Shale Gas 101 – Extraction
Shale gas is extracted using an amalgamation of different methods and technologies, the most important being directional drilling and hydraulic fracturing. Shale gas is natural gas trapped within shale formations. Shale formations have low permeability which historically had made extraction a difficult process and not economically viable. Today advances in directional drilling and hydraulic fracturing have made shale gas a viable source of energy. The extraction process starts with drilling a vertical well down to the shale layer, where then a horizontal well is drilled throughout the shale layer using a solution known as ‘mud’ to cool and lubricate the drill. Once drilling is completed a casing pipe is put down the vertical & horizontal well, then cement is pumped throughout the well to create a cement wall between the well and the outer layer. A cement plug is inserted into the well to create separate sections. A pipe gun is fed through the horizontal well where explosives are fired creating a fracture in the shale formations. A mixture of water and sand is then fed through the fracture, which in larges the fracture and enables the gas deposits to be collected. After this process the water, sand and gas deposits are extracted.