I am writing this letter in response to the hydraulic fracturing scare recently in our county. This is a complex and emotional issue. I am a production geologist employed with a major oil company and deal with hydraulic fracturing on a daily basis, but have no interest in the wells in Boulder and Weld County. I do, however, live in Lyons and care deeply about the environment and the health and safety of its citizens. I agree with Sapan Rinpoche (see Letter to the Editor, March 22, 2012) that we need to educate ourselves about this important issue.
Educating ourselves should involve evaluating all sides of the issues, including understanding what ‘frac’ing’ is and is not. Hydraulic fracturing is just as the name implies – breaking rock that contains natural gas by high-pressure water. The process is simple, but elegant. Initially, a hole about 8 inches is drilled to below any rock layer (a formation) that contains groundwater, sometimes as deep as 4000 feet, but the depth is mandated by the regulatory agency – in Colorado it is the Colorado Oil and Gas Conservation Commission (COGCC). Second, this larger hole is cased with steel and cement is put between the casing and rock. This steel casing is designed to protect the ground water. Third, a smaller diameter hole is drilled deeper, through many shale formations that have low permeability (will not let a fluid flow through them), to a point above the rock containing the gas. The well bore is then curved so it eventually will hit the desired gas bearing formation horizontally. Often the horizontal portion of the well through the gas bearing formation is greater than 7000 feet – more than a mile long! The well bore is lined with additional smaller steel casing and cement is pumped between the rock and casing. The well bore casing is tested for integrity and an electrical evaluation of the cement is made (a cement bond log). The steel casing is then perforated or sometimes a special type of casing that slides to make holes is installed. Water is pumped down the well at high pressure and out the holes to break the rock. Where I work, the water only contains a very small percentage of sodium chloride (table salt) and sand grains. The sodium chloride keeps the clay particles from swelling and the sand keeps the fractures open, but it is the pressure that creates the fractures. The fractures created are rarely greater than a couple of hundred feet vertically, if we are lucky. These fractures are very important because they increase the surface area where the gas molecules are located and allow the molecules to flow to the well bore. Hydraulic fracturing has helped to unlock massive onshore reserves of tight and shale gas in the US - enough for 250 years at current production rates, according to the International Energy Agency (IEA).
As an industry, we are not perfect, but we strive to explore, develop, and produce resources safely and responsibly. The well bores are designed to protect the groundwater, the gas bearing formations are thousands of feet below the ground water, and the created fractures are not able to reach the groundwater table. We have completed over a million (yes, a million) hydraulic fracturing operations in the U.S. since the 1940’s, approximately 35,000 per year. US Senator James M. Inhofe at a Senate Environment and Public Works Committee hearing stated that these hydraulic fracturing operations have been conducted “… without one confirmed case of groundwater contamination from these fracked formations.”
Why is hydraulic fracturing important? Ask the workers at the manufacturing plants that have returned to the US because of low energy prices; the operators of cleaner, cheaper natural gas electricity generators; and you, the citizens of Lyons, who benefit from natural gas infrastructure to your homes. Yes, please educate yourselves about hydraulic fracturing.