Learning from the BP Deepwater Horizon accident: risk analysis of human and organizational factors in negative pressure test

According to several seminal investigation reports on the BP Deepwater Horizon (DWH) accident, misinterpretation of a critical test, called negative pressure test (NPT), was a major contributing cause of that disaster. NPT, according to many credible references, is the primary step to ascertain well integrity during any offshore drilling. This paper introduces a three-layer, conceptual risk analysis framework to assess the critical role of human and organizational factors in conducting and interpreting a negative pressure test. This framework has been developed by generalizing the risk assessment model that was proposed by the authors for the analysis of the conducted NPT by the DWH crew. In addition, the application of the introduced framework in this study is not limited to NPT misinterpretation. In fact, it can be generalized and be potentially useful for the risk analysis of future oil and gas drilling as well as other high-risk operations. Analysis of the developed framework in this paper confirms the results of previous studies by indicating that organizational factors are root causes of accumulated errors and questionable decisions made by personnel or management. Further analysis of this framework identifies procedural issues, economic pressure, and personnel management issues as the organizational factors with the highest influence on misinterpreting a negative pressure test. It is noteworthy that the captured organizational factors in the introduced conceptual framework are not only specific to the scope of the NPT. The three aforementioned organizational factors have been identified as common contributing causes of other offshore drilling accidents as well.