The objective of this study is to describe the background setting, water depth. Type of rig, depth of reservoir and unusual characteristics of the BP Operation in the Gulf of Mexico.
On April 22, it is reported that an explosion "ripped the Deepwater Horizon drilling rig in Macondo Exploration Well/Canyon 252 Block 41 miles off the Louisiana coast. A fire raged for about 36 hours before a second blast sank the rig. The well's blowout preventer failed to activate, resulting in the largest oil leak in history." (Gulf, Oil, and Gas, 2011) The Macondo Exploration Well/Canyon 252 Block is located in the U.S. sector of the Gulf of Mexico, approximately 41 miles off the coast of Louisiana. The depth is approximately 5,000 feet and the well drilling depth is 18,000 feet (5,500 m) below the sea level. Reports state that the plans were that the well would be "…plugged and suspended for subsequent completion as a subsea producer." (Gulf, Oil, and Gas, 2011 )
I. Partners and Shareholders
Partners and shareholders include the following with percentage of ownership in the operation.
Figure 1 -- Partners and Shareholders
Anadarko Petroleum Corporation
Mitsui Oil Exploration Co., Ltd.
Source: Gulf, Oil, and Gas (2011)
II. Suppliers, Contractors, and Service Providers
Suppliers, Contractors and Service Providers include those stated as follows:
(1) Halliburton Co. -- Performed cementing work on the Macondo Exploration Well on Canyon 252 Block. A special nitrogen-foamed cement was used which is more difficult to handle than standard cement. A cement bond log documents and evaluation of the integrity of cement work performed on an oil well.
(2) Plant Performance Services (P2S): Plant performance services are a wholly owned subsidiary of Fluor Corporation and was selected by BP to execute two contracts to support the Gulf Coast clean-up efforts.
(3) Transocean: provider and operator of the Deepwater Horizon drilling rig, which is a floating semi-submersible drilling unit, ultra-deepwater, dynamically positioned and column-stabilized drilling rig with $560 million cost built by Hyundai Heavy Industries.
(4) BP Plc -- operator of the Canyon 252 Block.
(5) Cameron International: manufactured and supplied the blowout preventer (BCP) for the Macondo Exploration Well on Canyon 252 Block. (Gulf, Oil, and Gas, 2011)
III. Timeline of Events
February 28, 2009, it is reported that BP filed an exploration and environmental impact plan 52 pages long for the Macondo well. The plan stated it "unlikely that an accidental surface or subsurface oil spill would occur from the proposed activities." In the event an accident did take place, the plan stated that due to the well-being 48 miles (77 km) from shore and the response capabilities that would be implemented, no significant adverse impacts would be expected. The Department of the Interior exempted BP's Gulf of Mexico drilling operation from a detailed environmental impact study after concluding that a massive oil spill was unlikely." (Gulf, Oil, and Gas, 2011) On June 22, 2009 engineers for BP stated a warning that the "metal casing for the blowout preventer might collapse under high pressure." (Gulf, Oil, and Gas, 2011) October 7, 2009 the Marianas rig was used by BP to begin drilling the Macondo Well. Marianas rig was damaged by Hurricane Ida on November 9, 2009 and the rig was replaced by Transocean Deepwater Horizon drilling rig. (Gulf, Oil, and Gas, 2011, paraphrased) On February 15, 2010, the drilling was commenced on the Macondo Well with the Transocean Deepwater Horizon drilling rig. (Gulf, Oil, and Gas, 2011, paraphrased) The rig is reported to have experienced problems associated with "drilling mud falling into the undersea oil formation, sudden gas releases, a pipe falling into the well, and at least three occasions of the blowout preventer (BOP) leaking fluid as an accident damaged a gasket on the blowout preventer." (Gulf, Oil and Gas, 2011) On April 9, 2010, it is reported "BP drilled the last section with the wellbore 18,360 feet below sea level but the last 1,192 feet need casing." (Gulf, Oil and Gas, 2011) The report states that BP "…drilled last section with the wellbore 18,360 feet below sea level but the last 1,192 feet need casing. Halliburton recommends Liner/Tieback Casing that will provide four redundant barriers to flow. BP chooses to do a single liner with fewer