PERFORMANCE EVALUATION OF EXPERIMENTAL AND SIMULATED PVT TESTS OF OIL SAMPLES FOR LOWER GURU FORMATION

In the petroleum industry pressure-volume-temperature (PVT) analysis and behavior of oil & gas condensate reservoirs depend on pressure, volume, fluid composition, temperature, and behavior in the phase envelope. The best way to calculate the performance of a reservoir, one of the key parameters for performance of any reservoir is the PVT properties, which are either important for the material balance, reserves estimation, reservoir performance prediction, enhanced oil recovery scheme, production system design and optimization. Through the laboratory experiment of reservoir fluids, the PVT properties can be calculated, but this laboratory experimental work can be expensive and it is not available easily all the time during the evaluation of reservoir fluids. So we have an alternate way to calculate various reservoir fluid properties through the use of available exiting empirical correlations. This study adopts the most frequently used pressure-volume-temperature (PVT) empirical correlations used in industry. These correlations were evaluated based on performance for oil samples of the Lower Guru Formation located in Pakistan. A total of 09 PVT reports were used in this work to study the performance of the popular PVT correlations to estimate some of the PVT properties for Pakistani based light oil such as bubble point pressure (Pb), gas solubility (Rs), and formation volume factor (Bo), at and below the bubble point pressure. The samples were originally collected from three different wells of a single field. The field is located in the upper guru formation. And data were obtained from laboratory analysis (PVT routine tests) Constant Composition Expansion and Differential Liberation tests respectively. The experimental results were then used in available empirical correlations. Finally, the evaluation is performed based on statistical error analysis (SEA), suitable correlations for field applications are recommended for estimating gas solubility, bubble point pressure, and oil formation volume factor (FVF).