An engine oil pump should last from 60,000 to 80,000 miles and sometimes as long as 100,000 to 300,000 miles depending on how well you take care of the engine.
If you change the engine oil often as in every 3,000 to 5,000 miles and change the oil filter as well during those oil changes then the oil pump should last the life the vehicle or the life of the vehicles engine.
I have a truck with 300,000 miles on it with the original oil pump and I've always changed the oil and oil filter every 3,000 miles.
Some people do not change their engine oil often enough and then it leads to oil pump failure and engine failure as well.
I'm gonna replace my engines oil pump soon though when I take the oil pan off and replace the bearings just because they have so many miles on them.
But the bearings and oil pump would probably last even longer.
When you change an oil pump on an engine you must prime the engine and oil pump to provide lubrication upon startup.
The oil pump is the heart of the engine and if not installed properly or primed properly then the engine will not get any oil pressure and then seize up.