Deepwater Horizon: Oil spill relief well under way

BP has started drilling a relief well to intercept and isolate the well spilling oil in the Gulf of Mexico. The operation started on Sunday.

Offshore staff

HOUSTON – BP has started drilling a relief well to intercept and isolate the well spilling oil in the Gulf of Mexico. The operation started on Sunday.

The aim of this program, in 5,000 ft (1,524 m) of water, is to intercept the existing well around 13,000 ft (3,962 ft) below the seabed and permanently seal it. The new drill site is around half a mile from the leaking well in Mississippi Canyon block 252. Drilling should take around three months to complete.

BP has also conducted a second approved trial injection of dispersants directly into the oil flow close to the main leak on the seabed. The technique is intended to mix the oil and dispersant, breaking up and dispersing accumulations of oil and allowing them to degrade naturally, thereby reducing surface impact.

The company also claims to be making rapid progress in constructing a coffer dam, or containment canopy. A 14 x 24 x 40 ft (4.2 x 7.3 x 12.2 m) steel canopy has been fabricated with other-sized canopies under construction or being contracted. Once the canopy is lowered over the leak site and connected by pipe, it is designed to channel the flow of oil subsea to the surface to allow processing and storage on board a specialist vessel.

Weather permitting, first installation of a canopy on site should start next week, allowing testing and commissioning to begin.

Close to the seabed, BP is employing up to eight ROVs to work on the blow-out preventer and subsea equipment. 

Current estimates from the US National Oceanic and Atmospheric Administration (NOAA) suggest around 5,000 b/d of oil are escaping from the well.

Weather has been hampering surface operations, but should improve over the next few days. BP currently has 230,000 gallons of dispersant available for deployment once the sea is calm enough, with a further 208,000 gallons on order. Offshore booms and specialist oil spill response vessels, skimmers and barges will return to operation in calmer seas, treating and collecting as much oil as possible before it reaches the coast.

Onshore activity is focused on six locations: Venice and Port Sulphur, Louisiana; Pascagoula and Biloxi, Mississippi; Mobile, Alabama; and Pensacola, Florida. Staging posts are being stocked with people and material to help protect the shoreline in each area. Work is continuing to install marine protection booms along the coast. Hundreds of thousands of feet of boom have been deployed, with 2,000 volunteers so far trained to assist in the response effort.

BP estimates the present cost to the MC252 owners of containing the spill and securing the well at over $6 million per day, adding that it is too early to quantify other potential costs and associated liabilities.


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