Abstract: Based on analyses about the structures and existing problems of integrally retractable alternative cutting element bits, a integrally rotary replacing cutting element bit was proposed. The combination of spring, mandrel and spherical in the structure was adopted to control the orientation of replacable bit .A suit of conveyer utility was used to operate the bit ascent and descent. This design of the bit can overcome some shortcomings such as complicated structure and not reliable performance of drilling tool. It is proved that the drilling efficiency is 10%~50% higher than ordinary wire-line coring drilling tool.

Key words: geological exploration, coring, integrally retractable alternative cutting element bit, structure