February 2010 Vol. 237 No. 2
Features
Cockrell Ranch Waterflood: What Wireless Network?
The Cockrell Ranch Waterflood project is an ambitious enhanced oil recovery project located in the Texas panhandle. Cano Petroleum uses state-of-the-art technology and methods to recover oil from wells that would have once been considered ‘tapped.’
The waterflooding process uses pressurized water to move through the formation, driving raw crude oil out of the ground from wells.
Boss Automation of Spearman, TX was hired to design and install the discrete automation platform and a control network to monitor pressure and flow of this water into the wells. With their experience in automation, control and process optimization, the project evolved into the design and implementation of a new, fully automated, self-monitored SCADA system that is also adaptable for the pipeline industry. The system was designed to gather, assemble, and transmit data from the wells and injectors and ultimately bring it back to a Master Station. This allowed the daily operation of the field to be monitored and controlled from these sites, and allowing the collected data to be used to produce detailed production models.
Considerations for the system included: reliability, maintainability, ease of use, as well as the ability to obtain local support. With the aid of Rexel, the local Allen-Bradley distributor, Boss Automation decided on a combination of Allen-Bradley hardware, Rockwell Automation software, and ProSoft Technology wireless communication solutions.
The SCADA system consists of one ControlLogix at a Main Master Station tied to four ControlLogix slave sub-stations and more than a hundred custom-built Remote Terminal Units (RTUs), each comprised of an Allen-Bradley MicroLogix 1100 Programmable Logic Controller (PLC) and a ProSoft Industrial Hotspot radio. The Main Master Station and four substations represent the backbone network of the project. Each of the four substations acts as a Master for its respective sub-network. All communication from the wells and injectors to the substations, and from the substations to the Main Master Station, is handled wirelessly using ProSoft’s Industrial Hotspot solution.
Paul Brooks, Business Development Manager, Networks Portfolio for Rockwell, noted, “For this application, ProSoft’s wireless technology provides the backbone communication for the integration of this system creating a reliable, industrial and transparent network which allows Cano Petroleum to successfully monitor their process data remotely.”
At the Main Master Station, a Human Machine Interface (HMI) application for the system was developed using Rockwell’s RSView 32 software. The graphical interface screens have proven to be user-friendly, and the Messenger Pro feature provides the operators with detailed information about alarm conditions in human voice, by automatically calling the cell phone of the person on call. ProSoft’s RadioLinx OPC Server is used on the remote access computer to monitor the status of the radio network.
An impressive amount of data – more than 3,500 discrete Input/Output as well as 1,000 analog points — is gathered and moved across the wireless network at about 11 Mbps to the Main Master Station where it is then assembled into data log models, then interfaced by Cano’s own proprietary modeling software.
Rexel was instrumental in providing logistical and technical support for the project. With respect to this large-scale wireless network, ProSoft provided engineering support throughout the project.
The overall network covered 12 square miles with the longest link being two miles and a bulk of the radios were positioned in an area of about three square miles which presented a concern. “In a radio network of this size it is imperative that care be taken in setting up the PLC messaging,” said Patrick Haga, ProSoft Wireless Engineer. “If all radios are trying to communicate at the same time, you can quickly swamp your bandwidth with RF collisions and retries.”
He added, “This in mind, we discussed the need to create a polling style network rather than having all the radios trying to communicate at the same time.”
Chris Deakin of Boss Automation said, “The process is incredibly reliable, consistent and makes for an essentially self-managed site. From the main SCADA monitoring station, the operators are able to see virtual diagrams of the wells and what is going on within them, as well as all the data collected by the RTUs and control units.”
The project went live in 2008 and has had near zero downtime. “The wireless network works so seamlessly and reliably that it is virtually transparent to the user,” Deakin said. “When all was said and done I asked the customer how they liked the wireless network. Their response: what wireless network?”
Harry Forbes of ARC Advisory Group noted, “The Cockrell Ranch Waterflood project illustrates three important points about industrial wireless. First, wireless is indispensible for this kind of SCADA project to be cost-effective. Second, end users need to select hardened, industrial, field-proven products to provide a lifelong, reliable wireless solution. Third, a well-designed wireless network can deliver data in a SCADA system with very high reliability, in fact so high that end users forget about it.”
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