Development of hydrocarbon resources across the United States over the last 150+ years has resulted in over 100,000 orphaned oil and gas (O&G) wells on record and upper estimates of undocumented orphaned wells nearing a million. Leaking orphan wells introduce the risk of contaminates and greenhouse gasses— namely methane— to the soil, groundwater, and atmosphere. The U.S. Environmental Protection Agency estimated that improperly abandoned and orphaned wells contribute 3% of total methane emissions from oil and gas operations in 2021. This does not include potential contributions from undocumented wells. The nationwide effort to plug orphaned wells highlights the need for prioritization, which requires a solid understanding of well characteristics including historical drilling, geology, engineering factors, well integrity, and emission measurements.

There is no “one approach fits all” solution to the orphaned well problem. In this workshop, we will discuss a broad spectrum of topics related to the challenges of documenting and plugging orphaned O&G wells across the nation. Beginning with a history of the problem, we will showcase public databases and efforts to fill in data gaps, the variety of approaches to identifying undocumented wells, and the importance of well characterization for the purpose of plugging prioritization.