Turbodrill Using a Balance Drum

Abstract

A turbodrill using a balance drum. The turbodrill may include a housing having an upper end that is configured to be coupled to a drill string. The turbodrill may also include a rotatable shaft having a lower end configured to be coupled to a drill bit. The turbodrill may further include a balance drum assembly coupled to the shaft within the housing. In addition, the turbodrill may include a compliant mounting disposed between the balance drum assembly and the housing, where the compliant mounting is configured to allow displacement of the balance drum assembly within the housing.

What is claimed is: 
     
         1 . A turbodrill, comprising:
 a housing having an upper end that is configured to be coupled to a drill string;   a rotatable shaft having a lower end configured to be coupled to a drill bit;   a balance drum assembly coupled to the shaft within the housing; and   a compliant mounting disposed between the balance drum assembly and the housing, wherein the compliant mounting is configured to allow displacement of the balance drum assembly within the housing.   
     
     
         2 . The turbodrill of  claim 1 , wherein the balance drum assembly comprises:
 a drum rotor coupled to the shaft, wherein the drum rotor is configured to rotate with the shaft; and   a drum stator coupled to the drum rotor and comprising a cap, wherein the compliant mounting is disposed between the cap and the housing.   
     
     
         3 . The turbodrill of  claim 2 , wherein an uphole end of the compliant mounting is coupled to a downhole end of the cap, and wherein a downhole end of the compliant mounting is coupled to an inner shoulder of the housing. 
     
     
         4 . The turbodrill of  claim 2 , wherein the compliant mounting is configured to resist rotation of the drum stator within the housing. 
     
     
         5 . The turbodrill of  claim 1 , wherein the compliant mounting comprises a coil spring, a Belleville spring, a machine spring, or a wave spring. 
     
     
         6 . The turbodrill of  claim 1 , wherein the compliant mounting is configured to allow lateral displacement of the balance drum assembly relative to a central axis of the housing. 
     
     
         7 . The turbodrill of  claim 1 , wherein the compliant mounting is configured to allow angular displacement of the balance drum assembly relative to a central axis of the housing. 
     
     
         8 . The turbodrill of  claim 1 , further comprising one or more rotational inhibitors coupled between the housing and the balance drum assembly, wherein the rotational inhibitors are configured to restrain the balance drum assembly. 
     
     
         9 . The turbodrill of  claim 8 , wherein the rotational inhibitors are configured to resist rotation of a drum stator within the housing. 
     
     
         10 . The turbodrill of  claim 8 , wherein the one or more rotational inhibitors have a first end coupled to the housing and a second end engaging the cap. 
     
     
         11 . The turbodrill of  claim 8 , wherein the one or more rotational inhibitors comprise one or more pins, one or more springed pins, one or more cables, or combinations thereof. 
     
     
         12 . A turbodrill, comprising:
 a housing having an upper end that is configured to be coupled to a drill string;   a rotatable shaft having a lower end configured to be coupled to a drill bit;   a balance drum assembly coupled to the shaft within the housing; and   an elastomeric mounting disposed between the balance drum assembly and the housing, wherein the elastomeric mounting is configured to allow displacement of the balance drum assembly within the housing.   
     
     
         13 . The turbodrill of  claim 12 , wherein the balance drum assembly comprises:
 a drum rotor coupled to the shaft, wherein the drum rotor is configured to rotate with the shaft; and   a drum stator coupled to the drum rotor and comprising a cap, wherein the elastomeric mounting is disposed between the cap and the housing.   
     
     
         14 . The turbodrill of  claim 13 , wherein a top portion of the elastomeric mounting is coupled to the cap and to an inner wall of the housing. 
     
     
         15 . The turbodrill of  claim 14 , wherein a bottom portion of the elastomeric mounting comprises:
 a downhole end coupled to an inner shoulder of the housing; and   an uphole end coupled to a downhole end of the cap and a downhole end of the top portion.   
     
     
         16 . The turbodrill of  claim 15 , wherein the top portion has greater flexibility than the bottom portion. 
     
     
         17 . The turbodrill of  claim 12 , wherein the elastomeric mounting is configured to allow lateral displacement of the balance drum assembly relative to a central axis of the housing. 
     
     
         18 . The turbodrill of  claim 12 , wherein the elastomeric mounting is configured to allow angular displacement of the balance drum assembly relative to a central axis of the housing. 
     
     
         19 . A turbodrill, comprising:
 a housing having an upper end that is configured to be coupled to a drill string;   a rotatable shaft having a lower end configured to be coupled to a drill bit;   a balance drum assembly coupled to the shaft within the housing; and   a compliant rod mechanism coupled to an uphole end of the balance drum assembly, wherein the compliant rod mechanism is configured to allow displacement of the balance drum assembly within the housing.   
     
     
         20 . The turbodrill of  claim 19 , wherein the balance drum assembly comprises:
 a drum rotor coupled to the shaft, wherein the drum rotor is configured to rotate with the shaft; and   a drum stator coupled to the drum rotor, wherein the drum stator is disposed between the compliant rod mechanism and the drum rotor.   
     
     
         21 . The turbodrill of  claim 19 , wherein the compliant rod mechanism comprises:
 a flex rod having a downhole end coupled to the drum stator; and   a rod retainer having a downhole end coupled to the flex rod, wherein the rod retainer is disposed on an inner shoulder of the housing.   
     
