I honestly think that by the time offshore drilling actually became helpful, we would already be well on our way to phasing out oil. If we dump the money into technology rather than more oil, there is actually a chance that we could kick the habit by 2020-2025.
How? Methanol. The use of methanol has tons of benefits. It is basically a delivery system for hydrogen that would not force us to revamp our fueling infrastructure and requires only minor changes to the way our cars are built. It is safer than gasoline, nearly as easy to transport and store, has higher thermal efficiency thatn diesel fuel, production is FAR less energy-intensive then ethanol production, very high octane rating/knock resistance yields performance benefits.
Minor drawbacks: slightly corrosive (solved by using different materials in the fueling system), lower energy density than gas (compensated for by greater engine efficiency and larger tanks, plus energy content can be boosted up to 20 percent by using a simple catalyst that mooches heat from the exhaust), and methanol can be slightly toxic (should be able to neutralize toxicity through new production practices)
I know that sounds way too easy, and it is. It's hard to give an overview without oversimplifying. However, this method WILL allow us to make the switch to renewable, non-food-based fuels much faster than switching to hydrogen or electric alternatives. Plus, we would save over a trillion dollars in infrastructure costs.