Supercritical carbon dioxide rock core fracturing experiment method under saturated pore pressure

Abstract

The invention provides a supercritical carbon dioxide rock core fracturing experiment method under a saturated pore pressure. The supercritical carbon dioxide rock core fracturing experiment method comprises the following steps: 1, processing a rock material to form a test piece having a predetermined dimension, and placing the test piece in a sealed gum cover; 2, sleeving a clamping sleeve outside a left plug head, the sealed gum cover and a right plug head; 3, fully filling an annular chamber with hydraulic oil through liquid injecting pores in the sidewall of the clamping sleeve, and keeping the temperature of the oil at a preset temperature value; 4, moving the right plug head to the test piece to gradually press the test piece in order to apply an axial pressure to the test piece, and injecting nitrogen to the filling channel of the right plug head to make the nitrogen enter the test piece; 5, injecting a supercritical carbon dioxide fluid to the filling channel of the left plug head, and allowing the supercritical carbon dioxide fluid to enter the test piece from a simulated shaft in order to fracture the test piece; and 6, taking out the test piece after the fracturing ends, and observing a crack formed in the test piece.

Description

technical field [0001] The invention belongs to the fields of oil and gas reservoir development and geotechnical engineering, and in particular relates to a supercritical carbon dioxide core fracturing experiment method under saturated pore pressure. Background technique [0002] In oil and gas extraction operations, due to the low porosity and low permeability characteristics of shale gas reservoirs, reservoir fracturing and permeability enhancement must be carried out to develop shale gas. At present, the United States, which successfully exploits shale gas, mainly adopts hydraulic fracturing technology, but this technology consumes a large amount of water resources and seriously pollutes groundwater; at the same time, the clay content of shale in China is generally high, and shale is easy to expand when exposed to water. It will affect the effect of reservoir reconstruction. In addition, China's currently proven shale gas reserves are mostly distributed in basins and mou...

AI Technical Summary

Problems solved by technology

However, due to the lack of theoretical and experimental research on supercritical carbon dioxide fracturing shale, especially the lack of corresponding experimental devices to simulate the changes in reservoir permeability, stress and strain during supercritical carbon dioxide fracturing shale Law, which limits the scope of application of carbon dioxide in shale gas exploitation

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