The oil business has always had up, then down cycles. During the down cycles people get laid off - a fact.
If your lucky enough to stay with Chevron for 20, or 30 years this won't be the last down turn you see. If this volatility is too much for your nerves, you better get out now!
Frankly, I'm tired of seeing all these posts about mismanagement, or nepotism as the root cause of this companies problems.
Oil prices have dropped over 70% - there is your root cause for the layoffs.
Stop your whining and blaming others. Instead start thinking about what you are going to do for you and your family if you get laid off.