Definition - What does Porous mean?
Porous is a term that is used to describe a rock that has void spaces or small holes between rock grains that are not compacted together. The void spaces may contain fluids or air and they may be interconnected or isolated. Porosity represents the percentage of the void spaces in the rock in which oil and gas can be accumulated. Effective porosity is determined by the interconnected pore volume in a rock and it affects the flow of fluids in a reservoir.
Petropedia explains Porous
Rocks contain void spaces between the rock grains. The grains are solid or rock material and thus a rock formation is said to be porous if there are void spaces or pore volume between the rock grains. Hydrocarbons are contained within the pore volume of a rock and can flow through the interconnected pore volumes in a hydrocarbon reservoir. The porosity of a rock is the ratio of the volume of the void spaces divided by the total volume of the rock. For most rocks, porosity varies from less than 1% to 40%. If a rock has 8% porosity, it is considered to be an economic deal for the operators and E&P organizations and can be developed into a decent hydrocarbon reservoir.