The ‘‘nightmare well’’ is dead. But the Gulf coast’s bad dream is far from over.

Federal officials declared Sunday that the well where the Deepwater Horizon rig exploded had finally been killed. Workers drilled a relief well into the damaged one and drove a cement stake deep into its oily, black heart.

Its official end came 11 years after Texaco first sank an exploratory well near that same spot 50 miles out in the Gulf of Mexico, then moved on after finding it unprofitable. When BP PLC purchased the rights to explore for oil there in 2008, it held an in-house well-naming contest. The winning team chose the name Macondo, after the mythical town from Gabriel Garcia Marquez’s novel ‘‘One Hundred Years of Solitude.’’

Carved out of a ‘‘paradise of dampness and silence,’’ the Macondo of the story is a cursed place, a metaphor for the fate awaiting those too arrogant to heed warning signs.

BP’s name choice came to seem prescient last April 20.

That day, an explosion on the rig — which had drilled the well and was in the process of capping it — killed 11 men instantly and started a slow-motion disaster that has jeopardized the livelihoods of legions of fishermen, hotel and restaurant workers, drilling employees and others.

In the three months before a temporary cap stemmed the flow from the blown-out well, as much as 172 million gallons of oil and millions of cubic feet of natural gas spewed into Gulf waters.

For those most directly affected by the spill — the ones who still await BP checks for lost wages and revenues, who live on beaches where oil mats are just now coming ashore — the feeling of helplessness remains raw, like a freshly stitched wound.

‘‘If you had to live with all the uncertainty, for all those months,’’ says Mike Helmer, a fishing guide out of Lafitte, La. ‘‘I can promise you it’s not easy. And it’s not over.’’

At the well’s death, Associated Press reporters who covered the disaster checked in with scientists awaiting test results, with business and legal analysts seeking answers and resolutions, and with Gulf residents looking to an uncertain future and struggling against the ‘‘quicksand of forgetfulness’’ that consumed the fictional Macondo. Here are their reports.

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DRILLING FOR ANSWERS

Before the smoke even cleared, fingers of blame were pointing in many directions.

BP’s internal investigation, released earlier this month, accused subcontractor Halliburton of improperly cementing the well. It blamed rig owner Transocean Ltd. for problems with the blowout preventer on the seafloor a mile down. It even pointed at itself, acknowledging that if the results of a critical pressure test had been correctly interpreted, workers would have known something was horribly wrong in time to do something about it. (It was a BP engineer who once described Macondo as a ‘‘nightmare well.’’)

While the company’s report went a long way toward previewing its legal strategy and explaining how a bubble of explosive gas made a 3-mile-plus journey from the bottom of the well to the drilling rig, it left many questions unanswered.

Those questions will be addressed by government investigators, other companies’ investigations, congressional committees and by examinations of key pieces of evidence plucked from the seafloor.

Some of those probes are looking specifically at factors BP downplayed — including the company’s well design.

The conclusions will help determine who is liable for the worst offshore oil spill in U.S. history, and what share of the blame — and of the bill — the various companies with ties to the rig and its equipment will be responsible for. Based on an upper estimate of the oil spilled, BP and others could be fined up to $5.4 billion for violating water pollution laws, or up to $21 billion if gross negligence is found.

The blowout preventer, perhaps the most critical piece of evidence, now sits under guard at a NASA facility in New Orleans, awaiting forensic analysis.

‘‘The whole matter of the BOP, whether it worked or didn’t work … could change the whole outcome of the whole investigation,’’ says Daniel Becnel, an attorney representing a host of plaintiffs in the consolidated federal court case.

The examination, however, is not set to begin until at least Oct. 1, according to internal e-mails and court documents obtained by AP. Meanwhile, scientists with the U.S. Geological Survey are analyzing pieces of debris that rained down on an adjacent cargo ship, the Damon Bankston, during the blast.

This rocklike debris, which could be cement or chunks from the sea floor, will also help piece together what went wrong inside the well.

— By DINA CAPPIELLO, Washington, D.C.

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TO DRILL, OR NOT TO DRILL?

One of the supreme ironies of this disaster is that many of those hurt most by the spill find themselves having to defend the industry that caused it.

While acknowledging that we are only slightly better prepared to handle a big spill now than we were five months ago, Gulf state officials have joined oil interests in fighting a federal moratorium on deepwater drilling. A government report released Thursday says the ban may have temporarily cost 8,000 to 12,000 jobs on oil rigs and elsewhere.

The current ban on new deep-sea drilling is set to expire on Nov. 30. But there is little doubt the oil and gas industry will face even tougher regulations afterward.

Immediately after the explosion, it became apparent that BP, the industry and the government were woefully unprepared. There was no ready plan for capping a leak so deep underwater, and the cleanup and containment equipment had to be cobbled together on the fly.

The situation was unprecedented, industry and government officials told the public.

