Optimisation of the use of commonly available energy sources through seasonal storage of excess heat in hot deep aquifers is considered. The chemical effects of heating the Bunter Sandstone Formation to up to 150 °C are investigated by laboratory core flooding experiments at reservoir conditions, petrographic analysis and geochemical modelling. Experiments are performed with a Ca-depleted synthetic formation water in order to avoid loss of injectivity by calcium carbonate scaling at elevated temperatures. The synthetic formation water is injected into a Bunter Sandstone Formation sample at 25 °C, 75 °C (reservoir temperature), 100 °C and 150 °C with a velocity of 0.05 PV/h. Results show a significant increase in the aqueous concentration of calcium, silicium and barium upon heating, while the concentration of magnesium decreases. The main chemical processes taking place upon heating of the reservoir to up to 150 °C is dolomitisation, the replacement of plagioclase with albite, the dissolution of quartz and barite and the precipitation of mica. A significant portion of the cementing calcite dissolved during the experiment, and consequently the tested Bunter Sandstone sample disintegrated after the experiment, indicating that injection of heated calcium depleted Bunter brine into the Bunter Sandstone Formation may damage the reservoir. The results highlight the importance of investigating the effects that removal of selected ions may have on the reservoir properties, since the injection of modified formation water may cause new problems in the reservoir.

考虑通过在热的深层含水层中季节性储存多余热量来优化常用能源的使用。通过在储层条件下进行实验室岩心驱油实验、岩相分析和地球化学建模，研究了将邦特砂岩地层加热至 150 °C 的化学效应。实验是用贫钙的合成地层水进行的，以避免在升高的温度下碳酸钙结垢造成注入能力的损失。将合成地层水以 0.05 PV/h 的速度注入到 25 °C、75 °C（储层温度）、100 °C 和 150 °C 的邦特砂岩地层样品中。结果显示加热后钙、硅和钡的水溶液浓度显着增加，而镁的浓度降低。将储层加热至 150 °C 时发生的主要化学过程是白云石化、钠长石替代斜长石、石英和重晶石的溶解以及云母的沉淀。很大一部分胶结方解石在实验过程中溶解，因此测试的邦特砂岩样品在实验后分解，表明将加热的贫钙邦特盐水注入邦特砂岩地层可能会损坏储层。结果强调了研究去除选定离子可能对储层性质产生的影响的重要性，因为注入改性地层水可能会在储层中引起新的问题。钠长石取代斜长石，石英和重晶石溶解，云母沉淀。很大一部分胶结方解石在实验过程中溶解，因此测试的邦特砂岩样品在实验后分解，表明将加热的贫钙邦特盐水注入邦特砂岩地层可能会损坏储层。结果强调了研究去除选定离子可能对储层性质产生的影响的重要性，因为注入改性地层水可能会在储层中引起新的问题。钠长石取代斜长石，石英和重晶石溶解，云母沉淀。很大一部分胶结方解石在实验过程中溶解，因此测试的邦特砂岩样品在实验后分解，表明将加热的贫钙邦特盐水注入邦特砂岩地层可能会损坏储层。结果强调了研究去除选定离子可能对储层性质产生的影响的重要性，因为注入改性地层水可能会在储层中引起新的问题。因此，测试后的邦特砂岩样品在实验后分解，表明将加热的贫钙邦特盐水注入邦特砂岩地层可能会损坏储层。结果强调了研究去除选定离子可能对储层性质产生的影响的重要性，因为注入改性地层水可能会在储层中引起新的问题。因此，测试后的邦特砂岩样品在实验后分解，表明将加热的贫钙邦特盐水注入邦特砂岩地层可能会损坏储层。结果强调了研究去除选定离子可能对储层性质产生的影响的重要性，因为注入改性地层水可能会在储层中引起新的问题。