My review pertains only to the "Downstream" part of the business. Upstream is a whole different world.
1. Job security is NOT what you might think it would be in the oil business. There are frequent reorganizations and downsizings in the Downstream and in "support functions". If you care about long term employment stability, be careful about working at Chevron if you are in a discipline that is not core to the day-to-day operations of the company . . . there is a tendency for there to be "flavors of the year" in the various business units as leaders come and go . . . e.g., emphasis on being "Marketing led" this year, "Procurement led" the next, and "Logistics led" the next . . . and as these flavors come and go, there is upsizing and downsizing accordingly within these disciplines.
2. It is almost impossible to get important decisions made; upper-middle managers seem to be rewarded for NOT making risky decisions, so they waffle and stall rather than take action. On any given relatively straightforward project, there will be a way-too-big project team, a way-too-big group of decision makers, endless meetings, and endless revision & recycling of PowerPoint documents for internal consumption.
3. Physical office space is not the greatest . . . main campus buildings in San Ramon are dark and cluttered. . . Houston's offices are sterile and inorganic.
4. While safety must be paramount in operations and field settings, there is an obnoxious and irritating emphasis on personal safety even for office workers. Of course one wants one's employer to be concerned with your health and well-being, but at Chevron it goes over the top to a level of pure ridiculousness. All meetings start with "safety moments" that can go on and on . . . all office-based employees write annual "safety commitments" which are posted on their office doors . . . there are office ergonomic inspections . . . mandatory use of ergonomic software that enforces breaks that'll pop up at inopportune times . . . an idiotic and insane and cumbersome "Loss Prevention System" where there is a formalized process to assess adherence to safety procedures for such matters as "heating food in the microwave" to "walking to your car" . . . If only the shareholders knew how much time was wasted on such pursuits!
5. As in any large corporation, there is definitely favoritism not rooted in meritorious performance. Certain "favored children" are deemed to be incapable of doing any wrong and are put on the fast track; certain individuals treat their subordinates inappropriately but senior management is either unknowing or oblivious because these same individuals "manage up" very well. When a "level 2" manager is assessing performance of a "lower level" manager, subordinates of the lower level manager are seldom approached for feedback.
6. Outcomes of performance reviews (done through "forced ranking" sessions amongst managers at each level in the hierarchy) are often as much (or more) dependent on the supervisor (i.e., his or her personality, status, reputation, forcefulness, persuasive ability) than on the employee.
7. You will need to decide for yourself whether you want to work in an industry that is not exactly beloved by most members of the general public. A lot of the dislike of the petroleum industry is undeserved, but nonetheless there is that taint.