French oil major Total and its project partners installed a Long BaseLine (LBL) acoustic positioning network, using the Sonardyne Fusion 6G technology, at Kaombo oil field offshore Angola.
The campaign to deploy, calibrate and make ready for work the field-wide array of transponder frames, was completed in just 31 days using the seabed component of a Fusion 6G system, Sonardyne reported.
Technip in France held the project planning workshops for the deployment of Fusion 6G at Kaombo. Attended by teams from Total, Technip and Fugro, together with personnel from Sonardyne’s Survey Support Group (SSG), the sessions were used to review the full scale of the operation and consider the most efficient and cost-effective configuration of the LBL transponder frame network.
Technip conducted the LBL array planning, a process that involved confirming that there was clear line of sight between neighbouring transponders and modelling acoustic network coverage at specific locations, the company noted.
Commenting on this, Regis Mortier, Senior Survey Consultant at Technip, France said, “Besides Sonardyne’s expertise and field proven subsea technology, there were a number of innovative firsts that paved the way for quick and efficient equipment deployment at Kaombo. The use of stackable frames optimised deck space, saving time as we only had to use one vessel and make one trip out to the field. In addition, our innovative spreader bar meant we could deploy five frames in one sequence, thereby speeding up overall frame and Compatt deployment.”
Steven Tonneman, Project Co-ordinator at Fugro Survey B.V. said, “The use of Technip’s two work-class ROVs operating concurrently in the field meant that we could simultaneously deploy, calibrate and move Compatts on the fly. Starfix.Acoustics, a Fugro specific variant of Fusion 6G, batched simultaneous baseline collection feature, allowed data to be gathered during deployment operations and win back vessel time. Post deployment, the sound velocity data gathered by the Compatts meant that our calibration results met Total’s very stringent specifications.”
Also commenting on the project, Frederic Auger, Chief Surveyor at Total E&P said, “We can’t fault the preparation and professionalism displayed by all personnel involved with this massive project. With future time savings gained from not having to deploy many individual transponder arrays, the cost of installing a field-wide LBL permanent frame network that can be scaled from high accuracy metrology to LBL aided inertial and also LUSBL positioning for DP and drilling, means this investment will more than pay for itself within the first few years of the field development.”
From a Sonardyne perspective, Tom Bailey, Acoustics Surveyor, said, “The SSG is frequently asked to assist with many different aspects of offshore survey campaigns. On this occasion we were involved in the planning stages and in the post project wash-up workshop. It’s been very rewarding to see such a well organised and executed project successfully achieve its aims and exceed expectations.”
Kaombo field lies in water depths up to 1,750 metres offshore Angola. Development of the field will involve the drilling of 59 subsea wells, connected by over 290 kilometres of subsea lines leading to two floating production, storage and offloading (FPSO) vessels. The majority of subsea construction work is scheduled for 2016-2017, which will be supported by the permanent transponder frame network.
First oil for the initial FPSO is expected in 2017, with production from the other two FPSOs likely to reach an average of 230,000 barrels per day in normal operating conditions out of an estimated reserve of 660 million barrels.