bluuebunny/crossref_metadata_2025 huggingface dataset:
Load-Testing of Web Site Applications
Authors: Raghavan Vijay V.
Published: October 2011

The growth in e-commerce has been accompanied by an enormous need to host robust web sites. Electronic Commerce has changed the role of Information Technology (IT) function from its elementary business support to providing key competitive advantages. Rapid changes in several technologies, while improving the ability to develop and deliver web sites quickly, have also increased the complexity of designing and managing them. It is easy for a consumer or business partner to change to a different supplier if an in-house or outsourced E-Commerce site does not perform up to expectations. Implementing an appropriate web-application testing program is critical in an environment where barriers to switching suppliers of web sites are minimal. Developing robust web sites that perform well under varying loads can be ensured only by a rigorous testing of these web sites before launching them in a production environment.
Software Process Models are Software Too
Authors: Turk Daniel , Vaishnavi Vijay
Published: October 2011

A software process model describes a set of partially-ordered sequences of activities that are carried out in order to accomplish certain goals. While numerous process modeling approaches have been proposed over the years, it seems that none of them have yet addressed the full range of concepts described in this definition. Most focus on activities and activity ordering; few, if any, focus on representing organizational goals and process improvement. Most provide concrete implementation approaches; few, if any, describe the general model(s) upon which these implementations are built. This paper suggests a new approach for developing software process modeling systems. If “Software Processes are Software Too,” as suggested by Osterweil (1987), then so are software process models, and hence there may be processes and models that are used in regular software development that may be useful in the process modeling domain as well. The paper focuses on the domain class model as an example of one type of model that might be produced if an approach such as the Unified Process were used in the process modeling domain. Such a process, and the set of models produced by it, if used, may be helpful in moving the process modeling field forward. While identifying the conceptual needs of process modeling systems, these models leave totally open the choice of how to formalize and implement actual solutions. A domain class model for process models is developed as an example of one of these models.
Experimental Methodology of the Accumulated Plastic Strains (APS) Effect Evaluation on Steel Tube Umbilical (STU) Performance
Authors: Nascimento Filho Antonio Pereira , De Vasconcellos Daniel Luiz Bardanza , Oliveira J.D. , Godinho Carlos Alberto
Published: October 2011

Description of the Proposed Paper

This paper presents the results of a research project entitled "Experimental Methodology of the Accumulated Plastic Strain Effect Evaluation on Steel Tube Umbilical Performance", performed by Prysmian. The objective is to suggest an increasing of APS level in order to consider it on Steel Tube Umbilical design fatigue life. Experimental methodology through laboratory testings and prototypes in order to evaluate the actual influence of the high steel tube Accumulated Plastic Strains (APS) was used. Usually, APS can be accumulated during the steps of manufacturing and installation and may impose some restrictions for the steel tube umbilical performance and service life, manly when retrievals and post-installations are required. Normally in the market, it is stated that the level around 10% of APS does not down rate the steel tube performance, and the intention of this project is to increase this limit up to 30% of APS. For this purpose it was compared the pratical results from S-N curves between the welded steel tube and the theoretical calculation methodology according to international standard [1].

A more realistc figure regarding to the maximum level of APS will give to the offshore players a more precise idea of the feasibility to an umbilical project or requirement.

Methodology

For imposing APS on steel tube, the reeling and unrelling methodology was used. It consists of passing the tubes ½??x1.46 mm SAF 2507 from one reel to another and viceversa. So, the APS calculations consider the diameter of the reel and the number of reelings in order to achieve 30%. The samples were already welded in order to be more conservative. The calculations for imposed APS were based on [2].

Results, Observations, and Conclusions

From the comparison between experimental test results (30% APS welded samples) and DNV curve, it was observed that there is no significant variation on the steel tube fatigue life, when imposing such level of strain. The respective S-N curves are presented in Figure 1. Two experimental curves are presented. The green curve is the mean SN obtained from the experimental results, while the red one is the curve for a 95% confidence interval. Figure also presents the curve for steel tubes provided in the DNV-RP-C203 (in blue). It was also verified that the mechanical and fatigue properties are not affected. The final conclusion is that the level of 30% of APS can be used by the umbilical manufacturers with a certain safety factor.

The petroleum industry is still some uncertain regarding to the maximum level of APS, in face of that, this paper proposes and presents the validation tests for 30% of accumulated plastic strain on steel tube component for use in umbilicals.
Successful Qualification and Deployment of a High Pressure Drill Pipe Riser in West Africa
Authors: Camus Mathieu , Auclair Pascal , Horsburgh Barrie , Gallois Yann , Rohart Christopher , Miller Jim , Mfoulou Yannick
Published: October 2011

The Cameron/TOTAL Usan project team brought one of the first High-Pressure Drill Pipe Riser for Intervention Systems (DPRISi) to the African deepwater market in 2009.

