An experimental device for testing rock fracture toughness under pore pressure conditions

Abstract

The invention relates to an experimental device for testing fracture toughness of rocks under a pore pressure condition. The experimental device comprises a testing machine, a confining pressure cavity and a clamping clamp. The testing machine comprises a testing machine rigid frame, a rigid frame pressing head, a trolley, a sliding rail, a hydraulic shaft and a hydraulic cylinder; the confining pressure cavity comprises a confining pressure barrel pressing head, a confining pressure barrel, a confining pressure barrel base and a positioning rod; the clamping clamp comprises a clamping base, a stand column, a supporting plate, a supporting roller, a pore pressure end socket, a compaction part, an upper cover plate, a clamp pressing head, an upper ring, a fixed bolt, a probe and a lower plate. The experimental device is simple in structure, convenient to operate and high in practicability, can be used for carrying out a fracture toughness test on rock materials and artificial materials under confining pressure-containing, high-temperature and pore pressure-containing conditions; an obtained result is more accurate, and accurate fracture toughness parameters are provided for calculation of hydraulic fracture models of oilfields and research institutes.

Description

technical field [0001] The invention belongs to the field of petroleum engineering rock mechanics, in particular to an experimental device for testing rock fracture toughness under pore pressure conditions. Background technique [0002] my country's low-permeability oil and gas fields are very rich in resources. Among my country's proven oil geological reserves in recent years, low-permeability reserves account for 60% to 70%. It can be seen that low-permeability oil fields or extra (ultra) low-permeability oil fields will be a considerable period in the future. The main resource base for increasing domestic reserves and production. Low-permeability reservoirs have low porosity, low permeability, strong heterogeneity, low reserve abundance, and are vulnerable to damage. Most oil and gas wells must implement fracturing stimulation measures before they can see production. Hydraulic fracturing technology has become an important measure for the reconstruction of low-permeability...

AI Technical Summary

Problems solved by technology

At present, the fracture toughness research and testing of rock materials do not consider the influence of pore pressure, and the fracture toughness test results of rock materials cannot reflect the real situation of the formation

In addition, regardless of the effect of pore pressure inside the rock, the obtained fracture toughness test results will not be able to obtain accurate results when used in model calculations

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