Dart Oil and Gas has approximately 500 remote methane well sites in the Cherokee basin of Kansas. The company uses electronic flow computers to monitor and record gas flow data at well, compressor and pipeline monitoring sites. These flow computers are equipped with 900-MHz spread-spectrum radios, enabling them to communicate data back to a central location.
The problem that Dart faced was its inability to make production data from its methane wells available to field personnel. All of the field data was consolidated at the main office and couldn't be accessed remotely, forcing a physical trip back to headquarters from the field to obtain data.
Dennis Brown, senior measurement engineer at Dart, says they designed the data acquisition system from the beginning for remote access. "Our goal was to use mobile devices to access the data in real time," says Brown. "This would give us the flexibility to create new data reports as the need arose and not be at the mercy of another company to manage the data through standardized reports."
To accomplish this, Dart used an OPC server to poll the flow computers and created a temporary database available for access, using OPC Systems.net and other tools provided by Open Automation Software. OPC Web HMI is used to create Ajax web pages that display real-time data accessible by any remote device with a browser. OPC Database is used to log data to an SQL server for trending and analysis. OPC Excel is used to access data in a spreadsheet format, enabling use of Excel's functions and macros.
Dart also uses Win-911 alarm software from Specter Instruments for voice call-out and reporting, and for text messaging to field personnel. Field personnel without smart phones can call in and receive voice reports about existing conditions after receiving alarm notifications, allowing very rapid troubleshooting of problems before they reach the site.
The OPC server, OPC Systems.net and Win-911 are running on the same dedicated server using a Windows Server 2003 operating system with a modem connected to the USB port for voice call-out. For local access to field data, Dart uses the Excel module from OPC Systems.net to display the data on desktop computers in spreadsheets for individual office users.
"OPC Systems.net has allowed us to create a web-based HMI using MS Visual Web Developer in a relatively short span of time with little prior knowledge of Visual Basic programming," says Brown. "Customer support from Open Automation Software has been great. We had only one issue that needed to be addressed during the installation, and a fix was sent to me in a matter of minutes. The software has functioned flawlessly for the two years it has been in service."