Since July 2010, the string has been used offshore Nigeria. A total of 20 runs have been performed with this DPRIS, resulting in the safe and efficient installation of four trees. These trees have had no cleaning issues and no rust debris impacting operations.

Proper operating procedures implemented by field personnel have allowed for safe and efficient subsea DPRIS runs to date and provide confidence in future runs (38 more trees are planned).

Before DPRIS, most operators used conventional drill pipe available on rigs to install and retrieve the production adapter base and tree cap. While success varied, difficulties and risks arose using a hydraulic umbilical inside the riser, making it evident that technological improvement was needed to minimize interference between the pipe and the hydraulic lines.

The pipe delivered as part of this project, from VAM Drilling, are drill pipe risers with a propriety double shoulder connection and featuring a gas-tight metal-to-metal seal on the inner shoulder.

The standard offer for high-pressure DPR is 6-5/8" 0.5" wt and X-95 grade. VAM Drilling suggested this be changed to have a thick wall for corrosion allowance and higher grade for tensile strength, 6-5/8" 0.625" wt and G-105 grade.

The qualification program additionally covered all remaining requirements for full compliance to ISO-13628-7, which is believed to be a good certification level for such demanding and challenging operations.

The DPRIS system delivered in West Africa is a cost-efficient solution for subsea operations, workover applications and well intervention. This successful project, which provides technical and commercial value, is an example of how to implement a successful deepwater intervention business, not only in Africa but throughout the world.
Prevention of Fretting/Wear Damage in Pressure Armour Layers of Flexible Pipes Designed for High Pressure Applications
Authors: Fernando Upul Shanthilal , Dodds Neville , Leyland Jonathan , Graham Geoffrey , Sheldrake Terry H.
Published: October 2011

Pressure armour in unbonded flexible pipes is constructed using helically-wound profiled wires specifically designed to provide hoop strength; in high pressure applications, several layers are wrapped to provide the necessary hoop strength. During service, the wires in individual layers are in contact and move relative to each other due to dynamic flexing. Analysis of such interfaces is complex, as the contact between the layers is non-uniform, discrete and nonconforming. Discrete contact geometry often leads to high stress hot spots that can lead to regions of fretting/wear in the wire under certain conditions. Knowledge of the local interactions between individual layers and the ability of the pressure armour wires to withstand such local contact under applied dynamic sliding conditions is essential to guarantee the necessary integrity and durability of the pipe to withstand service pressure loading.

This paper discusses a pipe with two pressure armour layers. A finite element model has been developed to predict both the dynamic interaction between layers and the contact stick-slip behaviour between the wires under dynamic loading. The numerical results of this work, together with the fretting/wear damage behaviour of the wire material developed in a previous study, have been used to assess the fretting/wear damage of the pressure armour wires of the pipe. An evaluation method has been proposed to predict the safe loading envelope that would not lead to wear/fretting of the pressure armour wires.

The method involves the evaluation of subsurface stress distribution at the wire contacts in the pipe, which is used with material yield properties to predict the size of microscopic plastic zones. Loading cycles to crack nucleation are predicted using experimental data generated under similar loading conditions. A brief discussion is provided on the fretting damage behaviour of flexible pipes under service conditions.
A High Resolution Regional Ocean Model For Brazilian Pre-Salt Area: First Validation Results
Authors: Schoellkopf Jacques P.
Published: October 2011

The Project:

The PreSal 36 ROM JIP is a project for the development of a powerful Regional Ocean Model of 1/36 of a degree resolution, nested in an existing Global Ocean global Model, Mercator PSY4, at a resolution of 1/12 degree, with high resolution atmospheric forcing (every 3 hours).

The simulation outputs will be the 3 dimensional structure of the velocity fields (u,v,w) at 50 vertical levels over the water column, including geostrophic, Ekman and tidal currents, together with Temperature, Salinity and sea surface height at a sub-mesoscale spatial resolution.

Simulations will run in hindcast, nowcast and forecast modes, with a temporal resolution of at least 3 hours.

The Applications:

This Ocean current model will allow to perform detailed statistical studies on various areas using conditions analysed using hindcast mode, short term operational condition prediction for various surface and subsea operations using real-time and Forecast capabilities.

The First Results & Conclusion:

The paper will present the first publication of significant results of the project, in term of pre-sal zoomed model implementation, and high resolution model validation.

