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The effectiveness of non-regulated HSE cases in the drilling industry

Ali, Karim Ali Yousef Hassa


Karim Ali Yousef Hassa Ali


Stephen Pace

Peter, Prof. Waterhouse


Background and Purpose
The safety case regime, as a control measure to major accident hazard, was introduced to the oil and gas industry, three decades ago, following the Piper Alpha disaster. It appeared that safety cases had not passed the cost-benefit analysis, and its effectiveness had not been ascertained. This study investigated the effectiveness of non-regulated safety cases, within one of the oil and gas drilling companies, by determining its level of utilisation and examining its impact on the risks of major accidents and other rig incidents.

The study design was cross sectional, retrospective and experimental. A questionnaire was administered electronically, after it had been tested and its validity and reliability had been assured, to five rig supervisors of 10 rigs that owned safety cases. Incidents were extracted from the company incident logs. The risk of major accidents and other rig incidents were compared and analysed before and after the introduction of safety cases, and against a control group.

Out of 50 rig supervisors, 42 (84%) completed the questionnaire. The majority of the respondents indicated that they did not perceive a rig safety case as the most effective tool in reducing major accident risks; however, they agreed that safety cases were still required. Moreover, the introduction of safety cases to six rigs did not reduce the risk of major accidents or other rig incidents.

Discussion and Conclusions
The level of utilisation of non-regulated safety cases was evaluated to be below average. Furthermore, the evidence showed that safety cases did not reduce the risk of incidents. Conversely, the majority of the respondents indicated that safety cases were still needed in the drilling industry. The aim and objectives of the study were achieved; four hypotheses were tested, and recommendations were put forward for the company management and future researchers.


Ali, K. A. Y. H. (2019). The effectiveness of non-regulated HSE cases in the drilling industry. (Thesis). University of Hull. Retrieved from

Thesis Type Thesis
Deposit Date May 31, 2019
Publicly Available Date Feb 23, 2023
Keywords Physical sciences; Occupational health
Public URL
Additional Information School of Mathematics and Physical Sciences, The University of Hull
Award Date Jan 1, 2019


Thesis (2.8 Mb)

Copyright Statement
© 2019 Ali, Karim Ali Yousef Hassa. All rights reserved. No part of this publication may be reproduced without the written permission of the copyright holder.

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