First Deployment of the Underwater Drill Rig MeBo200 in the North Sea and its Applications for the Geotechnical Exploration

Abstract

Abstract As the drilling technology has advanced, recent deepwater developments and explorations are currently taking place in Gulf of Mexico, Brazil and West Africa where deeper reserves of oil have become more accessible. The study of the subsea soil (e.g. soil investigation, positioning foundation design) is one of the activities required for the subsea field development. Electromagnetic tests, CPT tests, gravity, piston core or vibrocore samples are obtained by deploying down-hole systems from drilling vessels. However, because of the high costs and low availability of drill ships, and because ship and drill-string motion due to wind, currents and waves affect the quality of the drilling process, robotic drill rigs are currently more widely used. The following paper describes the MeBo200 as a novel underwater drill rig for geotechnical/geological explorations. The MeBo200 drilling rig is lowered to the sea floor and operated remotely from the ship to drill up to 200m into the sea floor at an ambient pressure of up to 400bar. It was developed in cooperation by MARUM Center for Marine Environmental Sciences (University of Bremen) and BAUER Maschinen GmbH. The complete system is transported within seven 20 ft containers. MeBo200 is a second generation of the MeBo, which was the first remote-controlled deep sea drill rig that uses a wireline coring technique. The weight of the MeBo200 is about 10 tons in air and 8 tons in water and therefore it does not need special drill ships to be managed reducing therefore the mobilization costs for worldwide deployment. The MeBo200 was deployed in the German sector of the North Sea in October 2014 to test the functionality of the seabed-based drill rig. Currently MeBo200 is being upgraded with CPT technology from A.P. van den Berg Ingenieursburo bv.