Many oil companies are investigating new technologies to more cost-effectively meet the state’s new vapor pressure standard in the North Dakota cold, but one already has a cold-weather solution it is almost ready to bring to market.
Wayne King, a long-time inventor operating in the Bakken with Canadian company Tecvalco is partnering with Site Safe Solutions in the U.S. to bring an entirely different approach to the problem. King’s approach changes the way heater treaters work, which he believes can save operators 50 percent on fuel costs for conditioning crude, while at the same time improving overall safety.
The issue comes about as North Dakota set a new vapor pressure standard last year to ensure a more uniform product is being transported from the state after fiery rail car crashes forced regulators to examine the safety of Bakken crude more closely.
The new VPCR4 standard is 13.7 psi at 110 degrees and a four to one volume to liquid ratio. This is similar in concept to the more commonly cited Reid Vapor Pressure. Both of these constants can serve as an indicator of a liquid’s propensity to release volatile components, but the state has created its own VPCR4 standard.
North Dakota’s cold temperatures pose some additional challenges for meeting this new safety standard. When it is cold, a liquid holds more tightly to its volatiles, so it takes more fuel to achieve the standard.
King’s approach is quite different from the Statoil project described in our Sunday, Sept. 18 edition. His approach changes the way heater treaters work. Heater treaters have been around for five or so decades without substantial change, but with the new requirements some operators have reported their heating tubes are wearing out more quickly during winter as they are turned up to accomplish a task they weren’t specifically designed to do.
“Because they are having to run the fire tubes much harder than in the past, the life expectancy has dropped from 2 to 5 years to just a few months, and some companies are telling me their fire tubes are lasting 30 to 60 days even,” King said.
His new heating system uses a passive flame bed rather than a fire tube with about 2 ounces of fuel pressure — just like a home barbecue system — and also includes a flame arrestor, a common safety device used to prevent explosions.
The external heat is applied to a mixture of water and glycol contained in a closed-loop system under vacuum. The mixture thus boils at a much lower temperature, and the rapidly expanding steam helps accelerate full energy transfer to the crude oil. As the steam loses energy and cools, it condenses back down to the heater for yet another cycle.
“The beauty of the unit is that in the tests we have done, we find that we consume 50 percent less fuel,” King said. “We are running at 70 to 80 percent thermal efficiency, versus a fire tube that runs at 30 to 45 percent. We are adding heat to the tank to get pipeline spec crude oil out of the tank, unlike what we could previously do with a fire tube.”
The North Dakota Industrial Commission is allowing this new type of unit to be 21 feet from the tanks instead of 125, King added, further lowering costs by reducing the overall size a lease needs to be.
King’s new technology is being tested in North Dakota with several operators, including QEP Energy, which installed the first testing unit about a year ago. They have also engaged the Saskatchewan Research Council to perform independent third-party tests to verify the reduced fuel consumption and longevity claims being made.
“We face many challenges in the industry,” he said. “We face challenges to be more efficient. We face challenges with low oil prices. Our industry is forever moving forward. Efficiencies and economics are very important to us, as well as safety and the environment.”