bluuebunny/crossref_metadata_2025 huggingface dataset:
DC Brushless Motor Control Design and Preliminary Testing for Independent 4-Wheel Drive Rev-11 Robotic Platform
Authors: Saputra Roni Permana , Ardiansyah Rizqi Andry , Mirdanies Midriem , Santoso Arif , Nugraha Aditya Sukma , Muqorobin Anwar , Saputra Hendri Maja , Susanti Vita , Rijanto Estiko
Published: October 2013

This paper discusses the design of control system for brushless DC motor using microcontroller ATMega 16 that will be applied to an independent 4-wheel drive Mobile Robot LIPI version 2 (REV-11). The control system consists of two parts which are brushless DC motor control module and supervisory control module that coordinates the desired command to the motor control module. To control the REV-11 platform, supervisory control transmit the reference data of speed and direction of motor to control the speed and direction of each actuator on the platform REV-11. From the test results it is concluded that the designed control system work properly to coordinate and control the speed and direction of motion of the actuator motor REV-11 platform.
Modeling of Electric Field Around 100 MVA 150/20 kV Power Transformator using Charge Simulation Method
Authors: Rachman Noviadi Arief , Risdiyanto Agus , Ramdan Ade
Published: October 2013

Charge Simulation Method is one of the field theory that can be used as an approach to calculate the electromagnetic distribution on the electrical conductor. This paper discussed electric field modeling around power transformator by using Matlab to find the safety distance. The safe distance threshold of the electric field to human health refers to WHO and SNI was 5 kV/m. The specification of the power transformator was three phases, 150/20 kV, and 100 MVA. The basic concept is to change the distribution charge on the conductor or dielectric polarization charge with a set of discrete fictitious charge. The value of discrete fictitious charge was equivalent to the potential value of the conductor, and became a reference to calculate the electric field around the surface contour of the selected power transformator. The measurement distance was 5 meter on each side of the transformator surface. The results showed that the magnitude of the electric field at the front side was 5541 V/m, exceeding the safety limits.
Sammlung von Desideraten als Mittel des Bestandsaufbaus
Authors: Klauß Henning
Published: October 2013

Die Sammlung von Desideraten ist ein relevantes Instrument des Bestandsaufbaus. Bedingungen für diese Sammlung sind gute Inhalte und eine sachlich sinnvolle Struktur. Beide Bedingungen bedürfen der Pflege.
SERS-based detection of biomolecules
Authors: Cialla Dana , Pollok Sibyll , Steinbrücker Carolin , Weber Karina , Popp Jürgen
Published: October 2013

In order to detect biomolecules, different approaches using for instance biological, spectroscopic or imaging techniques are established. Due to the broad variety of these methods, this review is focused on surface enhanced Raman spectroscopy (SERS) as an analytical tool in biomolecule detection. Here, the molecular specificity of Raman spectroscopy is combined with metallic nanoparticles as sensor platform, which enhances the signal intensity by several orders of magnitude. Within this article, the characterization of diverse biomolecules by means of SERS is explained and moreover current application fields are presented. The SERS intensity and as a consequence thereof the reliable detection of the biomolecule of interest is effected by distance, orientation and affinity of the molecule towards the metal surface. Furthermore, the great capability of the SERS technique for cutting-edge applications like pathogen detection and cancer diagnosis is highlighted. We wish to motivate by this comprehensive and critical summary researchers from various scientific background to create their own ideas and schemes for a SERS-based detection and analysis of biomolecules.
Is folic acid supplementation to food benefit or risk for human health?
Authors: Bjelakovic Gordana , Stojanovic Ivana , Jevtovic-Stoimenov Tatjana , Bjelakovic Ljiljana , Kamenov Borisav , Pavlovic Dusica , Kocic Gordana , Sokolovic Dusan , Basic Jelena , Bjelakovic Goran B.
Published: October 2013

The need for sufficient quantities of folic acid for normal embryogenesis and fetal development is well known. Women of childbearing age must be sure to have an adequate intake of folic acid periconceptionally prior to and during pregnancy. Folate plays an essential role in the biosynthesis of RNA and DNA, phospholipid and neurostransmitters synthesis, using S-adenosylmethionine (SAM) as the primary methyl group donor. In some countries, the knowledge that folic acid is preventable for the reduction of the risk for neural tube defects (NTD) and in lowering the high amount of homocysteine (Hcy) led to the recommendation that all women capable of becoming pregnant should consume 400 µg of folic acid daily. Later, in 1998, folic acid fortification of all enriched cereal grain product flour was implemented in some countries. In addition to careful monitoring of adverse effects, the studies are warranted in order to determine the potentially positive and deleterious effects of folic acid fortification and supplementation on the human health or human diseases. To further understand the metabolic action of folates we asked ourselves the question: Is the intake of a sufficient amount of this vitamin a benefit or risk for human health?
Moving Beyond Themes
Authors: Lucas Kristen , D’Enbeau Suzy
Published: October 2013

