Associated petroleum gas (APG), or associated gas, is a form of natural gas which is found with deposits of petroleum, either dissolved in the oil or as a free "gas cap" above the oil in the reservoir. The gas can be utilized in a number of ways after processing: sold and included in the natural-gas distribution networks, used for on-site electricity generation with engines or turbines, reinjected for secondary recovery and used in enhanced oil recovery, converted from gas to liquids producing synthetic fuels, or used as feedstock for the petrochemical industry.