Panel Discussion

Dew point pressure plays a critical role in the development of gas condensate reservoirs. Reserve estimation, production performance evaluation, and production systems design all are affected by dew point pressure. When reservoir pressure decreases below the dew point pressure, liquid drops out, and well productivity decreases rapidly. Therefore, estimation of dew point pressure is very essential for gas condensate reservoirs.

This paper is focused on the development of a new dew point pressure model. Data was collected from a number of different sources and subjected to a detailed filtration process. The data representing 715 gas condensate samples covering a wide range of gas compositions, at different pressures and reservoir temperatures. Industry methods for characterizing gas condensate based on total molecular weight and composition were tested and were found to be invalid. Theoretical and statistical analyses of the collected data were carried in order to develop a new model. This model relates the dew point pressure to gas composition, characterization of Heptane plus fraction, and reservoir temperature. It has an average absolute error, root mean square error, and coefficient of determination of 7.5%, 588, and 0.87, respectively. The proposed model has been compared to published correlations as well as an un-tuned equation of state, and it resulted in a better accuracy. The validity of the proposed model was tested against experimental data and equation of state simulations. It succeeded in capturing the physical trends associated with varying different input parameters.