Orphan wells

Orphan, orphaned, or abandoned wells are oil or gas wells that have been abandoned by fossil fuel extraction industries. These wells may have been deactivated because had become uneconomic, failure to transfer ownerships (especially at bankruptcy of companies), or neglect and thus no longer have legal owners responsible for their care. Decommissioning wells effectively can be expensive, costing several thousands of dollars for a shallow land well to millions of dollars for an offshore one.^[1] Thus the burden may fall on government agencies or surface landowners when a business entity can no longer be held responsible.^[2]

Orphan wells are a potent contributor of greenhouse gas emissions, such as methane emissions, contributing to climate change. Much of this leakage can be attributed to failure to have plugged properly or leaking plugs. A 2020 estimate of abandoned wells in the United States was that methane emissions released from abandoned wells produced greenhouse gas impacts equivalent to three weeks of US oil consumption each year.^[2] The scale of leaking abandoned wells is well understood in the US and Canada because of public data and regulation; however, a Reuters investigation in 2020 could not find good estimates for Russia, Saudi Arabia and China—the next biggest oil and gas producers.^[2] However, they estimate there are 29 million abandoned wells internationally.^[2][3]

Abandoned wells have the potential to contaminate land, air and water, potentially harming ecosystems, wildlife, livestock, and humans.^[2][4] For example, many wells in the United States are situated on farmland, and if not maintained could contaminate soil and groundwater with toxic contaminants.^[2]