The U.S. Geological Survey has, in collaboration with the U.S. Fish and Wildlife Service, issued a report with the title, “Hydraulic Fracturing Fluids Likely Harmed Threatened Kentucky Fish Species” (read the report). They assert:
Hydraulic fracturing fluids are believed to be the cause of the widespread death or distress of aquatic species in Kentucky’s Acorn Fork, after spilling from nearby natural gas well sites. These findings are the result of a joint study by the U.S. Geological Survey and the U.S. Fish and Wildlife Service. The Acorn Fork, a small Appalachian creek, is habitat for the federally threatened Blackside dace, a small colorful minnow. The Acorn Fork is designated by Kentucky as an Outstanding State Resource Waters.
“Our study is a precautionary tale of how entire populations could be put at risk even with small-scale fluid spills,” said USGS scientist Diana Papoulias, the study’s lead author. “This is especially the case if the species is threatened or is only found in limited areas, like the Blackside dace is in the Cumberland.”
A component in the success of fracking is the fluids that they pump down the borehole under high pressure – hydraulic fracturing fluids. A surprising thing is that the companies doing this do not need to report the chemical components of the fluids – these are company secrets. It is these fluids that now threaten the rare fish. Of course, the companies assert that the fluids are not damaging to the natural environment if they are used in the correct manner. ExxonMobil ExxonMobil gives us the following information on “hydraulic fracturing fluids”:
Hydraulic fracturing fluid is typically comprised of approximately 98 to 99.5 percent water and sand and 0.5 to 2 percent chemical additives. Most of the chemical constituents that make up fracturing fluid additives can be found in common household items or in the food and drinks we consume. The chemicals in hydraulic fracturing fluid are used to reduce friction and protect the rock formation, thereby making the hydraulic fracturing process safer and more efficient.
If we visit Wikipedia we find the following information on hydraulic fracturing fluids:
Typical fluid types are:
Conventional linear gels. These gels are cellulose derivatives (carboxymethyl cellulose, hydroxyethyl cellulose, carboxymethyl hydroxyethyl cellulose, hydroxypropyl cellulose, methyl hydroxyl ethyl cellulose), guar or its derivatives (hydroxypropyl guar, carboxymethyl hydroxypropyl guar) based, with other chemicals providing the necessary chemistry for the desired results.
Borate-crosslinked fluids. These are guar-based fluids cross-linked with boron ions (from aqueous borax/boric acid solution). These gels have higher viscosity at pH 9 onwards and are used to carry proppants. After the fracturing job the pH is reduced to 3–4 so that the cross-links are broken and the gel is less viscous and can be pumped out.
Organometallic-crosslinked fluids zirconium, chromium, antimony, titanium salts are known to crosslink the guar based gels. The crosslinking mechanism is not reversible. So once the proppant is pumped down along with the cross-linked gel, the fracturing part is done. The gels are broken down with appropriate breakers.
Aluminium phosphate-ester oil gels. Aluminium phosphate and ester oils are slurried to form cross-linked gel. These are one of the first known gelling systems.
When ExxonMobil says “most of the chemical constituents that make up fracturing fluid additives can be found in common household items or in the food and drinks we consume” one becomes a little worried about the food one is eating and the chemicals one is using at home. I hope the vegetable soup is OK! The question is whether we will be reassured when we read about Halliburtons new hydraulic fracturing fluids:.
CleanStim fracturing service uses a new fracturing fluid formulation made with ingredients sourced from the food industry. Acquiring the ingredients from the food industry provides an extra margin of safety to people, animals and the environment in the unlikely occurrence of an incident at the wellsite.
More and more people who live in areas where fracking is occurring are becoming worried. It takes only 5 years to empty most of the accessible oil from a fracking well and the question is if this short term economic gain will destroy the local environment in the longer term. I believe that the people living in areas where fracking could occur will demand more information and we will certainly see bans on fracking.