Solution (without nuclear bomb) to the hydrocarbon leak following the accident on the offshore Deep Water Horizon platform of BP (Gulf of Mexico)
Looking for a solution
June 30, 2010 - July 5, 2010
The cause of the catastrophe that occurred 60 kilometers off the coast of Louisiana, on the offshore Deep Water Horizon platform, was a blow out, a sudden rise of hydrocarbons during the drilling of a well on the ocean floor. A simple look at Wikipedia shows that many land and underwater platforms have experienced this sudden eruption during drilling.
A BOP (blow out preventer) is usually installed on all well heads, and allows immediate blocking of the drilling tube simply by crushing it, which in principle allows to contain pressure rises ranging from 300 to 1000 bars.
**An Italian blow out preventer system, installed on drilling heads. **
The following photo gives an idea of the object's dimensions:
A blow out preventer
On the net, an animation shows the operation of a battery of two units, working by cutting the drilling tube.
A battery of two blow out preventers, squeezing the drilling tube
**The same, after cutting the tube in two places. **
These devices can be activated either from the platform by the staff, or automatically, from acoustic sensors located near the well head and which detect a sudden pressure rise, linked to the fact that the drill bit suddenly opens on a cavity filled with hydrocarbons under high pressure, regardless of the source of this pressure. At ten kilometers depth, this pressure can be tectonic, related to the moment of the plates. I read in some papers published online that for Deep Water Horizon, the drilling depth was 5000 meters.
For a reason that may never be clarified, unless some staff members reveal the truth, BP had decided to stick to the manual control system, from the platform. A blow out occurred, which sent a huge bubble of methane to the surface, which caught fire at the surface, immediately igniting the platform, killing eleven workers and injuring 17 others. In the middle of this ocean of fire, it was impossible to activate the BOPs. The fire spread to the entire platform, which continued to burn, had to be evacuated in a panic and sank two days later.
Robert Kennedy Jr, an environmental lawyer, published an article dated May 10, 2010 on the Huffington Post where he makes serious accusations against the company that managed this drilling. According to him, this acoustic signal activation device is necessarily required on the oil platforms of many countries. But when the Bush administration took over the American state, under the intervention of Dick Cheney, the offshore oil drilling companies were exempted from installing this device, which costs relatively little, 500,000 dollars (cost of half a day's work on an offshore platform). According to Robert Kennedy Jr, the American administration would be the seat of systematic corruption, granting permits and exemptions to the highest bidders.
Let's take a short break to explain the basic principles of oil drilling.
Below is how a land derrick works.
The derrick operates a drill bit, often equipped with three rotating cutters.
A drill bit (somewhat worn). In the center, the injection hole for the drilling mud
The drilling pipes have a standardized length (30 feet, or a little more than nine meters). The reserve tubes are usually placed against the derrick. They are put in place one after another by screwing them together, according to a standard thread. The last tube placed is connected at its upper part to a solid "square pipe" which is enclosed in a rotating table, itself rotated by a motor. When a new drilling pipe has been driven in, the movement is stopped. The pipe is disconnected from the square pipe, which is raised. A new pipe is positioned, screwed and connected at its upper part to the square pipe. Then the square pipe is again enclosed in the rotating table, and the motor is restarted. The drilling resumes.
It can be seen that a drilling operation at a depth of one thousand meters in the rock involves one hundred drilling pipes. If the Deep Water Horizon drilling was at 5000 meters and the operation lasted 78 days, that is 7 pipes per day.
The diameter of the drilling, determined by the cutting diameter of the drill bit, is larger than the diameter of the drilling pipe, which leaves a space between it and the hole drilled in the rock or sediments, the interstices allowing the rise of cuttings and the installation of a "casing," a "tubing," in contact with the rock by concrete.
The drill bit needs to be cooled. This cooling is done using a liquid that is injected under pressure through the drilling pipe, and which rises along its periphery, carrying with it the rock cuttings. In oil drilling, a special drilling mud is used, based on clay and polymers, which has both lubricating and thixotropic properties. This mud has the property of maintaining its fluidity if it is kept in motion, and of taking on a solid appearance if the movement stops. Thus, when drilling is stopped, this substance remains in place. Without this essential property, it would be impossible to perform excavations. When drilling resumes, the drilling mud regains its fluidity.
This is exactly the property of quick sand, which can be found in estuaries, like that of Bénodet, in Brittany. I say this because when I was eleven years old and was at a scout camp, I almost disappeared in such a thing, and if I hadn't been carrying a pine branch with me, I wouldn't be here to tell you about it.
At low tide, I was walking on this dark mud, which seemed compact, when suddenly I sank all at once up to my waist. The impact of my step was enough to cause an immediate phase change. But because of my immobility, this thixotropic mud immediately regained its solid appearance, firmly holding half of my body. I thought and used my tree branch as a support to get out of this trap. But it wasn't an easy task, I assure you.
The classic component of the drilling mud is bentonite, which is based on clay, with a density of around 1.8. This density plays a key role in preventing the rise of hydrocarbons, *by simple hydrostatic pressure effect. *
Ten meters of water = 1 atmosphere, or 1 bar
Ten meters of bentonite: 1.8 atmospheres, 1.8 kilograms per square centimeter.
Take the case of the offshore drilling on the Deep Water platform. It is 1500 or 1600 meters above the seabed. If we add this depth and the (alleged) drilling depth, we get 6600 meters, which corresponds to a drilling mud pressure of 1188 bars at the drill bit. This pressure prevents hydrocarbons from rising up to the platform, on the surface. This pressure drops to 660...