Devices for drilling branched wells

摘要

A device for drilling lateral boreholes from a cased parent well comprises selecting and coupling means adapted to cooperate with a deflection unit placed within the parent well. The selecting and coupling means are mounted at the lower end of an extension unit formed by interassembled tubular elements. The upper end of the extension unit is rigidly fixed to a suspension swivel within the wellhead and at least one slip joint is interposed between two tubular elements. The internal diameter of each tubular element is such that a drilling packer can be housed within the tubular elements.