Top 5 Deadliest Oilrigs Disaster

5. GLOMAR JAVA SEA DRILLSHIP

Rig: Glomar Java Sea Drillship

Date: October 1983

Operator: Arco

Location: South China Sea

Fatalities: 81

The U.S. drillship GLOMAR JAVA SEA, with 81 persons onboard, capsized and sank in the South China Sea at a position approximately 63 nautical miles southwest of Hainan Island, People's Republic of China and 80 nautical miles east of the Socialist Republic of Vietnam. Prior to the sinking, the GLOMAR JAVA SEA had secured drilling operations due to the severe effects of tropical storm 'LEX' approaching from the east of the drilling site.

At 2348 local time, the Assistant Rig Manager, onboard the drillship, called Global Marine's office in Houston, Texas and reported that the drillship had a 15 deg starboard list of unknown origin and was experiencing 75 knot winds over the bow. Communications were cut off during the conversation, and all attempts to re-establish contact failed. At about 2351 the GLOMAR JAVA SEA capsized and within minutes sank in 317 feet of water. An extensive search was conducted but no survivors were found. A diving expedition found the wreck in an inverted position approximately 1600 feet southwest of the well site. The wreck was searched and 31 of the 36 bodies found were recovered. The remaining 45 persons are missing and presumed dead.

4. OCEAN RANGER

Rig: Ocean Ranger

Date: February 1982

Operator: Mobil Oil Canada Ltd.

Location: Hibernia Field, North Atlantic

Fatalities: 84

Ocean Ranger was designed by Ocean Drilling and Exploration Company, Inc. (ODECO) and constructed in 1976 by Mitsubishi Heavy Industries's Yard in Hiroshima, Japan. The vessel was a self-propelled large semi-submersible design with a drilling facility and living quarters. She was one of the largest semi-submersibles working offshore in the early 1980s.

At about 1900 hours local time, the nearby Sedco 706 experienced a large, powerful wave which damaged some items on deck and caused the loss of a life raft. Soon after, radio transmissions were heard from Ocean Ranger, describing a broken portlight (a porthole window) and water in the ballast control room, with discussions on how best to repair the damage. Ocean Ranger reported experiencing storm seas of 55 feet (17 m), with the odd wave up to 65 feet (20 m), thus leaving the unprotected portlight at 28 feet (8.5 m) above mean sea level vulnerable to wave damage.

At 0052 hours local time, on 15 February, a Mayday call was sent out from Ocean Ranger, noting a severe list to the port side of the rig and requesting immediate assistance. This was the first communication from Ocean Ranger identifying a major problem. The standby vessel, the M/V Seaforth Highlander, was requested to come in close as countermeasures against the 10—15 degree list were proving ineffective. The onshore MOCAN supervisor was notified of the situation, and the Canadian Coast Guard and Mobil-operated helicopters were alerted just after 0100 hours local time. The M/V Boltentor and the M/V Nordertor, the standby boats of the Sedco 706 and the Zapata Ugland respectively, were also dispatched to Ocean Ranger to provide assistance. At 0130 hours local time, Ocean Ranger transmitted its last message: "There will be no further radio communications from Ocean Ranger. We are going to lifeboat stations." Shortly thereafter, in the middle of the night and in the midst of atrocious winter weather, the crew abandoned the rig. The rig remained afloat for another 90 minutes, sinking between 0307 and 0313 hours local time.

Whilst the rig was provided with an Emergency Procedures Manual which detailed evacuation procedures, it is unclear how effectively the rig evacuation was carried out. There is evidence that at least one lifeboat was successfully launched with up to 36 crew inside, and witnesses on the M/V Seaforth Highlander reported seeing at least 20 crew members in the water at the same time, indicating that at least 56 crew successfully evacuated the rig. The United States Coast Guard report speculated that 'these men either chose to enter the water directly or were thrown into the water as a result of unsuccessful lifesaving equipment launching'. Rescue attempts by the standby vessels were hampered by the adverse weather conditions and the conclusion that the standby boats were neither equipped nor configured to rescue casualties from a cold sea.

As a result of the severe weather, the first helicopter did not arrive on scene until 0230 hours local time, by which time most if not all of Ocean Ranger's crew had succumbed to hypothermia and drowned. Over the next week, 22 bodies were recovered from the North Atlantic. Autopsies indicated that those men had died as a result of drowning while in a hypothermic state.

3. SEACREST DRILLSHIP

Rig: Seacrest Drillship

Date: November 1989

Operator: Unocal

Location: Gulf of Thailand

Fatalities: 91

Details of the Seacrest capsize tragedy are sketchy. Newspaper reports state that 97 crew were working aboard the 4400-tonne Unocal-owned drillship in the South China Sea, around 430 kilometres south of Bangkok, when it capsized in heavy seas during Typhoon Gay. No distress signals were heard from the Seacrest and none of its lifeboats were found, suggesting that the capsize occurred too quickly for the crew to respond.

