Significant attention is being given to exploration on the Continental Slope of the Gulf of Mexico. There are over 2.7 million acres under lease in water depths over 1,000 ft. Conventional fixed-platform developments become very expensive as water depths exceed 1,000 ft., and in some situations the recoverable reserves will not economically justify a fixed platform. Due to technical and economic constraints imposed by this environment, development systems and techniques other than the fixed platform are being seriously considered.
Present unconventional offshore installations, which were developed for marginal fields in the North Sea and other areas of the world, provide field-proven alternatives in the selection of a development system for deep water. A comparison is made here of the technical and economic aspects of such alternatives.