By: Robert Miles, July 2013
Drilling rig on the Pinedale Anticline (Linda Baker)
Natural gas produced from shale formations, commonly referred to as “shale gas”, has become increasingly important in the energy supply market for the U.S. and worldwide. Obtaining natural gas from shale reserves was not considered economically feasible until recently because of low permeability of the shale rock formations. New developments in hydraulic fracturing technology have led to a boom in domestic shale gas production since massive scale utilization in 2003. The United States has experienced economic benefits via revenue and job creation in predominantly rural areas while simultaneously increasing the energy security of the U.S. by decreasing dependence on foreign oil supplies. However, the resounding question remains: at what cost? In order to realize the implications of this question we first need to understand some basics about the hydraulic fracturing process and the uncertainties that continue to surround the shale gas industry. In this report I will primarily focus on the environmental impacts of hydraulic fracturing and well development, but it is important to realize that direct impacts on the environment can and will extend to affect human health.
Hydraulic fracturing, or “fracking,” is a stimulation process used to extract natural gas, and in some cases oil, from deep shale reserves 5,000-8,000 feet below the ground surface. This process allows energy companies to access previously unavailable energy sources in states that have deep oil and gas reserves. The fracking process involves pumping a mixture of water, chemicals and sand at high pressure into a well, which fractures the surrounding rock formation and props open passages that allow natural gas to freely flow from rock fractures to the production well. Once the well is developed, the carrying fluid can then flow back to the ground surface along with the gas.
Geothermal energy is the Earth’s own internal heat. It’s a huge potential resource, but so far it’s seen only very limited use. Traditional geothermal power can only work where there are naturally existing hydrothermal systems that bring the heat of the interior to the surface. A new technique called enhanced (or engineered) geothermal systems (EGS) may make geothermal power much more widely available. If it can be scaled up commercially, EGS will enable us to create hydrothermal systems anywhere there’s hot rock not too deeply buried — which includes a large swath of Colorado. This is potentially significant in the context of creating a zero-carbon electrical system because like hydroelectricity, and unlike wind and solar, geothermal power can be dispatchable: you can turn it on and off at will. This makes it a great complement to intermittent renewable power, as it can be used to fill in the gaps then the wind’s not blowing or the sun’s not shining. It remains to be seen whether it’s technically feasible, and if so at what price, and on what timeline, but it’s certainly worth investigating.
A recent study done by the US Geological Survey (USGS), published by Seismological Society of America, states that the recent increase in hydraulic fracturing may be directly correlated to the increased number of earthquakes.
According to the study led by US Geological Survey geophysicist William Ellsworth, the recent surge of earthquakes since 2001 near oil and gas extraction operations is “almost certainly man-made.” In 1991- 2001 oil and gas companies drilled 245,000 wells in the U.S. compared to 405,000 wells between 2001 and 2010 — a 65% increase.
Between the states of Alabama to Montana there were 134 earthquakes last year, which is a sixfold increase compared to the levels of earth quakes in the 20th century. The scientists believe that the increase in earthquakes is because of the increase of drilling sites along with the increase of fluid being injected into the ground.
For the USGS study visit here
For original article, please visit: The Environmental Working Group