Park position for a survey tool
AssigneeSchlumberger Technology Corporation
InventorsMakito Katayama, Julien Steimetz, Joffroy Dominique Daniel Urbain, Zainab Orooq
Life of this patent
Estimating the term…
Abstract
A gyroscope assembly is maintained in a park position during drilling activities. In the park position, a sensitive axis of a gyroscope in the gyroscope assembly is perpendicular or approximately perpendicular to a longitudinal axis of a downhole tool. Maintaining the park position during drilling activities reduces the drift bias caused by overloading the input signal of the gyroscope due to rotation of the downhole tool.
Claims20
A method for stabilizing a gyroscope assembly, comprising:
- rotating a gyroscope assembly to a park position of one or more predetermined park positions;
- rotating a downhole tool about a longitudinal axis, the downhole tool including the gyroscope assembly;
- and
- while rotating the downhole tool, maintaining the gyroscope assembly in the park position.
A gyroscope assembly housed in a downhole tool, comprising:
- a shell shaft;
- an indexable shell rotatable about the shell shaft;
- a gyroscope in the indexable shell;
- a processor;
- and
- computer-readable media including instructions which, when accessed by the processor, cause the processor to instruct a motor coupled to the gyroscope assembly to rotate the indexable shell to a park position of one or more predetermined park positions and remain in the park position while the downhole tool rotates.
A system for determining downhole direction, comprising:
- a housing having a longitudinal axis, the housing being rotatable about the longitudinal axis during downhole operations;
- and
- a gyroscope assembly, the gyroscope assembly including:
- an indexable shell;
- a gyroscope located in the shell;
- and
- a drive shaft rotatable about the longitudinal axis, the drive shaft including:
- an arm member coupled to the indexable shell;
- and
- one or more counter arms that mass balance the drive shaft.
Dependencies are inferred from the claim text.