bluuebunny/crossref_metadata_2025 huggingface dataset:
RADIOLOGICAL ASSESSMENT OF IONIZING RADIATION IMPACT ON THE TERRESTRIAL NON-HUMAN BIOTA IN LITHUANIA
Authors: KONSTANTINOVA Marina , PROKOPČIUK Nina , GUDELIS Arūnas , BUTKUS Donatas
Published: October 2015

The quantitative assessment of radionuclides transfer to non-human biota using their activity concentration ratios is required for models of predictive doses of ionizing radiation. Based on long-term data regarding activity concentration of radionuclides in the top soil layer of the entire territory of Lithuania, and with the help of ERICA Assessment Tool – a software application that calculates dose rates to selected biota, we estimated the radiological impact on the terrestrial non-human biota with special emphasis on the protected areas located in the vicinity of Ignalina Nuclear Power Plant (INPP). Estimated total dose rates of artificial radionuclides – after-Chernobyl 137Cs and 90Sr as well as discharged by INPP – and natural radionuclides, such as 238U and 232Th, were found to be less than ERICA screening value of 10 μGy h–1.
Replacement of soybean cake by Hermetia illucens meal in diets for layers
Authors: Maurer V. , Holinger M. , Amsler Z. , Früh B. , Wohlfahrt J. , Stamer A. , Leiber F.
Published: October 2015

Insects will likely play an important role as protein sources for livestock in the future. Many insect species are able to convert materials not suitable for human nutrition – or even waste – into valuable protein with a favourable amino acid composition for poultry and other livestock. A feeding trial with partly de-fatted meal of dried Hermetia illucens larvae (Hermetia meal) reared on vegetarian by-products of the pasta and convenience food industry was carried out in small groups of Lohmann Selected Leghorn laying hens (four rounds, 10 hens/round). Experimental diets H12 and H24 contained 12 and 24 g/100 g Hermetia meal replacing 50 or 100% of soybean cake used in the control feed, respectively. After three weeks of feeding experimental diets, there were no significant differences between feeding groups with regard to performance (egg production, feed intake). There was a tendency (P=0.06) for lower albumen weight in the H24 group; yolk and shell weights did not differ. No mortality and no sign of health disorders occurred. Plumage as well as wound scores remained stable during the feeding period and did not differ between treatments. Dry matter of faeces increased with increasing proportions of Hermetia meal in the diet, with a significant difference between H24 and the control (P=0.03). An increase of black faecal pads was observed in the H12 and H24 groups. Overall, these results suggest Hermetia meal can be a valuable component of layer diets. However, insect meal production still has to become economically more viable through upscaling production and, especially, legislative issues have to be solved.
Toward Assessment of Dementia Caregiver Activation for Health Care: An Integrative Review of Related Constructs and Measures
Authors: Sadak Tatiana , Souza Anita , Borson Soo
Published: October 2015

The purpose of this integrative literature review was to establish the rationale for a new measure of dementia caregiver activation for health care. Little is known about how caregivers form working partnerships with clinicians to manage the health of individuals who, because of cognitive impairment and functional limitations, can no longer actively manage their own health. Building on three sources—the construct of patient activation, an empirical health care framework for individuals living with dementia, and a set of dementia care quality indicators—the construct of dementia caregiver activation for health care was defined and initial relevant domains were specified. An integrative literature review was performed to identify related constructs and assess currently available measures with respect to their inclusion of these key health care domains. Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, 647 citations were reviewed and reduced to 17 studies, which were included in the analysis and qualitative synthesis. No existing measure was found that captures all of the domains required for caregiver–clinician partnership, establishing the need for a novel measure of caregiver activation focused on the health care of individuals living with dementia.

[Res Gerontol Nurs. 2016; 9(3):145–155.]
Robust Background Modeling with Kernel Density Estimation
Authors: Hua Man , Li Yanling , Luo Yinhui
Published: October 2015

Modeling background and segmenting moving objects are significant techniques for video surveillance and other video processing applications. In this paper, we proposed a novel adaptive approach modeling background and segmenting moving object with non-parametric kernel density estimation. Unlike previous approaches to object detection which detect objects by global threshold, we use a local threshold to reflect temporal persistence. With combined of global threshold and local thresholds, the proposed approach can handle scenes containing gradual illumination variations and noise and has no bootstrapping limitations. Experimental results on different types of videos demonstrate the utility and performance of the proposed approach.
Fuzzy PID Temperature Control System Design Based on Single Chip Microcomputer
Authors: Xie Xiaolan , Long Zhen
Published: October 2015

In order to solve oil drilling crew's VFD (Variable Frequency Drive) room can't make air conditioning to cool the equipment problems cause of diesel generator fails suddenly stop power supply, this paper introduces the hardware and software design based on the constant temperature system of the STC89C52 SCM and carries out the simulation through MATLAB so as to compare and analyze the fuzzy self-turning PID control results and traditional PID control simulation results. The experimental results show that this design can realize the SCM constant temperature control of fuzzy PID algorithm.
Small Size Specimens Methods for Evaluation of Mechanical Properties
Authors: Rund Martin , Volák Josef , Šindelářová Miroslava
Published: October 2015

