Unconventional energy extraction has been accompanied by a faster increase in aggregate wastewater generation compared with conventional practice. Understanding the extent to which it is due to technologies, energy production, or geological characteristics has implications for reducing the associated environmental risks. We analyze how wastewater generation patterns differ between unconventional wells and conventional wells, accounting for differences in well configurations and local geology. Using the 2008–2016 monthly production data from 50,039 wells, we show that unconventional wells generated more wastewater in the first 12 months of production but less cumulative discharge than conventional wells. Unconventional oil wells had a lower wastewater-to-energy ratio throughout their lifetime than their conventional counterparts, whereas no efficiency gap existed among gas wells. We find both an increasing initial discharge gap and growing efficiency gains between unconventional wells and conventional wells starting production in more recent years, likely due to increased penetration and persistent improvements of unconventional technologies over time. Our findings call for targeted strategies to balance the short-term disposal burden and the long-term efficiency gains of unconventional energy extraction.

与传统做法相比，非常规能源开采伴随着总废水产生的更快增长。了解它在多大程度上是由于技术、能源生产或地质特征造成的，这对于降低相关的环境风险具有重要意义。我们分析了非常规井和常规井之间废水产生模式的差异，考虑了井配置和当地地质的差异。使用来自 50,039 口井的 2008-2016 年月度生产数据，我们表明非常规井在生产的前 12 个月产生了更多的废水，但累积排放量低于常规井。与传统油井相比，非常规油井在其整个生命周期中的废水与能源比率较低，而气井之间不存在效率差距。我们发现，近年来非常规油井和开始生产的常规油井之间的初始排放间隙越来越大，效率提高也越来越大，这可能是由于随着时间的推移，非常规技术的渗透率增加和持续改进。我们的研究结果呼吁制定有针对性的战略，以平衡短期处置负担和非常规能源开采的长期效率收益。