A Better Way to Manage Produced Water
Crude oil isn’t the only element extracted in the oilfield. Naturally occurring water – or “produced water” – is an ever-present byproduct that must be managed in an environmentally compliant way.
Water is also vital to drilling and fracking.
“Water is a primary ingredient in ‘drilling mud,’ which is used to equalize pressure and stabilize exposed rocks during the well-drilling process,” said John Clay, CEO, Endpoint Industrial Controls. “Of course, water is also used to create fractures, which allows hydrocarbons to more easily flow.”
Highly brackish, untreated produced water is unfit for drilling and fracking operations. And until relatively recently, most was piped to highly regulated salt water disposal (SWD) wells. Oil companies relied on other water sources for production needs.
But thanks to expanding water treatment capabilities, produced water is increasingly recycled. One produced water midstream company is leading the way. And they called on Endpoint for an agile control system to match their innovative water treatment and recycling technologies.
Endpoint Industrial Controls delivers turnkey automation and control solutions for a wide range of industries – from oil and gas to renewables to manufacturing. Headquartered in Loveland, Colorado, the company is part of the Rockwell Automation® PartnerNetwork™ program.
System Complexity and Volume Requirements
Established in 2013, Endpoint’s customer operates more than a dozen geographically dispersed water recycling facilities and associated pipelines throughout the oil-rich Permian Basin in West Texas and New Mexico. In total, their facilities manage 1.2 million barrels of produced water per day.
“The company has both permanent facilities and mobile units,” Clay said. “The mobile systems might be set up for a couple of months or a few years – and then rotated to another site.”
Dissolved air flotation (DAF) technology is the centerpiece of the system. The influent water stream is pumped into the DAF vessel, where various chemicals including coagulants, flocculants and oxidants treat the water. A pressurized airstream is introduced, creating micro-bubbles in the solution.
Lighter particles in the water attach to the bubbles and rise to the surface. Heavier particles sink to the bottom. The particles – mostly hydrocarbons, chemicals and solids – are removed as sludge. The treated effluent is pumped to a clear water well where it is tested for clarity, stored – and pumped to a fracking operation for reuse.
From a control standpoint, the system presents two critical challenges.
“First, these sites aren’t all the same – and you might be dealing with one DAF or multiple units,” Clay explained. “Second, the system must be responsive enough to manage up to 3000 gallons of water a minute – or 100,000 barrels a day for each DAF on site.”