We're going to be calculating flow for a well, guessing a few variables, which I'll explain are guesses. This math is from Production Optimization Using Nodal Analysis by H Dale Beggs, c. 1991.
Assumptions
The well is a saturated reservoir - This means there is no gas cap and that oil is saturated with oil, providing additional lift. I feel that initial reservoir conditions, this is a safe assumption.
The well has been continuously accessing new reservoir without reaching a fault or boundary - This is a very unlikely assumption, but makes my math a lot easier, as it assumes a steady-state flow. The well probably reached a boundary and saw an associated decrease in flow of almost 1/2 in the first week, which decreased again at the next boundary, etc.
Flow is in a bubble flow state - Again, this is a safe assumption in a newly tapped saturated reservoir.
Variables
d - pipe diameter, which I'm going to say is 3" pipe (2.441" ID) which is an ID of 0.0620014 m
mu- viscosity, which I'm guessing is 0.05 kg/m-sec, and this is a wild-ass guess, but in the dense oil range.
rho - density, which I'm guessing is 1000 kg/m^3, which is again, a wild-ass guess, but in the dense oil range.
Pres - the reservoir pressure. Again, we throw out a number, say... 18,000 psi. This is proprietary knowledge like the last two data points and is also a wild-ass scientific guess. If you have a better number, please plug it in and redo the math.Actually if anyone can supply *any* of these numbers, please do so.
Pout - the pressure at the end of the pipe. 5000 ft of water is about 2884 psi of back pressure.
delta_P - the pressure drop between reservoir and fluid release from the pipe. Based on the above, 15, 116 psi, which is 104, 221 kPa.
V - velocity of flow (m/s)
f - dimensionless friction, and this is where I'm really going to cheat. I'm calling f = 0.004 based on 3-inch new steel based on a table lookup
L - pipe length, approximately 13,000 ft is 3962.4 meters
with an diameter of 0.0620014 m, the area is 0.049m^2, and the flow is 0.044 m^3 per second.
This is 0.276751674 bbl/s, and there are 86,400 seconds per day.
This is approximately 23,907bbl/day of oil.
So there is a quick, back of the envelope guess of the immediate flow from the reservoir, based on many guesses. Concerns about the environment are left as an exercise to the reader.
The problem is: Who pays for the domes? Remember, a drilling project like this can easily cost a million US dollars/day. I'm betting rental on this unit (oil equipment is always rented, never sold) runs several thousand if not hundred thousand a day. While on one hand, you might say "at a million dollars a day what's a few hundred thousand" the other hand says "I'm already paying a million a day, why do you want to make me pay 1.1 million to protect against an event that happens less than once per year?"
IAA(non-certified)PE, although I don't work for any of the companies in question.
Although drilling is a cowboy science, there are a few concepts to it that are not immediately obvious and help explain what they're doing. I'd like to define the problem a little bit better, which may actually lead to someone finding a better answer.
The problem that they're facing is that there is a pipe placed in a hole down many thousand feet into an oil reservoir, most likely at the edge of a salt dome. The reservoir is at very high pressure (which is common in the GoM and one of the benifits of drilling here), and effectively we have an uncapped fire hydrant spewing high pressure fluid into the ocean, which floats up and producing the lovely oil sheen. As you'll notice, all attacks follow this vein... capping the end of a wildly spewing fire hydrant. My personal opinion isn't really relevant, but hey, they've got to show they're trying all options.
During drilling we control well pressures during drilling with heavy mud fluids, which provide counter-pressure and keep this problem in check. From a discussion on a plane yesterday with someone in well completions, they had set a plug in the drilling fluid (probably a brine at this point, replacing the mud) but may not have tested it well enough, and enough gas escaped from below the plug to displace the drilling fluid with a large bubble of gas. The low density of the gas created an unstable pressure system, and allowed the pressure below to burst through the plug and cause a kick, sinking the rig. Note that rigs tend to drill many wells at the same location now, spreading them out using directional drilling but not actually moving the rig. When we drill a well and a production platform is not yet in place, we temporarily cap the well... using the same process that didn't go so great this time. So when the drilling platform sank, any already drilled and capped wells were likely damaged as well. These are likely easier to shut off due to properly operating subsurface safety valves being in place (required in the GoM), and possibly BoP stacks being in place still as well (not likely but maybe? usually these are removed after drilling).
So here we are, with the BoPs not working on this one well, and it's gushing oil. In most situations we drill a relief well, because when we intersect the gushing well, our wellbore is full of drilling mud, and we can kill the flow by using extra-heavy mud weighs to stifle flow right at the source. This is, in my opinion, the best and most complete option. The problem to this method is that it takes days/weeks, not hours/days, and we want an "hours/days" solution. Hence the multi-million-dollar "cork" they are trying to place on top of this fire hydrant. I see estimates of 3 monthsin the news for the relief well being effective, and I think that's a bit high but reasonable. "Off the cuff" (do not use this as a real estimate) I like to guess about 500 feet of drilling a day, and this well is 13,000 feet, but that's certainly much too optimistic in this case.