Teaching novice qualitative researchers how to move beyond first-cycle themes is a challenging endeavor. In this essay, we articulate four harmful habits that tend to impede our success: moving too quickly, privileging product over process, providing cursory coverage of analytic technique and artistry, and overlooking the role of synthesis in qualitative research. As a step toward replacing harmful habits with more healthy ones, we offer a number of practical suggestions for reimagining the qualitative research methods curriculum.
Evidence for a role of sterol 27-hydroxylase in glucocorticoid metabolism in vivo
Authors: Vögeli Isabelle , Jung Hans H , Dick Bernhard , Erickson Sandra K , Escher Robert , Funder John W , Frey Felix J , Escher Geneviève
Published: October 2013

The intracellular availability of glucocorticoids is regulated by the enzymes 11β-hydroxysteroid dehydrogenase 1 (HSD11B1) and 11β-hydroxysteroid dehydrogenase 2 (HSD11B2). The activity of HSD11B1 is measured in the urine based on the (tetrahydrocortisol+5α-tetrahydrocortisol)/tetrahydrocortisone ((THF+5α-THF)/THE) ratio in humans and the (tetrahydrocorticosterone+5α-tetrahydrocorticosterone)/tetrahydrodehydrocorticosterone ((THB+5α-THB)/THA) ratio in mice. The cortisol/cortisone (F/E) ratio in humans and the corticosterone/11-dehydrocorticosterone (B/A) ratio in mice are markers of the activity of HSD11B2.In vitroagonist treatment of liver X receptor (LXR) down-regulates the activity of HSD11B1. Sterol 27-hydroxylase (CYP27A1) catalyses the first step in the alternative pathway of bile acid synthesis by hydroxylating cholesterol to 27-hydroxycholesterol (27-OHC). Since 27-OHC is a natural ligand for LXR, we hypothesised thatCYP27A1deficiency may up-regulate the activity of HSD11B1. In a patient with cerebrotendinous xanthomatosis carrying a loss-of-function mutation inCYP27A1, the plasma concentrations of 27-OHC were dramatically reduced (3.8 vs 90–140 ng/ml in healthy controls) and the urinary ratios of (THF+5α-THF)/THE and F/E were increased, demonstrating enhanced HSD11B1 and diminished HSD11B2 activities. Similarly, inCyp27a1knockout (KO) mice, the plasma concentrations of 27-OHC were undetectable (<1 vs 25–120 ng/ml inCyp27a1WT mice). The urinary ratio of (THB+5α-THB)/THA was fourfold and that of B/A was twofold higher in KO mice than in their WT littermates. The (THB+5α-THB)/THA ratio was also significantly increased in the plasma, liver and kidney of KO mice. In the liver of these mice, the increase in the concentrations of active glucocorticoids was due to increased liver weight as a consequence ofCyp27a1deficiency.In vitro, 27-OHC acts as an inhibitor of the activity of HSD11B1. Our studies suggest that the expression of CYP27A1 modulates the concentrations of active glucocorticoids in both humans and mice andin vitro.
Selenium: its antioxidant effects and issues in selenium supply
Authors: Molnár Jeannette
Published: October 2013

The author first summarizes briefly the antioxidant effects attributed to selenium. Literature data on the selenium supply in Hungary are reviewed in detail, also noting some important international reports. Hungarian soils are selenium deficient and this is reflected partly in selenium content of the plants, too. Selenium supplementation has been generally applied to most livestock since the 1980s in Hungary in order to prevent diseases associated with selenium deficiency. There are little data on the selenium content of Hungarian foodstuffs; therefore, selenium content of important foodstuffs available in the European Union is reviewed in detail. Data on selenium concentrations in human plasma or serum are scarce, and the results depend substantially on the analytical methods applied. In conclusion, Hungary is a country with marginal selenium deficiency, and this may play a role in the pathogenesis and poor treatment results of several diseases. Orv. Hetil., 154 (41), 1613–1619.
Impact on Thin Film Silicon Properties and Solar Cell Parameters of Texture Generated by LaserAnnealing and Chemical Etching of ZnO:Al
Authors: Boukhicha Rym , Johnson Erik , Daineka D. , Michel Antoine , Lerat J.F. , Emeraud Thierry , Roca i Cabarrocas Pere
Published: October 2013

