High EROI Values for Shale Gas
Mike Aucott shows us that the EROI value of shale gas could be much higher than is assumed by many, namely in the range of 70-100+. He arrives at his conclusions by making use of CO2 emission data related to drilling for shale gas, which he uses as a measure for the amount of energy used to extract the shale gas. Energy necessary to produce the drilling hardware and related equipment is included as well. Aucott estimates the total energy cost for a shale gas well at 30 billion Btu. Another method of calculating the energy cost is to start from the financial cost of a well and translate that cost into energy cost, using the average amount of energy associated with a dollar of gross domestic product (GDP). Result: 35 billion Btu. A typical Marcellus well yields an estimated 2.9 billion cubic feet and thus Aucott arrives at EROI values of 70 or higher, which is extremely good. Aucott concludes that shale gas is not a bubble, but here to stay. And that gas is bound to overtake petroleum in the years to come. But at the same time he doubts that shale gas reserves are big enough to replace oil in the role it plays today. At the same time he points at dangers: gas leaks and its effect on global warming, surface water/drinking water well pollution by flowback fluids and/or gas itself, explosion hazards.