Zhang Xiaodong, Sun Alexander Y, Duncan Ian J
EES-16, Earth and Environmental Sciences, Los Alamos National Laboratory, Los Alamos, NM 87545, USA; Bureau of Economic Geology, Jackson School of Geosciences, The University of Texas at Austin, Austin, TX 78713, USA.
Bureau of Economic Geology, Jackson School of Geosciences, The University of Texas at Austin, Austin, TX 78713, USA.
J Environ Manage. 2016 Jan 1;165:188-198. doi: 10.1016/j.jenvman.2015.09.038. Epub 2015 Oct 2.
This work presents an optimization framework for evaluating different wastewater treatment/disposal options for water management during hydraulic fracturing (HF) operations. This framework takes into account both cost-effectiveness and system uncertainty. HF has enabled rapid development of shale gas resources. However, wastewater management has been one of the most contentious and widely publicized issues in shale gas production. The flowback and produced water (known as FP water) generated by HF may pose a serious risk to the surrounding environment and public health because this wastewater usually contains many toxic chemicals and high levels of total dissolved solids (TDS). Various treatment/disposal options are available for FP water management, such as underground injection, hazardous wastewater treatment plants, and/or reuse. In order to cost-effectively plan FP water management practices, including allocating FP water to different options and planning treatment facility capacity expansion, an optimization model named UO-FPW is developed in this study. The UO-FPW model can handle the uncertain information expressed in the form of fuzzy membership functions and probability density functions in the modeling parameters. The UO-FPW model is applied to a representative hypothetical case study to demonstrate its applicability in practice. The modeling results reflect the tradeoffs between economic objective (i.e., minimizing total-system cost) and system reliability (i.e., risk of violating fuzzy and/or random constraints, and meeting FP water treatment/disposal requirements). Using the developed optimization model, decision makers can make and adjust appropriate FP water management strategies through refining the values of feasibility degrees for fuzzy constraints and the probability levels for random constraints if the solutions are not satisfactory. The optimization model can be easily integrated into decision support systems for shale oil/gas lifecycle management.
这项工作提出了一个优化框架，用于评估水力压裂（HF）作业期间水资源管理的不同废水处理/处置方案。该框架兼顾了成本效益和系统不确定性。水力压裂推动了页岩气资源的快速开发。然而，废水管理一直是页岩气生产中最具争议且广为关注的问题之一。水力压裂产生的返排液和采出水（称为FP水）可能会对周边环境和公众健康构成严重风险，因为这种废水通常含有许多有毒化学物质和高浓度的总溶解固体（TDS）。FP水管理有多种处理/处置方案可供选择，例如地下注入、危险废水处理厂和/或再利用。为了经济高效地规划FP水管理措施，包括将FP水分配到不同方案以及规划处理设施的产能扩张，本研究开发了一个名为UO - FPW的优化模型。UO - FPW模型能够处理建模参数中以模糊隶属函数和概率密度函数形式表示的不确定信息。UO - FPW模型应用于一个具有代表性的假设案例研究，以证明其在实际中的适用性。建模结果反映了经济目标（即最小化系统总成本）与系统可靠性（即违反模糊和/或随机约束以及满足FP水处理/处置要求的风险）之间的权衡。如果解决方案不令人满意，决策者可以通过细化模糊约束的可行度值和随机约束的概率水平，使用所开发的优化模型制定并调整合适的FP水管理策略。该优化模型可以轻松集成到页岩油/气生命周期管理的决策支持系统中。
