What Is Fracking?

Fracking (or hydraulic fracturing) is the extraction of natural gas from within thin layers of shale in the earth’s crust. Here’s how it works:

•        Fracking fluid, made up of water, sand and over 600 chemicals, is injected at high pressures into a well around 3000m below the surface – depth is location dependent.
•        The pressurised mixture causes natural fissures and layers in the rock to crack.
•        Sand particles then hold these fissures open allowing natural gas to travel up to the surface.
•        Once extracted it is separated into dry gas for power generation/industrial uses and natural gas liquids for chemical feedstocks.
•       The fracking fluid is recovered and taken for reprocessing to be used again.

Cross section of a typical fracking sight. Source

Although fracking has only dominated headlines in the past couple of year’s techniques have been developing since the early 1900s. Fracking has grown in popularity recently due to the depletion of global oil and coal reserves. The graph below shows how we have moved from one resource to another as soon as it is depleted. Could natural gas be our new main energy source to replace oil?

The four eras of energy. Source

I found a very clear timeline of the history of fracking in the USA on Quora which gives details of how the process has evolved since first being established in Pennsylvania over 80 years ago. However, in the UK fracking is a lot newer and its potential as a new energy source is still be questioned. Fossil fuels such as oil, natural gas and coal are the largest sources of energy in the EU and are predicted to dominate the European energy mix until at least 2030 (EERA, 2013).