bluuebunny/crossref_metadata_2025 huggingface dataset:
Sesv Operations - Seven Years of Highly Reliable Solution
Authors: Lima Ubirajara , Dendena Marcio , Ribeiro Felipe , Falcometa Bernardo , Pereira Pedro
Published: October 2017

This paper presents the solution developed by Petrobras to support oilfield development in Campos and Santos (pre-salt) Basins. This system solution consists of a ship fitted with specialized topside and improved production string design, which together allow for quick XMT installation avoiding slickline or wireline operations, thus completely dismissing drill rigs after production or injection strings.
Flow Rate Measurement Using Test Separator and PDG Data Allows Individual and Commingled Production Zone Flow Rate History Calculation
Authors: Coimbra A , Puntel E.
Published: October 2017

Throughout the last years, considerable efforts have been made to increase the quality of reservoir monitoring, as to improve managing and predictability. The quality improvement in reservoir management achieved with the acquisition of bottomhole data through the use of permanent downhole gauges, PDGs, is so remarkable[1],[2] that today the requisite of PDG installation, mainly in wet x-mas tree completions, is nearly out of question[3] either for oil or gas producers or for water or gas injectors. Unfortunately, corresponding progress has not been attained with respect to the individualized flow measurement per well[4], or better yet, per completion interval in a single well, despite the recent advances in technology available to this effect[5],[6].

This paper presents results obtained through measurement of downhole flow rate and its correction to surface conditions from a well under commingled production zone. Earlier, Puntel [7] presented a first case in Portuguese considering one completion zone with a well that has, between the completion equipments, two PDG Mandrels, one of them measuring pressure between string and casing; the other measuring the pressure within the production string. These PDGs are located almost at the same vertical depth, but are related to different flow areas, so that the pressure difference recorded between them can also be used to calculate the total flow rate. Furthermore, another typical installation provides access to two or more completed zones, allowing individual annular pressure measurements. This completion scheme also provides ICV[8],[9] control, turning it possible to calculate individual zone contributions through almost the same methodology adopted to the one zone base case.

The flow rate is obtained by means of the Bernoulli equation[10], assuming measurement of differential pressure between two flow sections with different cross sectional areas or otherwise, the Darcy-Weisbach equation[11], referring to the pressure loss through long pipes with same cross sectional area. Thermodinamic functions as well as a simple calibration procedure provide volumetric flow rate correction from bottomhole to surface pressure and temperature conditions. Deviation from ideal behavior can indicate change in flow regime or, for instance, scale buildup[12] inside production tubing. Those techniques are feasible with high precision for single-phase liquid flow, a condition observed more frequently at bottomhole conditions. Field examples are provided to illustrate all presented cases.
First Application of Foamed Cement for Production Operation in Ultradeepwater Well: Case History
Authors: Antunes Tarcisio , Blanc Romulo , Fiorotti João , Oliveira Thais , Perez Miguel Vicente
Published: October 2017

An oil field located in the northern Campos basin has been producing since 1995. It is located in water depths ranging from 1500 to 2100 m and presents hydrocarbon accumulation in sandstone formations comprised of ten units. While conducting infield drilling, depleted zones with severe lost circulation issues were expected. Cementing operations in such conditions can be challenging and require special attention to cementing the drillstring and completely achieving zonal isolation objectives. During preplanning, foamed cement was considered based on its ability to mitigate formation compaction caused by formation depletion, the capability to fill lost-circulation voids compared to nonfoamed slurries, its excellent displacement properties, and good cement bond results, making it an excellent solution for this challenging scenario.

This paper presents a case history where foamed cement was used for a production casing in an ultradeepwater well in Brazil. The 12 1/4-in. production section was drilled to total depth (TD) using managed pressure drilling (MPD) technology and synthetic-based mud (SBM) at a density of 8.7 lbm/gal + surface backpressure (SBP). The goals for the cementing operation were the same as for the other production wells:

Provide a 200-m casing-to-casing barrier Achieve an 830-m height of cement (HOC) and top of cement (TOC) at 2900 m Evaluate the cement sheath using a bond log Provide complete zonal isolation across the reservoir Displace the drilling fluid across the annulus and place a competent cement slurry Provide hydraulic isolation between future fracturing stages Prevent isolating the perforation at 2710 m [annular pressure buildup (APB) mitigation]

The cementing challenges were significant and required the use of lightweight slurry to remain within the operational pressure window. Cementing best practices were closely followed, helping ensure a good bond was obtained under these conditions. Finally, the post-job cement bond log showed excellent bonding to the formation and pipe, which meant competent zonal isolation and wellbore were delivered for production.
An Integrated Approach in a Integrity Service Assists in Improving Zonal Isolation in Production Section
Authors: Martinez F. , Cardoso O. F. , Oyatomari C. , Moretti F. , Gomez J. M. , Ramirez F.
Published: October 2017

A multidisciplinary well integrity evaluation was performed in Latin America with the objective to improve zonal isolation issues caused by a channel that formed after cement placement between different formations in the production section of the well. The differential pressure between a high-pressure water zone and heavily depleted reservoir was observed to be the main driver behind this issue.

