Many houses use both natural gas and oil. One appliance that can use either gas or oil is the furnace. Based on cost, natural gas costs significantly less than heating oil does to run the furnace. To extract natural gas compared to extracting oil, the cost is pretty much the same. However, there are other factors in that a certain type of gas can be cheaper and easier to extract since it is lighter in weight.
Also, gas extraction may be the same as oil extraction, but handling and storing the gas is more expensive than oil. Plus, both of these things are used for different reasons. So, both of these things would be needed. Therefore, we will have to continue extracting natural gas and oil.