OGJ Senior Staff Writer
HOUSTON, July 15 -- BP PLC started its well integrity test on the Macondo well on Mississippi Canyon Block 252 in the Gulf of Mexico on July 15 following a 24-hr review of test procedures by scientists and an unexpected equipment-related delay caused by a leaking choke line on a three-ram stack.
The three-ram stack on a sealing cap was fully closed to shut in the well at about 2:25 p.m. CDT on July 16, marking the start of the integrity test. Earlier in the day, oil collection systems involving the Helix Q4000 multiservice vessel and the Helix Producer floating production unit were stopped for the test.
National Incident Commander and retired US Coast Guard Adm. Thad Allen said information gathered during the test will be reviewed with government officials, including a federal science team, to determine next steps. The well integrity test was expected to take 6-48 hr.
Allen issued a directive to BP requiring additional seismic testing and monitoring from remotely operated vehicles during the test. He also requested acoustic and temperature monitoring.
Government scientists, industry experts, and BP executives planned to evaluate test findings every 6 hr, Allen said. Information gained through pressure readings was expected to help crews drilling the relief wells determine how much heavy fluid and what weight of fluid to use for the bottom kill, he said.
“The sealing cap system never before has been deployed at these depths or under these conditions, and its efficiency and ability to contain the oil and gas cannot be assured,” BP said. Shortly after the test started, BP reported no oil could be seen coming from the sea floor or from the well in 5,000 ft of water.
BP emphasized that the test was in its very early stages, and it was possible crews might have to open the well and resume oil and gas collection again depending on what pressure readings develop as the test proceeds. Readings of 8,000-9,000 psi after several hours could indicate well integrity.
During the well integrity test, operations on the first relief well were temporarily stopped as a precaution. The relief well being drilled by the Development Driller III was at 17,840 ft.
Kent Wells, BP senior vice-president of exploration and production, said, “We’re only 4 ft away horizontally from the [Macondo] well” so crews stopped drilling the relief well just in case of the possibility of “flow out the backside” of Macondo toward the relief well during the test.
“We don’t believe that’s going to happen, but I think it’s a really good safe precaution to do that,” Wells said. “We’ll be in a position to commence [relief well] drilling and setting the casing as soon as the test is over.”
Operations on the second relief well were suspended at 15,874 ft to ensure that there is no interference with the first relief well.
“The relief wells remain the sole means to permanently seal and isolate the well,” BP said in a news release.
Contact Paula Dittrick at email@example.com.