If you live in or near the Dallas – Fort Worth area, you are no doubt aware of all the exploration, drilling and production of natural gas from the Barnett shale over the past several years. Few people, though, know about the process used to extract the gas from the rock formations through well bores drilled deep into the earth. Like me, most people are probably vaguely familiar with the old pump-jacks that dotted the Texas landscape in the 1970’s and 1980’s and pulled oil from wells that were typically drilled no deeper than 10,000 feet. Most of these wells were drilled vertically straight down and drew oil and gas from formations situated within a small radius of the well bore at the surface.
The gas wells drilled in the Barnett shale, Cotton Valley and Hainesville shales in East Texas and Louisiana and shale formations in Pennsylvania, the Dakotas and Wyoming, however, are very different from the old, vertical wells most of us grew up seeing. These wells are typically drilled vertical for several thousand feet and then angled to position the well bore horizontally for several thousand more feet within the bulk of the shale formation. When the well bore is drilled into the gas-containing shale, hydraulic fracturing is started to create breaks in the rock that allow gas to migrate from the rock and into the well for extraction.
While hydraulic fracturing has been around for over 60 years, the most recent controversy stems from possible contamination of water supplies from the chemicals used in the fracturing process or produced by the well that seeps into the water supply from the rock fractures created in the hydraulic fracturing process.
The information found at the links below discuss in more detail the complaints of residents who live near drilling activities and describe how Congress took the EPA out of the picture in 2005 for regulating hydraulic fracturing.
http://www.star-telegram.com/2010/07/01/2309237/denton-johnson-county-residents.html
http://gaslandthemovie.com/