Significance

This project demonstrate the feasibility of obtaining accurate information for engineering studies and operational conditions, based on a "zoom technique" starting from global ocean models. Application can be transposed to any other area of interest such as GOM, North of the Golfe of Guinea (Nigeria, Ivory Coast, Ghana, etc.)
Real Time Horizontal Well Monitoring Using Distributed Temperature Sensing (DTS) Technology
Authors: Wang Xiaowei , Bussear Terry R.
Published: October 2011

The emergence of downhole distributed temperature sensing (DTS) technology has led to much better instrumented wells, allowing operators access to real-time temperature data leading to better well control and more efficient field management.

This paper will use field examples to demonstrate the benefits of this technology in two different applications: fracture monitoring during open-hole frac-stage treatment and steam distribution during Steam-Assisted Gravity Drainage (SAGD) process.

The migration from conventional cemented liner plug-and-perf techniques to packer-only stage isolation in open-hole has had a significant impact on the economics and efficiency of shale completions operations. As in-pay horizontal lengths get longer and the desire for increased unit fracture density increases, the concern for effective frac stage isolation increases.

The SAGD process has been widely used in thermal recovery industry for its high recovery efficiency. Effective steam utilization requires proper understanding of steam distribution along the targeted horizontal section.

Examples shown in this paper demonstrate the following benefits afforded to operators with access to DTS data in real time:Determine the effectiveness of open-hole frac-stage treatment during fracturing;View the movement of frac-fluids downhole within the target frac stage during fracturing;View the movement of fluids in previously fractured (lower) intervals during upper stage fracturing operations; andTemperature distribution along the well paths (injectors and/or producers).

Collected DTS data can also be analyzed in real time using in-house software tools developed for DTS visualization and interpretation. Data analysis and lessons learned from field applications are presented in this paper and focus on following four areas:Approximation of fracturing fluid distributionIntegrity of isolation packersImprovement in understanding of steam distributionImprovement of well integrity and identification of potential well completion breaches

Introduction

Distributed Temperature Sensing (DTS) is becoming an increasingly valued monitoring techniques when applied downhole in oil and gas applications. Acceptance has grown as a result of the increasing value that can be realized from such repeated, high-resolution well temperature profiles. Comparing with conventional production logging in horizontal wells, DTS technology is cost-effective and less risky. Unlike a conventional production log that provides only snapshots of the well performance, DTS can provide continuous real-time monitoring along the entire wellbore. Small temperature change can be easily detected by DTS. Such information can help operators to better understand their wells and reservoirs.
The Advancements of FEA in Confronting the Deepwater Pipelines Under High Pressure and High Temperature
Authors: Sun Jason , Jukes Paul , Wang James
Published: October 2011

This paper gives an overview of the latest developments of advanced finite element analysis (FEA) tools that are used for the design of subsea pipelines. It focuses on the deepwater and high pressure / high temperature conditions. The paper demonstrates through the use of FEA, that designs can be undertaken for complex scenarios that were not previously possible.

This paper includes three main sections. The first section looks at the ‘global’ analysis of pipelines using a set of highly non-linear finite element programs based on ABAQUS. These programs have been widely utilized for over ten years in oil and gas industry and for hundreds of field developments around the world, in various design stages, from pre-FEED, FEED, to final detail design. The programs are used to undertake the complex design cases, such as lateral buckling, upheaval buckling, pipeline walking; pipe-in-pipe (PIP); thermal buckle management; and pipeline span identification, as well as span stress and collapse screening. The programs have been calibrated against the observed pipeline structural responses in the field. The simulation process covers from installation to operation and can be expanded to pipeline span analysis, route curve stability, and pressure-thermal load fatigue assessment.

The second section demonstrates how FEA can be used to undertake ‘local’ modeling of pipelines to address local issues and provide verification and support for a reliable global pipeline design. Pipeline end structure behavior, thermal mitigation buoyancy and soil interaction, thermal mitigation sleeper embedment and installation tolerance, PIP inner pipe lock-in load, field joint stress/strain localization, and free span VIV analysis, are some typical applications. These works can be in component level or represent some local pipeline section. Such detail analyses ultimately relies on the ‘global’ FEA to provide trustworthy loading and boundary conditions.

This paper also presents the analysis strategies based on the project experiences, the lessons learned, and future improvement. The presentations include, the route selection versus thermal expansion and global buckling, the FEA modeling process (1-D, 2-D versus 3-D), the pipeline-soil interaction, the selection of mitigation for lateral buckling, and related design issues. The combination of these analysis advancements and extensive project experiences will provide the strong supports on solving the most complex engineering problems presently faced in the offshore industry, and in some cases have allowed significant cost savings to be achieved in the engineering.
An In-Situ Flow Cell To Highlight Different Mechanisms Of CaCO3 Inhibition By Green And Non Green Polymers
Authors: Duchene Aurelie , Neville Anne , Euvrard Myriam
Published: October 2011

Antiscaling agents are widely used to prevent scale formation in the oil and gas industry because scale's presence can lead to unscheduled shutdown and deferred oil production. The main problems result from the formation of scale on equipment. It has been shown that the mechanism of scale formation differed according to the scale nucleation that occurred in the bulk solution or on a surface.

