320 4TH CAN. PERMAFROST CONF. (1982) Natural gas hydrates in Canada

• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Canada; Beaufort Shelf; north slope; permafrost; Alaska; Siberia
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.567.3216; http://pubs.aina.ucalgary.ca/cpc/CPC4-320.pdf

The presence of hydrate in at least 20 northern Canadian wells on- and off-shore has been inferred by the nature of gas release from formations and from geophysical well-log interpretations. In addi-tion, hydrates have been identified in gas fields in Siberia and on the north slope of Alaska. There are extensive data on temperature- pressure relationships for different hydrate compositions. Relating such curves to depth within the earth and superimposing measured geothermal gradients provides a means of predicting the depth zones of occurrence. Maximum thicknesses probably do not exceed 1800 m. In water depths greater than 200 to 300 m, gas-hydrates may be found in sediments at, or close to, the sea-floor. The destruction of the hydrate by changing the thermal regime may lead to problems similar to those associated with bottom-founded structures or pipelines in permafrost terrain. Decom-position of gas-hydrates may occur naturally in areas such as the Beaufort shelf. The resulting large volumes of natural gas may weaken the sediments leading to instability with respect to natural or in-duced loads such as earthquakes. The Soviets estimate that as much as 10%3 (525 Tcf) of gas hydrate may underlie the on-shore areas of the northern Soviet Union. In addition, as much as lO%d of gas hydratemay underlie the