The Evolution and Potential of Networked Pipe

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Technology Update The need for “next-generation” technology for improved data transmission up the hole in drilling operations has been acknowledged for more than 2 decades. The term “next generation” typically implied a quantum leap in transmission speed from that available, by means of current state-of-art telemetry. That need is now filled by networked drillpipe (Figs. 1 and 2). Development of the technology began in 1997. Initial R&D addressed two problems, the growing need for a high-rate data-communications system that would allow high-resolution downhole drilling information to facilitate informed drilling decisions in real time and the attendant need to bring data-transmission rates to up to five orders of magnitude from mud-pulse telemetry’s approximate high of 10 bits per second. Evolution of Networked Pipe Networked pipe had its genesis in a program undertaken by Novatek in 1997 to develop a mud-actuated hammer and a unique hammer bit. The company proposed to develop a set of complementary technologies integrated into the mud hammer that would enable various functionalities of the bit, including: 1) downhole bit rotation, 2) sensing and control, 3) data transmission, and 4) directional-drilling capability. In the case of data transmission, the company concluded that a much higher data bandwidth was needed by the oil and gas industry than could be delivered by either existing mud-pulse telemetry or a new hammer acoustic-telemetry system. This was particularly true when considering the need for real-time data to support seismic while drilling (SWD), another possible offshoot of the hammer development. With this conclusion in mind, other acoustic sources with higher frequency ranges than the hammer were investigated. Substantial project focus was directed to this area of R&D, as it was deemed to be a critical enabling technology for the rest of the drilling system under development. Initial development focused on the use of acoustic transmissions to carry high-frequency data through a single length of standard drillpipe. Data-rate limitations led to the abandonment of the concept and to the investigation of wired pipe that transmitted data across the tool joints using high-frequency acoustic transducers. However, the need for electric power and electronic support for each transducer, and the need for timing of the threaded connections when made up, led to the abandonment of that approach also. The company then directed its focus to fundamental work performed with a high-efficiency inductive-coupling sys-tem that looked promising. That technology resulted in networked drillpipe.