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Apparatus investigates geological aspects of gas hydrates

Oil & Gas Journal

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Abstract

The US Geological Survey (USGS), in response to potential geohazards, energy resource potential, and climate issues associated with marine gas hydrates, has developed a laboratory research system that permits hydrate genesis and dissociation under deep-sea conditions, employing user-selected sediment types and pore fluids.

The apparatus, GHASTI (gas hydrate and sediment test laboratory instrument), provides a means to link field studies and theory and serves as a tool to improve gas hydrate recognition and assessment, using remote sensing techniques.

GHASTLI's use was proven in an exploration well project led by the Geological Survey of Canada and the Japanese National Oil Corp., collaborating with Japan Petroleum Exploration Co. and the USGS. The site was in the Mackenzie Delta region of the Northwest Territories (Mallik 2L-38 drillsite).

From tests on natural methane hydrate-bearing sand recovered at about 1,000 m subsurface, the in situ quantity of hydrate was estimated from acoustic properties, and a substantial increase in shear strength due to the presence of the hydrate was measured.1 2

GHASTI can mimic a wide range of geologic settings and processes. Initial goals involve improved recognition and mapping of gas hydrate-bearing sediments, understanding factors that control the occurrence and concentration of gas hydrates, knowledge of hydrate's significance to slope failure and foundation problems, and analysis of gas hydrate's potential use as an energy resource.

Additional publication details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Apparatus investigates geological aspects of gas hydrates
Series title:
Oil & Gas Journal
Volume:
97
Issue:
40
Year Published:
1999
Language:
English
Publisher:
PennWell Corporation
Publisher location:
Tulsa, OK
Contributing office(s):
Woods Hole Coastal and Marine Science Center
Description:
8 p.
First page:
63
Last page:
70