Fueled by a culture of innovation, hydraulic fracturing has transformed the energy landscape from inside North America out. But achieving that paradigm shift took years of improving subsurface understanding, technology development, and fine-tuning the completions practice through trial and error. Authors from Liberty Oilfield Services set out to document this evolution in SPE 194345 as they took a deep dive into fracturing history. Their paper traces the advancements in fracturing study and deployment from its earliest days to the present. Fracturing first took place in 1947 and has grown exponentially in uptake over the past 2 decades. The result has been the shale revolution, which has catapulted the US to at or near the top of the world in both crude oil and natural gas production. Between 2000âjust after fracturing pioneer Mitchell Energy began commercial shale productionâand 2018, yearly US dry gas production went to 83 Bcf/D from 53 Bcf/D while US crude output climbed to just under 11 million B/D from 5.8 million B/D, according to data from the US Energy Information Administration. Once largely dependent on imports, the country has become a net gas exporter and oil exports are reaching new heights. During that same period, increased fracturing intensity and a better knowledge of the subsurface complexities associated with the completions practice resulted in North American pressure pumping horsepower rising tenfold, yearly frac stage count growing twentyfold, and proppant mass pumped jumping fortyfold. Since the turn of the millennium, âthe difference has really become that we bring the frac down to the hydrocarbon molecule in the rock,â said Leen Weijers, vice president of engineering at Liberty Oilfield Services, at the recent SPE Hydraulic Fracturing Technology Conference in The Woodlands, Texas. âWe do that with multistage horizontal wells and a focus on complexity, creating a plumbing system that is two miles long and maybe half-a-mile-wide and maybe 500 ft in height.â Background: Mineral Rights, Fracture Study Weijers et al. first noted the importance of private mineral ownership in spurring unconventional development in the US. Mineral owners can develop, borrow against, or sell their land, meaning they have a direct stake in the high-risk, high-reward mineral development game. As the industry became more aware of the gas and oil recovery potential from shale, small independents began scooping up acreage, benefitting from their familiarity with the communities in which they operated or planned to operate. A major step forward in understanding the subsurface impact of hydraulic fracturing, Weijers et al. said, came with the realization by Warpinski et al. (1991) that fractures are complex, with dozens of parallel fractures growing simultaneously during a job in a narrow, 20â40 ft-wide zone. This dispelled the previous belief that simple bi-wing fractures extended from the wellbore, stimulating further study of fracture growth.