The Jurong Rock Caverns, Singapore's first subterranean cavern storage facility for oil products, were officially opened on Tuesday after eight years of construction.

Located 150m below energy and chemicals hub Jurong Island, the $950 million facility consists of five nine-storey high underground caverns.

It will be used to store 1.47 million cubic m of liquid hydrocarbons such as crude oil and condensate - equivalent to 600 Olympic-sized swimming pools.

Liquid hydrocarbons are usually stored in large tanks above ground. The Jurong Rock Caverns will free up about 60ha of land, which can be used for higher value-added activities, industrial landlord JTC said at Tuesday's launch.

Two of the five caverns have already been leased to Jurong Aromatics Corporation, which will be using them to store feedstock for its aromatics plant. The remaining three caverns are expected to be operational by 2016.