Brooks, James M.¹, Bernie B. Bernard², Neil S. Summer²
(1) TDI-Brooks Int'l Inc, College Station, TX
(2) TDI-Brooks, College Station, TX

ABSTRACT: Gas Hydrates in Seabed Sediments Offshore Trinidad/Barbados

Many of the discoveries and studies of gas hydrates in shallow seafloor sediments in the Gulf of Mexico and West Africa have resulted from surface geochemical exploration (SGE) coring studies conducted by the authors. In this poster session, we provide new information on the distribution, occurrence, and nature of gas hydrates offshore Trinidad and Barbados.
The Atlantic continental margin offshore Trinidad and Barbados has been the site of gas hydrate recoveries over the last few years from SGE coring programs. This region is much like the northern Gulf of Mexico in that there are numerous sites of macroseepage of oil and gas into shallow seabed sediments. This seepage is generally associated with deep faulting that act as conduits for the upward migration of oil and gas. Gas hydrates are often collected from 6-meter piston cores along with oil/gas seepage over these faults which are often associated with mounds. Gas hydrates were observed in at least 12 cores in water depths from 714 to 2,386-m. Another 20+ cores were suspected to contain hydrates based on gas expansion cracks and headspace gas concentrations. Both biogenic and thermogenic hydrates were observed based on molecular and isotopic compositions. The gas hydrates are often associated with large mounds much like "Bush Hill" in the Gulf. Seven cores over one of these mounds identified visual gas hydrates in five of the cores. Heat flow measurements were acquired that along with gas compositions and water depth can constrain the depth of the hydrate stability zone.

AAPG Search and Discovery Article #90026©2004 AAPG Annual Meeting, Dallas, Texas, April 18-21, 2004.