Experimental results on barium transport in dolomite are used to formulate, calibrate, and validate a reactive transport model of produced water disposal into dolomite saline aquifers. The model accounts for sorption, dissolution/precipitation reactions of minerals (dolomite, calcite, barite, gypsum, and witherite) and complexation and acid-base reactions of most abundant ionic species (H⁺, HCO₃⁻, SO₄²⁻, Ca²⁺, Mg²⁺, and Cl⁻) in produced waters including Ba²⁺ which is the most common and abundant heavy metal present in produced water from oil and gas reservoirs. The model is applied to determine the chemical controls of barium transport in Arbuckle dolomite aquifers. The simulated scenario corresponds to produced water disposal through a Class II injection well located near an abandoned well that can facilitate the transport of barium to underground sources of drinking water (USDW). Simulation results reveal that most suitable dolomite aquifers to prevent the contamination of USDW by barium are dolomite aquifers of high SO₄²⁻ content (>1000 mg/L). The mobility of barium which is promoted by the formation of Ba(Cl)⁺ and competition of cations (Ca²⁺ and Mg²⁺) for hydration sites of dolomite can be suppressed by the precipitation of barium as barite in dolomite saline aquifers of high SO₄²⁻ content. A sensitivity analysis conducted using a two-level factorial design of experiments indicates that barium transport can be controlled by the initial concentration of a single ionic specie (mostly SO₄²⁻) or the concentration of various ionic species (e.g., SO₄²⁻, Cl⁻, and Mg²⁺). This depends on the chemical composition of both the dolomite saline aquifer and injection produced water. This work highlights the potentiality of a reactive transport simulation approach to conduct compatibility analysis of dolomite saline aquifers and produced waters to select dolomite aquifers and/or decide on treatment methods to prevent the contamination of USDW by barium.

钡在白云石中的运移实验结果被用来制定，校准和验证反应水运移到白云石盐水层中的反应运移模型。该模型考虑了矿物的吸附，溶解/沉淀反应（白云石，方解石，重晶石，石膏，和毒重石）和（最丰富的离子物质的络合和酸-碱反应ħ ⁺，HCO ₃ ^-，SO ₄ ^2-，钙²⁺，镁²⁺和Cl ^- ）中制备水域含有Ba ²⁺它是油气储层采出水中存在的最常见和最丰富的重金属。该模型用于确定Arbuckle白云岩含水层中钡运移的化学控制。模拟场景对应于通过位于废弃井附近的II类注入井进行采出水处置，该注入井可以促进钡向地下饮用水源（USDW）的运输。模拟结果表明，最适合防止钡污染USDW的白云岩含水层是高SO ₄ ^2-含量（> 1000 mg / L）的白云岩含水层。Ba（Cl）⁺的形成和阳离子（Ca ²⁺和Mg ²⁺）可以通过在高SO ₄ ^2-含量的白云石盐质含水层中钡作为重晶石的沉淀来抑制白云石的水合位点。使用两级因子设计进行的敏感性分析表明，钡的迁移可以通过单个离子物种的初始浓度（主要是SO ₄ ^2-）或各种离子物种的浓度（例如SO ₄ ^{2-）来控制。}，氯^-和Mg ²⁺）。这取决于白云石盐水层和注入采出水的化学成分。这项工作强调了反应性运输模拟方法对白云岩盐水层和采出水进行相容性分析以选择白云岩含水层和/或确定处理方法以防止USDW受到钡污染的潜力。