Continuous drilling system

Abstract

A drill string management apparatus is disclosed. The apparatus may comprise a reel that stores a length of drill string and supplies the drill string to a drilling system. The drill string may be wrapped around a circumference of a reel in a coil. The radius of the coil may be large enough that the drill string is not deformed inelastically by wrapping it around the reel. The apparatus may be designed to allow the drill string to rotate about its longitudinal axis, even as the drill string is wrapped in a coil around the reel.

1 . Apparatus for drilling, the apparatus comprising:
 a reel mounted for rotation about an axis;   a coupling mounted on the reel, the coupling configured for attachment to an uphole end of a drill string and rotatable relative to the reel to allow rotation of the attached drill string around a longitudinal axis of the drill string while the drill string is coiled around the reel.   
     
     
         2 . Apparatus according to  claim 1  wherein a material of the drill string has a yield point and a minimum radius of curvature of the reel is sufficiently large that a maximum stress of the drill string is less than the yield point. 
     
     
         3 . Apparatus according to  claim 2  wherein the maximum stress of the drill string is less than the yield point by a safety factor of  2  or more. 
     
     
         4 . Apparatus according to  claim 1  wherein the coupling comprises a rotary drive. 
     
     
         5 . Apparatus according to  claim 1  comprising a drilling fluid supply system connected to supply drilling fluid to the uphole end of the drill string. 
     
     
         6 . Apparatus according to  claim 5  wherein the drilling fluid supply system comprises a first standpipe extending to a first rotary coupling, a radially-extending conduit extending from the first rotary coupling to a peripheral portion of the reel, the radially extending conduit in fluid communication with a bore of the drill string by way of a second rotary coupling. 
     
     
         7 . Apparatus according to  claim 1  comprising a tensioner operable to apply tension to a tail end of the drill string. 
     
     
         8 . Apparatus according to  claim 7  wherein the tensioner is mounted to the reel and is movable circumferentially relative to the reel. 
     
     
         9 . Apparatus according to  claim 7  wherein the tensioner comprises a tensioner arm extending at an angle to a radius of the reel such that the tensioner arm extends generally tangentially to the reel. 
     
     
         10 . Apparatus according to  claim 7  comprising a an extendible actuator coupled between the tensioner arm and the reel, the extendible actuator operable to alter the angle by moving a distal end of the tensioner arm radially toward or away from the reel. 
     
     
         11 . Apparatus according to  claim 10  wherein the tensioner arm is curved. 
     
     
         12 . Apparatus according to  claim 8  wherein the tensioner comprises first and second carriages mounted to travel along the tensioner arm, each of the first and second carriages comprising a pipe engaging element, and actuators coupled to move the first and second carriages along the tensioner arm. 
     
     
         13 . Apparatus according to  claim 12  wherein the pipe engaging elements comprise elevator plates pivotally mounted to the carriages, the elevator plates comprising cutouts having edge contours dimensioned to receive portions of the drill string between joints of the drill string. 
     
     
         14 . Apparatus according to  claim 12  wherein the actuators comprise first and second chain drives respectively connected to position the first and second carriages. 
     
     
         15 . Apparatus according to  claim 1  comprising a sensor configured to provide a signal to a controller, the signal indicative of a tension in at least a portion of the drill string and wherein the controller is configured to control the tensioner based at least in part on the signal. 
     
     
         16 . Apparatus according to  claim 1  comprising an umbilical cable extending along at least part of the drill string, the umbilical cable comprising a plurality of conductors, the conductors of the umbilical cable connected to corresponding conductors mounted to the reel by way of a rotary connection. 
     
     
         17 . Apparatus according to  claim 16  wherein the umbilical cable extends along substantially all of the drill string. 
     
     
         18 . Apparatus according to  claim 16  wherein the umbilical cable extends along less than an entire length of the drill string. 
     
     
         19 . Apparatus according to  claim 16  wherein the umbilical cable carries electrical power. 
     
     
         20 . Apparatus according to  claim 19  wherein the umbilical cable carries power via a hydraulic conduit. 
     
     
         21 . Apparatus according to  claim 19  wherein the umbilical cable carries power via a pneumatic conduit. 
     
     
         22 . Apparatus according to  claim 19  wherein the umbilical cable carries electrical power to a downhole tractor for axially advancing the drill string. 
     
     
         23 . Apparatus according to  claim 16  wherein the umbilical cable carries optical control signals. 
     
     
         24 . Apparatus according to  claim 16  wherein the umbilical cable carries electrical control signals. 
     
