Telescoping core barrel

Abstract

A coring assembly comprises a shoe and a tubular body having a first end coupled to the shoe. An inner sleeve is releasably coupled to the shoe and has a first end disposed within the shoe and a second end that is slidably engaged with the tubular body. A middle sleeve is slidably engaged with the tubular body and releasably coupled to the shoe. At least a portion of the middle sleeve is disposed within an annulus defined by the inner sleeve and the tubular body.

What is claimed is: 
     
         1 . A coring assembly comprising:
 a shoe;   a tubular body having a first end coupled to the shoe;   an inner sleeve releasably coupled to the shoe, wherein the inner sleeve has a first end disposed within the shoe and a second end that is slidably engaged with the tubular body; and   a middle sleeve slidably engaged with the tubular body and releasably coupled to the shoe, wherein at least a portion of the middle sleeve is disposed within an annulus defined by the inner sleeve and the tubular body.   
     
     
         2 . The coring assembly of  claim 1 , further comprising a stop member coupled to the inner sleeve and operable to limit longitudinal movement of the inner sleeve relative to the middle sleeve. 
     
     
         3 . The coring assembly of  claim 1 , further comprising one or more stabilizers disposed on an outer surface of the middle sleeve and slidably engaged with the tubular body. 
     
     
         4 . The coring assembly of  claim 1 , further comprising a coring bit, wherein the shoe is at least partially disposed within the coring bit. 
     
     
         5 . The coring assembly of  claim 4 , further comprising an outer barrel coupled to the coring bit, wherein the tubular body is disposed within the outer barrel. 
     
     
         6 . The coring assembly of  claim 4 , wherein the shoe comprises a core catcher that is at least partially disposed within the coring bit. 
     
     
         7 . The coring assembly of  claim 6 , wherein the first end of the inner sleeve is at least partially disposed within the core catcher. 
     
     
         8 . The coring assembly of  claim 1 , further comprising:
 one or more inner sleeve frangible members that releasably couple the inner sleeve to the shoe; and   one or more second frangible members that releasably couple the middle sleeve to the shoe.   
     
     
         9 . A coring assembly comprising:
 a coring bit;   an outer barrel having a first end coupled to the coring bit;   an inner barrel rotatably disposed within the outer barrel;   a shoe coupled to the inner barrel and at least partially disposed within the coring bit;   a middle sleeve slidably engaged with the inner barrel and releasably coupled to the shoe; and   an inner sleeve releasably coupled to the shoe, wherein the inner sleeve has a first end at least partially disposed within the shoe, a body at least partially disposed within the middle sleeve, and a second end slidably engaged with the inner barrel.   
     
     
         10 . The coring assembly of  claim 9 , further comprising a stop member coupled to the inner sleeve and operable to limit longitudinal movement of the inner sleeve relative to the middle sleeve. 
     
     
         11 . The coring assembly of  claim 9 , further comprising one or more stabilizers disposed on an outer surface of the middle sleeve and slidably engaged with the inner barrel. 
     
     
         12 . The coring assembly of  claim 9 , wherein the shoe comprises a core catcher that is at least partially disposed within the coring bit. 
     
     
         13 . The coring assembly of  claim 12 , wherein the first end of the inner sleeve is at least partially disposed within the core catcher. 
     
     
         14 . The coring assembly of  claim 9 , further comprising:
 one or more inner sleeve frangible members that releasably couple the inner sleeve to the shoe; and   one or more second frangible members that releasably couple the middle sleeve to the shoe.   
     
     
         15 . A method for coring comprising:
 rotating a coring bit in a formation to form a core;   receiving the core into an inner sleeve that is coupled to a shoe and has a first end disposed within the coring bit;   releasing the inner sleeve from the shoe;   moving the inner sleeve longitudinally relative to a middle sleeve that is releasably coupled to the shoe;   receiving the core into the middle sleeve;   releasing the middle sleeve from the shoe; and   moving the middle sleeve longitudinally relative to a tubular body that is coupled to the shoe, wherein the inner sleeve and the middle sleeve are both slidably engaged with the tubular body.   
     
     
         16 . The method of  claim 15 , wherein a stop member is coupled to the inner sleeve and is operable to limit longitudinal movement of the inner sleeve relative to the middle sleeve. 
     
     
         17 . The method of  claim 15 , wherein one or more stabilizers are disposed on an outer surface of the middle sleeve and slidably engaged with the tubular body. 
     
     
         18 . The method of  claim 15 , wherein the shoe comprises a core catcher that is at least partially disposed within the coring bit. 
     
     
         19 . The method of  claim 15 , wherein the first end of the inner sleeve is at least partially disposed within the core catcher. 
     
     
         20 . The method of  claim 15 , wherein the inner sleeve is coupled to the shoe by one or more inner sleeve frangible members and the middle sleeve is coupled to the shoe by one or more second frangible members.