Petroleum geology has evolved over the last 150 years from the application of simplistic basic geological surface observations to the utilization of highly advanced concepts of subsurface geology. During the mid-1800s, petroleum discoveries were primarily the result of the successful follow-up of lucky “wildcat” hunches.

Between 1891-1910 the most significant contribution to petroleum exploration was the quick accurate mapping method of low-dip surface structure. During the 1920s, advances in micropaleontology and stratigraphy paved the way for the recognition in the 1930s of yet another form of hydrocarbon reservoir: the stratigraphic trap, of which the East Texas field is a prime example.

Since the 1950s exploration personnel of major oil companies began to realize that sedimentology was the key to success in exploration.

Beginning with this recognition in the late 1940s, the first large-scale sedimentological research projects materialized. The 1947 report of the Research Committee of the AAPG, under the leadership of Shepard W. Lowman, of Rensselaer Polytecnic Institute, stated that research in sedimentology is the most-urgent need in petroleum geology. Project 51 of the American Petroleum Institute led to a methodical and detailed study of modem depositional environments on a scale not previously attempted.

In the research laboratories of the major oil companies, eminent team leaders gave modem sedimentology a boost that led to rapid breakthroughs and advances in petroleum geology.

One of the later major breakthroughs resulted from the application of seismic techniques to the study of subsurface strata, including the interpretations of their depositional environments, their lateral continuity, and their distinctive vertical sequences, a field known as seismic stratigraphy.

AAPG Search and Discovery Article #90937©1998 AAPG Annual Convention and Exhibition, Salt Lake City, Utah