With new technologies making it more cost-effective and easier to integrate, the oil and gas industry is increasingly using SCADA to help improve and link operations, according to a report from ARC Advisory Group. Canadian Natural Resources Ltd. (CNRL) is taking advantage of improved capabilities and functionalities to better manage a diversified set of assets in North America, the North Sea and Offshore Africa.
Headquartered in Calgary, Alberta, CNRL is the largest independent crude oil and natural gas producer in Canada. CNRL needed a better way to manage the process control and monitoring of its 300 gathering stations, 800 compressor stations and 150 gas processing facilities, so set out to replace its FactoryLink SCADA systems. Siemens announced in mid-2007 that it would classify FactoryLink as a mature product, and cut off general market availability at the end of last year.
Upgrading to Arc Informatique’s pcVue SCADA and FrontVue solutions, CNRL aimed to centralize and integrate as many of its automation systems as possible onto pcVue, according to Kurtis Jackson, CNRL’s SCADA specialist who spearheaded the project. In addition, CNRL wanted to leverage pcVue’s ability to support multi-station architectures for networking, and is running Modbus Roc, Roc Talk and BSAP.
CNRL—with GE and Allen-Bradley PLCs, and Fisher and Bristol Babcock RTUs as the major brands used throughout production—began migrating its FactoryLink SCADA to pcVue using the Smart Generator, which automatically converts a very high proportion of the existing applications to pcVue while maximizing compatibility and security. “For most of our SCADA applications we were upgrading, 60-80 percent of our FactoryLink applications converted to pcVue with ease,” Jackson says. “This saved us a tremendous amount of time with not having to reconfigure the entire applications, and it meant that we did not have to retrain our users.”
CNRL has implemented eight pcVue servers with remote client access and expects to deploy about 40 pcVue SCADA systems within the next two years. Production reports are run daily, Jackson says, using real-time and historical trending to provide the data needed to meet production goals and sales contracts.
Value-added reseller CTH Systems helped to configure and facilitate the migration to pcVue. Using Smart Generator, the engineers were able to convert all of the graphical elements (mimics, symbols and templates), local and shared libraries (symbols, pictures), all sets of variables for the application (including variable tables, alarm configurations and histories) and the database without any rework. It also converts the TCP/IP communication objects and their links. “We were really happy with how easy it was to transfer all of our applications to pcVue in a very easy, straightforward manner,” Jackson says.
In addition, CNRL uses CTH Systems’ IM-SCADA, a multiprotocol measurement and communication software. It allows the wells that are equipped with different automation devices, such as RTUs or pump on/off controllers, to talk over a single radio channel in order to bring the data back to pcVue SCADA. CTH Systems supported CNRL to implement automatic and remote readings of gas compositions from the well, upload the corrected gas compositions to each well, and eliminate variances between the well meter and the IM-SCADA database. “We couldn’t be happier with how robust and effective the IM-SCADA driver works for us,” Jackson says. “It helps maximize operational efficiency.” It minimizes the need to physically go to the well sites to download or upload the gas compositions, he adds.
CNRL has 178 host servers along with 600 remote clients, monitoring some 5,000-6,000 data points per host. The eight pcVue stations supervise 50-400 wells and one to three facilities per host, depending on location or region. “This translates to thousands of tags and alarm parameters that are being monitored and acknowledged daily,” Jackson says. As the oil flows out of the well, it passes through a pipe arrangement, which is connected to flow lines that bring the oil and gas to gathering stations where sediment, gas, salt water and oil are separated. pcVue is also monitoring the gathering stations.
The pcVue SCADA collects such I/Os from PLCs and RTUs used in production fields and gathering stations such as gas/oil pressures, ESD, pump start/stop, remote/local pump control, pump speed, pump run/stop, motor-operated valves and motor-operated valve shutdown, choke setpoints/positions,temperature, emergency shutdown and fire alarms etc. “One of the most important factors in our industry is safety,” Jackson says. “At every stage of the process, pcVue monitors our mission-critical operations and maintains all of our safety measures to prevent fires, explosions and ecological disasters.”
Characterized by remote and widespread operations, CNRL wanted to have each automated activity—whether in drilling/production, distribution, transportation or refining—supervised from several of its control centers. A solid and securely designed SCADA system must be able to control such critical factors as flooding, leakage, fire, ESD, oil and gas flow rate and accumulated flow, line pressure, wellhead pressure, pump status, tank level, and gathering station equipment status, among others. Because of the nature of the product, which must be transported from the well to final consumer, and the potential adverse environmental effects of oil/petroleum accidents, SCADA systems are a necessity. “We wanted to leverage SCADA features and benefits that give us the ability to reliably gather more data and achieve more control,” Jackson says.
