Improvement in MMP Predictions Using Paraffin Number

A high degree of accuracy is required for predicting the outcome of the gas injection process due to the high cost associated in the gas injection operation. Such accuracy includes preliminary screening parameters for gas miscible displacement, minimum miscibility pressure (MMP). Empirical correlations were often used to predict the MMP during the preliminary study. The aim of this study was to reduce the error of the prediction by the correlation. This study suggests incorporating the parafinicity factor into the correlation to further characterize the oil composition and reduce the error. For this purpose, a total of 79 MMP measurements from the literature and 4 measurements of MMP from this study were used to assess the Yuan (2004), Glaso (1985) Cronquist (1977) and Yellig (1980) correlations. Parafinicity factor was used to measure the limit of parafinicity that can fit in the correlations and to improve the correlation. It was demonstrated in this study that Yuan and Yellig correlations predictions will give huge error of predictions. In contrast, Glaso correlation was suitable for crude that has parafinicity factor value of more than 11.6 while Cronquist correlation was suitable for crude that has parafinicity factor value of more than 11.74 as the error was less significant. This indicates that Glaso and Cronquist correlations were applicable to paraffinic crude compared to asphaltenic crude. Glaso correlation can be further improved by including the parafinicity factor and reduce the average deviation error to 9.49% from 12.23%.