  Oil and gas drilling is based, increasingly, on operational technology, whose
cybersecurity is complicated by several challenges. We propose a graphical
model for cybersecurity risk assessment based on Adversarial Risk Analysis to
face those challenges. We also provide an example of the model in the context
of an offshore drilling rig. The proposed model provides a more formal and
comprehensive analysis of risks, still using the standard business language
based on decisions, risks, and value.
