Use of Computers To Perform Old Log Analysis

Abstract

Summary In the past, old gamma ray neutron (GRN) (1940's to 1960's) and old electric (E) logs were not widely used for detailed log analysis because performing this task accurately is manpower intensive. Recent developments in computer hardware and software have made it feasible to digitize and analyze old logs to obtain more accurate reservoir parameters for fields developed from the 1930's to the 1960's before modern logs were available. This paper describes a computer-based method to rescale old GRN and E logs efficiently, then perform shale volume, effective porosity, bulk volume water (BVW), and water saturation calculations. This method leads to more accurate reservoir characterization and reserves determination. Using the computer simplifies this task and reduces the cost enough that old fields may be studied that otherwise might not be economically feasible to study.