BP has successfully installed a new sealing cap on the leaking Gulf¹ of Mexico oil well, company officials say.

英国石油公司官员称，公司已成功在墨西哥湾油井渗漏处安装一个新的密封帽。

BP's undersea robots have fitted the sealing cap on top of the well

It is hoped the new cap will stop the leak and capture all the oil before it can pour into the sea.

But BP warned the cap system had never been deployed²（部署，配置） at such depths and said "its efficiency and ability to contain the oil and gas cannot be assured".

It also said that the two relief wells（减压井） being drilled remain the only way permanently³ to seal the leak.

That process is due to be completed by mid-August.

Meanwhile, the US government issued a new deep-water drilling moratorium⁴（暂停，中止） to replace one struck down in court.

The moratorium was reworked by the US interior department in the hope of gaining the approval of a federal court that rejected the Obama administration's earlier ban, saying it was too broad.

The new moratorium applies to any deep-water floating drilling facility but is not based on the water depth where drilling occurs. It will end by 30 November or sooner.

It is unclear whether a federal court in Louisiana will look at the new moratorium more favourably⁵.

Pressure tests

On Monday evening, Adm Allen hailed "significant progress" on the new well cap and live underwater footage showed the device being placed on top of the well.

The old cap, which it replaces, managed to contain only about half the oil escaping from the wellhead.

Adm Allen said BP would carry out tests to determine the integrity（完整，正直） of the leaking well on Tuesday morning.

"The measurements that will be taken during this test will provide valuable information about the condition of the well below the sea level and help determine whether or not it is possible to shut the well for a period of time," Adm Allen said in a statement.

During testing, engineers will close one or more valves（阀门，瓣膜） on the cap mechanism⁶, shutting down the collection of leaking oil for six to 48 hours.

Meanwhile, pressure readings will be taken to make sure there are no other leaks from the well.

The news of progress on the cap came after a visit to Florida by First Lady Michelle Obama, who urged tourists not to abandon the Gulf Coast.

"It's important for the rest of the country to know that these places are just as vibrant⁷（充满生气的，振动的） and just as beautiful as they've always been," she said in Panama City, Florida.

"And folks here in Florida and across the Gulf Coast are still depending on visitors and tourist dollars to put food on their tables and to pay their mortgages（抵押贷款） and to send their kids to college."