Drilling assembly having a tilted or offset driveshaft
AssigneeHalliburton Energy Services, Inc.
InventorsJohn Keith Savage, Stephen Jones
Life of this patent
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Abstract
A drilling assembly includes a straight housing in which a mud motor assembly is mounted. The mud motor includes a rotor that rotates within a stator. The rotor has an axial centerline substantially parallel with the housing. A drivetrain is coupled between the rotor and a driveshaft. The driveshaft is coupled to a drill head. The driveshaft has a centerline that is non-coincident with (i.e., offset or angled) the axial centerline. The angle between the driveshaft centerline and the axial centerline may be fixed or variable. The angle may be variable in response to an axial force, imparted to the rotor, that is transferred to the driveshaft through the drivetrain. Additional apparatus, systems, and methods are disclosed.
Claims21
A drilling assembly, comprising:
- a motor assembly coupled to a housing and having an axial centerline substantially parallel with the housing;
- a drivetrain coupled to the motor assembly;
- and
- a driveshaft coupled between the drivetrain and a drill head, the driveshaft having a centerline fixed in a non-coincident orientation with the axial centerline.
A drilling system comprising:
- a downhole tool comprising:
- a substantially straight housing;
- a motor assembly coupled to the housing and having an axial centerline substantially parallel with the housing, the motor assembly comprising a rotor and a stator;
- a driveshaft coupled to the rotor, the driveshaft having a centerline at an angle with the axial centerline, wherein the angle is variable in response to an axial force applied to the rotor;
- and
- a drill head coupled to the driveshaft.
A method for drilling comprising:
- pumping drilling fluid down a drillstring;
- and
- adjusting a tilt of a driveshaft of the drillstring as a result of an axial force of the drilling fluid on a mud motor assembly.
Dependencies are inferred from the claim text.