A well integrity service enabled analyzing a large amount of historical data from wells drilled between 2015 and 2016 in a timely fashion. This analysis accounted for a cross-verification of drilling practices, openhole logs, petrophysical evaluations, cement placement, and log evaluations between the wells, which led to formulation of two hypotheses concerning the conditions that are responsible for a post-placement channel:Differential pressure between water zone (high pressure) and zone of interest (low pressure) was higher than in those cases where crossflow did not happen.The depleted zone of interest presented higher mobility conditions, which could contribute to making the scenario more prone to crossflow due to pressure leakoff in the sandstone.

Based on these observations and drilling risk analysis, the drilling and completion programs on the subsequent well were adjusted. One of the decisions was to stop drilling before getting into the high-pressure water zone in the production interval. Another one was to optimize the cement placed in front of the high-permeability zone of interest, using high-tier technology with the objective of minimizing the cement-to-formation interactions and achieving enhanced properties.

In the case history, a well drilled with the new drilling program combined with improved cement properties showed adequate isolation across all target formations confirming the success of the well integrity service. Achieving zonal isolation from the beginning allowed the operator to move forward with drilling and completion programs, avoiding nonproductive time and costs that could reach USD 500,000 in remedial operations.

Achieving proper zonal isolation to assure the well integrity requires interaction between the multiple disciplines working in the well construction. By taking the holistic approach provided in the well integrity evaluation service, it was possible increase the level of assurance on cement evaluation interpretation and recognize the main contributing factors for formation crossflow. Mostly important, it provided a new insight, allowing the operator to make better decisions and, together with the service company, define the solution for properly isolating the formations in the production section without the need of remedial operations.
Subsea Fiber Wet-Mate Connectors: Achieving the Balance between Consistent Optical Performance, Product Cost and Compact Size
Authors: Saxton Elaine , Parente Helyson
Published: October 2017

Fiber connectors have been used in the Subsea Oil & Gas industry for some years. As the hunger for data grows, long step outs become more common and fiber communications in other industries becomes standard, the use of fiber in subsea Oil & Gas fields is set to increase. Whilst the optical loss along the fiber itself is low and the data-collection possibilities are high, these applications, and others besides, will only be fully realised if wet-mate fiber connectors can consistently achieve high optical performance.

A fiber connection is a physical face-to-face alignment of two fiber cores which are typically 9microns (9 thousandths of a millimetre) in diameter. A tiny misalignment, stand-off or particle of contamination at the 9micron connection point could cause an unwanted optical loss. Therefore in order to achieve the required optical specifications, the optical alignment must be extremely precise and the connection must be very clean.

Achieving both of these essential criteria within a wet-mateable fiber connector is particularly challenging. The necessary pressure compensation adds to the size and complexity of the design. Not only do industry specifications require excellent optical performance but the subsea structures housing wet-mate connectors are limited for space, and product cost effectiveness in a competitive market is increasingly important.

Siemens Subsea will demonstrate how the combination of proven subsea connector knowledge, together with a compact & innovative design, modular approach and an emphasis on cleanliness in assembly has been providing consistent and excellent results. The conclusion will provide results and evidence from a thorough Qualification programme which exceeds current industry requirements.
Optimizing Production of Santos Basin Pre-Salt Fields through Sound Reservoir Management Practices
Authors: Pizarro Jorge Oscar de S. , Poli Renato Espirito B. , Rosa Marcelo Becher , Silva Victor Costa da , Branco Celso Cesar M. , Cunha Bruno Miranda , Doria Maria Assunção F. S. , Alles Noé , Batello Daniel , Pinto Antonio C. C.
Published: October 2017

Since the beginning of the Santos basin pre-salt commercial production, in December 2010, more than 1 billion barrels of high quality oil have been extracted from these ultra-deep water carbonate reservoirs. To enable and accelerate production, Petrobras and its partners applied advanced and innovative technologies in various areas of engineering. This paper focuses on the reservoir strategies conceived during the design phase of the Lula and Sapinhoá development projects and their application in these fields.

The authors highlight practices and processes whose extensive use, in this type of scenario, were not standard. Among these, the dynamic characterization of the reservoirs by the use of long-term tests coupled with remote monitoring of pressure; water and gas production control by alternating injected fluids; intensive use of intelligent completion; convertible wells to accelerate production growth (ramp-up); CO2 injection from the start of production; rock-fluid interaction tests; optimization of well stimulation and many others.

