Concentric simutaneous casing drilling tool

• Main Authors: LIU RUOLONG, ZHAO JIANQIN, WANG YONG
• Format: Patent
• Language: Chinese; English
• Published: 21.11.2012
• 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 relates to a concentric simutaneous casing drilling tool, which solves the problem that the existing drilling tool is complex in structure, difficult to manufacture and assemble, small in transfer torque, and easy to damage. A centralizer (1) is provided with first and second grooves (22, 21) which are opposite fan-shaped grooves formed by a central angle on an end face circle of the centralizer. Side walls of the fan-shaped grooves are planes or curved face sections plus plane sections. First and second reamer bits (4, 9) are provided with first and second shoulders (17, 18) respectively. The first and second shoulders are located at different ends of the reamer bits and projected in the reamer bits. Transfer torque faces (28, 27) of the first and second shoulders are planes which are matched with the side walls of the planes on the grooves of the centralizer. When the drilling bit rotates clockwise and the first and second shoulders are completely in the first and second grooves of the central