Billions of dollars in federal funding secured under the 2021 Bipartisan Infrastructure Investment and Jobs Law (BIL) has started flowing into US state coffers for the plugging and remediation of orphan oil and gas wells.
Signed into law in November 2021, the BIL is a $1.2 trillion “once-in-a-generation investment” that includes $4.7 billion in funding to plug and remediate orphan wells across the nation. According to the US Department of the Interior (DOI), these legacy pollution sites are environmental hazards and jeopardize public health and safety by contaminating groundwater, emitting noxious gases and methane, littering the landscape with rusted and dangerous equipment, and harming wildlife.
The US Environmental Protection Agency (EPA) estimated in a 2020 inventory of greenhouse gas emissions that, on average, each unplugged abandoned oil and gas well emits 0.13 tons of methane per year.
When multiplied by an estimated 2.1 million unplugged, abandoned oil and gas wells, the EPA estimated methane emissions of 276,472 tons in 2019, equivalent to roughly 9.5 mtpa of carbon dioxide (CO2) assuming a 100-year global warming potential (GWP) of 34.
This is roughly 2.6% of total US energy-related methane emissions or roughly 0.2% of total US energy-related greenhouse gas emissions in 2019, assuming a 100-year GWP for methane of 34, according to a report published in Environmental Science & Technology.
The Intergovernmental Panel on Climate Change defines GWP as the cumulative radiative forcing, both direct and indirect effects, over a specified time horizon resulting from the emission of a unit mass of gas related to some reference gas.
While the EPA pegs the number of orphaned wells in the millions, there are variations in the count, depending on how each state or organization defines what is and is not an orphaned well. A survey, for example, by the Interstate Oil and Gas Compact Commission in 2018 put the range of orphaned and idle wells at around 560,000 to 1.1 million.
According to the Railroad Commission of Texas (RRC), the regulatory body that oversees Texas oil and natural gas development, an orphan well is an inactive and unplugged well that has not produced oil or natural gas for a minimum of 12 months.
But the Colorado Oil & Gas Conservation Commission defines an orphan as a well which has no owner or operator that can be found, or where the owner or operator is unwilling or unable to plug and abandon such a well. This JPTarticle described the hunt for the potentially hundreds of thousands of unknown, undocumented orphans across the country.
In October 2021, the Environmental Defense Fund (EDF) released a map showing the location of more than 81,000 documented orphan wells in 28 states that are eligible for funding under the BIL. In the spring of 2022, thanks in part to states documenting more than 40,000 additional orphan wells, EDF released an updated map showing more than 120,000 documented orphan wells in 30 states (Fig.
