For years gas drilling companies and regulators have said that decades of hydraulic fracturing had not caused frack fluids to return from depth and reach aquifers. Now a British university study documents why fracking itself (as distinguished from spills at the surface or cementing failures during the drilling phase) has an excellent safety record.
The University of Durham's Energy Institute in the United Kingdom investigated hydraulic fracturing in America, Europe, and Africa by looking at thousands of induced fractures produced by "fracking" and found why hydraulic fracturing has not caused pollution of aquifers. The longest distance for any fracture was 588 meters. meters. http://www.platts.com/RSSFeedDetailedNews/RSSFeed/oil/8221049. Just 1% of the investigated fractures went as much as 350 meters. The lead researcher is Professor Richard J. Davies and the study is published in Marine and Petroleum Geology.
Simply put, fracking for shale gas is happening at such depths that there is next to no danger of polluting groundwater with fluids returning from depth. Fracking for shale gas happens in the USA typically 3,000 to 10,000 feet below any groundwater source, and the induced fractures don't travel anywhere near that distance.
Also it should be noted that this study further confirms that hydraulic fracturing is not a new technology and has been used around the world. As a result the British researchers were able to look at fracking and fractures on three continents. If fracking were causing groundwater contamination, such pollution would have shown up years ago all around the world.
It really is time to focus on the real threats to groundwater--spills and leaks at the surface and cementing errors that allow methane to migrate.
So, is hydraulic fracturing a 'new technology developed in response to energy demand' or is it a potentially dangerous old technology (this post says it is 'not new' that was only allowed to flourish in the US due to environmental regulations initially relaxed under the second Bush's 2nd term? The US press have consistently confused this question. It appears from this post that fracking is old and that the reason we see the boom of today is that regulations have changed, not technology. The public needs to understand this.
ReplyDeleteI'm not going to accept any study that tells me 'conclusively' that leaks under an area of square miles never go more than x distance vertically. There's just no way to know with any finality. Regardless, though, we know very well that cementing fails and fails spectacularly (gulf oil spill). 1000 minor failures that contaminate over centuries is just as bad if not worse, than such a single big one as the gulf spill.
Hydraulic fracturing is about 60 years old technology. Hundreds of Thousands of wells have been hydraulic fractured over decades.
ReplyDeleteThe fact that hydraulic fracturing has been widely used for decades is very important.
It is very important, because if frack fluids were returning from depth even in a small percentage of cases there would be massive water pollution already. The empirical record with this technology is huge. It is the best proof that frack fluids are not returning from depth, with the possible exception of Pavillion, Wyoming, where fracking was done within a couple hundred feet of the aquifer, an irresponsible practice, whether or not the fracking polluted that aquifer. Pavillion Wyoming is also not a shale gas field.
Cementing mistakes allow gas to migrate but have not allowed fluids or liquids to migrate. Again the factual, empirical record over decades and hundreds of thousands of wells prove this point.