Super-critical carbon dioxide fractured shale damage positioning monitoring device and method

Abstract

The invention discloses a super-critical carbon dioxide fractured shale damage positioning monitoring device and method, and belongs to the technical field of shale gas exploitation. The device comprises a true tri-axial loading system, an acoustic emission monitoring system, a super-critical CO2 fracturing system, a temperature control system and a deformation testing system, wherein the true tri-axial loading system is used for loading different stresses for shale test pieces; the acoustic emission monitoring system is used for monitoring the acoustic emission characteristic of super-critical CO2 fractured shale test piece crack propagation under a true tri-axial condition, planar and three-dimensional damage positioning and a cracking position and an evolution process of a crack; the super-critical CO2 fracturing system is used for injecting CO2 in a super-critical state into the shale test piece. According to the device, the fracture mechanism of large-sized shale under the super-critical CO2 effect under the true tri-axial stress condition can be physically simulated, the acoustic emission characteristic of the super-critical CO2 fractured shale test piece crack propagation, planar and three-dimensional damage positioning and the cracking position and the evolution process of the crack are analyzed, and a theoretical foundation is laid for research of the super-critical CO2 high-efficiency shale gas exploitation.

Description

technical field [0001] The invention belongs to the technical field of shale gas exploitation, and relates to a supercritical carbon dioxide fracturing shale damage location monitoring device and method. Background technique [0002] With the sustained and rapid development of the national economy, my country's demand for energy is increasing day by day, and the situation of shortage of domestic energy resources is becoming more and more serious. In 2013, my country's coal output was 3.7 billion tons, and the net import volume reached 320 million tons. The natural gas output was 121 billion cubic meters, and the import volume was 53.4 billion cubic meters. The oil output is 210 million tons, the import volume is 282 million tons, and the degree of foreign dependence reaches 60%. In order to solve the tense state of energy, the country will focus on the development of unconventional natural gas in the "Twelfth Five-Year Plan" energy plan. [0003] At present, the United St...

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Problems solved by technology

At present, there are very few simulation devices developed in this area at home and abroad. Therefore, there is an urgent need for an experimental device and method that can realize the above functions.

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