(Table 1) Mean grain sizes and standard deviations of gas hydrate samples

Methane hydrates are present in marine seep systems and occur within the gas hydrate stability zone. Very little is known about their crystallite sizes and size distributions because they are notoriously difficult to measure. Crystal size distributions are usually considered as one of the key petrophysical parameters because they influence mechanical properties and possible compositional changes, which may occur with changing environmental conditions. Variations in grain size are relevant for gas substitution in natural hydrates by replacing CH4 with CO2 for the purpose of carbon dioxide sequestration. Here we show that crystallite sizes of gas hydrates from some locations in the Indian Ocean, Gulf of Mexico and Black Sea are in the range of 200-400 µm; larger values were obtained for deeper-buried samples from ODP Leg 204. The crystallite sizes show generally a log-normal distribution and appear to vary sometimes rapidly with location.

(Table 1) Carbon, hydrocarbons and observations at DSDP Holes 67-497 and 67-498A

Gas hydrates are icelike materials that form when specific conditions of temperature, pressure, and gas composition are simultaneously satisfied. Among the first descriptions of gas hydrates under natural conditions was that of Hammerschmidt (1940), who found them in pipelines used to transport natural gas. Milton (1976) indicates that conditions are suitable for the presence of gas hydrates in areas affected by permafrost and cites studies suggesting that large quantities of gas exist in hydrate form.

Mexico's oil and gas policy : an analysis /

Prepared by G. J. Pagliano and others.

National gas supply and demand, 1971-1990

Bibliography: p. 151-166

Assessment of environmental fate and effects of discharges from offshore oil and gas operations /

"WH-553"--Cover.

Seventh report on the oil and gas fields of western Pennsylvania. For 1887, 1888, with additional unpublished well records.

Mode of access: Internet.

A restudy of the Staunton gas pool /

Originally published separately as three extracts from Bulletin no. 44.

Oil and gas development and possibilities in east-central Illinois. (Clark, Coles, Douglas, Edgar and parts of adjoining counties)

At head of title: State of Illinois. Department of registration and education. Division of the state geological survey.

Oil and gas development in Illinois during 1950 /

"Reprinted from Statistics of oil and gas development and production covering 1950, A.I.M.E."

Oil and gas development and possibilities in parts of Eastern Illinois.

Bibliographical footnotes.

Oil and gas resources of Kansas ...

Mode of access: Internet.

Michigan's oil and gas fields.

Vols. for 1964- issued as even numbered issues of its Annual statistical summary.

Investigations in the gas and oil fields of Alberta, Saskatchewan, and Manitoba,

Mode of access: Internet.

Summary of operations; annual report of the State Oil and Gas Supervisor.

First-third reports, 1915/16-1917/18, issued as California State Mining Bureau Bulletin no. 73, 82, 84.

Michigan's oil and gas fields.

Mode of access: Internet.