By Phaedra Friend Troy
In the deepwaters of the Gulf of Mexico, BP has begun flushing the Macondo subsea equipment in preparation for the ambient pressure testing procedure.
For comprehensive coverage of the Deepwater Horizon incident, oil spill in the Gulf of Mexico and efforts under way to resolve them, visit PennEnergy's Oil Spill in the Gulf of Mexico special section.
With the approval of the Unified Area Command, BP has started flushing the drilling mud and hydrocarbons from the sealing cap and the original Deepwater Horizon lower marine riser package and blowout preventer (BOP).
The flushing will ready the equipment for the pressure test procedure that will help the oil spill team to determine the state of the BOP and sealing cap under ambient conditions.
Starting on the afternoon of Aug. 18, the flushing procedure involves attaching a drill string to the top of the existing sealing cap. Then the middle blind shears of the sealing cap will be opened.
Next, the Q4000 will pump an anti-freeze mixture into the existing manifold, which will travel into the BOP choke and kill lines. The mixture will then be flushed from the equipment through the drill string to the Discoverer Enterprise on the water’s surface.
Finally, the sealing cap’s blind shear ram will be closed again following the flushing procedure.
Following a successful flushing, BP will begin a 48-hour ambient pressure test to make sure the well is completely secure before the bottom kill can begin. The test time is twice the estimated time it will take to remove the original BOP and replace it with the Transocean Development Driller II BOP.
In preparation from the procedure, a storm packer is being placed in the second relief well, and the Development Driller II is preparing its BOP for use on the Macondo well.
The runaway Macondo well has been completely shut-in since July 15, when the three ram capping stack was successfully installed on the deepwater well. Since then, the well has been cemented via a top kill procedure.
The bottom kill procedure, performed when the first relief well intercepts and cements the well, will permanently and finally seal the Mississippi Canyon oil and gas well from leaking any hydrocarbons into the Gulf of Mexico.
The oil spill began on April 20, when a blowout occurred aboard the Deepwater Horizon drilling rig while it was plugging the Macondo discovery well. The blowout caused an explosion aboard the rig that took the life of 11 crewmembers and cause the semisubmersible to sink to the ocean floor.
BP starts flushing Macondo subsea equipment in preparation for bottom kill
By Phaedra Friend Troy