The Trident 1 is a jack-up rig. The legs are raised high for towing by tug boats to location where the 3 anchors from each corner keep it on location until the steel legs are lowered to the sea bed. The vessel is raised slowly above the water to an air gap of 25 feet. Normal drilling position is as shown here.
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
The Trident 1 is a jack-up rig. The legs are raised high for towing by tug boats to location where the 3 anchors from each corner keep it on location until the steel legs are lowered to the sea bed. The vessel is raised slowly above the water to an air gap of 25 feet. Normal drilling position is as shown here.
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.
Drilling platform
An off-shore oil rig on a production/drilling platform (artificial island fabricated from steel). It is shown here without the drilling tender which will be positioned just under the window maker which is shown here at extreme right, hanging at an angle of 45 degrees. Another option is to install every thing on the drilling platform without using a tender. For that you will need a larger platform with subsequent increase in costs. The crane barge CB2 is shown in the background. It has just installed the derrick set on to the drilling platform.Margie
Crew change
Crew change on the drill ship Danwood Ice. This is a Puma helicopter as contracted by Britow Helicopters. Previously Shell used their company owned Sikorsky which are much larger. A drill ship has its own propeller. Some modern drill ships can remain on location during drilling operations by using a computer controlled device which activates the powerful side thrusters. The Danwood Ice used anchors. The moon pool is located in the centre. This drill ship has a sauna with a small swimming pool on board! The accommodations were luxurious and the food was good. It has a free Coke dispenser and an ice-cream machine in the galley!Monday, July 11, 2005
Friday, July 08, 2005
Heavy land rig




