Reservoir flow numerical simulation method and system after heterogeneous fracturing

Abstract

The embodiment of the invention provides a reservoir flow numerical simulation method and system after heterogeneous fracturing. The method comprises the following steps: obtaining a discrete fracturenetwork after heterogeneous fracturing and a transformation area reservoir range; dividing the boundary of the discrete fracture network and the reservoir into a plurality of fracture micro-elementsand a plurality of boundary units; converting the flowing differential equation of the reservoir into a boundary integral equation of the corresponding reservoir, and solving to obtain a boundary element solution of the reservoir; coupling the discrete fracture flow equation and the reservoir boundary element solution to obtain a discrete fracture network-two-region flow coupling matrix; and performing flow numerical simulation on the reservoir according to the discrete fracture network-two-region flow coupling matrix. From the perspective of seepage mathematical model establishment, a fracturing fracture network formed by artificial fractures, induced fractures and natural fractures is extracted into a discrete fracture network-two-region heterogeneous conceptual model, and the discrete fracture network-two-region heterogeneous conceptual model can be used for simulating flow behaviors under different arbitrary reservoir two-region heterogeneous forms and arbitrary fracture network distribution combinations.

Description

technical field [0001] The present application relates to the technical field of underground fluid flow, in particular to a numerical simulation method for reservoir flow after heterogeneous fracturing. Background technique [0002] Fractures are an important geological feature in underground reservoirs. From the results of fracture extension and microseismic monitoring, artificial fractures usually appear as a network of fractures, while induced fractures are essentially derived from natural fractures. When the natural fractures in the reservoir are weakly developed When , the development of induced fractures is weak, almost negligible; when the development of natural fractures in the reservoir is strong, induced fractures usually occur on a large scale in the near-wellbore zone, and form stimulated zones of different shapes. According to the characteristics of different fractures, select the appropriate characterization methods, use the discrete fracture network method to ...

AI Technical Summary

Problems solved by technology

This type of method is convenient and quick to calculate, but it is only applicable to the case of crack rules

The numerical solution method discretizes the fracture into microelements, and the matrix space is not discrete, and couples and solves the fracture microelement flow equation and the matrix space flow equation through the continuity conditions of flow and pressure on the fracture microelement boundary surface. This kind of method can be faster and more accurate. Simulate the mass transfer process in a complex fracture network, but since the current numerical solution methods are all based on real-space source functions, the use of the superposition principle considering inter-fracture interference brings a huge amount of calculation

The numerical simulation method discretizes strata and fractures, which can simulate the seepage state of complex fracture networks in various actual situations, but for areas with strong fracture development, the number of grids increases significantly, and the calculation efficiency is low

Images