How and Why do Orphaned Oil and Gas Wells Need to be Plugged  

Orphaned wells are oil or gas wells that are no longer in operation, but they were not properly dismantled and plugged. Leaving them opened in this state allows greenhouse gas emissions to escape the well and for it to potentially leach chemicals into the ground.  

Plugging orphaned wells is a meticulous process that must be followed correctly to maximize safety and prevent the leakage of chemicals into the surrounding groundwater or into the atmosphere. Here are the steps to plugging, improving, and monitoring an orphaned well: 

Assessment and Preparation 

Various technologies and techniques are used to measure the well’s current condition and the surrounding area. This might include reviewing the surface conditions to ensure they’re suitable for heavy machinery and have the right accessibility. Some orphaned wells are found in backyards, near schools, farms or even under sidewalks, so a ground assessment is essential so the remediation team can make the right plan. They will remove any residual oil, water, or gas from the well and use equipment to clean out the wellbore (which is the actual hole dug for the well.) 

Organizations such as the Well Done Foundation, a nonprofit organization committed to spotting and plugging orphaned wells, will perform testing to assess the well’s negative impacts. This would include greenhouse gas emissions testing to gauge how methane and other gases are escaping from the well. This information can help companies submit the most labor and equipment resources to the most polluting orphaned wells, to maximize the plugging effort’s impacts.  

Plugging the Wellbore 

After the team assesses the well and cleans out the wellbore, they then need to determine the best way to plug the well. They will often use cement as a primary material, as it is durable and provides a tight seal. They will pump the cement into the wellbore to create a full seal that seeps into various cracks to prevent fluid from migrating into groundwater. Organizations might also utilize a compound called bentonite, which is a clay that swells making it ideal for sealing gaps.  

Mechanical plugs or what are known as “bridge plugs” are often used to permanently seal the wellbore. These plugs can help keep cement and well chemicals away from groundwater and other underground layers by isolating the cement into different sections that are each tested to confirm a contained seal.  

Restoring the Area 

After plugging is completed, the organization responsible for the project will also typically improve the surrounding area. This will include removing all equipment and debris from the site, including any structures associated with the well. They might also remediate any contaminated soil by excavating the affected area and using bio-remediation techniques to handle pollutants. The team might also regrade the surface around the well to improve drainage and prep it for vegetation replanting with native plants that will help the area blend into the area and support native animals. After this restoration, the organization will conduct ongoing monitoring to ensure vegetation growth continues, there’s no erosion, and the well was plugged successfully and there are no emissions.