A confining pressure hydraulic fracturing experimental device and its application method

Abstract

The invention discloses a confining pressure hydraulic fracturing experiment device and a method for using the same. It relates to a sample, including a confining pressure device and a collection device for collecting event-related information when an event of the sample occurs; the confining pressure device includes A pressure bearing shaft, an end cover, a cavity forming a sealed space with the end cover, an exhaust valve, a first, a second, a third water injection valve, a vacuum pump, a pressure transmitter, a water pump, and a water injection pipe; the collection device includes Acoustic emission sensors, sound receivers, stress strain gauges, stress strain gauges. The present invention overcomes the deficiency that the prior art cannot locate cracks, and avoids the artificial influence of the traditional method based on continuous mechanics; by using the principle of acoustic emission, stress and strain effects, the parameters of the fracturing process can be obtained more realistically, especially the location of the fracture can be located , record the series of characteristics such as the waveform and frequency released by the fracture, and simulate the changes of relevant parameters and fracture laws of hydraulic fracturing of different coal and rock samples under different confining pressure conditions.

Description

technical field [0001] The invention relates to a confining pressure hydraulic fracturing experimental device and a using method thereof. Background technique [0002] Hydraulic fracturing technology was first applied in petroleum engineering to increase the production of poor oil wells, and has gradually become one of the most reliable methods for measuring the in-situ stress of deep formations. It has also been used in the development of geothermal resources and the storage of nuclear waste. Therefore, hydraulic fracturing technology has important industrial value and economic benefits. [0003] The fracture pressure in hydraulic fracturing is the fluid pressure at the bottom of the well when the formation produces hydraulic fractures or opens the original fractures, and the fracture pressure gradient refers to the ratio of the fracture pressure to the depth, which is called the fracture pressure gradient. The formation fracture pressure is determined by the downhole pipe...

AI Technical Summary

Problems solved by technology

However, there is often a large gap between the predicted fracture extension pressure and the measured value. This is because the technical solution cannot accurately locate the fracture, and cannot analyze the stress and strain effects. Some assumptions of the design model are not necessarily In line with the actual formation conditions, so the experimental device needs to be further improved

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