This paper summarises original development work implemented by Ocean Resourceinto a new type of Unmanned Production Buoy facility, the Sea Producer. Thiswork, which is both comprehensive and wide-ranging, covers the use ofautonomous buoy technology to develop various offshore oil and gas productionscenarios which would otherwise be uneconomic or indeed impossible. Recentlythis technology has received considerable interest as it represents, for somesmaller developments, possibly the only sensible and economic way forward. Thedesign concept is flexible and has applications well beyond simple production.Ocean is carrying out on-going development work into the use of the concept forcarbon sequestration allied to enhanced oil recovery. This novel developmentwill provide an initiating technology for offshore carbon sequestration againat hitherto highly economic costs. The detail of this is, however, beyond thescope of this paper.
Ocean Resource has developed and pioneered the concept of remote offshore oilor gas production from an unmanned production buoy over a period of 20 yearsand is the only company with specific experience and expertise in this complexarea. Ocean has designed, built, operated and maintained its own high stabilitybuoy systems and has completed a number of buoy designs for working buoysystems in use with Apache, Mossgas Pty, Exxon-Mobil and others for oil relatedoperations. More recently Ocean Resource has been responsible for the design ofa 5MW Power Buoy for CNR International UK Ltd (Canadian Natural Resources).Unfortunately Monitor Oil PLC, the principle constructor, went into liquidationprior to completion of the project but it is envisaged that this unit, which is95% complete will shortly be redeployed on another field. The Power Buoylocated at Dundee is subject to an option agreement for this purpose.
Ocean Resource's low cost autonomous buoy systems represent a game-changingtechnology that will enable the economic development of hitherto unexploitableor stranded oil and gas reserves. The technology is generally branded as SeaCommander where it relates to field control buoys (a developed product) and SeaProducer where it relates to production.
Sea Producer enables a step-change in offshore development expenditure loweringcapital costs at the start of project together with greatly reduced operationalcosts leading to low "through-life" costs for standalone, step-out developmentsor early production scenarios. Furthermore the relatively minimal nature of theoffshore facilities comprising the buoy and storage system leads to rapiddeployment and hence faster income and profit return to any offshoreproject.
The unique autonomous buoy technology has been developed by Ocean Resource overa period of 20 years and is an evolution of existing systems first deploed inthe 1980's. It is therefore both mature and proven. It can be used for sub-seaoil and gas field control, remote pigging, multi-phase pumping, chemicalinjection, subsea production support and remote flaring.
Today the development of subsea fields or satellites and the remoteness of thelocation not only require subsea processing but have also has implications forthe provision of power. The norm for offshore power generation is the use offossil fuel. However, the uncertainty surrounding a global climate policy at atime when the projection is for an exponential increase in offshore powerdemand is a cause for pause to look at renewable power solutions. Types ofrenewable power solutions that have application to the offshore oil and gasindustry include: solar, wind, and ocean energy (various).
This paper provides a rank/value for offshore power generated with bothrenewable- and conventional- energy sources relative to four (4) projectscenarios: Status Quo, Supply-to-the-Rescue, The Green Agenda, and DoubleJeopardy. The work to select a power solution began by identifying a key focusquestion about the future that the scenarios would address: How will the demandfor offshore (subsea) power and the potential externalities that may resultshape the power generation options over the next decade? The paper also pointsto resources that can shed light on the latest technological advances andfuture trends for renewable energy sources. The hope of the author is that thepaper will prove to be a useful reference for R&D specialists and projectengineers who are often asked to respond to the question: Renewables - Ready orNot?
The Spar platform has developed into a well functioning solution for Gulf ofMexico environment. Considering use of this solution in the North Atlantic, themetocean conditions differ by long period swell and fatigue induced by normaloperational seas.
In order to meet these challenges, it is desirable to consider a classic Sparthat is more fatigue redundant than a truss, but the swell requires highnatural periods, to avoid parametric heave-pitch resonance.
