Design of a Centrifugal Force-Based Speed Sensor for Downhole Turbodrills

Abstract EN

Turbodrill is an important type of drilling tool.

Rotating speed is a key parameter to measure and control the efficiency of a turbodrill.

Therefore, it is necessary to measure the rotating speed when a turbodrill is working under a well.

However, current speed measurement devices and sensors cannot meet the requirements of the on-site downhole conditions due to many factors, including inadequate sealing, signal interference, difficult installation, and theoretical limitations.

To break the aforementioned bottleneck, a new speed sensor used for turbodrills is designed based on the centrifugal force theory.

In more detail, the measurement of the speed is performed based on a functional relation between the rotating speed and the centrifugal force of the turbodrill.

Besides, the sensor was tested both in-lab and on-site.

The test results illustrate that the measurement error is within ±4%, which meets the practical on-site conditions.