DEFLECTING WEDGE FOR PREDRILLING BRANCH HOLES Russian patent published in 2010 - IPC E21B7/08 

FIELD: oil and gas industry.

SUBSTANCE: invention refers to oil-and-gas well drilling, particularly to branch hole predrilling tools. Said tool consists of a deflecting wedge with a gallery, pivotally connected from below and spring-assisted outside with a substitute which is equipped from below with an anchor packer; the tool also comprises a setting tool in the form of a hollow branch pipe with an upper joint sleeve to connect to a drill stem and a left thread from below to connect to the substitute. The hollow branch pipe from below is equipped with a stopper, while the substitute includes a cylinder, with a piston fixed by millable elements in the top of the cylinder and movable longitudinally relative thereto. The hollow branch pipe above the gallery of the wedge is equipped with upper and lower arresters between which there is a sliding ring provided with a casing in the form of a hollow cup sector with its bottom up.

EFFECT: offered design improves performance quality, and reduces crashworthiness and cost of well construction especially in abnormal geological conditions.

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