bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ageing and Fatigue Life of Structural TLP Flexelements
Authors: Gunderson R.H. , Stevenson Andrew 
Published: October 2008

Abstract
This paper presents a methodology for estimating the fatigue life of elastomerlsteel flexelements that includes the effects of both mechanical fatigue loads and ageing of the elastomer. Previous methods calculated the rate of fatigue crack growth in the elastomer layers of flexelements using fracture mechanic analysis and a material fatigue model obtained from tests on new elastomer materials which ignored ageing. This workshows how elastomer ageing can be taken into account and the impact this can have on the calculated fatigue life.
This methodology has been applied to the Design verification of the structural flexelements for the RamPowell TLP tendons to be installed in the Gulf of Mexico in 1997. The tendon flexelements carry the full tendon loads and provide near moment-free joints at the top and bottom of each tendon. The analysis can also be used for riser system flexelements and other elastomer steel layered structural components.
The physical properties of elastomers change with age. The fatigue life of the Ram/Powell flexelement was Calculated to be 5160 years based on the properties of new Elastomer. When the properties of the ageing elastomer were taken into account, the calculated fatigue life ranges from 160 years to 400 years depending on the conservatism of the assumptions used. The effect of ageing is obviously significant. The analysis uses data generated from elastomer samples exposed to accelerated ageing conditions. A special purpose fracture mechanics program calculates the crack growth in each layer for each load in the yearly fatigue spectrum. The material properties are updated and total crack length is computed on a year-by-year basis until the failure criteria is reached.
The present approach may remove some of the uncertainty associated with structural elastomer design, result in more realistic estimates of elastomer fatigue life, and may lead to the use of safety factors commonly associated with the design of more familiar structures.

Introduction
Flexelements are primary load bearing components of the tether system of tension leg and so it is of the Ram Powell TLP it was desired that a large safety factor be demonstrated. Previous work had developed and verified a fatigue analysis method for flexelements. This, however, ignored the effect of ageing of the elastomer with time, whereby the elastic shear modulus may increase and the fatigue resistance may decrease. Previous work had been based entirely on data from new elastomer material and did not include an ageing model in the fatigue calculations.
Limit State Design of Subsea Flowlines for Pressure Containment
Authors: Mahendran Indu K. , Al-Sharif A.M. , Young Charles D. , Langner Carl  C. 
Published: October 2008

Abstract
The current API and ASME design codes on wall thickness selection are too restrictive for the application of high pressure subsea flowlines. At present the codes require flowlines to be designed to wellhead shut-in pressure using Barlow design formula, which is based on first yield, and working stress safety factors established decades ago. Recent advances made in pipe manufacturing, design engineering, and the considerable plasticity of thick walled steel pipe render the current design overly conservative, resulting in severe cost penalties for long distance subsea tiebacks.
The current work describes the application of Burst Limit State Design principles to the design of subsea tiebacks. The paper discusses the limitations of the classical approach and quantifies the uncertainties, risks, and economics of limit state design, based on results obtained from burst pressure test data obtained from various industry sources. It is expected that this work will lead to a review of the existing codes by the regulatory bodies and the recommendation to change current in design practices.
The work will enable deepwater subsea tiebacks to be designed in accordance with limit state principles and safety factors reflecting the current state-of-the-art technology of pipe materials, manufacture, welding, quality control and pipeline design. This will lead to the optimum design of subsea flowlines.
This work is mainly directed towards the large D/T ratios required for high pressure subsea flowlines, and is different from the low D/T ratio work carried out by SUPERB and IS0 working committees in Europe. However, it is intended that this work will complement the work carried out elsewhere, leading to a consistent application of burst pressure design to pipelines and flowlines.

Introduction
DeepStar 3300 Committee commissioned a study to evaluate the feasibility of using the Burst Limit State criteria to design subsea flowlines. The work consisted of:Collection of data from published sources and DeepStar members.Identification of Limit State Design models for Burst Assessment of code compliancePreparation of submissions to API and ASME for code changes
The work presented here is limited to the Phase 1 of the study, and includes a description of the data collected, and the preliminary Limit State Design philosophy under development. Comparative cost data for current design practices, and Limit State Design also given to establish the potential cost savings of using Limit State Design.
Recognition of the uncertainties associated with engineering systems has led to the wide application of the concept of reliability as a basis for structural design. This is evidenced by the move in Europe and North America to develop limit states codes for pipeline design.
Underbalance Perforation in Long Horizontal Wells in the Andrew Field
Authors: Kusaka K. , Patel D. , Gomersall S. , Mason J. , Dought P. 
Published: October 2008

