The ubiquitous natural sedimentary reservoirs and their high permeability have made the CO₂ plume geothermal system increasingly attractive. However, the complicated fluid-rock interactions during the geothermal exploitation can cause severe reservoir damage, constraining the excellent heat mining performance of the CO₂ and decreasing the possible applications of the CO₂ plume geothermal system. In order to analyze and solve this energy issue affecting the geothermal exploitation, in this study, a comprehensive numerical simulation model was established, which can consider formation water evaporation, salt precipitation, CO₂-water-rock geochemical reactions, and the changes in reservoir porosity and permeability in the CO₂ plume geothermal (CPG) system. Using this model, the geochemical reactions and salt precipitation and their effects on the geothermal exploitation were analyzed, and some measures were proposed to reduce the influence of fluid-rock interactions on the heat mining rate. The simulation results show that the gravity and the negative gas-liquid capillary pressure gradient induced by evaporation can cause the formation water to flow toward the injector. The back flow of the formation water results in salt precipitation accumulation in the injection well region, which can cause severe reservoir damage and consequent reductions to the heat mining rate. The CO₂-water-rock geochemical reactions could result in the dissolution of certain minerals and precipitation of others, but its minimal influence on the heat mining rate can be ignored. However, salt precipitation can affect the geochemical reactions by influencing the CO₂ flow and distribution, which can reduce the heat mining rate up to 2/5 of the original. Sensitivity studies show that the reservoir condition can affect the salt precipitation and heat mining rate, so a sedimentary reservoir with high temperature, high porosity and permeability, and low salinity should be selected for CPG application, with an appropriately high injection-production pressure difference. The injection of low salinity water before CO₂ injection and the combined injection of CO₂ and water vapor can be applied to reduce the salt precipitation and increase the heat mining rate in the CPG system.

无处不在的天然沉积物储层及其高渗透率使CO ₂羽状地热系统变得越来越有吸引力。然而，地热开采过程中复杂的流体-岩石相互作用会导致严重的储层破坏，从而限制了CO ₂优异的热采性能，并降低了CO ₂羽状地热系统的可能应用。为了分析和解决影响地热开发的能源问题，本研究建立了一个综合的数值模拟模型，该模型可以考虑地层水蒸发，盐分沉淀，CO _2-水-岩石地球化学反应以及储层变化。一氧化碳的孔隙率和渗透率₂羽地热（CPG）系统。利用该模型，分析了地球化学反应，盐分沉降及其对地热开采的影响，提出了减少液-岩相互作用对热采速率的影响的措施。模拟结果表明，重力和蒸发引起的负的气液毛细管压力梯度会导致地层水流向注入器。地层水的回流会导致盐析物在注入井区域中积聚，这可能导致严重的储层破坏并因此降低热量采出率。一氧化碳₂-水-岩石地球化学反应可能导致某些矿物的溶解和其他矿物的沉淀，但其对热采速率的最小影响可以忽略。但是，盐分的沉淀会通过影响CO _2的流量和分布而影响地球化学反应，这可能使热采速率降低至原来的2/5。敏感性研究表明，储层条件会影响盐分的析出和热量的开采速度，因此，CPG应用应选择具有高温，高孔隙度，高渗透率，低盐度的沉积储层，并具有较高的注采压力差。注入CO ₂之前先注入低盐度水，再注入CO _2。 可以使用水蒸气减少CPG系统中的盐分沉淀并提高热采率。