Core sample handling device

Abstract

A device for handling core samples during a core sample drilling operation is disclosed. In use, the core sample is received in a string of inner tubes within a drill string. The device includes a clamp and a coupling mechanism. The clamp is configured to grip a lower inner tube below a joint between the lower inner tube and an adjacent upper inner tube of the string of inner tubes, with the lower tube received in the drill string and with the joint exposed above a top end of the drill string. The coupling mechanism is configured to engage the upper inner tube and/or the joint and operate to uncouple the upper inner tube from the lower inner tube.

1 . A device for handling core samples during a core sample drilling operation, in use the core sample received in a string of inner tubes within a drill string of drilling rods, the device comprising:
 a clamp configured to grip a lower inner tube below a joint between the lower inner tube and an adjacent upper inner tube of the string of inner tubes, with the lower inner tube received in the drill string and with the joint exposed above a top end of the drill string;   and   a coupling mechanism configured to:
 engage the upper inner tube and/or the joint; and 
 operate to uncouple the upper inner tube from the lower inner tube; 
   the device further comprising a cutting or breaking mechanism, to cut or break an exposed portion of the core between the upper and lower inner tubes after the upper and lower inner tubes have been uncoupled and separated.   
     
     
         2 . The device as claimed in  claim 1 , wherein the device comprises a positioning apparatus configured to move the clamp relative to the drill string to engage an upper end of the lower inner tube. 
     
     
         3 . The device as claimed in  claim 1 , wherein the positioning apparatus is configured to orient the clamp to position an inner tube carried by the clamp with a longitudinal axis of the tube coincident with a longitudinal axis of the drill string. 
     
     
         4 . The device as claimed in  claim 1 , wherein the positioning apparatus is configured to move the clamp in a direction lateral to the longitudinal axis of the drill string. 
     
     
         5 . The device as claimed in  claim 1 , wherein the coupling mechanism is configured to rotate the upper inner tube to uncouple the upper inner tube from the adjacent lower inner tube. 
     
     
         6 . The device as claimed in  claim 1 , wherein the cutting or breaking mechanism provides a “witness” mark on the core sample. 
     
     
         7 . The device as claimed in  claim 1 , wherein the device comprises a marking mechanism to provide a longitudinal mark to an exposed portion of the core between the upper and lower inner tubes after the upper and lower inner tubes have been uncoupled and separated, to preserve a known orientation of adjacent portions of the core after cutting or breaking. 
     
     
         8 . A method for drilling and recovering core samples from a formation, the method comprising:
 i) providing a drill rig with a drill string for drilling into a formation to extract a core sample;   ii) advancing an inner tube into the drill string to be received therein with an upper end of the inner tube exposed above a top end of the drill string;   iii) coupling a next inner tube to the upper end of the inner tube received in the drill string to form a string of inner tubes comprising at least an uppermost inner tube and an adjacent second-uppermost inner tube;   iv) lowering the string of inner tubes to the bottom of the drill string;   v) drilling into the formation to a depth greater than the length of a single inner tube of the string of inner tubes and less than or equal to a length of the string of inner tubes to receive the core sample within the string of inner tubes;   vi) recovering the string of inner tubes with core sample received therein to expose a lower end of the uppermost inner tube and an upper end of the adjacent second uppermost inner tube coupled thereto above the top end of the drill string with the second upper most inner tube received in the drill string;   vii) uncoupling and separating the uppermost inner tube from the adjacent second uppermost inner tube to expose a portion of the core sample therebetween;   viii) cutting or breaking the core sample through the exposed portion of the core sample;   ix) removing the uppermost inner tube with a corresponding portion of the core sample therein from the drill rig;   x) recovering the second uppermost inner tube with a corresponding portion of the core sample therein from the drill string and removing from the drill rig.   
     
     
         9 . The method of  claim 8  wherein in step iii) the method comprises:
 iii) a) coupling the next inner tube to the exposed upper end of the inner tube received in the drill string; 
 iii) b) advancing the coupled inner tubes into the drill string to be received therein with an upper end of an uppermost inner tube exposed above the top end of the drill string; 
 iii) c) repeating steps iii) a) and iii) b) until a desired number of inner tubes are coupled together to form the string of inner tubes. 
 
     
     
         10 . The method of  claim 8 , wherein in step x) the method comprises: repeating steps vi) to ix) until an upper end of a lowermost inner tube of the string of inner tubes is above the upper end of the drill string; and recovering the lower most inner tube with a corresponding portion of the core sample therein from the drill string and removing from the drill rig. 
     
     
         11 . The method as claimed in  claim 8 , wherein the method comprises providing a clamp and in step ii) the method comprises clamping the upper end of the inner tube. 
     
     
         12 . The method as claimed in  claim 8 , wherein the method comprises providing a coupling mechanism configured to couple the inner tubes and in step iii) the method comprises: clamping the upper end of the inner tube exposed above the upper end of the drill string with the clamp, engaging the coupling mechanism with the next inner tube, and operating the coupling mechanism to couple the next inner tube to the upper end of the inner tube received in the drill string. 
     
     
         13 . The method as claimed in  claim 8 , wherein in step vii) the method comprises: moving the uncoupled inner tube along an axis of the drill string to expose the portion of the core sample. 
     
     
         14 . The method as claimed in  claim 13 , wherein the method comprises providing a cutting or breaking mechanism and in step viii) the method comprises: operating the cutting or breaking mechanism to cut the exposed portion of the core, and wherein the cutting or breaking mechanism is configured to move between a retracted position and an extended position to cut or break the core, and in step viii) the method comprises: after cutting or breaking the core, operating the cutting or breaking mechanism to remain in the extended position or move to an intermediate position to support a portion of the core sample above the cutting or breaking mechanism and retain the portion of the core sample in the uncoupled uppermost inner tube. 
     
     
         15 . A method for uncoupling, or coupling, an innertube from a string of innertubes in a drilling rig (whether uphill or downhill drilling), to retrieve a core sample, wherein the method comprises:
 separately clamping one innertube and an adjacent innertube to which it is connected in the string via at least one clamp;   wherein at least one of clamps can move longitudinally relative to the string of innertubes.   
     
     
         16 . The method as claimed as  claimed in 15  wherein:
 at least one clamp can move one uncoupled length of inner tube longitudinally relative to an adjacent length of inner tube. 
 
     
     
         17 . The method for uncoupling an innertube from a string of innertubes in a drilling rig (whether uphill or downhill drilling), to retrieve a core sample, as claimed in  claim 15  wherein the method further comprises:
 at least one clamp associated with at least one of said adjacent innertubes is in the form of a pair of jaws comprising a roller configured to allow: 
 advancing empty inner tubes into the top end of a drill rod; 
 removing the inner tube(s) from the top end of a drill rod; 
 resisting rotation of an innertube to allow the apparatus to join or separate additional inner tubes to be lowered or withdrawn from the drill rods.