Operational Risk: Stepping Beyond Bow-Ties

Abstract

Abstract This paper presents the Multiple Physical Barrier (MPB) approach to operational (or process) risk that was developed by Argonne National Laboratory with the help of key collaborators from the upstream oil and gas industry. This approach begins with a comparison to the “bow-tie” technique that is commonly used in the industry for identifying operational (or process) risk. Bow-ties identify a variety of different types of barriers and help communicate safety principles that link causal factors and subsequent actions to a specific event – such as a loss of well control event. Bow-tie barriers commonly include equipment, processes, plans, methods, and sometimes people, with their know-how and experience. However, by narrowing the focus to physical barriers (e.g. the source of operational risk) as is consistent with the NORSOK D-010 Standard, and by developing “success paths” that enable each barrier to perform its “safety function,” the MPB approach is demonstrated to step further toward a systematic approach to operational risk management. Additionally, this approach can be seen to help guide operational process design as well as lifecycle management. To demonstrate the versatility of the MPB approach, several applications have been selected that highlight how operational risk can be systematically identified and communicated in different offshore applications: Drilling, including an operational risk comparison between conventional drilling and Managed Pressure Drilling; Completions, installing and de-installing production packers, a barrier that highlights the life-cycle aspect of the MPB approach; and Coiled Tubing Workovers, a risk based design diagram for ensuring that barriers are in place to ensure a successful operation. By making a clear distinction between physical barriers and success path components (including human actions, processes, and plans), the MPB approach adds systematic clarification for understanding and characterizing risks in a direct manner. The MPB approach also enables the identification of chains of causality and builds important steps toward enabling risk quantification. As such, the MPB approach provides a direct and systematic approach for assessing and communicating risk, as well as helping operations to be successful.