摘要 |
In an MWD measurement system, the speed of rotation of a downhole turbine is measured by the interaction of a triaxial magnetometer in a sensor package and a permanent magnet attached to the turbine shaft. The triaxial magnetometer may be part of an existing MWD system for measuring borehole directional parameters. The magnet is a strong magnet mounted on the turbine shaft perpendicular to the axis of the turbine and the axis of the drill string.
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