A well can be hydraulically fractured multiple times to re-stimulate the flow of oil or gas. Once the operator determines the well to be past production or unsuccessful, it is shut down. The state regulates the well abandonment process, often mandating the materials used to plug the well and their placement. Depending on the state, the regulatory agency might also send staff to witness the plugging of the well. In addition to proper well abandonment at the end of the production phase, ongoing inspection and maintenance is required.
Plugging the well involves permanently sealing it with cement and other materials to prevent fluid migration to aquifers, surface water, and surface soils. To maintain integrity, multiple plugs are placed in the wellbore, along with fluids at specific pressures in certain well depths. The operator conducts tests to ensure stability. The steel casing of the wellbore is cut off below the surface and capped with a steel plate. The company removes any remaining equipment from the site, reducing the footprint down to the wellhead. The company then usually works with the surface owner – and is often required to by state law – to restore the land, soil, and vegetation as specified in the surface use agreement (or according to regulatory requirements on state and federal lands). According to the API community engagement guidelines, “Communities can expect the land to be reclaimed or restored as close as possible to its original or current surrounding state.” The operator may also install a marker on the site that indicates the well location, well number, and operator to facilitate site identification in the future.
In some cases, if the company has other nearby wells still in production, the well might be converted to an injection well that can accept produced water from other sites. These wells are reclassified as Underground Injection Control (UIC) Class II injection wells. Established by the Safe Drinking Water Act (SDWA) in 1974 and regulated by the U.S. Environmental Protection Agency, the UIC program sets forth requirements for different types of injection wells in order to ensure the protection of underground sources of drinking water (USDWs). Class II wells accept liquid wastes from the oil and gas industry (for more information on the UIC program, see Appendix C).
Restored site. Photo from Bureau of Land Management, “Visual Resource Management: Final Reclamation, Part 5” (May 2006).
With the closure of the project site and departure of the temporary workforce, the community might undergo an economic bust as described in Stage 3. For this reason, it is important to plan for project closure from the outset and to use revenues from the project to strengthen local infrastructure, build community services, and diversify the local economy. Community representatives should also bear in mind the potential long-term impacts of activities associated with the project (for an example, see Box 16: A Case Study: Employee Housing).
Air & Water Quality and Safety
If wells are not properly sealed when they are abandoned, they can pose a safety risk to residents and livestock, as well as air and water quality risks, given that contaminants could be released into the air or migrate to ground and surface waters. When this has been suspected of occurring, it has been linked to old, historically abandoned sites (orphaned wells). A 2013 study conducted in New York found that three-fourths of the abandoned oil and gas wells had never been plugged. The National Petroleum Council also acknowledged the problem nationwide in a 2011 working paper. Furthermore, a 2014 study of 19 abandoned wells in Pennsylvania – some dating back to the 19th century – found that not only were most of them unplugged, but both plugged and unplugged wells were also leaking methane. Extrapolating the amount released from the wells under study, the researchers estimated that such abandoned wells could be responsible for 4%-7% of the state’s methane emissions in 2010.
The Interstate Oil and Gas Compact Commission (IOGCC), in collaboration with the U.S. Department of Energy, has been studying the problem of orphaned wells and making recommendations to the states, which are ultimately responsible for locating and plugging the wells. As of 2007, the states had identified about 60,000 such wells, with potentially 90,000 more yet to be located. The IOGCC concluded that while the states have improved their response to the problem, funding remains an issue. The IOGCC therefore recommended that wells presenting the greatest safety risks be prioritized and urged states and industry to collaborate in finding creative solutions.
Quality of Life—Economic Impacts
As mentioned above, the local economy can undergo a contraction after the project closes; economic opportunities accompanying the project dwindle, and project workers and employees in associated industries leave the area. The community can suffer a corresponding loss of revenue for infrastructure and critical services, such as public health departments and policing.
Quality of Life – Noise Impacts
In the decommissioning phase, there can be temporary noise impacts from construction and earth-moving equipment and some truck traffic as the operator removes all equipment, grades the site, spreads topsoil, and restores vegetation in the area.
Quality of Life – Visual Impacts
As described above, in many cases the land can be restored to the condition specified in surface use agreements or in accordance with state and/or regulatory requirements. In some areas of the country, however, significant deforestation can persist for many years after decommissioning. For example, in Pennsylvania, 64% of projected well locations are on forested lands; as a result, 34,000 to 82,000 acres of forest may be cleared by 2030.
From the beginning of the development process, it is important that local officials, company representatives, and other local stakeholders plan for project closure in order to minimize the impacts of the company’s withdrawal and counteract a potential bust. Such planning could focus on building long-term community assets, establishing “rainy day” funds, diversifying the local economy, and avoiding unsustainable investments in infrastructure that would require ongoing revenue to maintain. Finally, holding community meetings focused on the decommissioning phase can help to clarify the company’s activities and timeline and identify any issues or concerns.
In addition to making an effort to restore the land as close as possible to its original state per the API guidelines, the company can maintain a dialogue with local officials and community members to get their input during the decommissioning process. It can anticipate safety and environmental risks that could arise from the site and strive to reduce or eliminate those risks. The API guidelines recommend adopting a “consistent and forward-looking focus on safety and the environment.”
State officials have a role in ensuring that wells are properly plugged and abandoned. At this stage, any surface use agreements that were signed prior to site development can help to guide the site restoration.
Property owners can work with the operator to make sure that the site is properly restored to the specifications in the surface use agreement.