United Kingdom

Vol. 226 No. 4

Downhole vibration monitoring system with live data transmission and analysis

A new Vibration Analysis Board (VAB) was recently introduced by AnTech Ltd. The system measures the vibration of drilling tools downhole while drilling. The VAB is the first of its kind to offer drilling engineers the opportunity to analyze live data and transmit a full set of measurements to the surface as drilling is taking place. In addition to torsional vibration, data is monitored over three dimensions. By making this possible, risk assessment is efficiently carried out on the drilling tool, allowing appropriate remedial action to be taken. Early detection of problems could result in significant reduction in damage to drilling tools.

Downhole vibration analysis tool with sample output.

To offer the full range of measurements relevant to vibration, the four-channel VAB was developed with several innovative features. It uses a Controller Area Network (CAN) bus, flexible analysis range settings in real time, up to four high-precision accelerometers and a Texas Instruments digital signal processor to carry out accurate measurements. All of this allows for measurement of the x, y and z motions, as well as monitoring torsional vibration as a completely separate motion. Once this data is gathered, it is relayed to the surface via the CAN bus communication interface.

Vibrations up to 250 g, from 1 Hz to 2.5 KHz are measured. In addition, the system performs a Fourier analysis of the data downhole, and condenses the data in preparation for sending to the surface. Also, to further reduce traffic on the communications bus, the uphole control software allows the user to specify the range and resolution of the results, as well as how often results are to be gathered and transmitted.

Although the VAB was originally designed for the COLT (AnTech’s electrically controlled CT-drilling BHA), it can be easily incorporated to operate in conjunction with other systems, including memory tools, perforating strings and pipe-in-pipe expansion systems.