The Eems estuary forms part of the Dutch/German border on the North Sea coast of Northern Europe. Gas productionbplatforms have been a common sight in the estuary for many years, one such platform being the Emshorn ZIA platform which lies central to estuary and provides gas to Groothusen-Sammel station in Germany. With gas production from this platform nearing the end of its useful life it was decided to construct a new platform, Manslagt ZI some distance to the southeast of the Emshorn platform.
As may be expected with a marine-based project, the geology of the route needed to be well understood in advance of the commencement of drilling operations. To achieve this knowledge, detaile d investigations including cone penetration tests at five locations and one borehole to reference the cone tests were carried out. In parallel with these investigations a geoelectrical soil survey was also completed using a trailing wire technique. The results of these surveys showed that ground conditions, to a depth of 20 m below the sea bed, the depth to which the bore was scheduled to run, comprised consolidated sandy/clay material overlain by unconsolidated river silts.