The evaluation of actual mechanical properties of the in-service structures after some time of operation or determination of local properties for detailed FEM simulation yields the necessity to obtain relevant material data with high accuracy from small volume of the experimental material. Therefore, non-destructive or semi-destructive techniques using small size samples are being developed. The use of small-scale samples also enables the evaluation of material properties in various locations of tested component; for example, the mechanical properties of the individual regions of welds, local properties determination for properties anisotropy assessment and properties determination in cases when small volume of the experimental material is available e.g. residual service life assessment of in service components, bulk nanostructured materials… There are shown results of small size tensile tests (M-TT) and small sized fatigue tests (SFT). In the case of small size specimens testing a machining becomes more pronounced that in the case of standard sized specimens. The current study brings information on the machining influence on the expected results obtained by small size specimens in the case of quasi-static tensile tests and fatigue test.
Finite-Element Simulation of the Process of Lengthwise Pipe Rolling on a Stub Mandrel
Authors: Bogatov Alexander A. , Pavlov Dmitriy A. , Dresvyankina Elena A.
Published: October 2015

The improvement of the technology of pipe production on a lengthwise rolling mill is proposed. The investigations are carried out on the basis of a lengthwise rolling mill installed at the “Sinarsky Pipe Works” Open Joint-Stock Company. The aim is to master the whole range of production from continuous castings on the existing equipment, as well as to exclude 120 mm diameter rolled workpiece from the production in order to reduce production costs. An increase in the elongation ratio on a lengthwise rolling mill is necessary to master a continuous casting. Rough tube forming on a stub mandrel in a lengthwise rolling mill with rough tube preovalisation has been investigated with the application of the finite-element method. The behavior of the dimensionless parameters characterizing the deformation of the metal in the groove taper as dependent on the rough tube elongation ratio has been determined. The bite begins in the upper part of the groove when the oval rough tube is fed to the lengthwise rolling mill groove. Rough tube preovalisation provides uniform groove filling during lengthwise rolling on a tapered stub mandrel. Besides, it provides a decrease in the intensity of rough tube wall thickening in the groove taper during lengthwise rolling. This enables one to avoid the formation of a “guide mark” defect on the inner surface. The ratio of the longer axis of the rough tube oval cross section to the minor axis must range between 1.15 and 1.25. The rough tube preovalisation before lengthwise rolling provides an opportunity to increase elongation ratio at the lengthwise rolling mill from 1.45 to 2.00.
Keywords:
A tube rolling-off; a stub mandrel; an automatic mill “tandem”; a finite-element simulation; a coefficient of rough tube ovalisation.
Possibilities of Use of the Thermographic Measurement as a Tool for Detecting Defects and Improving the Production Process
Authors: Rykalová Eva , Peřina Zdeněk , Fabian Radek , Jonšta Petr
Published: October 2015

Infrared radiometric long-waved systems are widely used in various industries as well as in research and development. This long-waved system is the perfect tool for quick diagnosis of the state of the equipment, easy defect detection, which is reflected by higher temperatures due to increased friction and wear. Infrared radiometric long-waved systems are used especially in civil engineering, electrical engineering, metallurgy and many other industries. They are also used to optimize and improve of the production processes. The series of measurements using the infrared radiometric long-waved system in steel plant were carried out due to prepared research project. Images of temperature fields of ladles with liquid steel, cooled exhaust knee of electric arc furnace and ingot mould were obtained during solidification of steel ingot. Information about the state of wear of the refractory lining of the ladle, exhaust knee can be gained from obtained images. The obtained results can be used for more accurate numerical simulations of the process of casting and solidification of steel ingots.
Investigation of Steel 09G2S Processed by Equal Channel Angular Pressing
Authors: Borisova Maria Z. , Yakovleva Sofia , Makharova Susanna N.
Published: October 2015

Severe plastic deformation is a well known procedure for fabrication considerable grain refinement in metal materials. Equal channel angular pressing (ECAP) is one of these severe plastic deformation techniques which allows the receiving of the bulk ultrafine grained (UFG) metals. It is well known that the ECAP method leads to significant improvement of strength of investigated materials, but the fracture mechanisms of UFG metals at low temperature are not enough studied. The investigation was performed on low-alloy constructional steel 09G2S (GOST) after application of ECAP. Fracture toughness tests were performed on Charpy impact testing specimens at low temperature. The experiments demonstrate that ECAP treatment has the effect on increasing of fracture resistance of steel 09G2S at low temperature.
Software Quality Standards for the Offshore Industry
Authors: Card David N.
Published: October 2015

