The last projection I saw was they would switch to natural gas in 20 years and run that for 40+ years. That is IF no new exploration areas are opened, then the need a second pipeline to carry gas.
They are only drilling a 25 mile by 50 to 65 mile section of what is a +/-900 mile by 200 mile field. The Dems have so far blocked further opening of new areas.
The field started at 1.4 million barrels per day...
Maintenance is another factor. The facilities have reached the design life and are being refurbished during temporary down times. That negatively effects the production rates when they are not running because of repairs.
I've worked in Alaska designing production facilities on the Alaskan North Slope.
What 900 mile long field are you thinking of?