There are some early signs that the U.S. shale industry is starting to show its age, with depletion rates on the rise. A study from Wood Mackenzie found that some wells in the Permian Wolfcamp were suffering from decline rates at or above 15 percent after five years, much higher than the 5 to 10 percent originally anticipated. “If you were expecting a well to hit the normal 6 or 8 percent after five years, and you start seeing a 12 percent decline, this becomes more of a reserves issue than an economics issue,” said R.T. Dukes, a director at industry consultant Wood Mackenzie Ltd., according to Bloomberg. As a result, “you have to grow activity year over year, or it gets harder and harder to offset declines.” Moreover, shale wells fizzle out much faster than major offshore oil fields, which is significant because the boom in shale drilling […]