Irrigation pump numbers illustrate under-reporting by BP and U.S. govt.
A 4-inch pipe on a tractor PTO-powered pump can crank out around 35,000 barrel-equivalents per day. Considering the length of the Gulf oil gusher pipe, and the viscosity of the oil, an expert shows that the Coast Guard’s number for the reservoir pressure of 8-9,000 psi is far too low.
We all know that BP and the U.S. government have been low-balling the numbers for just how much oil is spewing from BP’s Gulf oil disaster. Doing doing a comparison to the irrigation pump industry can help show how dishonest they are being. At least so I thought until I called a professor from a local university, who ran some numbers for me and also explained the variables involved.
Paul Noel sent me a link today to http://gator-pump.com/specs.htm which shows how much water can be pumped by the various sizes of irrigation pumps they sell. According to Dale Lemmons, VP of Gator Pump, Inc., who I spoke with today, their numbers are all engineer tested and certified. They’ve been in business for 33 years.
According to the specs overview sheet, their smallest pump, the Sunfish, with just a 4 inch pipe, pumps 1150 gallons per minute (gpm) with 35 feet of head (uphill), using a 540 revolution per minute power takeoff from a tractor. (Note, the numbers for flow vary depending on head, horsepower, and rotation speed of the PTO.)
Here’s the math. 1150 gallons per minute x 60 minutes per hour x 24 hours per day = 1,656,000 gallons per day. Divide that by 42 gallons per barrel (of oil) = 39,429 barrels of water per day. That’s for their smallest pump.
That’s close to the biggest numbers that have been published for the Gulf oil gusher rate of flow by the mainstream press, who tend to play lapdog for the corrupt powers that be.
According to BP, the gusher pipe has a diameter of 21 inches.
Now let’s apply the same math for the largest irrigation pump that Gator Pump, Inc. sells. According to the specs overview sheet, their Whale, which has a 24-inch diameter — three inches larger than the BP gusher pipe — pumps 17,000 gallons per minute (gpm) with 15 feet of head (uphill), using a 540 revolution per minute power takeoff from a tractor. 17,000 x 60 x 24 / 42 = 582,857 barrels per day. That’s twice the amount of the Exxon-Valdeez spill every single day.
Seeing that, I was curious to know the pressure behind this irrigation pump. That was when I called and talked to Dale Lemmons, who said the pressure in the Whale pump was measured by the Engineers at 10 psi.
Here’s the Engineering report for the Whale irrigation pump.
(See at link)
There are some important differences between the scenario of an irrigation pump being powered by a tractor, and an under-sea oil gusher powered by tremendous pressures. We’ve heard numbers in the range of 20,000 to 50,000 psi for the oil gusher, but as is to be expected, the mainstream press shows numbers much smaller. An interview that Alex Jones had with Lindsey Williams today gave that range of numbers as well, his sources including a former oil CEO as well as some BP personnel.
According to an ABC News interview with US Coast Guard Admiral Thad Allen, published today, Allen said that the pressure down at the gusher is estimated at between 8 and 9,000 psi.
TAPPER: What is the wellhead pressure, do we know?
ALLEN: Ah, well, we haven’t tested it in a while, I can tell you during the “Top Hat” evolution – let me start at the reservoir, down at the reservoir where the well was drilled to varied somewhere between 8-9,000 PSI, pounds per square inch. During the Top Kill evolution, I think at the bottom of the blowout preventer, somewhere around 3500 PSI.
TAPPER: Is it possible that it is worse than that?
ALLEN: We won’t know. In fact that’s the reason we need the pressure readings.
TAPPER: Are there thresholds impossible to control — that would be above 20,000 PSI example?
ALLEN: Yeah, there are thresholds at even the well bore can’t contain that kind of pressure. One of the reasons we didn’t move to cap the well completely after the Top Kill failed was we didn’t know what the condition of the well board was. If you keep jamming mud down there, or you cap it completely, put pressure back down the well bore, the one thing you don’t want to do is have hydrocarbons or oil get outside the well or into what we call the formation or the strata and somehow make its way to the surface, where you would have an uncontrollable leak at that point. You want to guard against that at all costs.
According to the local professor of Mechanical Engineering, and an expert in fluid dynamics, the primary driver for flow rate is the pressure difference between the reservoir and where the fluid emerges. Pipe length, bends, fluid viscosity, density, and temperature also all play a determining role, in addition to the diameter of the pipe and of the opening.
For his calculations, he used the following information:
Reservoir pressure = 8,000 psi
Pressure at rupture = 3,500 psi
Elevation from well to rupture = 25,000 ft [this is the primary point of friction]
Pipe diameter = 21 in.
Density of crude = 840 kg/m^3
Viscosity = 2-4 Pa-s [viscosity and density using Azeri crude as typical, according to BP’s website (density is addressed on page 3; see near the bottom of page 5 for viscosity)]
Temperature 1 mile down: “Almost all of the deep ocean temperatures are only a little warmer than freezing (39°F).” (savethesea.org)
Here is what he wrote in response:
Based on the numbers you gave me the pressure in the reservoir is insufficient to overcome the hydrostatic head and there is no flow.
Obviously there is something wrong with this because we know that there is a lot of flow and this means the value of 8,000 psi in the well is too low. All other numbers seem to make pretty good sense.
Using a value of 20,000 psi in the reservoir I estimate, based on accepted analysis, a flow rate of nominally 65,000 barrels/day. This assumes a straight pipe and oil at nominally 40 deg. F.
If the pressure in the well is as high as 70,000 (this seems very very unlikely), I estimate the flow rate at nominally 185,000 barrels/day.
The pressure in the well is the most important parameter. As you can see, the estimates very significantly based on best estimates for the well pressure.
Without a better estimate for the well pressure than we have, I don’t think it is possible to do better than this.
65,000 barrels a day seems to be in line with reports I have seen.
If you have a better estimate on the well pressure I can update my analysis.
One thing that is clear from this expert’s analysis is that the reservoir pressure of 8,000 psi as stated by the Coast Guard admiral is obviously incorrect, being far to low to push oil through that long of a pipe; and the numbers being cited from non-mainstream media sources, in the range of 20,000 to 70,000 psi are much more likely for producing the volume of oil that we’re seeing in the Gulf.
The measured pressure of the producing formation is about 11,800. The measured back pressure at the BOP prior to cutting off the riser was about 8,300 at sea floor level. After cutting off the riser kink the pressure at the BOP dropped to about 4,400.
One thing you can’t and won’t know is how big is the orifice or cross sectional area thru the BOP and the pinched riser pipe. Hence the BOP back pressure reduction.
I remember way back shortly after this started that the hole size for 5,000 barrels per day at the above mentioned 8,300 psi was 1/4”. That flow path is continuously being eroded by sand and is much bigger, hence the higher flow rates of today. The bigger the hole gets cut out by sand the higher the flow rates but with a reduction in back pressure.
The weight of the mud was in an email...could have been fabricated ...
Odd the MSM isn't able to "catch" the under-reporting by BP and the Coast Guard. It seems simple enough - do what you did Irisshlass: Go to an engineer and ask a few questions...