Earth-boring tools including rotatable cuting element assemblies and related methods of forming and using the same

Abstract

An earth-boring tool comprises a tool body and a cutting element assembly. The assembly comprises a cutting element including a table of polycrystalline hard material secured to a substrate. The table has a front cutting face and a central axis extending through a center of the front cutting face. The assembly also comprises a sleeve having a cavity formed therein and a central axis extending therethrough. A positioning feature and the cutting element may be disposed within the cavity. The positioning feature is configured to radially offset the central axis of the table from the central axis of the sleeve. The cutting element is rotatable about the central axis of the table within the cavity of the sleeve, and the cutting element and positioning feature are rotatable within the cavity of the sleeve such that the central axis of the table revolves about the central axis of the sleeve.

1 . An earth-boring tool for removing subterranean formation material in a wellbore, comprising:
 a tool body; and   a rotatable cutting element assembly comprising:
 a cutting element comprising:
 a substrate; and 
 a table of a polycrystalline hard material secured to the substrate, the table having a front cutting face and a central axis extending through a center of the front cutting face, 
 
 a sleeve fixed to the tool body, the sleeve comprising a cavity having a central axis extending through a center thereof, a portion of the substrate of the cutting element disposed within the cavity of the sleeve; and 
 a positioning feature disposed within the cavity of the sleeve and at least partially encircling the portion of the substrate disposed within the cavity of the sleeve, the positioning feature configured to radially offset the central axis of the table from the central axis of the sleeve; 
 wherein the cutting element is rotatable about the central axis of the table within the cavity of the sleeve; 
 wherein the cutting element and the positioning feature are rotatable within the cavity of the sleeve such that the central axis of the table revolves about the central axis of the sleeve. 
   
     
     
         2 . The earth-boring tool of  claim 1 , wherein the cutting element is configured to rotate about the central axis of the table and wherein the cutting element and positioning feature are rotatable within the cavity of the sleeve such that the central axis of the table revolves about the central axis of the sleeve responsive to engagement of a cutting edge extending about a periphery of the table of the cutting element with a subterranean formation. 
     
     
         3 . The earth-boring tool of  claim 1 , wherein the cutting element is rotatable within the positioning feature and the sleeve. 
     
     
         4 . The earth-boring tool of  claim 1 , wherein the positioning feature entirely encircles the portion of the substrate disposed within the sleeve. 
     
     
         5 . The earth-boring tool of  claim 1 , wherein the positioning feature comprises an indexing mechanism configured to incrementally revolve the central axis of the table about the central axis of the sleeve. 
     
     
         6 . The earth-boring tool of  claim 5 , wherein the indexing mechanism comprises a track provided about an exterior sidewall of the positioning feature and a pin extending through an aperture in the sleeve and engaged with the track. 
     
     
         7 . The earth-boring tool of  claim 1 , wherein at least a portion of the substrate and the table of the cutting element extend over an upper surface of the sleeve. 
     
     
         8 . The earth-boring tool of  claim 1 , wherein a diameter of the table of the cutting element is less than a diameter of the sleeve. 
     
     
         9 . The earth-boring tool of  claim 8 , wherein a cutting edge extending about a periphery of the table of the cutting element does not extend radially beyond an exterior sidewall of the sleeve. 
     
     
         10 . A cutting element assembly, comprising:
 a sleeve comprising a cavity having a central axis extending through a center thereof; and   a cutting element comprising a table of polycrystalline hard material secured to a substrate, the table having a front cutting face and a central axis extending through a center of the front cutting face, at least a portion of the substrate encircled by the cavity of the sleeve;   wherein the central axis of the table is radially offset from the central axis of the sleeve.   
     
     
         11 . The cutting element assembly of  claim 10 , further comprising a positioning feature disposed within the cavity of the sleeve and at least partially encircling the portion of the substrate of the cutting element encircled by the cavity of the sleeve, the positioning feature configured to radially offset the central axis of the table from the central axis of the sleeve. 
     
     
         12 . The cutting element assembly of  claim 11 , wherein the positioning feature is rotatably mounted within the cavity of the sleeve. 
     
     
         13 . The cutting element assembly of  claim 10 , wherein the cutting element is rotatably mounted within the sleeve such that the cutting element may rotate about at least one of the central axis of the table and the central axis of the sleeve. 
     
     
         14 . The cutting element assembly of  claim 11 , wherein:
 the positioning feature comprises a sleeve having a cavity formed therein;   the portion of the cutting element encircled by the cavity of the sleeve further encircled by the cavity of the positioning feature; and   the sleeve of the positioning feature varying in thickness as the sleeve encircles the cutting element.   
     
     
         15 . A method of using a rotatable cutting element, comprising:
 engaging a cutting element of a cutting element assembly with a subterranean formation, the cutting element assembly comprising:
 the cutting element comprising a table of polycrystalline hard material secured to a substrate and a central axis extending through a center of a front cutting face of the table; and 
 a sleeve extending circumferentially about at least a portion of the substrate and having a central axis extending centrally therethrough, the central axis of the cutting element extending parallel to and radially offset from the central axis of the sleeve; 
   rotating the cutting element about the central axis thereof; and   rotating the cutting element within the sleeve such that the central axis of the cutting element revolves about the central axis of the sleeve.   
     
     
         16 . The method of  claim 15 , wherein engaging the cutting element of the cutting element assembly with the subterranean formation comprises engaging a cutting edge extending about a periphery of the front cutting face of the table with the subterranean formation. 
     
     
         17 . The method of  claim 16 , wherein rotating the cutting element within the sleeve such that the central axis of the cutting element revolves about the central axis of the sleeve comprises varying an exposure of the cutting edge of the cutting element relative to an adjacent outermost surface of a bit body to which the cutting element assembly is secured. 
     
     
         18 . The method of  claim 15 , wherein rotating the cutting element within the sleeve such that the central axis of the cutting element revolves about the central axis of the sleeve comprises:
 engaging a formation-engaging feature operatively coupled to the cutting element with the subterranean formation;   rotating the formation-engaging feature responsive to engagement with the subterranean formation; and   rotating the cutting element within the sleeve responsive to rotation of the formation-engaging feature operatively coupled thereto.   
     
     
         19 . The method of  claim 15 , wherein the cutting element assembly further comprises a positioning feature provided radially between the substrate and the sleeve, and wherein rotating the cutting element within the sleeve such that the central axis of the cutting element revolves about the central axis of the sleeve comprises rotating the positioning feature within the sleeve. 
     
     
         20 . The method of  claim 15 , wherein rotating the cutting element about the central axis thereof and rotating the cutting element within the sleeve such that the central axis of the cutting element revolves about the central axis of the sleeve comprises simultaneously rotating the cutting element about the central axis thereof and rotating the cutting element within the sleeve such that the central axis of the cutting element revolves about the central axis of the sleeve.