The scope of this paper is to show, from experimental data, the effects of three different antiscalants on the growth rate of CaCO3 formation on a metal surface. The choice of which inhibitors to study was based on a survey of the environmental regulations that can be encountered in different parts of the world. A conventional phosphorous inhibitor was used as a reference (polyphosphinocarboxylic acid, PPCA) and contrasted to the performance of two environmentally friendly inhibitors (polymaleic acid, PMA, and carboxymethyl inulin, CMI).

The use of an in situ flow cell coupled with a video assembly and a microscope permits the real-time visualization of crystal morphology. Studies included looking at the surface coverage of the calcareous deposit and the number of crystals of CaCO3 formed. The effects of the scale inhibitors on the growth of calcium carbonate were studied after nucleation had occurred, in order to determine the effects of the inhibitors on calcium carbonate crystals already formed. A previous study was focused on the assessment of the inhibitors on the nucleation and growth steps. This paper is focused on the effects of the scale inhibitors on growing crystals which have been formed on a surface under uninhibited conditions.

The morphology of the crystals was found to be modified by the three inhibitors studied but to different extents. The addition of 4 ppm of PPCA and PMA significantly decreased the growth rate of the calcium carbonate crystals but the CMI did not modify it at the concentration range tested. This technique demonstrates that the efficiencies of scale inhibitors can vary according to the step in which the antiscalants were added (nucleation/growth).

Introduction

In the oil and gas industry, salts deposition is a problem widely studied because the presence of scale can lead to a loss of production, to formation damage and to the weakening of the equipment installations. Salts precipitation occurs when a system is not at ionic equilibrium. The equilibrium can be lost because of the changes of the temperature and pressure or with the introduction of incompatible brine. The supersaturation ratio S, characterizes the thermodynamic conditions of a solution and the equilibrium is reached when S is equal to 1.
Holistic Approach to Subsea Integrity Management & Reliability and their Application to Greenfield and Brownfield Projects
Authors: Botto Adriana , Rees Jacqueline , Hull Meghan
Published: October 2011

Industry momentum in recent years has been towards the implementation of risk-based integrity management (IM) programs for entire subsea systems (where subsea systems emcompass all hardware from the sand face downhole, to the top of the riser, inclusive of system interfaces, as defined in API RP 17N). This is evident from industry initiatives such as the Subsea Systems Integrity Management JIP (SURF IM JIP) and proposed revisions to industry codes of practice such as ISO 13628/12 "Dynamic Risers for Floating Production Installations" and API RP 17N "Subsea Production System Reliability and Technical Risk Management".

This paper presents a holistic approach to the development of risk-based integrity management programs, consistent with current industry best practice and JIPs that have advanced technology in these areas. The methodology balances the risk-based approach to maintaining asset integrity of the system as a whole with the reliability-based approach often adopted to define the preventative maintenance and sparing strategies for subcomponents of the subsea system.

A risk-based approach to integrity management is typically focused on identifying the IM measures required to manage the risk of catastrophic system failures with adverse safety, environmental, operational or reputational consequences. Reliability methods, in contrast, are typically focused on mitigation or preventative maintenance to avoid the unplanned failure of an asset's subcomponents (e.g. mechanical or electrical subsystems), the failure of which typically would not on their own lead to full system failure. A holistic IM program identifies the inspection, monitoring, analysis, procedural and preventative maintenance measures advocated to manage the integrity of the subsea system in its' entirety, balancing risk-based integrity management with reliability-centered maintenance.

The authors will demonstrate the implementation of this methodology for greenfield and brownfield projects (from the conceptual stage through to decommissioning). Emphasis is placed on how the integrity needs of a system mature over its lifetime to ensure a continuous, practical IM program.
Post-Macondo BOP Safety Upgrades
Authors: Baugh Benton F. , Vozniak John , Schmidt Nathan
Published: October 2011

In the pre-Macondo blowout era the offshore industry had an impressive record of safety, especially considering the complexity and magnitude of the work being done in relatively harsh conditions. The failures and spillages of Macondo have indicated that there are a number of safety areas which have not received appropriate progress in large part because history had not experienced a major failure of a BOP stack at that depth of water. This paper addresses several areas of technology which can be implemented to increase safety on new deepwater drilling BOP systems or retrofitted on current BOP systems in the field. These safety areas include better use of accumulator capacity, greater control over BOP stack functions, more redundancy of control, and improved ability to shear wellbore components. The ready availability of these safety upgrades and methods for full BOP Subsea operation and control, high volume ROV operations, and shearing drilling collars represent significant upgrades to Subsea drilling equipment safety systems post Macondo.