Here is a link to an event similar to this one near Australia
Having actually been tazered (at a conference), I can tell you that you don't fall to the ground limbs all akimbo. When tazed all of my skeletal muscles froze up as if I had a full body cramp, and I made a controlled fall for the ground. Everyone that was tazed (maybe a sample set of 20?) went to their knees, then down, although admittedly we knew it was coming, just not when. You seem to pull together to the core and sink. I didn't like the feeling of it, but I think I would have maintained enough control in a real scenario to survive a fall to concrete.
Still, I feel that the argument against tazers should not be "this can still hurt you and shouldn't be used," but rather "it's less likely to kill but it still can." The intent, I feel, is to replace use of lethal force with a less-lethal option. At some point the marketing shifted the idea to it being a safe force. I would not like to be tazed if I can help it, but I would still much rather be tazed if I am out of control (from drinking, low blood sugar, rage, etc) than shot. This other option just should not be allowed to replace the steps that would have been taken to control me if a gun was the only alternative.
Dig a little deeper. Mandeep Khera, the Chief Marketing Officer for Cenzic, is Project Lead and Chief Editor for the paper. The only two other humans listed on the project are a "Erin Swanson, Sr. Director, Product and Strategic Marketing" and "Sameer Dixit, Cenzic ClickToSecure Service." If I found the right guy on Linkdn, Sameer is 3 years out of college.
Gentlemen, we can rebuild him.
We can make him stronger... faster... using the latest in prefabrication materials from Home Depot.
He is... the Sixty-Five Dollar Man.
Not all U.S. officers will welcome this, for various reasons. You Brits have taken a great deal more observation in stride over the years, while we Yanks have railed against it.
When our tracking/automated dispatch system was installed on the ambulances, only a few people took serious exception to the system. Mainly it was because they were: a) sneaking the truck out of district and really didn't want dispatch to know where they were, or b) so invested in the district system that they didn't want to see it change.
You'd assume that group "b" had the quieter districts, but that wasn't always true... some people just didn't want things to change because it meant changing their routine.
When the system was in place, many of us frankly distrusted dispatch. We would be sent halfway across our districts to a call that passed 3 stations, and since we no longer called in our positions, we'd just have to assume that those 3 ambulances were somewhere else. We'd lost our mental map of all our units, and since (in the past) we'd often "volunteer" our position when we knew we the closest truck, we could only assume this was happening again, but where nobody could catch it. I would have invested much more heavily if I could see a map confirming positions in my unit. Not because I was lazy, but because we'd been a (useful) check on the system before, and we wanted that ability to assist from the field again.
Before everyone starts revving up their Hummers, consider how they reach the estimate of "one billion" or even "one hundred billion" barrels of oil. (yes, IAAPE):
Geologic surveys are conducted using seismic waves to identify rock formations that could contain oil or gas.
Or "we see something that looks like a piñata."
Next, somebody spends several million dollars to actually drill into the unknown formation to see if there is oil. Hopefully they find oil, sometimes they don't. As technology improves this risk decreases, but it is still much more rare to wildcat then drill known oil-bearing formations.
Or "we have hit the piñata and there was at least some candy in it."
Now the drilling "steps out" to define the full area which geology suggested contained oil. Much more often then not, faulting, stratigraphic pinch-outs, water legs (etc, etc...) will break a massive hydrocarbon-bearing formation into much smaller segments. Only very rarely is the area actually produced as large as geology suggested.
Or "we continued pummeling the piñata. there wasn't as much candy in the arms as in the legs. There's a piece stuck in the neck that's just not worth going after. Let's just eat all the candy that was easy to get."
Although it is interesting news, let's see if it's still as exciting after a few years of production. Oil fields are like recessions... we get really excited about them up front, but the really great ones can only be identified over time.
Slashdot Mirror
Stand back! I'm going to try Science!!!
We're going to be calculating flow for a well, guessing a few variables, which I'll explain are guesses. This math is from Production Optimization Using Nodal Analysis by H Dale Beggs, c. 1991.
Assumptions
The well is a saturated reservoir - This means there is no gas cap and that oil is saturated with oil, providing additional lift. I feel that initial reservoir conditions, this is a safe assumption.
The well has been continuously accessing new reservoir without reaching a fault or boundary - This is a very unlikely assumption, but makes my math a lot easier, as it assumes a steady-state flow. The well probably reached a boundary and saw an associated decrease in flow of almost 1/2 in the first week, which decreased again at the next boundary, etc.
