(story updated: well integrity test extended into July 20; adding seepage details)
OGJ Senior Staff Writer
HOUSTON, July 19 -- BP PLC, operator of the Macondo well, reported that the well integrity test continued July 19 with pressure readings inside the well at 6,792 psi and continuing to rise slowly. A federal spokesman reported a seep was detected near the well.
During the test, a three-ram capping stack has been closed, shutting in the well. Test results and monitoring activities will determine whether to return to using the oil and gas collection systems. If the collection systems are to be restarted, there would be some leakage again of oil and gas into the Gulf of Mexico, possibly for a number of days, BP and response officials agree.
An Apr. 20 blowout of the Macondo well caused an explosion and fire on Transocean Ltd.'s Deepwater Horizon semisubmersible, killing 11 crew members and resulting in an oil spill. The integrity test started July 15, marking the first time since April that the well has not leaked oil and gas into the gulf.
National Incident Commander and retired Coast Guard Adm. Thad Allen said on July 19 that he had authorized the integrity test to be extended into July 20. He said one methane seep was observed 3 km from the well, but industry experts doubted that it was associated with Macondo. Other small seeps briefly were observed in the range of 80-200 m of the wellhead on July 18.
"There is some natural seepage out there of both oil and gas," Allen said. He reported other "anomalies" including gas bubbles around the sealing cap and also formation of gas hydrates being caused by a leak in a metal gasket in a flange.
Previously, Allen sent BP a letter on July 18 stating “that there were a number of unanswered questions about the monitoring systems they committed to as a condition of the US government extending the well integrity test.” BP cancelled a technical briefing with reporters scheduled for early July 19.
Late July 18, members of a federal science team had a conference call with BP representatives “to discuss some specific issues, including the detection of a seep near the well and the possible observation of methane over the well,” Allen said.
Allen said ongoing monitoring and full analysis of the seepage continues in coordination with the science team.
“I authorized BP to continue the integrity test for another 24 hours, and I restated our firm position that this test will only continue if they continue to meet their obligations to rigorously monitor for any signs that this test could worsen the overall situation,” Allen said. “At any moment, we have the ability to return to the safe containment of the oil on the surface until the time the relief well is completed and the well is permanently killed."
Relief well makes progress
The first relief well reached 17,864 ft measured depth as of July 18, and the next operation is a ranging run as the relief well has approached its last casing end point. Following casing set, additional ranging runs will be used to guide the drill bit to an intercept point with the Macondo well.
After interception, operations are expected to begin to kill the flow of oil and gas from the reservoir by pumping specialized heavy fluids down the relief well.
Drilling of a second relief well, which started May 16, have been paused at 15,874 ft measured depth so as not to interfere with the ranging runs being performed in the first relief well.
Although uncertainty remains, the first half of August remains the current estimate of the most likely date by which the first relief well will be completed and kill operations performed.
Plans continue for building and installing additional containment capacity to increase recoverable oil volumes to 60,000-80,000 b/d. BP has said these additional systems also will enable vessels to disconnect and reconnect faster in case a hurricane reaches the gulf.
Collection systems involving the Helix Q4000 multiservice vessel and the Helix Producer floating production unit, were suspended for the test, which started on July 15.
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