METHOD FOR MEASURING STRESS FIELD VARIATIONS DURING CO₂ FRACTURING PROCESS

摘要

A method for measuring stress field variations during a CO₂ fracturing process. The method employs CT scan, digital reconstruction, 3D printing, CO₂ fracturing experiments, stress freezing and photoelasticity measuring techniques, not only allows the transparent display of the spatial distribution and the form of extension of internal cracks of a three-dimensional physical model when fractured, but also acquires a three-dimensional stress phase diagram of the interior of the model during a fracture crack extension process, thus implementing the transparent display and quantitative expression of a three-dimensional stress field and an evolutionary rhythm thereof in a solid CO₂ fracturing process; and, at the same time, utilizes multiple identical transparent three-dimensional physical models to implement the display and expression, thus ensuring the accuracy and reliability of a measurement result, and solving the problem of low calculation precision and difficulty in ensuring accuracy and reliability found in an existing numerical simulation method.