Methane emissions have a significant impact on climate change, perhaps a greater impact than even carbon dioxide emissions. Methane is released into the atmosphere from a variety of sources and in a number of ways.
Fortunately, advances in technology provide effective methods to greatly reduce the amount of methane that is released.
Methane is released primarily by landfills, cattle, and leaks from oil and natural gas production.
Oil and natural gas activities represented 28 percent of the total 2012 domestic methane emissions. The equivalent of 127 million tons of carbon dioxide was emitted as methane from production, processing, transmission, storage and distribution gas. Methane emissions from crude oil production and refining were the equivalent of 32 million tons of carbon dioxide. Nine percent of the nation’s greenhouse gas pollution is attributed to methane.
The U.S. Environmental Protection Agency (EPA), however, cites various available technologies as key to helping the oil and natural gas industries meet a new policy statement from the Obama administration regarding methane emissions.
The Strategy to Reduce Methane Emissions is a key component to the Climate Action Plan, the plan President Obama announced in June 2013. The administration says the strategy builds upon the earlier successes achieved through voluntary efforts and targeted regulations.
The plan calls for a reduction of carbon emissions by 17 percent below 2005 levels by 2020. Carbon dioxide is a far more abundant greenhouse gas than methane, but methane has a far greater impact. Methane, the second most prevalent greenhouse gas emitted from human activities, has a shorter lifetime in the atmosphere, but is more efficient at trapping radiation. As a result, according to EPA, methane’s impact on climate change is 20 times greater than carbon dioxide over a 100-year period.
Emissions control technologies targeting volatile organic compounds and methane, with particular focus on oil and coproducing wells, liquids unloading, leaks, pneumatic devices and compressors offer cost-effective ways to substantially reduce methane waste and emissions.
The collected data shows a substantial amount of methane emissions originating from leaks from gas production, gas processing and transmission. Studies show most methane and volatile organic chemical leaks happen from only a few components at a limited number of sites.
Regularly scheduled inspections of project infrastructure help companies know the points wwhere methane is being released. Advances in computer software help companies organize the necessary level of inspections so that repairs or replacement of equipment can be accomplished to deal with any leaks within a oil or natural gas drilling, pipeline and processing project.
In the past, companies had to rely upon paper records and spreadsheets to manage inspection and workflow schedules. That’s an inefficient process that not only is a waste of the company’s resources, but likely failed to address the amount of methane leaks within a large infrastructure.
Today’s software helps companies establish inspection and workflow schedules. The schedule can be as broad as inspection of one or more compressors or as detailed as inspection of individual seals. Through a centralized web database, the administrator can assign an inspection and the work crew can communicate the results and any repair work required.
By utilizing mobile devises, the inspection can be assigned and the results reported quickly and without the need for paper records. The chance of duplicating inspections of specific sections of infrastructure is greatly reduced if not eliminated.
The software generates inspection reports automatically according to the desired schedule. These reports can help the company meet any documentation requests from EPA or elsewhere.
Several other technologies are available to help oil and natural gas companies reduce methane emissions.
New technologies in the use of compressors can capture emissions and route them back to the process. Dry-seal designs can control emissions in centrifugal compressors. These compressors have lower emissions, require less maintenance and are more energy-efficient than wet-seal compressors. Even with wet-seal systems, it is possible to capture emissions from seal oil and route the recovered gas back to the compressor or another process, or burn the gas.
Data on methane emissions from hydraulically fractured wells is limited, but EPA estimates emissions range from 44,306 to 247,000 tons per year. Reduced-emission completions may be effective in some producing wells.
Other technologies for controlling emissions are being studied. These include gas injection, natural gas liquid recovery, and the use of gas for power generation for local use.
EPA’s Natural Gas STAR Program is a voluntary partnership that encourages oil and gas companies to adopt cost-effective technologies and practices that improve efficiency and reduce methane emissions.
Photo Credit: Methane Emissions and Tech/shutterstock