Downhole Friction Control Systems and Methods

Abstract

A downhole friction control system comprises a downhole sub to attach to a drill string and a vibration component. The vibration component is mechanically coupled to the downhole sub to generate a selected vibration in the drill string when the downhole sub is attached to the drill string. Additional apparatus, methods, and systems are disclosed.

What is claimed is: 
     
         1 . A system, comprising:
 a downhole sub to attach to a drill string; and   a vibration component mechanically coupled to the downhole sub to generate a selected vibration in the drill string when the downhole sub is attached to the drill string.   
     
     
         2 . The system of  claim 1 , wherein the selected vibration comprises a selected level and/or frequency of vibration. 
     
     
         3 . The system of  claim 1 , wherein the selected vibration is sufficient to impart a lateral movement of a portion of the drill string of at least 5 mm. 
     
     
         4 . The system of  claim 3 , wherein the selected vibration comprises a frequency of from about 20 Kilohertz to about 60 Kilohertz. 
     
     
         5 . The system of  claim 1 , wherein the selected vibration is selected to reduce the pressure of a downhole cutting tool. 
     
     
         6 . The system of  claim 1 , further comprising:
 a downhole tool to couple to the drill string, wherein the selected vibration is selected to reduce operational friction between components of the downhole tool.   
     
     
         7 . The system of  claim 6 , further comprising:
 a controller to adjust the selected vibration to dislodge debris accumulated at the downhole tool.   
     
     
         8 . The system of  claim 1 , wherein the downhole sub comprises a portion of a downhole tool, the selected vibration being selectable to reduce operational friction of the downhole tool. 
     
     
         9 . The system of  claim 1 , wherein the vibration component comprises a flutter valve. 
     
     
         10 . The system of  claim 1 , wherein the vibration component comprises a motor. 
     
     
         11 . The system of  claim 1 , wherein the vibration component comprises a piezoelectric device. 
     
     
         12 . A method, comprising:
 introducing, via a vibration component mechanically coupled to a portion of a drill string, a selected vibration to the drill string to reduce operational friction of a downhole tool.   
     
     
         13 . The method of  claim 12 , further comprising:
 operating the downhole tool to cut a downhole object, wherein introducing the selected vibration increases cutting efficiency of the downhole tool.   
     
     
         14 . The method of  claim 12 , further comprising:
 operating the downhole tool, wherein introducing the selected vibration dislodges accumulated debris from the downhole tool.   
     
     
         15 . The method of  claim 12 , wherein introducing the selected vibration comprises actuating a flutter valve coupled to the drill string. 
     
     
         16 . The method of  claim 12 , wherein introducing the selected vibration comprises actuating a motor coupled to the drill string and to an eccentric weight. 
     
     
         17 . The method of  claim 12 , wherein introducing the selected vibration comprises actuating a piezoelectric device coupled to the drill string. 
     
     
         18 . The method of  claim 12 , wherein introducing the selected vibration comprises cycling hydraulic pressure via one or more valves. 
     
     
         19 . The method of  claim 12 , further comprising:
 monitoring relative positions of two downhole movable surfaces having a reduced relative movement range due to operational friction engagement; and   adjusting the selected vibration responsive to increase in the relative movement range of the two downhole movable surfaces.   
     
     
         20 . The method of  claim 12 , further comprising:
 controlling the selected vibration by adjusting the level or frequency of vibration.