Tools and Techniques for Plug and Abandonment

Abstract

In permanent P&A, establishment of a rock-to-rock barrier is a requirement. There are situations where the annular barrier behind casing is not qualified or there is no annular barrier. Therefore, full access to the formation shall be obtained. Different techniques have been utilized by the petroleum industry such as cut-and-pull, casing milling, and section milling. Some new techniques have been suggested some of which are in use and others are in development. Such techniques include perforatewash-cement, upward section milling, melting downhole completion, and plasmabased milling. This chapter will present these techniques, briefly.

A fault diagnosis method based on low signal to noise ratio vibration measurement for use in casing cutters

“…The role of the casing is mainly to protect the wellbore, seal the oil-vapor-water triplex and provide a flow pipeline for downhole fluids [1,2]. An electric casing cutter is a well repair tool for repairing damaged well casings [3,4]. Casing cutters are highly susceptible to various failures due to factors such as cutting vibrations, greater rigidity of casing materials and high-temperature and high-pressure logging environments.…”