The industry has made significant advances in the way we exploit unconventional resources such as source rock and tight reservoirs. Innovations in horizontal drilling and multistage fracturing have unlocked previously uneconomical plays, and technology has brought a step change in operational efficiency. Lessons learned from unconventional resources highlight collaboration and integrated reservoir-centric workflows as common traits for economic success.
The development of unconventional resources in North America was aided by the readily available infrastructure, water resources, expertise, and a general understanding of potential sweet spots due to numerous well penetrations. Even with these favorable conditions, an estimated 40% of unconventional wells are uneconomical due to spatial variability in reservoir characteristics, lateral heterogeneity along the wellbores, accuracy of well placement, and variability in drilling, completion, and stimulation practices. This non-ideal economic performance also ineffectively consumes local resources such as water and proppant.
This paper provides a retrospective assessment of the Barnett Shale and Eagle Ford Shale to highlight lessons learned and the associated value of those learnings. The impact of applying technology and utilizing a data-driven approach based on measurements will be assessed in terms of the investment required to achieve a given hydrocarbon production. The results indicate that these unconventional plays could have been developed with well counts reduced by the thousands, water consumption reduced by billions of gallons, and investment savings in the billions of dollars if initially exploited by applying the key lessons learned from over the past 30 years. This potential reduction in investment amounts to $40 billion for the Barnett Shale (shale gas) plus the Eagle Ford Shale (oil window) and represents the significant value of moving along the learning curve. Fortunately, there is no need to repeat this learning curve investment, as key lessons learned can be applied to other unconventional plays around the world. This learning curve is of specific value in international plays where local infrastructure, supply, and market conditions may not be as favorable as in North America, hence necessitating a different approach to optimize the overall investment when developing unconventional plays.