Natural gas flaring - it's an issue North Dakota has dealt with since Black Gold was first coaxed from beneath its prairie earth. For years, it was just one of those things associated with a new well. But when advancing technology began unleashing the Bakken's oil potential, flaring, too, was unleashed.
It's been a hotbed topic ever since, so much so that the State of North Dakota initiated target dates requiring producers to capture 76 percent of the natural gas produced at a well site by Oct. 1, 2014; 77 percent by Jan. 1, 2015; and 85 percent by Jan. 1, 2016.
Those requirements are proving to be fertile grounds for innovation and advancing technology in dealing with natural gas when infrastructure can't keep up with production. Just consider what happens when you combine the talents of a mechanical engineer from Stanford University, a chemical engineer from the University of New Hampshire, and another mechanical engineer from Colorado State University and they decide to help solve a problem in the North Dakota Bakken.
The result becomes innovation through companies such as GTUIT (pronounced Gee-to-it), a Billings, Mont., company focusing on reducing natural gas flaring in North Dakota by separating out heavier hydrocarbons at the well site with a technique that's as mobile as a cat in the night and as flexible as a gymnast.
Brian Cebull, Mark Peterson, and Jim Haider founded GTUIT in 2011 after recognizing the need to reduce natural gas flaring, the importance of the ability to be able to deal with varying, continuously fluctuating flows within a well, and the need to be able to stay for as long - or as little - as possible until the natural gas can be transported to a gathering facility via pipeline.
Cebull, GTUIT president and CEO, is from Montana and the three men worked in the Bakken. "We saw the problem in our own backyard," he said. His expertise centered on operations on the upstream side of production.
Bakken crude is sweet, light crude comparable in quality to the United States standard of West Texas Intermediate crude. The natural gas associated with a Bakken well is typically high quality, as well. "This is amazingly rich gas," Cebull said. Essentially, what a GTUIT system does is target separation of heavy hydrocarbon gases such as propane, pentane and butane. Those gases have the highest BTU (British thermal unit), can be readily transported, and easily liquefied because they don't require the intense cryogenic refrigeration down to temperatures necessary to liquefy gases such as methane.
Typically, natural gas, oil and produced water are separated at a well site, but the natural gas is usually shipped out for further processing. However, Cebull said, a well has a variety of moving dynamics and flows are not constant. Instead, they continually fluctuate.
In addition, not all well sites have pipelines readily available to move the natural gas to a gathering or processing facility, which is why flaring is so prevalent.
Typical natural gas processing equipment doesn't handle declining flow rates well and high initial declines are prevalent in Bakken wells. For example, a typical Bakken well's productivity declines 50 to 60 percent within its first six months of productivity, 70 to 75 percent within its first year.
The GTUIT system is mobile, Cebull said. Their technology takes a separation system and puts it on a semi tractor-trailer. It can be completely taken down and set up on a new well site within 24 hours. Its innovative technology and service captures NGLs - natural gas liquids - at the well site and its patent-pending flow control system is designed to deal with fluctuating flows within a well.
The equipment is computer controlled, although monitored by a person daily to help ensure safety, and can stay at a well site anywhere from a few weeks to several months, Cebull said. "However long it's necessary," he added. How long it remains in place depends on pipeline availability - it may have to stay until a pipeline can be constructed to the well site, for example. Sometimes existing pipelines might not have enough capacity and the GTUIT system stays on site until more pipeline capacity becomes available.
The system compresses the natural gas, refrigerating it down to temperatures of minus 20 to minus 40 degrees Fahrenheit, which are necessary to separate out the heavier components. Leftover gases, such as methane and ethane, are released in flares maintained by the well operator or converted to compressed natural gas (CNG), liquefied natural gas (LNG), or to electricity for use at the well site.
The gases separated by the GTUIT system, which are within the oil itself, aren't flared and instead available for commercial use.
Basically, the GTUIT on-site technology reduces the amount of natural gas flared as well as the amount of volatile organic compounds emitted from a flare stack.
The system design, refrigeration equipment, and combination of processing and safety equipment prompted GTUIT to become ISO 9001compliant. The company expects to receive ISO certification in February 2015. ISO, International Organization for Standardization, develops international standards to ensure quality, safety, and efficiency for products, services, and systems.
The system can be used at pad sites with multiple wells, Cebull said, and in situations where there is a variety of gas composition among the wells in addition to varying flow rates.
GTUIT launched its prototype, first generation mobile equipment in 2012 at a well site, "which hadn't been done before in the Williston Basin," Cebull said.
It was a well site demonstration that caught the attention of Hess Corporation, one of the Bakken's largest oil producers. Hess accounts for about 10 percent of North Dakota's oil and gas production, said its onshore communications senior manager John Roper. He anticipates the company's natural gas flaring could drop to 10 percent of its gas production by 2017 or sooner.
Technology such as what GTUIT developed is one "tool" that can help reduce flaring, Cebull added. While GTUIT works with other companies in the Bakken, the bulk of their current operations are in conjunction with Hess. Every new step or system deployed in the effort to reduce flaring is a step in the right direction, he said. In combination with a GTUIT system, others can come in and work with the CNG or LNG - or even making it easier to produce electricity at a well site from the natural gas that otherwise would have been flared.
While North Dakota's Bakken is the focus of GTUIT's efforts, Cebull said "we're going to grow in an organized manner," to determine where else the mobile units could be used in other shale oil plays in the United States. North Dakota's unique environment - its bitterly cold and windy winters and blistering summer days - provide opportunities to put the equipment through the rigors of testing. "I think North Dakota is a great proving ground," he said.