Depth Compensated Accumulators

Depth compensated accumulators represent a major safety improvement post-Macondo, although they were already seeing market acceptance before Macondo. The problem with accumulators on Subsea stacks is that more than 100 accumulator bottles would be needed instead of approximately seven for the depth compensated version1. Additionally, the depth compensated accumulators can be retrofitted on the ocean bottom by using multiple frictionless controls, also a major safety upgrade presented later in this paper.

The basic concept as seen in figure 1 is that a dumbbell piston has pressurized nitrogen in the top chamber and working fluid immediately below in a second chamber. The second chamber is divided from the third chamber by a central, stationary bulkhead. The third chamber is pressurized with environmental pressure, typically through an intermediate fluid for corrosion reasons. The fourth lower chamber is basically empty or a vacuum. This means that the pressure in the third chamber is not supported from below, but rather is mechanically added to the pressure in the second chamber. This means that at any depth, the pressure in the second working chamber exceeds environmental pressure by the amount of the nitrogen charge.

Increased safety impacts of depth compensating accumulators are:High nitrogen (or helium) pressures associated with conventional accumulators in deepwater situations are not required. As the piston area in chamber 2 is slightly less than the area in chamber 1, the nitrogen pressure never exceeds the working fluid pressure.Complex calculations are eliminated, the accumulators are simply run and operate subsea similarly as they operate on the surface.When the accumulator comes to the surface, dumping the nitrogen in the accumulators is not required.When the accumulator is re-run, the nitrogen does not have to be recharged,There is no danger that only some of the nitrogen banks have been recharged, but not all of them.
Deep Water High Capacity Dynamic Power Cables; Recent Developments
Authors: Brown David , Patel Darren , Rossiter Steve
Published: October 2011

The design, installation and operation of offshore high power static (seabed) cables are mature technology areas. However, the key missing component in the power transmission system is the water-column portion of the cable that links the floating facility with the static cable on the seabed, the electrical equivalent of a pipeline riser. When such dynamic power cable enabling technology matures it will allow the removal of power generation equipment from platforms, interconnection between offshore installations, utilization of stranded gas for power generation (GTW - Gas to Wire) and its transmission by subsea power networks to the customer, and the transmission to land of power from offshore deep water renewable energy devices.

This paper reviews recent developments in dynamic power cable technology. It discusses the range of configurations and technical requirements required to deliver a fit-for-purpose deep-water product. In particular, mechanical fatigue is addressed together with the need for field specific designs to optimize configurations. Conclusions from the PowerCab JIP recently completed by BPP-Cables are presented. The JIP delivered a prototype 100MW 132kV dynamic AC power cable optimized for extended service life with account taken of the manufacturing and installation issues. The cable has been fatigue tested to verify electrical and mechanical performance in conditions representative of the West of Shetlands.

Introduction

In recent years, there has been a significant increase in the need to transmit subsea electrical power over greater distances at higher power ratings and in ever more challenging environments. A key component of the required technology is the water column power cable, which must be electrically, and mechanically fit-for-purpose throughout the field life. This paper gives an overview of the recent developments in high voltage power cable engineering with respect to dynamic deep-water applications. In addition, the design drivers in relation to the failure modes of subsea power cables and umbilicals are presented. Further, the various associated technology developments are briefly reviewed.

Typically, four modes of operation are involved, as described below:–from shore to floating platform

There is a growing need to transmit power from shore to offshore developments. This is primarily to reduce the total CO2 output for a given project in countries such as Norway, where the onshore electricity supply is generated from low-carbon technologies such as hydroelectric, replacing inefficient offshore generators to yield significant CO2 and cost reductions.
Improved NPV Using Shallow Water Subsea Systems to Achieve Early First Oil and Reduce CAPEX
Authors: Streeter Jerry , Moody Ryan Philip
Published: October 2011

The conventional practice for developing shallow water oil and gas fields is to install a bottom-founded structure over a drill center, then mobilize a jack-up drilling rig for drilling and completion operations. While this is a time-tested and proven method of producing hydrocarbons, it often does not provide the owner with the best investment economics. This is especially true for brownfield projects where the production capacity of existing infrastructure can readily accommodate new production. These economics are affected by multiple factors including the cost of drilling deviated wells compared to vertical or near vertical wells, time to production, and salvage costs.

