bluuebunny/crossref_metadata_2025 huggingface dataset:
Fatores associados à realização de cesariana em hospitais brasileiros
Authors: Pádua Karla Simônia de , Osis Maria José Duarte , Faúndes Anibal , Barbosa Avelar Holanda , Moraes Filho Olímpio Barbosa
Published: February 2010

OBJETIVO: Avaliar a prevalência de cesariana em hospitais brasileiros. MÉTODOS: Estudo transversal com dados do Sistema Global de Dados para a Saúde Materna e Perinatal, da Organização Mundial da Saúde, para os estados de São Paulo, Pernambuco e Distrito Federal. Analisaram-se dados de 15.354 mulheres que tiveram parto entre setembro/2004 e março/2005, segundo características sociodemográficas e reprodutivas e do hospital. Foram realizadas análises bivariada - com cálculos de razões de prevalência e respectivos intervalos de confiança- e multivariada por regressão de Poisson. RESULTADOS: A razão de prevalência de cesarianas foi significativamente maior entre mulheres com maior idade, entre as casadas/unidas, e com maior índice de massa corporal. As condições apresentadas durante a gravidez ou parto, como diagnóstico de HIV da parturiente, maior peso e perímetro cefálico do recém-nascido, e maior número de consultas de pré-natal, se associaram à maior razão de prevalência de cesariana. Na análise de regressão mostraram associação direta com o desfecho: maior idade e escolaridade da parturiente; presença de hipertensão/eclâmpsia, doenças crônicas e de outras condições médicas; maior perímetro cefálico do recém-nascido, ser primípara, ter tido cesariana na última gravidez, e ter recebido analgesia peridural ou raquidiana durante o trabalho de parto. Embora a proporção de cesarianas tenha sido maior nos hospitais com índice de complexidade alto, a diferença não foi estatisticamente significante, assim como para as demais características dos hospitais. CONCLUSÕES: As condições da gravidez, do recém-nascido e as características sociodemográficas e reprodutivas da parturiente associaram-se independentemente à realização de cesariana. O índice de complexidade hospitalar não esteve associado, provavelmente pela homogeneidade da amostra de hospitais.
Physical activity during pregnancy and fetal outcomes: a case-control study
Authors: Takito Monica Yuri , Benício Maria Helena D'Aquino
Published: February 2010

OBJECTIVE: To investigate the relationship between physical activity during the second trimester pregnancy and low birth weight, preterm birth, and intrauterine growth restriction. METHODS: Case-control study including 273 low birth weight newborns and 546 controls carried out in the city of São Paulo, Southeastern Brazil, in 2005. Low birth weight cases were grouped into two subsamples: preterm birth (n=117) and intrauterine growth restriction (n=134), with their related controls. Information was collected by means of interviews with mothers shortly after birth and transcription of medical records. Data were analyzed using conditional multiple and hierarchical logistic regression. RESULTS: Light physical activity for over 7 hours per day was shown to be protective against low birth weight (adjusted OR=0.61; 95% CI 0.39-0.94) with a dose-response relationship (p-value for trend=0.026). A similar trend was found for intrauterine growth restriction (adjusted OR=0.51; 95% CI 0.26-0.97). Homemaking activities were associated as a protective factor for both low birth weight and preterm birth (p-value for trend=0.013 and 0.035, respectively). Leisure-time walking was found to be protective against preterm birth. CONCLUSIONS: Mild physical activity during the second trimester of pregnancy such as walking has an independent protective effect on low birth weight, preterm birth, and intrauterine growth restriction.
Atenção domiciliar como mudança do modelo tecnoassistencial
Authors: Silva Kênia Lara , Sena Roseni Rosângela de , Seixas Clarissa Terenzi , Feuerwerker Laura Camargo Macruz , Merhy Emerson Elias
Published: February 2010

