Abstract
Gas-charged marine sediments were sampled using a pressure core barrel and a new technique involving standard wireline sampling procedures. Pressure core barrel sampling provides sediments atin situ pressures with no degassing. Analysis of gas content, geotechnical properties and microfabric were performed for samples atin situ pressures and compared with degassed results. Methane concentrations ranged from 3,450 to 137,140 ppm for pressurized samples. Microfabric analyses reveal highly nonoriented clay particles and grains in degassed samples. Degassing of these methane-rich sediments increases porosities and compression indices, while reducing undrained shear strengths and computed preconsolidation pressures.
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Johns, M.W., Taylor, E. & Bryant, W.R. Geotechnical sampling and testing of gas-charged marine sediments atin situ pressures. Geo-Marine Letters 2, 231–236 (1982). https://doi.org/10.1007/BF02462769
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DOI: https://doi.org/10.1007/BF02462769