Interpretation Of Electric And Gamma Ray Logs In Water Wells

A typical inexpensive logging program for water wells consists of a Normal or single-electrode resistivity, the SP and, sometimes, gamma ray measurements. Some of the principles underlying the analysis of these logs are reviewed. The usual logging situations are classified into three groups and simple interpretation procedures are outlined for each. Much useful information is provided by these records, especially when they are supplemented by the bit penetration rate and other data. The logs can solve many common ground-water problems. Those, and the ones that they cannot solve, are reviewed.