Gary Rook, technical director of Edison Chouest Offshore, whose vessels played a key role in the containment effort, says the industry needs to develop higher storage capacity for recovered oil, design and deploy more effective skimming boats and create a game plan that allows critical response assets to be deployed immediately after a disaster.

But Rook said some federal regulations — such as the ones that limit the size of offshore response vessels — also need to be revised.

‘‘We need to get equal to the rest of the world,’’ he says.

Retired Coast Guard Adm. Thad Allen, the government’s point man on the BP spill response, says there also needs to be a reevaluation of existing contingency plans. That should include a look at what people think about the role that responsible parties should have in the cleanup effort, and how much autonomy and flexibility state and local governments should have to act outside the national command structure. For instance, federal officials clashed with their counterparts in Louisiana over plans to build artificial barrier islands off the coast to block incoming oil.

Four oil industry giants have pledged to spend $1 billion developing equipment and procedures to better address spills in the future. But that effort is not expected to bear fruit anytime soon.

‘‘I think we’re getting there,’’ says Michael Bromwich, director of the newly formed Bureau of Ocean Energy Management, Regulation and Enforcement, successor to the disgraced regulatory agency, the Minerals Management Service. ‘‘The progress is visible, but we need to make sure and ensure the public that the bar has in fact been raised.’’

Meanwhile, BP executives and owners of independent U.S. gas stations that carry its name plan to gather next month to craft a new marketing strategy and try to revive the BP brand.

— By HARRY R. WEBER, New Orleans.

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ASSESSING THE DAMAGE

There’s an old saying among fishermen: It’s better to be lucky than smart. Bad as things are in the Gulf, Steve Murawski, a pretty smart guy, says we got damned lucky.

On April 29, a mere nine days after the rig explosion, the Gulf’s so-called Loop Current was at full strength, says Murawski, chief fisheries scientist for the National Oceanic and Atmospheric Administration. Under those conditions, it had the potential to take any oil that got into its pinwheel-like effect and spin it into the Florida Keys and up the U.S. East Coast.

Then, just days later, a large eddy blocked the current and broke the Loop’s back. The threat disappeared.

‘‘This is the closest thing to an act of God that we’ve seen,’’ says Murawski.

As the oil continued to gush, scientists and others feared a near-knockout blow to the Gulf’s already stressed ecosystem. Early signs suggest that didn’t happen.

In parts of Louisiana, some marshlands seem already to be recovering. The oil-munching microbes that scientists feared would create dead zones ultimately failed to reduce oxygen levels as severely as predicted.

Yes, oil continues to wash up in places, but the streaky surface sheens have all but vanished. And while nearly 6,600 dead birds, sea turtles and other animals were recovered, new victims are rarely found.

‘‘I think the resiliency of the Gulf has been endorsed and exceeded even optimistic estimates,’’ says George Crozier, director of the Dauphin Island Sea Lab in Alabama.

But underwater, things get a bit murkier.

Scientists have found plumes of oil — microscopic and unseen — below the surface. A University of Georgia expedition this month found patches of oil, some up to 2 inches thick, on the Gulf floor.

That’s oil that can be brought back to the surface and onshore with a storm, says University of South Florida chemical oceanographer David Hollander.

Hollander has found plankton, the base of the marine food web, that bear the hallmarks of having been poisoned. He worries about what that means for fish larvae and eggs — future generations of sea life.

An August federal report declared that all but about 52.7 million gallons of BP’s oil had been burned, skimmed, chemically dispersed, naturally dispersed, evaporated or dissolved. Scientists roundly criticized that report as too rosy.

Things are as positive as they are, Hollander and others say, because we were lucky AND smart.

In addition to the fortunate change in the Loop Current, wind patterns kept the oil from spreading and staying close to the shore in Mississippi, Alabama and Florida, says Murawski. Of course, those states’ fortune was Louisiana’s misfortune.

Credit also goes to those who decided to use massive amounts of chemical dispersants deep underwater to break up the oil. Some say we traded certain slicks for unknown problems below the surface, but Crozier and other initial opponents now concede that it seems to have been the right move.

But the effects of the 1989 Exxon Valdez oil spill in Alaska and the 1979 Ixtoc disaster off Mexico’s Yucatan Peninsula are still unfolding, so only time will tell.

— By SETH BORENSTEIN, Washington, D.C.

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PAYING UP

Three weeks into the $20 billion oil spill claims process set up by BP and the Obama administration, tens of thousands of people are waiting much longer than promised for their money. And many are getting only a fraction of what they requested.

Claims administrator Ken Feinberg acknowledged in recent public appearances that there are ‘‘serious problems’’ with the payment of claims, which he initially said would take just 48 hours for individuals and seven days for businesses. Much of the delay involves lack of documentation and the unexpected complexity of many claims.

‘‘We do not have the kind of results that we all want,’’ Florida Attorney General Bill McCollum said after meeting with Feinberg. ‘‘People simply aren’t getting their claims paid and they have urgent need for them.’’

