Pioneers of eco-drilling technology RWE Dea

PIONEERS OF ECO-

DRILLING TECHNOLOGY

RWE is one of Europe’s leading electricity and gas companies, and its subsidiary RWE Dea AG is responsible for Germany’s biggest and most productive oilfield; the Mittelplate oilfield located off the west coast of the German province of Schleswig-Holstein. Philip Yorke talked to Derek Moesche, RWE Dea’s press spokesman, about the new technology at work to protect this ecologically sensitive area, and the company’s solutions to optimise its off-shore drilling operations.

RWE is the top power producer in Germany, as well as being number two in the Netherlands and number three in the UK, with the market position in central and south-eastern Europe being expanded continuously. Through its subsidiary, RWE Dea, the group is successfully active in the business of gas and oil exploration and production in Europe, North Africa and the Caspian region. In addition RWE Supply & Trading is one of Europe’s leading energy trading companies. Today RWE Dea employs over 1360 people, and in 2010 recorded sales close to €1.4 billion.

Since the beginning of the exploitation of the Mittelplate field, RWE Dea AG and partner Wintershall Holding GmbH have produced more than 25 million mt of oil from the Dogger sandstone reservoirs. The hallmarks of the Mittelplate project are its technical innovations and safety concepts that are unique in the field of oil exploration and production. In the past 23 years, capital spending has reached almost €1 billion.

Exporting unique technology

The Mittelplate oilfield is situated in the Wattenmeer tidelands, an area which is one of Germany’s most unspoilt and cherished national parks on coastal tidal flats at the mouth of the River Elbe estuary. It is not surprising therefore that the most stringent efforts have been made to ensure the integrity and natural beauty of this site. RWE Dea’s safety and environmental protection record is second to none. The company’s highly sophisticated drilling, production and transportation concept has been continuously upgraded and employs unique drilling and recovery technology developed especially for the Mittelplate field.

Mr Moesche said, “Our expertise in drilling for natural resources dates back 112 years and as a result we are one of the most experienced oil and gas producers in the world. Our unique scour protection structure at Mittelplate made from riprap and mortar is continuously upgraded to meet the challenges posed by the natural shift of a tidal channel. This special location calls for the utmost care in the performance of all our operational activities. Many of the plant’s facilities were developed to provide and maintain reliable, impenetrable barriers to the Wattenmeer tidelands. In May 2010 we were granted an extended production permit for another 30 years.

“The drilling island is built as a compact, water and oilproof concrete-and-steel basin on top of the Mittelplate sandflats. From the island we pump the oil through a 10 kilometre pipeline, 7 kilometres to the mainland and continuing onshore for another 3 kilometres to the oil processing plant. Here, the oil is merged with onshore production from

GEO-data

GEO-data offers mudlogging services and a broad range of know-how around the geological/technical support of all kind of drilling activities. Recording, processing and evaluation of all surface logging data enhances safety and geological/technical understanding, thus leading to drilling optimizations which is our small contribution to the success story “Mittelplate”.

extended reach wells and separated into oil, gas, condensate and water. The hydrocarbons are treated to sales specifications and shipped via pipeline to local refineries.The land station covers 55,000 square metres and is designed to minimise the effects of the treatment facility.”

Multi-lateral well technology

For over 24 years and involving the continuous development of numerous innovations, RWE Dea in association with partner Wintershall has optimised drilling and production operations in the Mittelplate field. Twentyfive wells have been drilled into the western, larger part of the Mittelplate oil field since production began in 1987. These wells penetrate to a vertical depths of up to 3000 metres and are deviated in different directions – in some cases running horizontally through the reservoir to enhance production performance. A comprehensive, closed waste disposal system prevents contamination of the North Sea and the Wattenmeer tidelands during drilling operations.

Mr Moesche added, “We have developed and implemented in our last production well an unique, cutting-edge technology in drilling and completing our first multi-lateral well. This technology allows us to produce several reservoir targets from two branches in one well. The well was successfully put into production in October last year. Today we use our experiences in this innovative technology for our other international drilling projects. Our ‘leak-proof containerisation’ is unique in the world and we are using our shallow water expertise to best effect, e.g. in the Caspian Sea and the Egyptian Nile Delta. We are also utilising this specialised knowledge in other environmentally sensitive areas in our international core regions.”

In addition to the successful offshore operations at Mittelplate, the company has also been producing crude oil from the eastern parts of the oil field from facilities based on the mainland, via extreme, extended-reach production wells. These high-tech wells reach drilling lengths ranging from 7727 to 9275m, placing them in the list of the world’s most deviated and longest wells. Increasing production

Mittelplate has a record of more than 23 years’ incident-free production and in addition to the 25 million mt of crude oil that have already been produced, there are some 25 million mt of commercially recoverable reserves still available. As a result, not only is Mittelplate the German oil field with the highest production volume, holding 65 per cent of the national oil reserves, it is also one of the country’s few proven reserves with a long-term future.

The initial production rate of around 200,000 mt of crude oil in 1988 has steadily increased, so that by 2003 more than 2.2 million mt of crude oil was produced. In recent years, there has been a moderate naturally occurring decline in production. “Thanks to the sophisticated technologies we employ, we have been successful in countering the effects of this natural decline,” Mr Moesche said. The dynamic development of geophysical processes and drilling technology has opened up new horizons for RWE Dea. n