An experimental study on microscopic characteristics of gas-bearing sediments under different gas reservoir pressures

• Published in: Acta oceanologica Sinica Vol. 40; no. 10; pp. 144 - 151
• Main Authors: Guo, Zhenqi, Liu, Tao, Guo, Lei, Su, Xiuting, Zhang, Yan, Li, Sanpeng
• Format: Journal Article
• Language: English
• Published: Beijing The Chinese Society of Oceanography 01.10.2021; Springer Nature B.V; College of Environmental Science and Engineering,Ocean University of China,Qingdao 266100,China%Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering,Ocean University of China,Qingdao 266100,China; College of Environmental Science and Engineering,Ocean University of China,Qingdao 266100,China; Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering,Ocean University of China,Qingdao 266100,China; Laboratory for Marine Geology,Pilot National Laboratory for Marine Science and Technology(Qingdao),Qingdao 266237,China%Institute of Marine Science and Technology,Shandong University,Qingdao 266237,China%Laboratory for Marine Geology,Pilot National Laboratory for Marine Science and Technology(Qingdao),Qingdao 266237,China%College of Marine Geosciences,Ocean University of China,Qingdao 266100,China%Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering,Ocean University of China,Qingdao 266100,China
• Subjects: Bubbles; Climatology; Computed tomography; Earth and Environmental Science; Earth Sciences; Ecology; Engineering Fluid Dynamics; Environmental Chemistry; Gases; Image processing; Marine & Freshwater Sciences; Oceanography; Physical characteristics; Pore water; Pressure; Reservoirs; Sediment; Sediment samplers; Sediment samples; Sediments; Soil; Soil strength; Soil water movement; Soils; gas content; CT scanning; number and volume of bubbles; seabed sediments; micro characteristics; gas reservoir pressure
• ISSN: 0253-505X; 1869-1099
• DOI: 10.1007/s13131-021-1834-y

Gas-bearing sediments are widely distributed in five continents all over the world. Most of the gases exist in the soil skeleton in the form of discrete large bubbles. The existence of gas-phase may increase or decrease the strength of the soil skeleton. So far, bubbles’ structural morphology and evolution characteristics in soil skeleton lack research, and the influence of different gas reservoir pressures on bubbles are still unclear. The micro characteristics of bubbles in the same sediment sample were studied using an industrial CT scanning test system to solve these problems. Using the image processing software, the micro variation characteristics of gas-bearing sediments in gas reservoir pressure change are obtained. The results show that the number and volume of bubbles in different equivalent radius ranges will change regularly under different gas reservoir pressure. With the increase of gas reservoir pressure, the number and volume of tiny bubbles decrease. In contrast, the number and volume of large bubbles increase, and the gas content in different positions increases and occupies a dominant position, driving the reduction of pore water and soil skeleton movement.