OBJETIVO: Analisar práticas de atenção domiciliar de serviços ambulatoriais e hospitalares e sua constituição como rede substitutiva de cuidado em saúde. PROCEDIMENTOS METODOLÓGICOS: Estudo qualitativo que analisou, com base na metodologia de caso traçador, quatro serviços ambulatoriais de atenção domiciliar da Secretaria Municipal de Saúde e um serviço de um hospital filantrópico do município de Belo Horizonte, MG, entre 2005 e 2007. Foram realizadas entrevistas com gestores e equipes dos serviços de atenção domiciliar, análise de documentos e acompanhamento de casos com entrevistas a pacientes e cuidadores. A análise foi orientada pelas categorias analíticas integração da atenção domiciliar na rede de saúde e modelo tecnoassistencial. ANÁLISE DOS RESULTADOS: A implantação da atenção domiciliar foi precedida por decisão político-institucional tanto com orientação racionalizadora, buscando a diminuição de custos, quanto com vistas à reordenação tecnoassistencial das redes de cuidados. Essas duas orientações encontram-se em disputa e constituem dificuldades para conciliação dos interesses dos diversos atores envolvidos na rede e na criação de espaços compartilhados de gestão. Pôde-se identificar a inovação tecnológica e a autonomia das famílias na implementação dos projetos de cuidado. As equipes mostraram-se coesas, construindo no cotidiano do trabalho novas formas de integrar os diferentes olhares para transformação das práticas em saúde. Foram observados desafios na proposta de integrar os diferentes serviços de caráter substitutivo do cuidado ao limitar a capacidade da atenção domiciliar de mudar o modelo tecnoassistencial. CONCLUSÕES: A atenção domiciliar possui potencial para constituição de uma rede substitutiva ao produzir novos modos de cuidar que atravessam os projetos dos usuários, dos familiares, da rede social e dos trabalhadores da atenção domiciliar. A atenção domiciliar como modalidade substitutiva de atenção à saúde requer sustentabilidade política, conceitual e operacional, bem como reconhecimento dos novos arranjos e articulação das propostas em curso.
Indústria do conhecimento: uma poderosa engrenagem
Authors: Miguelote Vera Regina da Silva , Camargo Jr Kenneth Rochel de
Published: February 2010

O artigo aborda a articulação da indústria farmacêutica à indústria do conhecimento, por meio de poderosas estratégias de marketing. Com o objetivo de legitimar cientificamente seus produtos, a indústria interfere na produção de conhecimento médico. Configurando uma engrenagem de direcionamento de interesses econômicos, financia pesquisas na área de medicamentos, enviesa seus resultados e incentiva a produção e publicação de artigos científicos. Trata-se de uma engrenagem que ameaça importantes aspectos éticos: transforma o processo de legitimação científica em estratégia de marketing, compromete a credibilidade do processo de construção do conhecimento médico e incentiva distorções nos critérios de avaliação de qualidade dos artigos científicos.
Riserless Reelwell Drilling Method to Address Many Deepwater Drilling Challenges
Authors: Rajabi M. Mir , Nergaard A. I. , Hole O. , Vestavik O.M.
Published: February 2010

Drilling a well in deep oceans is a daunting task due to both downhole drilling hazards and excessive floating rig package. Traditionally many of these challenging wells are drilled with a low-pressure 21" marine drilling riser stretched from mudline to surface. A huge rig with high weight, space, and tensioning requirement is vital to handle this monster fluid conduit. Moreover, a reliable station keeping system is essential for the rig to keep it in a very tight operating radius to have drilling operations running uninterruptedly.

When we move to deeper waters and harsher environments, it becomes more difficult, and in many cases becomes even impossible to reach reservoir targets in such challenging environments. The problem of narrow formation pressure window also exists and adds up.

Reelwell Drilling Method has been proven by series of tests and theoretical studies to have the potential to alleviate the main drilling challenges by (1) elimination of the marine drilling riser to extend the capability of drilling in ultra deepwaters, (2) providing a closed-loop circulation system to make it possible for the industry to deploy Controlled Pressure Drilling (CPD) techniques and overcome many downhole pressure related challenges including narrow pressure window which is a common problem in deepwaters (Mir Rajabi 2009).
Closed-Loop Control for Decision-Making Applications in Remote Operations
Authors: Ornas Jens Ingvald
Published: February 2010

New technology and standards are affecting the way traditional control systems, used for operating Drilling Equipment, are prepared for interaction with Drilling by Wire systems or other systems that are capable of intervening directly in the drilling process.

It is well understood that there is a gap between available real-time data from a drilling operation and the cost effective utilizing of this data. Improvement will come from systems that are closing the loop, by analyzing parts of t he real-time information space – and directly intervene with the drilling equipment control, leading to better well placement and less wear on critical drilling components.

Remote and harsh environments, e.g. arctic regions, add motivation for increased inter-operability. Safe and reliable remote operation of drilling equipment will make it possible to reduce on-site manning, and thus reduce risk and cost involved in the drilling operation. Such systems will need a higher level of automation and will rely on a common, computer readable "understanding" of the drilling domain.

In order to achieve this – we need to find new methods to interact with both new and existing Drilling Control Systems – without going through complex, risky and long-winded integration phases.

AutoConRig is a RCN (Research Council of Norway) funded Joint Industrial Project that addresses this challenge – focusing on 3 main areas. Development of a standard for communicating with the Drilling Machines.Development of an agent framework, allowing for autonomous machine control.Creation and maintenance of drilling-related ontologies.

