Oil Rig – A-Cognac
The Cognac is a fixed platform oil rig operated by Shell. It is located in the Mississippi Canyon region of the Gulf of Mexico, in 1,030 feet of water and 105 miles southeast of New Orleans, Louisiana. It was the first deepwater well to be discovered in the gulf.
Today, the Cognac field comprises four Mississippi Canyon leases, Blocks 108, 151, 194 and 195. The first discovery well was drilled in Block 194 in 1975, and that was followed by twelve other wells.
After discovery, a fixed steel platform was constructed in 1977, which consisted of three separate units. Oil production came on line in 1978, and by 1981, two drilling rigs were used to drill 61 wells. The total height of the platform from the sea floor to the top of the drilling rigs is 1,265 feet.
Shell set several world firsts when Cognac was installed:
- The first platform installed beyond the continental shelf.
- The world’s first three-piece offshore platform.
- The heaviest platform, at 59,000 tons.
- The deepest water platform, at 1,030 feet.
- The most well slots on a platform, with 62.
- The first time an underwater hammer was used to secure the structure to the sea bed.
Cognac was taller than the Empire State Building and was recognized as the world’s tallest and heaviest offshore steel structure at the time. The project earned Shell an Outstanding Civil Engineering Achievement award in 1980 by the American Society of Civil Engineers. It also gained recognition in 1982 with an award for Engineering and Installation from the Offshore Technology Conference.
The Cognac development was the sole deepwater field for five years until the Lena field, operated by ExxonMobil, came on line. It continues to produce oil today.
Shell shut down the platform for redevelopment in 1989 to extend the life of the field. The company had confirmed the discovery of several new oil reservoirs within Block 194. The Cognac platform had to be strengthened before the start of redevelopment drilling. A total of 20 redevelopment wells came on stream by 1991 to augment the existing 30 Cognac wells.
In 2012, Shell shut down the platform once again for two years for a retrofit. This project involved inspection and structural repair to the platform, vessels, and piping. It also included repair to 40 wellheads.
Oil from the facility is transported to South Pass 25 via a 12-inch diameter pipeline over a distance of 28 miles. Gas from the Cognac field is piped 20 miles via a 16-inch pipeline to South Pass Block 22, and then connecting to the Southern Natural Gas Romere Pass Pipeline.
Accidents and Injuries
Work on an offshore oil rig is extremely dangerous. Employees have to work with equipment in rough seas and harsh weather. Injuries and deaths can occur from slips and falls, equipment malfunctions, explosions, fires, and drowning.
Workers depend to a large extent on team work, as a bad decision made by one of them can result in a serious accident. A study conducted by the Centers for Disease Control and Prevention over a seven year period up to 2010, showed that the death rate in the oil and gas industry was seven times more than the average for all U.S. workers.