Hydraulic fracturing uses water – a lot of water; although the amount of water needed to frack a well is significantly less than the amount needed for some other uses, e.g. production and treatment of coal. Driven in part by the criticism over the amount of water used in hydraulic fracturing, some energy companies are becoming more receptive to alternatives. One leading alternative that is gaining traction with some companies is fracking with liquefied petroleum gas (LPG). This technology was developed in Calgary, Alberta by Gasfrac Energy Services a few years ago, and allows fracking to be done with propane, butane or pentane – or mixtures of those gases – as a substitute for water. These gases are already found in natural gas wells. About 2,100 fractured wells using this technique are in the ground, with test wells under way in Texas. The most obvious advantage of LPG or gas fracking is that water is not needed, little or no flaring when fracturing, 100 % of the fluid used in fracturing is recoverable for sale later and no need for treating and transporting water afterwards. 

In LPG technology, a gel containing sand or man-made materials is pumped deep into the shale formations, creating enough pressure to hold cracks open far below the surface and allowing gas to escape. The material used to frack a well using LPG technology has low viscosity and low surface tension, compared with the surface tension of water. Total yields can be as much as 30 % higher than if the well were hydraulically fractured. After the pressure and heat turn the gel into a vapor, it moves up to the surface, where it can be collected and sold down the line. Gas fracking allows other materials, such as salts, drilling chemicals or radioactivity, to remain in the ground.

Reproduction of the Article “Fracking Goes Waterless: Gas Fracking Could Silence Critics” by Gene Lockard on Rigzone.