(92d) Integrated PHA Approach for an Auditable Barrier Management Regime

The Oil and Gas Industry is constantly evolving and increasing in complexity. Operators are seeking new strategies to increase the auditability and connectivity between disciplines and their studies. Barrier management is a developing methodology that is utilised, to systematically establish and maintain barriers so that the risk faced at any given time can be handled. This is achieved by preventing undesirable incidents from occurring or by limiting the consequences should such accidents occur. Barrier management includes the processes, systems, solutions, measures and tools which must be in place to ensure the necessary risk reduction through its implementation. Barrier management establishes an easily communicated risk picture.

Companies are having to look at streamlining methodologies to ensure effective and efficient barrier management techniques.

A holistic barrier management involves the a), the identification of hazards and their barriers, the determination of barrier performance standards, and the monitoring of barrier performance during operations and their continued applicability in an ever changing operational environment. There are various techniques and tools available to safety professionals when considering overall barrier management. However, despite some efforts in the past, there is still no standard methodology on how to practically combine these complex standalone techniques into one easily understood combined barrier model. Techniques such as HAZOP, LOPA, RBI, Bowtie, Alarm Rationalisation, Prestart-up safety audits, and human factors studies are traditionally used to address concerns due to design issues, mechanical integrity issues, process and operations issues and external events. However, these studies are performed in isolation and are rarely combined into one distilled easily understood risk picture. This results in differing competing conclusions from the various studies and a complex risk picture which is not easy for frontlines operations staff to understand and implement.

To address the potential issues of performing these studies in isolation and to ensure the safe operation of hazardous facilities, a formal, systematic and integrated system will be presented. As a sample case, an integrated HAZOP, LOPA approach was developed for a large existing onshore oil and gas facility to address process risks. This integrated approach is presented as an example to illustrate how complex studies such as HAZOP and LOPA were distilled into a pictorial and easy to use bowtie for operations. Bowtie diagrams are often used to communicate a holistic picture of barrier management efforts. They take into account all the various studies undertaken by the differing disciplines. The diagrams give a clear illustration of the relationships between the hazard, the causes of its realisation and its potential consequences. It includes easily understood pictorial descriptions of the control and recovery measures along with barrier degradation issues such as the effect that ageing has on a facility barrier management system.

Additionally, the paper will discuss examples techniques, which are being utilised or being considered for the integration of the degradation of barriers which are not deeply considered in HAZOP and LOPA, such as mechanical integrity, external event and design defects. When combined with the process risks discussed in HAZOP and LOPA a holistic unified risk picture can be presented e.g. the impact of omission of critical inspection and maintenance activities, human error during critical tasks operational activities, failure in ignition control, ineffective emergency response systems. The paper will therefore discuss the impact of deficient assurance activities, design, human factors and the overall process management system.

The paper will demonstrate how an integrated barrier management approach is currently being applied at an existing facility by focusing on integrating HAZOP, LOPA and Bowtie Studies. Potential future improvements to current practice will also be addressed. The paper will ensure that study findings, from various critical studies covering all potential failure mechanisms are clearly communicated via the pictorial bowtie, and provide a clear risk picture to practitioners, operations and management. This methodology results in a highly efficient and auditable workflow.