U.S tight oil production from shale plays will fall more quickly than most assume.  Why?  High decline rates from shale reservoirs is given. The more interesting reasons are the compounding effects of pad drilling on rig count and poorer average well performance with time.   Rig productivity has increased but average well productivity has decreased. Every rig used in pad drilling has approximately three times the impact on the daily production rate as a rig did before pad drilling.  At the same time, average well productivity has decreased by about one-third.  This means that production rates will fall at a much higher rate today than during previous periods of falling rig counts. Most shale wells today are drilled from pads.  One rig drills many wells from the same surface location, as shown in the diagram below. (click image to enlarge) The Eagle Ford Shale play in South Texas is one of the […]