Conventional vs. Unconventional Oil supplies

Contrary to what would seem logical, estimates of oil and natural gas reserves may increase as they are depleted, as the new USGS assessment of recoverable oil reserves in the greater Bakken Basin shows. How does this square with peak oil theory?
May 9, 2013   MIT Technology Review
Conventional oil supplies peaked at about 70 million barrels a day in 2006 according to the IEA, and will hold steady until 2035. However demand, primarily from China, will require an increase of 20% in oil to be filled by 'unconventional' supplies.
Nov 16, 2010   The New York Times - Environment - Green blog