How Should We Manage Methane Emissions From Shale Gas?
Proponents of shale gas have proclaimed that it is a climate solution – our bridge to the energy future – but methane emissions from shale gas development could make it a bridge to nowhere. Until recently, scientific research has significantly underestimated methane emissions from shale gas. As a result, there is growing concern that shale gas is not a climate-friendly alternative to other fossil fuels. To mitigate climate change, both states and the federal government need to require methane emissions reductions from shale gas operations. As current federal efforts will not achieve the necessary emissions reductions, states have the opportunity to play a pivotal role in shaping shale gas development.
Methane emissions, like other greenhouse gases, are experiencing a worrisome upwards trend.
Methane constitutes eighty to ninety-eight percent of natural gas and is an important greenhouse gas. The majority of methane emissions from natural gas facilities come from gas compressors, pneumatic controls, and fugitive emissions or leakage. In 2009, natural gas systems emitted 715 billion cubic feet of methane. According to the Intergovernmental Panel on Climate Change, methane has a 25 times greater global warming potential than carbon dioxide over 100-year timeframe. The shale gas boom could contribute significantly to climate change if the federal and state governments continue to permit unchecked methane emissions.
Moreover, the EPA’s 2011 Greenhouse Gas Inventory found that many sources of methane emissions in shale gas development have been significantly underestimated, particularly methane releases from the wellhead and processing facilities at the well pad. While opinions still differ on both research methodology and total methane emissions, there is growing agreement that estimates of methane emissions from shale gas are too low and that methane emissions reductions are necessary to mitigate climate change.
Despite growing concern over the climate change impacts of shale gas, neither the federal government nor most state governments have tackled the methane problem head-on. Only a handful of operators have incorporated methane-reducing technologies into practice through the EPA’s voluntary Natural Gas STAR program. States therefore have an opportunity to take the lead in reducing methane emissions.
In April 2012, the EPA promulgated the first federal regulations on air pollution from oil and gas hydraulic fracturing. The EPA delayed implementation until 2015 in response to industry comments questioning the timeframe feasibility. The final regulations address volatile organic compounds (VOCs) directly, and the EPA expects the regulations to yield the additional indirect benefit of reducing methane emissions. These regulations require reduced emissions completions (“green completions”) for all new wells. Operators clean out the wellbore after drilling or repair, and normally the gas is flared or vented. Instead of releasing the gas, a green completion separates methane gas from condensate for future use. Green completions on new wells reduce VOCs from the new 11,000 hydraulically fractured wells yearly by ninety-five percent.
The EPA air pollution regulations are aimed at reducing air pollution from VOCs. Nevertheless, the EPA’s approach has several flaws: (1) the regulations do not address methane directly, (2) the implementation of the regulations is delayed until 2015, (3) the regulations only affect new sources, and (4) most importantly, the regulations would only reduce methane emissions by around ten to fifteen percent.
Similarly, the Department of Energy (DOE) has not yet taken direct action on methane emissions from shale gas. The Secretary of Energy Advisory Board’s Shale Gas Production Subcommittee developed a report with twenty policy recommendations including greater transparency, water quality monitoring, and air quality improvements. Three of the recommendations relate to methane. The Subcommittee further recommended research on underground methane migration and “launching a federal interagency planning effort to acquire data and analyze the overall greenhouse gas footprint of natural gas use.” So far, the DOE has not taken action on these recommendations since funding is still needed.
Two states, Pennsylvania and New York, are actively addressing shale gas development in the Marcellus Shale Play. The Pennsylvania legislature passed Act 13 to amend its Oil and Gas Act. Act 13 covers three general areas: impact fees for shale gas wells, amendments regarding surface and subsurface operations, and limitations on local government’s power to place any additional restrictions on oil and gas operations beyond the state law. Since Act 13 fails to address methane emissions from gas operations, advocates should promote emissions control technologies in Pennsylvania.
New York has taken a more precautionary approach to shale gas development than Pennsylvania. New York’s approach includes a temporary moratorium on gas drilling permits, an assessment of shale gas impacts, and proposed regulations. New York’s proposed regulations are stronger than Act 13 because the proposed regulations would require greenhouse gas planning, leakage management, and flaring instead of venting. Flaring will reduce emissions because venting releases large amounts of methane and VOCs. Even so, New York should finalize its proposed regulations and take additional steps to reduce methane emissions.
Methane (CH4), composed of one carbon holding onto 4 hydrogens, is a more potent greenhouse gas than CO2
The methane problem is surmountable. Methane emissions and leakage have been a challenge because they occur at various locations during gas extraction and processing. Nevertheless, some companies are already beginning to reduce methane emissions through the EPA’s Natural Gas Star program. By using a combination of specific cost-effective technologies it has been shown that gas operators can reduce methane emissions by as much as eighty-five percent. These emission reduction technologies, such as low-bleed pneumatic controllers, desiccant dehydrators, vapor recovery units, and better pipeline maintenance, can be win-win improvements. Companies that capture methane will reduce emissions and can sell that methane at a profit.
In the face of insufficient federal action, states should address methane directly and establish a phased-in approach to the regulation of existing sources. For existing facilities, states should establish performance standards for each source of emissions. Decision-makers would do well to proceed with caution and require methane mitigation in shale gas operations. Like most resource booms of the past, shale gas development holds both promise and surmountable risk to our climate stability.