Multi-scale true-triaxial horizontal well hydrofracturing pressure bearing cylinder and using method

Abstract

The invention belongs to the researching field of oil and gas reservoir exploitation techniques, and particularly relates to a multi-scale true-triaxial horizontal well hydrofracturing pressure bearing cylinder and a using method. The device is composed of a pressure bearing cylinder body, a telescopic pulling rod and a pulley base; the pressure bearing cylinder body is connected with the pulley base through a clamping groove, and the telescopic pulling rod is connected with the pulley base through a bolt; a passage hole is formed in the side wall of the pressure bearing cylinder body and used for penetrating out of a horizontal wellbore pre-buried in a testing rock sample, and the horizontal wellbore is connected with a hydrofacturing control system through a fracturing pipe; and steel pressure bearing plates are arranged on the three side free surfaces of the testing rock sample and make close contact with a confining pressure loading system. According to the multi-scale true-triaxial horizontal well hydrofracturing pressure bearing cylinder, manufacturing and operation is easy, the occupied area is small, measuring precision is high, the three-dimensional stress requirement is met, indoor simulation researching can be effectively conducted aiming at horizontal well hydrofracturing of rock reservoirs with different structures, the multi-scale true-triaxial horizontal well hydrofracturing pressure bearing cylinder is especially beneficial for researching influences of reservoir structures and rock mechanical properties on extension rules of cracks in the hydrpfracturing process of a multi-scale rock sample horizontal well, and a theoretical basis is provided for technique design and scheme optimization of hydrofracturing of normal or abnormal densified oil and gas reservoirs.

Description

technical field [0001] The invention belongs to the technical research field of oil and gas reservoir exploitation, and in particular relates to a multi-scale true triaxial horizontal well hydraulic fracturing pressure-bearing cylinder and a use method. Background technique [0002] Unconventional oil and gas reservoirs such as coalbed methane, shale gas, and tight oil and gas are widely distributed on land in China. However, these oil and gas reservoirs have extremely low porosity and permeability, and commercial exploitation requires large-scale hydraulic fracturing. In the process of hydraulic fracturing, the formation of a fracture network in which natural fractures (sedimentary bedding) and artificial fractures are interlaced is the key to increasing initial production and ultimate recovery. Research institutes at home and abroad are also actively seeking to establish the correlation between the microstructure and the mechanical properties of macroscopic fractures, and ...

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Problems solved by technology

[0006] The purpose of the present invention is to provide a pressure-bearing cylinder capable of performing horizontal well hydraulic fracturing simulation tests on rock samples of different structures and sizes under the condition of true triaxial stress and its use method, so as to solve the problem of hydraulic fracturing of multi-scale samples in horizontal wells. Research issues on crack propagation path, extension change mode and law

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