barriers that is faster to install and cheaper." (Gulf, Oil and Gas, 2011) The drilling of Deepwater Horizon was completed on April 17, 2010 and the well prepared to be cemented so that the oil could be retrieved by another rig. BP knew at this time that problems existed with the BOP, which was "supposed to shut off the well in the event of an emergency." (Gulf, Oil and Gas, 2011 ) It is reported that on April 17, 2010, the drilling was completed by Deepwater Horizon and the well was "prepared to be cemented so that another rig will retrieve the oil. BP also knew that there were problems with the BOP, which was supposed to shut off the well in the event of an emergency." (Gulf, Oil and Gas, 2011) On April 14, 2010 oil accumulation is reported as having been "discovered on the well and Schlumberger flied a crew to conduct a cement bond log to determine whether the cement has bonded to the casing and surrounding formations." (Gulf, Oil and Gas, 2011) An explosion is reported to have ripped through the drilling rig in the well on April 20, 2010 and on April 22, 2010, a second blast sank the drilling rig. The well's blowout preventer did not activate and an oil leak ensued. On April 25, BP had made plans to drill two relief wells, a primary and a backup in the Canyon 2.52 block. The primary relief well to intersect with the blown-out Macondo well at about 18,000 feet beneath the water's surface, or 13,000 feet beneath the sea floor, and pump it with mud and cement to shut it. If it fails, the backup well would take over. The relief wells are BP's final option to contain or stop the oil escaping from its Macondo well, also the Transocean drilling rig Development Driller III was moved into position to drill a second well, the first of two relief wells. A second drilling rig, Transocean's Discoverer Enterprise, is en route." (Gulf, Oil and Gas, 2011) Work started drilling on the first relief well on May 2, 2010, which is estimated to have taken approximately three months to complete from the start of drilling. BP began trying another experimental approach on May 5, 2010 through "fabrication of a dome-like containment device to divert oil at the wellhead on the seabed. It is planned to lower the dome over one of the leak sites on the seabed and then connect it by pipe to a specialist vessel at the surface. This system is designed to help capture the oil at the seabed and collect it securely for processing." (Gulf, Oil and Gas, 2011) On May 7, 2010, a steel dome weighing approximately 100 tons was deployed. On May 16, work began on the second relief well and this took three months to complete form the commencement of drilling. On May 17, 2010, large formation of gas hydrates similar to ice crystals clogged the dome. On May 26, 2010, the 'top kill' operation was started by BP geared toward stemming the flow of oil "from the MC252 well in the Gulf of Mexico at 1300 CDT." (Gulf, Oil and Gas, 2011) It is reported that the procedure had intentions of stemming the flow of oil and gas and "ultimately [to] kill the well by injecting heavy drilling fluids through the blow-out preventer on the seabed, down into the well." (Gulf, Oil and Gas, 2011 ) In addition, it is reported that BP made the decision to "move the deployment of the Lower Marine Riser Package (LMRP) Cap Containment System." (Gulf, Oil and Gas, 2011) The total of attempts made by BP in the 83 days following the disaster include the following attempts:
During the next 83 days, a series of attempts were made to stop the oil from enter the Gulf of Mexico. These attempts included:
1. Closing the BOP B/S (blind / shear) rams and variable pipe rams with Remotely Operated Vehicle (ROV) intervention (failed).
2. Closing off the end of the drill pipe on the sea floor (succeeded).
3. Capturing oil spewing from the broken riser on the sea floor with a box-like containment device connected to a drilling vessel above (failed).
4. Capturing oil spewing from the riser end with an insertion tube (partially successful).
5. Capturing oil spewing from the BOP top by shearing off the bent over and ruptured riser and drill pipe inside and installing a capture device (called "Top Hat" and Lower Marine Riser Package (LMRP) Cap) (partially successful).
6. Killing the well by injecting heavy mud into the BOP. Flow at the Top Hat still persisted and partial oil capture continued afterward…