Preset fracture hydraulic fatigue fracturing design method

Abstract

The invention discloses a preset fracture hydraulic fatigue fracturing design method which comprises the following steps of manufacturing a rock-like material standard sample, and performing a mechanical parameter test by utilizing the sample to obtain the mechanical parameters of a rock-like material; making a sample containing a through fracture, and performing a periodic cyclic load tension andcompression failure test by using the sample to obtain a stress-strain curve, a strain frequency curve and the material parameters in a Paris formula; utilizing a finite element software to establisha rock-like material finite element model, presetting fractures and fracture sizes in the finite element model, and substituting the test results into the finite element model; loading in a circulating pressure form, obtaining the fracture propagation of the rock-like material, and determining the combination form of the amplitude and the frequency parameter of the optimal circulating water pressure load.

Description

technical field [0001] The disclosure belongs to the technical field of hydraulic fracturing with preset fractures in rock and soil, and in particular relates to a design method for hydraulic fatigue fracturing with preset fractures. Background technique [0002] Hydraulic fracturing refers to a physical phenomenon that causes cracks in rock and soil mass or expands cracks under the action of water pressure. The method of hydraulic fracturing is widely used in various fields, such as pressure tunnel analysis, shale gas extraction, coal field mining, and ground stress measurement. In the field of oil and gas exploitation, my country is rich in shale gas resources, with a total reserve of about 134.42 trillion cubic meters (recoverable reserves of about 25.08 trillion cubic meters). However, due to the low porosity and permeability of shale reservoirs (general porosity If the permeability is lower than 10%, and the permeability is lower than 1mD), the formation seepage conditi...

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Problems solved by technology

[0005] However, at present, the construction parameters of rock fatigue failure under the action of circulating water pressure are still in the stage of empirical selection. In construction, there is a lack of corresponding theoretical guidance and construction design methods, and there is no theoretical basis for the impact on amplitude and frequency. In terms of numerical simulation , the lack of corresponding models for simulation evaluation

It is difficult to evaluate the effect of application in different rock formations