The Oil Spill in the Gulf of Mexico All images on engineering attempts to control or stop the spill are copyright of BP plc. Information up to June 17, 2010
The Deepwater Horizon rig, built in 2001 by Hyundai Heavy Industries, was 120 meters long and 78 meters wide. It was a semisubmersible drilling platform , with more than 120 crew aboard and it was located some 50 miles southeast of the Mississippi Delta and contained an estimated 700,000 gallons of #2 Fuel Oil or Marine Diesel Fuel for its own power generation. Power supply to the Deepwater Horizon was generated using six Wartsila 18V32 diesel engines rated 9775 hp each, driving six ABB AMG generators of 7000 kW at 11,000 volts AC.
At approximately 10pm on Tuesday, April 20, an explosion rocked Transocean's Deepwater Horizon drilling rig resulting in the loss of 11 crew members and the sinking of the rig two days later.
When the burning rig sank on April 22, so too did the pipe connecting the rig to the 5,000-foot-deep (1,500-meter-deep) oil well. That bent, ruptured pipe is the source of the thousands of barrels still spewing daily into the Gulf.
Deepwater Horizon platform sank completely on April 22nd
Attempts to control or stop the spill After the accident, BP engineers have attempted a number of techniques to control or stop the oil spill such as: May 7 & 8 The Cofferdam Containment Dome May 14 The Riser Insertion Tube May 26 The “Top Kill” Heavy Mud Injection June 3 (LMRP) Cap Containment System. June 16 Connecting with hoses the BOP to the Q4000 .
The Cofferdam containment dome The first and fastest was to place a 125 tonne (280,000 lb) container dome over the largest of the well leaks and pipe the oil to a storage vessel on the surface. This specially-built containment chamber, or "dome" on the sea floor with a connection system called a riser to flow the leaking oil to the Discoverer Enterprise drillship, the capacity to recover oil will go up to up to 15,000 barrels of oil per day. BP deployed the system on May 7–8 but it failed when gas leaking from the pipe combined with cold water to form methane hydrate crystals that blocked up the steel canopy at the top of the dome.
Preparations to deploy the Cofferdam from the supply ship via a crane on the Helix Q4000 in the Gulf of Mexico. May 6, 2010
The Riser Insertion Tube.- On May 14 , engineers began the process of positioning a 4 inch (100 mm) wide riser insertion tube tool into the 21 inch (530 mm) wide burst pipe. After three days, BP reported the tube was working. Collection rates varied daily, the average being 2,000 barrels (84,000 US gallons) a day.
The “Top Kill” option. BP next tried to shut down the well completely using a technique called "top kill". The process involves pumping heavy drilling fluids through two 3 inch (7.6 cm) lines into the blowout preventer that sits on top of the wellhead. This would first restrict the flow of oil from the well, which then could be sealed permanently with cement. The top kill procedure commenced on May 26. On May 29, BP announced that the attempt to clog the ruptured oil well with heavy mud failed.
The (LMRP) Cap Containment System. The next contingency option was the Lower Marine Riser Package (LMRP) Cap Containment System. The operational plan first involved cutting and then removing the damaged riser from the top of the failed blowout preventer (BOP) to leave a cleanly-cut pipe at the top of the BOP's LMRP. The cap is designed to be connected to a riser from the Discoverer Enterprise drillship and placed over the LMRP with the intention of capturing most of the oil and gas flowing from the well. The cap was finally attached on June 3. The amount of oil recovered by this cap was much more than expected and since the maximum oil processing capacity of the Discoverer Enterprise Drillship is 10,000 barrels per day, the rest of the oil captured in the cap is being exhausted to the ocean through the two venting nozzles available in the containment cap. After this experience the total flow of the spill is estimated now to be between 25,000 to 40,000 barrels per day.
Connecting with hoses the BOP to the Q4000 Drilling Vessel On June 16, BP announced today that oil and gas is flowing through a second containment system attached to the Deepwater Horizon rig’s failed blow out preventer (BOP). This system uses the hoses and manifold that were deployed for the top kill operation to take oil and gas from the failed Deepwater Horizon blow-out preventer (BOP) through a separate riser to the Q4000 vessel on the surface, in addition to the LMRP cap system. The Q4000 uses a specialized clean-burning system to flare oil and gas captured by this second system. This system is intended to increase the overall efficiency of the containment operation by possibly increasing the amount of oil and gas that can be captured from the well. Operations continue to stabilize and optimize the performance of this second containment system. “ Neither the new capture system nor the LMRP containment cap system has ever before been deployed at these depths and conditions, and their efficiency and ability to contain the oil and gas cannot be assured.”(BP plc)
Direct Connect with hoses from the BOP to the Q4000 Drill Vessel
Relief Wells – The Long term Solution Admiral Thad W. Allen, the Coast Guard commander, said that the only solution to the problem would be the successful completion of relief wells to finally stop the flow from the bottom of the 18,000-foot-deep well, a job that will not be completed until August at the earliest. BP crews have begun to drill two relief wells in the Gulf of Mexico to stem the flow from the MC252 well. A drilling rig drills a relief well or second well to intersect the original, flowing well as deeply as possible. A specialized heavy liquid is then pumped into the flowing well to bring it under control. This liquid is denser than oil and so exerts pressure (known as hydrostatic pressure) to stem the flow of oil. Once the flow is stopped, the well can be returned to a safe condition.