Abstract
The comparison of today's slickline capabilities with its early usage for routine remedial workovers and maintenance best illustrates the significant advances that have occurred within slickline technology. Today, for example, slickline can be used to I) set and retrieve slickline-retrievable safety valves or plugs, 2) open and close downhole circulating devices, 3)retrieve accurate depthhime data for correlating with memory production surveys for well diagnostics (problem identification) reservoir description, or flow analysis, 4) provide accurate correlation of tubing casing collars, and 5) pull and run multiple flow controls set packers and other downhole equipment without explosives; setting monobore tools; and other perform other well interventions that are dependent upon measurement accuracy. Less than a decade ago, slickline was only considered for mechanical well workovers.
This paper will discuss the newly developed technology that allows slickline to economically provide alternatives to services traditionally reserved for other, more costly options. Case histories will be used to illustrate the enlarged scope of services and how the equipment combines to provide the innovative low cost service options that the industry has been seeking.

Introduction
Economic initiatives are usually the drivers of new technologies, and thus, reacting to the significant decline in the oilfield climate during the last decade, no era has been as momentous in providing stimuli for operational change. Unfortunately, operators who are seeking new methods usually look to new technologies as the potential problem solvers, and in so doing, overlook enhancements to the older, proven technologies that could provide the cost efficient alternatives they want.
This has been the case with slickline. Until the resurgence of investigation into new strategies to meet the oilfield cost constraints of the last decade, slickline service was only considered for routine mechanical workovers. Who would have considered using slickline to set a packer in the early 90's.
The capabilities that have changed the profile of slickline service from one of routine mechanical well work overs to a multi-faceted service technology are derived from the new slickline tools that can be used independently or combined to further enhance the scope of services. The equipment includes an electronic triggering device (ETD) that enables safe detonation of explosive devices, a battery-operated, electro-mechanical tool that sets wellbore devices on slickline and braided line without explosives, an electronic measurement system that automatically corrects measurement inaccuracies resulting from line stretch and environmental stress factors, a slickline collar locator (SLCL) that accurately verifies collar locations in a tubing string, and data job loggers or acquisition software systems that connect to the electronic measurement system to graphically record dynamic wireline information.
Development & Application of a Through Tubing Multi-Lateral Re-Entry System.
Authors: Brooks Robert T. , Stratton J. Jay 
Published: October 2008

Abstract
The drilling of multi-lateral wells is an established process, but the selective entry, and reentry of single, or multiple, lateral wellbores is an engineering problem that is still being addressed. The economic rewards from multi-lateral wells have not been reliably understood due to the unpredictable nature of overall costs versus performance. Poor capabilities for reservoir surveillance contribute to the difficulties in evaluating production performance and drainage efficiency from individual zones. Performance evaluation can be M e r complicated by effects of cross flow from adjacent heterogeneous zones.
This paper presents a completion system that allows recovery of considerable reserves from the 'A' and 'B' zones of the Shuaiba reservoir in the Idd El Shargi North Dome Field, while providing cost effective reservoir surveillance of zones drilled with horizontal multi-lateral well technology.

Introduction
The Idd El Shargi North Dome Field (ISND) is situated in the Arabian Gulf, 90 kilometers east of Doha, Qatar (Fig 1). The discovery well for ISND, IS-2, was drilled in 1960. Production began in 1964.
Initial production from the field was from Jurassic Araej and Uwainat Formations. Production was later achieved from the Jurassic Arab Formation and Cretaceous Shuaiba Formation. The majority of production is from the Arab 'C', Arab 'D', and Shuaiba Formations. About 2.0 billion bbls of the ISND Fields 4.2 billion bbls OOIP are in the Shuaiba Formation. Still, the reservoir is relatively undeveloped. The Shuaiba is a carbonate formation with reservoir top at about 4500 feet subsea and capped by the Nahr Umr Shale. A 600 ft oil column is divided into 4 geologic zones, the Shuaiba 'A', 'B', 'C', and 'D'. The Shuaiba 'A' and 'B' intervals, with average porosity of 24% and permeability of 5 md, hold 82 percent of the Shuaiba OOIP. The intervals are separated by a tight layer in many areas of the field. With an existing infrastructure already in place, the low permeability Shuaiba 'A' and 'B' intervals are prime candidates for horizontal multi-lateral development that can optimize use of remaining well slots and production facilities.
Well IS-76 was selected as the first horizontal multilateral completion candidate. The main borehole was drilled to a horizontal orientation in the Shuaiba 'B' interval, and 9- 518" casing cemented in place. The casing string included an oriented predrilled casing exit window. This was run in the casing string at the depth where the lateral borehole was to be drilled into the Shuaiba 'A' interval. The orientation of the pradrilled casing exit window was to the high side of the casing (to prevent any debris entering the lateral bore at a later date). After cementing the casing in place, and subsequent clean out work, a drilling whipstock was run in the well.
Multiphase Flow Meters and Application Trends
Authors: Hatton Gregory J. 
Published: October 2008

Abstract
Multiphase flow meters are being utilized to provide well test data in a growing number of oil production applications. These include subsea applications that eliminate the need for costly well test lines, topside applications that minimize platform space and load requirements for well testing, and applications in remote or unmanned locations. This paper reviews key technologies used in the commercial meters being deployed in the field in significant numbers, and trends in multiphase flow meter applications.

