Podcast

Music/Announcer:  This is a Podcast from the U.S. Department of the Interior.

Ron Tull: In a teleconference Thursday afternoon, the director of the US Geological Survery Dr. Marcia McNutt announced that three of the scientific teams analyzing flow rates have reached updated assessments, based on new data or analysis, of flow rates from BP’s well before the riser was cut on June 3. The following are her opening remarks from today’s teleconference.

Dr. Marcia McNutt: Under the direction of National Incident Commander Admiral Thad Allen, scientists and engineers with the U.S. Geological Survey the Department of Energy, NOAA, along with top experts from universities and research institutions have been working tirelessly to develop scientific information on how much oil is actually being spilled into the Gulf of Mexico -- both before and after the riser was cut on June 3rd.

This information and analysis will help guide efforts to stop the spill and to effectively deal with its impacts on the gulf, its fragile coastal areas, its fish and wildlife.

This is obviously a challenging scientific issue, since the leak is located a mile below the ocean. As a result, we have teams of scientists working on a variety of different methodologies to develop information that will help us determine the flow rate.

Today I want to give you an update on where we stand.

Let me start by addressing the methodologies being used to estimate the flows from the well:

First, a team of federal scientists led by Energy Secretary Steven Chu is analyzing pressure readings from the Blow-Out Preventer stack and the riser to address flow rates and how flow rates may have changed as a result of the riser being cut.

The Department of the Interior and the Department of Energy have directed BP to provide precise differential pressure measurements inside and outside the top hat to allow federal scientists to develop another independent estimate of how much oil is flowing from BP's well.

Second, the riser Flow Rate Technical Group, which Admiral Allen convened and of which I am the lead, is pursuing a number of independent approaches. We provided an initial preliminary estimate on May 27th based on the data and analysis we had conducted to that point, but we were clear that the teams were going to continue to analyze data as it came in to refine and revise their estimates.

The group’s Plume Modeling Team is pursuing the approach of observing video of the oil/gas mixture escaping from the damaged well, using particle image velocimetry analysis to estimate fluid velocity and flow volume.

The Mass Balance Team is using remote sensing data from deployment of Airborne Visible InfraRed Imaging Spectrometer, also known as AVIRIS, and satellite imagery to calculate the amount of oil on the ocean surface on a certain day. The team is correcting the value for oil evaporated, skimmed, burned, and dispersed up to that day and divided that by time to produce an average rate.

The Reservoir Modeling Team is analyzing the geologic formations as well as composition and pressures of the oil, natural gas, and other compounds that are being released. The team is developing a computer model that includes a wide variety of data from the well and the underlying reservoir.

The Nodal Analysis Team is using input from reservoir modeling (including pressure, temperature, fluid composition and properties over time) and pressure and temperature conditions at the leak points on the sea floor. They are also analyzing the geometries of the well, the BOP, and the riser to calculate fluid compositions, properties, and fluxes from both before and after riser removal.

Finally, a team of experts from Woods Hole Oceanographic Institution and assisted by researchers from Johns Hopkins University, University of Georgia and Massachusetts Institute of Technology have used acoustic technologies to measure flow rates after the top-kill attempt ended and before the riser was cut.

As I mentioned, in coming days we will analyze the new data and bring together the various scientific methodologies to develop an updated estimate of how much oil is currently flowing from BP’s leaking oil well in the Gulf of Mexico.

In the meantime, two of the teams from the Flow Rate Technical Group and the Woods Hole team have developed updated estimates of how much oil was flowing into the gulf before the riser was cut on June 3.

The Plume Modeling Team has analyzed new video provided by BP and calculated now, not just lower bound for the flow – which they estimated on May 27 – but now also an upper bound estimate of for the period of time before the riser insertion tube was inserted and before the riser was cut.

Recognizing the limited data available and the small amount of time to process that data, these scientists estimate of the average flow for the leakage prior to the insertion of the riser insertion tube was between the cutting of the riser, 25,000 to 30,000 barrels per day, but could have been as low as 20,000 barrels per day or as high as 40,000 barrels per day.

The Mass Balance Team based on its analysis of observations made on May 27, and they reported as preliminary estimate of 12,000-19,000 barrels per day. They’ve has conducted additional analysis of the data and have updated that estimate to a range 12,600 to 21,500 barrels a day, and those estimates apply before the riser was cut as well.

Meanwhile, the Woods Hole team generated an estimate of the total flow from the period before the riser was cut. This includes not only oil but natural gas, and any condensates, oil, sediments, and produced water. That team’s initial total flow rate estimate is 0.12m3/s to 0.23m3/s from before the riser was cut. This is a preliminary bulk flow estimate.

If we are to assume, as did the video group, that 40 percent of this outflow is oil, these numbers would convert to potentially more than 25,000 barrels a day from that analysis, however this is of course only an estimate based on these numbers and this is a calculation that would have to be checked because the type of technology they used is also sensitive to gas as well as the oil velocities.

Let me emphasize that our scientific analysis is still a work in progress and, as you can tell, from the range of estimates, there is still a significant difference between the lowest possible estimate and the highest possible estimate.

In the coming days, we will be refining our estimates further and also developing an estimate that combines all of these data points and methodologies into a best estimate from after the riser was cut.

Finally, we are posting data on a new website that you can find on the DOE website. And it’s been established by the hard work of many DOE colleagues, so that the general public can look at the same information that our scientists are studying.

Let me conclude by thanking all the scientists who are working so hard on this challenge. Thank you.

Music/Announcer: This has been a Podcast from the U.S. Department of the Interior.