The theory on trapping is discussed in this lecture. A trap typically is the final place where oil an gas end up. The most important job for exploration geologists therefore is to find the traps. These traps can be either structural traps, caused by tectonic forces, or stratigraphic traps, which mainly has to do with the way the sediments have been deposited. The most typical traps, where 80-90% of the oil is trapped, are anticlines which are structural traps with arched upper surfaces.

To illustrate the theory further, the lecture continues with the discussion of some case studies on structural traps, stratigraphical traps, combination traps and dynamic traps.