Application limits for deterministic geological-and-reservoir models

Authors: R.S. Khisamov (Tatneft ОАО RF, Almetyevsk), A.V. Nasybullin, A.V. Lifantyev (TatNIPIneft, RF, Bugulma)

Key words: geological-and-reservoir model, well logging, oil recovery efficiency, fine grid, reservoir heterogeneity.

According to reservoir engineering regulations, design projects should be based on permanently upd ated geological-and-reservoir models. This paper analyzes model dataware based on well logging and offse t well drilling.

This paper discusses the effect of grid size on reservoir properties heterogeneity using three methods:

- qualitative evaluation from probability density diagram

- quantitative estimation of the system entropy

- quantitative estimation from variation coefficient

It has been shown that grid refinement doesn’t result in simulated reservoir heterogeneity growth. When input data are entered into the grid, simulated heterogeneity decrease rate doesn’t change with increase of actual reservoir heterogeneity. Permeability distribution is fractal and hyperbolic. Fractal distribution can not be simulated by deterministic methods. Stochastic models shall be used to take into account the effect of well spacing on oil recovery efficiency.
References
1. Recommended practice on volumetric estimation of petroleum reserves,
Edited by Petersilye V.I., Poroskun V.I., Yatsenko G.G., Moscow - Tver: VNIGNI, NPTs Tvergeophisika, 2003.
2. Mirzadjanzade A.Kh., Khasanov M.M., Bakhtizin R.N., Simulation of petroleum
production processes. Non-linearity, non-equilibrium, uncertainties,
Moscow-Izhevsk: Institute of computer-assisted surveys, 2004.
3. Aziz K., Ten golden rules for simulation engineers, JPT, 1989, V. 41, no. 11,
pp. 1157.
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