     
         22 . The turbodrill of  claim 21 , wherein the flex rod comprises a cable attachment, a coil spring, a rod composed of titanium, or flexible steel. 
     
     
         23 . The turbodrill of  claim 21 , wherein the flex rod is configured to resist rotation of the drum stator within the housing. 
     
     
         24 . The turbodrill of  claim 19 , wherein the compliant rod mechanism is configured to allow lateral displacement or angular displacement of the balance drum assembly relative to a central axis of the housing. 
     
     
         25 . The turbodrill of  claim 24 , wherein the compliant rod mechanism is configured to allow the lateral displacement or angular displacement via bending of the compliant rod mechanism. 
     
     
         26 . A turbodrill, comprising:
 a housing having an upper end that is configured to be coupled to a drill string;   a rotatable shaft having a lower end configured to be coupled to a drill bit;   a balance drum assembly coupled to the shaft within the housing; and   a rod with one or more compliant joints coupled to an uphole end of the balance drum assembly, wherein the rod with one or more compliant joints is configured to allow displacement of the balance drum assembly within the housing.   
     
     
         27 . The turbodrill of  claim 26 , wherein the balance drum assembly comprises:
 a drum rotor coupled to the shaft, wherein the drum rotor is configured to rotate with the shaft; and   a drum stator coupled to the drum rotor, wherein the drum stator is disposed between the rod with one or more compliant joints and the drum rotor.   
     
     
         28 . The turbodrill of  claim 26 , wherein the rod with one or more compliant joints comprises:
 a rod having a downhole end coupled to the drum stator via a lower compliant joint; and   a rod retainer having a downhole end coupled to the rod via an upper compliant joint, wherein the rod retainer is disposed on an inner shoulder of the housing.   
     
     
         29 . The turbodrill of  claim 26 , wherein the one or more compliant joints comprise one or more universal joints or one or more constant-velocity (CV) joints. 
     
     
         30 . The turbodrill of  claim 26 , wherein the rod with one or more compliant joints is configured to allow lateral displacement or angular displacement of the balance drum assembly relative to a central axis of the housing. 
     
     
         31 . The turbodrill of  claim 30 , wherein the rod with one or more compliant joints is configured to allow the lateral displacement or angular displacement via pivoting of the one or more compliant joints. 
     
     
         32 . A turbodrill, comprising:
 a housing having an upper end that is configured to be coupled to a drill string;   a rotatable shaft having a lower end configured to be coupled to a drill bit;   a balance drum assembly coupled to the shaft within the housing; and   a flex shaft having an uphole end coupled to the balance drum assembly and a downhole end coupled to the rotatable shaft, wherein the flex shaft is configured to allow displacement of the balance drum assembly within the housing.   
     
     
         33 . The turbodrill of  claim 32 , wherein the balance drum assembly comprises:
 a drum rotor coupled to the uphole end of the flex shaft, wherein the drum rotor is configured to rotate with the flex shaft; and   a drum stator coupled to the drum rotor and comprising a cap and a sleeve, wherein the sleeve is disposed on an inner shoulder of the housing.   
     
     
         34 . The turbodrill of  claim 33 , wherein the drum rotor is coupled to the uphole end of the flex shaft within an inner bore of the drum rotor. 
     
     
         35 . The turbodrill of  claim 33 , wherein the drum rotor is coupled to the uphole end of the flex shaft outside of an inner bore of the drum rotor. 
     
     
         36 . The turbodrill of  claim 32 , wherein the flex shaft is configured to allow lateral displacement or angular displacement of the balance drum assembly relative to a central axis of the housing. 
     
     
         37 . The turbodrill of  claim 36 , wherein the flex shaft is configured to allow the lateral displacement or angular displacement via bending of the flex shaft. 
     
     
         38 . The turbodrill of  claim 32 , wherein one or more vents are placed proximate to the balance drum assembly. 
     
     
         39 . A turbodrill, comprising:
 a housing having an upper end that is configured to be coupled to a drill string;   a rotatable shaft having a lower end configured to be coupled to a drill bit;   a balance drum assembly coupled to the shaft within the housing; and   a spherical bearing assembly disposed between the balance drum assembly and the housing, wherein the spherical bearing assembly is configured to allow displacement of the balance drum assembly within the housing.   
     
     
         40 . The turbodrill of  claim 39 , wherein the balance drum assembly comprises:
 a drum rotor coupled to the shaft, wherein the drum rotor is configured to rotate with the shaft; and   a drum stator coupled to the drum rotor and comprising a cap, wherein the spherical bearing assembly is disposed between the cap and the housing.   
     
     
         41 . The turbodrill of  claim 40 , wherein the spherical bearing assembly comprises a top spherical seat having a downhole end configured to mate to an uphole end of a bottom spherical seat. 
     
     
         42 . The turbodrill of  claim 41 , wherein the downhole end of the top spherical seat is generally convex, and wherein the uphole end of the bottom spherical seat is generally concave. 
     
     
         43 . The turbodrill of  claim 41 , wherein the downhole end of the bottom spherical seat is disposed on an inner shoulder of the housing. 
     
     
         44 . The turbodrill of  claim 41 , wherein a clearance formed by an outer diameter of the bottom spherical seat and an inner diameter of the housing is configured to allow for lateral displacement of the balance drum assembly. 
     
     
         45 . The turbodrill of  claim 41 , wherein the top spherical seat and the bottom spherical seat may be configured to rotate with respect to one another in order to allow for angular displacement of the balance drum assembly.