Method for improving oil reservoir exploitation effect by utilizing discrete fracture endpoint deformation numerical simulation

Abstract

The invention discloses a method for improving an oil reservoir exploitation effect by utilizing discrete fracture endpoint deformation numerical simulation. The method comprises the following steps of dividing an oil reservoir storage body into a continuous medium and a discrete medium according to a characteristic scale; deforming the end part of a discrete fracture from a square shape into a pointed shape to eliminate tiny grids, establishing rock stratum surface grids, and establishing three-dimensional oil reservoir grids; inputting measured oil reservoir parameters such as porosity, permeability and water saturation into a simulator, wherein a real value rather than a grid display value is used for the width of the discrete fracture; correcting the oil reservoir parameters by using a history matching method; and measuring and calculating the well productivity, residual oil and gas reserves and the distribution positions of residual oil and gas, and making a subsequent oil reservoir exploitation plan. According to the method, a discrete fracture numerical simulator can be prevented from measurement and calculation interruption and failures, the whole links of oil reservoir exploitation can be actually measured and calculated to improve the measurement and calculation accuracy of the well productivity and the residual oil and gas distribution of an oil reservoir, and a more effective development plan can be made to improve the oil reservoir exploitation effect.

Description

technical field [0001] The invention belongs to the technical field of numerical simulation of oil reservoirs, and relates to a method for improving the development effect of oil reservoirs by utilizing numerical modeling of discrete fracture end point deformation. Background technique [0002] Improving the development effect of the reservoir includes reducing the development cost of the reservoir and increasing the recovery rate of the reservoir. This first requires a correct understanding of the geological model, seepage law, remaining oil and gas distribution, production law and influencing factors of the reservoir; based on the correct Reservoir geology, that is, the understanding of seepage laws, researches reasonable reservoir development plans, and provides a basis for scientific and rational development of oil fields (including gas fields). Reservoirs are buried deep underground. Reservoir numerical simulation technology is the main method for calculating the seepag...

AI Technical Summary

Problems solved by technology

The key reasons hindering the development and application of the reservoir numerical simulation technology of the discrete fracture method are: (1) trying to treat all the fractures as discrete fractures, including micro-fractures, the resulting grids are too large to exceed the existing It has the processing power of a computer, and the relevant discrete fracture parameters are difficult to measure and obtain; (2) Compared with the continuum grid, the pore body of the discrete fracture grid is extremely small and the seepage capacity is too strong, which easily leads to inaccuracies in the calculation process. Convergence, unstable results, and too long calculation time; (3) Due to discrete fractures, the geometry of the reservoir is complicated, and the grid division is difficult

[0004] The calculation results of the continuum method and the discrete medium method will show great differences under certain conditions. For example, in the case of water flooding, the continuum method cannot correctly reflect the water conduction of large-scale fractures, and cannot correctly reflect the oil well. Changes in the law of water cut, due to inaccurate calculations, lead to unclear distribution of oil and gas, unclear understanding of seepage process, lack of pertinence in the development plan formulated, resulting in waste of investment and even deterioration of production conditions

Therefore, the traditional continuum method is not suitable for calculating the flow process of all oil reservoirs. 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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