The AutoConRig project was started in 2008, and will continue until May 2012. AutoConRig is part of the larger project; Integrated Operations in the High North, which targets the implementation of a generation 2 digital infrastructural framework for integrated operations on the Norwegian continental shelf. Important parts of the current work, status and publicly available results from the AutoConRig project so far will be presented in the paper.
Weight Distribution in Reaming While Drilling BHAs
Authors: Meyer-Heye B. , Reckmann H. , Ostermeyer G.-P.
Published: February 2010

Reaming while drilling (RWD) in general means to simultaneously drill a pilot hole and open it up to the target diameter at the same time. This could be done using an eccentric reaming device or an expandable concentric underreamer; both are called reamer in the following. In RWD assemblies the weight applied to the BHA is distributed between the bit and reamer. To ensure optimized performance drilling, it’s necessary to know the distribution of weight as well as the distribution of torque in the BHA. For any calculation of drill string dynamics or tool durability the loads applied to the BHA are an essential input. The effort required to measure all loads while reaming is rather high so there is a need to calculate the weight and torque distribution from as few measurements as possible.

Based on aggressiveness and mechanical specific energy (MSE), an analytical method is shown to calculate the load distribution in RWD BHAs. Therefore a new approach to aggressiveness is introduced for calculation at the bit and reamer. By combination of aggressiveness and MSE, it can be shown how to derive weight and torque distributions in a RWD BHA. Effects of formation changes or different drilling diameters on the rate of penetration (ROP) can be calculated, as well as changes in the load distribution. To prevent the reamer from disruptive weight and torque, depth of cut control (DOCC) technology can be applied at the bit as described by Thomson (2008). How this technology affects the reamer, even if only applied at the bit will be shown as well. Based on data from a field test where weight and torque on bit and on reamer were measured simultaneously the accuracy/validity of the method is shown.
Advanced Modeling Technology: Optimizing Bit-Reamer Interaction Leads to Performance Step-Change in Hole Enlargement While Drilling
Authors: Partin Uyen , Compton Molly , Nelson Gail , Livingston Denise , Davis Patrick
Published: February 2010

The increasing necessity for hole enlargement while drilling (HEWD) technology has resulted in an essential need for engineers to fully understand the interaction between the drill bit and the hole opening tool. Inefficiency and damaging bit and bottom hole assembly (BHA) vibrations, caused by improper bit and reamer selection when drilling through interbedded formations and formation transitions, are a leading cause of inconsistent performance including excessive torque, low rate of penetration (ROP) and downhole tool failures (DTF). To mitigate vibrations, operators required a comprehensive analysis system/process that would allow them to model the complex BHA interaction in a virtual environment and quantitatively compare the performance of various design scenarios.

To solve the challenge, the drilling team utilized a comprehensive, 4-D finite element model that couples laboratory results with a sophisticated computer simulator that calculates the drilling system’s dynamic performance from the bit back to surface in a real-time domain. Unlike other modeling programs that assume the contact forces between the cutter and rock, this advanced model utilizes exact cutting structure details coupled with the laboratory-derived rock mechanics to accurately predict the behavior of the bit and reamer with the entire drill string and bottom hole assembly. The effects of each specific BHA component and variations in drilling parameters on vibrations, ROP, and directional tendency can then be quantitatively evaluated.
Drilling Deep in Deep Water: What It Takes to Drill Past 30,000 ft
Authors: Chatar Crispin , Israel Riaz , Cantrell Andre
Published: February 2010

In 1919 the world record for the deepest well was broken by the Hope natural gas company with a total depth (TD) of 7,579 ft. Although it took over 3 years to reach TD, only 325 days were spent actually drilling. Today in deepwater operations, the water depth alone can exceed this record, and operators have drilled past 30,000 ft in just 4 or 5 months. Technology and procedures have evolved extensively as operations that appeared impossible a decade ago are now considered routine. Today, operators are being pushed more than before, not just to explore deeper prospects, but also to get there efficiently. The future of the industry depends on it. Now there are new questions the industry is asking about deep water: What is different about drilling deep in deepwater operations? What does it actually take to drill the deepest wells in the world today? Currently, there are only a handful of personnel with the knowledge and experience to execute these wells. This paper will discuss the challenges of planning and drilling directional wells in excess of 30,000 ft true vertical depth (TVD) and will also look at lessons from some of the major deepwater Gulf of Mexico (GoM) operations that have successfully drilled wells beyond this mark and are continuing to push the envelope further. These wells have held, at one time or another, records for deepest wells drilled in many categories in recent years.
High Performance and Reliability for MPD Control System Ensured by Extensive Testing
Authors: John-morten Godhavn , Kjetil Arne Knudsen
Published: February 2010

