We're missing the point.
Saudi Arabia's oil production is controlled by a monopoly which seeks to maximize its own profits while maintaining marketshare (a very tricky game).
Oil production in Texas was controlled by no one at first (leading to rampant overproduction, evaporating profits, and the bankruptcy of plenty an oil company).
Then Texas production was controlled by the TRC whose sole purpose was to keep prices from falling too low. The TRC was not in the business of ensuring high oil profits as it was run by the state, not the state-owned oil company (because there wasn't one...)
The difference between the two organizations is the critical reason why oil production looks like a perfect bell curve in Texas and will NEVER look like a bell curve in Saudi Arabia.
. Pump as much as you can, as fast as you can. Look anywhere, drill everywhere, make as much money as humanly possible in the shortest amount of time possible. (Uber Capitalist model). Limiting factor? Geology.
. Pump only as much as you have to. Maximize long term profits and marketshare. All profits go to a single government-run organization. If you overproduce, you are punished. (State-Run Model). Limiting factor? Economics/Politics
The two oil producing regions are very different from each other.
There's a reason that the USGS doesn't try to come up with depletion models...the reason is that depletion models are guesswork when you're talking about a country whose oil production is controlled by a king running a monopoly, not a CEO in a highly competetive marketplace.
The Persian Gulf is full of oil and the Saudis aren't even bothering to look. They don't need to.