Hydraulic Fracturing -- Fracking --

From PennEnergy:

What is the process of extracting natural gas from deep shale formations supposed to be called in its condensed version? Is it fracing or fracking? How about fraccing? Frac, frac-out and frac job also have been bandied about.

Fracking seems to be the short choice among most folks, although some industry officials and online media bloggers tend to favor fracing. But, fracing makes it appear the term rhymes with tracing when it actually rhymes with tracking.

Fracturing, fracing, fracking? In the end, it’s only a word.

I am attempting to be consistent throughout the site, and use the "k" when appropriate.  The AP style book and Modern Language Association will eventually sort this out. My hunch: the "k" will win out. 

I originally posted on this some time ago; one can find more at FAQ and scroll down to #34.