Drilling systems automation requires a downhole digital backbone for closed-loop control, as do many other real-time drilling, completion and production operations. The absence of a reliable, high data bandwidth, bi-directional communication method between surface and downhole is a barrier to digitalization and automation of the oil field. This paper describes the development and successful drilling field trial of a micro-repeater wired pipe – effectively "smart pipe" – that removes this barrier.
The developed system uses battery-powered micro-repeaters (a fail-safe signal booster) placed within the box of each tubular and fully encapsulated dual RF-resonant antennas to transmit data between tubulars. The current system delivers 1-Mbps backbone data rate with a maximum payload of 720 kbps, and with a very low latency of 15 μsec/km, making it ideal for control-loop applications. The system design focusses on reliability: failure of multiple components will not affect telemetry. The prototype system has been rigorously field tested during drilling in Oklahoma.
Testing occurred on a drilling rig in Beggs, Oklahoma. The first trial (2016) covered drilling operations, the second (2017) covered controlling downhole technology; both were successful. The drilling trial demonstrated fitting the system to pipe with conventional API connections, standard rig-floor pipe handling, reliable wireless transmission between surface receivers and wired pipe network, the use of multiple along-string measurements of temperature and vibration, and simulated component failure. Of particular note was the surface system: it is wireless and no modification to the drilling rig was required.
Conventional tubulars can be refit with the system, which removes a barrier to the use of wired pipe for automation and LWD/MWD measurements in lower cost onshore operations. There is a benefit for drilling operations: all pipe joints contain a micro-repeater and are addressable for "smart pipe" applications such as an electronic pipe tally, and pipe condition monitoring. Drilling operations are the first users of the system, but it serves other operations, for example tubing conveyed wireline operations. The smart wired pipe concept is truly innovative. It enables drilling systems automation and logging-while-drilling applications, such as seismic-while-drilling with along-string sensors, by providing a fully open acquisition and control platform to the industry.