To the control room operator, data is a means to an end; it's necessary to keep the process running and productive. To management, data can be the difference between good or bad business decisions. If managers don't have ready access to operating data, they can't know what's happening in their facility, and they can't make the kind of maintenance decisions that result in higher productivity and greater profitability.
Unfortunately, in many organizations, getting accurate real-time data conveyed to all levels is difficult at best. Choosing the right field/end devices and an asset management system to ensure their ongoing accuracy and reliability is a good beginning. Even then, the flow of information from field instrumentation and other sources too often ends at the DCS, while passing secure operating data into the corporate environment is totally neglected.
Those who plan and implement automation systems often fail to consider the big picture; i.e., to look beyond the needs of the control system. Planners really ought to integrate the data acquired from intelligent field measurement devices with the means to convey timely information about operating conditions to those who need it most.
At Laricina Energy Ltd., data acquisition and management are essential elements in proving the validity of a unique process for extracting crude (bitumen) from a carbonate reservoir in the difficult environment of the Alberta oil sands region of Canada.
Laricina is a privately held company less than 10 years old. It is working to develop drilling technologies for removing heavy oil from vast carbonate reservoirs in northern Alberta that are estimated to contain more than 400 billion barrels of bitumen. If these reserves are proven to be commercially extractable, Canada could become the most oil-rich nation in the world, and Laricina investors would be duly rewarded.
Laricina's first pilot facility is the Saleski steam assisted gravity drain (SAGD) plant where a leading-edge project is underway to demonstrate the commercial viability of a new process involving the injection of steam and solvents into wells to recover oil. However, the random nature of the carbonate bed, which is neither uniform nor consistent, makes economical bitumen recovery a technological challenge. Those who need to know what's happening in the wells must have access to high quality, reliable data, since their analysis of the geological character of the reservoir and subsequent decisions are essential to the future of the company. This shared reservoir/process information is a critical factor in achieving Laricina's long-term goal of profitable commercial production of crude from this previously untapped source.
The system at Laricina Energy is based on Emerson Process Management's PlantWeb architecture and DeltaV field automation technology with regulatory and supervisory controls, which manage the entire plant from well pads and source water treatment to processing, steam and electrical generation, solvent injection/recovery and effluent. DeltaV also manages all discrete pump and motor controls, safety and ESD controls, and volume standardization according to American Gas Association (AGA) requirements.
The control architecture (Figure 1) incorporates a DeltaV system with about 1200 I/O, half of which are analog, and smart field transmitters or positioners (about 95% of which are HART or WirelessHART). These devices were chosen for accuracy, reliability and maintainability. The architecture also includes Emerson's AMS Suite: Intelligent Device Manager asset management software, a utility/SCADA network to gather additional field data and a data-bridge to the corporate Pi Historian in Calgary. The independent components of this system were integrated without difficulty.
The architecture is primarily e-net based, which allows online access—locally or remotely—to nearly all of the process (including end devices) for monitoring, troubleshooting and maintenance. The use of field laptops or handheld devices is unnecessary—a nice benefit in the harsh northern Alberta winter. This system provides close to an online synchronized instrument index for the HART analog devices with no manual intervention, and it is 100% accurate.
The designers wanted to avoid problems observed elsewhere, such as poor tagging. One of the biggest early challenges was establishing a consistent, plant-wide tagging methodology, ensuring reliable instrument recognition for configuration, accurate measurement and reliable documentation. Uniform tagging is also the key to the integration of three separate databases, which are discussed later. Tagging must be coordinated right from the start, and it can't be fixed later.