In 1991, in a collaborative venture under the auspices of the DTI, GEC-Marconi developed a test-bed Autonomous Underwater Vehicle. In line with the tenets of the CRINE initiative this vehicle is currently being developed (through JIP funding) to undertake autonomous oilfield pipeline survey missions, with minimal weather dependence and without the need for surface support vessels. This paper reviews the available AUV sub-system technology and described the aims and activities of the current project.
The North Sea represents a mature hydrocarbon production asset with an extensive infrastructure of major trunklines, interfiled pipelines and intrafield flowlines. The integrity of this vital hydrocarbon transportation system is monitored by the Operators through surveys specified by "in-house" procedures and statutory regulations. These surveys are currently executed by surface vessels deploying ROVs or towed instrumentation arrays.
Over the last few years considerable non "oil and gas" related research effort has been expended to successfully develop Autonomous Underwater Vehicles (AUVs) for oceanographic data gathering on the continental shelf and in specialized military applications. This work (now aimed primarily at extended "cross ocean" missions in ultra deep water) continues, but the technological know-how generated could be adapted for the less onerous task of subsea hydrocarbon pipeline survey.
In the spirit of CRINE (Cost Reduction Initiative for the New Era) a Joint Industry Project (JIP) has been initiated with the aim of defining, developing, testing and bringing to the market place an autonomous (free swimming) pipeline survey vehicle.
By launching (and recovering) the survey AUV from the offshore platform (or pipeline landfall) the requirement for surface support vessels and associated weather downtime is eliminated. This provides an opportunity to achieve a substantial reduction in operating costs.
The JIP itself is perhaps unique in that it is neither a paper exercise nor a high cost hardware development programme. The bas vehicle has been built and tested by GEV-Marconi Naval Systems Ltd., and is being made available to the project. Work will therefore centre on the attainable and specifically defined goals of optimising offshore launch and recovery, and navigation techniques, and selecting suitable data gathering instrumentation.
The following paper details the project aims and activities and discusses possible future developments.
GEC-Marconi Naval Systems Ltd are the UK's leading naval weapons research and development contractor dealing primarily in advanced torpedo technology.
In 1991, in a collaborative venture under the auspices of the Department of Trade and Industry, the company allocated substantial funds to initiate work on the design and construction of an Autonomous Underwater Vehicle to be used as a test-bed for oceanographic instrumentation packages for long range missions.
The resulting vehicle system, ODAS (ocean Data Acquisition System, ref. fig 1), has been extensively tested and refined and is now available to be tailored to specific mission requirements. In bringing this technology to the offshore industry annual pipeline integrity surveys are seen as being a suitable "first step" task for the AUV systems.