The EPA has once again overestimated the amount of pollution that comes from an oil and gas source — with potentially grave consequences for the industry. This time, the EPA has overestimated the amount of methane gas that comes from shale gas wells. A new report from the IHS Cambridge Energy Research Associates has found that the EPA’s estimates were based on too small a sample of wells, and on a method that did not conform to industry practices.
Because methane is highly flammable, those who drill new shale gas wells make every effort to minimize the emissions. This includes several methods for capturing and relieving gas, such as installing a blowout preventer at the surface.The report found that rather than base its methane emissions estimates on gas that escaped to the surface, the EPA based them on what was captured. The report noted that if methane emissions were really as high as the EPA supposed, there would be extremely hazardous conditions at the well site. It would be be “unwise” for the EPA to use its methane estimates for the basis of new policy. Furthermore, EPA proposals for more regulation of hydraulically fractured gas wells are already part of industry standards.
How did this come about? The EPA based its 2010 revised estimates on too small a sample — specifically, two workshop presentations based on just four projects in Wyoming, New Mexico, Texas, and Oklahoma. The presentations described the amounts of methane captured during “green completions” of natural gas wells. Green completions are meant to capture as much methane as possible before it reaches the surface while the well is completed. Therefore, it seems absurd to use it as a basis for estimating methane gas emissions. Yet for some reason, the EPA assumed that the wells that captured this amount methane were an exception, and that every other well must release the methane into the atmosphere because their states do not specifically regulate gas emission. In fact, IHS CERA director Surya Rajan stated that it is “common industry practice… to capture gas for sale as soon as it is technically feasible.”