WASHINGTON - The federal government's oil-spill chief said Tuesday that seepage two miles from BP's oil cap was coming from another well, tamping down fears that leaks mean the ruptured well is unstable.

Retired Coast Guard Adm. Thad Allen also said five leaks in and around BP's well were more like "drips" and were not yet reason to worry.

The leaks and seepage had raised concerns that the mechanical cap choking off the flow of oil was displacing pressure and forcing oil out deep underground. That could make the seafloor unstable and make the three-month-old environmental disaster even worse and harder to fix.

Allen said the well appeared to be stable, and he extended testing of the experimental cap by another day, which means the oil will remain shut in.

The cap is buying time until a permanent plug is in place. Crews are drilling into the side of the ruptured well from deep underground, and by next week, they could start blasting in mud and cement to block off the well for good. Killing the well deep underground works more reliably than bottling it up with a cap.

Allen also said he was considering whether to pump mud and cement through the well cap, smashing the oil in from two directions. The idea is similar to the failed top-kill plan that could not overcome the pressure of the geyser pushing up.

BP and Allen said it could work now because there's less oil to fight against.

The seepage was detected over the weekend, and was the first sign of trouble after the cap was closed Thursday.

But Allen said Tuesday that another well was to blame.

"In fact, it's closer to that facility than" the one that blew out, Allen said. "The combination of those factors and the fact that it's not unusual to have seepage around the old wells led us to believe that we could exclude that as a potential source of leakage from the particular wellbore."

Biden visit

There are two wells within two miles of BP's blowout, one that has been abandoned and another that is not in production. About 27,000 abandoned wells in the gulf are not checked for leaks, an Associated Press investigation showed this month.

Allen said he would accompany Vice President Biden on a trip to the gulf Thursday. The White House said that Biden would visit Theodore, Ala., to assess the government's and BP's efforts to respond to the disaster and to meet with affected residents.

Biden made his first trip to the region in late June.

From 94 million to 184 million gallons have gushed into the gulf since the Deepwater Horizon rig exploded April 20, killing 11 workers.

A BP employee told government investigators Tuesday that weeks before the explosion, he reported a leak of hydraulic fluid in a critical safety device that could have prevented the disaster.

Ronald Sepulvado, a BP well site leader, told a panel of government investigators in suburban New Orleans that he did not know if federal regulators were notified of the leak, as required.

Hill hearings

A federal regulation requires drilling operations to be suspended if a blowout preventer pod is not fully functional, but BP did not stop drilling. Sepulvado said the safety device passed the last pressure test performed 11 days before the explosion.

In Washington, two former Interior secretaries told Congress on Tuesday that they had not anticipated an accident as large as the BP spill.

But Gale Norton and Dirk Kempthorne said no one else did either, including members of Congress who are now blaming the Bush administration for failing to prevent the tragedy.

Kempthorne, who served as secretary from 2006 to January 2009, while George W. Bush was president, said he did not recall being asked at his confirmation hearing or in later congressional testimony about major oil spills.

In fact, Kempthorne said, the opposite occurred. In testimony before the House Energy and Commerce Committee, he recalled being pointedly asked why Interior wasn't doing more to expand offshore energy development, not less. Those concerns were driven by $4-per-gallon gas prices, Kempthorne said.

Norton, who served from 2001 to 2006, also under Bush, said the industry had a remarkable safety record, including during Hurricanes Katrina and Rita in 2005.

Rep. Henry A. Waxman (D., Calif.), chairman of the Energy and Commerce panel, said the Interior Department made serious mistakes under both Presidents Bush and Obama.

"The cop on the beat was off-duty for nearly a decade," he said. "And this gave rise to a culture of permissiveness."

Also Tuesday, BP said that it was selling assets in the United States, Canada, and Egypt to Apache Corp. for $7 billion to help pay the costs from the spill.

Some or all proceeds would go toward a $20 billion fund that BP agreed to last month under pressure from the Obama administration. The fund will help pay cleanup costs and damages from the spill.

BP has spent about $4 billion so far on containing and cleaning up the oil, as well as on damage claims from gulf businesses.