Panel interviews are common with Chevron and it is not unusual to have second or even third interviews. They want to make sure they are hiring the right candidate. The panel members all take turns asking questions. One question usually leads into the other. The atmosphere was very informal but they try to ask questions to determine technical (functional) skills, interpersonal skills, and decision making. Chevron really wants candidates and employees that follow rules and will not do anything to jeopardize their reputation so interviews are set to weed out candidates that may not fit in their corporate culture. Believe it or not, honesty and integrity is a big part of the culture even though it is a large multinational company.