A major oil and natural gas company with more than 70 years' experience in natural gas exploration and production supplies over seven billion cubic metres of natural gas per year. It also imports, transports, stores and sells natural gas.
The challenge
Consumers need varying amounts of natural gas at different times. Seasonal, weekly and hourly fluctuations need to be met by the supplier. To help manage these demand fluctuations, pipeline companies often use abandoned gas mines and other underground cavities to hold small quantities of natural gas that they can quickly bring online when needed.
One example of this type of underground cavern is located in a small town in the north of Germany. In conjunction with a facility in an adjoining town, it supplies consumers around Hamburg. All of the storage facilities are state of the art and designed to meet applicable codes and regulations.
An automated process control system monitors and controls all of the operating procedures in the system, which is automatically switched off if values go above or below specified limits. Three artesian wells are used to monitor the tightness of the underground storage facilities: an increase in pressure beyond a specified value indicates that there is a fault. In the past, these pressures had to be read manually requiring frequent trips to the remote sites by the company’s technicians.
Solution
The company installed two unidirectional radio paths between the remote storage facilities and the central control station. Phoenix Contact’s Trusted Wireless I/O modules transmit the analog measured values over distances of approximately 300 metres.
Because of the distances involved, one of the locations was without power. It was integrated into the system using a Phoenix Contact Solar Interface System (SIS), which continuously powers the sensor and unidirectional radio module allowing information to be transmitted back to the control centre as required.
Since this was a European installation, the power transmission for Trusted Wireless I/O was limited by government regulations to 10 mW. To overcome obstructions and distance challenges, a 19 dB parabolic panel antenna was installed at the receiver end, the high gain creating a successful link between transmitter and receiver.
Summary and results
* The pressure of underground natural gas storage containers needed to be monitored to detect leaks.
* Trusted Wireless I/O transceiver modules were used to transmit data from remote well sites to the control centre.
* At the remote location, solar panels were used as a power supply enabling radio use without grid connection.
* The customer saved money and time to the remote locations to manually read the pressure levels.
* Leaks are identified quickly thanks to continuous monitoring.
For more information contact Anike Visser, Phoenix Contact, +27 (0)11 801 8200, [email protected], www.phoenixcontact.co.za
| Tel: | +27 11 801 8200 |
| Email: | [email protected] |
| www: | www.phoenixcontact.co.za |
| Articles: | More information and articles about Phoenix Contact |
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