Abstract Scale inhibition is of crucial importance in harvesting geothermal energy, an attractive, renewable and sustainable energy source. The majority of the geothermal reservoir waters around the world contain a variety of anions and cations, which are prone to inorganic precipitation when subjected to drastic changes in both temperature and pressure, causing failures and unwanted shut-downs. Our goal is to prevent the formation, precipitation and deposition of such scales by stabilizing their respective components. Herein, the ability of a methacrylate-structured, grafted co-polymer, coined PEGPHOS-LOW (with polyethylene glycol and phosphonate grafts), to control inorganic precipitation is evaluated for four artificial geothermal brines of variable scaling propensity towards common geothermal scales, such as amorphous silica, magnesium, aluminum and iron silicates, zinc, lead and iron sulfides and calcium carbonate. Inhibitor selection was based on previous results obtained with four, similar inhibitor grafted co-polymers (one containing only polyethylene glycol, PEG, one with only phosphonate grafts, and two containing variable ratios of both grafts) against individual scales. The working brines were designed based on the saturated conditions of geothermal well fluids. PEGPHOS-LOW is a polymer that contains 34 PEG20 grafts, and 14 phosphonate grafts. It is a dual scale control additive, as it can function both as a scale inhibitor (keeping the scaling species soluble) and as a dispersant (keeping the scale particles formed in a suspended form). It displays a dosage-dependent scale inhibition and dispersion behavior, however, very high concentrations are necessary for satisfactory effectiveness, due to the high scaling propensity of the brines.

中文翻译：

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通用阻垢剂：在困难盐水压力下的双重抑制/分散性能评估

摘要 地热能是一种有吸引力的、可再生和可持续的能源，阻垢对于收集地热能至关重要。世界上大部分地热储层水都含有多种阴离子和阳离子，当温度和压力发生剧烈变化时，它们很容易发生无机沉淀，从而导致故障和意外停机。我们的目标是通过稳定它们各自的成分来防止这些水垢的形成、沉淀和沉积。在此，针对四种对常见地热尺度具有不同结垢倾向的人造地热盐水，评估了甲基丙烯酸酯结构的接枝共聚物、创造的 PEGPHOS-LOW（带有聚乙二醇和膦酸酯接枝物）控制无机沉淀的能力，例如无定形二氧化硅、镁、铝和铁的硅酸盐，锌、铅和铁的硫化物以及碳酸钙。抑制剂的选择是基于先前使用四种类似抑制剂接枝共聚物（一种仅含有聚乙二醇、PEG，一种仅含有膦酸酯接枝物，另一种含有两种接枝物的可变比率）针对个体尺度获得的结果。工作盐水是根据地热井液的饱和条件设计的。PEGPHOS-LOW 是一种包含 34 个 PEG20 接枝物和 14 个膦酸酯接枝物的聚合物。它是一种双重水垢控制添加剂，因为它既可以作为阻垢剂（保持水垢物质可溶），也可以作为分散剂（保持水垢颗粒以悬浮形式形成）。它显示出剂量依赖性的阻垢和分散行为，然而，