Volume 8, Number 50 - March 5, 2009
brought to you online by Pinedale Online
Following the pathway of Sublette natural gas
A disconnect between consumers and producers is an unfortunate byproduct of the industrialized world.
Sometimes consumers – especially those in more urban areas – fail to see the effort, science and nuance behind the everyday conveniences they take for granted.
Ironically, the opposite is true regarding Sublette County’s natural gas production.
Instead of not knowing where natural gas comes from, we are left questioning where it goes.
And the answers might surprise you.
Somewhere in Seattle, a family’s furnace kicks on and the unseen energy source is virtually ignored.
What those family members don’t know is their house, indeed the entire neighborhood, might be heated with Sublette County gas.
But that’s not all.
Your long underwear may have come from the Upper Green River Valley.
Even the carpet under your feet may have its roots in Sublette County.
It is a long and transformative journey that begins at a Sublette County wellhead where a pressurized concoction of gases and liquids are harnesses with collection devices.
From its source, the gas is processed for transport.
Sublette County gas comes out of the ground “wet.” The raw gas is a mixture of methane (natural gas), natural gas liquids (more later), condensate (a liquid the equivalent of high-grade crude oil), and water (usually too salty to drink).
First the water and condensate is removed and stored. The water is processed and used for other drilling applications.
The condensate, valuable in its own right, is either stored on site or piped to a central facility. Randy Teeuwen of EnCana explained that his company trucks condensate to a facility in Kemmerer where it is loaded on train cars and shipped to Canada. There it is mixed with heavy oils from tar sands and shipped back to the United States for refining into diesel, gasoline, and other petroleum products.
After the gas mixture has been separated from the condensate and water, it still requires more processing. Before it can safely travel through gas pipes without freezing or causing corrosion, the gas must be dried.
The gas is run through a unit containing ethylene glycol that draws away most of the moisture. From there, it is off to a gathering facility.
On the Jonah, the gas is piped to the Jonah Gas Gathering Facility (JGGF) where a 265,000-horsepower compressor sends the gas 55 miles southwest to the Opal Hub.
The Opal Hub, located 15 miles east of Kemmerer, is the destination for nearly every cubic foot of natural gas produced in the Upper Green River Valley (UGRV).
Opal is where the gas is prepared, packaged and priced for consumption. It has a capacity of 1.45 billion cubic feet of gas per day – a billion cubic feet will heat 4 million to 5 million homes per day.
There are 37 such hubs nationwide and their purposes are multifold.
Some hubs act like market centers where gas is priced, bought, sold, delivered, held and credited. In other words gas is traded and exchanged in physical and financial markets. Those markets often have dramatically different prices as many Wyoming energy workers know too well. Because gas sources and distribution networks are not equal – some have more infrastructure and relatively low demand which drives prices down and others have less infrastructure and relatively high demand which drives prices up – the hub value of gas can be frustratingly different.
But the hub is more than a market. It is also where the gas is refined into a consumer-ready product.
Refined and ready
Even after the energy company separates and dehydrates the gas, it is not ready for consumption.
When the gas reaches Opal, it carries impurities such as carbon dioxide and hydrogen sulfide. Removing those impurities requires an amine still. Last October an amine still was transported through Pinedale. At half a million pounds, it was so big it required an extra semi to push it to its destination at a processing facility in Rio Blanco County, Colorado. According to Sara Delgado of Midstream Gathering & Processing a similar still was waiting to be installed at the facility last week.
Delgado’s company Midstream is a subsidiary of Williams, which delivers 12 percent of the nation’s natural gas through more than 15,000 miles of pipelines.
But before any pipeline company delivers gas to a consumer, natural gas liquids (NGL) – methane, propane, butane, isobutene, and pentanes – must separated from the methane. To do this, a cryogenic plant at Opal freezes the gas to minus 175 degrees Fahrenheit. Then it is run through separators that remove the NGL from the gas (methane). Typically the gas is 94-percent methane while NGL components comprise about 1 percent each. After separation, the NGL are collected for transport.
Away it goes
From Opal, the gas is sent under high pressure through two- to three-foot diameter pipelines to consumers. At that point it’s impossible to tell which gas molecules came from Sublette County and what molecules are from another source.
But if the methane is coming from Opal, there’s a good chance the UGRV can take some credit.
Gas from the Opal Hub heats homes in California, Nevada, Utah, Oregon, Washington and Idaho.
Michele Swaner of Northwest Pipeline System, another Williams Company, says 85 percent of the Northwestern states’ natural gas comes from a pipeline served by the Opal hub.
But methane isn’t the only product produced and delivered by Williams Company pipelines. NGL are transported 750 miles via the Overland Pass Pipeline to Bushton, Kan., where they are separated by a fractionator.
Natural gas customers come in all shapes and sizes. Northwest Pipeline delivers its product to utilities that serve communities, power plants that produce electricity and industrial sites that manufacture goods.
Oregon Steel uses gas from Northwest Pipeline to make armor for military vehicles and pipeline components that are used, fittingly, to build natural gas pipelines. Cardinal Glass in Hood River, Ore., uses Sublette County gas to produce fiberglass insulation and Weyerhaeuser uses the gas to mill trees into lumber.
Some of the gas is stored in huge aboveground containers while some is stored deep within the earth.
In storage facilities around the nation, vast amounts of gas are pumped into old salt mines where it is used during periods of high demand. The mines are prepared by pumping water into the caverns that dissolves the salt. That water, now brine, is pumped out of the mine and kept in holding tanks. The mine is sealed and methane is piped into the space. To retrieve the gas, the brine water is returned to the mine displacing the methane. When the high-use period is over, the brine is removed and gas is pumped in to replace the void.
NGL have a different destiny. From the fractionator, the separated compounds are trucked, railed or piped to facilities in the Gulf States where those compounds “usually garner a premium because they are so hard to get,” said Delgado.
Some of the products are used for home heating (e.g. propane) while others are used to make polystyrene foam (e.g. Pentane) or plastics (e.g. ethane). Of those plastics, some are used to weave synthetic fibers commonly found in fast-wicking long underwear.
Other compounds are made into olefins, used to make carpet.
By the time all the products are extracted the footprint of Sublette County’s gas is widely spread – and it’s getting larger.
The pipeline company Kinder Morgan is building the Rockies Express Pipeline that will increase local gas capacity connecting the Opal Hub to consumers as far east as West Virginia. Some of the 1,678-mile pipeline is already operational and the full line should be in service by November.
When completed, the pipeline will expand the reach of Sublette gas by creating infrastructure from the rocky shores of California to the hardwood hills of Appalachia and beyond.
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