The tremendous expanding demand for petroleum and its products that continues to develop means that we must take a hard look at our future sources of petroleum supply. In spite of the fact that most exploration has been and is directed toward the search for petroleum in local structural traps, many of the largest oil and gas pools in the Western Hemisphere are trapped by non-structural phenomena. Structural traps are so obvious that they are the first to be tested, but we are now facing a situation in which the supply of structural traps in the United States seems to be limited; untested anticlines are becoming more difficult to find. Does this indicate an impending shortage of petroleum? The answer would seem to be no--but this means that the search will have to be for m re obscure and subtle trapping situations. The search will continue for the purely structural trap, out there will be added stratigraphic variations and fluid-flow phenomena, all operating either together or independently.

We have "stumbled" into many great non-structural oil and gas pools while looking for purely structural traps, but the time seems to have arrived when we must start looking directly for combination traps of all kinds involving different proportions of structure, stratigraphic change, and fluid-flow phenomena. Such traps may contain very large petroleum pools, as past experience has shown.

There are in the Rocky Mountain region many such untested potential combinations of large structures, stratigraphic changes, and favorable fluid-flow conditions to justify the belief that this region has a continued great future as a petroleum-producing region of importance to our national needs. The fact that the Rocky Mountain Section of the Association is dedicating a full meeting to the obscure and subtle trap is a sure indication of a change in our thinking. Once we start actively to look for traps that combine structure, stratigraphic change, and fluid phenomena instead of to look only for local structure, there is no reason why discoveries in the United States should not continue to meet the demand. The Rocky Mountain region has as bright a future for petroleum discovery as any other.