Shallow water subsea production systems (SWSPS) are also a time-tested, reliable production technology. Installed on wells equipped with mud-line suspension systems, SWSPS provide advantages in many ways. Because they enable the use of a vertical wellbore positioned directly over the reservoir objective, SWSPS shorten drilling times by eliminating the need for highly deviated or directional wells. As compared to a conventional platform, a shallow water system can greatly improve field economics as measured by net present value (NPV) through many cost-savings features that shorten time to first oil, lower installation costs, and reduce abandonment and salvage costs.

This paper examines three modeled Gulf of Mexico oil developments located in less than 100 meters of water to demonstrate the importance that candidate selection has in maximizing NPV, and how subsea technology specifically designed for a shallow water environment is able to turn a marginal or uneconomic field into an economical development.

Introduction

Compared to deep water subsea production systems, relatively little has been published on shallow water subsea production systems (SWSPS) even though they were the foundation used to develop deep water subsea production systems. The large number of SWSPS in place world-wide, and their many years of successful operation, demonstrates the reliability that can be obtained with this equipment. SWSPS are being seriously considered by many operators to improve asset economics by enabling individual wells to be tied back to the existing platform infrastructure.

The key components of a shallow water system consist of a subsea tree fitted with a net guard (where required), the flowline and umbilical, risers, a production manifold (not shown) and a control system, Figure 1.
DOFT for Monitoring and Optimization of the First Ultra Deepwater FPSO Production in the GoM
Authors: Zambare Neeraj , Coronado Oscar , Reon Greg , Santos Luiz Guilherme
Published: October 2011

The Digital Oil Fields Tool (DOFT) for the Cascade and Chinook fields, located in GoM, is a self-learning dynamic model available 24/7. Topsides process simulator, D-SPICETM, was integrated with a multi-phase pipeline simulator to develop the DOFT. A stable interface allows high-fidelity simulations for subsea pipelines together with topsides facilities. The DOFT model scope covers the subsea wells, flowlines, subsea boosting pumps, inlet heaters, separators, gas export flow lines and pigging.

The DOFT includes four modes. The Real-time (on-line) and Look-ahead (off-line) modes are used to monitor operations throughout the process. Functionalities include monitoring of hydrate margins, tracking of various chemicals, liquid/gas holdup monitoring, virtual flow metering, and leak detection among others. The Planning simulator (off-line) is used for detailed diagnosis of problems, analyzing "what if" scenarios, and planning critical operations. The Training mode (off-line) is used to familiarize the operators with everyday operations without risking the real production facility.

The Real-time simulator and the data historian are linked via a unidirectional OPC link in order to get required "live" measurements. Wherever available, real-time and simulated data are presented together for comparison. Current real-time condition of the DOFT can be transferred to the Planning simulator for off-line planning simulations. Look-ahead scenarios can be run on the Real-time simulator which displays "future" trends which warn of impending problems. Speed of at least 36 times real time can be achieved in the Look-head and Planning modes.

There are numerous advantages of a system like DOFT such as verifying operating procedures, training operators, monitoring the process in real-time, performing engineering studies, helping in decision making for day-to-day operations, helping find mistakes in P&IDs, operator screens and shutdown and interlock logic. The DOFT has already been verified by a third-party to be a useful tool to prepare and check operating procedures for this project. It is beyond doubt that production in deep and ultra deep waters is extremely challenging, and hence the use of systems like DOFT is becoming more and more important.
Development of a New Generation of Innovative Synthetic Wire Mooring Ropes
Authors: Mohanraj Jagan , Cawthorne Stephen , Calverley Stephen , Fletcher Sara Louise , Verwaayen Johannes
Published: October 2011

The paper outlines the latest stages into the research and development of an innovative new material for offshore floating system mooring ropes. This new material combines the benefits of robust steel solutions with the lighter weight of polyester fibre ropes. In this paper the experimental sample assessments and full scale production prototype developments are presented. Floating production systems are being located in ever challenging environments. Deeper waters and increasing environmental loads require station keeping systems to offer optimum performance. Traditional materials are reaching their natural limitations, requiring innovative solutions to ensure performance in critical locations - control of weight and extension to achieve cost effective station keeping.

With support from industry and academic partners, a methodology for manufacture of high strength polymer wire at economically viable production speeds has been established. The material has been selected for its high strength, light weight, low creep characteristics, to achieve suitable base properties for a stable strength member.

The resultant wire exhibits dimensional and performance characteristic suitable for use within traditional wire rope constructions. This allows efficiencies in manufacturing, including health and safety advantages, and assessment of design performance, benchmarking achievements with well known performance data. This material allows for additional R&D opportunities in other more novel constructions and combinations.

