SPWLA Glossary

A well log of temperatures recorded within the borehole, utilizing a temperature-sensitive element exposed to wellbore fluid. The temperature survey is often used to locate permeable gas producing zones in empty holes, and to locate producing or injection intervals, acid treatment in tervals, and casing leaks, crossflows, etc. in cased holes. The differential temperature survey, recorded with either one or two temperature sensors, records the rate of change in temperature with respect to depth. It is very sensitive to small changes in temperature resulting from small thermal events.