This paper presents the control system, the preparations and some test results for a managed pressure drilling (MPD) operation at the Gullfaks oil field in Norway. The control system was developed with the objective of maintaining the bottom hole pressure (BHP) within a narrow pressure window and it was tested in two experimental set-ups; one test in a horizontal flow loop in Houston and a second test in a vertical test well in Dallas. Water was used as drilling fluid in both these tests. The paper also includes results from the offshore acceptance test in a cased well using oil based mud as drilling fluid. The main objectives of the on- and offshore testing were to qualify the MPD solution as much as possible and to save rig time offshore. The set of normal drilling operations performed in the preparation included connections, rate changes, pressure changes, start and stop of pumps, swab and surge, and drill string rotation changes. New functionality was developed to make a more flexible and robust system to handle contingencies. One is an automatic choke swapping system between two chokes for control if the automatic choke experiences malfunctioning or blocking. A second is a special solution developed to enable trapping of the BHP during unplanned shut downs of the main rig mud pump.
Hardware-In-the-Loop Simulations Used as a Cost Efficient Tool for Developing an Advanced Stick-Slip Prevention System
Authors: Kyllingstad Åge , Nessjøen Pål Jacob
Published: February 2010

Hardware-In-the-Loop (HIL) simulation is a technique where machine control software runs virtual machines, which are mathematical models emulating the physical machines. The technique has become increasingly popular in recent years, because of its ability to shorten product development time for complex dynamic systems, through quick and cost efficient testing over a wide range of conditions.

This paper focuses on the lessons learned from HIL simulation testing of an advanced and patent applied method for curing and preventing stick-slip oscillations in drilling. In this project the HIL simulations have provided several advantages, such as a high repeatability in test conditions, the ability to test under challenging conditions rarely occurring in the field, thus avoiding time consuming field tests. The HIL simulations have also proven to be an efficient tool for debugging the control software, because programming errors are discovered long before the commissioning and field test phases.

The HIL simulation of stick-slip oscillations uses an advanced dynamic model for the entire rotary system, including the top drive electronics, the motors, and the drillstring. The drillstring is modeled as a series of lumped inertia and torsional spring elements where the friction torque for each element is a non-linear function of the wellbore contact force and instant rotation speed. The lowest element also includes the bit torque as a function of weight on bit.

The first version of a stick-slip prevention system, which has been described in an earlier IADC/SPE paper, was HIL tested over a wide range of drillstring and well geometries. Simulations with very long strings (typically 5000 m or longer) revealed that higher mode stick-slip oscillations tend to appear when the normal stick-slip oscillations are cured. The second mode frequency is roughly three times the frequency of the fundamental mode so it falls outside the effective absorption band for the first version prevention software. However, after adding an inertia compensating term in the tuned speed controller, the stick-slip prevention software was able to prevent both the fundamental and the higher modes stick-slip oscillations at the same time. In summary, the HIL simulations improved the stick-slip prevention system so it is more robust, easier to operate and has improved performance. The HIL simulations also helped to find and eliminate code bugs.
Improved Drilling Performance Brings New Life to Colombia's Oldest Oil Field
Authors: Bonilla Pablo , Castillo Lizeth Alejandra
Published: February 2010

Oilfield assets are subject to a daily and perpetual decline, and as existing oil fields mature, recovering the remaining reserves is increasingly difficult. Billon dollar investments have to be made continually to offset the natural depletion and increase the production. The amount invested to overcome the depletion rate and increase the production is challenged by efficiency losses and rising expenses such as those generated by conservative drilling parameters, "train wrecks", hidden flat times and experience of the various service crew's personnel available in today's industry.

This paper will focus on the engineering aspect of wellbore construction that enhances the development of the oldest Colombian oilfield. Significant improvements have been achieved in drilling operations by focusing on the effective application of drilling engineering, lessons learned, Company's best practices, and the adoption of state-of-the-art rig technology, thus reducing the drilling cycle by improving flat-spot operations and drilling operations, allowing the continuity of the development of the La Cira-Infantas mature oil fields in Colombia. Before September 2008 four conventional rigs were being used to drill an average of 14 wells per month. In January 2009, due to the early success of the program, and the need to optimize the CAPEX under the then current market situation only two automated rigs remain in operation, drilling an average of 14 wells per month and reducing the well cost-per-foot in more than 18% while oil production has increased in the order of 42%, and the success of the drilling operations have led to switching from an intensive work over/well services campaign to a more efficient drilling campaign.
An Experimental and Numerical Approach to the Prediction of Collapse Resistance for Expandable Tubulars
Authors: Agata J. , Tsuru E. , Sawamura M. , Asahi H. , Tsugihara H.
Published: February 2010

Expandable tubular technology is an effective method for saving on the costs of well drilling and completion. There are many applications for casing repair and slim hole casing design. The most essential aspect of post-expansion expandable tubular (EXP-T) is collapse resistance, which is affected by not only the expanded pipe properties, but also the axial restraint caused by sticking pipe in wells.

