Drill with logging facility - cable led down inside drill string has non-rotating bottom probe

摘要

Drill combined with logging facility consists of a power rotated bit at the bottom of a forcibly located and fed drill rod string and an electric cable which is so coupled to the locator system that it does not rotate during the drilling and logging action. The cable runs down inside the rods close to the bit and is anchored so that it can be introduced together with the rod string. A probe at the bottom end of the cable connects directly to the bit and thus receives signals transmitted by this. The signals are led to the surface recording and display facility. The probe should be so anchored as not rotate during drilling.