A Reservoir Numerical Simulation Method for Calculating the Flow of Multiple Intersecting Discrete Fractures

Abstract

The invention discloses a numerical reservoir simulation method for measuring the flowing situation of a plurality of intersected discrete cracks. The method comprises the steps that a reservoir is divided into a continuous medium and a discrete crack medium; in order to remove extremely small grids, when a reservoir grid is created, a discrete crack endpoint is deformed or is simplified to be a segment by neglecting the thickness, then a rock stratum face grid is established, and a three-dimensional reservoir grid is established; practically measured reservoir parameters of holes, leakage, saturation and the like are input into a simulator, then a real value instead of a grid display value is used as the width of each discrete crack, and accuracy of a measured and calculated result is not lowered by deformation processing; the volume of the intersecting area of the discrete cracks is neglected, and a flow formula of the discrete cracks in the intersecting area is established; the reservoir parameters are corrected by utilizing the history fitting method; then well yield and remaining oil gas distribution and reserves are measured and calculated. The numerical reservoir simulation method can solve the problems that the discrete crack value simulation technology is prone to interruption and failure and is long in consumed time for measurement and calculation, so that the technology can achieve measurement and calculation in the whole process of full three-dimensional reservoir development, and improves accuracy of the measured and calculated result.

Description

technical field [0001] The invention belongs to the technical field of oil reservoir numerical simulation, and relates to point element processing of discrete fracture intersecting areas to improve the accuracy of numerical simulation calculation of oil reservoir flow conditions and improve the oil reservoir development effect. Background technique [0002] Improving the development effect of the reservoir includes reducing the development cost of the reservoir and increasing the recovery factor of the reservoir. First of all, it is necessary to correctly understand the geological model, seepage law, remaining oil and gas distribution, production law and influencing factors of the reservoir; based on the correct understanding of reservoir geology, that is, the seepage law, a reasonable reservoir development plan can be obtained for scientific and rational development. Oilfields (including gas fields) provide the basis. Reservoir numerical simulation technology is the main t...

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Problems solved by technology

Example 1: During water flooding, the continuum method cannot correctly reflect the water conduction effect of large-scale fractures, and cannot correctly reflect the water cut law changes of oil wells. Because of inaccurate measurement and calculation, the distribution of oil and gas is not clear, and the understanding of seepage process is not clear. The developed development plan lacks pertinence, resulting in waste of investment and even deterioration of production status; Example 2: After the oil well is fractured, fractures will be formed. If the fractures are treated with a continuous medium, the production of the oil well calculated based on this will often appear very large. big error

Therefore, the traditional continuum method is not suitable for calculating the flow process of all reservoirs, and the numerical simulation of fractured reservoirs also needs to use the method of discrete fracture media to calculate the flow process of oil and gas

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