This paper discusses the effect of expansion condition on the collapse and the prediction methods of the post-expansion collapse resistance by conventional formulas and numerical simulation. The test pipes for EXP-T were expanded at the various expansion ratios with/without axial restraint. Using the post-expansion pipes, full-scale collapse tests were performed. FEA (Finite Element Analysis) for pipe collapse considering the pipe geometries and the mechanical property was also carried out for predicting the collapse pressure of EXP-T after expansion. In addition, the accuracy of conventional formulas and FEM models for collapse prediction was inspected by comparing the collapse test results.

These results reveal potential to improve the collapse resistance of the pipe expanded under the axial restraint. Good agreements were found between the collapse test results and the predictions by FEA are drawn.
Automation of Mud-Pump Management: Application to Drilling Operations in the North Sea
Authors: Cayeux Eric , Daireaux Benoît , Dvergsnes Erik Wolden
Published: February 2010

Drilling in the North Sea is confronted with an ever more challenging pressure management issue due to narrow geo-pressure windows in depleted reservoirs. Further, the occurrence of pack-offs can cause serious damage to the formation and contribute to non-productive time. To address these problems, automation of mud pump management has been developed over the last four years to minimize the chance of fracturing the formation while starting the mud pumps or circulating. To account for abnormal flow restrictions in the annulus, automatic actions are also an integral part of the mud pump automation described in this paper.

Since the downhole conditions are continuously changing (depth, temperature, flow-rate, gel time, cuttings proportion, etc), the necessary safe guards to operate the mud pumps need to be updated constantly. Advanced transient temperature and hydraulic models are used to estimate, in real-time, the downhole situation. Based on the current context, evaluation of maximum pump rates and acceptable flow accelerations are performed and sent to the mud pump control system to be used as an envelope of protection. Furthermore, to assist the Driller during connections, the pump start-up procedure has been semi-automated in order to decrease connection time. Finally, an automatically triggered pump shutdown procedure is also available to minimize the consequences of a pack-off on formation fracturing.

A first version of the system has been tested during the drilling of one well in 2008 in the North Sea. Based on the initial experience, a revised version has been used during the drilling of three wells drilled on the Norwegian Continental Shelf in 2009. The feedback from the Drillers involved in the testing has been used to improve the user friendliness of the system. The automation of the mud pump management has been well accepted by the drilling crews. However, the testing has shown that additional instrumentation at the rig site is necessary before such automation can be rolled out safely.
Automation of Drawworks and Topdrive Management to Minimize Swab/Surge and Poor-Downhole-Condition Effects
Authors: Cayeux Eric , Daireaux Benoît , Dvergsnes Erik Wolden
Published: February 2010

Unwary axial and rotational movement of the drill-string can cause formation fracturing or fluid influx resulting in costly remedial actions. With increasingly complex wellbore geometries and narrow geo-pressure windows, it is not always obvious for the Driller to estimate the real manoeuvring limits of the drawworks and the topdrive, especially under poor downhole conditions. The solution presented in this paper uses continuously updated safe guards applied to the drilling control system to maintain a downhole pressure within the acceptable limits of the open hole formations. It also stops automatically the movement of the drill-string in case of abnormal hook loads or surface torques. Since automatic actions can be triggered in case of an unexpected situation, some standard procedures have been fully automated, including friction tests and back-reaming.

Numerical models are used to constantly calculate the maximum accelerations and velocities which can be applied to the drill-string in the current drilling conditions. The resulting envelope of protection is depending on many factors. Therefore, a proper evaluation of the downhole conditions is of paramount importance for the quality of the calculated safe guards. An automatic calibration of the physical models, based on surface measurements, is at the heart of the system. The calibrated mechanical models are used to determine the limits for abnormal surface torques or hook loads. It is therefore possible to automatically take actions in case of overpull, set-down weight or high torque.

In 2008, a preliminary version of the system has been tested during the drilling of a well in the North Sea. Even though the control algorithms did work well at that time, it has been noticed that in some circumstances the drilling control system would not be ready in time for fast changing drilling conditions. An improved version of the drawworks and topdrive automation system has been tested during the drilling of three North Sea wells in the spring of 2009. In this last version, the response time of the system has been optimal at all time. The Drillers involved in the testing of the system have found the system useful and user-friendly.
Drilling Efficiency and Rate of Penetration - Definitions, Influencing Factors, Relationships and Value
Authors: Mensa-Wilmot Graham , Harjadi Yoseph , Langdon Sheldon , Gagneaux Jay
Published: February 2010

Drilling efficiency must be improved, in order to drive down operational costs. This requirement must not be viewed in isolation, considering the vast number of activities that determine a drilling program's success. In most instances, discussions relating to drilling efficiency have centered on rate of penetration (ROP)1,2. As a result, ROP is either equated to drilling efficiency, or seen as the parameter that establishes drilling efficiency. These positions, in addition to being flawed, are highly inconsistent with field results. ROP must not be equated to drilling efficiency. Rather, ROP needs to be seen as one of several parameters that influence drilling efficiency.