A new version of the Spar in response to these requirements is the Belly Spar.It can be considered as a classic Spar with a Belly; starting below the wavesurface and extending down to the hard tank depth. A concrete Spar concept withreduced waterline diameter has also been developed by Aker Solutions for arcticapplication. This concept had the dual benefit of increasing the natural periodin heave as well as reducing the ice load from sea ice
The concept has been developed for a field in the Norwegian Sea, in water depthof 1,200m (4,000ft). The hydrodynamic analyses show excellent performance,however contain assumptions on damping. The design has been by model testing ofthe design in wave and current combination representing 10,000yr events, asshown by results and correlations in the paper.
The design opens up new areas for the Spar platform, with good motions that canaccommodate steel catenary and top tensioned risers. As for previous Sparconcepts, the application is in deepwater and ultradeepwater.
The plans for many of the upcoming deepwater projects involve the use of highpower Electrical Submersible Pump (ESP) Systems for Artificial Lift. However,the perception in the industry is that the average run-life currentlyachievable with such high power ESP Systems is much shorter than what would bedictated by robust project economics, given that intervention costs in theseapplications can be very high, in the US$50MM - 75MM range. Therefore, theconsensus among operators is that there is a need to try and improve thereliability of these systems.
In response to this industry need, DeepStar® recently commissioned a gap studytowards identifying the barriers that may be preventing ESP Systems fromachieving the desired reliability as well as the additional R&D effort thatmay be required for the industry to close the existing gap. DeeepStar® providesa forum for deepwater technology development, while leveraging the financialand technical resources of the industry (http://www.deepstar.org/).
This paper presents a summary of the results of this study, including: a) theMean Time To Failure (MTTF) that people believe is currently achievable (i.e.with current technology); b) the biggest differences about these applications,which introduce additional uncertainty to the ability of the system to performreliably; c) the main sources of uncertainty regarding each of the major ESPSystem component's reliability; and d) the tentative plan that was outlined aspart of the project, to address the gaps that were identified.
The Gap Analysis was based on phone interviews conducted with recognizedindustry experts, on discussions that took place with members of a TechnicalCommittee (TC) that was put in place for the project, and on a broader industrysurvey conducted through the internet. The proposed go-forward plan consists oftwo follow-up projects: one focused on improved system design and operationalpractices, including system monitoring (or surveillance) and control; and onefocused on validating the design of key components of concern, for thespecifics of these applications, through laboratory testing. The proposednear-future R&D effort has the support of major operators, but still needsto be fine-tuned, with input from the industry, before the actual work canproceed with buy-in and financial support from all of the partiesinvolved.
New oil and gas frontiers are presently looking at projects offshore of theGulf of Mexico and South Atlantic, including West African and Brazilian watersand soon after Asia Pacific. New technologies are required to performinstallation in a cost efficient and safe method; they must encompass the stateof art equipment in order to provide effective solutions. The new ships FDS2and CastorONE are Saipem's replies to the forthcoming challenges indeep/ultra-deep water field development and pipe lying. The new vessels willoperate by using new welding, NDT and field joint coating technologies,including innovative installation equipment able to generate added value forthe implemented solutions. Field development projects include complex risersystems and the new fleet is designed to offer reliable solutions for thefuture configurations, which are designed to route the oil and gas fluids tothe floating treatment units. Saipem FDS2 is described by indicating hercapabilities and her equipment, including those required for project in shallowwater and those specifically designed for deep waters installation.Furthermore, sea keeping and naval features are offered in order to demonstrateher versatility and ability to solve main installation challenges relevant tothe deep water fields. Trunk line projects will be addressed to transportationof large gas volumes over long distances across harsh environments and Saipemvessel CastorONE is presented by showing off her capabilities for the ultradeep water installation. Information on the new state of art rigid stinger isprovided together with some conceptual solutions designed to increase theefficiency of the working stations and of the method to transfer the pipes withspecific equipment. The paper concentrates on the installation requirements forthe in-field production gathering systems and on the oil and gas exportpipelines.
Field development: the leading market trends
Since 1998, numerous deep water field development projects, mainly in the SouthAtlantic region both in West Africa and in Brazil were carried outsuccessfully. The vision for the future leads towards two major trends: evendeeper waters and new surprising geographical regions. Moving in bothdirections, thanks to its top class technologies and assets, Saipem aim to leadthe path towards the even tougher future challenges.
