Porosity-Strength Correlation: Failure Criteria from Porosity Logs


R. A. Farquhar, B. G. D. Smart, B. R. Crawford,
Heriot-Watt University


The use of failure criteria is a fundamental requirement in the evaluation of potential wellbore integrity problems. Laboratory testing of sufficient samples to describe the geological column in a well is inhibitively expensive. Conventional analysis is achieved using mechanical properties logs in which compressive strength is determined from dynamic Young’s moduli and estimates of the clay volume.