Blowout preventer (BOP) risk model to assist critical decisions in offshore drilling
The BOP is a critical safety system of an offshore drilling rig, as shown in the 2010 Macondo accident. A challenge for the oil and gas industry is to decide what to do when the BOP is failing. Pulling the BOP to the surface during operations for inspection and testing is a costly and timely operation. Many of the potential failures are not critical to overall safety as multiple levels of redundancy are often available. Scandpower and Moduspec, both subsidiaries of Lloyd’s Register, have developed a BOP risk model that will assist the industry make the pull or no pull decisions. Scandpower’s proprietary software RiskSpectrum is used for the modelling. This software is used for equivalent decision support in the nuclear power industry, where the risk levels of total nuclear power plants are monitored live by operators in the control rooms. By modelling existing BOPs and their submerged control systems, and using risk monitor software for keeping track on the status of the BOP subsystems and components, the industry is able to define the real-time operational risk level the BOP is operating at. It, therefore, allows the inclusion for sensitivity modelling with possible faulty components factored in the model. The main task of the risk model is to guide and support energy companies and regulators in the decision process when considering whether to pull the BOP for repairs. Moreover, it will help the communication with the regulators, since the basis for the decisions are more traceable and easier to follow for a third party.