Assessing and Comparing Human Errors in Technical operations in Petroleum Wells using Extended CREAM Technique

Excavating operations are among operations with high risk of accidents. Human errors have been identified as the main reason of such hazardous accidents. The present essay is going to scrutinize human errors type and probability in technical services in petroleum wells focusing on comparing acidizing and cementing operations. The basic and extended CREAM method was applied in this research. Initially, the main tasks and sub-tasks were identified in both operations. Then, control modes, common performance condition, cognitive failure probability were determined. In acidizing operations, 61.63% of the control modes were strategic and 7.69% of the opportunistic mode, while they were 25% and 12.5% in cementing operation, respectively. In acidization and cementation operations, the time of day, number of simultaneous goals and sufficiency of training and experience were considered as factors reducing performance. Furthermore, the cognitive failure probability has been more than 0.005 in 34% of sub-tasks in acidization operation, whereas in cementing, the failure probability has been more than this amount in 50% of the sub-tasks. The strategic control mode has held the highest percentage of control modes. In addition, in investigating the comparison of the more hazardous, the percentage of more strategic control in acidization operation indicates that acidization is safer than the cementation one. Considering the higher probability of cognitive failure under the sub-tasks of cementing operations, the probability of failure in the cementing is higher than that of acidization and is more hazardous. Therefore, it needs to implement some measures for decreasing human errors at these hazardous operations.