Early Game Oil Rig

Well, I got my oil rig with just three plots of land. I could have done it with two, but the oil rig shows up at level 18. I had enough gems to buy land and building stuff is the quickest way to get experience so you go up in level.

I did this once before with just two plots of land, so it absolutely can be done. I actually started over many times before getting this result and took a zillion screenshots, which I might publish elsewhere. These are just the end result.