Investigation and development of a termination medium and methodology specific to the synthetic wire rope has been a challenge which has been ably met. Understanding the impact of traditional methods and materials on rope properties has been investigated, new materials and methods developed to ensure a robust, 100% efficient and repeatable socketed solution.

Through such reliable terminations, laboratory testing has generated a range of performance data allowing detailed assessment within taut, catenary and combination mooring systems.

A review of the current relevant international mooring component specification has been necessary to establish product specific testing parameters for potential pre-qualification prior to use. Development of a new product has required selection of the appropriate criteria to ensure the rope performance in operation; this has not necessarily mirrored the requirement for traditional components.

Ensuring efficient and economical station keeping in given locations is essential to realising the potential from these fields. Without development of leading edge mooring and station keeping some resources remain out of reach. Manufacturers of station keeping equipment supplying to the offshore industry are constantly investigating and developing solutions to support the move of exploration and production to ever more extreme locations.
Use Of Safety Case To Accomplish With Brazilian Regulations For Drilling Units
Authors: Bardy Mariana , Silveira Paula Dias , Sodré Felipe
Published: October 2011

The growing operation of foreign oil and gas production and drilling units in Brazilian waters requires special attention to the Brazilian legislation requirements concerning health, safety and environment. Based on this aspect it is essential to an evaluation of Brazilian law applied, especially in relation to requirements established by the National Agency of Petroleum, Natural Gas and Biofuels (ANP), through Resolution Nº. 43 establishing the Operational Safety Management System (SGSO - "Sistema de Gestão de Segurança Operacional"), compared to international requirements and development of Safety Cases, which are grounded in brief guide for the IADC - International Association of Drilling Contractors called Health, Safety and Environment Case Guidelines for Mobile Offshore Drilling Units. This comparison allows us to assess whether the Safety Case can be used as a basis for compliance with the ANP requirements and whether there are additional requirements that must be in according to.

1. Introduction

Given the presence of a large number of foreign companies interested in drilling operations in Brazilian waters and the extensive requirements of Brazilian legislation concerning health, safety and environment, this work aims to verify the contents of the Safety Case proposed by IADC- International Association of Drilling Contractors, meets the requirements of Brazilian legislation, specifically the ANP for the drilling unit.

The National Agency of Petroleum, Natural Gas and Biofuels (ANP) is the regulator of activities that integrate the industry of petroleum and natural gas and biofuels in Brazil. It aims to promote the regulation, contracting and monitoring of economic activities in the petroleum industry, in accordance with the legislation, the guidelines issued by the National Energy Policy Council - herewith and in accordance with the interests of the country.

The development of Safety Cases is based on the guide IADC - International Association of Drilling Contractors called Health, Safety and Environment Case Guidelines for Mobile Offshore Drilling Units. This guide provides the minimum requirements for the development of a Safety Case According to the IADC, such as Description of the Unit, HSE management system, Risk Management, Emergency Response and Performance Monitoring.

The ANP through Resolution No. 43 establishing an Operation Safety Management System (SGSO) for Drilling and Production Vessels of Oil and Natural Gas, aims the maintenance of safety in offshore facilities, in order to protect human life and the environment through the adoption of 17 management practices.

The main objective of this paper is to compare the minimum content of a Safety Case developed using IADC Guidelines with the requirements of the ANP, and establish if the Safety Case can be used as a basis for meeting the requirements of SGSO of ANP and verify if additional items are needed for the latter based on their technical regulation.
Evaluation of The Seismic Time-Lapse Acquisition Period In Reservoir Monitoring
Authors: Ferreira Carla Janaina , Davolio Alessandra , Maschio Celio , Schiozer Denis Jose
Published: October 2011

Time-lapse seismic is an important tool for reservoir management, assisting in the mapping of flooded areas, injection fronts and faults identification. This technology enables a better understanding of the geological model and the fluid flow and is another data source for reservoir management. Several published cases report the successful use of this technology in reservoir management to increase production efficiency; however, in order to gain commercial advantage, it is necessary to identify the moment at which to start the seismic monitoring project. This moment cannot be too early, because the seismic may not be able to identify variations in the reservoir dynamic properties and it cannot be too late because major changes may not be detected and it can be too late for effective action in field management. However, the quantitative assessment of the 4D seismic value is based on simulation models, used to predict the production, with and without seismic acquisition, and there are many uncertainties in the forecasting process in the field development phase. Therefore, in order to ascertain the period of 4D seismic acquisition that allows for an increase in production efficiency and reduces field uncertainties, a study was done to show the effect of 4D seismic at different production times for a simple synthetic case aiming to illustrate the concept of 4D seismic evaluation. Synthetic seismic data were generated from a reference model for several production times and performed the history matching of the simulation model (base model) with production and 4D seismic data.
Pre-Commissioning of First Interfield Pipline of Brazilian Pre-Salt Projects
Authors: Feitosa Sergio Ricardo , Estites Carlos , Everard John
Published: October 2011

Aside from the huge production potential of the Brazilian deep water, pre-salt reservoirs, the technical, operational and management challenges in this harsh environment have driven the largest engineering, construction and service companies to acommon goal: To meet the nation's expectations of continuing the rates of growth in the Oil and Gas industry that raise thecountry to its place as one of the world's leaders in energy production.

