In an industry where every spill carries a hefty price tag, Point Energy Partners (PEP) found that the manual and low-tech systems at their saltwater disposal (SWD) sites were a significant problem. SWD sites are where the byproduct water from oil and gas production is managed and disposed of. These low-tech systems for SWD level management posed several operational challenges, the worst being the environmental impact and financial costs of overflow spills.
PEP specialises in acquiring and developing onshore US oil and gas properties, with a current focus on the Delaware Basin. The company is dedicated to the sustainable development of oil and gas resources across the US. PEP also operates a substantial water recycling programme.
The challenge: high tech and low price
The SWD sites, where water laden with salts, hydrocarbons and industrial compounds is managed and disposed of, required immediate attention. Manual, onsite checks of their flow measurement systems resulted in inaccurate measurements and unreliable information. In addition, the existing water management system at these sites was heavily dependent on hydrostatic head level switches, technology that had become obsolete and unreliable.
Beyond that, the level switches were part of an antiquated system of control that attempted to maintain safe tank levels by toggling transfer pumps based solely on the current switch status or an onsite manual override. This outdated control methodology left no room for the possibility of remote control or oversight.
These existing operational sites did not have a big budget for upgrades, so most control solutions on the market just wouldn’t fit the bill. But after an internal study determined each overflow spill cost the firm roughly$200 000, automation engineer, Scott Adams knew the status quo would not suffice.
Head level sensing vs radar level sensing
The next generation solution should utilise radar level sensing, a superior solution compared to hydrostatic head level sensing. Unlike hydrostatic sensors, which measure pressure exerted by a liquid column, radar sensors utilise microwave pulses to determine liquid levels. This non-contact method ensures no direct interaction with the liquid, making it ideal for corrosive substances, like the water being stored at SWD sites. Radar sensors are unaffected by changes in liquid density, temperature or pressure, and provide better precision and durability in challenging conditions.
Visibility
The lack of visibility into the operations at the SWD sites, coupled with an over-reliance on manual checks and operations, underscored the urgent need for a modern, automated solution. A recent corporate initiative led PEP to use Inductive Automation’s Ignition software as a scada platform for its collective sites. The burgeoning IIoT infrastructure would use MQTT Sparkplug B as a means for getting live, reliable data on its operations into its new scada platform. And Ignition’s Perspective web-based HMI would soon make remote monitoring a reality.
Keeping costs under control
PEP faced significant financial constraints, as the budget for improvements on existing sites was tight. The company needed to ensure that any investment made would pay itself back in efficiency, reliability and spill prevention. They explored various PLC solutions on the market, but price tags were high, and many of the manufacturers required expensive software licenses and support contracts.
Blending brownfield with greenfield
When PEP started down its IIoT discovery journey, it was clear that MQTT with Sparkplug B − lightweight, efficient and reliable − was the way to go. But there were also cases where legacy support was needed, like brownfield installations where Modbus/TCP was highly utilised. Adams also needed an I/O platform that was flexible enough to simply turn on a contactor to run a pump, read an analogue signal from modern radar level sensors, or calculate flow from a pulse input generated by a turbine flowmeter.
The solution: groov RIO
“We were looking for I/O that would fit with our new scada, and Opto 22 hardware kept coming up for MQTT and Ignition,” Adams said. “We planned to use Ignition’s Historian, Alarming, and Perspective visualisation to keep tabs on our SWD sites from anywhere in the world.”
So PEP turned to Opto 22’s groov RIO for a transformative solution. The modern communication methodologies onboard, namely MQTT with Sparkplug B payloads, would allow the groov RIOs to reliably transmit real-time tank levels, flow rates and pump operational states into PEP’s Ignition SCADA. They could seamlessly and efficiently move data between their field operations and Ignition SCADA software.
Flexible I/O
The multi-signal, multifunction nature of Opto 22’s groov RIO’s I/O gave PEP the flexibility to adapt these edge devices for a number of their applications. The relay outputs could be used to fire pump contactors on and off based on more accurate level readings, which were now being fed from radar transmitters connected directly into RIO’s analogue input channels.
Utilising groov RIO’s flexible I/O, along with the recent addition of a CODESYS runtime engine, allowed them to implement radar level transmitters in the tanks and automatic pump control. PEP had experimented with groov devices in the past, but the unique aspect of this setup was the utilisation of the CODESYS runtime engine, a feature added in groov RIO firmware 3.5. This addition levelled up the capabilities of groov RIO, providing a cost-effective and powerful automation solution.
Control at the right price
At around $1000, Scott Adams described RIO as the ‘Goldilocks solution’ rather than a $10 000 panel with unnecessary extras, or a $100 PLC lacking the I/O and modern communications needed for their IIoT architecture.
Modern, yet supportive of our legacy
The cherry on top was groov RIO’s support for legacy devices. PEP had numerous pressure transmitters across its SWD sites that used legacy Modbus/TCP communications. Using groov RIO as a Modbus master allowed PEP to collect existing data that was once trapped in the field and add it to the new collection being amassed in their data historian.
Technical implementation
Implementing groov RIO into PEP’s existing infrastructure was a smooth and straightforward process, highlighting the system’s user-friendly nature. Technicians found the system easy to work with, thanks to an intuitive interface and comprehensive training resources available on Opto 22’s website.
Rajant wireless mesh
One of the pivotal components in this implementation was the integration of a wireless mesh radio network provided by Rajant, a leader in industrial wireless mesh network solutions. Rajant’s technology ensured a robust and reliable communication network, vital for the remote monitoring and control capabilities required at the SWD sites. Combine that with an industrial-grade device like groov RIO with IT-friendly networking tools, and seamless data transmission is a reality, even in challenging and remote environments.
Software stack
Using CODESYS for automated pump control and tank level management was just a part of this solution. PEP is also using Node-RED software running onboard their RIO, which allows them to move data from physical I/O points, CODESYS tags, and various Modbus/TCP sensors into OptoMMP registers, which are then published on change to their Ignition-based MQTT broker.
Results and Impact
The implementation of groov RIO at the SWD sites has resulted in a paradigm shift for PEP. Automating water level monitoring and pump operation has not only made the jobs of field operators easier, but has also resulted in significant cost savings, most importantly, by preventing potential spills.
The field operators, who previously had to check tank levels manually and ensure the proper functioning of head switches, now enjoy a more streamlined and efficient workflow.The systems can be fully monitored remotely, and tank level setpoints can be securely adjusted from anywhere in the world.
The enhanced data reliability and real-time monitoring have also shown PEP the value of further automation across other sites. PEP management, originally hesitant to make the investment in automation at SWD sites, have shifted their approach to automation and technology, opening doors to new possibilities and applications across their portfolio. The significant improvements in efficiency, reliability, and environmental safety have showcased the transformative power of automation, proving that with the right technology, safe and sustainable energy development is not just a goal, but a reality.
The rugged groov product line from Opto 22 is distributed and supported in South Africa by Opto Africa Automation.
For more information contact Prashanth Gokaran, Opto Africa Automation,
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