BP update: ‘top kill’ halted at 11.59 pm May 27, results under review. If successful, will commence cementing
Source: http://www.bp.com/genericarticle.do?categoryId=2012968&contentId=7062470
Subsea efforts continue to focus on progressing steps to stop the flow of oil from the well through interventions via the failed Deepwater Horizon blow out preventer (BOP), and to collect the flow of oil from the leak points. These efforts are being carried out in conjunction with industry experts and governmental authorities.
Heavy drilling fluids were pumped under pressure into the BOP starting May 26 at 1300CDT and continued through 2400CDT (midnight) on May 27. The heavy fluid pumping was stopped at midnight (11.59pm) May 27 to evaluate the progress. It is estimated that the full top kill procedure could extend for another 24 to 48 hours.
If the well was successfully ‘killed’, it is expected that cementing operations would then follow. The top kill procedure has never before been attempted at these depths and its ultimate success is uncertain.
In parallel with the ongoing top kill operation, preparations have been made for the possible deployment of the lower marine riser package (LMRP) cap containment system. Deployment would first involve removing the damaged riser from the top of the failed BOP to leave a cleanly-cut pipe at the top of the BOP’s LMRP. The cap, a containment device with a sealing grommet, will be connected to a riser from the Discoverer Enterprise drillship, 5,000 feet above on the surface, and placed over the LMRP with the intention of capturing most of the oil and gas flowing from the well.
The LMRP cap is already deployed alongside the BOP in readiness for potential deployment. If it is decided to deploy this option, this would be expected to take some three to four days.
In addition to these steps, planning is being advanced for deploying, if necessary, a second BOP on top of the original failed BOP.
Drilling of two relief wells began on May 2 and May 16. It is estimated that each of these wells will take three months to complete from the commencement of drilling.
