NEW ORLEANS (CN) - After spending a week on how BP tried to seal the Macondo Prospect after the well broke in 2010, the trial today turns to the total amount of oil spilled.
Concluding the second phase of a three-part trial, the Department of Justice and BP will each argue their case for how much oil ultimately made its way into the Gulf of Mexico.
U.S. District Judge Carl Barbier is presiding over the federal litigation without a jury.
Attorneys for BP say the well took almost three months to cap because BP and others involved had to contend with many potentially hazardous unknowns.
Iain Adams, an expert for the oil giant, told the court Thursday that, "very often, it's the unknowns that drive your project forward rather than the knowns."
This testimony echoed the sentiment that drove much of the proceedings during the first week of trial.
BP says that it was gathering oil-flow estimates from the beginning, but that these estimates were largely worst-case scenario and inaccurate because it did not known enough of the conditions influencing flow rate, such as the size of the hole in the well, as well as pressure and temperature.
By contrast, plaintiffs say the well took so long to cap because BP was unprepared or worse. They also accuse BP of hiding oil-flow-rate estimates, offering government officials only the very lowest figure obtained, 5,000 barrels a day, simply because the oil giant got caught in its own lie.
Once 5,000 barrels per day was given as the company's "best guess" estimate, BP had to attempt the "Top Kill" method to cap the well despite its knowledge Top Kill would fail if the flow rate was too high, the plaintiffs say. They claim that this was surely the case since calculations in BP's internal emails place the flow rate somewhere around 20 times the figure given to the government.
Adams, managing director of the Norwell drilling company, testified Thursday that BP's attempt at clogging the well with debris as part of the "junk shot" component of the Top Kill had the potential to work no matter how many barrels per day were gushing from the well.
BP eventually discarded its plan to place another blowout preventer atop the failed one from the Deepwater Horizon drilling rig, but the plan could not have worked any earlier than the Top Kill, Adams added. Sealing the well with a capping stack, as was finally done on July 15, 2010, was BP's best bet, he said.
Dr. Adam Ballard, a BP employee who helped with source control during the oil spill, also testified last week. He said that, with regard to gauging flow rate through hydraulic modeling, "there was definitely some information known to some extent, but due to the uncertainties and the things that you didn't know, hydraulic modeling could tell you the most that [the well] could flow, but couldn't inform you anywhere from zero to that range using hydraulic modeling alone."
Ballard told the court Wednesday that the 5,000 barrel per day estimate BP used actually came from the National Oceanic and Atmospheric Administration.
He said the purpose of the hydraulic modeling in which he had a hand during the oil spill was not to assess flow rate.