New approach for compaction prediction in oil reservoirs

• Javier Fernando Mendoza Molina Universidad Industrial de Santander.
• Zuly Himelda Calderón Carrillo Universidad Industrial de Santander.
Keywords: Pore pressure, Production, Mathematical model, Numerical simulation, Flow equations

Abstract

As reservoir fluids are produced, pore pressure decreases and compacting rock loses capacity to support the overburden pressure, while the effective stress increases rapidly leading to pore collapse. Reservoir can elastically compact itself until pore pressure drops to the elastic limit, then initiates a plastic deformation known as mechanical compaction. Using numerical models is a good tool for compaction prediction; as they can predict reservoir behavior. This paper is purported by some models that allow providing for an approximate representation and prediction of the compaction magnitude at the wellbore developed in oil reservoirs during production (another model could be used to amplify the range until reservoir limits), integrating a uniaxial compaction mathematical model with pressure drawdown equation in formation face, and then a numerical model is built aimed reproducing the phenomenon and its changes over time. The mathematical model is built with the uniaxial compaction model and the drawdown pressure equation. The model is not complex but integrates the mean variables and rock properties involved in compaction phenomenon, like rock compressibility, elastic modulus, porosity, permeability and fluid pressure. This paper develops new numerical model based on the foundations of the Geertsma (1973) model, adding a step-by-step procedure to calculate the new rock properties over time, in order to have a more realistic compaction magnitude result.

References

Best, K. (2002). Development of an integrated model for compaction/water driven reservoirs and its application to the J1 and J2 Sands at Bullwinkle, Green Canyon Block 65, deepwater Gulf of Mexico. M. Sc. Thesis, Petroleum and Natural Gas Engineering, The Pennsylvania State University, Pennsylvania, 294pp.

Carman, P. C. (1956). Flow of gases through porous media. London: Butterworths Scientific Publications.

Comisky, J. (2002). Petrophysical analysis and geologic model for the Bullwinkle J Sands with implications for time-lapse reservoir monitoring, Green Canyon Block 65, offshore Louisiana. M. Sc. Thesis, Geosciences, The Pennsylvania State University, Pennsylvania, 134pp.

Fjaer, E., Holt, R. M., Horsrud, P., Raaen, A. M. & Risnes, R. (2008). Petroleum related rock mechanics. (2). Amsterdam: Elsevier.

Geertsma, J. (1973). Land subsidence above compacting oil and gas reservoirs. J. Petrol. Technol., 25(6), 734-744.
https://doi.org/10.2118/3730-PA

Hall, H. (1953). Compressibility of reservoir rocks. J. Petrol Technol., 5(1), 17-19.
https://doi.org/10.2118/953309-G

Jaeger, J. & Cook, N. (1979). Fundamentals of rock mechanics. (3). London: Chapman & Hall.

Li, C., Chen, X. & Du, Z. (2004). A new relationship of rock compressibility with porosity. SPE Asia Pacific Oil and Gas Conference and Exhibition. SPE-88464-MS.
https://doi.org/10.2118/88464-MS

Mercado, C. & Mendoza, J. (2013). Aspectos operacionales, geológicos y geomecánicos del fenómeno de compactación y subsidencia durante la producción de hidrocarburos. Tesis de pregrado, Ingeniería de Petróleos, Universidad Industrial de Santander, Bucaramanga, Colombia, 230pp.

Quoc, T. (2007). Coupled fluid flow-geomechanics simulations applied to compaction and subsidence estimation in stress sensitive & heterogeneous reservoirs. Ph. D thesis, Australian School of Petroleum, University of Adelaide, South Australia, 198pp.

Smith, J. E. (1971). The dynamics of shale compaction and evolution of pore-fluid pressures. Math. Geol., 3(3), 239-263.
https://doi.org/10.1007/BF02045794
How to Cite
Mendoza Molina, J. F., Mercado Montes, C. A., & Calderón Carrillo, Z. H. (2015). New approach for compaction prediction in oil reservoirs. CT&F - Ciencia, Tecnología Y Futuro, 6(1), 5-16. https://doi.org/10.29047/01225383.23