The unconventional oil boom and off-the-chart production increases that occurred between 2008 and 2014 in the U.S. were driven mostly by technology, and chief among these technologies were horizontal drilling (which allowed E&P operators to follow the prevailing formations laterally), hydraulic fracturing (which allowed the operators to increase the permeability and porosity of tighter geologic formations), and the use of proppant (sand and fluid designed to keep the fractured pathways to the wellbore open).
The high price of oil during that period kept broad experimentation economically feasible, and the nature of the financing game kept most operators focused on the huge gains available in initial production, perhaps even at the expense of steeper decline rates.
