Despite all the doom and gloom scenarios being played out in the news and on the internet, BP does have a way to plug the Deepwater Horizon gusher that makes sense and can realistically work. The fix is not immediate nor is it the absolute easiest maneuver to pull off, but it is reasonable and underway at this very moment. It also demonstrates by the manner of their approach that they are taking every precaution with this plan which is something they should actually be credited for as there is little use faulting them when they do implement something correctly.
Relief wells are the simple answer, but not the full answer. BP has not denied that there is likely damage to the pipe that lines the Deepwater Horizon well around 1,000 down. Because of that possibility combined with the extremely high pressure that is being dealt with, capping the well by traditional means is not only unsafe but almost sure to fail. Under normal circumstances, a well is capped from the top and that is the end of the problem, but this is far from being normal circumstances.
Relief wells are used to contain oil well blowouts. Normally this is something done on land, so working underwater does pose some extra challenges, but it is not something that has never been done before so it is within the realm of reasonable. A relief well is designed to relive pressure as its name suggests which lessens the output escaping the main well. In the case of this particular BP well, relief wells are going to need to be drilled in at an angle that intersects the main well around 18,000 or so feet below sea level.
One relief well is all that is required really, but BP is drilling two just in case something goes wrong so that they do not wind up paying a hefty price for unforeseen delays or in the event of a drilling collapse. While this is being done, top spill containment remains the mission so as to try to minimize the damage until one of the relief is completed. It may sound very simple, but when you consider that you need to find a 7 inch pipe at 18,000 feet, easy is not a part of the equation.
Once the relief does find that original well pipe, the next step is to pump in heavy drilling mud. The purpose of this is causing downward pressure with the mud which is hopefully sufficient to counteract the upward pressure of the escaping gas and oil. Eventually, it will produce that effect, the only question is how long it will take. Once the upward pressure has been sufficiently counteracted, the escaping oil and gas will cease. At that time cement is pumped in via the relief wells, and the offending damaged well is capped at the bottom.
The process of capping from the bottom is more difficult and will take longer. It is likely not going to succeed on the first try as properly intersecting the damaged is not going to be easy. BP has made this very clear and it is a part of the reason two relief wells are being worked on simultaneously. Once the well is successfully capped, real progress will be seen regarding the efforts to clean up top spill. The main concern right now is the weather as any serious weather conditions can mean shutting down operations and having to move ships out of the area which can cost anywhere from a few days to a week or more of delays.
There is no hard and fast timetable for how soon the relief wells will be completed, but the most conservative estimates factoring in all the worst case scenarios possible, ie; technology and equipment problems, bad weather, and missing the mark with the first relief well, all still indicate that it should be successfully capped before the summer ends. More optimistic estimates say it is possible the effort could be completed mid August.