Analysis of well logs for the detection of coal seams - A case study from Rajbar block of Auranga coalfield, Jharkhand, India

Abstract

Geophysical well logging survey was carried in nine different boreholes in the Rajbar block of Auranga coalfield in the Damodar valley area of Jharkhand, India in order to delineate a number of coal seams, their depth, thickness and lithology.I used a conventional set of logs consisting of Density, Gamma-ray, Single point resistance and Resistivity for the delineation of several unknown coal seams.Lithological interpretation was carried out using Ward's method of hierarchical cluster analysis to decipher the variation of litho-facies of each borehole.Also, agglomerative clustering was used to assign a distinct lithology for each unique interval in the borehole.I found that the interpreted physical properties from each borehole are in good agreement with the range of physical properties obtained from core samples analysed in the laboratory which enhance the reliability of interpreted litho-logs.