Research on the same diameter coring drilling technology used by high-speed turbodrill for deep well

Abstract:

The structural and performance characteristics of turbodrill are analyzed. In the high-temperature and high-pressure and highly abrasive strata of deep and extra-deep wells， turbodrill has basically become the only alternative downhole dynamic drilling tool to increase speed and reduce costs in composite drilling. In view of the exploration and development requirements of deep resources， the advantages and existing problems of the existing turbodrill core-extraction technology are described. In addition， numerical simulation technology is used to analyze and study the influence of drilling fluid flow state on the coring effect in the process of simultaneous coring with turbodrill. It is recognized that turbodrill can withstand high temperature and is suitable for full drilling and coring in deep and extra-deep wells， but its high rotational speed is also easy to cause core wear and rock column spiral in the process of coring drilling. Improving the high-speed single motion performance of the core-drilling tool， lengthening the spiral stabilizer of the turbodrill and using the reverse spiral spoiler are beneficial to reduce the vortex motion at the bottom of the hole and the axial velocity difference between the inner and outer tubes of the core， so as to improve the core quality of the core-drilling tool.