OGJ Senior Staff Writer
HOUSTON, May 24 -- BP PLC worked to optimize collection rates for oil and gas being diverted from spilling into the Gulf of Mexico by a deepwater blowout, and BP executives said they want to keep using the same chemical dispersant to break up the spilled oil.
In related news, the company announced a commitment of as much as $500 million for a 10-year research program studying the effects that a fatal drilling rig accident and spill have upon the gulf’s marine life and coastal environment.
“BP has made a commitment to doing everything we can to lessen the impact of this tragic incident on the people and environment of the Gulf Coast,” said BP Group Chief Executive Tony Hayward.
“We must make every effort to understand that impact,” Hayward said. “This will be a key part of the process of restoration, and for improving the industry response capability for the future. There is an urgent need to ensure that the scientific community has access to the samples and the raw data it needs to begin this work.”
Oil and gas is being collected through a riser insertion tool, which is a 4-in. steel pipe inserted about 5 ft into a 21-in. damaged riser on the seabed. The end of the damaged riser is about 600 ft from the runaway Macondo well on Mississippi Canyon Block 252.
A blowout resulted in a fire and explosion on Transocean Ltd.’s Deepwater Horizon semisubmersible rig on Apr. 20, leaving 11 crew members missing and presumed dead. BP operates the block.
On May 24, BP estimates its oil spill response cost at $760 million, including costs of the spill response, containment, the ongoing drilling of two relief wells, grants to Louisiana, Mississippi, Alabama, and Florida, federal costs, and claims paid to coastal businesses and residents.
“It is too early to quantify other potential costs and liabilities associated with the incident,” BP said.
Meanwhile, most equipment was in place for the “top kill” procedure, which could start May 26, BP executives estimated. Plans call for heavy drilling fluids to be injected into the well to stem the flow of oil and gas in order to kill the well. Cement might be used to seal the well.
“This is a complex operation requiring sophisticated diagnostic work and precise execution,” BP said. “As a result, it involves significant uncertainties and it is not possible to assure its success or to put a definite timescale on its deployment.”
Collection rates vary
Meanwhile, BP reported that its collection rates through the riser insertion tool continue to vary, “primarily due to the flow parameters and physical characteristics within the riser.”
During May 17-23, the oil flow rate from the blown-out well ranged 1,360-3,300 b/d while the natural gas flow rate was 4-17 MMcfd, BP said. The average collection during this period was 2,010 b/d of oil and 10 MMcfd of gas.
The oil is being stored and gas is being flared on Transocean’s Discoverer Enterprise drillship.
The US government appointed a flow-rate technical team to determine the well flow rate. The team includes the scientists from various federal agencies and departments. An earlier estimate of 5,000 b/d being spilled has been questioned.
BP said it continues “to promptly provide” all information necessary to make as accurate an assessment as possible of the flow rate.
BP has said it wants to keep using the same chemical dispersant despite a mandate form the US Environmental Protection Agency to use a less-toxic chemical. Dispersants have been used both on the surface and at the subsea level to help break up the oil so it degrades faster.
Doug Suttles, BP Exploration & Production Inc. chief operating officer, said Corexit 9500 is “the best option for subea application.” He said tests showed Corexit was among the most effective at dispersing the oil.
EPA on May 20 ordered BP to identify an alternate chemical dispersant and to start using it within 3 days of its approval by regulators (OGJ Online, May 24, 2010).
EPA said it wanted the dispersant changed because of concerns about the unknown long-term consequences of using Corexit in large volumes. The dispersants BP used already on are EPA’s approved list, but this oil spill response is the first time dispersants have been used at the seabed.
“Based on the information that is available today, BP continues to believe that Corexit was the best and most appropriate choice at the time when the incident occurred, and that Corexit remains the best option for subsea application,” BP said in a May 20 letter, which was released May 22 by the EPA.
Suttles said BP found five dispersant products that met EPA’s requirements, and that Corexit appears to have fewer long-term effects. He also noted that availability was an issue. BP said it could not find enough available supplies of other chemical dispersants for its immediate needs to fight the oil spill.
More than 1,100 vessels are involved in the response effort, including skimmers, tugs, barges and recovery vessels. Some 22,000 people are involved in the oil spill response effort.
Skimming operations recovered some 243,000 bbl of oily liquid as of May 24. The total length of boom deployed was nearly 2.5 million ft, including over 730,000 ft of sorbent boom.
Contact Paula Dittrick at firstname.lastname@example.org.
BP commits up to $500 million for spill-related research