Estimating pore‐space gas hydrate saturations from well log acoustic data

Lee, Myung W.; Waite, William F.

doi:10.1029/2008gc002081

Cited by 124 publications

(93 citation statements)

References 20 publications

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“…30% (maximum values of ca. 80%), which is equivalent to or higher than that at other hydrate-bearing sites, such as in permafrost in Canada (Mallik 5L-38), at Mount Elbert in Alaska, in the Gulf of Mexico, within the northern Cascadia margin (Lee & Waite 2008), and in the Nankai Trough offshore from the mouth of the Tenryu River (e.g. Tsuji et al 2004).…”

Section: Discussionmentioning

confidence: 99%

“…The relationship between gas hydrate and P-wave velocities can be modeled using a TPE (Leclaire et al 1994;Carcione & Tinivella 2000;Lee 2007) and by assuming that gas hydrate acts as a load-bearing component within sediments. We used a simplified TPE (Lee 2008) to calculate velocities for the gas hydrate-bearing sediments; details of the TPE used for gas hydrate-bearing sediments are given in Lee and Waite (2008) and Lee (2007. The Vp of gas hydrate-bearing sediments (Vp) was calculated as follows:…”

Section: Gas Hydrate Saturationmentioning

confidence: 99%

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Gas hydrate saturation at Site C0002, IODP Expeditions 314 and 315, in the Kumano Basin, Nankai trough

et al. 2014

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The degree of gas hydrate saturation at Integrated Ocean Drilling Program (IODP) Site C0002 in the Kumano Basin, Nankai Trough, was estimated from loggingwhile-drilling logs and core samples obtained during IODP Expeditions 314 and 315. Sediment porosity data necessary for the calculation of saturation were obtained from both core samples and density logs. Two forms of the Archie equation ('quick-look' and 'standard') were used to calculate gas hydrate saturation from two types of electrical resistivity log data (ring resistivity and bit resistivity), and a three-phase Biot-type equation was used to calculate gas hydrate saturation from P-wave velocity log data. The gas hydrate saturation baseline calculated from both resistivity logs ranges from 0% to 35%, and that calculated from the P-wave velocity log ranges from 0% to 30%. High levels of gas hydrate saturation (>60%) are present as spikes in the ring resistivity log and correspond to the presence of gas hydrate concentrations within sandy layers. At several depths, saturation values obtained from P-wave velocity data are lower than those obtained from bit resistivity data; this discrepancy is related to the presence of free gas at these depths. Previous research has suggested that gas from deep levels in the Kumano Basin has migrated up-dip towards the southern and seaward edge of the basin near Site C0002. The high saturation values and presence of free gas at site C0002 suggest that a large gas flux is flowing to the southern and seaward edge of the basin from a deeper and/or more landward part of the Kumano Basin, with the southern edge of the Kumano Basin (the location of site C0002) being the main area of fluid accumulation.

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Section: Discussionmentioning

confidence: 99%

Section: Gas Hydrate Saturationmentioning

confidence: 99%

Gas hydrate saturation at Site C0002, IODP Expeditions 314 and 315, in the Kumano Basin, Nankai trough

et al. 2014

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“…Other procedures are based on seismic data analysis, using velocity seismic models and/or amplitude variations versus offset analysis [23][24][25]. Moreover, some authors have suggested modelling elastic velocities versus gas hydrate concentrations using seismic velocities [26][27][28] or sonic log data [26,29] to obtain information about the hydrate occurrence.…”

Section: Introductionmentioning

confidence: 99%

Offshore Antarctic Peninsula Gas Hydrate Reservoir Characterization by Geophysical Data Analysis

et al. 2010

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A gas hydrate reservoir, identified by the presence of the bottom simulating reflector, is located offshore of the Antarctic Peninsula. The analysis of geophysical dataset acquired during three geophysical cruises allowed us to characterize this reservoir. 2D velocity fields were obtained by using the output of the pre-stack depth migration iteratively. Gas hydrate amount was estimated by seismic velocity, using the modified Biot-Geerstma-Smit theory. The total volume of gas hydrate estimated, in an area of about 600 km 2 , is in a range of 16 × 10 9 -20 × 10 9 m 3 . Assuming that 1 m 3 of gas hydrate corresponds to 140 m 3 of free gas in standard conditions, the reservoir could contain a total volume that ranges from 1.68 to 2.8 × 10 12 m 3 of free gas. The interpretation of the pre-stack depth migrated sections and the high resolution morpho-bathymetry image allowed us to define a structural model of the area. Two main fault systems, characterized by left transtensive and compressive movement, are recognized, which interact with a minor transtensive fault system. The regional geothermal gradient (about 37.5 °C/km), increasing close to a mud volcano likely due to fluid-upwelling, was estimated through the depth of the bottom simulating reflector by seismic data.

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“…Pore-filling hydrate reduces the permeability more significantly than mineralcoating hydrate [57]. Based on the limited data available for gas free, hydrate-bearing systems [58], pore-filling hydrate models provide the best estimates of permeability [59,60].…”

Section: Permeabilitymentioning

confidence: 99%

Advances in Study of Mechanical Properties of Gas Hydrate-Bearing Sediments

鲁晓兵

张旭辉²,

王淑云³

2013

TOOEJ

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Gas hydrate (GH) is defined as the crystalline solid, or clathrate hydrate, which are formed by some kinds of low mass molecular gases, such as methane, carbon dioxide, and hydronitrogen, with water at relatively high pressure and low temperature conditions. Gas hydrate-bearing sediments (HBS) are some sand, clay and mixed sediment containing gas hydrates. Advances in the study on the mechanical properties of HBS are summarized mainly in aspects of the laboratory test, in-situ investigation, and theoretical model. Firstly, the main factors are discussed including the structure of GH, formation method and matrix characteristics of HBS; Secondly, progress on the laboratory tests and results are discussed, which mainly includes the tri-axial tests with the natural and synthesized HBS samples, the acoustic tests for measuring the elastic coefficients, the tests for investigating the effects of main factors such as the gas and water contents and soil types on the strength of HBS. Thirdly, for in-situ investigations, including the geophysical surveying, in-situ tests (such as downhole tests) and results are summarized; Fourthly, several theoretical models for estimating the mechanical properties of HBS are introduced; At last, the emphases and the tendency in the future study on the mechanical properties of HBS are discussed.

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Estimating pore‐space gas hydrate saturations from well log acoustic data

Cited by 124 publications

References 20 publications

Gas hydrate saturation at Site C0002, IODP Expeditions 314 and 315, in the Kumano Basin, Nankai trough

Gas hydrate saturation at Site C0002, IODP Expeditions 314 and 315, in the Kumano Basin, Nankai trough

Offshore Antarctic Peninsula Gas Hydrate Reservoir Characterization by Geophysical Data Analysis

Advances in Study of Mechanical Properties of Gas Hydrate-Bearing Sediments

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