Drill string with modular motor units
AssigneeSchlumberger Technology Corporation
InventorGuy J. Rushton
Life of this patent
Estimating the term…
Abstract
A turbine for use in a downhole drill string including an elongated casing defining an interior and a plurality of motor units in the interior. Each motor unit has a rotor and a stator. A torque transmission couplings connects each of the plurality of motor units to the drill string. The torque transmission couplings having flexible linkages. As a result, the power section has tight tolerances for the clearance at the tips of the rotors because the motor units are relatively stiff. The flexing normally obtained by bending the rotor shaft is accomplished and absorbed in the flexible linkages.
Claims28
A turbine for use in a downhole drill string comprising:
- a plurality of elongated casings, each casing defining an interior;
- a motor unit in each interior having a rotor and a stator;
- and
- a torque transmission coupling with flexible linkages for each motor unit.
A turbine for use in a downhole drill string comprising:
- an elongated tubular casing defining an interior and an axial fixing groove;
- at least two motor units in the interior, each motor unit having a rotor and a stator, wherein the motor units are keyed to the axial fixing groove;
- a bearing in each motor unit for supporting movement of the rotor;
- a membrane coupled to each bearing for creating a pressurized oil reservoir around each bearing for lubrication;
- and
- a torque transmission coupling with flexible linkages connecting the motor units to the downhole drill string.
A method for downhole drilling comprising the steps of:
- providing two turbine motor units for use in a downhole drill string, each motor unit having a rotor and a stator;
- surrounding the two turbine motor units with an elongated tubular casing;
- supporting movement of each rotor with a bearing;
- surrounding each bearing with a membrane, which pressurizes magneto-rheological fluid therein;
- and
- coupling the two motor units together with flexible linkages.
A turbine for use in a downhole drill string comprising:
- an elongated casing defining an interior;
- a plurality of motor units in the interior, each motor unit being attached to the elongated casing;
- and
- a torque transmission coupling between each of the plurality of motor units.
A turbine as recited in claim 26, wherein each motor unit has a rotor and a stator.
A turbine as recited in claim 26, further comprising flexible linkages connecting the plurality of motor units.
A turbine as recited in claim 26, wherein the motor units are attached to the casing by a coupling selected from the group consisting of an axial groove with mating protrusion, an interference fit, adhesive, a setscrew and combinations thereof.
Dependencies are inferred from the claim text.