BP's latest bid to contain spill is to cut and cap leaking pipe
BP's latest bid to contain the disastrous Gulf of Mexico oil spill involves cutting and capping a ruptured well pipe about a mile beneath the ocean's surface and then siphoning the crude spilling into the sea up to a waiting ship. The White House said...
BP's latest bid to contain the disastrous Gulf of Mexico oil spill involves cutting and capping a ruptured well pipe about a mile beneath the ocean's surface and then siphoning the crude spilling into the sea up to a waiting ship.
The White House said the process of placing the unit BP hopes will stem the flow of oil - the lower riser marine package - on top of the damaged blow-out preventer on the undersea well got under way yesterday.
BP officials told AFP that installing the unit, which is in fact a replacement unit for the top half of a large valve, known as the blow-out preventer (BOP) stack, involves a couple of difficult operations using robots.
First, the damaged riser that is spewing oil into the sea will be cut at the level of the sea bed using shears. Then a second cut will be made at the point where the riser inserts into the blow-out preventer stack.
The second cut will be made with a high-precision diamond saw because it has to be flush with the BOP stack to allow the cap of the riser package to be placed and sealed on top of the damaged unit.
After it has been cut, the damaged riser will be removed by crane and the new cap will be lowered into place and sealed onto the unit.
When the damaged riser is removed, the flow of oil into the Gulf of Mexico will temporarily increase.
The new unit is connected to a riser extending from a drillship on the surface, which will collect the oil.
The seal on the new cap is designed to decrease the potential for seawater to leak in and improve the efficiency of oil recovery.
Lines carrying methanol are connected to the device to help stop ice-like hydrates from forming when cold sea water mixes with natural gas.
Hydrate formation thwarted the first attempt to stem the flow of oil by lowering a "top hat" onto the spewing well.
BP has stressed this latest attempt will not stop the flow of oil but only stem it until two relief wells have been drilled. The drill wells are expected to be finished in August.