DEVICE FOR WELL DRILLING IN INCOMPETENT AND DECAYED ROCK ALONG WITH WELL CASING Russian patent published in 2005 - IPC

FIELD: mining industry, particularly for drilling expendable, water-intake, drainage and other technical wells in decayed and incompetent rock, for instance for creating drilling assemblies for performing well drilling and simultaneous casing thereof.

SUBSTANCE: device has drilling and casing strings, shoe with centralizer, rock cutting tool, guiding member and whipstock provided with supply channels. Guiding member has eccentric transversal rectangular groove. Groove has lower part with taper equal to that of whipstock tail and extending for eccentricity value defined as difference R_w-R_ct, where R_w is well radius, R_ct is cutting tool radius. Whipstock is arranged in eccentric transversal groove of guiding member and may be displaced in axial and horizontal directions. Axis of whipstock supply channel adapted for flushing agent feeding to well face extends at an angle to well face axis and to well axis.

EFFECT: increased operational reliability within wide range of mechanical-and-physical rock properties, increased speed of bringing thereof from transport position into working position and vise-versa with the use of production-run rock cutting tool.

4 cl, 1 dwg