July 2021

Water management

Automation and oil field water management
Mark Patton / Hydrozonix

Cost reduction or optimization has always been a focus area for the oil field, and the unconventional space is testimony to that. Frac costs are dropping, efficiency is increasing, and this trend has continued where we are doing more with less. When it comes to water, we are seeing daily water volumes increase with efficiency gains from new frac methods. Automation is a natural transition to improve efficiency and reduce costs. Pretty simple, right?

Well, let’s take a closer look here. You see, produced water is unique. It is high-scaling, high-fouling water that carries with it abrasive proppant fines that cause extreme wear and erosion in some cases. All of these things are problematic for automation. We have seen cases where manufacturers have said they won’t warranty their devices in produced water. Then, there are the “ghosts in the machine,” and I’m not referring to dualism or the Police album, but the electrical gremlin effect. You see, produced water can also have high conductivity, and when you start running more and more electrical devices around your water, you start to see anomalies and data variances that defy logic.

So, automation requires a unique approach—improved insulation or isolation and improved grounding of devices. You will also need a routine calibration and field check. For example, many probes require monthly calibration, but in produced water, we opt for weekly calibrations or sometimes even more frequently when we see anomalous readings. This adds a bit of complexity to your automation strategy and the need to develop correlations with other parameters to know when results are drifting. We have found machined learning is a great tool here, where you can use predictive analysis to understand when devices need replacement or calibration or uncover relationships between parameters like chemical dose and ORP (Oxidation Reduction Potential). These correlations aren’t foolproof, but you will see over time a consistency to “when I add this chemical, I get this effect.” When you stop seeing this result, it’s time for a field visit and either replacing probes or other devices or cleaning and calibrating.

All too often, I see an approach where an application is taken from another industry and transferred to the oil field with the expectation that “if it worked somewhere else it will work in the oil field.” Most of the time, these don’t work as planned or must undergo numerous modifications. I’m not making the case that everything in the oil field should be custom-built, but you need to recognize the difference produced water makes and account for it.

Automation and ESG. Cost reduction, improved efficiency, and better data acquisition are all reasons people pursue automation. Another area often overlooked is improved ESG profile. You see, by reducing manned operations, you eliminate the truck trips associated with manned operations. Unfortunately, whether it’s the issues already mentioned from the effects of produced water management or reliability concerns of their automation program, many have declined eliminating manned operations or just reduced the manpower requirements. There is a significant opportunity being missed here. Many will challenge that there is too much risk in unmanning operations, but having co-developed four unmanned produced water recycling facilities that have been in operation for over a year, I can attest that the pursuit is worth it, and it can be safely accomplished.

The lessons here are all about checks and balances. Expect that produced water will be challenging. Expect there will be fouling, scaling, and erosion, and you will need to exceed manufacturers’ recommended maintenance schedules. Develop multiple ways to monitor the same parameters to provide the necessary quality assurance and control over your automation program. Once you have established a good comprehensive quality assurance and quality control program, you can now have confidence that you are developing an effective automation program.

Step by Step. This may take some time as you start evaluating your automation program, and you may want to take a phased approach. Start with a manned operation, and as you build confidence, slowly reduce manpower until you have developed the confidence to fully implement unmanned operations. Track the number of interactions between your manned operations and your system. This process will determine areas where your automation requires improvement.

Data acquisition. Developing a reliable quality assurance and control plan is critical in developing reliability in that data acquisition phase of your automation. From water volumes and flowrates to water quality parameters and Key Performance Indicators (KPIs), this is where the true value begins to materialize. A critical part of a management program is planning, evaluating produced water sources, quantities, and available volumes.

To successfully do this, you need reliability in your data acquisition. You need to know that flowmeters, probes, level indicators and transducers are all reliably operating and being calibrated and cleaned when, and if, necessary. You need to know that your program of checks and balances is working, that the quality assurance and control program is performing as designed. That your produced water quality is meeting KPIs. You have to commit to your program, but have a “belt and suspenders” approach, where you can cross-check your results with other parameters and with field visits and hand-held monitors.

This is how you develop accountability and the confidence to develop a truly automated program, which means unmanned. Now you have optimized cost reduction, improved efficiency and an improved ESG profile. This should be the goal of all automation programs for produced water management. Until next column, keep the water flowing.

About the Authors
Mark Patton
Mark Patton is president of Hydrozonix and has more than 30 years of experience developing water and waste treatment systems for the oil and gas industry. This includes design, permitting and operation of commercial and private treatment systems, both nationally and internationally. He has seven produced water patents and two patents pending. He earned his B.S. in chemical engineering from the University of Southern California (USC) in 1985.
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