25 Years of Operating Germany's Largest Oilfield Mittelplate: Applying the Experience to Exploratory Drilling in a National Park which is an UNESCO World Natural Heritage Site

Abstract

Abstract Germany’s largest oilfield Mittelplate is located in the tidal flats of the Wadden Sea off the North Sea coast. In 1985 this unique area was designated as a National Park and was awarded the status of an UNESCO World Heritage Site in 2009. To meet the conditions of this ecologically sensitive tidal region an artificial drilling and production island - Mittelplate A was designed and installed about 7 km off the coast. Since the start of production in 1987 innovative and unusual technological solutions were a prerequisite for achieving safe, environmentally compatible development of the Mittelplate oil reservoir. 25 years of incident-free operations show that the sensitive ecosystem is not impacted by any work being carried out. Sophisticated monitoring and control systems and the deployment of experienced, responsible specialists ensure safe and environmentally friendly drilling and production operations with highest quality. Of key importance are open discussions with the competent authorities, the National Parks Board, nature conservation and environmental associations, the municipalities and other stakeholders, e.g. NGOs. Additional oil reserve potential has been identified in the vicinity and south of Mittelplate oilfield which needs to be explored by drilling four wells in the National Park environment. A Wadden Sea Exploration Project has been set up and the experience of the Mittelplate operation will be utilized during all phases of this campaign, i.e. engineering, approval, construction and operations. The exploratory drilling will be performed with a special designed barge based drilling rig setup. As conventional production tests are not allowed an extended logging and sampling program will be executed in case of discoveries. Afterwards the wells will be plugged and abandoned and the four drilling sites will be completely restored. In case of commercial discovery the reserves will be developed either from the existing Mittelplate A facilities or from onshore with Extended Reach Drilling up to 15 km TD.