The use of a laser annealing and chemical texturing process (dubbed the LaText process) on room-temperature sputtered ZnO:Al has been shown to generate unusually high haze properties, favorable for thin film silicon solar cells.This is due to the melting of the ZnO:Al layer by the XeCl laser, and the formation of crystalline domains onthe surface, for which the grains and grain boundaries are subsequently etched at different rates. The unusual surface morphology produced through this process can strongly impact the nature of the amorphous or microcrystalline silicon material deposited thereupon. In this paper, we report on results for amorphous silicon devices, for which the surface texture is seen to slightly impact thelight absorption in the material, but more interestingly, also the light-induced degradation of the cells.For co-deposited cells, devices deposited on surfaces with the characteristic "LaText" morphologyundergo a much lesser degradation. Furthermore, the decreased degree of degradation coincides with a notable shift in the Raman scattering peak. This provides a rapid diagnostic for testing multiple textures and deposition parameters.
Nano-Hydroxyapatite Coated Femoral Stem Implant by Electrophoretic Deposition
Authors: Zhang Heng , Krajewski Jay , Zhang Zongtao , Masopust Mark , Xiao Danny T.
Published: October 2013

A nanostructural hydroxyapatite (HA) coating was deposited to a porous Ti6Al4V femoral stem implant using electrophoretic deposition (EPD) to improve the bond strength, healing speed, and durable service life. The nanostructure of HA and micro-pores created in the coating can enhance the bioactivity and increase the adhesion between the implant and hard tissue. In order to achieve homogenous HA coating on the stem implant with a porous surface profile, a compensation electrode was designed and prepared. Rotation of the implant was conducted during the coating process so that a uniform coating could be achieved. The EPD combined with a dip coating was used to compensate for the complex profile and led to a homogenous coating throughout both peak and valley areas.

This developed coating process is able to deposit homogeneous HA coating on a complicated implant surface. Compared to the coating made by plasma thermal spray, the EPD HA coating can cover inner cores and exhibit a better adhesion and bioactivity. The EPD HA coating possesses significantly improved corrosion resistance compared to thermal spray HA coating. Most importantly, the biomechanical property was significantly promoted based on an in vivo animal test.
Quantifying invasion resistance: the use of recruitment functions to control for propagule pressure
Authors: Miller Alice L. , Diez Jeffrey M. , Sullivan Jon J. , Wangen Steven R. , Wiser Susan K. , Meffin Ross , Duncan Richard P.
Published: October 2013

Invasive species distributions tend to be biased towards some habitats compared to others due to the combined effects of habitat‐specific resistance to invasion and non‐uniform propagule pressure. These two factors may also interact, with habitat resistance varying as a function of propagule supply rate. Recruitment experiments, in which the number of individuals recruiting into a population is measured under different propagule supply rates, can help us understand these interactions and quantify habitat resistance to invasion while controlling for variation in propagule supply rate. Here, we constructed recruitment functions for the invasive herb Hieracium lepidulum by sowing seeds at five different densities into six different habitat types in New Zealand's Southern Alps repeated over two successive years, and monitored seedling recruitment and survival over a four year period. We fitted recruitment functions that allowed us to estimate the total number of safe sites available for plants to occupy, which we used as a measure of invasion resistance, and tested several hypotheses concerning how invasion resistance differed among habitats and over time. We found significant differences in levels of H. lepidulum recruitment among habitats, which did not match the species' current distribution in the landscape. Local biotic and abiotic characteristics helped explain some of the between‐habitat variation, with vascular plant species richness, vascular plant cover, and light availability, all positively correlated with the number of safe sites for recruitment. Resistance also varied over time however, with cohorts sown in successive years showing different levels of recruitment in some habitats but not others. These results show that recruitment functions can be used to quantify habitat resistance to invasion and to identify potential mechanisms of invasion resistance.
Correlates of Parent–Youth Discordance About Youth-Witnessed Violence: A Brief Report
Authors: Lewis Terri , Thompson Richard , Kotch Jonathan B. , Proctor Laura J. , Litrownik Alan J. , English Diana J. , Runyan Desmond K. , Wiley Tisha R. , Dubowitz Howard
Published: October 2013

Studies have consistently demonstrated a lack of agreement between youth and parent reports regarding youth-witnessed violence (YWV). However, little empirical investigation has been conducted on the correlates of disagreement. Concordance between youth and parents about YWV was examined in 766 parent–youth dyads from the Longitudinal Studies of Child Abuse and Neglect (LONGSCAN). Results showed that significantly more youth (42%) than parents (15%) reported YWV. Among the dyads in which at least one informant reported YWV (N = 344), we assessed whether youth delinquency, parental monitoring, parent–child relationship quality, history of child maltreatment, income, and parental depression were predictive of parent–youth concordance. Findings indicated that youth engagement in delinquent activities was higher in the groups in which the youth reported violence exposure. More empirical study is needed to assess correlates of agreement in high-risk youth to better inform associations found between exposures and outcomes as well as practice and policy for violence exposed youth.
Polyvictimization and Risk for Suicidal Phenomena in a Community Sample of Spanish Adolescents
Authors: Soler Laia , Segura Anna , Kirchner Teresa , Forns Maria
Published: October 2013

