Patent ID: 6606565
Filing Date: 2003-08-12
Classification: G01V

Abstract:
A method of deriving an apparent conductivity log from raw elemental readings from a sonde comprising a plurality of receiver coils, the method comprising:(a) generating at least one digital signal comprising a plurality of frequencies using at least one transmitter; (b) receiving analog responses from the at least one digital signal through the plurality of receiver coils; (c) converting the analog responses from each receiver coil into digital signals by sampling the analog responses by phase and averaging samples of a common phase in a manner such that the resulting average represents a raw elemental waveform that is sampled more finely than the actual sampling rate; (d) raising each raw elemental waveform to several predetermined powers to generate a plurality of powers of conductivity; (e) convolving in depth the powers of conductivity with a plurality of filters, where each power has a distinct filter; and (f) summing the results of all of the convolutions to produce a conductivity log that is substantially free from the effects of adjacent beds and the nonlinear effects of true conductivity.