Hydraulic Whipstock Anchor

Abstract

A whipstock anchor is hydraulically set and locked in the set position. Release occurs with a pull induced component failure that relieves hydraulic pressure that allows the slips to retract. Release can occur with a remotely actuated circuit that burns a retainer for a piston whose movement opens a vent or initiates a chemical reaction to undermine a lock ring. Movement of a single cone or opposed cones extends the slips. The cone angles being different (cone angles do not have to be different, it is preferred to have the slip angles different) adds a skew to the slips and positions the top of the whipstock against the tubular top in a horizontal run. A bottom cap is removable to convert to setting by set down weight or to attach a hydraulically operated packer below the slips. Slips can be extended with radial movement of pistons.

Description

FIELD OF THE INVENTION

[0001] The field of the invention is hydraulic anchor assemblies for whipstocks in borehole use and more particularly anchors that release in a variety of ways, or cock the whipstock or that can be modularly built to optionally add setting capability with setting down weight or be reconfigured to add a hydraulically actuated sealing functionality to the anchor.BACKGROUND OF THE INVENTION

[0002] Whipstocks are long tapered ramps that are secured in a tubular string to guide a mill assembly laterally to make an exit through the tubular wall for the start of a lateral bore. The taper angle is gradual, in the order of about 1-3 degrees. The ramp is typically oriented with a bottom hole assembly so that the ramp faces the direction of the desired lateral. In some instances there can be a need to have the lateral exit in a downward direction off a horizontal bore. In such cases it is advantageous to ensure that the top of the whipstock is pushed against the top of the h...

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