Experimental device for research on rock high temperature thermal rupture under stress effect

Abstract

The invention discloses an experimental device for research on rock high temperature thermal rupture under stress effect, the experimental device includes a heating system, a rock core holding system, a crack detection system and a temperature measurement system. The heating system is used for continuous heating of rock core to create high temperature conditions; the rock core holding system is used for applying horizontal stress to the periphery of the rock core for simulation of the formation confining pressure effect and meanwhile to play the role of fixing the rock core to prevent the occurrence of loosening; the crack detection system is used for amplifying and processing vibration wave signals sent from the inner part of the rock core and recording structure changes of the inner part of the rock core so as to determine the rock core fracture time and fracture position; and the temperature measurement system is used for recording the rock core rupture temperature. Aiming at the structure changes occurring in the inner part of the rock core at high temperature, real-time dynamic observation of the thermal rupture caused by rock heating can be realized. The experimental device has strong practicability, can be used for analysis description of the structure changes occurring in the inner part of the rock core during observation of vibration wave phenomenon, and an effective experimental method is provided for research on rock rupture during rock thermal exploitation process.

Description

technical field [0001] The invention relates to an experimental device in the field of petroleum development, in particular to an experimental device for producing cracks in rocks subjected to high-temperature steam during thermal recovery. Background technique [0002] In a high-temperature environment, due to the different thermal expansion coefficients of the various minerals that make up the rock, the rock will crack under the action of thermal stress. This phenomenon is called the thermal cracking of the rock. The research on thermal fracture of rocks has been developed along with the researches on storage of nuclear waste, oil extraction, and development and utilization of geothermal resources. For example, in the process of oil extraction, the thermal fracture characteristics of rocks can be used to induce rock fractures to achieve the purpose of improving reservoir permeability. At the same time, the viscosity of crude oil is reduced after heating, which helps to inc...

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Problems solved by technology

The uniaxial compressive creep test can reflect the influence of temperature and time on the deformation characteristics and strength characteristics of rocks, but because it only applies confining pressure in the uniaxial direction, it cannot simulate the entire process of real rocks being heated to generate cracks; The axial stress experiment can simulate the constitutive relationship of rock mass cracks and the transformation relationship between brittle and plastic deformation by applying confining pressure in the triaxial direction to the rock, but the distribution of cracks inside the rock is not appreciable; The technology can observe the mesoscopic deformation and strength characteristics of the rock under load in real time and dynamically, and reveal the influence of the stress level on the generation and propagation of cracks. However, the slicing process may destroy the micro-damage structure of the rock, and cannot quantitatively detect the cracks after the rock is broken. The distribution of rock micro-cracks and fractal characteristics can be observed through nuclear magnetic resonance technology. Low and expensive, the application is greatly limited

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