Work extraction from downhole progressive cavity devices

Abstract

A progressive cavity device and method of use are provided, the progressive cavity device comprising a hollow stator having a rotor shaft positioned therein. The rotor shaft is provided with rotating motion drive connections at both ends thereof.

1 . A progressive cavity device comprising a hollow stator having a rotor shaft positioned therein, wherein the rotor shaft is provided with rotating motion drive connections at both ends thereof. 
     
     
         2 . The device as claimed in  claim 1 , wherein the drive connections are adapted to drive the rotor shaft. 
     
     
         3 . The device as claimed in  claim 1 , wherein the drive connections are adapted to extract drive from rotation of the rotor shaft. 
     
     
         4 . The device as claimed in  claim 1 , wherein at least one of the drive connections operates at a speed that is different to the rotation speed of the rotor shaft. 
     
     
         5 . The device as claimed in  claim 1 , wherein the drive connections couple to the rotation of the shaft. 
     
     
         6 . The device as claimed in  claim 5 , wherein the drive connections comprise a shaft connecting two universal joints. 
     
     
         7 . The device as claimed in  claim 5 , wherein the drive connections comprise a flexible shaft. 
     
     
         8 . The device as claimed in  claim 1 , wherein the drive connections couple to the nutation of the rotor shaft. 
     
     
         9 . The device as claimed in  claim 8 , wherein the drive connections comprise a non-nutating connection that imposes a nutation speed on the rotor shaft. 
     
     
         10 . The device as claimed in  claim 9 , wherein the drive connections comprise a disc mounted for rotation on a further shaft, the rotor shaft being connected eccentrically to the disc. 
     
     
         11 . The device as claimed in  claim 8 , wherein the drive connections comprise a planetary gear system, the rotor shaft being connected to a planet gear. 
     
     
         12 . The device as claimed in  claim 1 , configured to act as a motor or as a pump. 
     
     
         13 . The device as claimed in  claim 12 , wherein when configured as a motor, the rotor shaft is driven by pumping fluid through the hollow stator, and a rotating drive connection is taken from both ends of the hollow stator to power other devices. 
     
     
         14 . The device as claimed in  claim 13 , wherein the drive at one end is used to rotate a drill bit. 
     
     
         15 . The device as claimed in  claim 14 , wherein the drive at the other end is used to power a crushing device or an electricity generating device. 
     
     
         16 . The device as claimed in  claim 12 , wherein when configured as a pump, the rotor shaft is driven by a drive connection from a motor at one end and a rotating drive connection is taken from the other end of the rotor shaft to power other devices. 
     
     
         17 . The device as claimed in  claim 16 , wherein the other devices to be powered via the rotating drive connection comprise fluid air mixers, crushing devices, reaming or drilling devices and fluid mixing/shearing devices. 
     
     
         18 . A method for powering a crushing device in a wellbore, comprising the steps of:
 positioning a progressive cavity device in the wellbore, the progressive cavity device comprising a hollow stator having a rotor shaft positioned therein, wherein the rotor shaft is provided with rotating motion drive connections at both ends thereof;   driving the rotor shaft by pumping fluid through the hollow stator; and   powering a crushing device by means of a rotating drive connection taken from both ends of the hollow stator.