Don't need the oil to do it, just ~5 hours or so at the end. Right now, due to the bot land, I expect it'd be trivially easy for a techer to rush to 10k A, stock, switch to TMBR, and get over $30m NW. If you can manage 250 A per hit, which doesn't seem entirely unreasonable, you're looking at only about 300 turns spent getting BPT, land, and buildings.

Edit:
Yeah, the rebuild is only in the area of $300m for a country that size. Assuming 1400 turns of teching at 3k TPT and an average price of $1500 and a NW cost of $172/NW you're looking at a ~$35m NW jump.