deeper and deeper offshore as well as ice-covered arctic waters. The current focus is on innovation in techniques and materials that enable human access to those ever-more difficult targets. A prime example is the Swimmer system for which Cybernetix, Statoil and Total initiated a feasibility study in 2007. After 18 months, Total decided to study further the Swimmer concept for the offshore Angolan specific application. Swimmer is a vehicle that performs inspection, maintenance and repair of subsea production systems with enhanced versatility and responsiveness. It is a hybrid system composed of an AUV (Autonomous Underwater Vehicle) and a ROV (Remotely Operated Vehicle). As such, it can perform pipeline inspections in AUV mode and light interventions on subsea equipment by deploying its own embedded ROV operated from topside production facilities. This innovative vehicle is designed to reduce operational risks as well as operating costs as it does not call anymore for a ROVsupport vessels. It is engineered to remain on the seafloor for up to three months at a time, without any need for maintenance. Swimmer is undergoing further development to meet tomorrow s challenges - including deployment in arctic regions.
. Subsea intervention system for arctic and harsh weather
is a new hybrid AUV / ROV subsea intervention system for light inspection, maintenance, and repair (IMR) operations on subsea production systems (SPS). One prime advantage is that it can carry out IMR operations on its own, without a field support vessel. Once the Swimmer AUV shuttle is resting on its docking station, the ROV can be controlled fully from surface facilities via the production control umbilical. The Swimmer s technical feasibility was shown in 2001 by full-scale sea trials. Since 2007, Total, Statoil, and Cybernetix have cooperated to develop a commercial version. Although the first application of this technology is earmarked for Total s Angola block 17 in late 2011, the partners are investigating use of the Swimmer system in offshore fields with extreme weather conditions. Swimmer not only can boost the flexibility and reduce the cost of operations for deep offshore fields, but also may become an enabling technology on ice covered arctic fields or in harsh environments such as the North Sea. The weather at these fields can prevent intervention vessels from operating for long periods, and is a personnel safety concern. In these conditions, the Swimmer s ability to remain deployed subsea for several consecutive weeks is a key point for the operability and maintenance of such fields. For arctic regions, operations during ice formation and ice thickness may require an expensive icebreaker vessel. Drifting icebergs also threaten support vessels and production facilities. Sea state for some harsh environment areas may exceed Level 7 during parts of the year, making deployment and recovery of subsea intervention vehicles dangerous. Swimmer can be a tool to operate and or maintain subsea production assets when infrastructure is not reachable from the surface.CONCEPTprime advantage of swimmer is its capability to operate on its own, without a dedicated multiservice vessel (MSV). The AUV part of the hybrid vehicle, the so-called AUV shuttle, ideally is launched from surface production facilities or a vessel of opportunity, and programmed to navigate autonomously to a subsea docking stati...
