The runaway well spewing 4,000 tons of oil and gas into the North Sea daily can now be shut off in a day, an oil company official said today.

"One good day's work could do it," said a key official from Phillips Petroleum, which operates the well. Then he held up a pair of crossed fingers, a sign that things could still go wrong.

Weather conditions forced a halt to work today and it will not be know until Wednesday morning if conditions will improve to allow a resumption.

The Phillips official's optimistic reading was based on considerable progress made today aboard the Bravo fig where a team of seven, led by a pair of disaster specialists toiled for six hours in oxygen masks and rubber coats. The Phillips official said they finished about half their delicate and dangerous task.

Laboring under a towering 200-foot spray of oil and gas, they put in 16 bolts to fix the bottom part of a blowout protector to the well. Then they installed two "blind rams," a pair of pistons, the official, who asked not to be identified said.

Two more pieces of equipment and a valve must still be placed above this structure to complete the seal. Then, if all goes well, the valve, capable of withstanding a pressure of 5,000 pounds per square inch, will lower the pressure in the well. The two pistons of "rams" will be driven home was too good.

This, at least, is the ideal scenario, but much can happen in the unrelenting North Sea. Today, for example, the seven were driven off the rig around 1 p.m. because the weather [TEXT OMITTED FROM SOURCE]

The wind died down and a heavy gas pall hung over the Bravo - conditions under which a small park could set off an explosion. The disaster squad beat a hurried retreat to the barge serving them.

[TEXT OMITTED FROM SOURCE] and a heavy gas pall hung over the Bravo - conditions under which a small spark could set off an explosion. The disaster squad beat a hurried retreat to the barge serving them.

Tonight the wind was freshening. If this holds - and does not become too strong - the work will resume Wednesday.

At the same time, the massive task of cleaning up the oil slick began but was evidently running into trouble. The slick now covers an area of about 200 square miles, most of it a thin blue firm. In its southwest corner is a slick brown oil scum, a blob of about six square miles.

This mass was attacked with two teams of three or four ships each operating "booms" and "skimmers." The boom is an inflatable plastic belt, from 200 to 450 yards long, stretched between two ships. The boom or belt ropes in the oil, gathering it for the skimming ship.

This vessel is equipped either to sweep or suck the goo up, but the entire process is still in a stage of development.

Gordon Goering, manager of the Ekofisk field, which is one-third owned by Phillips and in which the Bravo rig lies, refused to give any estimate of how much oil was skimmed off today. He would say only that one Norwegian skimmer had collected 20 tons, a small amount of the total spill, "in a short time."

Other officials acknowledged that there were "technical difficulties." One boom, for example, was found to be too short for the skimmer with which it was working. The successful Norwegian vessel was supposed to to be tested today for the first time; instead, this prototype was pressed into service.

It appears that the industry and the supervising governments have neglected investment in disaster equipment. As one specialist said, "It doesn't produce profits."

In the Norwegian Parliament today, the environment minister, Mrs. Harlem Brundtland, acknowledged that "The equipment so far had not been satisfactory and there was a risk of an oil disaster."

There is still considerable optimism that the Bravo blowout will not damage the coastlines - if the well is sealed soon. The slick is still a long way out at sea, 170 miles from the Norwegian coast.

One computer prediction is that 45 per cent of the oil will evaporate, another 30 per cent will sink and skimming should pick up about 20 per cent or a bit more. That would leave about 4 per cent drifting into shore.

Experts here, with an obvious interest in minimizing the Bravo episode, insist the spill is still far short of a catastrophe. For example, Bravo would have to gush 25 days to match the oil spill from the tanker Torrey Canyon off the coast of Britain and 100 days to equal the volume spewed up by a runaway well in the Santa Barbara channel.

Those events, moreover, happened inshore, creating the maximum damage to shorelines, wildlife and even fully grown fish. If the specialists here are right and the capping is completed soon, only a fraction of those volumes of oil will reach the Norwegian coast.

In any event, the oil will hit Norway's fish. Grim Berge of the Institute of Marine Research estimated that the oil already in the water will cause "low to medium" damage to fish larvae and eggs. The Ekofish field is in the center of the mackerel spawning grounds, and their spawning season begins in the middle of May. If the oil is still flowing then, the mackerel will be clearly endangered.

If the attempt to cap the well fails, Phillips plans to drill another well at the same spot to eliminate the pressure, but that is a long job, 30 to 60 days, according to experts.

Moreover, the rig assigned to this task has been immobilized by bad weather in Rotterdam and has not even begun to be towed to the site.