Actually, I'm pretty impressed! This will help me with real-time markups in the field on my tablet, which saves me from the double work of having to use my iso's then going back on the laptop to do it all through bluebeam. It has a toolbox with markup stencils. Unfortunately, there's nothing for oil and gas specifically, you'll have to use the plumbing tool kit to markup valves. Five stars if it had toolbox stencils for more pipe and maybe I'm just being able diva. Great app though!