Petroleum, gas or geothermal driling apparatus

Abstract

The invention relates to a petroleum, gas or geothermal drilling apparatus comprising a central tool and a coaxial bit, wherein the central tool is driven by the rotor of a bottom engine which is fed by the drilling mud and wherein the bit is driven from the surface by the rods of a drill gear which is part of a rotary system, these same rods subjecting the apparatus to an axial load. It is characterized in that there is a prismatic connection between the stator (4) of the bottom engine and the base (5) of the bit, which allows the relative axial displacement of the two tools, and that a spring (6) is interposed between the stator (4) and the base (5) in such a way as to form a constraint on the stator when the central tool tends to fall behind in respect to the bit during their respective forward movements, so as to control the relative axial displacement of the two tools and to distribute between them, as a function of the displacement, the axial load to which the apparatus is subjected. Used in the drilling material industry, namely for petroleum, gas or geothermal drilling.

Dependencies are inferred from the claim text.