CCUS 2022

Summary

Claire Grove, Matthew Merrill, Geological Survey

The U.S. Geological Survey has assembled a dataset of approximately 80,000 unplugged orphaned oil and gas wells in 23 states. The definition of an orphaned oil or gas well varies across data sources; our dataset includes oil or gas wells for which the following criteria are met: 1) no production for an average of 12 months (6 to 24 months depending on the state), 2) the well is unplugged, and 3) there is no responsible party to manage the well for future re-use or for plugging and abandonment. The dataset includes location coordinates, location precision, and additional information such as API number for each unplugged orphaned well. Oil and gas wells, especially unmanaged, unplugged ones like those in the orphaned well dataset, are known sources of methane, a greenhouse gas. In addition, these wells can potentially provide leakage pathways for sequestered carbon dioxide (CO₂) out of a storage reservoir. If CO₂ or brine leak out of a storage reservoir, they could contaminate underground sources of drinking water (USDW) or the CO₂ could be emitted to the atmosphere. Therefore, the locations of unplugged orphaned wells are important for assessing risk in prospective subsurface CO₂ sequestration projects. The information gathered in this dataset was obtained through direct requests to the respective state agency overseeing oil and gas wells or downloads from their online databases. Many state agency datasets include location information in only the Public Land Survey System (PLSS) format, which is commonly known as Township and Range. To determine the latitude and longitude of the wells, a tiered conversion system was employed using an automated Bureau of Land Management (BLM) tool, followed by purpose-built geographical information system (GIS) processes, and finally, manual editing. Each well is provided with a location precision estimate based on the level of detail in the original data. The goal of our work is to make the orphaned well dataset available online for decisionmakers, as well as researchers and the public. Future activities for this project include the planned release of an online map to facilitate access and visualization of the data.