French oil major Total, operator for the Egina oil field offshore Nigeria, together with its construction and survey partners, has successfully installed a Fusion 6G subsea positioning network to support its development of the $15 billion project. Supplied by Sonardyne International Ltd, UK, the acoustic technology specified for Egina, which is still ongoing, included a field-wide array of Compatt 6 seabed transponders that were deployed and made ready for work eight days ahead of schedule.
Located 150 kilometres off the coast of Nigera, in water depths of up to 1,750 metres, the Egina field covers an area of around 500 square miles. Infrastructure will include an FPSO, an oil offloading terminal and subsea production systems that will included 52 kilometres of oil and water injection flowlines, 12 flexible jumpers, 20 kilometres of gas export pipelines, 80 kilometres of umbilicals, and subsea manifolds. Production at the field is expected to reach 200,000 barrels per day at its peak.
Fusion 6G is Sonardyne’s sixth generation of Long BaseLine (LBL) acoustic positioning system, and is widely considered the industry standard tool for subsea construction and survey thanks to its performance and time saving features. Using Fusion 6G, major tasks such as structure installation, spoolpiece metrology, ROV tracking and route surveys can be completed quickly, reliably and accurately in any water depth.
Planning for Fusion’s deployment at Egina had begun several months earlier and involved senior project managers and surveyors from Total and its sub-contractors, working closely with personnel from Sonardyne’s own Survey Support Group (SSG). The SGG is a specialist department staffed by experienced offshore personnel, each of whom also possess unique knowledge of Sonardyne’s acoustic and inertial navigation technologies and how best to configure them for any given scenario.
The work undertaken by the SGG for Egina included analysing the proposed location for each of the Compatt transponders in the seabed network, and in doing so, verify that there was clear line of sight between each transponder in order that they can reliably range to each other. In addition, the SSG team mapped out seabed coverage and the expected positioning performance of the Compatts at all points of interest. This essential process involves specialist software and also helps to identify the optimum quantity of transponders that are needed to meet a project’s positioning specification.
At Egina, the investment in time planning acoustic operations onshore, was rewarded with a highly successful offshore LBL campaign. The wide-area transponder array was deployed, installed and calibrated more than a week ahead of schedule and without any further direct support from Sonardyne and the SSG.
“The array installation and subsequent UFR campaign performed at the Egina field, has proven to be an extremely successful demonstration of Fusion’s capabilities. Off the back of it, we will be using it to support ongoing field construction activities throughout the rest of this year and into the 2016 season.” He added, “The system’s quick setup and deployment, meant that the savings in vessel time alone has more than justified our decision to trust in Sonardyne’s low-risk digital technology platform.”
“The successful results we’ve seen at Egina, echo those from similar projects around the world. Fusion 6G saves time, lowers risk and delivers operational cost savings – something that is on every ones’ minds more than ever at the moment. Egina serves as another great example of how planning, rehearsal and training leads to operational success.”
For more information about Fusion LBL click here