OGJ Washington Editor
WASHINGTON, DC, June 15 -- US House Energy and Commerce Committee leaders plan to ask BP PLC Chief Executive Tony Hayward about five crucial decisions that apparently were made before the company’s deepwater Gulf of Mexico well blew out on Apr. 20. Hayward will appear before the committee on June 17.
“The committee’s investigation is raising serious questions about the decisions made by BP in the days and hours before the explosion on the Deepwater Horizon,” Henry A. Waxman (D-Calif.), chairman of the full committee, and Bart Stupak (D-Mich.), chairman of the committee’s Oversight and Investigations Subcommittee, said in a June 14 letter to Hayward.
The congressmen noted that 5 days before the explosion, on Apr. 15, BP’s drilling engineer called the Macondo well “a nightmare well,” and that despite difficulties, BP “appears to have made multiple decisions for economic reasons that increased the danger of a catastrophic well failure.”
Waxman and Stupak said, “In several instances, these decisions appear to violate industry guidelines and were made despite warnings from BP’s own personnel and its contractors. In effect, it appears that BP repeatedly chose risky procedures in order to reduce costs and save time and made minimal efforts to contain the added risk.”
The well was significantly behind schedule when the blowout occurred, which apparently create pressure to take short-cuts, they added.
In particular, they said, the committee is focusing on the decision to use a well design with few barriers to gas flow; the failure to use a sufficient number of “centralizers” to prevent channeling during the cement process; the failure to run a cement bond log to evaluate the effectiveness of the cement job; the failure to circulate potentially gas-bearing drilling muds out of the well; and the failure to secure the wellhead with a lockdown sleeve before allowing pressure on the seal from below.
“The common feature of these five decisions is that they posed a trade-off between cost and well safety,” Waxman and Stupak said.
The letter said that on Apr. 19, when BP installed the final section of steel tubing in the well, it lowered a full string of casing from the top of the wellhead to the bottom of the well, instead of hanging a liner from the lower end of the casing already in place and installing a tieback on top of the liner, which would have cost $7-10 million more and taken longer but also would have provided more barriers to the flow of gas up the annular space surrounding the steel tubes.
“A BP plan review prepared in mid-April recommended against the full string of casing because it would create ‘an open annulus to the wellhead’ and make the steel assembly at the wellhead the ‘only barrier’ to gas flow if the cement job failed,” the letter said.
It said that making certain the casing ran down the center of the wellbore was a key challenge as the final casing string was installed since it would be difficult, if not impossible, to displace mud effectively from the narrow side of the annulus if the casing wasn’t centered and the cement job would be inferior.
‘End of story’
It also said that Halliburton, which BP was using as its cementing contractor, warned the producer that the well could have a severe gas flow problem if the final casing string had only 6 centralizers instead of the 21 which Halliburton recommended. BP rejected the advice, according to the letter, and in an Apr. 16 e-mail an official involved in the decision explained: “It will take 10 hr to install them…. I do not like this.” It said that later that day, another official conceded that there were risks from proceeding with a lower number of centralizers, but commented: “Who cares, it’s done, end of story, [we’ll] be fine.”
Waxman and Stupak also said BP’s mid-April plan review predicted cement failure because cement simulations indicated that formation breakdown made a successful cement job appear unlikely.
“Despite this warning and Halliburton's prediction of severe gas flow problems, BP did not run a 9 to 12-hr procedure called a cement bond log to assess the integrity of the cement seal,” their letter continued. “BP had a crew from Schlumberger on the rig on the morning of Apr. 20 for the purpose of running a cement bond log, but they departed after BP told them their services were not needed. An independent expert consulted by the committee called this decision ‘horribly negligent.’”
The letter also noted that exploratory wells such as this one are generally filled with weighted mud during the drilling process, and that the American Petroleum Institute recommends that the mud be fully circulated from the bottom to the top of the well before cementing begins.
“Circulating the mud in the Macondo well could have taken as long as 12 hr, but it would have allowed workers on the rig to test the mud for gas influxes, to safely remove any pockets of gas, and to eliminate debris and condition the mud so as to prevent contamination of the cement,” the letter to Hayward said. “BP decided to forego this safety step and conduct only a partial circulation of the drilling mud before the cement job.”
The letter said because BP elected to use a single casing string, the well had just two barriers to gas flow up the annular space around the final string of casing: the cement at the bottom of the well and the seal at the wellhead on the sea floor. “The decision to use insufficient centralizers created a significant risk that the cement job would channel and fail, while the decision not to run a cement bond log denied BP the opportunity to assess the status of the cement job,” it indicated.
“These decisions would appear to make it crucial to ensure the integrity of the seal assembly that was the remaining barrier against an influx of hydrocarbons,” Waxman and Stupak’s letter continued. “Yet BP did not deploy the casing hanger lockdown sleeve that would have prevented the seal from being blown out from below.”
It described the decisions in more detail and asked that Hayward come to the June 17 hearing prepared to address concerns that the decisions have raised.
As the committee released the letter on June 14, it also posted 23 supporting documents from BP, offshore drilling contractor Transocean Ltd., Halliburton, and Schlumberger at its web site.
Contact Nick Snow at firstname.lastname@example.org.