Ladies and Gentlemen: I plan to discuss today the most likely places where oil will be discovered in the future in the United States as well as some of the technical problems of drilling for and producing this oil.
PAST SEARCH FOR PETROLEUM
If we review the history of the search for petroleum, we find that early explorers soon recognized that oil and gas often occurred in anticlinal structures. Differential buoyancy caused the lighter gas to accumulate in the attic of the structure above the oil which in turn was on the top of the ever-present water found in all formations at depth. Once this relationship was established practically the whole exploration effort was devoted to the search for anticlines, first by surface geology using plane table mapping and other techniques, followed by the extremely successful seismic method initiated in the late 20's. Seismic mapping proved so effective in locating subsurface anticlines that discoveries accelerated at an unprecedented rate which, combined with the great depression of the 1930ts, caused the price of oil to drop to as low as 10 cents per barrel. In the process of searching for anticlines, or in some cases purely by random drilling some large non-anticlinal fields or stratigraphic traps were found. Many in the industry realized that large accumulations of stratigraphic trap oil likely existed, but at that time it was not commercially feasible to search for it by a combination of subsurface geology and drilling numerous wells to define the possible trap, except in the case of very shallow prospects.
SLIDE 1: GIANT FIELDS CONTAIN MOST OF WORLD'S OIL
This slide shows that over 85% of all of the oil found in the past, about 1 trillion barrels, was found in fewer than 300 giant oil fields which comprise less than 1% of the more than 30,000 oil fields in the world.
SLIDE 2: MESOZOIC-TERTIARY SEDIMENTS HOLD MOST OF WORLD'S OIL
Another very significant fact is that worldwide over 85% of all of the oil found in the past has been found in sediments of mesozoic and lower Cenozoic or Tertiary age. Older sediments generated, but lost in countless, subsequent geologic revolutions, vast amounts of oil and gas. Younger sediments of the late Cenozoic contain the essential organic material to form petroleum, but these sediments have not reached maturity for petroleum generation.
Aside from the above two points, a third significant factor in oil exploration is that the first company to explore an area has generally found the giant fields.
Thus from these significant bits of information, one could conclude that the search for the giant fields of the future should be focused on basins containing thick accumulations of marine Mesozoic and Tertiary sediments which have not been thoroughly explored. Such areas in the U.S. include most of our offshore areas, the Rocky Mountain overthrust belt, and the deep Tuscaloosa-Woodbine trend of the Gulf Coast where a great deal of exploratory activity is concentrated.