Knowledge acquired during the first seven years of commercial production and the actions implemented to manage the reservoirs reflect on the production plateau extension and the final length of their expected productive life. The collection and analysis of static and dynamic data proved to be valuable to reduce uncertainties and support further development decisions. Integrated effort contributed to risk mitigation, production maintenance and increased forecasted final recovery.

The results obtained emphasize the importance of an effective reservoir management approach to maximize production and recovery. Concepts adopted are clarified through practical examples showing the advantages and gains from their implementation. The final message is that safe and viable operation of ultra-deep offshore fields benefits from additional investments in acquiring specific reservoir data. Their integrated analysis using advanced and up-to-date techniques is considered essential to maintain and improve asset values.
Unitization Involving Non Contracted Area: Comparison Between Contractual Models
Authors: Da Silva C. V. , Bonolo D. D.
Published: October 2017

In accordance with the regulations in force with respect to individualization of production (unitization), the Brazilian Government does not make any disbursement to bear its share of the investments and operating costs related to the production development of a shared reservoir. Accordingly, the amount must be paid by the other parties and discounted from the volume to which the Brazilian Government will be entitled according to its working interest determined on Production Individualization Agreement (AIP). Therefore, the Brazilian Government isn't has any business risk.

Representatives of private companies operating in Brazil refer to this situation as "the fourth regime", in reference to the three different exploration and production contracts in the country: Concession Contract, Onerous Assignment Contract and Production Sharing Contract. In this sense, the objective of this study is to compare the devices contained in the Brazilian legislation of the petroleum industry, regarding the individualization of the production of deposits, with the characteristics of the most common models of risk service contracts, according of the literature, and with production sharing contracts. As a result, it is hoped to contribute to the academic understanding of the subject by legislators, regulators and negotiators, representatives of the Brazilian Government and the private sector, considering that the estimated oil production from deposits that are or will be involved in significant unitization processes with the Brazilian Government.
DC/FO, A Lean and Powerful DC Subsea Control Infrastructure
Authors: Michel Ronan , Vareille Ghislaine , El Boussairi Hanae , Verhaege Thierry , Lemaitre Romuald , Audebert Rodolph
Published: October 2017

Subsea controls architectures have been traditionally based on large size project-specific umbilicals integrating hydraulics, data, power and chemicals. Tieback length and power consumption drive the dimensioning of umbilical cross-section.

The submarine telecom industry has an extensive track record of highly reliable, long reach, standardized solutions for DC powering and data transport.

An alternative cost effective subsea control infrastructure solution has been developed leveraging on the submarine telecom industry experience, based on reliable super-structural and standardized DC subsea power and optical fiber communication cable network, compatible with existing brown fields and future green fields subsea control systems, so-called DC/FO solution.

This innovative solution offers a number of advantages inspired from the telecom industry: Standardization – the same standard cross section can be used regardless of tie back length or power consumption demand; Reparability and Extendibility – The cable and its end terminations can be lifted to surface for repairs or extensions at sea with standardized jointing technology, simplifying the tie-back of new prospects and enabling phased development; Open platform – electrical power and communication interfaces can be connected to any SPS supplier equipment; Virtually unlimited reach within Oil and Gas fields – the system is dimensioned to serve the longest tie backs currently contemplated by the industry; Large power supply capability.

This solution is an enabler for new applications such as AUV recharge or E-Field sensing. On longer term, all-Electric trees can be powered through DC/FO solution, allowing further downsizing and cost reduction of legacy umbilical cross-section with the removal of hydraulic tubes.
Industrial Policy and Local Content: Brazil's Pre-Salt Area Case
Authors: Jesus F. D. , Silva J. F. , Roitman T.
Published: October 2017

The objective of this paper is to analyze the Local Content, as industrial policy in Brazil, especially in a low geological risk area as the pre-salt. The paper will regard its history, as well as its role, in the oil and gas supply chain, identifying the positive and negative aspects and discuss possible changes in the policy and its importance to the sector's growth recovery.

This paper promotes the discussion of the Brazilian Local Content policy as a form of industrial policy for the development of Oil & Gas sector, which is a very representative sector in terms of investment. This work involves the policy evaluation, identifying the reasons that have led to this choice in Brazil and comparing it to other examples around the world. The paper also analyses the possibility of using different types of industrial policies applied globally in Oil & Gas sector.

As the results of this study, it was identified that the Local Content policy is capable of promoting the sector's development and it can be positive for the players, especially in a low geological risk environment as Brazilian pre-salt. However, the policy must be adjusted so it allows the increase of competitiveness on a global scale, not only by the oil companies but also by the suppliers. A competitive national production is beneficial for the companies that operate in Brazil, which could reduce import of equipment, labor and services, making their production processes agiler. Regarding the suppliers, incentive policies are needed to promote their development and their establishment at a competitive level with other global companies. It was verified, however, that the policy needs adjustments, mainly with respect to focus definition of the sector's industrial policy. It is clearthat it is important to define key segments to be prioritized and to consider the Local Content policy as part of a wider industrial policy in Brazil.

