Allen said the ambient pressure testing would take approximately 48 hours (i.e. ending August 21) and if there are no anomalies and no hydrocarbons present, then they would conduct what is being called a "fishing experiment." He said, "We are going to actually put a drill bit down in the blow out preventer and attempt to extract the drill pipe. The reason we want to try and extract the drill pipe that reduces the risk that when we remove the blow out preventer and put the new one on, there won't be an (off score) or some kind of a bar to having a seal with the new blow out preventer. And we have told BP you need to do the ambient test, conduct the fishing experiment, come back to us with the results and then we will proceed after that. . ."
Allen said all of the operations have been done with an "overabundance of caution related to minimizing risk associated with the intersection of the well." He said, "We are very, very close to the end. This gets to be a very, very complex evolution and there are no black and white choices here and this has required a significant amount of discussion. . . At the press brief yesterday someone asked about a timeline, I said there was no timeline at the present and that was true. There remains a sequence of events that will be carried out. They are conditions based. When we take one step and we are successful, we will move to the next step. Should all these steps prove successful and we move towards the eventual intersection of the well, that could take place sometime the week after Labor Day.
The researchers measured distinguishing petroleum hydrocarbons in the plume and, using them as an investigative tool, determined that the source of the plume could not have been natural oil seeps but had to have come from the blown out well. Moreover, they reported that deep-sea microbes were degrading the plume relatively slowly, and that it was possible that the plume had and will persist for some time.
The WHOI team based its findings on some 57,000 discrete chemical analyses measured in real time during a June 19-28 scientific cruise aboard the R/V Endeavor, which is owned by the National Science Foundation (NSF) and operated by the University of Rhode Island. They accomplished their feat using two highly advanced technologies: the autonomous underwater vehicle (AUV) Sentry and a type of underwater mass spectrometer known as TETHYS (Tethered Yearlong Spectrometer). Richard Camilli of WHOI's Applied Ocean Physics and Engineering Department, chief scientist of the cruise and lead author of the paper said, "We've shown conclusively not only that a plume exists, but also defined its origin and near-field structure. Until now, these have been treated as a theoretical matter in the literature."