Air Products supplies nitrogen for fracturing fluids that can provide performance and cost advantages over water-based fluids in certain formations. Although water-based fracturing fluids are widely used for hydraulic fracturing because they are inexpensive and offer good proppant transport into the fracture, they do have drawbacks. Water-based fluids are unsuitable for water- sensitive formations because they can cause water saturation around the fracture and clay swelling, which may significantly hinder the mass transport of hydrocarbons from the fracture to the well bore. Nitrogen fracking fluids are an excellent alternative to water-based fluids in water-sensitive formations, depleted reservoirs, and shallow formations.
Four main types of nitrogen fracturing fluids are used commercially: pure gas, foam, energized, and ultra high quality (mists). Foam fracturing fluids typically consist of a water-based system and a gas phase of nitrogen in the range of 53% to 95% by volume. Below 53% nitrogen, the fracturing fluid is considered energized. Above 95 % nitrogen by volume, the fracturing fluid is considered a mist. A fifth type, cryogenic liquid nitrogen fracking fluid, has also been used, but is rarely employed for commercial operations due to special material and equipment requirements.
Read our Special Application Report on "Nitrogen Fracs Can Decrease Water Use in Amenable Geologies," which was originally published in CryoGas International.
Economics and applicability of nitrogen for fracking
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Enhanced Unconventional Oil and Gas Production with Nitrogen and Carbon Dioxide Fracturing
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