Machine-Learning-Based Development of Regional PVT Correlations for Bubble-Point Pressure and Solution Gas-Oil Ratio for Western Kazakhstan Oilfields
Corresponding author: Adel Sarsenova
Abstract
Bubble-point pressure and solution gas-oil ratio are critical PVT properties that govern phase behavior, reservoir performance, and the accuracy of material balance, production forecasting, and numerical simulation studies. Existing empirical correlations have historically been calibrated using geographically limited datasets, resulting in significant prediction errors when applied to crude oils with different compositional and geological characteristics, such as those found in Kazakhstan. This study investigates the performance of widely used global correlations in an extensive set of Kazakhstan oilfield data and demonstrates their systematic limitations. To address these shortcomings, new regional correlations were developed for bubble-point pressure and solution gas-oil ratio using a machine-learning-assisted workflow. Symbolic regression was employed to derive an explicit analytical expression for the solution gas-oil ratio, while multivariate log-linear regression was used to formulate a physically interpretable correlation for bubble-point pressure. Both models were evaluated using industry-standard error metrics and compared with established global correlations. The newly developed regional correlations exhibit substantially lower prediction errors and markedly improved consistency across the full range of fluid properties. These findings highlight the importance of region-specific PVT model development and provide more reliable tools for reservoir engineering applications in settings where laboratory data are limited or incomplete.
Keywords:
machine-learning-assisted regression, bubble-point pressure, solution gas-oil ratio, PVT correlations, Kazakhstan oilfields, log linear regression, reservoir engineeringReferences
S. A. Farkha, M. H. S. Zangana, and O. Shoham, "Evaluation of compositional models and PVT correlations for Iraqi light crude oils properties," Energy Science & Engineering, vol. 11, no. 7, pp. 2654–2667, July 2023.
M. A. Al-Marhoun, "Evaluation of empirically derived PVT properties for Middle East crude oils," Journal of Petroleum Science and Engineering, vol. 42, no. 2, pp. 209–221, Apr. 2004.
M. E. Dokla and M. E. Osman, "Correlation of PVT Properties for UAE Crudes," SPE Formation Evaluation, vol. 7, no. 01, pp. 41–46, Mar. 1992.
A. M. Elsharkawy, A. A. Elgibaly, and A. A. Alikhan, "Assessment of the PVT correlations for predicting the properties of Kuwaiti crude oils," Journal of Petroleum Science and Engineering, vol. 13, no. 3–4, pp. 219–232, Nov. 1995.
M. Q. A. Talib and M. S. Al-Jawad, "Assessment of the Common PVT Correlations in Iraqi Oil Fields," Journal of Petroleum Research and Studies, vol. 12, no. 1(Suppl.), pp. 68–87, Apr. 2022.
S. S. Ikiensikimama and O. Ogboja, "Assessment Of Bubblepoint Oil Formation Volume Factor Empirical PVT Correlations," Global Journal of Pure and Applied Sciences, vol. 15, no. 1, 2009.
O. Olatunji and J. Mogbolu, "A Novel Algorithmic Design and Implementation for Predicting Crude-Oil PVT Properties," presented at the SPE Nigeria Annual International Conference and Exhibition, Aug. 2020.
B. Khussain et al., "The Delumping Method as a Key Factor in obtaining a characterized Hydrocarbon Fluid using the Example of Kazakhstani Oil," Engineering, Technology & Applied Science Research, vol. 15, no. 1, pp. 19743–19748, Feb. 2025.
Z. Alisheva et al., "Modeling and analysis of filtration processes in oil reservoirs of small fields by reserves," Scientific Reports, vol. 15, no. 1, Apr. 2025, Art. no. 11555.
R. B. Gharbi, A. M. Elsharkawy, and M. Karkoub, "Universal Neural-Network-Based Model for Estimating the PVT Properties of Crude Oil Systems," Energy & Fuels, vol. 13, no. 2, pp. 454–458, Mar. 1999.
L. S. Al-Jaff and S. M. Hamd-Allah, "PVT Modeling of Qaiyarah Oil Field," Journal of Engineering, vol. 30, no. 10, pp. 122–133, Oct. 2024.
M. Riyahin, G. M. Montazeri, L. Jamoosian, and F. Farahbod, "PVT-generated Correlations of Heavy Oil Properties," Petroleum Science and Technology, vol. 32, no. 6, pp. 703–711, Mar. 2014.
D. A. Otchere, T. O. Arbi Ganat, R. Gholami, and S. Ridha, "Application of supervised machine learning paradigms in the prediction of petroleum reservoir properties: Comparative analysis of ANN and SVM models," Journal of Petroleum Science and Engineering, vol. 200, May 2021, Art. no. 108182.
A. K. Patidar, S. Singh, S. Anand, and P. Kumar, "Enhancing PVT property predictions for black oil reservoirs through the application of supervised machine learning techniques," Geoenergy Science and Engineering, vol. 243, Dec. 2024, Art. no. 213307.
K. Uzogor and O. Akinsete, "Improved Correlations and Predictive Models for Nigerian Crude Oil Pvt Properties Using Advanced Regression and Intelligent Techniques," in SPE Nigeria Annual International Conference and Exhibition, Aug. 2020, Art. no. D013S004R006.
S. S. Ikiensikimama and O. Ogboja, "Review Of PVT Correlations For Crude Oils," Global Journal of Pure and Applied Sciences, vol. 14, no. 3, pp. 331–337, Oct. 2008.
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Copyright (c) 2026 Adel Sarsenova, Mariam Kumarkhan, Abdulakhat Ismailov

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