METHOD AND APPARATUS FOR RESISTIVITY MEASUREMENTS

摘要

An apparatus for measuring a resistivity of a formation comprising an instrumented bit assembly coupled to a bottom end of the apparatus. At least one first electromagnetic wave antenna transmits an electromagnetic wave signal into the formation. At least one second electromagnetic wave antenna located on the instrumented bit assembly and longitudinally spaced apart from the at least one first electromagnetic wave antenna receives the electromagnetic wave signal transmitted through the formation. Electronic circuitry is operably coupled to the at least one second electromagnetic wave antenna to process the received signal to determine a resistivity of the formation proximate the instrumented bit assembly.

主权项

1. A system for measuring a resistivity of a formation comprising:
an instrumented drill bit coupled to a bottom end of a bottom hole assembly; at least one first electromagnetic wave antenna located in the bottom hole assembly to transmit an electromagnetic wave signal into the formation; at least one second electromagnetic wave antenna located on the instrumented drill bit and longitudinally spaced apart from the at least one first electromagnetic wave antenna to receive the electromagnetic wave signal transmitted through the formation; and electronic circuits operably coupled to the at least one second electromagnetic wave antenna to process the received signal to determine a resistivity of the formation proximate the instrumented drill bit; wherein the at least one second electromagnetic wave antenna comprises a plurality of coil receivers mounted circumferentially around the instrumented drill bit to detect a radial resistivity of the formation at the instrumented drill bit.