The Wietze drilling department, part of drilling and production engineering at the Hamburg headquarters of German operator RWE Dea AG, owns and operates two rigs in addition to those leased from drilling contractors. The powerful (6,500 hp) T-160 rig has a 580-tonne maximum hook load capacity and runs on DC power generated by three Caterpillar 12-cylinder diesel engines. The low-noise rig features sound-insulated power equipment, pumps, and hoist.
Wietze began operating the T-160 rig in 1997 and uses it to drill up to two gas wells/year in Lower Saxony, the center of Germany’s gas production. According to statements made at RWE Dea’s annual press conference on Mar. 2, 2005, Wietze spudded the Völkersen Z7 production well in August 2004 and expected to reach the 5,000 m TD of the Völkersen-Nord Z5 in May 2005. The company’s Lilienthal-Sud Z1 exploration well near Bremen, drilled in fall 2004, was unsuccessful.
The Minister-President of Germany’s Lower Saxony, Christian Wulff, said in an Apr. 15, 2005, press release that “about 20% of Germany’s demand for natural gas is met by domestic sources, “and this comes predominantly from the natural gas supplier state of Lower Saxony.” Wulff was visiting an RWE dea drill site where the T-160 drill rig was at work on the Völkersen-Nord Z5 natural gas well near Verden (Fig. 3). RWE Dea has produced about 8 billion cu m of natural gas from the Völkersen gas field (2 billion in 2004).
Wietze’s second rig, the T 345, was used for extended reach drilling (ERD) in Germany’s Mittelplate oil field. The rig was permanently installed on the 70 x 95 m Mittelplate drilling and production island in the southern part of the Wattenmeer National Park in the North German state of Schleswig-Holstein. In 2004 and first-quarter 2005, the rig drilled the Mittelplate A17 and A18 wells.
At the Mar. 2 press conference, RWE Dea announced progress on a new drilling rig for Mittelplate from Bentec GMBH Drilling & Oilfield Systems, based in Bad Bentheim. The T-150 derrick will be commissioned by the end of 2005 and will enable wells to target prospects within a 6-km radius around the island.
ERD wells have been drilled into the eastern part of the Mittelplate field from onshore sites at Friedrichskoog and produced into Dieksand. Drilling to 2,000 m deep with 8,000 m step-outs (longest TD was 9,275 m, Dieksand 6 well), these are among Europe’s longest ERD projects.
