Application of inverse filtering to gamma‐ray logs: A case study

Abstract

The application of digital inverse filter deconvolution techniques to seismic data has been routine for many years. More recently these techniques have been extended to natural gamma‐ray logging in order to improve the spatial resolution of the recorded logs (Czubek, 1971; Conaway and Killeen, 1978a,b). Early work in this field (Scott, 1963) involved an iterative procedure which required repeated processing of an entire log data set. Such a technique does not lend itself to continuous on‐line deconvolution of a log while the logging operation is in progress. The inverse digital filter approach, by contrast, is particularly well suited for implementation in a computer‐based borehole logging data acquisition system. Such a system had been developed at the Geological Survey of Canada (G.S.C.) by 1978 and was described by Bristow and Killeen (1978) and Bristow (1977, 1979).