A comparative study of multichannel and single channel accelerometer sensors for communication in oil wells

Transmission of information from the downhole of oil wells to the drilling platform on the surface is a key part of drilling operations for oil exploration and extraction. Important data such as temperature and pressure collected by sensors near the drill bit are needed to be modulated on acoustic signals, to travel thru drill strings. On the surface, accelerometers which convert acoustic signals to electric signals can be used to receive and demodulate the data. In this paper, we study the performance of multichannel and single channel accelerometers used as uphole communication receivers. Using experimental results from a drill string communication testbed, we show that one tri-axial accelerometer can provide nearly uncorrelated signals, compared to two single channel accelerometers. Having uncorrelated signals at the uphole receiver provides diversity which in turn can result in an increase in the communication system performance.