The paper's original contribution is therefore to bring a wider theoretical framework to the current discussions taking place in Brazil about Local Content, considering the industrial policy theories. The discussion itself is relevant, in a moment of policy changes regarding the sector's development in Brazil and representativeness of the pre-salt in terms of impacts in the industry's production chain.
Plain Sailing? Observations of Cybersecurity and Network Health Problems in Control Systems at Sea
Authors: Csorba M. J. , Ramos de Carvalho C. , Boff S.
Published: October 2017

Threats to cybersecurity continue to increase in number and appear from unexpected new angles due to an increasing sophistication of cyber-attacks. A novel methodology is required not only for data protection but also to achieve safe and reliable operations at sea. The first step towards securing control systems is to make sure they are designed and operated per recognized international standards and recommendations, such as the ISO (International Organization for Standardization) 27000 series, the IEC (International Electrotechnical Commission) 62443 family of standards, the NIST (National Institute of Standards and Technology) framework, or the IADC (International Association of Drilling Contractors) cybersecurity guidelines. In addition, testing and probing these systems and their associated networks for possible vulnerabilities and robustness under high traffic loads are important to verify that the implementation of the design is safe, secure and carried out in accordance with the vendor’s or the system integrator’s documentation.

This paper provides tangible examples of findings from cybersecurity and network health tests performed on various vessels and installations, such as shuttle tankers, drilling rigs and FPSOs (floating production, storage and offloading), by DNV GL Marine Cybernetics Advisory. Typical pitfalls of on-board cybersecurity are discussed, such as inadequate protection mechanisms, installation failures and mismatches between documentation and installation, vulnerabilities in controllers, and insufficient network capacities.
Subsea Concept Alternatives for Brazilian Pre-Salt Fields
Authors: Buckley Kevin , Uehara Ricardo
Published: October 2017

The objective is to identify and compare subsea development concept alternatives for typical Brazilian pre-salt deep water applications, based on generic system functional requirements, SWOT analysis and comparative cost-benefit analysis of each alternative.

This is a fast track approach to perform screening assessment of multiple subsea concept alternatives. Key premises from project disciplines are set as givens to determine the subsea functional specifications. The process consists of identifying subsea layout architecture options capable to meet those functionalities and defining ways of application.

A SWOT analysis of each selected subsea concept is performed, together with a superficial cost-benefit analysis comparing those concepts.

In order to meet the premises and requirements (Subsurface / Wells / Topsides) for the characteristics of the Brazilian pre-salt deep water fields, the following subsea concepts were considered competitive:

Satellite configuration with flexible risers and flowlines

Daisy chain configuration with rigid risers and flowlines

Subsea cluster configuration with manifolds, rigid risers and flowlines and flexible jumpers

Hybrid solutions with rigid risers and flexible flowlines (with and without manifolds)

The SWOT analysis of each concept is based on pre-determined requirements / criteria and evaluated considering their TIC (Total Installed Cost) for the possible subsea systems. This essay discusses the preferred subsea concepts depending on application, criteria, premises and field characteristics.

Subsea scope represents typically between 25 – 40% of a project in a deep-water development. The relevance of this essay is to serve as a guidance of choice of potential subsea concepts for a project, in view of their benefits and their associated cost, where capital cost intensity and return on investment are key value drivers in a low oil price environment.
Multiphase Flow Measurement: Advantages and Brazilian Regulation
Authors: Saad Hugo C. , Ribeiro Luiz F. C. , Oliveira Moises
Published: October 2017

Multiphase measurement is still a complex process and involves an important analysis of the produced fluids in the oil industry. Intense research and technological developments in the field have been gaining important breakthroughs in the onshore sectors and especially in the offshore industry. Many companies have already developed meters that are able to read more accurately the multiphase flows and this way these developments have brought a significant number of advantages to measurement processes. The present work aims to list the important concepts that allow understanding the operation of the meters, the advantages that the multiphase measurement presents for the oil industry, including regulatory aspects for of this technology.
Real-Time Asset Optimisation - Integrity Management of Flexible Pipe Systems: Meeting the Challenge
Authors: Eckold Geoff , White Roger
Published: October 2017

Delivering better outcomes by embracing new ideas requires a different mind-set from what currently prevails in today's oil & gas industry. Impactful change can be best realised when organisations are emboldened to think and act differently.

