Slickwater

From Wikimarcellus

Slickwater or slick water fracturing is a method or system of hydro-fracturing which reportedly involves injecting friction reducers, biocides, surfactants and scale inhibitors. For example methanol and naphthalene can be used for biocides. Hydrochloric acid and ethylene glycol may be utilized as scale inhibitors. Butanol and ethylene glycol monobutyl ether (2-BE) are used in surfactants. It typically uses more water than earlier fracturing methods--between one and five million gallons per fracing operation.

Other chemical compounds sometimes used include benzene, chromium and a host of others. Many of these are known to be toxic and have raised widespread concerns about potential water contamination. This is especially true when the wells recieving slickwater hydro-fracturing are located near aquifers that are being tapped into for local drinking water.

It is a water-based fluid and proppant combination that has low-viscosity. Slickwater fracturing was first used in the Barnett Shale. Mitchell Energy introduced the very first slickwater frac that utilized 800,000 gal. of water and 200,000 lbs. of sand as a proppant. It is typically used in highly-pressurized, deeper shales, while fracturing fluids using nitrogen foam are more common for more shallow shales and those that have lower reservoir pressure.