The industry's most common performance quantifying metrics - cost per foot (CPF), feet per day (FPD), mechanical specific energy (MSE)3,4, etc - are strongly influenced by ROP. These relationships complicated earlier efforts that sought to establish the appropriate dependencies, between drilling efficiency and ROP. To drive down operational costs, while continuing to push drilling activities into harsher and more challenging environments, emphasis must clearly be placed on drilling efficiency. Thus, in order to achieve this goal, drilling efficiency and ROP must both be defined. In addition, the factors influencing ROP and drilling efficiency must be identified. Most importantly, drilling efficiency's different influencing factors5, which include but are not limited to ROP, must always be analyzed based on specific project objectives.

This paper, in addition to addressing the issues listed above, will also establish a clear distinction between drilling efficiency and ROP. In addition the contributions and impact of both ROP and drilling efficiency, as it relates to value creation will be discussed. The positions, to be presented and argued, will be supported with field and operational data.
Novel Applications of Drilling Simulators in Student Recruitment, Teaching and Research Programs
Authors: Ahmed R. M. , Smith J. R. , Bohorquez V. B. , Koederitz W. L.
Published: February 2010

Drilling simulators have been used extensively for teaching, especially well control, and for analyzing drilling operations, such as cementing. They also have been used to research the impact of drilling phenomena like drillstring dynamics. New approaches to develop and apply drilling simulation systems have been undertaken as a collaboration between industry and academia at two universities: Louisiana State University (LSU) and The University of Oklahoma (OU). The project involves the design and development of two different drilling simulators: a physical drilling model and a drilling simulation system. The simulators provide physical drilling demonstrations and/or hands-on simulation exercises that had previously been unavailable in an academic setting. Although the approaches are different, both are designed and developed for use in recruiting, teaching and retaining students as well as conducting simulation studies and supporting ongoing research efforts.

This paper describes the design and capabilities of the two drilling simulators and how their use is being integrated into the petroleum engineering educational programs at both universities. These novel drilling simulators are expected to have a positive impact on the recruitment and retention goals of these university degree programs. To date, their limited integration into course curriculum appears to have impacted student learning, as evidenced by improved test scores when compared to those prior to simulator implementation. Other conclusions regarding the impact of these early applications include improved student comprehension of new concepts. Plans for evaluating the broader impacts resulting from future uses of these simulation systems include observation, student performance assessments on exercises, lab reports, and tests as well as interviews of students, faculty, recruiters and involved industry personnel.
Multilateral Wells Reduce CAPEX of Offshore, subsea Development in Australia’s Northwest Shelf
Authors: Lawrence Brett , Zimmerman Mike , Cuthbert Andy , Fipke Steven
Published: February 2010

Multilateral technology reduces the number of production well slots required to effectively drain a reservoir, resulting in time and cost savings. Having fewer discrete subsea wellheads translates into a major reduction of investment capital in offshore environments. Reducing the cost of the subsea infrastructure is the primary benefit of multilateral well architecture, but additional benefits include reduced top-hole drilling costs, reduced project execution time, accelerated production, increased productivity index and fewer rig moves.

To take advantage of the benefits, the appropriate multilateral technology must be selected to avoid introducing additional risk and non-productive time (NPT) to the project. The multilateral junction system that meets the requirements of the wells on the Northwest Shelf of Australia has a proven track record in subsea installations. For this application, a TAML Level 5 system is required to provide hydraulic and mechanical isolation of the connected wellbores. Over the past 10 years, TAML Level 5 multilateral technology has been used extensively in the North Sea, whereas the Northwest Shelf of western Australia saw its inauguration in the southern hemisphere.

This paper discusses the lessons learned from nine horizontal TAML Level 5 dual-lateral wells drilled offshore in the Van Gogh field. The Van Gogh field provides an excellent example of a field that was developed from start to finish with multilateral technology as the enabler. The project was successfully completed in the second quarter of 2009 with a significantly lower capital investment than would have been required to develop the field with single horizontal wells.
Power of Design: Solid Expandable Installation Sets Multiple New Records in Deepshelf HP/HT Well
Authors: Nylund Jay , Flaming Sarah , Mitrushi Kristaq
Published: February 2010

With each installation of solid expandable tubulars, the opportunity exists to redefine the operating parameters of this enabling technology. A recent planned-in installation of a 6,935 ft (~2,115m) solid expandable openhole liner not only set a record as the longest expandable installation to-date, but also marked the first offshore-well application that combined swellable elastomer technology and solid expandable tubulars.

