We've been there, We've done It!
Our Buoy Solutions technology is designed as a production vehicle, not a single use production monument.
Ocean’s Autonomous Buoy Systems can easily be removed, refitted and redeployed eliminating expensive decommissioning costs and amortising the system costs over multiple field applications.
This further reduces project risk and project development costs increasing the technology’s competitive advantage and changing the game in relation to sub-economic developments.
The Sea Commander buoy design has been approved for use in the United Kingdom, Australia and the Republic of South Africa for specific field control and power buoy applications.
In-depth discussions have also been held with the Norwegian Petroleum Directorate and no specific technical issues are envisaged with its use in that jurisdiction.
Extensive discussions have also been held with the UK HSE in relation to the development of the Sea Producer autonomous production buoy and again no insurmountable technical issues are envisaged with the design concept.
As part of the approval process for the CNR Power Buoy it was required to submit the Ocean design to full safety case review which satisfactorily covered all relevant safety and operational considerations for the Power Buoy facility and its integration into its host platform's systems.
All buoy systems designed by Ocean fully comply with the requirements of any required field development safety case.
DNV Technology Review
Ocean commissioned a specific technical review relating to its autonomous production buoy system (Sea Producer). DNV carried out the review and concluded that the system was technically viable in all technical areas.
Field Control/Supervision• Remote Chemical Injection
A proven concept with real and successful operating record in hostile waters for between 12 years and 15 years each unit!
Sea Commander is an autonomous self-powered field control buoy that can fully control any subsea oil or gas field providing real time monitoring, chemical injection, remote pigging, pipeline/flowline heating and equipment operation (including subsea trees). It will provide a fully transparent control and monitoring interface for any remote subsea equipment to a shoreside control station or a host platform. Alternative control links can be provided to operate over any distance. These may be RF links, Satellite or Fibre Optic. All systems are designed to provide the highest reliability and availability (99.97%) using high level specification, duplication and path diversity.
Our autonomous system design philosophy is based on aerospace techniques offering proven performance throughout. Maintenance visits are limited to 3 monthly greatly reducing operational costs. Typically around 260 tonnes of chemicals for flowline or well injection can be stored onboard with larger quantities stored at the seabed if required.
Existing systems have operated successfully for over 15 years in various locations (NW Australia and the Republic of South Africa) operating remote subsea step-outs of 50 kms and 88 kms.
The first field control buoy was installed in 1996 in the East Spar Field offshore NW Australia operating 4 subsea wells providing full control and injecting both MEG and Methanol into the wells and associated pipeline. The buoy communications used UHF line-of-sight via a retransmission link on Barrow Island together with Satellite back-up.
A second and larger fully autonomous field control buoy was designed and engineered by Ocean for the Mossgas E-M Field, 88kms from Mossel Bay offshore in the Republic of South Africa. This buoy controlled 10 subsea wells and 3 subsea area manifolds transmitting produced gas 50 kms to a host platform.
Full Autonomous Oil Production and Export
Recovery of Produced Gas by GTL Technology
Sea Producer is an Autonomous Production Buoy with Associated Storage that can process up to 30,000 bbls/d of oil (or higher) with associated gas and export the produced oil by shuttle tanker at significantly lower Capex and Opex costs from otherwise uneconomic remote fields or step-outs. It is a game-changer in the profitable development of otherwise uneconomic stranded fields. Sea Producer is:
The concept has been developed using Ocean’s existing successful and well-proven Field Control and Power Buoy (Sea Commander) technology as the platform. This “mini–TLP” design offers a more stable facility than other deepwater solutions and is the basis of the system’s reliability, simplicity and low cost. Its design is covered by various patents and registered designs and is supported by considerable technical “know-how” developed both during the design of the Sea Commander buoy systems and during development work of around $1.5 million. This work has encompassed every technical area of detailed design and has included model testing, operations philosophy, actual operation and maintenance and through-life costs.
The need for Sea Producer technology has clearly arisen as there is a gap in the market for a production system suitable for lower production rates and shorter field life projects. Current systems such as FPSO's are economic at higher rates of production or in certain special circumstances. Subsea tie-backs may also offer solutions where an existing facility is close at hand and where excessive tariffs for its use are not a problem. Furthermore as production rates decline through the life of a field there may be a requirement to remove expensive conventional production facilities with high Opex costs and close in the field early thus reducing overall recovery and payback. Existing production solutions are, however, often uneconomic or inflexible and, therefore, a new and truly economic solution is required to develop either single wells or small well groups - Sea Producer is the solution which can be used for:
Ocean has undertaken a considerable amount of engineering work to develop the autonomous production buoy concept and all of the engineering issues involved have been addressed to an advanced degree. All main technical challenges have been identified and solutions developed.
Our various technical studies have evaluated and covered a wide range of oil types ranging from heavy through medium oils to light condensate (10 to 45 + API gravity). We have examined in detail production rates to 20,000 bbls/day and implemented sensitivity studies at 500 bbls/day and 30,000 bbls/day. We have looked at base case storage configurations of 200,000 to 300,000 barrels.
Ocean's studies have explored water depths ranging from 70 metres to 1500 metres and beyond with comprehensive model testing having been successfully undertaken at HR Wallingford, Qinetic (Portsmouth), Melbourne University, etc. for depths of around 100 to 150 metres. Computer-based hydrodynamic analysis has been extensively implemented for water depths ranging from 90 metres to 2200 metres.
