Similar to building construction there are different types of O&G projects - wellheads, pipelines, upstream, refinery, production, storage, offshore, etc. I am a civil engineer and was doing buildings initially. When I shifted to O&G the first thing I did was to coordinate with engineering and construction disciplines to familiarize myself to the process. I presume you know how to read plans and understand specs, that would benefit you a lot. We all start at zero and should take each step at a time. Your interpersonal skills would come in handy to liase with experienced team members.