"The technique itself is nothing new. Oil crews across the world have been schooled on its simple principles for generations: Identify aging, low-output wells and hit them with a blast of sand and water to bolster the flow of crude. The idea originated somewhere in the plains of the American Midwest, back in the 1950s.

But as today’s engineers start applying the procedure to the horizontal wells that went up during the fracking boom that swept across U.S. shale fields over the past decade, something more powerful, more financially rewarding is happening.

The short life span of these wells, long thought to be perhaps the single biggest weakness of the shale industry, is being stretched out. Early evidence of the effects of restimulation suggests that the fields could actually contain enough reserves to last about 50 years, according to a calculation based on Wood Mackenzie Ltd and ITG Investment Research data."

Dan Murtaugh, Lynn Doan, and Bradley Olson report for Bloomberg July 6, 2015. [2]