Exploration geologists and engineers use a variety of techniques to locate subsurface oil and natural gas. Data from nearby wells, regional geology, computer models, satellite imagery, and mapped surface oil seeps can help predict where a productive oil well might be located.

Seismic surveying is one of the most effective methods of finding oil and gas because it enables geologists to map underground formations and structures. A noise source—either a vibrating/thumping truck or an explosive discharge—directs sound waves through the subsurface. The waves reflect off the different rock layers and structures. Geophones record the time it takes for the waves to return to the surface. The raw seismic data are then processed and interpreted to determine the possibility of oil and/or gas. Three-dimensional seismic surveys allow geologists to make even more accurate interpretations and predictions of oil and gas deposits.

Drilling exploration wells confirms whether oil and/or gas exists in a suspected area or formation. While some exploration wells lead to the successful discovery of hydrocarbons, others turn out to be “dry holes.” On occasion, exploration wells help locate hydrocarbons in rock layers other than the original target formation.