Method of and apparatus for determining the path of a well bore under drilling conditions
AssigneeHalliburton Energy Services, Inc.
InventorsJohn Lionel Weston, Dieter Goetz, Gerard Hohner
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Abstract
Apparatus for determining the path of a well bore during drilling, comprises an inertial measurement unit (12) for providing data from which position, velocity and attitude can be derived, the measurement unit comprising a plurality of inertial sensors mounted on a platform assembly which is, in use, disposed within a drill string (6), and a drive unit (5) for rotating the platform assembly so as to control the rate of angular displacement of the platform assembly with respect to an Earth fixed reference frame.
Claims15
Apparatus for determining the path of a well bore during drilling, comprising:
- a drillstring disposed in the well bore, wherein said drillstring has a first rate of angular displacement about its longitudinal axis;
- a platform assembly disposed within said drill string, wherein said platform assembly is only rotatable about the longitudinal axis of the drill string;
- an inertial measurement unit comprising a plurality of inertial sensors mounted on said platform assembly and adapted to provide data from which position, velocity and attitude can be derived, and
- a drive unit for rotating the platform assembly about the longitudinal axis at a second rate of angular displacement so as to control the rate of angular displacement of the platform assembly with respect to only one axis of an Earth fixed reference frame.
A method for determining the path of a wellbore during drilling comprising:
- disposing an inertial measurement unit having accelerometers and gyroscopes mounted on a platform assembly disposed within a drill string rotating at a first angular displacement;
- rotating the platform assembly with a drive unit at a second angular displacement so as to control the rate of angular displacement of the platform with respect to only one axis of an Earth fixed reference frame;
- using the output signals of the gyroscopes to resolve output signals of accelerometers into the Earth fixed reference frame;
- integrating resolved output signals of the accelerometers once to provide information representative of velocity;
- integrating resolved output signals of the accelerometers twice to provide information representative of position;
- and
- generating estimates of inclination azimuth and tool face angles.
An apparatus for determining the path of a wellbore during drilling, comprising:
- a platform disposed within a drill string rotating about its longitudinal axis at a first angular velocity;
- a means for providing data from which position, velocity, and attitude can be derived, wherein said means for providing data is mounted to said platform;
- a means for rotating said platform at a second angular velocity in response to the rotation of the drill string so as to control the rate of angular displacement with respect to only one axis of an Earth fixed reference frame.
Dependencies are inferred from the claim text.