     
         25 . Apparatus according to  claim 16  comprising a pressure sensor connected to deliver downhole pressure readings to surface equipment by way of one or more of the conductors of the umbilical cable. 
     
     
         26 . Apparatus according to  claim 1  wherein the drill string comprises a plurality of tubulars coupled together. 
     
     
         27 . Apparatus according to  claim 26  wherein the plurality of tubulars are coupled together by welding. 
     
     
         28 . Apparatus according to  claim 26  wherein the plurality of tubulars are coupled together by threaded joints. 
     
     
         29 . Apparatus according to  claim 26  wherein the plurality of tubulars are coupled together by shrink fit connections. 
     
     
         30 . Apparatus according to  claim 1  wherein the drill string has an outside diameter of 4 inches or more. 
     
     
         31 . Apparatus according to  claim 1  wherein the reel comprises rollers that support the drill string and the rollers are oriented to rotate when the drill string is rotated about the longitudinal axis of the drill string. 
     
     
         32 . Apparatus according to  claim 31  wherein the rollers are arranged in sets of rollers spaced circumferentially around the reel and different sets of the rollers are offset relative to one another in an axial direction relative to the reel so as to follow helical wraps of the drill string on the reel. 
     
     
         33 . Apparatus according to  claim 1  wherein the reel comprises a peripheral support surface and the peripheral support surface comprises one or more dry-sliding bearing supports to support and allow rotation of the drill string on the reel. 
     
     
         34 . Apparatus according to  claim 1  wherein the reel has a width sufficient to accommodate at least  6  wraps of the drill string. 
     
     
         35 . Apparatus according to  claim 1  wherein the reel comprises a support deck rotatable about the axis relative to at least a portion of the reel. 
     
     
         36 . Apparatus according to  claim 1  wherein the reel has a diameter of at least 30 meters. 
     
     
         37 . Apparatus according to  claim 36  wherein the reel has a diameter of at least 50 meters. 
     
     
         38 . Apparatus according to  claim 37  wherein the reel has a diameter in the range of about 30 to 125 meters. 
     
     
         39 . Apparatus according to  claim 1  comprising a fender structure extending around a periphery of the reel, the fender structure rotatable about the axis of the reel independently of the reel. 
     
     
         40 . Apparatus according to  claim 39  wherein the fender structure comprises circumferentially spaced-apart bars spaced radially outwardly from the support deck. 
     
     
         41 . Apparatus according to  claim 39  wherein the fender structure comprises a wall spaced radially outwardly from the support deck. 
     
     
         42 . Apparatus according to  claim 41  wherein the wall covers one side of an annular enclosure around the support deck wherein the apparatus comprises a heater arranged to heat an interior of the annular enclosure. 
     
     
         43 . Apparatus according to  claim 42  wherein the wall is thermally insulated. 
     
     
         44 . Apparatus according to  claim 1  wherein the reel comprises one or more active retention members, each active retention member operable between a first configuration in engagement with the drill string to prevent the drill string from moving away from the reel and a second configuration in which the drill string is free to move away from the reel. 
     
     
         45 . Apparatus according to  claim 1  wherein the drill string comprises 100 or more tubulars coupled end to end. 
     
     
         46 . Apparatus according to  claim 1 , the apparatus comprising a drilling system comprising plural elevators arranged to carry the weight of a portion of the drill string that is downhole and hoists operable to transfer the weight of the drill string from one of the elevators to another. 
     
     
         47 . Apparatus according to  claim 1 , the apparatus comprising a drilling system comprising:
 a tower;   a pair of parallel chain loops supported for circulation on the tower;   a drive connected to circulate the chain loops;   a plurality of crossheads connected pivotally between the chain loops at spaced-apart locations along the chain loops, each of the crossheads supporting an elevator for a tubular string; and   one or more actuators coupled to adjust an elevation of each elevator relative to the chain loops.   
     
     
         48 . Apparatus according to  claim 46  wherein the elevators are rotatable. 
     
     
         49 . Apparatus according to  claim 1  comprising:
 a second reel mounted for rotation about a second axis; 
 a second coupling mounted on the second reel, the second coupling configured for attachment to an uphole end of a second drill string and rotatable relative to the second reel to allow rotation of the attached second drill string around a longitudinal axis of the second drill string while the second drill string is coiled around the second reel. 
 
     
     
         50 . Apparatus according to  claim 49  comprising a second tensioner operable to apply tension to a tail end of the second drill string. 
     
     
         51  to  81 . (canceled)