The scope of the work of deep water projects, within EPCI type contracts, hasnormally included all major and minor technical aspect, supplies andinstallation/operations from A to Z, with contract values typically in therange of half to one billion USD. Key of this market segment - which nowrepresents a significant portion of turnover and backlog - has been theintegrated development of original technical solutions and dedicatedfit-for-purpose installation vessels.
Leveraging on its notable competence, track record and offshore constructionfleet, the two main lines of evolution for the offshore field developmentmarket were, are and will be tackled, namely ultra-deep waters and new frontierregions as follows:
• On one hand, the ultra-deep water developments, emerging in the traditionaloil provinces in the Gulf of Mexico and South Atlantic, will require theIndustry to make available new technologies and equipment to support the safeand effective implementation of the relevant production schemes;
• Simultaneously, the development of subsea oil and gas fields is taking placein new world regions bringing quite new challenges from both the technical andexecution standpoints.
Exploitation of oil and gas reservoirs in water depths in excess of 2,000m (?6600') is progressively emerging as the new market. Gulf of Mexico, offshoreBrazil and West of Africa are nowadays showing the greatest concentration offield development projects. In addition, subsea developments in new areas suchas East India, Indonesia, Offshore China and Western Australia are appearing inthe offshore oil and gas theatre both for relatively moderate and for deeperwater depths.
Perdido Regional Development in the Western Gulf of Mexico and the Walker Ridgearea in the Central Gulf of Mexico will be significant and challenging offshoreprojects.
This paper presents an overview of wet gas multiphase metering and a new meterdesign to meet future offshore challenges. The design introduces new microwaveelectronics, transmission as well as resonance measurements, a salinitymeasurement system, reduced PVT dependence and a new HP/HT design.
Building on the success of wet gas metering in accuracy and reliability, thenew meter increases operators' ability to detect the onset of formation waterproduction and accurately measure flow rates where an increasing amount ofliquid and water is present in the flow (due to gas wells produced over a widerrange of process conditions).
The new meter design will have an increased importance for subsea tiebacksapplications. While today's wet gas meters are well suited for subsea tiebacks,current subsea developments require longer horizontal production pipelines,where accurate and sensitive measurement of water is crucial to ensure flowassurance and maintain maximum production capacity of the pipeline.
Furthermore, the restrictive and remote nature of subsea fields means that thecosts for subsea interventions and periodic fluid sampling (PVT) are high. Thenew meter is more robust to changes in PVT (fluid composition) and reduces theneed for frequent fluid sampling.
The paper will describe the development and technology choices of the newinstrument and how it will meet future subsea field demands.
It will explain how the new microwave electronics provides more stable andaccurate measurements; how transmission and resonance measurements extend theoperating range to 80-100% GVF and 0-100% WLR; how two complementarytechnologies - a salinity probe for liquid film measurements at low GVF andFormation Water Detection Function software for droplets measurements at highGVF, provide the first complete salinity measurement system in wet gasapplications.
The paper will also show how multivariate analysis and new measurements enablethe meter to compensate automatically for changes in produced fluidcomposition.
The paper will be highly significant to oil and gas operators looking toincrease flow assurance and oil & gas production from wet gas fields andmeet the growing offshore challenges of varying process conditions,intervention costs, and subsea tie-backs.
Installation of offshore platforms in carbonate soils is challenging, asevidenced by numerous incidents and accidents. The installation process ofmobile jack-up drilling rigs is no exception. The prevalence of these soils insome oil and gas producing regions, such as offshore Australia, necessitatesthorough understanding of the foundation behaviour as well as predictionmethods capable of capturing the salient features. This contribution thereforedevelops a method to predict footing penetration in uncemented carbonate sand.The method directly correlates the cone penetrometer tip resistance with thefooting load-penetration, i.e. without the requirement of selection of afriction angle. The development is based on centrifuge model experiments aswell as large deformation finite element analyses incorporating an advancedconstitutive model for the soil. The direct use of in situ site investigationdata increases the confidence in load-penetration predictions for rig moves inthese challenging soil conditions, while at the same time reducing the timerequired to obtain a prediction.