This article explores the status of software quality standards development and application related to the maritime and offshore industry. This article summarizes the standards currently in use, as well as trends. Recent experience with high specification drilling vessels indicates that undependable software contributes significantly to operational down-time and loss of revenue for operators. This article introduces a framework for examination of software quality, including process product, operational, and customer perspectives. This article focuses on software process quality. Getting the software right the first time is much cheaper than testing and fixing it to acceptability. The cost of rework for a typical software development project ranges from 20% to 50% of total project costs. This article identifies some common software process reference models and explains how they help to achieve software quality. While, there is no specific national or international regulation addressing Software Quality Assurance (SQA) in the Maritime and Offshore industry, some recommendations and guidelines have emerged recently. Three classification societies (DNV GL, ABS, and LR) have published software process reference models (standards) as optional rules for offshore vessels. These standards are based on widely accepted ISO/IEC standards that have been endorsed by national standards bodies. Regulations and liability concerns will eventually force the maritime and offshore industry to accept greater requirements for software quality assurance, as has happened in other major industries. For now, if a customer wants quality, he/she must ask for it. These new optional standards make that easier.
Unique Hybrid Drill Bit with Novel PDC Cutters Improves Performance in Ultra-Deepwater Brazil Pre-Salt Application
Authors: Oliveira G. D. , Freesz M. P. , Izbinski K. T. , Valbuena F. , Carvalho D. J. , Alonso A.
Published: October 2015

The Brazil ultra-deepwater, pre-salt application has been a very challenging drilling environment since exploration activity began in 2005. The initial pre-salt section contains limestone with random silicified nodules. Over the last few years, operators have collected large amounts of data for service companies to analyze to improve drilling performance through bit design. Using this information, a hybrid bit design with the most advanced cutter and bit technology was developed successfully increasing the distance drilled by 138% and the rate of penetration (ROP) by 171%.

Prior to advanced hybrid bit technology, a variety of other drill bit technologies such as polycrystalline diamond compact (PDC) bits and impregnated designs were used in the pre-salt. Historically, impregnated bits had longer runs, but with high mechanical specific energy (MSE) and low ROP, drilling with these bits was not economical. Contrarily, PDC bits can deliver higher ROP but cannot drill as far as impregnated bits. Three hybrid designs, the last one using dual-chamfer technology, were brought into this application to reduce cost-per-meter through better drilling efficiency and ROP. Each successive design managed to exceed customer expectations.

Extensive laboratory tests were conducted on the hybrid designs to address the demanding needs of pre-salt applications. These unique bits showed promising results on atmospheric surface rig tests and in pressurized bottomhole simulator testing. Hybrid bits produced much less torque, with smoother torque fluctuations and faster ROPs than roller-cone and PDC bits through the simulated interbedded formations in laboratory testing. Novel dual-chamfer cutters used in the bit have been lab tested on a vertical turret lathe (VTL), a visual pressurized single-point-cutter (VSPC) test machine and a monotonic loading test. Cutter testing showed positive VTL results and increased resistance to diamond fractures.

Ultra-deepwater drilling is very demanding and expensive, so operators want to achieve total depth in just one run by avoiding trips to change out the bit or bottomhole assembly (BHA). The improved bit and cutter technology resulted in significant cost savings and confidence for the customer. The performance of the hybrid bit with dual-chamfer cutters was significantly better than offsets, saving the operator approximately USD 9769/m.
Evaluation of New Technological Routes to Waste Treatment Generated on Oil Platform: Waste-to-Energy
Authors: Scorzelli I. B. , Costa C. L. P. , Furio P. R.
Published: October 2015

The aim of this study is to assess the state of the art of the hazardous waste treatment generated in offshore activities and propose innovative technological alternatives based on the principles of sustainable development, as the technology of plasma assisted gasification.

This study examines the waste generation from the FPSO platforms and compares the new technological routes with current market solutions from available data, showing the needs of the industries adopt clean technology where the process does not harm the environment and generates recyclable waste, can avoid the use of landfills, can be deployed anywhere and can even adapt to mobile units treating small quantities (minimum 1 ton / day).

Brazil has an environmental waste policy (Law No. 12,305 / 10) requesting that companies have programs to reduce generation avoiding the use of landfills and waste stations. In the case of FPSO platforms, the generation of hazardous waste is more than 54.3% of the total generated, where the main residues are drilling fluids from the ultra deepwater wells.

The current of Brazilian Solid Waste Policy defines the methodology of less impact on the environment disposal of waste. The first alternative is the post-consumer reverse logistic, where the waste generated has to be returned to their respective manufacturers of the products. And the last alternative to be used is de landfill, when the waste has not technological treatment available.

