371. Oil wells and rigs
Oil platforms are piled and anchored permanently to the seabed. They are not movable objects. Rigs are completely self contained and mobile units. A drill ship even has its own motor and propeller; whereas jack-ups and semi-subs need to be towed to location (fixed by GPS) by powerful tugs (Smit Lloyd). In Nigeria swamp barges and land rigs are more common.
Saturday, July 23, 2005
Trident 1
Wednesday, July 20, 2005
Semi-submersible
Monday, July 18, 2005
Platform rigs
Saturday, July 16, 2005
Tender assisted rigs
Tuesday, July 12, 2005
Donkey
An oil well in Brunei. It produces very little crude, maybe 50 to 100 barrels/day? The well is shallow and probably drilled more than 50 years ago. Since oil was discovered off-shore, not many new production wells were drilled on land after 1970. An off-shore well will flow without pumping, probably for 10 years or more; producing as much as 1000 barrels/day! There are about 800 wells out there in the South China Sea off-shore Brunei, Sarawak and Sabah. Some of these are gas wells producing natural gas.
After about 10 years the well pressure slowly declines. Other methods (eg. gas lifting) are used to enable the old wells to continue production for a few more years. Finally, a pump (donkey) will be installed to continue extraction of crude for another 20 years or more. Well No: 1 a shallow well on the Canada Hill in Miri produced oil for over 50 years. Some wells in the Seria land fields near Anduki have been producing even longer.