Do you know what you need, or do you know what you've got?
Successful P&A planning means addressing key questions including lithology, permeability, pore and fracture pressure, fluid type in overburden and reservoir, column pressures, cement quality, cement distribution, and formation squeeze. It means understanding fluid commingling and risking the potential consequences, including near-wellbore fracturing of weak zones and the lateral escape of hydrocarbons via permeable overburden rocks.
A well can't be adequately described for efficient and assured P&A by compiling an overview of information from final well reports, comp logs and other historic sources of geological and engineering information. Cost efficiency and ALARP risk management requires a complete reinterpretation of each well using tools designed to generate clear answers to the key questions above.