The results show that the waste generated in the platform are mostly intended for co-processing or landfill but the cost to transportation and treatment is high due the distance from the terminal ports. A new technological route, as plasma gasification, stands out by accepting a mixed of different types of waste (hazardous, medical, domestic, others) and produces vitrified slag as a byproduct that is inert and safe to use as aggregate or for use in other applications, as concrete products. The emissions from this sort of plant will be similar to a natural gas fired power plant and power can be produced, when the clean syngas is burned in a gas turbine or reciprocating engine, benn better than incenaration, that in Brazil does not have any kind of energy recover and can generates dioxins; furans and toxic ash if not well managed. The gasification plasma solution can be on of the emerging technologies to reduce environmental impacts, producing energy in a sustainable way from hazardous waste bringing economic and environmental benefits to the sector.
GTL FPSO & Modular GTL as Potential Solutions for Developing Offshore Oil & Gas Fields
Authors: Kwon H. , Choi D. , Moon Y. , Ahn S. , Jang N. , Lim H. , Kim W. , Denholm D. , Park T.
Published: October 2015

Growing global energy demands have led us to development of new oil & gas fields. In the meantime interest in eco-friendly solutions has been increasing in the area of stranded & associated gas fields. According to the BP report 2015, global natural gas reserves are approximately 6,607 tcf. Nearly half of that is assumed to be stranded & associated gas that is uneconomical for market delivery due to its remoteness from potential markets and lack of economic transportation, infrastructure and GTL conversion technology. Therefore, Daewoo Shipbuilding & Marine Engineering (DSME) has researched Gas-to-Liquids (GTL) Floating Production Storage and Offloading (FPSO) & Modular GTL as potential solutions for developing offshore oil & gas fields. Because products of the GTL process can be easily combined with crude oil in the Hull tanks and used in the existing energy infrastructure.

From a shipbuider's perspective, key design considerations in assessing onshore GTL technology for GTL FPSO & Modular GTL application were studied and analyzed as follows: Robustness to marine motion, Limited space, Weight and height, Self-sufficiency, Safety, Constructability and Certification Requirement. Moreover, commercial & demonstrated GTL technologies involved in Gas Treatment, Pre-Reformer, Reformer, Fischer-Tropsch Reactor, Upgrading and others were compared and reviewed to determine which technology is the best option for GTL FPSO & Modular GTL. Additionally, we have studied which GTL application method would be more competitive depending on the gas production size in offshore fields. Moreover, preliminary market analysis was performed to better define the scope of GTL products to be produced. Economic analysis was also performed to identify the major cost factors and understand their sensitivity on the project.

DSME has recently completed the feasibility study to acquire the preliminary design & engineering of GTL FPSO & Modular GTL for stranded gas & associated gas fields in offshore locations. The results of this feasibility study suggest that design concepts of GTL applications are technically practicable. The clean fuel and the chemical feedstock from the GTL process will be profitable in the markets and the design concept will be economically competitive within the range of the current project cost factors.

DSME hopes to set up a cooperative network with competitive companies for the next stage of GTL FPSO & Modular GTL. The cooperation network will implement at GTL FPSO & Modular GTL Pre-FEED and the economic study and will result in the commercial realization of this innovative approach for monetizing stranded & associated gas fields offshore.
Pre-Salt Limestone Plays in Campos and Santos Basins, Brazil: Additional Potential Identified
Authors: Kattah Senira
Published: October 2015

This study summarizes the pre-salt hydrocarbon play elements in Brazilian offshore and identifies additional exploration potential within the BMS-50/52 and BS-1_South 3D seismic surveys areas within the Santos Basin and of the BC-200 merged and reprocessed PSDM survey located within the deep to ultra-deep waters of the Campos Basin. Several large opportunities have been identified based on seismofacies recognition and preliminary seismic interpretations of 3D Multi-Client PSDM surveys.

The BMS-50/52 and BS-1_South 3D surveys are within the pre-salt play polygon of the Santos Basin. The pre-salt exploration trends identified in the these surveys are: a) Rift/Pre-rift play in the central-west, with hydrocarbon accumulations in siliciclastic reservoirs of the Paleozoic (pre-rift) to the Lower Cretaceous rift succession in fault traps; b) Sag/Rift Limestone Edge Play (Sagitário trend), comprising structural or paleo-topographic traps beneath the base salt in microbial platform limestone, with occasional isolated microbial buildups; c) The Carcará North/Itaipava Sag-Rift Limestone Play which is a light-oil trend that includes the Carcará discovery in BMS-8, with hundreds of square kilometers of closures at the base salt and relief reaching 350 to 400 meters. In this trend, reservoir facies are expected to have excellent reservoir properties and are interpreted as very large microbial buildups, oriented along fault zones which are located at the edges of the previous rift horsts.

