The 11 largest U.S. oil companies, using a controversial new accounting technique insisted upon by the Securities and Exchange Commission, estimate that the present value of the future flow of cash from their oil and gas reserves rose last year by $95.1 billion to reach $227.8 billion.

The enormous jump in expected future revenues from their oil and gas in the ground is probably understated, since the estimates assume no further rise in oil and gas prices. However, taxes -- in some instances very large ones -- will have to be paid on these revenues.

The huge increase is a major reason, along with the more highly publizied and much criticized increases in 1979 oil company earnings, that oil company stocks have shot up in value in the last 15 months. The aggregate value of the common stock of the 11 companies rose $48.7 billion between the end of 1978 and last week.

Meanwhile, their first-quarter 1980 earnings more than doubled compared to last year, reflecting the OPEC-led 127 percent increase in world oil prices.

Even stock market anaylysts say that, based on the oil and gas reserves of the campanies and the prospect of future earnings from them, their stock prices should be much higher. They are not, the analysts say, because investors fear governments in the United States and elsewhere will tax away an even larger portion of those future earnings.

The stock of some of the 11 companies, each of which had sales of more than $10 billion last year, has risen much more rapidly than others, with Mobil leading the pack.

The price of a share of Mobil, which has had several impressive new finds of oil and gas off the east coast of Canada, in the North Sea and elsewhere, has more than doubled since the end of 1978, splitting two for one in the process.

That price jump prompted Rawleigh Warner Jr., Chairman of Mobil, to excercise stock options he held from prior years that netted him $3,125,850 between the end of 1978 and Feb. 8, 1980, according to a Mobil proxy statement. Adding Warner's 1979 salary and bonuses totaling $1,187,055 made him one of the most highly paid executives of any U.S. corporation.

The oil company reports to the SEC on the value of their oil and gas reserves are full of disclaimers -- and for good reason. Estimating the amount of oil or gas that a particular field contains is, one industry executive puts it, an "engineering art, not a science."

Once the company has an estimate of how much oil or gas a field has, it has to make a further guess about how much of it can be brought to the surface, since all of it can never be recovered. To comply with the SEC reporting requirements, further estimates of the timing of production -- whether this year, or 10 years from now -- must be made, along with other calculations about future development and production costs.

The company, at the SEC's direction, generally assumes prices and costs will remain unchanged from what they were at the end of 1979. Cranking in the rate, costs and timing of production gives a figure for future revenues year by year.

Then comes the final wrinkle, something called discounting. As everybody knows, a dollar you get next year is worth less to you than a dollar you have today even if there were no inflation. That's because if you have the dollar now, you can buy something with it and use it immediately, or perhaps invest it and receive interest or dividends.

Therefore, revenue from oil and gas produced in 1981 or 1985 is considered worth less to a company now than oil and gas it will produce and sell in 1980. The SEC directed the companies to discount those future revenues at the rate of 10 percent at Year.

The result is probably an extremely conservative estimate of how much the value of the companies' oil and gas reserves changed during 1979.

The $95.1 billion increase recorded by the 11 companies, for instance, reflects very little of the effects of the phased decontrol of domestic crude oil prices.

Since all of the big companies area also major refiners and marketers, having their own crude supplies can be the key to making money on those operations.

This is one reason that some of the oil giants have been paying enormous prices for smaller oil companies -- to get their hands on these companies' reserves.

The name of the game is reserves, and the prerequisites that can lead to them: a good "land" position and an aggressive and successful exploration program.

Standard Oil Co. of California, the No. 4 oil major, and Standard Oil Co. (Indiana), the sixth biggest, are credited with both by industry analysts. Socal's stock price has sky-rocketed 170 percent since the end of 1978, though the total market value of its common stock has risen less than that of larger Mobil. Standard of Indiana, which has made several strikes in the Overthrust Belt of Utah and Wyoming, has seen its stock value jump nearly 80 percent.

On the other hand, notes analyst Charles Maxwell of Cyrus J. Lawrence, an institutional research firm, "Exxon, which has had no big exploration stories and was not desperately undervalued" has gone up far less in value, only about 23 percent.

All of the oil industry executives object to the new SEC disclosures requirements, which are called reserve recognigtion accounting, or RRA for short. One every page of the section of Mobil's annual 10-K report to the SEC that deals with RRA, it printed a warning: "Mobil cautions investors and analysts against simplistic use of Secton J data."

What really upsets Lause and his counterparts, such as David Welch at Conoco, is another aspect of RRA that, for 1979, presents a radically different picture of what happened to the big oil companies.

Under RRA, the companies had to calculate their earnings -- again on an unaudited and experimental basis -- counting as income any changes in the value of their reserves. Normally, income from a business activity is recognized only when it is received. But under RRA, income would be recorded when new reserves were found or old ones increased in value, and all the costs of finding the oil and gas would be deducted as an expense immediately.

On the basis of conventional accounting, the 11 oil companies earned $17.1 billion after taxes from all of their business activities, including refining and marketing, petrochemicals, coal and a host of other enterprises ranging from shipbuilding to department stores.

On the basis of reserve recognition accounting, however, the companies earned $53.7 billion after taxes -- or more than three times as much.