Extending the range of a MEMS gyroscope using eccentric accelerometers
AssigneeBaker Hughes, A Ge Company, LLC
InventorsRobert A. Estes, Randell R. Riggs
Life of this patent
Estimating the term…
Abstract
A tool for use in a borehole penetrating a formation method and a method for using the tool is disclosed. The tool includes a gyroscope for obtaining a first measurement of a rotation rate of the apparatus and at least one accelerometer for obtaining a second measurement of the rotation rate of the apparatus. A processor generates an estimate of the rotation rate using at least one of the first measurement of rotation rate and the second measurement of rotation rate. The estimate of the rotation rate is sued to determine a rotational position of a formation parameter measurement obtained during rotation of the apparatus in the borehole.
Claims16
A method of measuring a rotational position of a sensor in a tool in a borehole penetrating a formation, comprising:
- using a gyroscope disposed on the tool to obtain a first measurement of a rotation rate of the tool;
- using at least one accelerometer disposed on the tool to obtain a second measurement of the rotation rate of the tool;
- and
- using a processor to:
- generate an estimate of the rotation rate of the tool using the first measurement of the rotation rate and the second measurement of the rotation rate, wherein the estimate of the rotation rate of the tool includes the first measurement of the rotation rate for those time periods during which the first measurement of the rotation rate is less than a threshold of the gyroscope and the second measurement of the rotation rate for those time periods during which the first measurement of the rotation rate is equal to or greater than the threshold, and
- use the estimate of the rotation rate to determine the rotational position of the sensor during rotation of the tool.
An apparatus for use in a borehole, comprising:
- a gyroscope for obtaining a first measurement of a rotation rate of the apparatus;
- at least one accelerometer for obtaining a second measurement of the rotation rate of the apparatus;
- and
- a processor configured to:
- generate an estimate of the rotation rate using the first measurement of the rotation rate and the second measurement of the rotation rate, wherein the estimate of the rotation rate includes the first measurement of the rotation rate for those time periods during which the first measurement of the rotation rate is less than a threshold of the gyroscope and the second measurement of the rotation rate for those time periods during which the first measurement of the rotation rate is equal to or greater than the threshold, and
- use the estimate of the rotation rate to determine a rotational position of the apparatus during rotation of the apparatus in the borehole.
Dependencies are inferred from the claim text.