PHASE DIAGRAMS CAN LOCATE GAS-CONDENSATE-WELL CORROSION.

Phase diagrams that show regions where different phase combinations are in equilibrium help answer many questions in a gas-condensate well void of formation water. Typical questions might be: Is there only the vapor phase present or is there really a condensed water-rich liquid in equilibrium with the vapor phase? Are there really two condensed liquid phases in equilibrium with the vapor phase, both a water-rich liquid and a hydrocarbon-rich liquid? If an inhibitor is added, will the inhibitor cause a new hydrocarbon-rich liquid to appear or does it alter the hydrocarbon-rich liquid already present? The phase diagram regions are shown as functions of temperature and pressure; hence, the pressure-temperature profile of the well can be added to the associated phase diagram to see what phase combinations are possible throughout the well string. Deductions can then be made to determine where corrosion problems are likely to occur and what actions are possible to reduce corrosion.