Just thought id post this15 Nov 2015 14:40
plugging and abandoning (P&A) of oil and gas wells that are no longer economically viable for production, or which have wellbore issues that require closure, has historically been conducted as an afterthought in the oil and gas production business. Production wells that can no longer be used must be plugged to prevent the oil and gas reservoir fluids from migrating uphole over time and possibly contaminating other formations and or fresh water aquifers. A well is plugged by setting mechanical or cement plugs in the wellbore at specific intervals to prevent fluid flow. The plugging process usually requires a workover rig and cement pumped into the wellbore. The plugging process can take two days to a week, depending on the number of plugs to be set in the well. The P&A work takes capital to complete and provides no return on the investment for the oil companies. Most wells are plugged at the lowest cost possible following the minimum requirements set forth by the oil and gas regulating agencies