Subpart W—Past, Present, and Future

The Mandatory Greenhouse Gas Reporting Rule (GHG Rule), 40 CFR 98 Subpart W - Petroleum and Natural Gas Systems, affects eight segments of the petroleum and natural gas industry. Starting in 2011, operators in the oil and gas production segment were required to: (1) correlate well locations with corresponding oil and gas fields for tracking and reporting purposes; (2) delineate well locations within facilities, basins, and fields; and, (3) aggregate greenhouse gas (GHG) emissions to determine applicability. Strategies had to be developed for recording data, estimating emissions, and reporting. Data was collected on production rates, equipment counts, well venting durations, gas compositions, and other parameters needed to estimate emissions. If producers could not fully comply with Subpart W requirements, the Environmental Protection Agency (EPA) allowed for use of best available monitoring methods, providing unique or unusual circumstances could be justified. Producers subject to Subpart W first had to report annual GHG emissions in September of 2012. Many shale oil and gas producers were not prepared to cope with the GHG Rule and many still may not be in full compliance. The authors discuss the requirements, challenges, and potential future implications of GHG monitoring and reporting for oil and gas producers.