Unconventional double-medium reservoir volume fracturing numerical simulation and parameter optimization method

Abstract

The invention discloses an unconventional double-medium reservoir volume fracturing numerical simulation and parameter optimization method, which comprises the following steps of: developing a hydraulic fracture viscoelastic-plastic damage model based on explicit time integration by considering a friction effect between fractures on the basis of a double-medium pore elasticity theory; simulating random intersection and bifurcation of the hydraulic fractures meeting natural fractures by adopting a method of embedding zero-thickness fracture units into the inner boundaries of the computational model grids, and establishing a mathematical model of volume fracturing hydraulic fracture expansion of the unconventional double-medium reservoir; compiling a finite element program of unconventionalreservoir volume fracturing complex multi-crack fracturing and competitive expansion, and establishing a hydraulic fracturing finite element model for a casing-cement ring-cluster perforation-reservoir matrix with natural fractures; carrying out research on the crack initiation and expansion law of the complex crack in the near-wellbore zone in the cluster i, carrying out the research on the synchronous expansion law of the multi-cluster hydrodynamic main crack and optimizing the volume fracturing construction process. Simulation factors are comprehensive, and an oil and gas exploitation construction scheme is optimized.

Description

technical field [0001] The invention relates to the technical field of oil and natural gas development, in particular to a method for numerical simulation and parameter optimization of unconventional dual-media reservoir volume fracturing. Background technique [0002] For a long time, the contradiction between energy supply and demand in my country has been prominent, and the dependence on foreign oil and natural gas has been increasing year by year. In 2017, my country's dependence on foreign oil reached 67.4%, and natural gas reached 39.4%, which greatly exceeded the internationally recognized warning line and seriously threatened my country's energy security. According to a global survey conducted by the U.S. Energy Information Administration (EIA), my country's shale gas reserves are 36.1 trillion cubic meters, ranking first in the world. As a typical unconventional natural gas resource, my country's shale gas resources have great development potential. my country's sh...

AI Technical Summary

Problems solved by technology

However, these studies all assume that after multi-cluster perforation fracturing, a main fracture is formed at each perforation cluster, and the main fractures of each perforation cluster expand together. field and fracture morphology, few scholars have studied the expansion, propagation, intersection and bifurcation behavior of multiple fractures initiated from perforation holes in the perforation cluster in the near-wellbore zone

At the same time, unconventional dual-media reservoirs usually contain a large number of natural fractures, which are typical dual-media systems. However, in existing hydraulic fracture propagation models, unconventional dual-media reservoirs are generally treated as conventional single-media or even impermeable media. , which will affect the calculation accuracy of the fluid pressure distribution near the main fracture during the fracturing process, and then affect the fracture initiation and propagation behavior of the unconnected natural fractures after the hydraulic fracture meets the natural fracture and around the main fracture

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