Shown in green is a layer which got displaced by the red and yellow faults. The pink layer exemplifies the 3D nature of geology as demonstrated by the top surface cutting through some topographically high spots. After a great deal of data processing, an accurate image of the subsurface can be obtained. An example is shown in Figure 2 . This subsurface image is carefully examined for potential accumulation points of hydrocarbons.
Indications are bright amplitudes or structural high spots.
Currently, however, there exists no surefire method to locate the accumulation points. To prove the presence of hydrocarbons, a well needs to be drilled. Finding hydrocarbons does not mean that they can be produced economically. First, the reservoir might not be porous enough to contain large amounts of fluid. Second, although there are enough pores, they are often only partially filled with hydrocarbons.