PrintJune 19, 2010
About Those Relief Wells
Right now, the hopes of the nation rest on the successful drilling of two relief wells aimed at "plug[ging] the damn hole" in the Gulf of Mexico. On Thursday, the House Subcommittee on Oversight and Investigations held a hearing featuring BP's CEO, Tony Hayward. In its invitation to Mr. Hayward, Congressman Bart Stupak wrote:
The Subcommittee anticipates that its members may have questions requiring technical knowledge of the Deepwater Horizon rig operations, well design, and safety measures and, accordingly, we ask that you be accompanied by a BP employee or official with sufficient knowledge to answer these questions under oath.
In the event, the drilling engineer Mr. Hayward brought with him was never even sworn in to give testimony. Yet right now BP is drilling two relief wells that are the only deep-water offshore wells authorized by the government since the imposition of a drilling moratorium instituted at the behest of Interior Secretary Ken Salazar.
The hearing did not accomplish much. It did establish that the actual well design and operation were done by BP managers well below Mr. Hayward's level and that he had no real-time input into the decision-making process. Rep. Henry Waxman even admitted that after reviewing thirty thousand documents, he had to agree that he had not found anyone linking Mr. Hayward to the daily operations of the Deepwater Horizon.
So other than some political grandstanding, what was Mr. Waxman's intent when he signed the invitation to Mr. Hayward? There certainly was a lot of political theater, as one after another, the congressmen expressed surprise that Mr. Hayward would not answer questions that would require him to swear to hearsay evidence, as he was not present when the decisions in question were made. For a body riven with lawyers, the committee seems to be ignorant of some basic principles of the law. But what else ought the public expect from a group who is surprised that Mr. Hayward does not know the details of the minute-by-minute decision-making taking place several layers of management below him when they are notorious for not reading the legislation that they vote on and whose leader is infamous for saying, "We'll have to pass the bill to find out what's in it"?
There are plenty of drilling engineering questions that remain unanswered. Here are a few.
- Who are the drilling engineers for the two relief wells? What are their qualifications? What standards are they following in their design of the well -- BP's, or those of another company (e.g. Exxon-Mobil)?
- Who is the regulator from the Minerals Management Service approving the relief well design? Might it be Frank Patton, who approved the casing design that failed? Since Elizabeth Birnbaum resigned, there has been no testimony from MMS before Congress, a failure of curiosity that was briefly noted by a few Republican congressmen during the hearing. The situation has taken an interesting turn, with Energy Secretary Chu alleged to have made the decision to stop the "top kill" effort. He does have a Nobel Prize for Physics, but what does particle physics have to do with drilling engineering? Isn't the government expertise in drilling supposed to reside in the Interior Department and its Materials Management Service?
Speaking of the "top kill," the purpose of the relief wells is to do a "bottom kill." The process is conceptually very similar to a top kill, except the heavy drilling mud will be injected into the original well from the bottom rather than the top. To do this, the relief well is being drilled down on a slant to intersect with the existing well. Given all the concern the congressmen had about the number of centralizers used by BP (six instead of the 31 recommended by the cementing contractor Halliburton -- see the Production Casing Design Reports) in a rather vertical well, one would think they would be especially concerned about the number used in a non-vertical well, where the issue will be even more acute.
In its hearing with the chairmen of BP's competitors in the oil industry, the Energy Committee heard that they would operate their wells differently from how BP operated its Macondo Well. Control of the drilling mud is a huge issue in the safe operation of a well. Measuring the flow rate of mud down into the well (through the kill line) and comparing it to the flow back out of the well (through the choke line) is one means of detecting the intrusion of oil or gas into the well.
It was BP's failure to act to kill the well when its return flow began to exceed its flow down hole that elicited the criticism of the other companies. It was that unobserved intrusion of gas into the well that caused the blowout and explosion that killed eleven men and which has wrought such havoc in the Gulf. But the whole purpose of the relief well is to create an imbalance in the flow rates in the relief well while drilling mud flows out of it and into the original well. While mud is rising in the old well, it will be leaking out of the relief well at an immeasurable rate. Whoever is the drilling engineer on the day they break through into the old well will really earn his money that day. Why don't we know who he is?