When asked to undertake the task of certification and pre-commissioning of the first wet-end to wet-end gas pipelines running between the first large scale pre-salt production fields, Weatherford realized they had come into a Brazilian historical challenge. The Uruguá and Tupi gas pipelines figure to be some of the largest in the world in terms of fill volume and water depth: 18?? x174km with the deep end of the system located from 1300 meters (Uruguá) to 2200 meters (Tupi) equivalent to 4200 to 7200 feetrespectively below sea level.

The Uruguá gas pipeline project was successfully managed engineered and executed by our local staff in Brazil and was the majorproject that was given completely to the local group. The integrated scope of work included for flooding, cleaning, gauging, caliper pigging, hydrotesting, dewatering, conditioning and nitrogen purging of the entire pipeline system at once. AWeatherford designed and fabricated caliper pig was modified to be able to run bi-directionally. For the hydrotesting activities, Weatherford also designed and built subsea dataloggers for use in extreme deep water with a ROV friendly self-standing support while Saipem purchased and operated a 3?? ID 1600 m long non-collapsible downline in order to be able to dewater the pipeline.

All activities were completed while working together with our client Saipem, within the pre-commissioning schedule, in strict accordance with all Petrobras requirements and under the close supervision of DNV, who provided the project certification. Two Saipem vessels, Chloé Candy and Normand Cutter, were involved in the entire project duration.

All of the equipment required to meet the entire project parameters for pig speed and pressurization were taken from Weatherford Brazilian fleet. All phases of the project were undertaken using best practices and standards for quality, health, safety and environment. There were zero safety and environmental incidents recorded for this project.

Pre-commissioning activities were successfully completed for the Uruguá project by Saipem and Weatherford between the 14th of April and the 23rd of September, 2010.
Dual Coil - Long Offset, Full Azimuth Marine Towed Streamer Acquisition
Authors: Bunting Timothy John , Moldoveanu Nick , Brice Tim
Published: October 2011

Driven, primarily, by the desire to image sub salt targets in the GOM, the industry has made significant improvements in towed streamer acquisition technology, to improve imaging through complex over-burdens. This paper will review a new towed streamer technique which makes a full azimuth seismic measurement with ultra-long offsets (14,000m), which was designed to mitigate imaging limitations of the commonly used WAZ designs in the US GOM. The final design was based on a very intensive modeling study, on real and synthetic models, using a finite difference modeling approach.

Introduction

As the "easy to produce" hydrocarbon reservoirs become more sparse, the industry is exploring in more challenging areas such as deep water, pre-salt, sub basalt etc.. The complexity of these geologies significantly increases the seismic imaging challenges. Conventional marine towed streamer (NAZ) acquires a very limited azimuth range because of the long/thin geometry of the surface receiver spread. While the source generates a wavefield which propogates in all directions, the receiver spread only records a very limited proportion of the reflected wavefield. If the target and over burden geology is relatively benign (low dip and homogeneous) even this limited spread can illuminate the reservoir reasonably consistently. However, if the target and overburden geology is complex, the seismic rays will bend and scatter on their way to and from the reservoir, resulting in inconsistent illumination. Over the last ten years the industry has developed towed marine solutions which generate a more diverse set of ray paths by more fully sampling the azimuth range, which consequently more evenly illuminate target reservoirs in geologically complex areas.

These techniques include multi-azimuth (MAZ), wide-azimuth (WAZ), rich-azimuth (RAZ) and more recently Coil Shooting. MAZ is a technique in which a conventional NAZ survey is acquired multiple times using different primary orientations; Generally, the data is merged post stack either using a weighted or unit summation. WAZ is a technique in which multiple vessels are used to extend the range of azimuths collected and RAZ itechnique in which WAZ geometry surveys are repeated in multiple acquisition directions.

Coil Shooting is a technique in which a marine towed streamer vessel follows a circular pre-plot. This circular line is then repeated in the inline and crossline direction, to build up fold, offset distribution and azimuth distribution. As well as acquiring a dataset very well sampled in azimuth, the technique benefits from some acquisition efficiencies associated with the very sdowntime (line change) between circular lines. This downtime is of the order of minutes as opposed to hours for conventional race-track acquisition.