To build your pump:
1. Make a couple of towers of tanks on dry land. The amount and height of these tanks will depend on the size of your supply of oil. (Lava and water can also be extracted.)
2. connect a series of pipes heading toward the top of your supply.
3. Place a pump at the end of the pipes, making sure the pump isn't IN the supply. A black pipe will begin to descend into the supply.
4. Directly connect a stirling engine to this pump, also making sure it isn't in the supply.
5. Lastly, place a lever right next to the engine and turn it on.
You can make your connections as small, big, simple, or complicated as you like. It's up to your imagination! :D