EmptyTimCup
06-25-2012, 09:05 AM
Gasland’s Josh Fox Can’t Be Bothered with Facts
Oscar®-nominated filmmaker Josh Fox, he of the burning water tap, loves to scare people with the provocative word “fracking” and misleading images and claims of its potential to damage the environment, specifically groundwater.
To wit, this screenshot of a cute little animated .gif at Fox’s website gaslandthemovie.com.
It clearly depicts fractures from a horizontal gas well invading a freshwater aquifer. Scary! Now, consider the detail of that portion of the cartoon which depicts the fractures extending vertically up into the shallow water-bearing zone:
[graphic at link]
I came across an excellent presentation (http://ny.water.usgs.gov/projectsummaries/CP30/Marcellus_Presentation_Williams.pdf) (.pdf link) on the subject of Marcellus drilling and its potential to affect groundwater sources. The author is John H. Williams, a groundwater specialist with the U.S. Geological Survey who runs the New York Water Science Center in Troy, NY. I will steal a few of Mr. Williams’ images and refer to a few of his slides.
The image at left is a fair (not to scale!) depiction of a horizontal well, at left, versus a conventional vertical well on the right (click for a larger image). The subsurface is composed of a multitude of rock layers, only a few of which have potential for oil or gas development. Pressure increases with depth, and pressure is an important factor in exploiting gas, so most gas drilling in the Marcellus is at least 5,000 feet below the surface. (Williams’ slides 5 and 38 show the actual Marcellus shale at the surface, where it outcrops 100 miles or so north of the PA state line.)
Oil and gas operators are interested in understanding the mechanisms by which hydraulic fracturing works. To that end, they have employed microseismic imaging to map the propagation of an induced fracture while the frack job is in progress. The cracks and ruptures induced in the rock at depth can be recorded by arrays of surface microphones and mapped in three dimensions (Williams, slide 39).
Oscar®-nominated filmmaker Josh Fox, he of the burning water tap, loves to scare people with the provocative word “fracking” and misleading images and claims of its potential to damage the environment, specifically groundwater.
To wit, this screenshot of a cute little animated .gif at Fox’s website gaslandthemovie.com.
It clearly depicts fractures from a horizontal gas well invading a freshwater aquifer. Scary! Now, consider the detail of that portion of the cartoon which depicts the fractures extending vertically up into the shallow water-bearing zone:
[graphic at link]
I came across an excellent presentation (http://ny.water.usgs.gov/projectsummaries/CP30/Marcellus_Presentation_Williams.pdf) (.pdf link) on the subject of Marcellus drilling and its potential to affect groundwater sources. The author is John H. Williams, a groundwater specialist with the U.S. Geological Survey who runs the New York Water Science Center in Troy, NY. I will steal a few of Mr. Williams’ images and refer to a few of his slides.
The image at left is a fair (not to scale!) depiction of a horizontal well, at left, versus a conventional vertical well on the right (click for a larger image). The subsurface is composed of a multitude of rock layers, only a few of which have potential for oil or gas development. Pressure increases with depth, and pressure is an important factor in exploiting gas, so most gas drilling in the Marcellus is at least 5,000 feet below the surface. (Williams’ slides 5 and 38 show the actual Marcellus shale at the surface, where it outcrops 100 miles or so north of the PA state line.)
Oil and gas operators are interested in understanding the mechanisms by which hydraulic fracturing works. To that end, they have employed microseismic imaging to map the propagation of an induced fracture while the frack job is in progress. The cracks and ruptures induced in the rock at depth can be recorded by arrays of surface microphones and mapped in three dimensions (Williams, slide 39).