The quorum bells ring, weary senators shuffle onto the floor venting their irritation at the antique process known as a filibuster. In the midst of this uproar one figure stands serene and unmoved. This is not Horatius at the bridge holding off the vandals bent on destroying the temple of free enterprise. It is Horatius who owns the bridge.

Sen. Russell Long (D-La.) may not be the richest man in the Club of One Hundred but it is a safe guess that he has more oil and gas interests than any of the others. Elected first to the Senate in 1948, he has for more than a decade been chairman of the Senate Finance Committee.

In the post, one of the most powerful in the Congress, he has been able to hold off with tactics of delay and obfuscation all attempts to disrupt the big oil companies with their grip on every phase of the energy quotient. Doesn't this sound like conflict of interest, so often bandied about when someone in the executive branch is surprised with his hand in the cookie jar?

Not so at all, say Long's loyal aides. The senator represents Louisiana, which is the second largest producer of oil and gas in the nation. That is his identity, and he points with pride to the fact that Louisiana's oil and gas severance tax supplies up to one-third of the state's revenues. This is one reason property and other taxes are so low in the state the Longs built.

It is an extraordinary story. When Russell's father, Huey, was assassinated in 1935 on the steps of the capitol in Baton Rouge, Russell was 16 years old. He had seen his dynamic father rise from governor to senator, challenging the hold of President Franklin Roosevelt on the South, and, as the Kingfish, proclaiming his share-the-wealth program.

Huey had done a lot to break the hold of the Bourbon hierarchy in New Orleans and bypass the rutted red clay roads with modern highways. In the process of making Louisiana his personal fiefdom, he managed to accumulate considerable pelf - a part of which included the Win or Lose Oil Company.

After World War II, Win or Lose was broken up and its valuable oil and gas leases sold to various oil companies. That is the basis of the senator's fortune. How large it is only the senator knows, and he isn't telling. A reporter suggested to John Steen, Long's press aide, that it was somewhere in the range of $50 million to $100 million. Steen laughed politely (it was a woman reporter) and said the Long holdings were not even a fraction of that estimate.

Having been reelected four times, Long at 59 can go on until he's 100 if he chooses to. And given the entrenched system of committee chairmanships, he can continue to hold the key position, checkmating not only inroads on the domain of oil, but other raids on the private power structure as well.

As the Senate proceeds to tear the Carter energy proposal to pieces, Chairman Long has hardly had to lift a finger. The initial proposal was not very strong on the side of conservation and price control over gas and oil. But as it comes out of the congressional shredding machine, it promises to be less than that - unless the Senate conferees yield in some degree to the House, which passed a measure nearer the administration's prescription.

A long time ago, or so it seems now, Carter called the energy contest the moral equivalent of war. His appeal for voluntary conservation has gone unheeded as the rocketing increase in the use of gasoline - now said to be in plentiful supply - goes right on.

Voices are raised pointing to the inevitable crunch ahead, in view of the reliance on imported oil. One such voice is "Rays of Hope" by Denis Hayes of the World Watch Institute. He believes solar energy is the only alternative in the transition to a post-Petroleum world. Solar energy is still in the experimental stage, with little evidence of any change in the near future of a shift away from oil and gas.

Win or Lose? Brother, you can't lose. The present governor, Edwin M. Edwards, in the Louisiana Hayride tradition, who took Korean money by way of a "gift" to his wife, went so far not long ago as to suggest that the state might just cut off the export of oil and gas to the mean, niggling oil North.

Russell served at the start of his career as an assistant to Uncle Earl Long, governor for more years than anyone in the history of the state. Once when the outer office was full of reporters complaining about the discrepancy between Earl's rhetoric and his performance, Russell went in to ask him what he should do. "Why just go out there and tell 'em I lied, that's all, I lied." This useful formula is one that Russell has never had to fall back on.