Introduction
Multiphase meters are systems that meter multiphase flow streams in situ i.e., they meter the individual component flow rates without first separating the components. As well test systems, multiphase meters measure the gas, oil, and water flow rates of a well stream without large conventional three-phase separators.
Multiphase flow meters differ from conventional well test systems in several ways. Generally, multiphase flow meters (1) measure well production rates quicker and with less human intervention, (2) are smaller and less massive, (3) provide additional valuable data, and (4) are deployed subsea.
Traditionally, operators have monitored individual-well flow rates to maximize field and reservoir performance with conventional three-phase separator, well test systems. In these surface well test systems, ideally, a three-phase separator provides pure oil, pure water, and pure gas streams to single phase meters. In subsea applications, (in addition to a production line) a test line is laid from a subsea manifold to a conventional well test system on a platform to allow testing of individual wells. As the platform-to-subsea-manifold offset increases, the difficulties associated with acquiring accurate well tests (for a range of flow rates) increase, and for large offsets. a conventional test-line system becomes ineffective. The capital costs and the operating costs (including man power) of traditional systems have lead to the development of multiphase flow meters. These meters are intended to reduce costs and manpower requirements, and to provide timely well testing at remote locations.
The effective application of multiphase flow meters requires an understanding of their working principles and how these affect:Qualification of a meter for a particular application. Installation considerations.Calibration during the field lifetime.Accuracy of the measurements under various conditions.Stability and repeatability of the measurements.Measurement robustness. (That is, how resistant is the meter to being fooled and reporting erroneous rates?)Meter state-of-health evaluation.
In order to obtain desired metering performance, each application should be carefully engineered with regard to meter selection, installation, calibration, and data handling and interpretation.
Multiphase flow meter manufacturers provide a range of viable well test systems for subsea, topside offshore, and onshore applications. These meters use relatively high levels of electronics and are designed for unmanned operations.
Alwyn Area: A Case History in Improved Business Performance
Authors: Dundas I. , Grosjean Y. , Hervochon J. 
Published: October 2008

Abstract
The Alwyn North field, situated in the UK sector of the Northern North Sea, came on stream in late 1987. Development used classic North Sea technology. Plateau production was originally forecast to last no more than four years for oil, and seven years for gas.
Over the past three years Alwyn North has been developed into an integrated area operation with the start-up of the adjacent minimum-facilities Dunbar field and the sub-sea development of the Ellon field. The Dunbar field has made full use of new technology, including Tender Assisted Drilling, a lightweight jacket and multiphase export. Substitution terms incorporated within the gas sales contract allowed movement into new emerging UK gas markets.
Increased reserves have been identified by the application of 3D-seismic and the further appraisal of new (and old) reservoir compartments. Increased productivity has been achieved through debottlenecking of the process plant and by drilling long reach horizontal wells. Increased cost effectiveness has been delivered by a "continuous improvement" campaign resulting in OpEx reductions and increases in oil and gas sales.
A further phase of developments is now in preparation. On Alwyn North an infill drilling campaign is scheduled to follow the interpretation of the newly acquired second 3D survey, and a miscible gas injection scheme is currently being studied. On Dunbar the installation of multiphase pumps will sustain export potential and further sub-sea developments will be phased in. An autonomous power supply and acoustic communication scheme is under review to improve economics of long distance tie-backs.

Initial Development of Alwyn North
The Alwyn North field, developed jointly by Total Oil Marine plc (33.3% - operator) and Elf Exploration UK PLC (66.7%) was originally discovered in 1975. Development consent was given in 1982 on the basis of initial recoverable reserves of 385 Mboe (200 Mbbls of oil and 26.6 Gm' of gas) with a production plateau of four years for oil, seven years for gas, followed by a progressive decline through to 1998. A series of discoveries had been made in an area to the south of Alwyn North, but they were considered uneconomic to develop at that time.
The field is situated in the northern sector of the North Sea, 140 kms to the east of the Shetland Islands and 465 kms north-east of Aberdeen, in close proximity to the Brent and Ninian fields (Fig 1).
There are two main reservoirs. The Brent oil reservoir at 3,100 metres is hghly compartmentalised into panels, each supported by water injection. A total of ten oil wells and seven water injectors were drilled. The Statfjord gas reservoir, slightly deeper at 3,400 metres, was developed by twelve wells using natural depletion (Fig 2).
Contribution Of Flexible Pipes And Riser Systems To The Development Of Subsea Hydrocarbon Resources
Authors: Narzul P. , Dumay J.M. , Rigaud J. 
Published: October 2008

