Typically, plug and abandonment of wells occur on deteriorated or abandoned water wells that can include windmill wells, groundwater monitoring/remediation wells, irrigation wells, rig supply wells, and domestic wells. Over time, construction of these wells has deteriorated. Whether the well is no longer used or needed, preparations must be made for the plug and abandonment process. This is where wireline services will be needed. Leaving the well open or covered can lead to contamination and the risk of personal safety to both humans and animals.
Importance of Plug and Abandon of Wells
Groundwater is a valuable natural resource. Abandoned wells are direct conduits to the subsurface aquifers below. Even a single abandoned well can already contaminate groundwater for miles. To maintain the aquifers’ water quality and protect people or animals from falling in the well, it is essential to establish abandon procedures which differ depending on a lot of variables.
Usually, contaminants that offer cause for concern include pesticides, fertilizers, and other harsh chemicals. When a well is open or abandoned, it has that provide any protection, leaving contaminants to flow into an aquifer.
What Includes Plug and Abandon Operations
When performing plug and abandon operations, operators will prepare the well site for abandonment activities. They take precautions to make sure they can safely work around the well. They will evaluate the site to make sure they have safe access, stability, and solid condition, presence of living organisms, terrain contour, and others. Then, they will remove and salvage available equipment like wellbore casing and tubulars. Stuck tubulars must be removed above the cut using fishing tools. The job is done through the freepoint/backoff or stretching process or by cutting off the tubulars at a predetermined depth with chemical cutting .They will leave the tubulars below the cut in the wellbore. Then, they will place cement plugs in the borehole and test to prevent fluid migration between various formations. Finally, they will cut the upper casing below grade and cap the well before they reclaim the surface to match the surrounding environment. Federal and state environmental regulations govern reclaiming activities.
Is Well Plug and Abandonment a Requirement?
Federal, state, and local regulations are established to prevent future aquifers contamination. Plugging is mainly meant to prevent future contamination and ensure the area is returned to its original state, before any evaluation or drilling processes. Overall, the area must be returned to pre-drilling conditions.