Characterization and reconstruction of meso-structure of gas-bearing soils at different storage pressures

Guo Zhenqi; Liu Tao; Wu Chen; Su Xiuting; Li Sanpeng

doi:10.12284/hyxb2021154

Volume 43 Issue 11

Dec. 2021

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Guo Zhenqi，Liu Tao，Wu Chen, et al. Characterization and reconstruction of meso-structure of gas-bearing soils at different storage pressures[J]. Haiyang Xuebao，2021, 43(11)：96–104 doi: 10.12284/hyxb2021154

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Characterization and reconstruction of meso-structure of gas-bearing soils at different storage pressures

doi: 10.12284/hyxb2021154

Guo Zhenqi^1
,,
Liu Tao^{1, 2, 3
,
,},
Wu Chen¹,
Su Xiuting^{1, 4},
Li Sanpeng¹

1.
College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China
2.
Laboratory for Marine Geology, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao 266237, China
3.
Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, Qingdao 266100, China
4.
SGIDI Engineering Consulting (Group) Co., Ltd Qingdao Branch, Qingdao 266199, China

Received Date: 2020-11-04
Rev Recd Date: 2021-01-14

Available Online: 2021-08-11

Publish Date: 2021-12-31

Abstract

Abstract

The storage pressure and reconstruction of the mesostructure of gas-bearing sediments are key factors in the study of shallow gas geohazards. Using an industrial CT scanning test system, vertical rotational (SR) scanning is used, with the position of the microfocus X-ray source fixed and the sample rotated at a constant speed of 360° along the XY plane, with a set rotation step of 0.3° per second, the gas-bearing samples in the reactor are pressurized to 2 MPa, 4 MPa, and 6 MPa, taking into account the best resolution of the sample imaging, the best detection range and other. The results show that the slices and reconstructed images obtained from the CT scan have good experimental results; the greyscale values of small bubbles increase when pressurized to 2 MPa; the overall greyscale values of gas increase significantly when pressurized to 6 MPa; the number of bubbles decrease with increasing bubble radius during the pressurization process; the pressurization process lead to local changes in the solid-liquid-gas phase, which show that the volume of pore gas and pore water changes more than that of the soil skeleton. The overall change is greater than that of the soil skeleton, and the microscopic local location will have a greater rise or decrease. When the gas content at different locations rises and dominates, it will drive the reduction of pore water and the movement of the soil skeleton.
- gas bearing sediments,
- gas reservoir pressure,
- microstructure,
- CT scan

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References(19)

References

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