Rees, Emily V. L. et al. (2011): The structure of methane gas hydrate bearing sediments from the Krishna-Godavari Basin as seen from Micro-CT scanning

Leg/Site/Hole:
ODP 204
Identifier:
2012-076276
georefid

10.1016/j.marpetgeo.2011.03.015
doi

Creator:
Rees, Emily V. L.
Southampton University, School of Civil Engineering and Environment, Southampton, United Kingdom
author

Priest, Jeffery A.
author

Clayton, Chris R. I.
author

Identification:
The structure of methane gas hydrate bearing sediments from the Krishna-Godavari Basin as seen from Micro-CT scanning
2011
Marine and Petroleum Geology
Elsevier, Oxford, United Kingdom
28
7
1283-1293
The Indian National Gas Hydrate Program (NGHP) Expedition 1, of 2006, cored through several methane gas hydrate deposits on the continental shelf around the coast of India. The pressure coring techniques utilized during the expedition (HYACINTH and PCS) enabled recovery of gas hydrate bearing, fine-grained, sediment cores to the surface. After initial characterization core sections were rapidly depressurized and submerged in liquid nitrogen, preserving the structure and form of the hydrate within the host sediment. Once on shore, high resolution X-ray CT scanning was employed to obtain detailed three-dimensional images of the internal structure of the gas hydrate. Using a resolution of 80 mu m the detailed structure of the hydrate veins present in each core could be observed, and allowed for an in depth analysis of orientation, width and persistence of each vein. Hydrate saturation estimates could also be made and saturations of 20-30% were found to be the average across the core section with some portions showing highs of almost 60% saturation. The majority of hydrate veins in each core section were found to be orientated between 50 and 80 degrees to the horizontal. Analysis of the strikes of the veins suggested a slight preferential orientation in individual sample sections, although correlation between individual sections was not possible due to the initial orientation of the sections being lost during the sampling stage. The preferred vein orientation within sample sections coupled with several geometric features identified in individual veins, suggest that hydraulic fracturing by upward advecting pore fluids is the main formation mechanism for the veined hydrate deposits in the K-G Basin. Abstract Copyright (2011) Elsevier, B.V.
English
Serial
Coverage:Geographic coordinates:
North:44.3500
West:-125.0900East: 84.0000
South:15.0000

Economic geology, geology of energy sources; Applied geophysics; aliphatic hydrocarbons; alkanes; Asia; Bay of Bengal; East Pacific; gas hydrates; geometry; geophysical methods; hydrocarbons; imagery; India; Indian Ocean; Indian Peninsula; Krishna-Godavari Basin; Leg 204; methane; natural gas; naturally fractured reservoirs; North Pacific; Northeast Pacific; Ocean Drilling Program; organic compounds; orientation; Pacific Ocean; petroleum; petroleum exploration; reservoir properties; reservoir rocks; saturation; veins; well-logging;

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