for holding and clamping a box end of the drill string in substantially radial direction with respect to the rotatable housing;   a first direct sealing system in use arranged between drill pipe and the rotatable housing;   a second indirect sealing system in use arranged between the rotatable housing and the stationary housing;   a mechanical and/or hydraulic transmission configured for radial activation of the radial clamping system; and   a first drive configured for rotating the rotatable housing with the drill string.   
     
     
         2 . The system according to  claim 1 , further comprising an axial support system for longitudinally fixating a drill string on the deviated area of the drill pipe. 
     
     
         3 . The system according to  claim 1 , further comprising a second rotatable housing comprising:
 a second stationary housing wherein the rotatable housing is axially fixed; and   a radial clamping system configured for holding and clamping the pin end of a drill pipe in a substantially radial direction with respect to the rotatable housing;   wherein the second stationary housing is longitudinally movable within the first stationary housing and comprises a third sealing system arranged between the first and second stationary housing.   
     
     
         4 . The system according to  claim 3 , wherein the first and second rotatable housing are located above each other in a first stationary housing, and the system further comprises:
 a separating sealing system for creating two pressure chambers between the first and second rotatable housing; and   radial located fluid inlets in the first stationary housing for regulating the fluid pressure in aforementioned created fluid chambers.   
     
     
         5 . The system with a rotatable housing according to  claim 2 , further comprising a hydraulic transmission system and/or a mechanical transmission system configured for the activation of the axial support system. 
     
     
         6 . The system according to  claim 1 , further comprising a hydraulic actuating system for the activation of the first direct seal between the pipe and rotatable housing. 
     
     
         7 . The system according to  claim 1 , wherein the clamping means are activated in a radial direction through the axial compression of a flexible material. 
     
     
         8 . The system according to  claim 1 , wherein the clamping means and/or the axial support means comprise inserts enabling the handling of different drill pipe sizes. 
     
     
         9 . The system according to  claim 1 , wherein the first and/or second seals comprise sub-seals and/or seal parts. 
     
     
         10 . The system according to  claim 4 , further comprising;
 a gearbox comprising a system with a drive configured for driving at least one of the rotatable housings for enabling a coupling or uncoupling motion of drill pipes; and   a longitudinally movable gearing configured for continuously driving second rotatable housing during longitudinal motion.   
     
     
         11 . The system according to  claim 1 , wherein the first direct sealing system further comprises:
 a flexible material configured for converting a mechanical actuation force into radial compression; and   a replaceable first direct seal insert arranged such that the insert can be actuated by the flexible material and such that the handling of different drill pipe sizes is enabled.   
     
     
         12 . A drilling rig comprising a system according to  claim 1 , and further comprising;
 a topdrive; and   a guide track configured for enabling translation of the stationary housing in the axial direction of the drill string under the topdrive.   
     
     
         13 . A method for continuous and/or semi-continuous drilling a borehole comprising providing a system according to  claim 1 . 
     
     
         14 . The method according to  claim 13 , comprising the steps of:
 activation of the axial support pads to provide an elevator function of the drill string;   activation of the radial clamping system to fixate the drill pipe in substantially radial direction with respect to the rotatable housing; and   activation of the first direct sealing system.   
     
