BP has released this infographic, Relief Wells & Subsea Containment, showing how they plan to seal the oil well leak in the Gulf of Mexico, and the current progress at 8,788ft.
British Petroleum intends to drill two wells designed to intersect the original wellbore above the oil reservoir. This will allow heavy fluid to be pumped into the well which will stop the flow of oil from the reservoir. Cement will then be pumped down to permanently seal the well.
BP needs to cement 7 casings into place before the relief well can intersect with the main drill pipe which is pouring approximately 5,000 barrels of oil per day into the ocean. They have completed 3 casings, with 4 remaining. They have reached a drill depth of just below 10,000 feet, with another 8,000 feet remaining. At about 12,000 feet they will begin angling toward the center of the damaged oil pipe.
BP has estimated that the project will require 90 days to complete the first relief well.