USUMACINTA BLOWOUT
October 23, 2007
Bay of Campeche, G.O.M
Overview
The Usumacinta was a mat type jack up drilling rig that was owned by Perforadora Central and operated out of Mexico. The primary operational role of the jack up rig was to move between well locations and carry out drilling support operations for stationary platforms.
In October 2007, the Usumacinta vessel was contracted to drill a well for PEMEX from the Kab-101 platform in the Bay of Campeche, approximately 75 km off the coast of Tabasco region near the port of Dos Bocas. The Bay of Campeche is the second most productive oil field in the world and contributes to 2/3rd of Mexico’s crude output.
The Kab-101 platform was a light production platform that produced approximately 5,700 bbls of oil and 700,000 cf of natural gas from two separate oil wells. The Usumacinta rig was contracted to drill the third well, Kab-103.
The Incident
On 21st October 2007, the Usumacinta arrived in position next to the Kab-101 platform to finish drilling the Kab-103 well. By 24th October, a cold front moved across the Bay of Campeche resulting in wind speeds of 130 km/hr and waves as high as 8 meters creating severe weather conditions.
The weather conditions caused strong oscillations to the rig that caused the cantilever to collide with a production tree valve on the Kab-101 platform. Oil and gas began leaking from the damaged tree on 23rd October 2007.
Following the incident, the sub-surface safety valves of wells 101 and 121 were closed. However, either the crew could not close the valves completely or the collision had affected the integrity of the valves. In any case, the well continued to flow even after the attempt to close the safety valves.
At the time, all 81 personnel on board were present. On 13th November, during the course of containment work aboard the Kab platform, the leaking oil and gas ignited that was eventually put out on 14th November. However, the hydrocarbons ignited for the second time on 20th November. The second fire was severe and caused extreme damage to the structure.
The Aftermath
Of the 81 personnel on board and 5 sailors who were involved in the incident, PEMEX reported that there were 58 survivors. There were 21 reported deaths, and 1 rescue team member was lost and presumed dead.
Initially, the hydrocarbon spill from the Kab platform was estimated at 442 bbls of light crude per day. PEMEX estimated that ~ 40% of the spilled hydrocarbons had evaporated. PEMEX utilized a variety of chemicals to recover a total of 8,701 bbls of crude. It was estimated that ~ 5,000 bbls could not be recovered.
Root Causes
The Usumacinta incident was caused due to incapability of the rig to resist extreme motions due to extreme weather conditions. If the vessels operating offshore are adequately designed for the worst possible storm conditions, such an event might be avoided.
Way Forward
The Usumacinta incident was caused due to incapability of the rig to resist extreme motions due to extreme weather conditions. If the vessels operating offshore are adequately designed for the worst possible storm conditions, such an event might be avoided.
Reference
The Usumacinta Disaster, Chris Hanlon, Memorial University, March 2013.
