Pros
Great camaraderie with lots of fellow coworkers in a very male dominated industry. Lots of airline, hotel and credit card points can be obtained. You will be paid straight time overtime as well if you are billable over 40 hrs/week which is not common in other salary positions. You will have the opportunity to travel around the US and potentially out of the country. You can learn a lot about the energy industry. You are never stuck in an office for to long.
Cons
LOTS of travel and very long days (12 hour days) when on a job. Consider traveling 3 weeks every month from Monday - Friday. The travel doesn't slow down as you climb the ladder. In fact, you end up having to travel more in order to offset your higher hourly bill rate. Also the travels are mostly to remote areas where there is little to nothing to do which can also affect your eating habits and make it difficult to maintain a healthy lifestyle. Management was difficult to work for as they would constantly schedule you on jobs that would keep you away from home on a regular basis. Also, they were not very good at showing appreciation for a job well done. Long work days and at times in some very dangerous work environments. You can easily get burned, cut and various other injuries if you are not careful. You also work outdoors on tall smoke stacks which is not ideal for those who do not like heights. Work can be fairly labor intensive depending on the particular job you are on. Once you can learn to run a mobile laboratory, then most of your work will be inside a trailer but the travel doesn't stop which makes it difficult to keep commitments. Once you enter the industry, you are pigeonholed in that field which makes it difficult to obtain jobs outside of the industry.