Fractured reservoir multi-scale fracture simulation method and computer readable storage medium

Abstract

The invention provides a fractured reservoir multi-scale fracture simulation method and a computer readable storage medium. The method comprises the steps that corner point grid model data, matrix attribute model data, fracture network model data and fracture attribute model data of a matrix are obtained; classifying and dividing the fracture network model into primary fractures and secondary fractures; constructing an unstructured basic grid based on the angular point grid model and the primary crack; utilizing a matrix attribute model and a crack attribute model to carry out attribute mapping on the unstructured basic grid; the matrix attribute of the mapped unstructured basic grid is corrected; and calculating the conductivity of the non-structured basic grid after attribute correction to obtain a non-structured hybrid grid model. By means of the simulation method, polarity discretization processing can be conducted on main-level cracks, flow characteristics of the cracks can be accurately captured, the precision of numerical simulation is improved, equivalence and coarsening methods are adopted for small and medium-scale cracks, and the efficiency of numerical simulation is greatly improved.

Description

technical field [0001] The present invention relates to the field of numerical simulation of oil reservoirs, and more specifically, relates to a method for simulating multi-scale fractures in fractured oil reservoirs and a computer-readable storage medium. Background technique [0002] Fractured reservoirs are a widely existing type of reservoirs. According to incomplete statistics, fractured reservoirs account for more than 28% of the proven geological reserves (Yuan Shiyi, Song Xinmin, Ran Qiquan. Fractured Reservoir Development Technology , Petroleum Industry Press, 2004). Usually, there are fractures with different sizes and properties in the reservoir. For the characteristics of fractures, the existing dual-media model (Warren, J.E. ) and discrete fracture model (Karimi-Fard, M., L.J.Durlofsky and K.Aziz. An efficient discrete-fracture model applicable for general-purpose reservoir simulators. SPE Journal, 2004, 9(2): 227-236) to Describe the cracks and provide models...

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Problems solved by technology

[0005] (2) Some fractures, such as fracturing secondary fractures and small-scale natural fracture networks, are usually small in size and weak in conductivity, and are distributed in a network-like staggered distribution, which is suitable for simulation by the dual-media model. If the discrete fracture model is used , will cause too many grids and the calculation speed is too slow (Sarma, P. and K. Aziz. New transfer functions for simulation of naturally fractured reservoirs with dual porosity models. SPEA annual Technical Conference and Exhibition, Society of Petroleum Engineers, 2004 )

Although there have been many improvements in the calculation methods of dual-media model parameters in recent years, such as the use of flow-based upscaling methods to calculate the permeability and channeling coefficient of fractured media grids, no matter which method is used, there are inevitably dual-media models. Limitations of the model (Kazemi, H., L.S. Merrill Jr, K.L. Porterfield and P.R. Zeman. Numerical simulation of water-oil flow innaturally fractured reservoirs. Society of Petroleum Engineers Journal, 1976, 16(6): 317-326)

[0007] To sum up, since fractured reservoirs usually have fractures of different origins, scales and distribution rules, the above two models cannot meet the requirements of accuracy and efficiency at the same time. Therefore, it is necessary to develop a model for multi-scale fractured reservoirs. New modeling and numerical simulation technology to solve the contradiction between fine modeling and high-efficiency numerical modeling of multi-scale fractured reservoirs

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