Operators have relied on solid expandable tubulars to mitigate and manage downhole wellbore problems for several years. However, the recent fundamental change in advanced drilling engineering philosophy is to plan solid expandable liners into the basis of design (BOD) to preserve hole size and reduce non-productive drilling time (NPT). For example, the most-recent record-setting solid expandable openhole liner (7-5/8 × 9-5/8 in.) was planned into the wellbore architecture of a previously drilled well to help explore deeper high-pressure high-temperature (HP/HT) reservoirs approaching 24,000 ft (7,315m) TVD. The swellable elastomers used on the expandable system ensured the required zonal isolation for a successful leak-off test, thereby greatly reducing the possibility for costly cement squeeze operations.

This paper discusses how solid expandable liner systems have facilitated multiple exploration and development projects in the region to address drilling and completion challenges. This paper also describes how combined technologies enable a greater application realm and uses the record-setting case history to illustrate the value gained by planning and using solid expandable technology.
Nonproductive Time NPT Reduction Delivered Through Effective Failure Investigations
Authors: Hubbard Brad L. , Kadri Shabib J. , Crotinger Michael J. , Griffith James E. , van Oort Eric
Published: February 2010

Nonproductive time (NPT) caused by preventable tool and equipment failures in offshore drilling and completion operations typically accounts for 5% of well delivery time, but can reach as high as 30%[1]. This equates to millions of dollars per year that could have been spent on other well delivery opportunities. Mutual benefit exists for both operators and vendors to dedicate the time and effort necessary to consistently perform comprehensive investigations and develop effective solutions to mitigate risk of repeat failures. A one-sided or inadequately supported approach to failure response can lead to incomplete analyses and insufficient solutions that treat symptoms rather than root causes, thereby sustaining or creating reliability gaps and allowing further NPT to be incurred.

In recent years, Shell’s Gulf of Mexico (GOM) drilling operations formed a specialized, dedicated team to establish and facilitate an effective, sustainable approach to failure response. The team’s immediate goal was the reduction of NPT cost associated with drilling tool failures. Long term, the team’s objective was to promote a culture within both operator and vendor organizations for effective failure prevention and performance improvement. Via this team consistent representation, influence, and support is maintained during failure response activities. The team enforces vendor failure response expectations and ensures complete, unbiased analyses and solutions with appropriate local, regional and global communication within operator and vendor organizations, such that the chance of repeat failures anywhere in the industry is minimized.

Since inception, the team’s efforts have facilitated a significant reduction in NPT, which translates to yearly multi-million- dollar savings. Given its evident success, the scope of this initiative has been expanded within the Americas and also in global operations. This paper reviews the approach and process, clarifies the roles, responsibilities and accountabilities for both operator and suppliers, highlights the mutual benefits for operators and vendors, and illustrates the effectiveness of the approach through its very positive impact on operational NPT reduction.
Fully Automated Pipehandling System on a 6th Generation Drilling Vessel
Authors: Rohde Kjell , Berg Tore , Yost Tom , Aanesland Svein Ove , Kudsk Gregers
Published: February 2010

Drillfloor equipment controls and associated equipment on the latest generation of floating drilling vessels have evolved into a "system" of computer controlled machines that are currently operated by multiple operators each running these machines from a series of dedicated control stations. The latest drilling vessels utilize as many as three (3) operator stations to drill the well, trip the tubulars, or perform offline activities such as stand building. These stations all individually control their respective machines, but do require constant "multi-tasking" operations by their operators which results in inefficiency and operator fatigue.

A multi-machine control (MMC) system for automatic control of the hoisting, rotating, and pipehandling systems has been executed on a recently delivered 6th Generation Semi. The MMC allows full automatic control of these systems from ONE Operator using ONE joystick.

This paper will discuss the control system and machine hardware and software and how the development process has taken this technology from a "concept" to a working drilling and tripping machine that adds value, efficiency, and safety to what has previously been a multiple operator station deliverable.
Utilizing an Engineered Particle Drilling Fluid to Overcome Coal Drilling Challenges
Authors: Zeilinger Sabine , Dupriest Fred , Turton Ryan , Butler Hayden , Wang Hong (Max)
Published: February 2010

Borehole instability and stuck pipe while drilling coal can lead to significant non-productive time. This paper describes a drilling fluid developed to stabilize coals in a program that was previously unable to achieve all extended reach objectives. The fluid design principles are believed to apply broadly in stabilizing coals, fractured shale, and other cleated formations.

The rock mechanics that govern instability in coals is identical to shale. However, coal instability often does not respond to the same remediation used in shale, which is to simply raise the mud weight to reduce the compression hoop stress to below the strength of the rock. Despite using an optimum mud weight, hole breakout or borehole collapse may still occur when the coal cleats and natural fractures of the coal allow the drilling fluid filtrate to invade. This leads to a pressurization of the near- wellbore region and loss of the effectiveness of mud weight support for coal stability.

