The Deepwater Horizon disaster it is one of the largest environmental tragedies in recent history, so serious that the same Obama he will define it in a speech “September 11th of the Environment”. To understand exactly what happened on that platform, however, we must first understand how a oil well.
It all starts from tower (in jargon derrick) that we see at the top of the platform that allows you to descend to the seabed inside a guide tube (said “riser”) a system of drilling composed of steel rods is one rotary cone chisel to dig the bedrock and reach the oil.
As the drilling progresses, at certain intervals, the excavated section of the well is lined with a steel column in turn cemented to the rock itself to make sure the walls hold up and don't collapse on themselves.
Deepwater Horizon, the largest oil environmental disaster in history
During all drilling phases, a so-called safety system is installed on the seabed Blow Out Preventeror BOP. The system can be activated either automatically or manually by the technicians on the platform. The BOP is essential because oil can escape ad very high pressure from the well and if this pressure is so high that it is uncontrolled it is called kick. In this case, oil could rise again drilling pipereach the platform and that would be enough minimal spark to do to blow up everything and have a so-called “blowout”.
To prevent this from happening, there are BlowOut Preventers or BOPs. They are like gods “caps” inside which there are a series of rubber discs And metal jaws which reduce and interrupt the flow of oil, preventing it from rising up to the platform.
The 5 problems that led to the disaster
As we will see shortly, the disaster on the Deepwater Horizon will not be caused by a single problem but, unfortunately, by many 5 different problems which, in a very short time, led to the explosion of the entire platform.
Problem 1 – Concrete
The Deepwater Horizon drilling platform was located approx 80km from the coast of Louisiana and his job was to finish drilling the Macondo well which would have allowed the BP company to extract oil and gas from the ocean floor of the Gulf of Mexico in the following years. April 20th at 8.45pm a test was taking place on board the Deepwater Horizon to verify the resistance of the well.
Well, do you remember that to dig the well and ensure its stability, protective steel tubes were cemented to the walls of the hole? This test demonstrated that the cement used it was absolutely not of the right quality and in fact he did not manage to resist as one would have expected. Then during the test, all of a sudden, this began to give waygiving life to a kick, that is, a sudden mix of oil, gas and drilling mud that began to rise from the well.
Problem 2 – Human error
Immediately after we have the second problem, that is, the operators they misinterpreted the test data, thus failing to identify the uncontrolled ascent. That is, they didn't realize what was happening. The result? The BOP is not operated on time. At 9.42pm then, in less than an hour, the gas and oil flowed up the drill pipe and reached the surface, gushing out of the derrick and dousing the entire platform with highly flammable fuel. At this point the workers manually activated the BOP.
Problem 3 – The BOP
The third problem is that the BOP system did not work as well as expected. In fact, first the rubber seals were activated but the kick was so violent that the drill pipe moved relative to its axis and therefore the blocking system was unable to seal it completely. In the “little space” left between the pipe and the BOP the fluids passed with such pressure that erode both the rubber seal and the tube. At 9.47pm the operators also activated the jaws to seal the tube but, as you will have understood by now, here we have the fourth problem.
Problem 4 – Batteries
In fact, it was soon realized that the systems of batteries which would have operated some of these jaws they actually were downloads and, therefore, these were not activated. Essentially, the oil continued to flow with nothing to stop it. In the meantime, the reigned on the platform chaos And the electricity went out. Suddenly a happened violent explosion And after 10 seconds another one.
Problem 5 – Gas management
We don't know for sure what he has triggered these explosions but it was probably one spark in the engine room which, in turn, would have set the gases on fire ascended from the well with the kick. In reality, there was a system on board to manage the gases which should have prevented them from reaching the engine room, but as you may have guessed, it didn't work properly. Here is also the fifth problem: the gas management system was malfunctioning.
Furthermore, the platform began to move from its correct position and therefore the drill pipe did broke a short distance from the seabed. At 9.52pm it was automatically activated jaw “of emergency”, that is, that system internal to the BOP that it would have cleanly cut the tube of drilling, sealing it. The problem is that the pipe in the BOP was in the meantime bent over due to the very strong pressure of the kick and therefore the cut it didn't come out as clear as expected. For this reason the jaw was unable to completely seal the well and the oil continued to flow.
In the meantime, the Mayday was launched on the surface and in the following hour the coast guard brought her to safety 115 people, included 17 seriously injured. 11 workersInstead, they lost their lives. As for the platform, this will continue burn for two daysafter which it will sink in the Gulf of Mexico.
The closure of the well
In all this the well, deep down, continued to flow spewing oil. Consider that the head of the well was beyond 1500 meters deep and therefore the interventions to close it were very complicated. BP engineers finally managed to place some sort of hermetic cap of approximately 40 tons and to definitively close the oil spill 15th of Julyafter well 87 days. During this time they were lost to the waters beyond half a billion liters of oil and they will be contaminated further 2000 km of coastlineespecially in Louisiana, turning the Deepwater horizon into the largest oil disaster in US history.