Flow is in a bubble flow state - Again, this is a safe assumption in a newly tapped saturated reservoir.
Variables
d - pipe diameter, which I'm going to say is 3" pipe (2.441" ID) which is an ID of 0.0620014 m
mu- viscosity, which I'm guessing is 0.05 kg/m-sec, and this is a wild-ass guess, but in the dense oil range.
rho - density, which I'm guessing is 1000 kg/m^3, which is again, a wild-ass guess, but in the dense oil range.
Pres - the reservoir pressure. Again, we throw out a number, say... 18,000 psi. This is proprietary knowledge like the last two data points and is also a wild-ass scientific guess. If you have a better number, please plug it in and redo the math.Actually if anyone can supply *any* of these numbers, please do so.
Pout - the pressure at the end of the pipe. 5000 ft of water is about 2884 psi of back pressure.
delta_P - the pressure drop between reservoir and fluid release from the pipe. Based on the above, 15, 116 psi, which is 104, 221 kPa.
V - velocity of flow (m/s)
f - dimensionless friction, and this is where I'm really going to cheat. I'm calling f = 0.004 based on 3-inch new steel based on a table lookup
L - pipe length, approximately 13,000 ft is 3962.4 meters
Equations
delta_p = (f rho V^2 L)/(2 gc d)
Actual Work
104,221 kPa = 104,221 N/m^2 = (f rho V^2 L)/(2 gc d)
104,221 N/m^2 = ((0.004) (1000)(V^2)(3962.4))/((2) (1) (0.0620014))
104,221 = 127,816 V^2
V^2 = 0.8154 m^2/s^2
V = 0.903 m/s
with an diameter of 0.0620014 m, the area is 0.049m^2, and the flow is 0.044 m^3 per second.
This is 0.276751674 bbl/s, and there are 86,400 seconds per day.
This is approximately 23,907bbl/day of oil.
So there is a quick, back of the envelope guess of the immediate flow from the reservoir, based on many guesses. Concerns about the environment are left as an exercise to the reader.
Parent is incorrect and should be modded down.
The problem is: Who pays for the domes? Remember, a drilling project like this can easily cost a million US dollars/day. I'm betting rental on this unit (oil equipment is always rented, never sold) runs several thousand if not hundred thousand a day. While on one hand, you might say "at a million dollars a day what's a few hundred thousand" the other hand says "I'm already paying a million a day, why do you want to make me pay 1.1 million to protect against an event that happens less than once per year?"
IAA(non-certified)PE, although I don't work for any of the companies in question.
Although drilling is a cowboy science, there are a few concepts to it that are not immediately obvious and help explain what they're doing. I'd like to define the problem a little bit better, which may actually lead to someone finding a better answer.
The problem that they're facing is that there is a pipe placed in a hole down many thousand feet into an oil reservoir, most likely at the edge of a salt dome. The reservoir is at very high pressure (which is common in the GoM and one of the benifits of drilling here), and effectively we have an uncapped fire hydrant spewing high pressure fluid into the ocean, which floats up and producing the lovely oil sheen. As you'll notice, all attacks follow this vein... capping the end of a wildly spewing fire hydrant. My personal opinion isn't really relevant, but hey, they've got to show they're trying all options.
During drilling we control well pressures during drilling with heavy mud fluids, which provide counter-pressure and keep this problem in check. From a discussion on a plane yesterday with someone in well completions, they had set a plug in the drilling fluid (probably a brine at this point, replacing the mud) but may not have tested it well enough, and enough gas escaped from below the plug to displace the drilling fluid with a large bubble of gas. The low density of the gas created an unstable pressure system, and allowed the pressure below to burst through the plug and cause a kick, sinking the rig. Note that rigs tend to drill many wells at the same location now, spreading them out using directional drilling but not actually moving the rig. When we drill a well and a production platform is not yet in place, we temporarily cap the well... using the same process that didn't go so great this time. So when the drilling platform sank, any already drilled and capped wells were likely damaged as well. These are likely easier to shut off due to properly operating subsurface safety valves being in place (required in the GoM), and possibly BoP stacks being in place still as well (not likely but maybe? usually these are removed after drilling).
So here we are, with the BoPs not working on this one well, and it's gushing oil. In most situations we drill a relief well, because when we intersect the gushing well, our wellbore is full of drilling mud, and we can kill the flow by using extra-heavy mud weighs to stifle flow right at the source. This is, in my opinion, the best and most complete option. The problem to this method is that it takes days/weeks, not hours/days, and we want an "hours/days" solution. Hence the multi-million-dollar "cork" they are trying to place on top of this fire hydrant. I see estimates of 3 months in the news for the relief well being effective, and I think that's a bit high but reasonable. "Off the cuff" (do not use this as a real estimate) I like to guess about 500 feet of drilling a day, and this well is 13,000 feet, but that's certainly much too optimistic in this case.
