DANA Petroleum, the oil production company listed on the Irish exploration market, has completed its first programme of well-drilling in Siberia and has upgraded its estimate of probable reserves.

Through its Russian subsidiary YoganOil, Dana has completed the drilling of a new production well on its south Vat-Yoganskoye field. It is estimated that the well may have reserves of 500 to 1,000 barrels a day, according to the company.

This is more positive than estimates made in the last company prospectus. Drilling the well took less than one month and was ahead of schedule and under budget.

The company has just completed laying a pipeline to a number of wells at the field in Sportyskoye and tests have indicated probable reserves of 1,100 barrels a day.

The better-than-expected test results mean that more ventures between Dana and Russian oil companies are likely. Mr Tom Cross, the Dana chief executive, speaking to The Irish Times, said: "We are now exploring other exploration opportunities with the Russian companies we have been associated with, these could be in Russia or outside."

Dana has formed partnerships with three of the four biggest oil companies in Russia: Lucoil, Yukos Oil and Tyumen Oil.

The company intends to continue drilling at its two Siberian fields but all exploration work is now completed. Dana has four wells in production and hopes to add to that number by the end of thee Year.

Mr Cross said the markets may have to "re-appraise" the performance of Dana in the light of the positive drilling results.

The company reported a loss before tax of £678,006 in 1995 and was hoping this would improve because of activity at the Siberian fields.

Some of the wells have yet to be tested and production will not start on the new well in south Vat-Yoganskoye for another month. Dana is one of the few Western oil companies involved in the region.