Vandenberghe et al. obtained fluid samples from the Merksplas-Beerse geothermal well drilled into a karstic limestone section of the Dinantian reservoir. The reservoir fluid showed a high dissolved gas content. Chemical analyses were performed on several water samples obtained either at the gas separator outlet, from a corrosion test loop, or downhole samples. The water analyses on downhole samples and the gas composition of five gas samples, GLR, and measured bubble point pressure at 73.9⁰C are shown in Table : To calculate the bubble point pressure using PHREEQC, a solution and gas phase consistent with the specifications in Table are defined and equilibrated at the experimental temperature and increasing pressure values. Since the composition of the two downhole samples is slightly different, we calculated the bubble point pressure considering both the composition of the "S1" and "S2" samples. The calculated bubble pressures are shown together with the experimental values in Figure . PHREEQC and Reaktoro lead to similar bubble point pressures and, except for two of the gas samples, which is in good agreement with the experimental results.