Dual-torque transmission concentric tube-following drilling tool

• Main Authors: LIU RUOLONG, ZHAO JIANQIN, WANG YONG
• Format: Patent
• Language: Chinese; English
• Published: 10.04.2013
• Subjects: EARTH DRILLING; EARTH DRILLING, e.g. DEEP DRILLING; FIXED CONSTRUCTIONS; MINING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR ASLURRY OF MINERALS FROM WELLS

The invention discloses a dual-torque transmission concentric tube-following drilling tool. The problems of low transmitted torque, difficulty in machining and short service life of the conventional drilling tool are solved. A centralizer (1) is provided with two holes parallel to an axis, and the holes are in movable fit with first and second vertical shafts (2 and 9) of first and second broaching drill bits (4 and 7) respectively. The first and second broaching drill bits have cambered sections. The opposite planes of the broaching drill bits are in sliding fit. The first and second vertical shafts are connected with the centralizer (1) through first and second traverse pins (10) respectively. First and second grooves (11 and 12) are formed in the end face of the centralizer (1), and are opposite fan-shaped grooves in the end face circle of the centralizer (1). The first and second broaching drill bits (4 and 7) are provided with first and second convex shoulders (3 and 8) respectively. The projections of t