The ship was reported missing on Saturday, 4 November 1989 and a search helicopter located the Seacrest floating upside-down 0815 local time on Sunday, 5 November 1989. Two rescue crew were landed on the up-turned hull of the ship to check for survivors. They tapped on the hull in the hope that some crew may have survived in an airpocket inside the ship, but received no reponse. Over the following days, Thai Navy divers searched the ship and found two bodies in the hull.

2. ALEXANDER L. KEILLAND

Rig: Alexander L. Kielland

Date: March 1980

Operator: Philips Petroleum

Location: Ekofisk Field, Norwegian Continental Shelf

Fatalities: 123

The Alexander L. Kielland was a Norwegian semi-submersible drilling rig that capsized whilst working in the Ekofisk oil field in March 1980 killing 123 people. The capsize was the worst disaster in Norwegian waters since World War II. The rig, located approximately 320 km east from Dundee, Scotland, was owned by the Stavanger Drilling Company of Norway and was on hire to the U.S. company Phillips Petroleum at the time of the disaster. The rig was named after the Norwegian writer Alexander Lange Kielland.

In driving rain and mist, early in the evening of 27 March 1980 more than 200 men were off duty in the accommodation on the Alexander L. Kielland. The wind was gusting to 40 knots with waves up to 12m high. The rig had just been winched away from the Edda production platform. Minutes before 18.30 those on board felt a 'sharp crack' followed by 'some kind of trembling'. Suddenly the rig heeled over 30° and then stabilised. Five of the six anchor cables had broken, the one remaining cable preventing the rig from capsizing. The list continued to increase and at 18.53 the remaining anchor cable snapped and the rig turned upside down.

130 men were in the mess hall and the cinema. The rig had seven 50-man lifeboats and twenty 20-man rafts. Four lifeboats were launched, but only one managed to release from the lowering cables. (A safety device did not allow release until the strain was removed from the cables.) A fifth lifeboat came adrift and surfaced upside down; its occupants righted it and gathered 19 men from the water. Two of Kielland's rafts were detached, three men being rescued from them. Two 12-man rafts were thrown from Edda and rescued 13 survivors. Seven men were taken from the sea by supply boats and seven swam to Edda.

No-one was rescued by the standby vessel which took an hour to reach the scene. Of the 212 people aboard 123 were killed, making it the worst disaster in Norwegian offshore history since WWII. Most of the workers were from Rogaland.

1. PIPER ALPHA

Rig: Piper Alpha Platform

Date: July 1988

Operator: Occidental

Location: UK Continental Shelf

Fatalities: 167

The Piper Field was discovered by Occidental in January 1973, with the Piper Alpha platform becoming operational in 1976. Located about 120 miles north-east of Aberdeen, the platform initally produced crude oil. In late 1980, gas conversion equipment was installed allowing the facility to produce gas as well as oil. A sub-sea pipeline, shared with the Claymore platform, connected Piper Alpha to the Flotta oil terminal on the Orkney Islands. Piper Alpha also had gas pipelines connecting it to both the Tartan platform and to the separate MCP-O1 gas processing platform. In total, Piper Alpha had four main transport risers: an oil export riser, the Claymore gas riser, the Tartan gas riser and the MCP-01 gas riser.

On 06 July 1988, work began on one of two condensate-injection pumps, designated A and B, which were used to compress gas on the platform prior to transport of the gas to Flotta. A pressure safety valve was removed from compressor A for recalibration and re-certification and two blind flanges were fitted onto the open pipework. The dayshift crew then finished for the day.

During the evening of 06 July, pump B tripped and the nightshift crew decided that pump A should be brought back into service. Once the pump was operational, gas condensate leaked from the two blind flanges and, at around 2200 hours, the gas ignited and exploded, causing fires and damage to other areas with the further release of gas and oil. Some twenty minutes later, the Tartan gas riser failed and a second major explosion occurred followed by widespread fire. Fifty minutes later, at around 2250 hours, the MCP-01 gas riser failed resulting in a third major explosion. Further explosions then ensued, followed by the eventual structural collapse of a significant proportion of the installation.

167 men died as a result of the explosions and fire on board the Piper Alpha, including two operators of a Fast Rescue Craft. 62 men survived, mostly by jumping into the sea from the high decks of the platform. Between 1988 and 1990, the two-part Cullen Inquiry established the causes of the tragedy and made recommendations for future safety regimes offshore. 106 recommendations were made which were subsequently accepted and implemented by the offshore operators.