On 24 January 1983, a supply ship collided with a rig in the Iranian Nowruz oil field. This incident caused a rupture of the riser at wellhead n°3, resulting in a spill of crude oil at an estimated rate of 240 m3 a day. Spill response proved difficult as Nowruz oil field was in the Iran/Iraq war zone. After several attempts, well n°3 was capped on 18 September 1983. Eleven people were killed in the operation. The well was then plugged with cement.
Another spill occurred in the same field in April 1983. A nearby rig was attacked by Iraqi bombers. It burnt for two years. Initially, 795 m3 of oil a day was spilt into the sea, but over time the rate slowed down. It was not until March 1985 that well n°4 was capped. The fire was extinguished and the well was plugged with the assistance of divers. Nine men lost their lives in these operations.
The total quantity of oil spilt in the Persian Gulf between 1983 and 1985 is estimated at 260,000 tonnes.
Fate of oil
The spilt oil mixed with water and rose to the surface, forming a heavy, viscous emulsion of 80% water and 20% oil. A slick 700 m long by 400 m wide and 1 to 5 mm thick spread around the site of the eruption. During the first three months following the bombings, south-westerly winds drove the slicks towards the Saudi Arabian coast. Thereafter, north/north-easterly winds fortunately kept them away from the coast. In June 1983, large quantities of tarballs the size of tennis balls were reported, floating just below the water surface.
The use of dispersants was inefficient as the oil had formed an extremely viscous emulsion. Although a vast quantity of response equipment was deployed (skimmers, pumps, booms), only a small fraction of the spill was recovered. This was due to the fact that the spill area was an extremely dangerous war zone. What’s more, boom deployment in the middle of an offshore oil field is a very delicate operation which requires response teams to have specific training they may not necessarily have had. Training courses were therefore carried out in this emergency context near Kharg Island.
The pollution was monitored via a few satellite images and several helicopter overflights.
Date: 24 January 1983
Accident area: Persian Gulf
Cause of spill: collision and act of war
Type of pollutant: crude oil
Quantity spilled: 260,000 tonnes
Structure type: oil rig
Owner: Iranian Offshore Oil Company
Last update: May 2010