Singapore: JTC to study impact of seepage in Jurong cavern

It calls tender for study on interaction between water seepage and oil
Ronnie Lim Business Times 13 Dec 10;

A YEAR into construction of the $940 million phase one of the Jurong Rock Cavern (JRC), JTC Corporation is carrying out studies on the effect of seepage water on crude oil and oil products that will be stored there from mid-2013.

Forming part of its on-going studies on underground oil storage, JTC's latest investigation covers normal groundwater seepage - which is salty in nature - from the rock walls into the caverns.

JTC had earlier carried out environmental impact studies as far back as 2006, after it found the JRC to be economically and technically viable.

A part of the JRC - located at the Banyan LogisPark portion of Jurong Island - will be beneath the Banyan Basin sea channel there, with earlier reports indicating that excavation work will be done 130 metres below the seabed.

Water pressure will keep the oil contained within the generally unlined rock caves, JTC said earlier.

The corporation, which has just called a tender for an experimental study on the interaction between water seepage and oil, explained in a background note that 'part of the water will have free contact with the stored product (for example, crude oil) ... such as water droplets falling from the cavern roof, and water that will percolate from the cavern walls and cavern bottom'.

'Water can be emulsified in the product and can accumulate at the cavern bottom forming a water bed,' it added.

The purpose of the JTC study, which includes several chemical tests, is to analyse the salt and sulphur content in both the oil and seepage water and 'the evolution of the water content in the crude oil'.

JTC wants the appointed consultant to prepare a 'test cell' where seepage water will be continuously injected at the cell top as fine droplets, which will then fall freely to the cell bottom where they accumulate as a layer. The water will then be discharged from the cell bottom.

Energy consultant Ong Eng Tong told BT there are generally no technical issues regarding water mixing with oil, as oil is lighter and the water will eventually settle down and can be easily drained off.

'Ethanol, which is mixed with gasoline to produce 'green' gasoline, is the only oil product which will be affected as its microscopic properties attract water,' he said. 'As for salt, this affects fuel oil as the salt won't settle.'

The latest JTC study comes a year after South Korea's Hyundai Engineering & Construction embarked on phase one of the JRC - with the first two caverns providing 480,000 cubic metres of oil storage expected to be ready in the first half of 2013.

The entire phase one will involve eight kilometres of tunnels, with five caverns made up of two storage galleries, with each gallery being 340m long, 20m wide and 27m high. About nine-storeys high, each gallery is large enough to contain water from 64 Olympic-size pools.

JRC's first confirmed customer is the Jurong Aromatics Corporation (JAC) consortium, which is set to start building a US$2.4 billion petrochemicals complex on Jurong Island next year.

The JAC facility is slated to come on-stream in 2014, soon after JRC's completion.