Electromagnetic Wave Resistivity MWD Tool

Abstract

Summary This paper is an overview of the development of a 2-MHz [2×106-cycle/sec] measurement-while-drilling (MWD) resistivity logging tool. This tool uses propagating electromagnetic waves rather than the pseudostatic fields of its low-frequency counterparts. The basic theory of operation is presented along with a discussion of the factors that affect tool response and the compromises that led to the specific embodiment. Field data are presented from which a comparison is made between this tool and wireline tools. It is seen that it is often possible to obtain a direct reading of true formation resistivity, Rt, with this tool.