Its not guessing really, there are ways to do it...however, it does take considerable attention and what people gloss over is that most folks dont want to pay attention to their securities. Thats fine, they dont have to, and indexing is a fine way to do just that while receiving a respectable return. Just like medicine different personalities are more inclined to certain styles of investing. Whats enjoyable for me is not for thoracic guy.
As an aside, CVX is the least integrated of the majors, if you were to pick one for stability and dependability it should be XOM. CVX profits are more tied to crude prices than XOM or BP even (actually quite diversified). Their shares may bounce more because of that when/if prices go up in the future but its true. You think prices are low now wait til next quarter after all the proven reserves values are written down and marked to market. BRK on the other hand is a good index fund proxy, and in the future one would think there will eventually be some massive spinning off or dividend payments. Energy companies are an interesting proposition right now. One has to consider that we are in the midst of a secular decline in their ability to continue as profitably as before. Fracking is becoming easier, can be turned on the second prices go up (lots of capped wells), more efficient in cost/production and when deployed worldwide we'll be swimming in oil. On the other side of the coin technological progress and an eye to environmental cost offsetting will not go away. ICE efficiency will increase as it has, hybrids will become more of the proportion of vehicles and electric vehicles will continue their ascendancy to mainstream. Obviously, this will not happen overnight but over the course of decades and there is still money in the oil majors but the future outlook is less bright than in decades past.