Device and method for detecting mechanical parameters of hydrate-containing sediments based on X-CT

Abstract

The invention provides a device and a method for detecting mechanical parameters of hydrate-containing sediments based on X-CT. The device comprises a reaction kettle, a shear loading unit, a back pressure control unit, an unloading pressure loading unit and a strain measurement unit, wherein the reaction kettle body is a beryllium or carbon fiber pressure-resistant pipe, and the two end are sealed with end covers; the outer side of the lower end cover is connected with an axial pressure loading counter-force mechanism; an upper sample adjusting cushion block, a sediment sample, a lower sampleadjusting cushion block and an axial pressure loading piston are arranged in the reaction kettle from top to bottom. According to the device and the method, high-pressure conditions required for synthesizing the methane hydrate are met, and the axial temperature of the sample can be precisely controlled, so that the sample is uniformly distributed; the sample preparation efficiency can be improved through the rapid temperature control, the sample size can be adjusted, and the purpose of controlling height-diameter ratios of the different samples is achieved; and the synchronous detection of astress-strain curve of the sediments containing the natural gas hydrate and the internal destructive microstructures of the sediments can be achieved, and the constant strain shearing and the constant stress creep tests can be realized.

Description

technical field [0001] The invention relates to the field of basic physical property evaluation of natural gas hydrate reservoirs, in particular to a device and method for analyzing microscopic damage zones and macroscopic stress-strain curves of hydrate-containing sediments based on the combination of micro-nano CT scanning and triaxial experiments. Background technique [0002] Studying the dynamic response characteristics of reservoir mechanical parameters in the process of hydrate mining is the basis for revealing the critical conditions for the occurrence of engineering geological risks related to hydrate mining, evolution rules and their impact on hydrate mining. Conventional mechanical parameter tests mainly use sediment failure under "short-term" loads as the basis for evaluating the mechanical properties of hydrate-containing sediment systems, but lack of time-sensitive behavior of slow deformation (ie, creep) of reservoirs under long-term mining conditions. researc...

AI Technical Summary

Problems solved by technology

[0006] In view of the defects existing in the prior art that cannot meet the high pressure required for the synthesis of methane hydrate, uneven temperature control methods, and insufficient temperature control efficiency, which affect the measurement accuracy, the present invention proposes a method for realizing hydrate deposition in a high-pressure environment. The device for X-CT scanning of matter and the simultaneous accurate measurement of macro and micro of sediment sample deformation process is realized by the following technical scheme:

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