Will 'seven sheikhs' replace 'seven sisters'?

As OPEC struggles to prevent a dramatic collapse of oil prices, the oil world is talking about a new long-range development that promises to help consumers . . . and undercut the ''seven sister'' major oil companies at the gas pump.

The development is that one Arab member of the Organization of Petroleum Exporting Countries, Kuwait, has moved out in front of its rivals and decided not only to extract oil from the ground, but also to refine it and to sell it to the consumer.

Until now, Americans and Europeans have seen the familiar names of the ''seven sisters'' on their gas pumps and on their home heating trucks - Mobil, Shell, Exxon, and the rest - or the names of smaller independents such as Conoco.

In recent weeks, the Gulf state of Kuwait has bought refineries and gas stations in the Benelux countries (Belgium, the Netherlands, and Luxembourg), plus a reported 544 gas stations in Sweden and 274 stations in Denmark from another Gulf entity - the US Gulf Oil Company.

For a while, it is understood, the name ''Gulf'' will stay on the signs. Eventually, another brand name - ''Arab oil''? ''Burnoose''? - will be painted over them, and there are some experts here who see a new era approaching as other producers are tempted to follow.

The Kuwaiti move is highly controversial, and it faces many obstacles. It represents the thin edge of a wedge that major oil companies have been eager to block altogether: an Arab producer that can extract its own oil cheaply can afford to undercut any price at the pump that a major oil company can post.

The major companies stress the difficulties of balancing supply and demand. They say the Kuwaitis lack expertise and experience. Their big worry is that other producers will follow Kuwait's example - and the ''seven sisters'' will be beaten at the pumps by the ''seven sheikhs,'' or some other combination of OPEC producers.

On the other hand, a number of oil analysts here agree the Kuwaitis are shrewd to begin doing more than drilling and exporting.

''The Kuwaitis,'' observed Dr. Paul Stevens, lecturer in oil economics at the University of Surrey, in an interview, ''are greater realists than a lot of other oil producers. . . . More farsighted.''

Another oil analyst in the City of London says, ''The Kuwaiti move had to come at some point. Oil prices are falling and OPEC has to find extra ways of making money.

''The Kuwaitis can afford to cut prices, take losses for a while, and end up with a significant share of the market in Europe. Everyone will be watching them. . . .''

Kuwait's first move was to buy Gulf Oil's Rotterdam refinery and Benelux trading network in a deal reported to have been worth $150 million. Another report says Kuwait paid not in cash but in deliveries of oil. Gulf is moving back to the US, having incurred losses in the competitive European market.

The second Kuwaiti deal is said to involve the equivalent of $200 million for gas stations in Sweden (believed to sell 10 percent of the petroleum products there) and Denmark (7 percent), as well as a refinery in Denmark.

Experts, including Dr. Stevens, say the Kuwaitis have had longer experience than their neighbors in earning extremely high oil revenues per head of population - since the mid 1950s, in fact.

The Kuwaitis have also been quicker than others to see the need to refine their own crude oil at home for export. Two weeks ago, industry sources report, Kuwait's exports of crude oil were down to about 140,000 barrels per day (b.p.d.), whereas its ''product sales'' were up around 500,000 b.p.d.

OPEC as a body has long had a policy of moving ''downstream,'' say its spokesmen in Vienna. But it hasn't moved far. It is difficult and expensive to build and run refineries in developing countries.

But efforts continue: The Saudis are building two more large refineries, with Western help. The new export refinery in Libya, Ras Lanuf, has been delayed. Algeria started up an even bigger refinery at Skikda two years ago.

But Kuwait is the first producer to buy refineries and gas stations abroad. ''The major oil companies are right to be afraid,'' says one leading analyst here.

''The move will eventually fail,'' predicts one oil company official. ''The Arabs will join them and they will all argue about prices as hard downstream as they do now upstream, over crude oil.''

''Don't be so sure,'' warns yet another analyst. ''The seven sisters are vulnerable now that they don't control their own crude oil anymore.''