While 3,000 top petroleum industry executives met here this week to chart their industry's future, demonstrators held their own meeting to attack ''profiteering Big Oil.''
Inside a downtown hotel, members attending the annual American Petroleum Institute (API) conference agreed that decontrolling natural gas prices immediately would duplicate the effects produced by last January's speeded-up decontrol of oil prices:
* Increased drilling for new supplies.
* Increased production from present wells.
* Increased energy conservation by consumers.
* Decreased reliance on overseas suppliers.
* Downward pressure on all energy prices, domestic and overseas, due to the first four effects.
To back up the argument for natural gas decontrol, the API (which includes natural gas producers) cites statistics showing that deregulation has led to an increased crude oil production in the lower-48 states for the first time in over 10 years. The increase is expected to continue, thanks to the petroleum industry's setting of all-time records for the number of seismic crews at work, rotary rigs in operation, and wells drilled and completed.
But in contrast to the 37.7 percent increase in domestic oil wells drilled during the first nine months of 1981 compared with last year, the number of gas wells drilled is up only 6.5 percent for the same period.
Decontrol natural gas prices now - rather than in 1985 - say the oilmen, and see a revitalization which will both spur new gas drilling and benefit the US economy as a whole.
Consumer groups, however, want natural gas decontrol postponed rather than speeded up. They charge that decontrol could double winter heating costs for many families at a time when federal budget cuts are already making the poor poorer. Under a variety of trade union and consumer group banners, angry demonstrators outside the API conference chanted ''Freeze prices, not people.''
The industry estimates that immediate natural gas price decontrol could raise the wellhead price from an average $1.80 per thousand cubic feet to $4.10. This hike would be offset by eliminating the vast differences in current wellhead prices, which range from 40 cents to $9 per thousand cubic feet. The wide price spread is based on a costly network of government regulation. Along with the cost of regulation itself, many feel that the artificial price differentials can encourage illegal practices.