QUESTION: There has been some talk of fracking in Canada using CO2 (and perhaps other gases) in place of water–or maybe to reduce the amount of water needed–in their gas and oil drilling. Is this accurate; and if so, is this technology practical in Ohio, and will it really reduce the amount of water that is removed from our lakes and streams and the amount of waste water that needs to be put into injection wells?
ANSWER FROM DOUG: Hydraulic fracturing using gases has been used for fracturing shale for many years. In addition to carbon dioxide, nitrogen and propane have been and are continuing to be used. All of these work to some extent but do not appear to be as effective as the large water/sand jobs in the deeper shale formations. They are used primarily in areas where the shales are shallow and do not have the reservoir pressure to return the large volumes of water. Although they do save water, so additional problems are associated with them. Both nitrogen and carbon dioxide require the well to be flowed back until the amounts of each are very low. Gas utility companies will not allow gas to be produced into their line with more than a few percent of nitrogen or carbon dioxide. This allows quantities of the gases and methane to be produced into the atmosphere. Since the carbon dioxide and nitrogen are extracted from the air in the first place, there is no net increase in these gases. However, methane, which is a more troublesome greenhouse gas than carbon dioxide, is released until the gas can be produced. Propane does not have this problem since it can be blended with natural gas and immediately put into a pipeline. However, propane is very dangerous to pump, and therefore, very few companies are currently doing this.