Abstract
The paper reviews the parallel developments of the flexible pipe technology and of the subsea industry. It analyses the key characteristics which have made this development possible and which are, basically, flexibility, modularity and versatility. This has allowed the flexible pipe not only to stick to the market, but even to make it possible, as it is an element without which floating production systems would hardly exist. As a result, flexible pipes are now natural components of most subsea developments.

Introduction
The contribution of flexible pipes to subsea developments was recognized in 1995 in this very forum, under the form of an award for "distinguished contribution to the development of subsea oil and gas technology", which, in itself, justifies the title of this paper. However, when the flexible pipe was first conceived, this was not a foregone conclusion.
The history of technology is full of inventions which turned out to be successful in ways their inventor had not always foreseen. Flexible pipe technology is a good example of this. The award came more than 25 years after the concept was developed by the French Petroleum Institute (IFP), and it is ironic to reflect that, initially, the product was not aimed at the subsea industry which, anyway, was still in its infancy at the beginning of the seventies but at drilling technology. This pplication was not a success, so that in 1972 the flexible pipe was really a product without a market.
The purpose of this paper is, beyond briefly recalling the history of the technology, to explain why flexible pipes answered the challenges of subsea developments and how the adequation of the product to the market was maintained as the range of applications was extended. The most interesting question for the future is whether this fit between a product and a market will persist as the subsea industry evolves. This will be discussed in the last section.

Historical milestones
The first flexible pipes where built in the early seventies to replace the steel stems traditionally used for drilling. The ambitious objective was to eliminate the time-consuming manipulation of drilling stems which is required whenever the drilling head has to be changed. The idea was interesting, and the first trials were relatively successful, but the torsional properties of flexible pipe were too low and the pipes were quickly and easily damaged. There was no hope that this technique could replace the current, field-proven methods and the idea was abandoned. In the meantime, Elf needed a short flowline in West Africa, on the Emeraude field, in order to transfer crude oil between two platforms. This is when the application of flexible pipes to the offshore oil industry was first considered and implemented, in 1973. However, this market remained somehow anecdotal and the number of applications limited.
Computing and Visualization Point the Way Ahead for Reservoir Characterization
Authors: Neidel Norman S. 
Published: October 2008

Abstract
Progress in modem digital computing and related display technology have propelled seismic technology and the use of geological information into an era where imagination has no bounds. Displays we now can view almost routinely are particularly impressive. At the same time such "enabling" processes point out the weaknesses in the state-of-the-art as well as noting the strengths where we use seismic and geologc data to find and define hydrocarbon reservoirs.
Where single type data sets are treated individually, well logs, seismic data, engineering measurements, etc., the &splays we can create and the insights which we can develop are quite remarkable. The new tools which we employ, diprates, coherence values and such are just the fore-front of the avalanche of progress which will inevitably follow.
Where we fall short is when we must integrate or synthesize differing data types. The principal failing here is in establishing analytic formalisms connecting the various types of data. Without these mechanisms reliance is placed on geostatistics, but at a stage which in many instances is premature. It is likely that the inconsistent and limited success of such methods rests with this circumstance and underlying deficiency.
The likely avenues for future developments should follow from these two themes. We should see further progress of course where there has already been success - more and better analyses will delve still further into the significance of the data we have. At the same time, the urgent need to crossrelate data using underlying physics-based models will motivate new approaches. These should improve both effectiveness and the scope of applications where data synthesis is involved. Under such circumstances geostatisticsshould take on a more appropriate and reliable role.
AS these developments further mature, we shall move from marveling at the form of the displays we may conceive. to an appreciation of their substance. The examples and studies 4; sw now indicate that the projections offered here are not overstated, but are in fact quite reasonable.

Introduction
Recent advances in seismic technology while spectacular in was presented accomplishment have been tied only rather loosely or indirectly to the underlying geology. As one example. 3D surveys have primarily progressed imaging of structures, but have had more limited success with stratigraphic objectives. Such applications are however, starting to emerge as for example use of the Amoco Coherence methods in delineating channels on time slice presentations. At the same time, improvements in geologic understanding and newer tools such as basin models remain poorly coupled to seismic technology. Seismic stratigraphy remains at present a qualitative method - almost an art.