This page is now a bit of
history but we have left it in for interest, and on the off chance that some-one
might tell us what the Crystal Ocean and Crystal Sea are doing now. This was a
good idea which was unsuccessful except that one of them was central to the
recovery of oil from one of the tankers which sunk in the Eastern Atlantic.
Since then they have languished in an African port and were bought by some-one
during the summer of 2004.
The Well Test Vessel Crystal Ocean
Photo: Vic Gibson
The Crystal Ocean is the latest Floating Production, Storage and Well
Testing Vessel to be brought into service by Brovig Offshore. It is a UT729 designed by
Ulstein International and was built at Kvaerner Govan, and in the middle of February it
spent several days parked in the centre of Aberdeen being shown off to the industry.
For those not familiar with the details of the well testing process,
during exploration a rig will drill a well, and if the seismic work has been well done,
and suitably interpreted at some point the drill bit will enter the reservoir but the oil
will be kept down there firstly with drilling fluid and then if necessary with well
control hardware. There-after arrangements will be made to test the well for the purpose
of determining the precise constituents of the oil and the potential flow rate. In order
to do this well testing equipment is shipped out and placed on the deck of the rig and the
well is flowed though this equipment. Of course the oil must go somewhere, and the easiest
way of dealing with it is to burn it. Apart from providing a photo opportunity this is a
waste of a natural resource, and a potential pollutant, and so in environmentally sensitive
areas the Crystal Sea and now the Crystal Ocean may be called in to receive the flow.
Both of them are provided with processing equipment on deck. The
Crystal Ocean is able to process 6000 cubic meters or 40,000 barrels of oil per day and
has a storage capacity of 6,600 cubic meters. The fact that the ship can only store about
one day's production at maximum though-put is not really a disadvantage. Very few single
wells can produce at such volumes, and in any case the well is flowed for relatively short
periods of time. One assumes that if the ship had to return to port after one day's
testing it would be met by euphoric oil executives armed with champagne and streamers
The Crystal Ocean is 101 meters long and displaces 14,500 tonnes. This
is the same as a medium sized traditional cargo ship. It is longer than most of the oil
rigs it is going to work with and would be easily capable of causing serious impact damage
if any system failed.
In order to maintain station during the testing operation and to get
close enough to pass the hose the ship is provided with a Konsberg Simrad DP system which
interfaces with two 2200 kW azimuthing thrusters aft and two 1100 kW tunnel thrusters and
one 880 kW azimuthing thruster forward. Main power is provided by four Bergen diesels
developing 14,400 BHP. As well as the DP station, the bridge is provided with a number of
joystick positions, aft forward and at each bridge wing. In addition individual operation
of all controls is provided forward and aft.
A full report on the Crystal Ocean appears
in the February edition of the Offshore Support Journal.
A check on the DNV site
indicates that both the Crystal Sea and the Crystal Ocean
are still in service under different ownership. The Crystal
Sea is now called the BW Athena and may be being used as a
Updated a bit on 28th January 2014