The Geological Risks of Hydraulic Fracturing
There has been widespread debate regarding the environmental risks of hydraulic fracturing, especially concerns about ground water contamination. The shale oil and gas industry is built on the technology of hydraulic fracturing, and it has made vast amounts of oil and gas shale resources extractable at reasonable costs. In simpler terms, hydraulic fracturing is a process where millions of gallons of water are mixed with acids and other chemical additives, and then pumped into underground shale formations, where oil and gas are trapped within rocks and sands. The high pressure caused by pumping the liquids into the earth “fracks” earth formations containing oil and gas, which in turn releases the resources causing it to flows out of the well.

Environmental activists protest the dangers of leaving large amount of these liquids underground due to the possibility of it reaching and contaminating ground water. The US Environmental Protection Agency (EPA) has conducted a study with regards to these complains. It found some cases where hydraulic fracturing has caused some underwater contamination, yet the study stated that these incidents are very rare. The EPA found that the reason those incidents occurred was because extraction companies did not comply with safety procedures; accordingly, it was individual mistakes and not hydraulic fracturing at large to blame.

The study triggered a wave of criticism from activists and academic environmentalists. The study was labeled for not disclosing anything new about the practices of extraction companies. Robert Jackson, an environmental and energy professor at Stanford, said that the study covered everything that was previously published on the topic, but failed to produce any new information. He also said that the biggest disappointment was that the agency did not do collect data from shale wells; neither did it present any projections for the anticipated environmental impacts of using hydraulic fracturing in the future.

Underground water contamination is not the only threat to the shale industry. In recent years, central US states hosting the largest hydraulic fracturing activity started to witness unusual seismic activities. The annual average quakes above 3.0 for the period 1973-2008 were at 24 per year. But from 2009 and recently 2014, the average has risen up to 193 per year, reaching 688 quakes for 2014 alone.

The US Geological Survey (USGS) admits that pumping any fluids deep into earth causes earthquakes. Liquids pumped at high-pressure causes geological faults to move resulting in earthquakes. However, the agency is reluctant when it comes to linking the abnormal seismic activity of central states to hydraulic fracturing alone. The USGS named two other sources of liquids being pumped into earth: enhanced oil recovery, and injection wells. Injection wells are used for the disposal of wastewater (which can contain brine, acids and other chemicals) which comes from most oil and gas extraction processes, including hydraulic fracturing.

These wells are used to inject wastewater into deep earth layers as a way to protect ground water from being contaminated. The USGS claims that various oil and gas extraction methods produce such wastewater, not just hydraulic fracturing, and that most wastewater is disposed of in the same manner. Nevertheless, the agency did not provide a convincing justification for the observed outbreak of seismic activity that coincided with the introduction of hydraulic fracturing activity nearby in the central US states.

Oklahoma has been well known for its oil and gas industry and for WTI crude oil benchmark. And oil and gas industry is still the state’s main driver for its economy today. Oklahoma has had the biggest share of seismic that occurred in recent year. In 2014 Oklahoma surpassed California in the number of earthquakes by three times. Just before 2009, Oklahoma was not even on the earthquake radar and now is has become the capital of earthquakes after exceeding California.

These development forced local authorities to take immediate action against injection wells. State Governor said that there is a clear correlation between seismic activity and injection wells. One of the actions taken by local authorities was to reduce the amount of liquids injected in these wells. The State Corporation Commission issued a plan to reduce the volume of injection by 38%. Additionally, because wastewater is unavoidable during oil and gas extraction, rising production costs have put more pressure on extraction companies.

Despite the ongoing debate about the relationship between injection wells and recent seismic activity, there are several questions regarding the future of hydraulic fracturing and the shale industry as a whole that need to be addressed. Since many states are expected to take similar actions such as Oklahoma, can the shale industry withstand additional regulations? And what can other countries learn from the US experience in shale oil and gas?
August 2017
« Feb