Ardyne Holdings Limited

Read Cased Hole Limited

David Stewart

James Linklater

Alan Fairweather

George Telfer

Lukas David

James Aitken

Method of removing casing from a well, in which an annulus between the outside of the casing and the inside of a surrounding downhole body is at least partially filled by debris, the perforated section of casing is washed in casing lengths shorter than the perforation length and an attempt made to pull the casing after each shorter length is washed. If the casing is free after washing only a shorter section of the perforated section of casing then it can be recovered and saves the washing time. A bottom hole assembly is described which includes a downhole power tool to exert a greater force to pull the section of casing between washing steps.

In or relating to well abandonment and slot recovery

A downhole actuator () includes a piston () within a chamber () on which fluid can act on either side to hydraulically activate the actuator. A hydrostatic equilibrium device () and a valve () are mounted around the hydraulic actuator. With a radial port () of the hydrostatic equilibrium device closed and the valve closed to seal the string, pumping fluid through the string operates the actuator. Pressure overbalance prevents movement of the piston (). The radial port () is opened to drain fluid from the string until equilibrium is reached with the annular volume and the piston () can be moved.

Or relating to well abandonment and slot recovery

A method of recovering casing from a wellbore in which: a logging tool is run to an estimated stuck point of the casing through the central bore of the casing spear and casing cutter; the casing spear is attached to the casing and tension applied so that logging can be performed over a length at an estimated stuck point both with and without tension to provide the verified stuck point; and the casing cutter is positioned relative to this to cut the free casing; and the spear used to remove it. The method can be performed on a single trip. Embodiments include incorporating a packer to circulate fluid during casing cutting; a disconnect, anchor mechanism and motor to allow use of a motor to operate the cutter; and a Down Hole Power Tool with a method of establishing the required force to recover a length of stuck casing.

Well abandonment

A downhole casing cutting and removal assembly () and method of use thereof, the assembly comprising a work string () with a cutting mechanism () and plurality of resettable anchor mechanisms (B-D). The arrangement allows a test pull to be made following the cut by an anchor mechanism closer to the upper end of the cut casing section than an anchor mechanism (B-D) located close to the cutting mechanism. Time is thus saved by not having to raise and lower a single anchor mechanism (B-D) between the cutting position and the upper end of the cut casing section to undertake a test pull.

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Aberdeen, United Kingdom

David Stewart