Wet gas reservoirs are gaseous hydrocarbon systems that reside in reservoirs with the original temperatures above the cricondentherm. In addition, the field surface facilities, separators, gas plant, etc., are in the two-phase region of the system’s phase diagram. This is shown in Figure 2.17. Under these conditions, as the pressure in the reservoir is reduced due to production, the reservoir never enters the two-phase region of the gas and no hydrocarbon liquids drop out in the reservoir. That is, as pressure is reduced, the hydrocarbon fluid in the reservoir remains in its gaseous state. However, as the produced gas travels up the well and to the surface, at some point in the production system it enters the two-phase region of the phase envelope and liquid hydrocarbons develop in the well or surface facilities.