BROVIG OFFSHORE

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.