As of Friday, about 26 percent of more than 68,000 claims had been paid for a total of $193.3 million. Loss of earnings or profits makes up the majority of claims, yet most of those paid so far involve $25,000 or less. Only one claim had been denied.

‘‘Most of my clients who are getting paid are not getting the amount they requested,’’ says attorney Rhon Jones, whose Montgomery, Ala., firm represents more than 1,000 people and businesses with oil-related claims, lawsuits, or both. ‘‘There is just lots and lots of frustration.’’

Florida and Louisiana account for nearly 60 percent of the claims submitted, followed by Alabama, Mississippi and Texas.

The claims being processed right now are interim, emergency payments. On Nov. 23, the Gulf Coast Claims Facility will begin working out larger, final settlements, the rules for which are expected to be released in about a month.

Feinberg has said those rules will include a requirement that claimants give up their right to sue BP — and possibly the other companies involved in the oil spill — in exchange for the final settlement. People and businesses will have three years to submit that final claim.

Meanwhile, in New Orleans, more than 300 spill-related lawsuits are being consolidated for pretrial rulings before U.S. District Judge Carl Barbier. BP is skirmishing with plaintiffs’ lawyers over the timing of the release of evidence, preferring a slower pace that could force more people to make the tough decision about whether to accept a claim payment or pursue a lawsuit.

‘‘The longer they string this out,’’ says Jones, ‘‘the more people will be under financial duress and the more likely they will take a smaller number.’’

— By CURT ANDERSON, Miami.

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SCANNING THE HORIZON

Ousted BP CEO’s Tony Hayward predicted a ‘‘very modest’’ environmental impact from the spill, and some observers say the relatively few dead sea animals found show he was right.

Critics counter with questions: How many of the dead sank to the bottom and were not counted? How many of the sick and weakened will die prematurely?

Third-generation fisherman Byron Encalade is sick of body and of heart.

For the first season in as long as he can remember, the 56-year-old from Pointe A’La Hache, La., is not out shrimping. He’s not out gathering oysters — they’re all dead. All of the drivers for the Delta family’s Encalade Trucking and Fisheries have moved on to new jobs elsewhere.

‘‘Emotionally, I have family that depends on me,’’ says Encalade, a proud member of this primarily African-American community. ‘‘I’ve got one boat working for BP, and I’ve got about six families we’re trying to take care of off that one boat. I got my share of responsibilities.’’

While large areas of commercial fishing grounds have been reopened, demand for Gulf seafood has tanked, and prices have plummeted. Tourists have slowly begun returning to the Gulf’s white-sand beaches, but a summer’s revenues have been lost.

‘‘You got to respect the resiliency of these people, but you have to feel for them…,’’ says Adm. Allen, the government’s point man. ‘‘This oil spill went beyond physical damage. We were threatening ways of life, how people had grown up, how they were raised, the watermen who operate down here. This is very traumatic to this area.’’

While many have stayed afloat with claims checks and spill-related work from BP, some have lost their homes or laid off workers in a bid to make it through the winter. Helmer, the fishing guide, refused to work for the company he blames for his predicament.

After years of working for others, Helmer picked this year to go into business for himself. Even with most of his competitors contracting with BP, paying charter bookings have been hard to come by.

‘‘It’ll be several years before I feel better,’’ he says.

Like so many Gulf residents, Encalade spent some time in the oil industry. But he knew where he truly belonged.

‘‘I always came back to fishing,’’ he says. ‘‘That is the one thing we have lived our lives knowing: Well, I always got my bayous and my swamps and my bays, and I can go make a living.’’

The water, he says, was his ‘‘main source of independence.’’ No longer.

‘‘I can’t even go catch myself a plate of food anymore.’’

— By BRIAN SKOLOFF, Ocean Springs, Miss.

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As humans, particularly as Americans, we have a tendency to want quick answers and quicker fixes. But nature doesn’t work that way.

After all, says Columbia University marine geologist Roger Anderson, this disaster was several ages in the making.

Many eons past, perhaps 40 million years ago, tiny plants and microorganisms died and were washed into the area that would one day be the Gulf of Mexico, says Anderson. Maybe 3 million years ago, a landslide occurred, covering the area with sand. Under the immense pressures of water and sediment, the dead plants and protozoans decayed and cooked.

As the continents shifted and the Gulf widened, fractures allowed the buoyant materials to migrate upward toward the bottom of what had become a great salt-water sea. Then, a few years ago, a blink in geologic time, humans first went after that brew.

And now, some of the marine life killed by the Macondo spill has already begun the process of becoming a future oil deposit, Anderson notes with a hint of irony in his voice.

‘‘We’re always burying new organisms to start the clock again,’’ he says.

This particular well may have been declared dead, but the reservoir is still there. Anderson has no doubt that somebody will tap it someday.

‘‘A little more carefully, we hope.’’

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Associated Press video journalist Rich Matthews also contributed to this report.