Several important factors have changed. Instead, there has been a paradigm shift in exploration philosophy. Large seismically mapped prospects are not the only exploration targets considered. In the past, the exploration philosophy focused on the many large well-defined prospects because risk analyses favored them over smaller prospects and stratigraphic traps which were not as well defined on available seismic.
Risk assessment is an important facet of tract evaluation and determining economic potential .
Currently, drilling and seismic have discovered and proven that the comparatively smaller North Slope fields like Kuparuk River, Endicott or the recently announced Alpine Unit are royalty-producing realities. Similar geologic prospects probably extend through the NPR-A. Consequently, these kinds of exploration targets are now being sought and evaluated. Our resource evaluations suggest these exploration targets have recoverable reserves of approximately 100 million to 1 billion barrels each. They are considered economically viable in NPR-A for two major reasons. The primary reason is because current development facilities have expanded in stepwise fashion outward from the Prudhoe Bay field to the Kuparuk River field and now to the Alpine field.