Five months after an explosion sank a BP PLC-hired drilling rig and sparked the worst offshore oil spill in U.S. history, drilling crews have intercepted the blown-out well and are preparing to deliver a death blow by tomorrow -- action that many say will also kill any chance of a Senate spill-response bill this year.

A relief well burrowed nearly 2.5 miles beneath the Gulf of Mexico sea floor yesterday intercepted the British oil giant's ruptured well, retired Coast Guard Adm. Thad Allen, the federal official overseeing the response effort, said yesterday.

And BP today said tests showed no oil or cement present at the intersection point, an indication that the ruptured well is stabilized and only requires a sealing procedure to kill it for good. The final step in the well-killing procedure involves pumping cement into the cavity around the failed wellbore's pipe-like casing and the rocky walls of the wellbore.

"It is expected that the ... well will be completely sealed on Saturday," BP said in a statement.

The anticlimactic final shutdown of the well comes two months after crews successfully stemmed the flow of oil and gas into Gulf waters with a top kill procedure that pumped mud and cement down the wellbore from the top. Crews continued drilling the relief well after that success as a backup to ensure conditions were stabilized at the bottom of the well.

The mid-July top kill success may have led to a collective sigh of relief among BP workers and federal responders, but it all but killed any chances of a congressional spill response this year.

Observers say the shutdown of the well and the White House's claims of limited lasting environmental damages have diminished the push to pass spill-response legislation this fall.

The House passed a sweeping oil spill-response bill in late July. The Senate, meanwhile, made plans to consider dueling energy and oil spill-response bills in early August, but Majority Leader Harry Reid (D-Nev.) pulled them from floor consideration at the last minute when it was clear neither bill had enough support for passage.

Reid has promised to resurrect the oil spill-response legislation this fall, and an aide last week said he would likely do so after the November election. But observers are not so sure.

"It is not at all clear there is a -- no pun intended -- reservoir of political capital left on oil spill legislation," said Scott Segal, an industry attorney at Bracewell & Giuliani, this week when discussing chances of Senate passage of energy legislation this fall. "There doesn't seem to be a need to pass it so quickly, particularly after the midterms."

If Senate leaders do make good on their promise to bring spill-response legislation back to the floor, a likely sticking point will revolve around language dealing with oil companies' oil spill liability.

Reid's bill this summer included a clause that would have eliminated the current $75 million liability cap for companies involved in a spill. But Republicans and some moderate oil-state Democrats were loathe to support such a measure, saying it would exclude all but the largest energy companies from operating offshore.

Sen. Mary Landrieu (D-La.) and Mark Begich (D-Alaska) were two of the most vocal opponents of the language, refusing to vote for Reid's package because of it. They have proffered their own proposals to address the liability issue. The current $75 million cap is too low, they say, but a compromise could be reached that holds companies accountable without placing a burden on taxpayers and without shutting out smaller companies from operating offshore.

The senators offered up similar proposals addressing liability just before the Senate left for the August recess, and they say they are working to iron out the differences.

The senators yesterday told reporters those plans had been waylaid by the Senate's work this week on the small business-lending bill that passed yesterday. But Begich said they plan to dive back into talks next week on setting a deal. Both have said chances of considering a bill are slim until after the November midterm election.

Reid and Sen. Robert Menendez (D-N.J.), the author of the unlimited liability language in Reid's bill, have said they are willing to consider compromise liability language.