3D seismic interpretation of the pre-salt section in the BC-200, deep to ultra-deepwater area in the Campos Basin has allowed the delineation of several pre-salt plays: i) Structural Play in coquinas (Late Rift to Sag); ii) Stratigraphic/Combination Play in coquinas (Late Rift to Sag); iii) Microbial Build-up Play on rift shoulders (Sag microbialites) and; iv) Microbial Build-up Play on volcanic complexes, potentially large limestone units beneath the salt nucleated on top of large volcanic complexes in distal settings.
A Probabilistic Risk Analysis of Extreme Events Based on Discrete Event Simulation for FPSO Operations
Authors: Chandrasekaran S. , Carrico T.
Published: October 2015

In this paper, a Discrete Event Simulation (DES) model for FPSO operations over its field lifetime is presented as a design tool for probability based risk assessment on occurrence of extreme events such as green water, wave slamming etc. The model simulates the cascading effect of realistic combinations of FPSO loading conditions and its dependence on shuttle tanker operations.

An FPSO engineering project normally includes a model test campaign to identify probability of occurrence and consequences of extreme events, such as green water or wave slam for a limited number of governing sea state with the FPSO in a vulnerable laden condition. At this stage, the risk assessment is limited to the fact that the FPSO experiences a governing sea state at a specified laden condition. The DES model presented in this paper addresses ways to remove the overtly conservatism in this risk assessment.

The DES model aims to characterise the FPSO loading patterns between successive offloading cycles. The model includes delays in offloading cycle due to shuttle tanker arrival and readiness at FPSO, scheduled maintenance on the FPSO process systems, etc. The results from DES iterations help to quantify the occurrence probability for any specified loading pattern in the FPSO over its lifetime. Together with the metocean scatter diagram which defines number of occurrences for each sea state, a conditional probability of FPSO experiencing a loading condition at governing sea state is calculated. This conditional probability can be applied to unbiased risk assessment of extreme events occurring in a governing seastate when the FPSO is at a specified loading condition.
Prospective Drift and Rift Plays in Ceará Basin, Brazilian Equatorial Margin - The Awakening of a Giant?
Authors: Belopolsky A. , Garwood T. , Beckmann G. , Fish P. , Cheshire O. , Crabtree N. , Sanders M. , Gomez R. F. Ballesteros , Pfeffer A. Dominguez , Hourcade A. Garcia , Badajoz D. Martin
Published: October 2015

Exploration in the Ceará basin, on the south-western part of the Equatorial Margin of Brazil, commenced in the early 1970s. Several moderate size fields such as Xaréu, Curimã, Atum, and Espada fields, with URR volume of around 200 MM BOE, were discovered on the shelf and are producing to this day. Exploration in the deep water part of the basin has been sparse (only 5 wells in water depth greater than 1000 m to date) with some success but, most importantly, de-risked the working petroleum system. With significant part of the deep water acreage licensed to operators in the 11th bid round in 2013, the basin is now embarking on a new exciting phase of exploration.

Ceará basin sedimentary fill is divided into three mega-sequences: syn-rift, transitional and drift. The basin is blessed with world-class source rocks of Aptian to Turonian age developed within all three main megasequences.

The Transitional megasequence contains both the source rocks and the reservoirs. This play was tested by the Pecem discovery in 2012 by Petrobras on the flank of a large structural high. Reservoir quality and connectivity remain the main uncertainty for this play. Other plays include a structural play with reservoirs in the syn-rift sandstones (Mundaú formation), and the Upper Cretaceous turbidite slope channel/canyons. In addition, in the outboard blocks onlap wedge plays in the Transitional early lower part of the drift megasequence have been identified. These plays could be analogous to the successfully tested plays on the conjugate margin in West Africa.

Premier Oil plc (Premier) and partner CEPSA have won two exploration licenses (Blocks CE-M-717 and CE-M-665) in the 11th bid round and are now the dominant acreage holders in Ceará basin. The Premier JV has reprocessed two existing 3D surveys resulting in an improved definition of both the syn-rift and drift section and imaging of new prospects and leads. A multi-client 3D survey using broadband technology is planned for 2015 which is expected to result in a superior seismic image in time for impacting the exploration drilling programme in 2017.
Technology Qualification of Tendon Connectors for Deep and Ultra Deep Water Application
Authors: D'Angelo L. , Viteri M. , Bradberry R. , Grimont R.
Published: October 2015

When new technology is deployed, it is critical to have the confidence that it will perform safely and as reliably as designed. For many years, DNV GL has helped companies that develop new technologies to implement a systematic, risk based Technology Qualification process (DNV RP-A203, 2013) [1]. The objective of this process is to ensure that all identified risks are properly addressed and the system performs the duties for which it was designed to. The field example described in this paper is based on Moho Nord's TLP located offshore Africa at 1,050 meters of water depth.

Hutshinson, contracted by Hyundai Heavy Industries (HHI) and Total in 2013, supplied the complete scope of connectors for the project. The overall qualification process covered a solution to install a tension leg platform in deep water, which required the utilization of a tendon connector system. It consisted of a Tendon Top Connector (TTC), Tendon Bottom Connector (TBC) and Intermediate Tendon Coupling (ITC). The focus of this paper will be the TBC which connected the TLP tendons to the sea floor. Although Hutchinson has supplied this type of connection for many years, this was the first time it was used for TLP application.

