Plugging and abandonment (P&A) is the largest category of decommissioning expenditures, representing 40–44% of the total investment. If the well operator performs P&A inadequately, results may include water flows, gas or oil seeps from the seabed, or underground crossflow between formations, with a huge effect on the environment and marine life. This paper presents current advances in the development of a plasma-based milling tool and its use in casing-section milling for P&A.
Introduction
Only 7% of existing North Sea installations have been decommissioned, which creates an enormous opportunity for companies engaged in such a business. Naturally, operators worldwide are seeking effective solutions that would cut the massive expenses of decommissioning.
Each P&A job depends on well construction, well location, production history, casing condition, and many other factors.