The karst geothermal reservoir, Sinian Dengying Formation was investigated from the hydrogeochemical perspective. Integrated techniques including XRD + SEM, isotopes, saturation index and PHREEQC modeling were applied. With 37.3–72 ?, the targeted waters indicate low-mediate temperature geothermal reservoir. The CO₂ concentration in the geothermal waters varies from 1.2 mg/L to 52.42 mg/L, and the log(P_CO2) value ranges from −2.53 to −1.29, indicating an open carbonate system. A further D-¹⁸O stable isotope analysis addresses the geothermal waters are replenished by meteoric water from +815.52 m to +1427.78 m. Strong water-rock interactions are indicated by apparent ¹⁸O shift. The dominating hydrochemical type is SO₄·HCO₃-Ca·Mg with some Cl-Na. The CO₂-TDS-SI-Carbonates comprehensive analysis illustrate the origin of Ca²⁺, Mg²⁺, and HCO₃⁻, mainly from dolomite. The correlation of ¹⁸O-SO₄²-SI_Gypsum gives sound evidence for the processes of gypsum dissolution. Three inverse models were established and the results showed, that geothermal waters are controlled by two major factors: 1) the adjacent location to salt basin geological profiles with halite dissolution; and 2) the clay minerals such as Na-montmorillonite causing cation exchanges between Na⁺ and Ca²⁺ in the geothermal waters, resulting in excess of Na in relation to Cl concentrations.

从水文地球化学角度对震旦系灯影组岩溶地热储层进行了研究。应用了 XRD + SEM、同位素、饱和指数和 PHREEQC 建模等综合技术。目标水域温度为37.3~72℃，属于中低温地热储层。地热水中CO ₂浓度变化范围为1.2 mg/L至52.42 mg/L，log(P _CO2 )值变化范围为-2.53至-1.29，表明存在开放碳酸盐系统。进一步的 D- ¹⁸ O 稳定同位素分析表明，+815.52 m 至 +1427.78 m 范围内的地热水由大气水补充。^明显的18 O 位移表明强烈的水-岩石相互作用。主要的水化学类型是 SO ₄·HCO ₃ -Ca·Mg 和一些 Cl-Na。CO _{2 -TDS-SI-碳酸盐综合分析表明Ca} ²⁺、Mg ²⁺和HCO ₃ ^-的来源主要来自白云石。¹⁸ O-SO ₄ ² -SI_Gypsum的相关性为石膏溶解过程提供了可靠的证据。建立了三个反演模型，结果表明，地热水受两个主要因素控制：1）邻近盐盆地质剖面，有岩盐溶蚀；2)粘土矿物，例如Na-蒙脱石，引起Na ⁺和Ca ^{2+之间的阳离子交换}在地热水中，导致 Na 相对于 Cl 浓度过量。