By Jim Forsyth

SAN ANTONIO, Texas (Reuters) - The Eagle Ford shale oil and natural gas field in south Texas could turn out to be the largest recoverable oil deposit ever found in the Lower 48 states, according to a study released on Wednesday.

The liquids-rich Eagle Ford shale, one of the hottest North American shale fields, could generate $25 billion in economic development in 2011 and support 47,000 local jobs, according to the study by the Center for Community and Business Research at The University of Texas at San Antonio's Institute for Economic Development.

From 2010 to 2011, crude oil production increased more than six-fold to over 28 million barrels, condensate production tripled to over 21 million barrels, and natural gas production doubled, according to the study, which was funded by America's Natural Gas Alliance, an industry group.

"The total number of recoverable reserves for the Eagle Ford shale is still unknown, but there are estimates that it could be as much as 7 to 10 billion barrels," said Thomas Tunstall, lead author of the study. "That would make it the largest on-shore oil reserve ever discovered in the Lower 48 states."

The liquids-rich Eagle Ford shale play in Texas is one of the hottest North American shale fields, as oil prices have remained strong relative to natural gas prices, which have slumped to a decade low.

The top three Eagle Ford operators in 2011 (ranked by completed oil wells) were EOG Resources Inc., Cheasapeake Energy Corp. and Burlington Resources, the study said.

The Eagle Ford is the largest in what are referred to as 'hydraulic fracturing' or 'fracking' fields, in which crews bombard hard shale rock with water and other chemicals to reach oil reserves which previously were not recoverable. Fracking is a controversial practice, with several environmental groups claiming it damages water supplies.

Oil industry executives said wells producing $100,000 a week in income are not unusual in the Eagle Ford.

"We are evaluating a series of projects in that regard that could literally double our company's earnings over the next few years," said Curt Anastasio, the President and CEO of San Antonio based NuStar Energy.

(Editing by Chris Baltimore; Editing by Alden Bentley)