Thank you very much for your help. Water, for example, is good for concrete. The longer it stays wet the stronger it will be and less chance of cracking. Usually, the water sealer the contractor uses is intended to keep the water in and not to prevent new water from penetrating. For appearance you may want to color it, but that is best done during placement.
Oil is a different story.
It will not damage the concrete, but will create dark unsightly stains that are practically impossible to remove. So, the purpose of the sealer is more to keep it looking good and not to make it last longer. A couple of things that can harm the concrete are acids and sulfates. Sulfates in the soil can damage low quality concrete exposed to very high concentrations for many years, but surface sealers will not protect against that. Lake Worth, Fl.