Fracking increasingly being used to recover Oil.

[PoliticAverse]

A new drilling technique is opening up vast fields of previously out-of-reach oil in the western United States, helping reverse a two-decade decline in domestic production of crude.
...
Oil engineers are applying what critics say is an environmentally questionable method developed in recent years to tap natural gas trapped in underground shale. They drill down and horizontally into the rock, then pump water, sand and chemicals into the hole to crack the shale and allow gas to flow up.

Read the rest: http://news.yahoo.com/s/ap/20110209/ap_on_re_us/us_shale_oil