Comparison and Validation of Theoretical and Empirical Correlations for Black Oil Reservoir Fluid Properties

摘要

Characterization of reservoir fluids is important for developing a strategy to manage the reservoir production scheme effectively and efficiently. Reservoir fluid properties (e.g., density, viscosity, gas/oil ratio, bubble-point pressure, compressibility, and formation volume factor) are crucial for both reservoir and petroleum engineering; they are the fundamental inputs for material balance calculation, determination of oil reservoir volumes, and estimation of oil recovery with the use of a reservoir simulator. Ideally, the reservoir fluid properties are determined from laboratory studies on the bottomhole samples or on the recombined separator oil and gas samples. When only field measurements or limited laboratory data are available, empirical black oil correlations can be used to determine the essential fluid properties without the knowledge of fluid compositions. In the past few decades, with large sets of petroleum fluid data at various reservoir conditions and properties, the development of black oil correlations for pressure-volume-temperature (PVT) analysis study has been researched extensively. Consequently, numerous correlations that are applicable to various types of oil have been proposed and published. In this paper, we compare and provide guideline for the various correlations that were used to determine the black oil fluid properties.rnFor this study, more than 30 theoretical and empirical black oil correlations for bubble-point pressure, gas/oil ratio and oil formation volume factor were reviewed and validated; variations of the calculated fluid properties versus input parameters were studied and compared across the stated ranges of applicability. The comparison results are presented graphically. The correlations of this study are also summarized in tables that can be used to guide PVT users in selecting the most appropriate black oil correlation for specific reservoir fluids and conditions.