Shale gas was considered uneconomic to produce for long time. But technological advancements including horizontal drilling and hydraulic fracturing are helping to unlock enormous quantities of natural gas from shale reservoirs. The real breakthrough has happened recently – the advent of long reach horizontal drilling (up to 2-3km), combined with multi-stage hydraulic fracturing. The essence of the process is to pump fracking fluid down the wellbore until the pressure is so high that the rock breaks, creating a fracture network (similar to those which appear when hitting a windshield with a rock).