This paper provides an overview of Hutchinson's TBC, and the main steps covered by DNV GL's Technology Qualification process, as well as the results obtained. The understanding of the novel elements of this technology was obtained through a system to component assessment.

The execution of the TBC Technology Qualification Plan carried out activities addressing the failure modes defined for the novel components. All qualification activities were documented, and the data generated collected to ensure its traceability and to determine the performance margin for each failure mode. The performance assessment was carried out to ultimately compare the available qualification evidence against the boundary conditions established in the technology qualification basis, confirming that the technology had met or exceeded all of the requirements. Once the TQ process was completed, the equipment was considered as fully qualified within the intended application.
Monitoring and Optimizing a Brown Offshore Oilfield with an Integrated Asset Modeling Study
Authors: Garcia Ruiz F. , Ponce G. , Silva M. C. C. , Sauve R. , Rojas Mora J. A.
Published: October 2015

Producing oilfields are an excellent target for production re-development plan and optimization projects. All the wells were drilled and producing/injecting, fluid samples and ratios are known, artificial lift methods are usually in place, networks were installed, facilities were dimensioned and historical data is available.

This detailed information can be used to feed and calibrate advanced reservoir and network models which can be coupled in an integrate asset modeling platform. Coupling reservoir simulation models with surface networks permits each discipline, reservoir and production, to focus on detailed representation of field information gathered and allows the constrains of each part of the system to be imposed simultaneously.

Therefore, integrated asset modeling generates representative field production forecast and the opportunity to quantify many improvement scenarios options. These options are not limited but include modify gas-lift allocations, surface back-pressures and increase facilities capabilities.

This paper describes the methodology applied to the development of an integrated asset modeling study for a brown offshore oilfield in Brazil and the technical challenges faced. The project conducted included six reservoir models coupled to oil production, water injection and gas-lift distribution networks in order to evaluate the current production and future optimization scenarios.

The results obtained with this project demonstrated the impact of current water treatment facility in the field oil recovery and the potential gains associated with gas-lift optimization.
Analysis of Investment in Downstream Under the Production-Sharing Agreement - a Case Study: Libra, Brazil, 2014
Authors: Motta R. D. , de Araujo R. L.
Published: October 2015

This paper aims to evaluate the economic feasibility of a exploration and production of hydrocarbons project under the production sharing regime, specifically of the Libra field, Brazil, starting based upon some assumptions and considerations published before the auction. The discovery of pre-salt and the consequent changes in the Brazilian oil and gas industry with the introduction of production sharing agreements brought a new reality to the national market of hydrocarbons exploration and production. PETROBRAS was designated Operator of all blocks, with a minimum content of 30%. Previously, in the post-salt layer, Leasing Agreements were effective, and PETROBRAS, as every other company, could have 100% of a given block.

The high value of the signing bonus for the pre-salt areas and in particular to the area of Libra, subject of the first auction under the production sharing system, made it even more important to conduct a thorough and rigorous decision analysis applied to risky investments and taking into account the issue of risk tolerance.

This paper describes how to conduct investment and risk analyses through Monte Carlo Simulation and Decision Trees, and compares the outcomes of this study with the results of the auction in order to validate the methodology and determine optimum share versus risk tolerance.

The Decision Theory applied emulated the results observed for Libra: 40% PETROBRAS; 20% TOTAL and 20% Shell; and 10% each one of two Chinese Oil Companies. A comprehensive analysis is made with discussions about the result of the auction, how major oil companies positioned themselves, considering competitive strategy, technological and regulatory risks, as well as minimum governance requirements.
Novelties on Non-Emulsifiers for Completion Brines: Adapting Chemicals to Brazilian Oilfield Challenges
Authors: Poltronieri O. C. C. , Cunha P. J. , da Fonseca G. B.
Published: October 2015

