• The human component figures prominently in Apache Corporation’s well-documented drive toward developing an automatic rig-based drilling advisory system. The foundation has been laid with the installation of data aggregation boxes on 21 Apache rigs, which integrate seamlessly with the rig’s electronic drilling recorder to run physics-based models built around a basic Bayesian probabilistic network. The system is able to quickly pinpoint sensor, equipment and process faults, as well as run real-time hydraulics and torque and drag models to enable decision-making at the rig site, rather than on the basis of interpretations from real-time operations centers.