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Transcript for Wrestling with Uncertainty, segment 12 of 16
Up until now conventional resources have provided most of our oil and gas so past national assessments have focused primarily on potential additions to reserves from undiscovered conventional petroleum accumulations. More recently, we've expanded coverage of other resources, particularly unconventional accumulations in field growth. Conventional accumulations have distinct boundaries marked by a sharp contact between oil or gas and water, but unconventional resources are disbursed over wide areas and have poorly defined edges. They contain vast amounts of oil and gas, but much of it remains outside our reach.
Beneath us here in southwest Wyoming lie layers of rock that extend for hundreds of square miles and contain natural gas throughout their extent. Some geologists estimate as much as five thousand trillion cubic feet, enough to last us more than two hundred years at the rate we use natural gas today, but the rock is a tight sandstone with properties so variable that predicting the location of economic concentrations of gas is exceptionally difficult, and when a well is completed, it may not produce enough gas to become profitable. We could have a well, for instance, right here, and we might be lucky enough to drill into a sweet spot and strike it rich, but a well just over there might not find enough gas to grill a steak.
These unconventional accumulations include tight gas sands in Wyoming, huge oil accumulations in Montana and the Dakotas, and coal beds that produce natural gas in Colorado, New Mexico, and Alabama. With present technology many of these deposits are simply too expensive to develop, but they represent a vast source of energy that might well be released by future research and innovation. Nevertheless, we base the assessment only on what's within our grasp today. For these unconventional accumulations we assume that the undeveloped parts of the resource will show similar characteristics to those that have already been drilled. Using statistical procedures we can project what we know of existing production into the untested portions of the accumulation and generate an estimate of what remains to be discovered.