SUBSEA TRENDS

Figure 46 shows the number of subsea completions each year since 1955 (only productive wells were counted).

Figure 46. Number of shallow- and deepwater subsea completions each year. (Click the image to enlarge)

There were fewer than ten subsea completions per year until 1993.

This number increased dramatically throughout the 1990�s. The pie chart within figure 46 shows that shallow-water subsea wells are a significant contribution to the subsea well population in the GOM.

Shallow-water subsea wells accounted for 131 of the 295 total subsea wells in the GOM by yearend 2003. Operators have found subsea tiebacks to be valuable for shallow-water marginal fields because of the extensive infrastructure of platforms and pipelines.

Nonmajor companies have installed nearly all of these shallow-water subsea wells, led by Walter Oil and Gas Corporation with 35 wells. Figure 46 demonstrates the increasing reliance of industry on subsea technology to develop both shallow-water and deepwater fields, beginning in the late 1980�s.

The technology required to implement subsea production systems in deepwater evolved significantly in the last decade.

This evolution is apparent in figure 47, which shows the deepest subsea completion was in 350 ft (107 m) of water until 1988, when the water depth record (GOM) jumped to 2,243 ft or 684 m (Green Canyon 31 project). In 1996 another record was reached with a subsea completion in 2,956 ft (901 m) of water (Mars project), followed by a 1997 subsea completion in 5,295 ft (1,614 m) of water (Mensa project).

Figure 47. Maximum water depth of subsea completions each year. (Click the image to enlarge)

Camden Hills has the deepest production in the GOM to date, in a water depth of 7,216 ft (2,199 m). A listing of productive subsea completions on the GOM Outer Continental Shelf can be found in Appendix G.

Figure 48 further breaks down the subsea completion count into specific water depth ranges.

Figure 48. Water depth of subsea completions.

This figure shows that 70 percent of the subsea completions are in water depths less than 2,500 ft (762 m).