Our industry has been seeking holistic and integrated solutions that maximise economic recovery of E&P operator assets. Although we are seeing improvements in certain areas, there is still an opportunity to enable faster technology introduction, apply more collaborative working and adopt innovative commercial models. By looking at the production system holistically, operators can increase production efficiency, maximise economic recovery and more effectively extend the life of their brownfield assets.

Flexible Pipe is an essential component within the overall production system, where its unique characteristics provide an enabling capability for the cost-effective exploitation of oil & gas resources using floating production systems.

However, the design and construction of such systems is complex rendering the application of conventional integrity management technology ineffective. Manufacturers of flexible pipe, including GE Oil & Gas, have risen to this challenge, meeting the needs of operators through the offer of a comprehensive package of products and services not only for the assurance of on-going integrity, but also to provide the essential information necessary to answer questions related to remnant life, changing operating conditions, service upsets and lifetime extension.

This paper describes a number of the technologies now available that have been specifically designed to cater for those degradation mechanisms that can impact the service life of flexible pipe, whilst accommodating the nuances of its design. Examples, include the use of embedded sensors incorporated within the pipe during manufacture, monitoring equipment that can be mounted externally to the pipe, and bespoke inspection solutions targeted at specific elements of the pipe construction. Particular focus is given on fibre optic and electrical sensor systems for the detection of outer sheath breaches, the most common form of damage seen in flexible pipe during service, and in the application of the MAPS® stress measurement technology. The latter can provide a unique insight into the integrity of the primary load bearing elements within the pipe design.
Closed-Loop Field Development Under Geological Uncertainties: Application in a Brazilian Benchmark Case
Authors: Hidalgo Davi M. , Emerick Alexandre A. , Couto Paulo , Alves José L. D.
Published: October 2017

The closed-loop field development (CLFD) under geological uncertainties is a general methodology that aims to optimize an objective function by successively adjust the development plan (DP) of an oil field as new information is made available by drilling and production of new wells. In this work, we propose a CLFD procedure and demonstrate its feasibility in the UNISIM-I benchmark case, based on the Namorado Field of the Brazilian Campos Basin. The CLFD cyclically uses the steps of history matching, selection of representative models and optimization of the DP in an ensemble of uncertain models, elaborated with a limited amount of initial information. For the first step, we use an ensemble-based data assimilation method to match production data and well logs obtained from a reference model that reproduces the behavior of the real reservoir. The representative models are selected based on their similarity considering dynamics and statics parameters of the reservoir. For the DP optimization, we use a genetic algorithm with nonlinear constrains over the selected models. The net present value (NPV) of the project is the objective function used to evaluate the methodology. The comparison between the NPV of the reference model using the DP generated by the methodology and an initial DP is used to measures the gains. The results show a 40.8% increase in NPV when applying the methodology compared to the initial DP. Moreover, the proposed CLFD procedure is able to improve decision making by systematically increasing the NPV of the set of uncertain models.
Intelligent Completions Used during Extended Well Test of Exploratory Wells in Brazil
Authors: Costa L. , Rodrigues D. , da Silva R. , Souza I. , Fernandes M. A.
Published: October 2017

This paper describes an extended well test (EWT) campaign using intelligent completions in a presalt reservoir. Brazil is recognized as a promising deepwater province because of large oil discoveries in the presalt polygon. One such discovery contains an estimated eight billion barrels of recoverable oil and is considered to be one of the largest fields recently identified. Several challenges and risks are associated with ensuring economic returns, such as properly constructing wells and extracting value from their lifecycles. Most presalt fields contain thick carbonate reservoirs with significant variations in vertical permeability and unknown behavior affecting long-term production. Most of those uncertainties can be reduced using extended well testing; however, the solution implemented uses multizone completions to perform EWT, providing a new level of reservoir understanding.

To better understand reservoir behavior during production, several options were analyzed for the first EWT to help minimize uncertainties concerning the extensive pay zone. Drilling wells provides valuable rock and formation knowledge; however, this information is not sufficient to simulate formation flow behavior during the field lifecycle and reduce production uncertainties. In addition, current oil market conditions imposed another challenge to maximize output during EWT, impacting some well designs and the campaign strategy. A triple-zone intelligent completion was envisioned as the optimum solution to be applied for properly understanding how each interval would behave under production or injection.

EWT was performed on two producers and one injector. Based on project requirements, gas and water had to be reinjected into the reservoir. Additionally, using two producers allowed the operator to maximize oil output while performing the EWT with production details from each zone rather than the entire well. Both producers were completed with dual-zone intelligent completions systems because of technical limitations, while the injector was completed as planned with three zones.

Proper planning, preparation, and experience from other projects contributed to the campaign success in such a challenging exploratory completion. During preparation, several evaluations and studies were performed to help ensure the proper technology was selected and the system could withstand the extremely high flow rates with high scaling potential expected along with other flow assurance concerns.

