New York (Platts)--5May2010/604 pm EDT/2204 GMT

BP hopes to begin use of a subsea containment system at the leaking Macondo well in the US Gulf of Mexico on Monday, a company official said Wednesday. The container left port on Wednesday en route to the well site, some 40 miles offshore Venice, Louisiana.

By using the container, BP hopes to corral the leaking oil at the wellhead and funnel it up to a waiting vessel at the surface. The process has been used in shallow waters before, but never at the nearly 1-mile depth of the Macondo well.

BP executive Doug Suttles, during the daily press briefing on the spill response, also said the company has temporarily halted the use of underwater dispersants to assess their effectiveness and impact on the environment.

After the 100-ton chamber is fitted on the seafloor, it is possible hydrates, or ice plugs, could form, due to the pressure and low temperature, BP officials said during a separate press briefing on the technology employed by the containment system.

The company will run a riser outside the drill pipe to pump warmer surface water down to where the containment chamber is, they said. In addition, methanol will be injected, since it can melt hydrates.

"This has never been done before," said one official during the call. It will "take a few days just to stabilize this system."

After moving to the surface for processing in a drillship, the crude will be sent to BP's Texas City, Texas, refinery and some other Gulf Coast locations for further processing, said the officials. It will be off-spec crude, with extra water in it, they said.

A second containment dome is now being fabricated; however, BP would rather not put one over the blowout preventer (BOP), where more oil is leaking, since that blocks their ability to fix the BOP, they said.

--Gary Taylor, gary_taylor@platts.com

--Beth Evans, beth_evans@platts.com