HIGH RESOLUTION ARRAY INDUCTION TOOL

摘要

A coil array for high resolution logging (Figure 3), comprises a transmitt er (T), a fl receiver set positioned at a distance from the transmitter (UR), a nd a second receiver set positioned at a second distance from the transmitter (LR ), and a method for deriving a conductivity log from at least one induction well lo g that comprises a plurality of depth samples (Figure 4), comprising the steps of raising each depth sample of the conductivity signal to several predetermined powers to generate a plurality of powers of conductivity, convolving in depth the powe rs of conductivity with a plurality of filters, and summing the results of all the convolutions to produce a conductivity log that is free from the effects of adjacent beds and the nonlinear effects of true conductivity. The apparatus for measuring the resistivity, (Figure 2), of an earth formation penetrated by a borehole, comprising at least one transmitter energized by a time varying periodic voltage, one set of receivers generating a receiver voltage, with an analog to digita l converter that periodically samples the receiver voltage at a predetermined sampling rate and outputs a digitized voltage signal, (Figure 2), and a computer processor that receives the digitized voltage signal, with a set of N accumulators that collates and averages successive sets of N samples from the A-D converters and outputs a set of N averages.