Because the Perdido Regional Development involves three widely spaced, ultra-deepwater fields whose reservoirs are made up of older rock with tighter porosity and permeability along with low temperatures and pressures, Shell Exploration and Production (Shell) decided early on to handle all production via equipment placed on the sea floor, including artificially lifting production liquids to the Perdido spar topsides from a water depth of more than 8,000 ft (2439m).