During completion and workover operations, water-based, oil-based and acid-based fluids are injected into the well, entering formation pores and reaching oil reserves. Depending on the flow intensity and ambient conditions, these fluids may interact with oil to form viscous emulsions, causing several problems in the reservoir and ultimately a decline in oil production. Non-emulsifiers, when added to brines and acid solutions, are supposed to act as a barrier on the interface between the oil and the fluid, preventing emulsion formation and helping to maintain fluid’s properties and preserving the oil in the reservoir. Lately, Brazilian fields have faced challenges that resulted into the use of different fluids and brines and also different types of oil to be dealt with. Thus, the purpose of this work was to adapt some of techniques of emulsion breakage to develop novel non-emulsifiers formulations that cope with current technical and environmental requirements regarding emulsion prevention for oil exploration in Brazil. A series of studies has been conducted in order to better understand the effect of different parameters on the emulsion prevention of brines during completion operations. A Design of Experiments approach has been prepared in order to test different formulations (varying solvent and co-surfactant natures and content) in different scenarios: brines with different salts and oils with different °API. Once evaluated through adapted bottle tests, aqueous toxicity of most promising formulations has been evaluated. It has been found that solvent and surfactant types and concentrations have great effect on emulsion prevention. All those parameters were taken into account and enabled the design of an optimized formulation for the application. Further, another Design of Experiments approach has been prepared in order to understand how different scenarios impact on emulsion prevention: the novel formulation was tested against brines with different salts and oils with different °API. The effect of parameters such as oil density, BSW, brine pH, brine type and agitation could be assessed and a mechanism of action for the high performance non-emulsifier could be investigated.
An Integrated Power Solution for Enabling Large-Scale Subsea Processing: A Base Case for Subsea Standalone Variable Speed Drive in Brazil
Authors: Parente H. E.
Published: October 2015

There is a growing demand within the oil and gas industry for an integrated subsea power system in order to achieve the highest availability of power supply and power distribution subsea. For that reason, since 2010, a subsea power grid system has been under development by Siemens. The purpose of this system is to provide power to subsea consumers like pumps and compressors in deep and ultra-deep waters for long step-outs.

The subsea power supply and distribution system, including all its components, is designed and qualified to work at a water depth of 3000 meters, and up to more than 200 kilometres step-out distance. It will offer an integrated, reliable and cost-efficient subsea power solution for multiple consumers at seabed.

The development and qualification program is currently in its last stages. Testing of the individual components (subsea transformer, switchgear, variable-speed drive and communication/control system) will be followed by a complete system test. Overall, development and qualification program is expected to be completed in 2016, at which time the system will be ready for a full-scale subsea pilot project.

The power system must have standardized, flexible and configurable interfaces to have an optimal fit with the processing system. The integrity of the power system is governed by a dedicated power control and monitoring system which enables transparent and standardized communication with all the power modules. The Subsea Power Grid solution offers an infrastructure with standardized interfaces both on the topside / onshore power generation and to the subsea consumers – both for the power line and for the power control and communication line. This ensures flexible arrangements with the subsea field’s overall processing system without challenging the integrity of the power distribution.

One typical application for Subsea Power Grid solution would be a subsea standalone variable speed drive. The aim of this paper is to perform an overall analysis on how a subsea standalone variable speed drive can be integrated in a typical subsea pumping system without sacrificing the integrity of subsea variable speed drive sub-assemblies designed as part of subsea power grid solution.
Reserves Certification: The Actual Scenario of the Largest World Oil Producer Countries and Colombia
Authors: Câmara R. J. B. , Carvalho L. F. J. , Câmara G. A. B. , Rocha P. S. M. V.
Published: October 2015

Since the start of production in the pre-salt zone, Brazil became a large oil producer in the global scenario. Reserves certification is one of the most controversial topics in the oil industry. A reliable declaration of the oil reserves is essential to establish an appropriate condition that encourage the private sector, bring stability to society and get the government evolved. There are different manners for a company to certificate its oil reserves in the world; it depends on where the hydrocarbon is being produced. The reserves certification for the concessionaire companies in Brazil is performed by independent consultancy firms that execute certification under the ANP (National Agency of Petroleum, Gas and Biofuels) regulation. The regulation number 47 of September 3 of 2014 states the criteria for reserves certification in the country. This resolution is based on the Petroleum Resources Management System (PRMS), a document drafted by Society of Petroleum Engineers (SPE). Because of this diversity, this paper come up with a mapping of the existing systems for reserves certification in the fifteen largest world oil producers countries and Colombia, that is not a major producer but has a recent and solid regulation for reserves certification. This work is being developed to identify gaps and weakness in the current Brazilian regulatory rules aiming to avoid situations like the OGX company case. This company did not provide the same information to the regulatory agency and to the financial market. The instability in market reports to what happened to Royal Dutch/Shell Group in January 9 of 2004, even it is about a different technical situation. The methodology applied was based on the literature search about the subject and comparative analysis of the data. The research conduced to the main regulatory items in reserve certification for these countries: the existence of specific regulations for reserve certification, the productions limits for certification, the statement of reserves by the operator for the government agency and the recognition of the independent consultancy firms by the government agency. After analyzing the information obtained, it was realized that most of those countries do not have specific regulations for reserves certification. Some of these countries use the PRMS as a guideline and others simply use the numbers of reserves certified as political currency, disregarding any technical guidance. Finally, it was concluded the need for certain information about the numbers presented to the government and the financial market by the oil companies because the current system is shown unstable as evidenced by the research.
An Improvement of a Semi-Coupled Analysis for a Turret Moored FPSO in Deep Water
Authors: Xu Z. , Anderson K.
Published: October 2015

A fully-coupled method is deemed desirable for global response analyses of deep water floating structures. However, even with ever increasing computing power, the fully-coupled method is still time consuming, especially when a large number of different load cases need to be considered. In contrast, the computational cost is much lower for a semi-coupled method at the expense of analytical accuracy. The benefits of a fully-coupled method include taking into account the coupling effects between damping due to the slender structures and motions of the FPSO. Previous studies have indicated that the total damping can be significantly influenced by the mooring line damping. The semi-coupled method can be improved if this damping effect is properly modelled and included.

