Human Reliability Analysis in a Test Plant in the Pre-Operational Stage

Human factors have a significant impact on any complex engineering system throughout its lifecycle, whether during design, commissioning, operation, maintenance, or decommissioning. Even autonomous systems are not entirely immune to human impact, as they rely on human intervention during development, maintenance, and software troubleshooting. As such, ensuring human reliability in these systems is becoming increasingly essential to avoid losses (MATURANA, 2017).

Studies on Human Reliability began in the nuclear industry, and over time other sectors with significant risk associated with their operations intensified their practices to better manage human factors, such as the oil and gas industry.

In the oil and gas sector, recognizing human factors as an important aspect of operational reliability grew significantly since the 1970s. The Piper Alpha disaster in 1988 in the North Sea was a major turning point that highlighted the need to understand and mitigate risks associated with offshore activities. This led to stricter regulations and the adoption of systematic approaches to manage human factors in these operations (THEOPHILUS, 2017).

Human Reliability is defined as the probability of a person successfully performing an action as required by the system within a given time frame without causing harm to that system (HOLLNAGEL, 1993). Several Human Reliability Analysis (HRA) methodologies exist, including:

- Systematic Human Error Reduction and Prediction Approach (SHERPA): A qualitative methodology that analyzes tasks to predict and reduce human errors. It divides tasks into categories and identifies potential errors associated with each. It's widely used in design projects and procedure analysis to increase reliability and safety.

- Technique for Human Error Rate Prediction (THERP): A quantitative methodology that uses fault trees to predict human error rates in complex systems. It breaks tasks into smaller steps, assigning probabilities of error to each step to calculate the system's overall reliability. It's often used in high-reliability environments like nuclear power plants and critical operations.

- Standardized Plant Analysis Risk - Human Reliability Analysis (SPAR-H): A quantitative methodology primarily used in the nuclear industry to analyze human error risks. It considers eight Performance Shaping Factors (PSF's), such as complexity, training, and time available, to calculate the probability of error in various operations. This approach, with its PSF's based indicators, facilitates comparing results across different scenarios.

- Petroleum Human Reliability Analysis (PETRO-HRA): A methodology adapted from SPAR-H for the oil and gas sector. It evaluates tasks related to drilling, production, and refining operations, considering factors like hazardous environments and complex processes. The aim is to identify risks of human error and implement strategies to mitigate them.

- Analysis of Pre-Accident Operator Actions (APOA): A methodology focusing on operator actions before an accident or incident. It analyzes operator behavior in risk scenarios to identify potential failure points. The approach helps understand how operators can avoid accidents through appropriate procedures and proactive interventions.

During the design phase, Human Reliability Analysis is crucial to ensure that processes and facilities are developed to minimize the risk of human failures, improving aspects such as risk identification, ergonomics, human-machine interface, training and procedures, as well as simulating human error scenarios and assessing their impact on the operational process. By focusing on human factors during the project phase, it is possible to achieve greater process efficiency and safety while reducing costs associated with failures and rework (RAMOS, 2021).

The design of a test plant involves stages ranging from the informational phase, with a literature review and understanding of the project proposal, through the conceptual phase, the detailed phase, with preliminary system architecture, to the final project delivery. In each of these stages, different aspects related to human factors are structured, and the responsible team must decide when to begin applying human reliability analysis methodologies.

The test plant that will be the object of this study aims to support qualification and reliability testing for integrated drilling, completion, and processing systems in the oil and gas sector. It will conduct single-phase flow tests (liquid or gas) at high flow rates, high temperatures, and high pressures, both in steady-state and transient regimes, as well as leak tests, hydrostatic tests, pneumatic tests, and functional tests.

The main product of this test plant will be to verify the operational performances, levels of availability, reliability, operational limits, and useful life of integrated systems and equipment, such as chemical injection valves. To conduct these tests, the operational team must perform its activities with minimal human error. To achieve this, the performance-shaping factors, including organizational, individual, and technological factors, should be considered in applying human reliability analysis methodologies.

Given the wide range of human reliability analysis methodologies available, deciding which will be used is crucial to ensure results aligned with the specificities of the operational process and coherent with the project's current phase. Thus, the objective of this study is to investigate the applicability of available human reliability analysis methodologies during the early stages of the project.

REFERENCE:

¹ KIRWAN, Barry . A Guide to Practical Human Reliability Assessment. Boca Raton: FL CRC Press, 1994.

² THEOPHILUS, Stephen C. et al. Human factors analysis and classification system for the oil and gas industry (HFACS-OGI). Reliability Engineering & System Safety, v. 167, p. 168-176, 2017.

⁵ Health and Safety Executive. Review of human reliability assessment methods (RR679). Available at: Review of human reliability assessment methods RR679 (hse.gov.uk). Accessed on: 03/13/2024.

⁶ MATURANA, M. Consideration of human reliability in the design of complex systems: development and application of TECHR. [Thesis (Doctorate), Polytechnic School of the University of São Paulo.], 2017.

⁷ RAMOS, Marilia et al. Human Reliability Analysis for Oil and Gas Operations: Analysis of Existing Methods, 2021. https://www.researchgate.net/publication/354949856_Human_Reliability_An…

⁸ HOLLNAGEL, Erik. Human reliability analysis. Context and control, 1993.