If compared to Well Design, Abandonment Design has the additional challenge of having to work on equipment that has been in the ground for years or decades, and therefore may be damaged; very often, there are also missing information on the well status and characteristics.
In the past years, projects were done with a fish in the well, or where pumping was very difficult, and with annular pressures from unknown sources. The way the project is tackled is to obtain as many information as possible on the status of the well and previous operations, identify the missing data and therefore the unknowns and the possible risks associated with those, and identify an operational plan of action in steps (up to thirty per abandonment from experience), making barrier diagrams for each step. This ensures that all the necessary barriers are in place at every moment, and that backup plans are ready to be implemented if needed.
Welltodrill di Valentina Gagliardi's approach is therefore structured, transparent and trackable with a risk register that develops along each planning stage.