It is known from previous studies that mooring line damping can be significantly increased by wave-frequency (WF) motions. However, typically only harmonic WF motions were considered in these studies. In this paper, the effect of random WF motions on mooring line damping is investigated. It is found that, statistically, the effect of random WF motions on the mooring line damping can be represented by an equivalent harmonic WF motion. Based on this, the mooring line damping can be estimated and used in the semi-coupled analysis. A comparison of the semi-coupled method with a fully-coupled method is made by performing a global analysis of a turret moored FPSO under an extreme sea-state with a 100-year return period. It is shown that with the system damping properly estimated, the excursion results of the moored FPSO by the semi-coupled method are in very good agreement with those obtained by the use of the fully-coupled method.
Challenges in Offshore Natural Gas Processing
Authors: Bidart Antônio Marcos F. , de Melo Darley Carrijo , Passarelli Fábio Menezes , Nascimento Jailton Ferreira do , Silva Juliana Pereira , Andrade Leandro D. Sampaio , Pereira Leonardo dos Santos , de Rezende Tapajos Leticia , Grava Wilson Mantovani
Published: October 2015

The Brazilian offshore pre-salt cluster is one of the most important recent discoveries of hydrocarbon resources in the world. These fields normally present high CO2 content (more than 10%) and also high Gas Oil Ratio (GOR), thus might limit the oil production in the convention FPSOs project due to the capacity and complexity of gas processing plant. These conditions lead to application of alternative processes for gas treatment in offshore environment, such as molecular sieve for dehydration, fixed bed for H2S removal and CO2 removal membranes. Besides, due to high flow and high pressure drop involved in the treatment section, an increase in the number of equipment, such as compressors, heat exchangers and scrubbers are needed in order to reach high pressure values necessary for the CO2 reinjection into production zones for Enhanced Oil Recovery (EOR). proposes.

This objective will also contribute to increase complexity on the gas processing plant since it must deal with expected variations in GOR and CO2 content in natural gas during field lifetime. Petrobras and partners have been working, since 2008, with the objective to increase performance of existing processing and compression technologies and also supporting application of new ones (technological gaps) that can result in overall improvements in CAPEX and OPEX, such as: nano-sized zeolites for dehydration, new metal oxides for H2S removal with high capacity under influence of CO2, new material for membranes (ceramic and carbon tubes) and dense phase CO2 separation. The aim of the combined use of such iniatives is footprint and weight reduction, higher efficiency, less energy consumption with modular design. The purpose of this paper is to present the actual strategy for developing offshore gas process in Brazil, emphasizing the different technological gaps identified and the consequential road maps that are being pursued for the new units to be designed.
Hybrid Cellular Tendon Design for TLP in Ultra-Deep Water
Authors: Yu Jim , Wu Chunfa , Heidari Homayoun , Zhao Rex
Published: October 2015

Cellular tendon design expands the envelope of water depth and payload on TLPs and enables their use for ultra-deepwater developments as well as production hubs. Cellular tendon design was initially introduced to the industry at OTC Brazil 2013 where its design elements and features along with the corresponding feasibility assessments were presented. For the initial development of the Cellular Tendons, the fabrication and installation were based on onshore assembly and tow-out of the full-length tendons to the installation site. This design was developed mainly for installation sites where a nearby fabrication yard with open water access is available. This design is especially suitable for developments in areas with local content requirements, where a significant amount of investment can be made in local yards for fabrication and assembly of the tendons.

In order to accommodate current standard industry practice for fabrication and installation of the tendons, an alternative design to the full-length cellular tendon has been developed. This alternative design, named the Hybrid Cellular Tendon, employs the same tendon transportation and installation methods as for the conventional tendons. The hybrid cellular tendon can be fabricated in any of the existing tendon fabrication yards and can be installed by any of the current tendon installation vessels.

This paper presents design of the general system and component of the Hybrid Cellular Tendon. The paper demonstrates that performance of the Hybrid Cellular Tendon satisfies the ultra-deep water TLP requirements while providing advantages over that of the conventional tendons for TLPs as hubs with large payloads. The construction and installation of the Hybrid Cellular Tendon, which are well within the current industry's capability and practices, are discussed as part of the design in the paper. The Hybrid Cellular Tendon design further proves the feasibility of cellular tendons in enabling TLP applications in ultra-deep waters and /or with large payloads.