Natural gas hydrates of Circum-Pacific margin-a future energy resource
Natural gas hydrates are probably present within the uppermost 1100 m (3600 ft) of oceanic sediment in the following regions of outer continental margins rimming the Pacific Ocean basin: (1) the continental slope east of the North Island of New Zealand; (2) the landward slope of the Nankai Trough off Japan; (3) the continental slope of the northwestern and eastern Aleutian Trench; (4) the continental slope off northern California; (5) the landward slope of the Middle America Trench off Central America; (6) the landward slope of the Peru-Chile Trench; and (7) the basinal sediment of the Ross Sea and the continental margin off Wilkes Land, Antarctica. These gas hydrates likely contain and cap significant quantities of methane. Geophysical evidence for gas hydrates is found mainly in the widespread occurrence on marine seismic records of an anomalous reflection event that apparently marks the base of the gas-hydrate zone. Geochemical evidence consists of analyses of gases and interstitial fluids obtained from drilling in offshore sedimentary deposits, particularly at nine DSDP sites cored adjacent to the Middle America Trench where gas hydrates were recovered. Natural gas hydrates will probably be identified in many other Circum-Pacific regions as exploration for offshore petroleum moves into deeper waters over continental and island-arc slopes. Initially, these gas hydrates will probably not be considered as potential energy resources, but special drilling procedures may be needed to penetrate them safely. However, if appropriate reservoirs are found in association with the gas hydrates, then an important energy resource may be discovered.
- Research Organization:
- Geological Survey, Menlo Park, CA
- OSTI ID:
- 7052009
- Report Number(s):
- CONF-8608105-
- Journal Information:
- Am. Assoc. Pet. Geol., Bull.; (United States), Journal Name: Am. Assoc. Pet. Geol., Bull.; (United States) Vol. 70:7; ISSN AAPGB
- Country of Publication:
- United States
- Language:
- English
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