According to this research study by the EPA published June 2010, 'fracturing is a well stimulation process used to maximize the extraction of oil, natural gas or geothermal energy.' The Saturday Essay of April 2, 2011, in the Wall Street Journal entitled Stepping on the Gas by Daniel Yergin, piqued my interest in the topic. I realized I had seen or heard the word for the terminology countless times, but I really had no clear idea what the science and technology was behind it. As with most things, understanding is an essential part of being able to make informed decisions. And this issue certainly begs for that.
With any of the following publications, consider the context and the source. The intent of this diary is to illustrate the basic process and does not necessarily agree with the claims of the articles.
A little history of the technology taken from the WSJ article ...
In the early 1980s, George P. Mitchell, a Houston-based independent energy producer, could see that his company was going to run out of natural gas. Mr. Mitchell's company was contracted to deliver a substantial amount of natural gas from Texas to feed a pipeline serving Chicago. But the reserves on which he depended were running down, and it was not at all clear where he could find more gas to replace the depleting supply.According to the author Daniel Yergin...
Perhaps the natural gas that was locked into shale could be freed and made to flow. The laboratory for his experiment was a sprawling geologic formation called the Barnett Shale around Dallas and Fort Worth. The payoff came a decade and a half later, at the end of the 1990s. Using a specialized version of a technique called hydraulic fracturing (now widely known as "fracking" or "fracing"), his team found an economical way to create or expand fractures in the rock and to get the trapped gas to flow.
As late as 2000, shale gas was just 1% of American natural gas supplies. Today, it is about 25% and could rise to 50% within two decades. Estimates of the entire natural gas resource base, taking shale gas into account, are now as high as 2,500 trillion cubic feet, with a further 500 trillion cubic feet in Canada. That amounts to a more than 100-year supply of natural gas.
Two illustrations of the process...
From the EPA study, drilling is done to the rock layer followed by a horizontal turn to follow the layer.
Large amounts of water, sand, and chemicals are needed. The wastewaters from the drilling and fracturing process require proper disposal. Public concerns and potential risks of contamination of water supplies appear in many reports. A closer view from ProPublica adds some detail to the basic plan.
The NY Times published this 8 part interactive which looked at the process and hazards of hydraulic fracturing. Halliburton's website offers an interactive as well
Finally, this video shows the process as vividly as any I have seen.
0 comments:
Post a Comment