In June 2012 Bakken oil production reached 660 Mb/d with 0.7 Bcf/d of associated natural gas. A third of that associated gas (32 percent or 0.22 Bcf/d) was flared at the wellhead. There are sound environmental and economic reasons why flaring occurs. In other States like Texas the percentage of flaring is tiny (0.5 percent). The answer to flaring is better infrastructure but huge investments in North Dakota could still not be enough to eliminate flaring. Today we shed new light on the issue.
What is flaring? Flaring occurs when the natural gas produced from an oil and/or gas well is captured and burned (we will get to why its burned next). There are a couple of broad categories of flaring. The first category is a limited activity carried out by producers during well completion. In this case, the producer captures gas that bubbles up the well casing that would otherwise escape into the atmosphere and then flares that gas separately. The second, more significant category consists of a continuous flaring process to burn the associated gas that comes to the surface with the oil once a well is producing. We are going to concentrate on the second category.
Why does flaring occur? There are two reasons that flaring occurs. The first is environmental. In any situation where gas would otherwise escape into the atmosphere (known as venting) it is better for the environment to flare that gas. Flaring is safer than venting because natural gas (methane) is 20 times more environmentally damaging (e.g. to ozone) if vented into the atmosphere than if it is flared first. The byproduct of flaring is CO2 – not tremendously good for the environment but a heck of a lot better than methane. So if you are going to get rid of methane, flaring is better than venting.
The second reason for flaring is economic. If you drill a well for oil and start production, you can capture the oil in tanks and transport it to market in trucks long before pipeline infrastructure is available. Oil is much easier to store and transport than gas. Any associated gas produced from the well is not feasible to capture and transport to market until a gathering pipeline infrastructure is in place. The companies that invest in gas gathering pipelines and the gas processing infrastructure necessary to treat the natural gas before transporting it to market will only make such an investment once they know how much associated gas is being produced. The answer to that question is not easy to predict until oil production gets underway. So if you ban flaring (assuming that venting is verboten) then you would be banning oil production and you would never know if the associated gas could be recovered because you would not be drilling the well in the first place.