The liquid and gaseous hydrocarbons could travel rather large distance in the porous sedimentary rock. Under the influence of the geologic structures and gravity, some of the hydrocarbon material accumulated in the geologic traps. Porous Figure 2.1 A typical geologic formation in which oil and natural gas are found The gas if found above the oil, and the oil above water, all interspersed in a porous formationFigure 2.1 A typical geologic formation in which oil and natural gas are found. The gas if found above the oil, and the oil above water, all interspersed in a porous formation. • The liquid and gaseous hydrocarbons could travel rather large distance in the porous sedimentary rock. Under the influence of the geologic structures and gravity, some of the hydrocarbon material accumulated in the geologic traps