     
         15 . The method according to  claim 13 , further comprising the steps of:
 injecting drilling fluid and rotating the drill string with the topdrive, in use starting at the top of the derrick and moving down, with the continuous drilling system deactivated such that the drill string moves through the longitudinal opening;   clamping the continuous drilling system to the topdrive connection with the drill string, with the first rotatable housing clamping, sealing and supporting the box end of the drill string and the second rotatable housing, clamping and sealing the pin end of the topdrive, and executing the said drilling functions;   the continuous drilling system taking over the functions of hoisting the drill string, rotating the drill string and applying torque to the drill string of the topdrive with the first rotatable housing, filling the fluid chamber between the first and second rotatable housing with drilling fluid with a pressure equal to the injected drilling fluid by the topdrive;   the second rotatable housing uncoupling the connection between the drill string and the topdrive, whereafter the separating seal system seals is activated, the drilling fluid injection is taken over by the drilling system, and the drilling fluid injection by the topdrive is stopped;   removing the drilling fluid from the upper fluid chamber, the second rotatable housing deactivating the clamping and sealing function on the pin end of the topdrive, and the topdrive connecting to a new pipe section;   inserting the new pipe section in the continuous drilling system, and the second rotatable housing clamping and sealing the pin end of the new pipe section, filling the upper fluid chamber with drilling fluid with a pressure equal to the injected drilling fluid by the drilling system;   deactivating the separating seal system and the second rotatable housing rotating the new drill pipe section, wherein the drilling fluid injection is taken over by the topdrive and stopping the drilling fluid injection by the drilling system;   coupling the drill string and the new drill pipe section, while the first rotatable housing is still executing the functions of hoisting the drill string, rotating the drill string and applying torque to the drill string, and after completion removing the drilling fluid from the fluid chamber; and   the topdrive taking over the functions of hoisting the drill string, rotating the drill string and applying torque to the drill string, in addition to the injection of drilling fluid, and the drilling system deactivating the clamping, sealing and supporting means.   
     
     
         16 . The method according to  claim 15 , further comprising the step of repeating the method steps. 
     
     
         17 . The method for continuous and/or semi-continuous tripping with or without fluid circulation comprising the step of providing a drilling system according to  claim 1 . 
     
     
         18 . The method according to  claim 17 , further comprising the steps of:
 moving the drilling system upwards starting at a drill floor, and rotating, sealing and hoisting the drill string at the upper box end, and injecting drilling fluid, wherein the topdrive is located above the drill string in a derrick and is inserted in the deactivated second rotatable housing;   the continuous drilling system clamping and sealing the pin end of the topdrive with the second rotatable housing, filling the upper fluid chamber with drilling fluid with a pressure equal to the injected drilling fluid by the continuous drilling system;   opening the separating seals and rotating the pin end of the topdrive, the second rotatable housing moving down in the first stationary housing, enabling the coupling of the topdrive and the drill string, and stopping he drilling fluid injection from the drilling system and taking over by the topdrive;   taking over the functions of hoisting and rotating the drill string by the topdrive and deactivating the clamping, supporting and sealing means of the first and second rotatable housing;   moving down the drilling system to a following drill pipe connection, and the first rotatable housing clamping, supporting and sealing the box end of the connection, while the second rotatable housing clamping and sealing the pin end of the connection;   taking over the functions of hoisting and rotating the drill string from the topdrive by the drilling system, and filling the fluid chamber with drilling fluid with a pressure equal to the injected drilling fluid by the topdrive;   the second rotatable housing delivering the break out torque to enable the decoupling of the drill string and the upper drill pipe section, closing the separating seals and taking over the function of injecting drilling fluid by the drilling system; and   removing the drilling fluid from the upper fluid chamber in the continuous drilling system, the second rotatable housing deactivating the clamping and sealing function on the pin end of the topdrive, and the topdrive relocating the decoupled pipe section.   
     
     
         19 . The method according to  claim 18 , further comprising the step of repeating the method steps. 
     
     
         20 . The method according to  claim 18 , further comprising the steps of:
 the topdrive lifting the drill string out of the borehole with the elevator until at least two pipe sections are above the drill floor;   clamping the box end and pin end of the pipe section connection just above the drilling floor by the first and second rotatable housing, respectively;   the second rotatable housing delivering a break out torque for uncoupling the upper drill pipe section;   the topdrive lifting and storing the uncoupled pipe section, the drilling system taking over the hoisting function of the rotary slips and lifting the drill string further out of the borehole;   supporting the drill string in rotary slips on a drill floor and moving the drilling system downward to the drill floor;   relocating the topdrive above the drill string and connecting topdrive to the upper pipe section of the drill string with the elevator; and   the topdrive taking over the hoisting function of the continuous drilling system.   
     
     
         21 . The method according to  claim 20 , further comprising the steps of repeating the method steps.