Despite the Oil Industry efforts in improving safety, it still presents a high rate of serious accidents, many involving human error. Human Failure Events (HFE) can be identified, modeled, and quantified through Human Reliability Analysis (HRA). The Oil Industry commonly analyses process safety focusing on technical barriers, and therefore it could benefit from Human Reliability assessment. Phoenix methodology is HRA method that uses a human response model that relates the Crew Failures Modes (CFM) to context factors - Performance Influencing Factors (PIFs). Based on Phoenix CFMs and PIFs, two refinery accidents were analyzed: the BP Texas City (2005) and the Chevron Richmond (2012). The analysis consisted on the construction of the accident timeline; identification of the HFEs; categorizing them as one of the CFMs; and analysis of the PIFs. This article highlights and illustrates the relevance of investigating the potential impact of human error in the Petroleum industry.