As talked about in my previous article on global methane emissions, the oil and gas industry is estimated, by some, to produce around 95 million tonnes or 95 teragrams (Tg) of methane per year (compared with 215 Tg/year for agriculture). Regulations put in place by the Environmental Protection Agency (EPA) demand that this figure be reduced by 45% before the year 2025. Now, while governmental rules and regulations may change over the coming years, it would benefit us all to try and keep on track. It’s really not too difficult or expensive. The physical locations of concern include wellheads, gas gathering systems, various compressors, pumps and pneumatic controls and pipelines.
So… what are we in the oilfield doing about it?
First of all, at the basic level, there are a variety of methane sensors available on the market that can be placed in, on, and around rig-sites, pipelines and processing facilities that are prime suspects for methane leaks. Common technologies include laser diode methane detectors and infrared spectroscopy methane detectors. These may also be used as hand-held ‘sniffers’ to be waved over pipe connections or poked into enclosed spaces.
Beefing up the individual ‘fixed’ monitors, there are now companies (such as Rae Systems) that provide wireless, networked systems allowing a number of individually placed sensors to communicate with each other and with a central surveillance console up to 1000 feet (305 meters) away.
One more step upwards in fixed monitoring of methane is the so-called Open Path Gas Detector (OPGD). One manufacturer is the company Senscient . The OPGD is a methane gas laser detector that has separate transmitter and receiver assemblies certified for use in potentially explosive atmospheres and able to detect CH4 over distances of 16 to 656 feet (5 to 200 meters). A news update from Senscient names Statoil as an early user of the OPGD technology:
“Our first project for Statoil was in Canada, where Statoil is a joint-venture partner in the Terra Nova oilfield. Our success there translates well into the North Sea which has a similar environment and challenges with harsh weather.”
More recently, Statoil has been reported to have teamed up with Colorado-based startup Quanta3 LLC deploying solar and battery powered laser monitoring of methane at a facility outside of Kenedy, Texas. The system provides a 24-hour monitoring service that will alert company officials the moment a natural gas leak happens.
Happily then, it seems that there are a number of solutions to check for, and hopefully fix methane leaks at rig sites, processing plants, storage facilities and the like. But what of the network of pipelines that are used to transport hydrocarbons across the country?
As pipeline networks age, they tend to leak more which is definitely a major concern to environmentalists and communities close to the leaky pipes. It should also be a concern to the owners of the hydrocarbons that are leaking out, but often as not, operators consider that fixing methane leaks is a little on the expensive side when compared to the price of the stuff on the open market. It might be wise to remember that a “stitch in time saves nine”. A small leak can lead to a bigger leak and a bigger leak can lead to major damage, disruption, expense, and court cases.
Most pipelines are in fact equipped with sensors that measure flow rates which register a drop in the pressure when there is a leak. Unfortunately, a U.S. Department of Transportation report estimated that these sensors only find leaks in about 40% of cases. A more effective solution is to take to the air.
If we ignore an early approach to aerial leak detection which involved flying over the landscape looking for vegetation killed by escaping gas from buried pipelines, the more modern method is to use small aircraft or helicopters equipped with imaging spectrometers that image at near-infrared and at thermal wavelengths that were in part developed by NASA’s Jet Propulsion Lab and the California Institute of Technology. Using such technology, researchers from the University of Michigan were able to detect methane leaking from an underground pipeline and another 250 methane plumes from a variety of facilities in the Southwest USA.
And of course, if we are going to be airborne, what about drones? The weight of the sensor payload is somewhat of an obstacle. Drones have limited battery life, and the bigger the sensor package, the less time a drone will be able to stay in the air. However, sensors are becoming smaller and drones can and are being used to help monitor emissions over limited, yet critical sites. As sensor technology, and drone battery-life continue to improve these fun little machines will probably displace their larger and more expensive cousins – aircraft and helicopters.
It should be obvious that Big Oil has the tools and capability to clean up its act considerably with regard to methane emissions with a 2012 report suggesting that 60% of methane emissions come from leaks that are easily repaired, once detected.
But what about Big Agriculture? Agriculture, is after all, a larger polluter than the oil and gas industry (according to most sources) so what will they do to help the planet?
The biggest source of agricultural methane is rice production and a project is currently under way to introduce mitigation strategies that include a process known as alternate wetting and drying (AWD) that not only reduces methane, but also conserves water and improves fertility. By 2019, the project hopes to reduce methane emissions by 30% in its test areas that include Latin America, South and Southeast Asia.
Secondly, the bovine burping and pooting methane problem may be partially solved through genetic modification and diet. Another solution, putting a methane-catching backpack onto each cow, though amusing, hardly seems a practical solution in the grand scheme of things.
To sum up then, if the oil and gas industry can reduce up to 45% of its emissions, which is doable, and the rice ‘industry’ can reduce up to 30% of its emissions, which is proven, we are looking at a far better future for the atmosphere. Our biggest worry may eventually come from exploding herds of cows when lightning happens to strike in close proximity to them and their methane filled backpacks.
Featured image courtesy of inhabitat.com.