I have a small refinery area on my layout which incorporates two Colber oil wells, an architect's model of a refinery catcracker and three oil storage tanks.
This area is on the rear side of my layout so super-detailing is not a huge issue.
The fencing around the refinery area is the old Marx "cowboy" fencing that interlocks at the corners. The Marx two lamp searchlight tower throws a soft lighting effect on the scene; not the harsh lighting you would get if you used the larger Marx or Lionel light towers. I got the soft lighting idea from a refinery area I noticed while driving once on the NJ Turnpike in the evening.
In the photo below, you'll notice the three oil tanks. Aren't they classics? I made those tanks 39 years ago using common vegetable cans from my parents' kitchen, masking tape and grey spray paint. (When I started building my layout, I pulled out the first Colber oil well and those tanks from a box where they had lain for more than 25 years and thought: "They're going on the layout!"
I built the "dike" around the tanks from some balsa wood that simulated 6" X 6" timbers and "painted" them using a brown/black furniture finish touch-up pen from a hardware store.
I don't have any "oil company" decals on the tank, so you never know whose tank cars will be on the stub track. Sunoco and Cities Service tank cars have been spotted there in the past...