Abstract
Use of hydraulic fracturing in the completion of oil and gas wells in tight geologic formations has revolutionized the petroleum industry by increasing production and the quantity of available reserves. The practice has been controversial because of real and perceived environmental impacts, particularly groundwater contamination. A detailed scientific analysis of the potential environmental impacts of hydraulic fracturing of the Sunniland Formation in southern Florida was performed to assess the potential for environmental harm. The Sunniland Formation is located more than 3000 m below land surface and is confined by a series of low-permeability geologic units, which protect the shallower fresh groundwater resources from contamination. Freshwater aquifers occur primarily between land surface and a depth of 100 meters. Multiple well casings separated by cement grout also add a high degree of aquifer protection as required by Florida laws and rules for both oil and Class I and II injection wells. Collection, containment, and treatment of flowback fluids and produced water (saltwater containing residual hydrocarbons) are required by law and are monitored by the Florida Department of Environmental Protection. Produced water has been disposed of successfully in Class II injection wells for the past 60 years without recorded groundwater contamination. Based on a rigorous scientific assessment, the risk of groundwater contaminant and other environmental impacts is minimal. In southern Florida, there is no scientific basis for banning the hydraulic fracturing process on geologic units that contain oil and gas.
