West Virginia University, Department of Geology & Geography, 330 Brooks Hall, 98 Beechurst Ave., Morgantown, WV 26506, USA.
Sandia National Laboratories, 4100 National Parks Highway, Carlsbad, New Mexico 88220, USA.
Environ Sci Process Impacts. 2021 Feb 4;23(1):28-47. doi: 10.1039/d0em00388c.
The most massive waste stream generated by conventional and unconventional hydrocarbon exploration is the produced water (PW). The costs and environmental issues associated with the management and disposal of PW, which contains high concentrations of inorganic and organic pollutants, is one of the most challenging problems faced by the oil and gas industry. Many of the current strategies for the reuse and recycling of PW are inefficient because of varying water demand and the spatial and temporal variations in the chemical composition of PW. The chemical composition of PW is controlled by a multitude of factors and can vary significantly over time. This study aims to understand different parameters and processes that control the quality of PW generated from hydrocarbon-bearing formations by analyzing relationships between their major ion concentrations, O, H, and Sr isotopic composition. We selected PW data sets from three conventional (Trenton, Edwards, and Wilcox Formations) and four unconventional (Lance, Marcellus, Bakken, and Mesaverde Formations) oil and gas formations with varying lithology and depositional environment. Using comparative geochemical data analysis, we determined that the geochemical signature of PW is controlled by a complex interplay of several factors, including the original source of water (connate marine vs. non-marine), migration of the basinal fluids, the nature and degree of water-mineral-hydrocarbon interactions, water recharge, processes such as evaporation and ultrafiltration, and production techniques (conventional vs. unconventional). The development of efficient PW recycle and reuse strategies requires a holistic understanding of the geological and hydrological history of each formation to account for the temporal and spatial heterogeneities.
常规和非常规碳氢化合物勘探产生的最大废物流是采出水 (PW)。PW 管理和处置相关的成本和环境问题是石油和天然气行业面临的最具挑战性的问题之一，因为 PW 含有高浓度的无机和有机污染物。目前 PW 的许多再利用和回收策略由于用水需求的不同以及 PW 化学成分的时空变化而效率低下。PW 的化学成分受多种因素控制，并且随时间变化很大。本研究旨在通过分析主要离子浓度、O、H 和 Sr 同位素组成之间的关系，了解控制含碳氢化合物地层生成的 PW 质量的不同参数和过程。我们选择了来自三个常规（特伦顿、爱德华兹和威尔科克斯地层）和四个非常规（兰斯、马塞勒斯、巴肯和梅萨维德地层）石油和天然气地层的 PW 数据集，这些地层具有不同的岩性和沉积环境。使用比较地球化学数据分析，我们确定 PW 的地球化学特征受到多种因素的复杂相互作用控制，包括水的原始来源（原生海水与非海水）、盆地流体的运移、水-矿物-烃相互作用的性质和程度、水补给、蒸发和超滤等过程，以及生产技术（常规与非常规）。开发有效的 PW 再循环和再利用策略需要全面了解每个地层的地质和水文历史，以考虑时空异质性。
