Rock Type Connectivity Estimation Using Percolation Theory
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Complicated sedimentary processes control the spatial distribution of geological heterogeneities. This serves to make the nature of the fluid flow in the hydrocarbon reservoirs immensely complex. Proper modeling of these heterogeneities and evaluation of their connectivity are crucial and affects all aspects of fluid flow. Since the natural variability of heterogeneity occurs in a myriad of length scales, accurate modeling of the rock type connectivity requires a very fine scheme, which is computationally very expensive. Hence, this makes other alternative methods such as the percolation approach attractive and necessary. The percolation approach considers the hypothesis that a reservoir can be split into either permeable (sand/fracture) or impermeable rocks (shale/matrix). In this approach, the connectivity of the permeable fraction governs the flow. This method links the global properties of the system to the density of the permeable objects distributed randomly in the system. Moreover, this approach reduces many results to some simple master curves from which all-possible outcomes can be predicted by simple algebraic transformations. The current study contributes to extending the applicability of the methodology to anisotropic systems as well as using the complicated and more realistic sandbody shapes (for example, ellipsoids). This enables us to attain a better assessment of the connectivity and its associated uncertainty of the complicated rock types. Furthermore, to validate the approach, the Burgan reservoir dataset of the Norouz offshore oil field in the south of Iran was used. The findings are in conformity with the percolation approach predictions.
KeywordsPercolation theory Rock type Connectivity Ellipsoid sandbodies Anisotropy Validation
The authors would like to acknowledge useful conversations with Dr Tavakoli. In addition, we are grateful to the editor and reviewers who provided many useful suggestions.
- Chapra SC, Canale R (2002) Numerical methods for engineers: with software and programming applications. McGraw-Hill, New York Google Scholar
- Haldorsen HH, Brand PJ, Macdonald CJ (1988) Review of the stochastic nature of reservoirs. In: Edwards S, King PR (eds) Proceed math oil prod. Clarendon Press, Oxford Google Scholar
- Huerlimann A (2004) MDP report of Shell Company. Appendix seven of Soroosh & Nowrooz Burgan rock properties. Tehran, Iran Google Scholar
- Mutti E, Normark WR (1991) An integrated approach to the study of turbidite systems. In: Weimer P, Link MH (eds) Seismic facies and sedimentary processes of submarine fans and turbidite systems. Springer, New York, pp 75–106 Google Scholar
- Nurafza P, King PR, Masihi M (2006) Facies connectivity modelling: analysis and field study. In: Proceedings annual conference and exhibition of SPE Europec/EAGE, Vienna, Austria, SPE 100333 Google Scholar
- Sahimi M (1994) Applications of percolation theory. Taylor and Francis, London Google Scholar
- Stauffer D, Aharony A (1994) Introduction to percolation theory. Taylor & Francis, London Google Scholar