Here is a link to an event similar to this one near Australia
@SquadB Contact Right, Fully Engaged, Send Help lol? Like the MRE pix btw!
Having actually been tazered (at a conference), I can tell you that you don't fall to the ground limbs all akimbo. When tazed all of my skeletal muscles froze up as if I had a full body cramp, and I made a controlled fall for the ground. Everyone that was tazed (maybe a sample set of 20?) went to their knees, then down, although admittedly we knew it was coming, just not when. You seem to pull together to the core and sink. I didn't like the feeling of it, but I think I would have maintained enough control in a real scenario to survive a fall to concrete.
Still, I feel that the argument against tazers should not be "this can still hurt you and shouldn't be used," but rather "it's less likely to kill but it still can." The intent, I feel, is to replace use of lethal force with a less-lethal option. At some point the marketing shifted the idea to it being a safe force. I would not like to be tazed if I can help it, but I would still much rather be tazed if I am out of control (from drinking, low blood sugar, rage, etc) than shot. This other option just should not be allowed to replace the steps that would have been taken to control me if a gun was the only alternative.
"It's not Amway! It's a tiered balloon marketing program!"
Dig a little deeper. Mandeep Khera, the Chief Marketing Officer for Cenzic, is Project Lead and Chief Editor for the paper. The only two other humans listed on the project are a "Erin Swanson, Sr. Director, Product and Strategic Marketing" and "Sameer Dixit, Cenzic ClickToSecure Service." If I found the right guy on Linkdn, Sameer is 3 years out of college.
How is anyone surprised by the resulting paper?
Since nobody drives everywhere in the country...
Truck Drivers. If you can find your way into the CB bands, you'll get a lot of info.
The Earth's population is estimated at 6.789 billion. So statistically, this asteroid is going to kill 27,156 people?
Gentlemen, we can rebuild him. We can make him stronger... faster... using the latest in prefabrication materials from Home Depot. He is... the Sixty-Five Dollar Man.
It's controversial because they're not giving out black badges if you win.
Probably much longer than it took me to come up with Central Opening/Latrine Bathroom Excretion and Removal Tender.
Not all U.S. officers will welcome this, for various reasons. You Brits have taken a great deal more observation in stride over the years, while we Yanks have railed against it.
When our tracking/automated dispatch system was installed on the ambulances, only a few people took serious exception to the system. Mainly it was because they were:
a) sneaking the truck out of district and really didn't want dispatch to know where they were, or
b) so invested in the district system that they didn't want to see it change.
You'd assume that group "b" had the quieter districts, but that wasn't always true... some people just didn't want things to change because it meant changing their routine.
When the system was in place, many of us frankly distrusted dispatch. We would be sent halfway across our districts to a call that passed 3 stations, and since we no longer called in our positions, we'd just have to assume that those 3 ambulances were somewhere else. We'd lost our mental map of all our units, and since (in the past) we'd often "volunteer" our position when we knew we the closest truck, we could only assume this was happening again, but where nobody could catch it. I would have invested much more heavily if I could see a map confirming positions in my unit. Not because I was lazy, but because we'd been a (useful) check on the system before, and we wanted that ability to assist from the field again.
I for one welcome myself as our new tyrannical overlord.
Name it Ash.
I agree, this lawsuit will only trigger the "Barbara Streisand Female Impersonator" Effect.
Somebody should write this shit down.
You need to find a rural service. I used to whittle on duty I was so bored.
Das Reboot.
Why the Air Force?
Because it's cyber-*space*. The army can operate on the LAN(d).
Before everyone starts revving up their Hummers, consider how they reach the estimate of "one billion" or even "one hundred billion" barrels of oil. (yes, IAAPE):
Geologic surveys are conducted using seismic waves to identify rock formations that could contain oil or gas.
Or "we see something that looks like a piñata."
Next, somebody spends several million dollars to actually drill into the unknown formation to see if there is oil. Hopefully they find oil, sometimes they don't. As technology improves this risk decreases, but it is still much more rare to wildcat then drill known oil-bearing formations.
Or "we have hit the piñata and there was at least some candy in it."
Now the drilling "steps out" to define the full area which geology suggested contained oil. Much more often then not, faulting, stratigraphic pinch-outs, water legs (etc, etc...) will break a massive hydrocarbon-bearing formation into much smaller segments. Only very rarely is the area actually produced as large as geology suggested.
Or "we continued pummeling the piñata. there wasn't as much candy in the arms as in the legs. There's a piece stuck in the neck that's just not worth going after. Let's just eat all the candy that was easy to get."
Although it is interesting news, let's see if it's still as exciting after a few years of production. Oil fields are like recessions... we get really excited about them up front, but the really great ones can only be identified over time.