In the southern part of the CP-I area, the fluid in the shallower reservoir is being intensely diluted by the entry of cold groundwater that flows horizontally but also vertically, as described byRodríguez et al. (2000), based on results of chloride and isotope tracer data from the reinjection fluid. This evidence supports a conclu-sion that a hydraulic communication between them occurs, where the deeper reservoir feeds hot fluids to the shallower reservoir. Due to the natural recharge that occurs in this zone and also to the reinjection returns, the production wells do not exhibit excess steam values. In
contrast, the values are calculated to be negatives toward the east, indicating decreases in gas contents in the produced fluids