We have had this issue discussed elsewhere. There is just not enough oil in ANWR to see any significant increase in supply. It is not an "easy" answer - oil prices have fallen so greatly in the last 6 months that OPEC has cut production and this changes the equation drastically. The big problem now is the gutting of what is left of the US economy and the mortgaging of the future to protect the interests of a few.
From Wikipedia:
In 1998, the USGS estimated that between 5.7 and 16.0 billion barrels (2.54×109 m3) of technically recoverable crude oil and natural gas liquids are in the coastal plain area of ANWR, with a mean estimate of 10.4 billion barrels (1.65×109 m3), of which 7.7 billion barrels (1.22×109 m3) lie within the Federal portion of the ANWR 1002 Area.[16] In comparison, the estimated volume of undiscovered, technically recoverable oil in the rest of the United States is about 120 billion barrels (1.9×1010 m3). [23] The ANWR and undiscovered estimates are categorized as prospective resources and therefore, not proved.
The total production from ANWR would be between 0.4 and 1.2 percent of total world oil consumption in 2030.