The US Geological Survey (USGS) has released its first estimate of the total amount of onshore oil and gas on Alaska’s North Slope. The estimate claims a “potential of undiscovered, technically recoverable” resources totaling up to 2 billion barrels of oil and 80 trillion cubic feet of natural gas.
Keep in mind that the probability range for that estimate is 5% to 95% that either the oil or gas resource is that large. About a month ago, the USGS revised its initial estimate of the total amount of natural gas in the Marcellus shale gas play from 410 trillion cubic feet to 141 trillion cubic feet — a drop of 66%.
As more drilling is accomplished, the actual size of the proved, recoverable reserves becomes better known. Here’s how the USGS puts it:
There is a large range of uncertainty associated with these assessment numbers, because of the uncertainty associated with estimation of undiscovered, continuous resources in source rocks from which no attempt has been made to produce oil or gas.
Clearly the USGS numbers are encouraging. But that’s all they’ll be for at least another ten years.