Bit for drilling wells and associated drilling method

摘要

A bit for drilling wells has a front face with radial blades having cutting elements distributed around the front face. A space for forming a core is situated at the center of the front face. A cavity is provided for evacuating the core towards a periphery of the bit. At least a portion of the cavity is situated between adjacent blades. The cavity is delimited by two lateral surfaces and a clearance surface set back with respect to the front face, and the cavity is open in a direction opposite the clearance surface. The bit may be used in methods for drilling wells and makes it possible to rapidly drill wells of great depth in all types of rock without the risk of clogging.

主权项

1. A bit for drilling wells comprising:
a front face, a plurality of radial blades provided with cutting elements, the blades being distributed around the front face and being arranged on an external annular crown of the front face, a space for forming a cylindrical core, the space being situated at the center of the front face, a cavity for evacuating the cylindrical core without crushing said cylindrical core towards a periphery of the bit, a majority of the cavity being situated between two adjacent of said blades, the cavity being delimited by two lateral surfaces and a clearance surface set back with respect to the front face and the cavity being open in a direction substantially perpendicular to the clearance surface along a substantial entirety of a length of the clearance surface, and drilling mud feed channels, each of the channels opening onto the front face, wherein one of said channels opens into the cavity and is suitable for facilitating the evacuation of the cylindrical core towards the periphery of the bit, without crushing said cylindrical core.