The latest EIA drilling productivity report (11th April 2016) https://www.eia.gov/petroleum/
Figure 1: Eagle Ford production change from old/new wells
Figure 2: EIA drilling productivity report April 2016
More details can be found here: http://crudeoilpeak.info/us-sh
The following article describes how desperate the situation is: As U.S. shale drillers suffer, even the bankrupt keep pumping oil http://mobile.reuters.com/arti