Pumping CO2 into Frack To Prevent Contamination

Sometimes two problems can cancel each other out. Carbon dioxide emissions from power plants could be put to good use, preventing fracking chemicals from contaminating drinking water supplies

Although fracking has unlocked new fuel sources and slashed energy prices, there is a risk that toxic compounds in the fracking fluid can get into shallow aquifers via fractures in the bedrock.

Andres Clarens at the University of Virginia in Charlottesville and his team say pumping CO2 into the wells could prevent this. At the high temperatures and pressures found at depth, it reacts with silicate minerals in rocks to form a carbonate deposit.

In the lab, the team has mimicked conditions in the Marcellus shale, a vast hive of fracking activity beneath New York state and Pennsylvania. They found that half of the CO2 injected in their experimental simulation was converted into solid carbonates within a day.

The same would have happened to the rest before it could leak out to the surface, says Clarens, who presented the work this week at the Goldschmidt conference in Prague, the Czech Republic.

The technology for injecting CO2 into rocks already exists, says Clarens, and models suggest that shale has an enormous capacity for storing it.

The idea is fascinating, says Richard Davies, a petroleum geologist at Newcastle University in the UK – but unnecessary. “Fractures rarely extend past a few hundred metres above the shale reservoir,” he says.

Source: New Scientist

Read More Related Content On This Topic - Click Here

Media

Taxonomy

• Pollution
• Fracking
• Drinking Water Managment

1 Comment

1. Certainly, the technology exists and there's a lot of on-going research on CO2 sequestration. Yet, in my opinion, injecting CO2 just to settle the fracking toxic compounds and to prevent them to reach shallow aquifers through caprock is fissures is a bit risky. What if the well casing has a breach at shallow depths and you are injecting CO2? That would go directly to the shallow aquifer... This, although sounding a bit like science fiction may happen. It actually happened, but while injecting just water in Landau (in Germany, a deep geothermal project). The ground level raised centimeters due to the overpressure at the shallow aquifer. Consequence: cracks. Many. Therefore, while the idea is good (and CO2 certainly precipitates or stays in supercritical state), must be "handled with care".