In the flat, serene pastures that envelop this town near the North Sea, over 300 wells pump out the presious methane gas that sustains Dutch affluence and arouses the envy of a continent stuck with high oil bills and scant resources.

But like the Dutch fairy tales that often carry harbingers of gloom, the good times may be coming to an end. Unless major new fields are discovered in the next decade, Holland's lucrative natural gas exports will cease by 1992 and all known reserves will be exhausted by the turn of the century.

"The outlook is bad," said Ton Oosterbaan, an official at Nederlandse Gasunie Co. here, which markets the country's fuel largesse. "Demand keeps rising and fields keep shrinking."

Once the hapless victim of an Arab oil embargo that posed a crippling threat to its huge refineries, the Netherlands has earned windfall profits from the energy crisis in recent years by shrewdly indexing the price of natural gas to that of oil.

Since 1973, the Dutch government, which pockets 90 per cent of the profits from natural gas sales, has matched each hike in oil prices with an equivalent increase in gas prices. The linkage was intended to ease Holland's oil payments burden but also to reduce depletion of gas reserves.

Faced with diminishing gas reserves and the alternative of costly oil, the Dutch have embarked on rigorous conservation measures. Houses are being insulated, bicycles are more popular than ever and even windmills are being restored as ways to cut energy costs.

Environmental groups have argued for more judicious use of the country's natural gas resources, including a more frugal policy toward exports.

Last year, the Netherlands produced 94.3 billion cubic meters of natural gas and shipped 54 per cent abroad, mostly to Germany, Belgium, France and Italy. Export sales reaped nearly $3.5 billion, covering a little more than half the nation's oil import bill.

Holland's vast natural gas fields have protected the economy from the ill effects of a lingering world recession that struck West European countries, hurt by a penury of energy resources, especially hard.

The gas exports kept the Dutch economy strong during a period when rising costs in labor and raw materials squeezed Dutch companies in foreign markets.

"We don't know how long it will be before the buble burst," said Harry Oosting, who works in Assen for the state-run firm that explores new gas fields. "We have lived so long on the large gas reserves that it seems difficult to realize only small amounts will be found from now on."

Natural gas accounts for 55 per cent of all the energy consumed by the Dutch people. It heats their homes and appliances, powers their factories, and even fuels some of their vechicles.

That proportion, however, will probably drop as low as 30 per cent in the next ten years. The lure of eager foreign buyers, as well as Dutch people committed to using natural gas, is expected to drain Dutch gas reserves as long as oil remains expensive.