Within Five Years, Hydrate Exploitation Can Be a Reality in the Northern Gulf of Mexico

A. Lowrie¹, C. Lutken², and P. A. Dean
¹ Consultant, Picayune, MS
² Mississippi Mineral Resources Institute, Mississippi University, MS

Hydrates and associated free gases exist within the shallow sub-surface of the Gulf waters in the interval beneath 100-500 meters and 2-3 kilometers. Hydrate occurrence is dependent on the chemistry of the original natural gases and their temperature and pressure regime. At depths circa one to two kilometers, the range of hydrate stability is approximately 100 to 300 meters; with gas trapped beneath the hydrate.

Hydrates are routinely described from along the continental Gulf margin, of the northern Gulf of Mexico. Seismic reflection and drilling data are adequate to locate and map these hydrates and associated free gases.

Exploration involves locating and measuring exploitable potential reservoirs. Exploitation requires conversion of hydrates into free gases or harvesting the associated gases. It also involves determining both the likelihood of removing gases safely and the maintenance of the structural integrity of the area being mined. A structural collapse and consequent catastrophic release of trapped gases would possibly impact stability of the continental margin and affect regional climate. In either scenario a judiciously designed drilling program is mandatory.

Seafloor and subsurface monitoring must be utilized during and after exploitation, including a seismic network and subsurface monitoring of boreholes for temperatures, pressures, and the migration of species into the sector. Monitoring of changes within the continental margin region may be sufficient to prevent failure and maintain the stability and continuity of a reservoir being exploited. Employing state-of-the-art monitoring via seismic reflection and borehole measures, present technology can probably exploit hydrates successfully within five years.

AAPG Search and Discovery Article #90032©2004 GCAGS 54th Annual Convention, San Antonio, Texas, October 10-12, 2004