A fluid was developed based on the belief that the wellbore is stabilized with increased mud weight if the additional pressure acts specifically on the face of the borehole. This stabilization effect can be achieved by preventing pressure penetration into the near-wellbore region through coal cleats or natural fractures. The fluid design developed included bridging particles with a size distribution based on analysis of the coal cleat apertures, as well as filtration control material to effectively reduce the permeability of the bridge. Sealing alone does not provide stability and an analysis of the coal strength and in-situ stresses were conducted to select a mud weight that would stabilize the very weak coals.

The paper discusses the rock mechanics concepts, fluid design criteria for determining the allowed leakage rate when designing the bridging process, and the operational learnings from implementation. The use of the coal stabilization fluid and stability mud weight allowed the objectives to be achieved and contributed to record performance in this a narrow-margin drilling environment in Australia.
Well Delivery Process: A Proven Method to Improve Value and Performance While Reducing Costs
Authors: de Wardt John P.
Published: February 2010

Description

A Well Delivery Process defines a set of activities along a time line to plan, execute and close out a well. The most advanced versions of this process include tools and techniques that create robust plans including risk and uncertainty management, technical limit focus and stretch goals, probabilistic time and cost estimating, detailed scheduling, Drill / Complete the Well on Paper and similar group exercises. Stage gates are included that provide review points which are usually matched to a corporate Capital Value or Opportunity Realization Process. The most advanced form of the process incorporates best practices from Lean Manufacturing. The paper describes best practices in the development of a Well Delivery Process.

Application

The Well Delivery Process applies to all wells in a scalable format whereby a longer term, more detailed process is used for Exploration Wells and a simpler, shorter duration process for repeatable development wells. It covers work processes between departments, especially subsurface and drilling, and between the suppliers and the oil company, as well as between suppliers. An actively maintained Well Delivery Process provides the means to capture lessons learned and to retain knowledge within a company.

Results, Observations, Conclusions

In a West African offshore operation in a marginal field development with complex wells, the application of a Well Delivery Process resulted in best in class performance in an industry benchmark survey (Rushmore Review). This included a 77% reduction in non productive time. Added value was achieved through increasing the typical well productivity by more than 33%.

In the N Sea, a horizontal well drilled from a semi sub achieved an overall drill rate of 171 m / day versus a historic average of 80 m / day. Well cost was reduced by 30%.

A N Sea operator improved from 3rd quartile to 1st quartile performance while another improved overall drilling performance by more than 30%.

Reviews of drilling performance in two different regions demonstrated the correlation with poorer performance when there was insufficient lead time for proper planning according to the Well Delivery Process due to late and frequent drilling sequence changes.

Lessons learned are described including the correlation of performance with robust risk assessment

Recommendations on the key characteristics for a successful Well Delivery Process are described.

Significance of Subject Matter

A best practice and robust Well Delivery Process is essential for high cost drilling operations and challenging drilling environments whether exploration wells or infill drilling in depleted reservoirs to small hydrocarbon accumulations. This paper will provide an essential guide to Drilling Managers wishing to develop a Well Delivery Process.

The paper also introduces Business Process distinctions for different types of wells from project based exploration through Factory Drilling which impact the application of a Well Delivery Process.
Hybrid Bits Offer Distinct Advantages in Selected Roller Cone and PDC Bit Applications
Authors: Pessier Rolf , Damschen Michael
Published: February 2010

Early concepts of hybrid drill bits go back to the 1930's but the development of a viable drilling tool has only become feasible with the recent advances in polycrystalline diamond compact (PDC) cutter technology. This paper describes a new generation of hybrid bits that are based on proven PDC bit designs with rolling cutters on the periphery of the bit. Laboratory and field results will be presented that compare the performance of hybrid bits with that of conventional PDC and roller cone bits. A hybrid bit can drill shale and other plastically behaving formations two to four times faster than a roller cone bit by being more aggressive and efficient. The penetration rate of a hybrid bit responds linearly to RPM unlike roller cone bits, which have an exponential response with an exponent of less than one. In other words, the hybrid bit will drill significantly faster in motor applications. Another benefit is the effect of the rolling cutters on bit dynamics. Compared to conventional PDC bits, torsional oscillations are as much as 50% lower; stick/slip is reduced at low revolutions per minute (RPM), and whirl at high RPM. This gives the hybrid bit a wider operating window and greatly improves toolface control in directional drilling. The hybrid drill bit is a highly application-specific drill bit aimed at 1) traditional roller cone applications that are rate-of-penetration (ROP) limited, 2) large diameter PDC and roller cone bit applications that are torque or weight-on-bit (WOB) limited, 3) highly interbedded formations where high torque fluctuations can cause premature failures and limit the mean operating torque, and 4) motor and/or directional applications where a higher rate of penetration and better build rates and toolface control are desired.