A future commissioning campaign in this field should allow further evaluation of the applicability of this concept to other fields, which is promising for reservoir evaluation studies.
Predicting and Detecting Equipment Malfunctions Using Machine Learning
Authors: Bangert Patrick
Published: October 2017

Condition Monitoring usually analyzes each measurement separately using static limit information. This results in false alarms and unhealthy conditions that are not alarmed. Using machine learning techniques, the big data gathered around large equipment or an entire plant can be analyzed as a single coherent whole to draw conclusions about its current state of health. First, a mathematical model of the relevant measurement is created using the other measurements available. This model represents the equipment or plant as a unit when it is operating as it should. Second, this expected value is compared to the measured value. If they agree, the current state is healthy. If they do not, an alarm is released and a maintenance activity must follow. This method is seen to be far more successful than standard condition monitoring thus preventing false alarms and always alarming unhealthy states.
Pre-Lay of Flexible Risers in Lazy Wave Configuration in Pre-Salt Projects: Overcoming Technical Challenges and Enabling Installation
Authors: Laquini S. , Fernandes P. Tavares , da Costa B. P. M. , Delalibera C. A. Armani , Moura P. H. S. , Gonçalves F. F. , Costa C. H. O. , Oliveira J. G. , Pereira M. C. , de Oliveira R. Caldeira
Published: October 2017

This paper presents the technical solutions assessment and details of the first implementation of the pre-laying procedure of flexible lazy wave risers, including buoyancy modules, before FPU arrival, on a Pre-Salt scenario.

Flexible risers are easily handled due to the small bending radius allowed during installation phase. Despite of that, the water depth and differential pressure in Pre-Salt scenario result in several customized flexible pipe structures, which makes pre-lay much more complex. Other limitations regarding monitoring system, recovery strategy, hibernation conditions, commissioning, buoyancy modules design water depth and intention of pre-laying several risers also turn installation limitations in evidence.

To overcome all these challenges, a hard work together with flexible riser suppliers and installer specialists had to be done to find a feasible way for pre-laying. The results obtained with assessment studies and first installations were crucial to mapping the risks and benefits associated to the pre-laying of flexible risers. A large part of the riser installation time is consumed by the required time to assemble the buoyancy modules on pipe. Thus, pre-laying strategy optimizes major milestones for offshore installation, anticipating first oil production, increasing the ramp up and mitigating the schedule risks due to decoupling of the arrival of FPU from the risers installation.

The early engagement and planning of operations were key factors to achieve benefits of this kind of installation. This engagement and discussions together among operator, suppliers and installers helped a lot to mitigate risks. The achieved maturity inspires confidence for the development of new similar operations. Relevant steps were detected in the pre-laying and recovery operations sequence, which may affect the layout design during the development planning, in order to optimize the operation.
Automatic Verification of Instrumentation Lessons Learned in New FPSO Projects by Using Constructability-Based Queries Applied to CAE Computer Aided Engineering Tools Databases
Authors: Torres M. S. , dos Santos B. P. , Diniz F. C. , Cintra P. V.
Published: October 2017

During development of FPSO projects for Brazilian pre-salt exploration, some cases regarding instrumentation requirements and specification checks in detailed design were analyzed due to its complexity and deep influence in platform safety and operability. Those cases were identified in constructability reviews and, applying Computer Aided Engineering tools, queries were developed to detect those issues in order to identify and solve inconsistencies between several involved disciplines in detailed design prior to procurement, construction and commissioning phases.

According to AACE International "Constructability is the integration of construction expertise into all phases of the project to benefit cost, schedule, quality, and overall project objectives. The successful use of construction knowledge and expertise increases the probability of project success."

Instrumentation team detected, in Constructability reviews, some issues with huge impact in procurement, construction and commissioning phases, if not properly solved. Engineering design automation team were then involved to develop a set of queries to detect those cases and obtain proper data, from design database, which was then used to determine detail design consistency level and take corrective measures.

Three queries were developed to be applied over CAE tools databases for special cases in verification of instrumentation requirements.

Constructability value improving practices combined with CAE tools were the key factor for success in detecting and preventing inconsistencies concerning instrumentation specifications. Constructability is the systematic method that integrates, from the initial stages of the project, knowledge and experience in construction and assembly in all phases to enhance competitiveness and ensure predictability of proposed results.

