Subsea Work With Robots in Hyperbaric Environments

摘要

ABSTRACT The work presently reported is part of a comprehensive underwater technology R+D-program at GKSS. A special subject in this program is the development of advanced robots applicable for hyperbaric dry and wet environments in order to mechanize subsea work. As a first step in this program modified industrial robots are used for working processes in a pressurized chamber, which simulates the hyperbaric dry ambient conditions of an underwater habitat up to 110 bar. The performed tests have shown reliable functions, of the modified robots and of the auxiliary equipment and indicated the feasibility to mechanize offshore-relevant working procedures like welding and jet cutting of steel plates under the severe conditions of a pressurized inert gas atmosphere. This development opens a new field of robot application for subsea work in order to assist and later on to replace divers and thereby to reduce human subsea intervention. INTRODUCTION The exploitation of oil and gas reserves offshore progressing to greater water depths directs to the need for developments towards the automation of underwater techniques. This is especially indicated by the works at the Norwegian Troll field down to 450 msw, in the Gulf of Mexico down to 530 msw, in the Mediterranean Sea at Montanazo to 760 msw and in the Campos Basin at the east coast of Brazil down to about 2000 msw. As the water depth increases beyond 500 m and towards 2000 m, diverless technology like robotics becomes more and more mature, considering economical aspects in offshore activities like safety for men, cost effectiveness and independence of seastate conditions. In order to meet these future requirements, at GKSS the application of modified industrial robots for subsea work under hyperbaric dry and wet' conditions up to 110 bar is under research. Main working processes to be mechanized in the first step of this development are IRM- (Inspection, Repair and Maintenance) operations. To qualify the robots for this subsea work and to test their functions in hyperbaric environments the GKSS-Underwater- Simulator GUSI is available, which allows to avoid expensive offshore tests. The pressure chambers of GUSI make it possible to simulate offshore-relevant hyperbaric dry and wet conditions for saturation dives down to 600 msw and unmanned tests with sensor guided and remotely operated handling systems down to 2200 msw. AVAILABLE ROBOTS AND MODIFICATIONS At GKSS currently two modified robot types are available, which are adapted for operations in gas atmosphere to a pressure of 120 bar. Their working places are in the pressure chambers of GUSI, which simulate in this case the boundary conditions of an underwater habitat to perform tasks like cleaning, non-destructive testing, jet cutting with abrasives and welding of offshore-like materials and components.