President Trump on Wednesday was poised to sign the new tax bill, passed by Congress, which lifts a decades-old ban on oil and gas drilling in the Arctic National Wildlife Refuge in northeastern Alaska. Here’s a look at what might happen now.

Will exploration begin immediately?

No. Both supporters and opponents say it could be years before the first lease sale, a precursor to any drilling. The new legislation requires that the Department of Interior conduct one sale within four years and a second within seven. But there are many steps that must be taken before those sales can be held, and the process is not completely clear. Lawsuits and other actions by opponents of drilling could slow things, both before and after any lease sales.

The Interior Department will have to identify lands in the 1.5 million acres of the refuge along the coastal plain, known as the 1002 area, for leases. Once the department comes up with a list of options, there will be at least one comment period in which the public will have a chance to be heard.

One question mark is whether new seismic studies will be undertaken. Such studies can reveal underground formations that have high oil development potential, and the only ones that were done in the refuge are more than three decades old.

Based on the old studies, the United States Geological Survey has estimated that the 1002 area contains from 5 to 16 billion barrels of oil. David W. Houseknecht, a senior research geologist with the survey, said the agency was about to re-analyze the data using improved software in hopes of reducing the uncertainty of that estimate. But new studies using modern three-dimensional technology could produce even better estimates.

The Interior Department in September proposed allowing new studies, but it is unclear whether oil companies, if allowed, would undertake them, or whether the Interior Department would wait for them to be done before conducting a sale. Oil companies have bid on drilling leases in other areas with less-than-ideal information.

What can Democrats do?

For now, not much. The Democrats’ ability to halt progress toward drilling in the refuge hinges on the party’s ability to recapture the majority in one or both houses of Congress in the 2018 midterm elections.

“We’re going to take our case to the American public now,” Senator Maria Cantwell, a Washington Democrat who has led the fight against drilling in the refuge, said Thursday.

Senator Edward J. Markey, Democrat of Massachusetts, said he believed voter outrage was coalescing around a number of Trump administration actions, including rolling back environmental regulations and moving to withdraw from the Paris agreement on climate change. Opening the Arctic refuge to drilling will be a “tipping point” with voters, he predicted.

“When we win in 2018, we will then ensure accountability on this and begin the process of reversing legislatively what has happened,” Senator Markey said. Democrats’ ultimate aim, he said, would be to give the Arctic refuge permanent legal protection.

What about environmentalists?

Potentially more than Democratic politicians, at least in the nearer term.

Environmental activists have said they would work with Democrats in Congress, but would also seek to block drilling through legal or procedural means and by mobilizing public opinion against it.

Adam Kolton, director of the Alaska Wilderness League, alluded to a new media campaign but did not provide details.

Suzanne Bostrom, an attorney for Trustees for Alaska, an environmental law firm, vowed that opponents of drilling would fight the Department of Interior “every step of the way.” She did not detail activities that might prompt lawsuits or other legal actions.

“This is certainly not a short process or something that’s going to play out immediately,” Ms. Bostrom said.

What will the oil industry do?

Kara Moriarty, president and chief executive of the Alaska Oil and Gas Association, an industry group, said that recent speculation that oil companies were not interested in drilling in the refuge was inaccurate. “Industry support for having access to the coastal plain has never wavered,” she said.

Helping to fuel that speculation was a disappointing federal oil lease sale in another part of Alaska several weeks ago. But Ms. Moriarty said that a sale of leases on nearby state-owned land at the same time had been successful. And the state’s varying geology makes it difficult to compare the prospects for different regions, she said.

Dr. Houseknecht said that the geological survey had received calls from companies as far away as Australia wanting to know how they could get access to the existing seismic data. (The answer: Only by forming a partnership with one of the 11 current companies that paid for the work.)

Ms. Moriarty said that although there was industry interest in drilling in the refuge, the threat of lawsuits by environmental groups meant that it was crucial for government and industry to take time and do everything correctly.

Robert Dillon, a consultant and former aide to Senator Lisa Murkowski, the Alaska Republican who championed the drilling provision, said that those who supported opening the refuge were not bothered by the prospect that oil might not actually flow for many years.

“We’re not planning for tomorrow,” Mr. Dillon said. “We’re planning for 10, 20 years from now. We’re talking about the next generation of Alaskans.”