APPARATUS TO FIX MULTIHOLE BOREHOLE Russian patent published in 1995 - IPC

FIELD: drilling. SUBSTANCE: apparatus has casing string of main hole with window for casing string of auxiliary hole, casing string of auxiliary hole, pattern flange, cover plate with hole for casing string of auxiliary hole. The cover plate is located on outer surface of casing string of main hole and is rigidly connected with it. In the case part of inner surface of the cover plate is conjugated with outer surface of pattern flange, mounted flush with inner surface of casing string of main hole and connected wit upper part of casing string of auxiliary hole. Casing string of auxiliary hole is provided with side longitudinal guides. EFFECT: simplification of design, increase of reliability in work allows to decrease ratio of diameters borehole hole and casing string hole more than twice as much. 1 dwg