If you had 10 billion barrels of oil, at $80, and you manage to extract 3/4 of it over 30-40 years. Maybe you get a net $5-$10 billion per year economic benefit from that if you're lucky as the US. The US military budget is $800 billion every single year. The US isn't doing this for oil, it's about positioning vs other world powers.
Military projection, global strategic positioning, always trumps something like oil (especially when the US has plenty of that resource).
The US went into Iraq because of Russia, not because of oil. That was a Pentagon program to try to strip Russian influence out of the Middle East, stated directly by four star general Wesley Clark.
The US went into Syria because of Russia, not because of oil. The US is still in Syria because of Russia, not oil.
Most (not all) of what the US does in the Middle East is a power conflict with Russia.
Most of what the US now does in Asia is a power conflict with China.
Oil is a little toy chip on the table compared to the real stakes.