There is a theory that oil reserves go a lot deeper than thought, with some very deep, large pools that constantly leak oil upwards through cracks in the earth. So a pool that is pumped dry, may constantly be refilled from lower reserves that are much larger than the upper pools. What this means, is that the reserves may be much larger than expected.

Technology is also expanding dramatically, so new pools are being both discovered and becoming reachable.


All this, however, does not account for areas where known oil is not being pumped. In addition to the areas in Chehalis that were mentioned, my in-laws have a large parcel of land in Tennessee that has oil on it. They know its there, but the price to extract it is too high at this time. The family has been holding on to for almost 100 years, hoping some day to cash in. I wish they have just bought some farm land around Seattle a hundred years ago instead, and held on to it. We would all be rich.