We’ve all seen pictures like this before on the TV or maybe you’ve driven past an oil rig and wondered “what is that?” You are not alone. I have driven past countless thousands of oil well sites and have always ask myself, “Why are they burning? and What is it that is burning?”
I have, in the past, ask many friends that I know who have worked in or around the oil fields this very question. As I continue to drive past more of them, I always wondered “Isn’t there something they can do with the gas that is burning?”
The answer as it turns out is more complex than I imagined, and yet, still leaves one to wonder why it’s happening in the first place. The answer as it turns out is more complex than I imagined, and yet, still leaves one to wonder why it’s happening in the first place.
Associated Petroleum Gas (APG), or associated gas, is a form of natural gas which is found with deposits of petroleum, either dissolved in the oil or as a free gas cap above the oil in the reservoir.
Historically, APG was, and still is in many ways, a waste product from under ground petroleum extraction. It may be a stranded gas reserve due to the remote location of the oil field, either at sea or on land. The gas is then simply vented or, preferably, burnt off in gas flares. When this occurs it is referred to as flare gas.
APG flaring is controversial since it is a pollutant, a source of global warming and a waste of a valuable fuel source. APG is flared in many countries where there are significant power shortages. In the United Kingdom, gas may not be flared without written consent from the UK government to prevent unnecessary waste and protect the environment. Russia is the world leader and contributed 30 percent of total global APG flared in 2009.
The World Bank estimates that over 150 billion cubic meters of natural gas are flared or vented annually. Flared natural gas is worth approximately 30.6 billion dollars and equivalent to 25 percent of the United States’ yearly gas consumption or 30 percent of the European Union’s annual gas consumption.
Growing up, I, like many that I know, were always told that the oil in the ground was from dinosaurs from the days of ol when dinosaurs roamed the earth having dinosaur parties of epic proportion. We would often take tips to the La Brea Tar Pits in Los Angeles, California to see the vast pits of tar that was left over from dinosaur extinction, sadly, that was a myth.
The notion that petroleum or crude oil comes from dinosaurs is fiction. Oil formed from the remains of marine plants and animals that lived millions of years ago, even before the dinosaurs. The tiny organisms fell to the bottom of the sea. Bacterial decomposition of the plants and animals removed most of the oxygen, nitrogen, phosphorus and sulfur from the matter, leaving behind a sludge made up mainly of carbon and hydrogen. As the oxygen was removed from the detritus, decomposition slowed. Over time the remains became covered by layers upon layers of sand and silt. As the depth of the sediment reached or exceeded 10,000 feet, pressure and heat changed the remaining compounds into the hydrocarbons and other organic compounds that form crude oil and natural gas.
The type of petroleum formed by the plankton layer depended largely on how much pressure and heat were applied. Low temperatures, caused by lower pressure, resulted in a thick material, such as asphalt. Higher temperatures produced a lighter petroleum. Ongoing heat could produce gas, though if the temperature exceeded 500°F, the organic matter was destroyed and neither oil nor gas was produced.
But the question still remains, why is this gas burned-off? One of the things that I always noticed was the oil wells are located in the middle of nowhere. The nearest town most often is 50 to 100 miles away from these small created cities where oil is extracted from the ground. Because of this, it is not cost effective to process this left over by-product, much less try to store it.
But that still didn’t answer my question. Why was it being burned and not used for something else? I would think to myself “if you can build a small city out in the middle of nowhere, you can certainly build something that the gas being burned could use. Maybe to power generators, process plastic waste into more fuel to be refined later at a refinery.
As it turns out, much to my pleasure, the oil fields of the Bakken, North Dakota have started doing just that. Because the oil fields are so remote, the crude oil is shipped by train to the refineries to be processed. Trains are powered by giant electric motors that are powered by giant diesel engines. The BNSF railway has started using this left over by-product to power the locomotives that carry the crude oil.
In the end, the refineries process the crude that is dug out of the ground and turn it into many different types of fuel.