The Gulf Oil Spill Whose to Blame as well as a reflection of the science literacy problem in the US

Deep Water Drilling: The Dangers of High pressure

Geometry of the BOP

How an Oil Well Works The oil entering at the bottom requires an internal pressure source to push it to the top – this is usually supplied by associated gas deposit

Simple Physics ► Without any additional source of pressure oil by itself will not be squeezed up the tube. Thus crude oil without an internal pressure sure is usually a Dry Well ► The deeper you drill the higher the internal pressure you likely to tap. This is why you need a pressure regulator a.k.a The Blow Out Preventer

1. The BOP is located at the bottom of the Gulf of Mexico so there is 5000 feet of water on top of it. The BOP is rated up to 15,000 PSI and is connect to a 21 inch diameter pipe. 2.Deep Reservoir Pressure was estimated by Coast Guard to be 8000 PSI – so no problem in principle 4. Before the accident the BP horizon was producing 15-20,000 barrels a day suggesting pressures of PSI had been tapped, 3. Geological data suggested that average reservoir pressures in these deep marine pockets could be 20,000 – 40,000 psi. 20,000 PSI will give you a flow rate of 50,000 barrels a day for a 21 inch diameter pipe. The initial estimate of 1000 barrels a day was therefore impossibly low. By the way, if you leave your bathtub on for 24 hours the volume flow rate would be equivalent to 500 barrels a day through a 2 inch pipe!

1000 barrels a day, in fact, would be confined easily by 5000 feet of water  so no leakage would occur. In addition, BOPs are rated at 15,000 PSI. The mere fact that it failed tells you the pressure must be at least that Also, a typical deep marine rig will process about 20,000 barrels a day. The fact that BP got away for at least a week by stating a figure of 1000 barrels a day is a sad testimony to the science illiteracy of this country and especially congress!

Flow rate from Velocity Estimates If you don’t know (or pretend not to know) the actual pressure differential there is another method that can be used to estimate the flow rate. The flow velocity comes from video camera measurements only – no one every installed a velocity meter because it was too difficult. Various techniques can be used to estimate the flow velocity from video frame rate data. Those estimates come in at around 1 meter/sec (about 2 mph)

Velocity based flow estimate ► Diameter of pipe is 21 inches  cross section is.2 square meters ► Volume flow rate is then 1 m/sec *.2 =.2 cubic meters per second ►.2 * 3600 seconds per hour = 720 cubic meters per hour = 720,000 liters/hour ► One bbl = 159 liters. Thus 720,000/159 = 4500 barrels/hour (in round numbers) ► 4500 x 24 = 108,000 barrels per day  100 times worse than the initial estimate