Abstract: The present invention provides a tool assembly system for use in a single trip downhole operation in which an alloy plug/seal is set and then at least partially milled through. The system comprises a tubular chemical heater with a mill that has at least one flow port and a tubular mandrel arranged on the outside of the heater at up-hole and down-holes ends of the heater respectively and whereby the heater is removably retained within the mandrel so that the mill can be subsequently repositioned to work on the mandrel once the alloy plug/seal has been formed. The present invention also provides an associated method of forming an alloy plug/seal and milling it at least partially through in a single trip.

Abstract: A multi-trip method of repairing a leaking annular seal located within an annulus that encircles an oil/gas wellbore tubular body, examples of such seals including annular packers or cement seals. The method comprises providing deflector within a wellbore tubular body adjacent to one or more openings in the wall of the tubular body. Alloy beads are then deployed downhole via the tubular body so that the alloy beads are deflected via said openings into the annulus where they accumulate on top of the annular seal. A heating tool is then operated to heat the alloy within the annulus to form an alloy plug above the annular seal. The present invention also provides various pieces of downhole equipment for use in the repair method of the invention.

Abstract: A single trip method of repairing a leaking annular seal located within an annulus that encircles an oil/as wellbore tubular body, examples of such seals including annular packers or cement seals. The method comprises providing deflector within a wellbore tubular body adjacent to one or more openings in the wall of the tubular body. Alloy beads are then deployed downhole via the tubular body so that the alloy beads are deflected via said openings into the annulus where they accumulate on top of the annular seal. The alloy is then heated to form an alloy plug above the annular seal. The present invention also provides an annular seal repair tool assembly for use in the repair method of the present invention.