Considering the amount of documents and interfaces existing in megaprojects, automated verification saves time and resources compared to conventional methods.
A Step Change in Safety and Quality for ESP Deployment in the North Sea
Authors: Pastre L. , Barclay W. , Elrick D. , Kriptanto A.
Published: October 2017

The oil industry is going through a transformation in which reducing costs and increasing rig efficiency became paramount. In spite of this changing period, safety is, and must remain, the main concern for every offshore installation. In order to achieve a step change in safety during offshore ESP deployment in the North Sea, procedures and standard working instructions were reviewed and opportunities for improvements were identified. Innovative tools including a new cable spooling system and special subs were developed to increase safety and address operator concerns during ESP assembly. Special attention was also paid to the service quality and efficiency of the ESP offshore installation. The toolstore used during ESP completion was redesigned using lean and 5S techniques to optimize installation time, and a high efficiency tool was introduced to install cable protectors, considerably reducing ESP installation time. In order to monitor the changes and continue improving, a recording system was introduced and every offshore installation is recorded and used for assessment and training. The objective of this paper is to describe novel ideas developed in the North Sea that created a new level of safety and quality during ESP deployment. The improvements described in the paper might inspire other initiatives to increase quality and safety standards in the oil industry.
Subsea Demulsifier Injection to Reduce Emulsion Viscosity and Enhance Crude Oil Production
Authors: Khalil de Oliveira Márcia Cristina , Fulchignoni de Paiva Lívia , Meireles Francis Assis , Mendes Rafael , Dias da Silva Plínio Martins , Gonçalves Machado Lucas
Published: October 2017

Water-in-oil (w/o) emulsions are formed during the simultaneous flow of oil and co-produced water through the well and production pipelines. The viscosity increment due to stable w/o emulsion formation may lead to important production losses as friction pressure drop increases. The emulsion viscosity is affected by a number of factors, such as water content, oil viscosity, temperature, droplet size and the presence of solids. Rheological evaluations using synthesized emulsions of different Brazilian crude oils at different water contents showed the viscosity of a w/o emulsion at 50% water cut is about 5 to 9 times that of the oil and about 6 to 90 times at 70% of water cut. The experimental works presented here shows that emulsion breaker treatment is a good alternative to reduce crude oil emulsion overall viscosity and, consequently, improve production. This paper investigates this effect in two wells from Campos Basin, offshore Brazil.

For these two wells, field implementation of subsea demulsifier treatment resulted in a 47% additional oil production uplift, an increase of 3,000 bbl/d for the Company. Besides, these subsea chemical injections also promoted flow stabilization which allowed the opening of the production choke, restrained due to slug flow limitations at the top side treatment unit.

Despite the good results, further investigation was conducted to understand differences in oil production increment from each well. Thus, new laboratory tests (bench and flow loop) and multiphase flow simulations were performed based on field data in order to evaluate the difference in demulsifiers performance considering the fluid and flow characteristics. The results have shown that higher oil production is observed in wells that produce stable emulsions above 30% water cut, flowing with Reynolds number lower than 105. The additional oil production obtained in the field and confirmed by multiphase flow simulations at steady-state and transient regimes occurred primarily by the reduction of the frictional pressure drop. Secondary effects included flow stabilization, which allowed the choke opening and the consequent top side pressure reduction.

As crude oil emulsions are formed in most all oil production systems in its lifetime, the emulsion breaker’s subsea injection implementation is a concealed production uplift opportunity. The novelty of this study is in the discussion of the ability to define a criterion to select chemicals and wells to improve crude oil production in offshore systems.
Benefits of Using an Electric Choke for Subsea Applications
Authors: Rubio A. , Zeid H. Abu , Meyer J. H.
Published: October 2017

An electric choke can be an essential component of a subsea system and could represent the next major leap in subsea innovation. This paper presents the added functionality that an electric choke can bring to a subsea system during production startups and shutdowns as well as how it can improve condition monitoring and downhole instrumentation protection.

The electric choke can be easily integrated to a hydraulic or electric control system. It is driven by a motor and does not require stepping, therefore enabling greater control and precision. A comparison is presented between typical operations of a field using a traditional hydraulic choke versus an electric choke. We will also look at some of the additional benefits an infinite number of positions can bring to the system for production and injection field operations.

Electrically actuated chokes provide several advantages during production startup and shutdown. An unlimited number of precise positionings means that wells can be brought onstream and shut down gradually to prevent formation damage.

For monitoring purposes, there is an improved response time in diagnostics and interpretation of measurements coming from the downhole valves, sensors, wellhead, and subsea instrumentation. This improved response and additional information, including actuator motor power consumption, actuator motor speed, and valve and choke position, enable better condition monitoring, and through predictive analytics, uptime can be optimized and interventions can be reduced.

