U.S., Gulf of Mexico Block MC 687
Landmark: Shell Mensa is the world’s deepest subsea production development at completion and has the longest tieback to it's host at 68 miles (110 km).
The Shell Mensa project involved the development of the Mensa natural gas field located in the Gulf of Mexico 140 miles (225 km) southeast of New Orleans in water depths of 5,300 ft (1,610 m). The initial development included three subsea electro-hydraulic-controlled subsea trees individually connected via 6" flowlines to a subsea manifold located approximately 5 miles (9 km) away. An additional subsea tree was installed five years after the initial development. A single 12" pipeline transports the gas 63 miles (102 km) from the manifold to the West Delta 143 shallow-water platform.
The gas is processed and commingled with other gas produced at the same facility and transported to shore by pipeline. Shell Mensa was installed in 1997 and early 1998 and has been in production since April 1998. A fourth Mensa well was installed in 2003. The new well’s flowline and umbilical were tied back to the spare hubs in the Mensa manifold. An 8" flowline was used between the fourth well and the manifold for increased flow rate.