RWE along with its partners at German energy company Wintershall have worked to draw oil from the Mittelplate oil field since 1987. The 25 millionth ton of crude from the reservoir was extracted during the weekend, the company announced.
"With our successful and safe production operations in the Mittelplate oil field, we are making a contribution of our own to a secure supply from domestic sources," RWE Chief Executive Officer Thomas Rappuhn said in a statement.
The oil field accounts for more than 50 percent of the domestic crude reserves in Germany. RWE said it believes the field will remain significant as oil will likely be an "indispensable component" of a viable energy strategy for years to come.
Berlin in May extended the production permit for the oil field to 2041 based in assessments of the lifespan of Mittelplate.
"Given an expected natural decline of the production volume following many years of production, it can be assumed that it will be possible for oil to be successfully produced from this reservoir for a long period of time," the company said.