Case Study of Weak Signals and Confirmation Bias in Drilling Operations

Abstract

Abstract The paper presents a case study of the circumstances leading up to a situation where a supposedly vertical well ended up at 14° before the deviation was detected and a correction could be made. This case study illustrates how a relatively routine activity could end up off the plan, and also highlights the impact of weak signals and confirmation bias on the situation. Process safety has become a focus of attention, with much work done to ensure that organisations are educated and trained in the techniques necessary to avoid catastrophic incidents. Human error has come under the spotlight and "human factors", including non-technical skills, are being included into training programmes, such as well control. However, the language around human factors, and the psychological terms used, such as "cognitive bias", "chronic unease" and "weak signals" are abstract and unfamiliar to the drilling community. Furthermore, limiting human factors training to well control suggests that non-technical skills are only required during abnormal events. Yet, as this case study will show, developing these skills in general brings benefits in avoiding what might be regarded as "normal" non-productive time incidents. By describing a real and very recent wells incident, the paper shows how the same set of circumstances can be investigated from several different perspectives and how different conclusions about root cause can be drawn depending on the agenda of the investigator. There is no doubt that no single perspective fully explains what happened in this incident, and why, but traditionally there is little evidence of a human factors perspective being adopted during incident investigations beyond the use of the label of ‘human error’. The paper will show how, without the benefit of hindsight, the rig team made a perfectly reasonable set of decisions under the circumstances with which they thought they were being confronted. There was evidence in some of the data to suggest that the well was deviating from the vertical, but there were competing pressures on the team for them to disregard the warnings. While there are certain obvious procedural and technical lessons to be drawn from the event, deeper lessons relate to the difficulties associated with overcoming the tendency to see what is expected and the central role played by leaders to support and commit to the time and cost of precautionary actions. It is hoped that the paper will encourage the drilling community to look beyond the apparent interpretations of an event to consider why it was that otherwise sensible people did what they did. There are many incidents of this type from which the community can learn at relatively low cost, particularly focusing on the human factors aspects. Yet, the learning from these incidents, and the training to avoid them will, ultimately, develop the skills that will be instrumental in helping teams identify and react to conditions that might otherwise develop into a catastrophe.