Drilling assembly

Abstract

An assembly for use in drilling in earth borehole using a drill string including a drill bit comprising a first downhole motor having a rotor operatively connected to said drill bit, a second downhole motor distal said first downhole motor, said second downhole motor having a rotor with a passageway therethrough and a bypass valve operatively connected to the second downhole motor, the bypass valve having a first position permitting drilling fluid to flow through said passageway and a second position wherein drilling fluid is prevented from flowing through said passageway.

1 . An assembly for use in drilling an earth borehole employing a drill string, a drill bit comprising:
 a first downhole motor having an upper end and a lower end, a first rotor and a first stator, said lower end of said first downhole motor being proximal and operatively connected to said drill bit;   a second downhole motor having an upper end and a lower end, a second rotor and a second stator, said second rotor having a passageway therethrough and being distal said drill bit;   a bypass valve operatively connected to said upper end of said second downhole motor, said bypass valve being selectively movable from a first position wherein a drilling fluid can flow through said passageway in said second rotor to a second position wherein said drilling fluid is prevented from flowing through said passageway in said second rotor.   
   
   
       2 . The assembly of  claim 1 , further including an orienter subassembly connected between said first and second motors. 
   
   
       3 . The assembly of  claim 1 , wherein said bypass valve comprises a valve housing, a valve element carrier reciprocally movable in said valve housing and a valve element connected to said valve element carrier, said upper end of said second rotor having a valve seat engageable by said valve element whereby flow through said passageway can be selectively controlled by movement of said valve element into and out of engagement with said valve seat. 
   
   
       4 . The assembly of  claim 1 , further comprising a gear reduction subassembly connected to said second rotor. 
   
   
       5 . The assembly of  claim 1 , further including a logging tool disposed between said first and second motors. 
   
   
       6 . The assembly of  claim 1 , wherein said first motor has a bent housing.