[coring tool with retention device]

Abstract

In some embodiments, the invention relates to a sidewall coring tool that includes a tool body, a hollow coring shaft extendable from the tool body, and a formation cutter disposed at a distal end of the hollow coring shaft. The coring tool includes a retention member segmented into a plurality of petals and disposed proximate a distal end of the internal shaft. An internal sleeve may be disposed inside the hollow coring shaft.

1 . A sidewall coring tool, comprising: 
 a tool body;    a hollow coring shaft extendable from the tool body;    a formation cutter disposed at a distal end of the hollow coring shaft; and    a retention member defining one of a plurality of petals, an aperture and combinations thereof, the retention member disposed in the hollow coring shaft.    
   
   
       2 . The sidewall coring tool of  claim 1 , further comprising an internal sleeve disposed inside the hollow coring shaft, and wherein the retention member is connected to the internal sleeve.  
   
   
       3 . The sidewall coring tool of  claim 2 , wherein the retention member is disposed proximate a distal end of the internal sleeve.  
   
   
       4 . The sidewall coring tool of  claim 2 , wherein the internal sleeve comprises a non-rotating sleeve.  
   
   
       5 . The sidewall coring tool of  claim 2 , wherein the internal sleeve comprises a radial notch such that the petals of the retention member can be positioned radially outward into the notch.  
   
   
       6 . The sidewall coring tool of  claim 5 , wherein the retention member has a petal circumference that is substantially the same as an inner diameter of the internal sleeve.  
   
   
       7 . The sidewall coring tool of  claim 2 , further comprising a piston disposed inside the internal sleeve and axially moveable with respect to the internal sleeve.  
   
   
       8 . The sidewall coring tool of  claim 2 , further comprising a check valve disposed in the internal sleeve.  
   
   
       9 . The sidewall coring tool of  claim 8 , wherein the check valve is disposed in a proximal end of the internal sleeve.  
   
   
       10 . The sidewall coring tool of  claim 9 , wherein the check valve enables a fluid to flow out of the internal sleeve.  
   
   
       11 . The sidewall coring tool of  claim 1 , wherein an inner diameter of the internal sleeve is substantially the same as an inner diameter of the formation cutter.  
   
   
       12 . The sidewall coring tool of  claim 1 , wherein an inner diameter of the internal sleeve is larger than an inner diameter of the formation cutter.  
   
   
       13 . The sidewall coring tool of  claim 1 , wherein the internal sleeve comprises a bladder configured to apply radial pressure to a core sample when the bladder is selectively filled with a fluid.  
   
   
       14 . The sidewall coring tool of  claim 1 , wherein the plurality of petals comprises 3 petals.  
   
   
       15 . The sidewall coring tool of  claim 1 , wherein the plurality of petals overlap.  
   
   
       16 . The sidewall coring tool of  claim 1 , wherein the plurality of petals are separated by gaps.  
   
   
       17 . The sidewall coring tool of  claim 1 , wherein the retention member comprises perforations.  
   
   
       18 . The sidewall coring tool of  claim 17 , wherein the perforations are circumferential perforations disposed outside a petal circumference.  
   
   
       19 . The sidewall coring tool of  claim 17 , wherein the perforations are radial perforations disposed at least partially inside a petal circumference.  
   
   
       20 . The sidewall coring tool of  claim 1 , wherein the plurality of petals are adjacent.  
   
   
       21 . The sidewall coring tool of  claim 1 , wherein the retention member is constructed of rubber.  
   
   
       22 . The sidewall coring tool of  claim 1 , wherein the retention member is rounded and extrudes towards a distal end of hollow coring shaft.  
   
   
       23 . The sidewall coring tool of  claim 1 , wherein the retention member is rounded and extrudes towards a proximal end of the hollow coring shaft.  
   
   
       24 . A method for taking a core sample, comprising: 
 extending a coring bit into a formation, the coring bit having a retention member segmented into a plurality of petals;    receiving the core sample in the coring bit; and    retaining the core sample in the coring bit with the retention member while withdrawing the coring bit from the formation.    
   
   
       25 . The method of  claim 24 , further comprising selectively filling a bladder with a fluid to apply a radial pressure to the core sample.  
   
   
       26 . The method of  claim 24 , wherein the retention member is connected to an internal sleeve disposed in the coring bit and the core sample is received in the internal sleeve.  
   
   
       27 . A sidewall coring tool, comprising: 
 a tool body;    a hollow coring shaft extendable from the tool body;    a formation cutter disposed at a distal end of the hollow coring shaft;    an internal sleeve disposed inside the hollow coring shaft; and    at least one retention mechanism selected from the group consisting of a piston and a check valve, wherein the piston is disposed in the internal sleeve and moveable with respect to the internal sleeve, and the check valve is disposed in the internal sleeve.    
   
   
       28 . The sidewall coring tool of  claim 27 , wherein the at least one retention mechanism is the piston.  
   
   
       29 . The sidewall coring tool of  claim 28 , further comprising a seal disposed between the piston and the internal sleeve.  
   
   
       30 . The sidewall coring tool of  claim 28 , wherein an inner diameter of the internal sleeve is substantially the same as an inner diameter of the formation cutter.  
   
   
       31 . The sidewall coring tool of  claim 28 , further comprising a check valve operatively connected to the internal sleeve.  
   
   
       32 . The sidewall coring tool of  claim 27 , further comprising a retention member segmented into petals disposed proximate an opening at a distal end of the internal sleeve.  
   
   
       33 . A method for taking a core sample, comprising: 
 extending a coring bit into a formation;    receiving the core sample in an internal sleeve having a piston disposed therein such that the piston is moveable with respect to the internal sleeve; and    withdrawing the coring bit from the formation.    
   
   
       34 . The method of  claim 33 , further comprising selectively filling a bladder with a fluid to apply a radial pressure to the core sample.