A controversial method
Despite its benefits, hydraulic fracturing has opponents. Primarily, many people are worried about the potential harm the method could do to the environment.
Fracking for oil and gas both involve injecting pressurized fluids into the ground. In both cases, the fractures that are created allow energy companies to more easily capture the natural resources from the ground as they flow up. They can be accessed through either shale formations or oil and gas fields. In general, the two processes are very similar. Some wells will only contain gas while others solely hold oil, but there are many reserves that contain both fossil fuels. The main difference between the two methods is that most shale oil formations only need to be fracked once, whereas natural gas formations generally require multiple fracking processes to access the reserves, according to FrackingOil.com.