The Deepwater Horizon oil rig exploded on April 20, 2010, killing eleven men. The oil rig then sank on April 22, 2010. Since then, oil has been spilling into the Gulf of Mexico. Attempts to stop the oil spill have been met with only limited success.
Currently, BP is trying what is called a “top kill” method to plug the leak. The top kill method involves pumping a heavy mud into the broken well. The idea is that this heavy mud will stop the oil and gas that is rising to the surface. If that is successful, the well can then be capped with concrete.
However, the question remains: What caused the well to fail in the first place? Halliburton’s representative at the congressional hearings, Tim Probert, may have just given everyone the answer. Probert presented a schematic of BP’s cementing plan to Congress. The drawing shows a key design flaw that may be the cause of, or a contributor to, the catastrophe. The graphic shows that a liner hanger was not inserted between casings 8 and 9. That missing liner hanger could have allowed gas into the well, which led to the catastrophe.
Click on the image to the right to see it in full-resolution.
The graphic shows the wellhead 5,067 feet below the water’s surface and the bottom of the well more than 13,000 feet below that. It diagrams how the drill pipes telescoped down in sections — some about 2,000 feet long, some shorter and others longer.
With each section, one metal tube fits inside another, leaving a space called an “annulus” where heavy drilling mud can circulate and carry the drilled-out material back up to the surface. According to the diagram, one of the spaces between different-sized pipes was not closed off — a no-no, according to some experts.
A little echo in that well? “The top kill method involves pumping a heavy mud into the into the broken well.” 🙂
Doh! Thanks for pointing that out. Fixed.