In long-offset fields, electrically actuated chokes provide protection of downhole equipment, such as surface-controlled subsea safety valves (SCSSVs) and downhole screens. Electric subsea production control systems have been around since the late 1990s. Because of the recent economic climate, the industry is now looking for more effective ways to produce hydrocarbons, and removing hydraulics from the system seems to be a cost-effective and technically feasible solution. Electrically actuating chokes provides great benefits and opens the door for fully electric systems in the future.
Uncertainty Analysis in Well Test Interpretation - The Conservation Principles
Authors: Kubota L. K.
Published: October 2017

Traditionally, Pressure Transient Analysis (PTA) has been performed following a deterministic agenda. However, parameters used to quantify permeability and reservoir geometry might be plagued with uncertainty, unavailable or utterly unreliable. Given a set of uncertain rock and fluid data modeled as probability density functions (PDFs), this paper shows that by preserving two quantities in the log-log pressure-derivative domain, one can promptly build permeability and reservoir dimensions PDFs consistent with the well-test pressure history.
Diagnosis and management of root resorption in traumatized teeth: Report of two cases
Authors: Lima Thiago Farias Rocha , Neto Julio Vargas , Soares Adriana de Jesus
Published: October 2017

Internal resorption (IR) is a progressive process initiated within the pulp space with the loss of dentin. Although trauma and pulp inflammation/infection are the major contributory factors in the initiation of IR, all the etiologic factors and the pathogenesis have not yet been completely elucidated. Cervical external resorption is defined as a localized resorptive process that commences on the surface of the root below the epithelial attachment and the coronal aspect of the supporting alveolar process, namely, the zone of the connective tissue attachment. This report is presented two cases of root resorption (external cervical resorption and inflammatory IR) in traumatized teeth where cone beam computed tomography has been used as an important diagnostic tool. Treatment of external cervical resorption involved endodontics and periodontics. In case with inflammatory IR, only endodontic treatment was necessary. The postoperative course was uneventful and a stable clinical outcome was obtained.
Changes in student evaluations of a medical ethics class 3 years later
Authors: Tonami Ken-ichi , Umemori Sachi , Nitta Hiroshi , Araki Kouji , Mataki Shiro
Published: October 2017

Aims: The present study investigated changes in the student evaluations of a medical ethics class after studying in dental school for an additional 3 years.Materials and Methods: A problem-based learning medical ethics class in which students discuss the “right to death with dignity” using video material as a trigger was offered to third-year students at the School of Dentistry. At the end of the class, each student submitted a report describing their own opinions of the ethical questions raised as well as their impression of the class. Three years later, the same students were surveyed regarding cognitive changes in class evaluations. The changes in class evaluations were statistically analyzed with reference to the contents of the initial report (P < 0.05). Results: Student evaluations of the class rose 3 years later. One reason for the evaluation rise was considered to be the growth in their reflection capacity during additional years of learning experience in the dental school. Students whose report demonstrated that they were engaged by the ethical dilemma tended to raise their evaluation of the class. On the other hand, students who mentioned the difficulty of the task or the shocking images in the video material in their initial report did not raise their evaluation later. Thus, students’ perception of the task or setting in the class appeared to have a continuing effect on their evaluation. Conclusion: The results confirmed that student evaluations of a class would change after additional years of learning experience.
Rapid Diagnostic Testing of Hospitalized Malawian Children Reveals Opportunities for Improved HIV Diagnosis and Treatment
Authors: Madaline Theresa F. , Hochman Sarah E. , Seydel Karl B. , Liomba Alice , Saidi Alex , Matebule Grace , Mowrey Wenzhu B. , O’Hare Bernadette , Milner Jr. Danny A. , Kim Kami
Published: October 2017

Recent World Health Organization (WHO) guidelines recommend antiretroviral therapy (ART) for all HIV-infected people; previously CD4+ T lymphocyte quantification (CD4 count) or clinical staging determined eligibility for children ≥ 5 years old in low- and middle-income countries. We examined positive predictive value (PPV) of a rapid diagnostic test (RDT) algorithm and ART eligibility for hospitalized children with newly diagnosed HIV infection. We enrolled 363 hospitalized Malawian children age 2 months to 16 years with two serial positive HIV RDT from 2013 to 2015. Children aged ≤ 18 months whose nucleic acid testing was negative or unavailable were later excluded from the analysis (N = 16). If RNA PCR was undetectable, human immunodeficiency virus (HIV) enzyme immunoassay (EIA) and western blot (WB) were performed. Those with negative or discordant EIA and WB were considered HIV negative and excluded from further analysis (N = 6). ART eligibility was assessed using age, CD4 count, and clinical HIV stage. Among 150 patients with HIV RNA PCR results, 15 had undetectable HIV RNA. Of those, EIA and WB were positive in nine patients and negative or discordant in six patients. PPV of serial RDT was 90% versus RNA PCR alone and 96% versus combined RNA PCR, EIA, and WB. Of all patients aged ≥ 5 years, 8.9% were ineligible for ART under previous WHO guidelines. Improved HIV testing algorithms are needed for accurate diagnosis of HIV infection in children as prevalence of pediatric HIV declines. Universal treatment will significantly increase the numbers of older children who qualify for ART.