North Dakota’s new vapor pressure standards were designed to increase the safety of the Bakken’s sweet crude, but the new standards present some challenges for even the safest method of transportation — pipelines.
While the state’s new vapor pressure standard is achievable at the wellhead with existing technology, it presents special challenges in the winter. Technology exists to address these issues, but keeping them economical is key, particularly in a low-price environment.
Energy companies have taken on the issue in a variety of ways. Some have grouped more wells together, to make investments in conditioning facilities more cost-effective. Others, however, may take the opposite extreme, pulling back from pipelines to continue trucking their crude instead.
Statoil, meanwhile, is going after the issues in a high-tech way, one that could innovate the entire process and, down the line, make the Bakken a more competitive play.
Darren Schmidt, a petroleum engineer for Statoil, and a member of the Williston chapter of the American Petroleum Institute, was on hand at the group’s most recent meeting to discuss his company’s approach to the challenges the state’s new vapor pressure standard can present, particularly during winter.
“Weather plays a role, and science plays a role in what you can realistically achieve with vapor pressure,” Schmidt said. “We are heading into our second winter under the new order. A lot of us are a little better prepared, but we still have room for new technology.”
A bad rap
Bakken is light sweet crude and, as light sweet crudes go, it falls in the mid-range of volatility. It has nonetheless gained a bad reputation, thanks to several fiery derailments. The first leveled the downtown of Lac-Mégantic, killing 49 people. Subsequent explosions in Casselton and Alabama kept the issue at the forefront of regulatory attention, prompting a new standard for vapor pressure.
North Dakota regulators now require Bakken crude to meet a new vapor pressure standard to ensure a more uniform product is being transported from the state. That new VPCR4 standard is 13.7 psi at 110 degrees at a four to one volume to liquid ratio, settled on as a means to ensure flammable components that were blamed for fiery rail car crashes are driven off prior to transport.
The new standard is similar in concept to the more commonly cited Reid Vapor Pressure — terminology that is still in widespread use across the oil patch. While both can serve as an indicator of a liquid’s propensity to release volatile components, VPCR4 is the state’s own standard, selected because it allows more accuracy than the old, 1930s standby.
Achieving the state’s new standard is relatively easy to achieve at well heads during the summer. Heater treaters, around for 50 years now without major changes to technology, can heat crude to the state’s prescribed temperature, forcing out many of the components that were blamed for causing Bakken crude’s issues.
But it costs a lot more when it is cold, and there can be issues in storage systems if liquids are moving in and out, leaving behind vapors that can seep back into solution later. That forces additional control measures and bumps up costs to achieve shipping standards.
Those additional costs are making Bakken crude less competitive as compared to other light sweet crudes, which don’t face any particular vapor pressure standard.
Changing the game
To improve its conditioning technology, Statoil started with some computer modeling to get a better handle on all the issues crude oil can face as it goes down the line, from wellhead to tank storage to final destination by pipeline.
After that, they designed potential improvements, ranging from mechanical to chemical. Sonication, chemical additives, gels and more were all considered. Testing for selected options were then subcontracted to the Energy and Environmental Research Center and SGS North America Inc.
This type of subcontracting is something the EERC specializes in, and is available to any Bakken company, Beth Kurz, who is heading up the Statoil research project for EERC, said.
“We have a whole gamut of services that companies may have interest in,” she said, “including analytical labs and computer modeling.”
EERC also works with the Department of Mineral Resources and industry partners on widespread Bakken issues, such as flaring, fugitive emissions and water management, to find solutions that can help position the Bakken as a premier tight oil play.
“We make sure the research we are doing addresses industry concerns,” Kurz said. “We don’t just do research for the sake of doing research. We want to address a problem and find solutions to the challenges they face in the Bakken.”
Schmidt sees the research Statoil is working on with its partners as having great potential to make the Bakken more competitive down the line, and is proud of his company’s proactive approach.
“This would enable us to have a technology where we can really increase reliability,” he said. “So we are pretty excited about the flexibility of this technology, and what we might be able to do with it.”