Produced gas of up to 5 million scfd can be usefully used for on-board power generation and for heating the stored oil (i.e. configured for oil processing only). For produced gas beyond this limit work is well in hand to ensure useful and economic processing of the associated gas to an exportable product using packaged GTL (Gas to Liquids) technology.
Finally DNV-GL has carried out a technology review and we have held detailed discussions with both the UK HSE and the Norwegian Petroleum Directorate all of whom see no technical barriers to the implementation of the Sea Producer concept.
The installed price of a Sea Producer system configured for unmanned operation to process, say, 20,000 bbls/d installed in 150 metres water depth including the buoy, subsea storage tank, risers, in-system flowlines, tethers, and tanker export system (but excluding subsea, in-field flowlines, subsea equipment, etc.) would be approximately £90 million.
Specifically the cost of Sea Producer is between 25% and 40% of the comparable through-life cost of the nearest current competing technology.
Please Contact Us to find out more about this unique technology.
We've been there, We've done It!
Remote Power Generation using produced fluid or diesel (up to 100 MW) or Remote Power Distribution (up to 100 MW)
The Sea Commander concept has been applied to the remote supply of large scale power to operate subsea oil and gas production facilities. The supply of power can be achieved by local generation using imported fuel or produced fluid (gas) and by imported AC Power. The two options are described below:
The Sea Commander Power Buoy system provides power to, and allows control of, subsea wells and/or associated subsea processing equipment from an autonomous, unmanned facility located close to the subsea well location. As such, the Power Buoy System:
The system was entirely autonomous requiring manned maintenance visits at 3 month intervals. All major equipment can be remotely monitored both by host platform and specialist maintenance personnel onshore. This system operates on imported diesel but dual fuel or produced gas/fluids are suitable alternatives.
Ocean developed and designed the CNR Power Buoy for the provision of up to 5 MW of real power to 8 operating (duplicated) Schlumberger downhole pumps located in a remote outstep and designed to pump produced fluid back to an existing production platform. In this case power was generated by 4 of 6 1000HP diesel generators located on the buoy system. Each generator was configured for long unattended operation. The power was controlled and conditioned by 8 of 9 Variable Speed Drives (VSD's) from where it was transmitted via dual umbilicals to the seabed wells at two subsea well centres each 2 kms from the buoy system. The fully autonomous Power Buoy also provided a transparent control interface from the remote outstep to a host platform located 30 kms away. Communication with the host platform was by duplicated UHF. Additional operational data could be transmitted by satellite link Schlumberger’s onshore management facility at Inverurie. The system was designed for high real time availability (of the order of 99.96% availability) using duplication, triplication, path diversity and upgraded components. The outstep was located in 150 metres of water in the UK North Sea 15 kms from the host platform.
The Sea Commander Power Buoy met the requirements of a full UK Safety Case in addition to normal verification procedures (IVB).
Remote Power Conditioning and Distribution (up to 100 MW) of Imported AC Power
The Sea Commander Power Distribution Buoy system is designed to provide a high-stability, secure and maintenance friendly environment for the location of equipment for power transformation and distribution to and for the control of buoy-mounted VSD’s (and associated equipment) and subsea located production and fluid transmission equipment (and associated systems) in or adjacent to remote subsea satellite wells. The high stability of the buoy system ensures that there is little differential movement between the buoy and seabed equipment thus providing high integrity for the power and control umbilicals which enter the buoy well below mean sea level and away from high wave energies.
The current work defined a Power Distribution Buoy to condition and distribute high imported AC Power to subsea compression and processing facilities (30MW) for very remote (350 kms) step-outs in water depths of 1500 metres. Ocean also studied and specified an AC subsea cable system with minimised power losses throughout the transmission.
Sea Commander can be used to support injection of Chemicals, Steam or Gas for Enhanced Oil Recovery (this application is known as Sea Sequestor) using imported electricity or fuel or associated gas for power generation for pumping, compression or steam manufacture.
Sea Commander can also be used for CO2 EOR. Please see Sea Sequestor.
Remote Autonomous Surveillance and/or Data Acquisition
Our Autonomous Buoy systems have been used for the acquisition of data for wind farms, civil and military vessel (surface and subsurface), surveillance, pollution control (spilt oil detection) and seismic monitoring. These activities are described under Offshore Surveillance
Remote Injection of both Treated and Raw Water
Ocean has carried out studies into remote water injection of both treated and untreated seawater for Shell and Amerada Hess. We own joint patents with J Ray McDermott for Raw Water injection from our Sea Commander system.
Autonomous Flare Buoy for FPSO's, Floating Production facilities, MFP Platforms
Sea Flare is a low cost, high throughput taut moored flare buoy capable of providing safe emergency flaring at a fraction of the cost of alternative high throughput flaring systems and giving safe radiation spacing to offshore production facilities, both floating and fixed where separate flare structures are not cost-effective.
A Sea Flare buoy system has been operating successfully on Exxon-Mobil's Zafiro field since 1998 where it was originally installed as an emergency measure following the loss of the original flare buoy during installation. The buoy supports twin 20" Coflexip mid-water suspended hoses from the Zafiro Producer. The buoy is stationed approximately 200 meters northwest of the floating production vessel and will flare in excess of 35 MMcf/d of gas.
Ocean can design, construct and install autonomous flare buoys for any facility for high emergency flaring rates at a fraction of fixed structure costs or even the cost of alternative floating solutions.
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