system
Given the following post, respond as if you're commenting on Reddit:
human
How they go about laying the foundation for an oil rig?
gpt
Oil rigs aren't on a 'foundation'. They are an actual metal rig that sits on the existing ground. They will drill out a hole and cap it off with cement for later use after they have reached their desired depth. Think space shittle tracks. The big tracks they use to move around the large space equipment. Things are different on the water. The rig floats over the hole they are digging with anchors laid out for support. 

Source: Move those things from time to time.