BP encouraged by integrity test results on Macondo well in gulf

Paula Dittrick
OGJ Senior Staff Writer
HOUSTON, July 17 – BP PLC reported a pressure reading of 6,745 psi within the top of the Macondo well early July 17, prompting a spokesman to say he was encouraged so far although he cautioned that no conclusions could be reached while the test was continuing.

Kent Wells, BP senior vice-president, of exploration and production, said the integrity test might be extended beyond its initial 48-hr period, which would end at 2:25 p.m. on July 17.

“There are no indicators of lack of integrity,” Wells said, noting extensive monitoring is ongoing for any signs that the wellbore is leaking oil or gas. “The longer the test goes, the more confidence we have in it.”

Wells noted some bubbles coming from a valve, adding he expected this was a normal sign of well construction rather than of hydrocarbons leaking. He said those bubbles would be tested as a precaution. He said bubbles sometimes come from other wells, and it's not ordinarily an indicator of a well integrity problem.

National Incident Commander and retired Adm. Thad Allen will make the decision when to end the test based on consultations with BP, industry experts, and other scientists. On July 16, Allen said models done in preparation for the test had indicated that 7,500 psi or higher would indicate well integrity.

Wells said 6,745 psi was within a reasonable range of 7,500 psi to demonstrate well integrity. He noted the pressure was building at about 2 psi/hr, adding that he expected it to top out at 6,800 psi with a margin-of-error factor of about 50 psi either way.

Allen said current pressure readings could indicate two different possibilities. “One of them could be the pressure is lower because we have depleted the reservoir based on the amount of oil that’s been produced and really sent to the environment,” Allen said. “Alternatively, it could mean that there is a loss of products some place in the wellhead…because of well integrity [problems]. And, there are plausible supporting arguments for both of those.”

Consequently, Allen asked BP for enhanced surveillance including acoustic monitoring and temperature readings around the wellhead as well as more seismic surveys “that will give us a better cross section to understand whether or not there are any anomalies down in the formation that could be resulting from oil leaving the wellbore.”

Additionally, a National Oceanic and Atmospheric Administration vessel was expected to be brought into the area to monitor for methane on the surface of the water, Allen said. BP said engineers were working to assure no interference between the frequency at which the NOAA vessel does its work and the frequencies being used by remotely operated vessels already on the seabed.

“You need to be careful not to do any harm or create a situation that cannot be reversed,” Allen said. “We don't know the exact condition of the wellbore. So, the discussion is centered around why it is at 6,700 and going up slowly.”

Allen described the ongoing decision process as “conditioned based” with ongoing discussion every 6 hr about the best ways to measure well depletion and a focus on what factors could play a role in well depletion pressures.

“It's a very, very good thing that the well has been shut in right now,” Allen said. “There's no oil being released in the environment…. I would remind everybody that the purpose of the cap and where we're going has always been containment, and the final solution was going to be the relief well.”

Contact Paula Dittrick at [email protected]