The goal of this project is to investigate the use of a natural gas pipeline as a means of transmitting signals by either of two methods: as a waveguide for microwaves or commercial wireless modems, or by directly introducing a signal into the pipe (treating the pipe as a leaky feeder or a multi-ground neutral). Using the pipeline as a carrier for communication signals would facilitate the use of pipeline maintenance and leak detection tools such as smart pigs, remote sensors and pipe explorer autonomous vehicles.
University of Missouri-Rolla (UMR) – project management and research product
Rolla, Missouri 65401
The existing U.S. natural gas pipeline transmission network is comprised of approximately 90 pipeline systems that make up the onshore mainline interstate gas pipeline network. Another 60+ pipeline systems make up the gathering lines. The majority of these natural gas pipeline systems are large diameter (>30”) steel pipelines with welded joints. Gathering lines are similar, although these lines typically are smaller in diameter.
Gas movement through these pipeline systems is accomplished by adding compression stations approximately every 50 to 100 miles. In addition, safety shut-in valves may be included at critical places in a pipeline, particularly near high consequence areas. Pipeline pressures and flows are typically monitored and/or controlled with supervisory control and data acquisition (SCADA) systems using remote terminal units (RTU), programmable logic controllers (PLCs), and either satellite, microwave, or telephone communication links. These controls are subject to interruption from loss of communication and are subject to interference by knowledgeable third party intruders.
Reliable communications links from one end of a pipeline to the other end are vital for effective pipeline monitoring and control. This project seeks to investigate using the pipe as a waveguide and treating the pipe as the signal conductor. Both of these techniques are anticipated to be more reliable and less expensive than existing methods of remote communication. In addition, these methods may be retrofitted into existing pipeline infrastructure.
This technology, if fully and successfully developed, offers the potential to enhance the capability to provide effective pipeline monitoring and control. This will help to increase the security of the infrastructure from intentional or accidental damage and to enhance the reliability of gas delivery from the nation's infrastructure by quickly and effectively communicating pipeline information to the persons who need it. In addition, the system offers potential as a communications medium for un-tethered inspection technologies used for evaluation of pipeline condition. By increasing the efficiency and range of these inspection technologies the overall integrity of the pipeline system is improved through more effective monitoring.
Both methods were initially tested on a small pipeline loop at the University of Missouri-Rolla. The pipeline as a waveguide effectively transmitted signals of a few GHz. A test with commercial 802.11b modems was also successful. When using the pipeline as a conductor, the UMR pipeline showed little attenuation.
Both methods were tested with a much longer pipeline at Battelle. The pipeline as a waveguide effectively transmitted signals of around one GHz, a lower frequency than for the UMR pipeline. Tests with commercial 802.11b modems were also successful. When using the pipeline as a conductor, the Battelle pipeline could transmit signals in the range of 10 to 100 kHz. From the communication protocol simulations, Optimized Link State Routing (OLSR) performed the best for a large scale network of pipeline sensors. While the data delivery rate was not quite as high as one would hope, especially at higher node speeds, delivery rate probably could be increased with a change of the OLSR parameters to allow more frequent neighbor sensing and multipoint relay set broadcast. With small networks, Dynamic Source Routing (DSR) would probably be a better choice because of its high data delivery rate. The experimental results presented in this report indicate that both methods of transmitting signals are feasible. A pipeline can act as a waveguide to frequencies in the few GHz range, allowing the use of commercially-available radio modems. A pipeline can also support direct signal injection of a signal with a frequency of a few kHz. The next step in this work is to build hardware to test the feasibility to transmit a few miles.
Project work has been completed. Final project results will be provided in the project final report due by early Spring 2005. Potential follow on work to that developed under this project includes investigation of using the developed techniques as potential wireless communication techniques for use with un-tethered robotic inspection platforms.
Final Report - Pipelines as Communication Network Links [PDF-1944KB]