I worked in the production end of things in Prudhoe Bay for a very long time... There were some cement issues there and problems caused by fracing. But in the grander scheme of things I believe the whole concept was flawed from inception because the basis for doing it was not rational. It was used in PB to increase production immediately in a formation with tremendous porosity and permeability. What it did was generate production problems: dealing with sand flowing back, gas or water flow encroachment from increased production (water and gas both move through the formation better than crude due to viscosity) increasing water and/or gas enough to wash through the oil creating "fingers" of production and ruining wells in the process, and fracing that exceeded the target zones.

It was seldom long-lasting and usually led to wells being shut-in shortly after fracing. The numbers of incidents with frac sand jetting holes in production pipe was significant... the amount of sand (actually eopxy coated balls of sand there) used was prodigious... And the basic flaw was based on bean-counters and their belief that money not made within 7 years is not made... It slowed the decline in production curve significantly, but only for a while.

FWIW Prudhoe Bay and the Trans-Alaska Pipeline are in a serious jam right now. The production has fallen to under 300,000 barrels per day of oil (from 1.8 million) and TAPS is actually transporting oil at a rate significantly below the design parameters. That means the oil is much cooler when it gets to Valdez, but also means the temperature related problems from waxes in the oil are getting worse all the time. A shut-down right now could cause them all sorts of problems. If production drops just a tiny bit more the line will likely have to be shut down. Of course every reasonable projection shows a decline in production...