This study aims to provide data regarding the association between reported degree of victimization and suicidal phenomena, with special emphasis on gender differences. There were 923 adolescents recruited from eight secondary schools in Catalonia, Spain. The Youth Self-Report (YSR) and the Juvenile Victimization Questionnaire (JVQ) were used to assess suicidal phenomena and victimization, respectively.

Participants were divided into three groups (nonvictim, victim, and polyvictim groups) according to the total number of different kinds of victimization reported. Results showed that the polyvictim group reported significantly more suicidal phenomena than did the victim and nonvictim groups in both boys and girls. Furthermore, although no gender differences in reported suicidal phenomena were found in the nonvictim group, girls reported significantly more suicidal phenomena in both the victim and the polyvictim groups.

In conclusion, the results suggest that victimization may play an important role in generating gender differences with respect to reported suicidal phenomena. In addition, this study highlights the importance of taking into account the whole range of victimizations suffered by adolescents when seeking to design suicide prevention and intervention policies.
Field Tests Quantify Processes Utilizing an Enhanced Downhole Dynamics Measurement Tool for Vibration Mitigation and Performance Optimization
Authors: Veeningen Daan , Hewlett Richard , Salazar Joe , Coit Andrew , Furniss Eric
Published: October 2013

Today's drilling optimization process depends greatly upon post-well analysis of recorded downhole drilling dynamics. Sophisticated downhole sensors are limited by wireless telemetry systems that offer a relatively limited bandwidth with considerable latency. Real-time knowledge of subsurface conditions could improve drilling processes and allow the automated, closed-loop control of surface parameters based on high-frequency downhole data.

This paper describes the development and field deployment of a new, high-frequency downhole measurement tool. This tool transmits multi-sensor data in real time through a wired drillstring telemetry system, virtually eliminating latency. This enhanced dynamics tool, which acquires downhole measurements at 800Hz, includes tri-axial vibration, RPM, downhole weight on bit, and downhole torque, as well as annular pressure and temperature.

This data is instantaneously streamed to the surface and available at 80Hz for processing by surface acquisition systems. An advanced auto-driller controls the applied surface weight on bit based on the downhole dynamic measurements. Essentially, high-frequency downhole parameters become independent setpoints, supplementing information to the once-independent surface setpoints.

This paper provides details regarding a two-month field test of 6¾" dynamics tools in six wells to quantify the operational impact of the new technologies and operating processes covering vertical and directional 12½", 8¾" and 8½" hole sections. Comparison is offered for drilling both with air and with fluids, as well as drilling with positive displacement motors and with rotary steerable systems.

The field test included establishing a benchmark in the first well, followed by utilizing multi-axis vibration measurements over the course of the subsequent five wells to actively mitigate the shocks and vibrations. Operational performance was further optimized in the subsequent runs incorporating automated control of downhole weight.
Offshore Rig Integrated System and Software Requirements Verification and Validation
Authors: Haas David
Published: October 2013

Offshore drilling rigs are increasingly complex integrated systems that incorporate automated software-dependent control systems to maintain safe and effective operations. Under even relatively benign conditions, software issues have caused unintended circumstances, sometimes with catastrophic results. Catastrophic incidents and unplanned downtime are reduced when such systems are based on well-defined requirements that are verified during system development and then validated to work as intended in the operational environments.

Industry leaders, governments and international organizations are encouraging more stringent practices to improve offshore drilling operational safety. DNV and ABS standards, Integrated Software-Dependent System (ISDS) and Integrated Software Quality Management (ISQM), respectfully, aim to reduce the number of system and software issues through the application of standard software verification and validation (V&V) practices.

The aerospace industry has a long tradition for applying such discipline. In fact, it is required when working with some government agencies, such as the NASA and the Federal Aviation Administration. These disciplines contribute to the design of complex, safe, reliable, high-performance systems that allow humans and equipment to operate in the most extreme environments on Earth and in space. Over the past 12 years, operators in the offshore drilling industry have benefited significantly through application of aerospace-based systems engineering disciplines to address a wide variety of high-value rig system safety and performance issues. These processes are most effective when included during development of new rig and subsystem designs. However, significant benefit to system safety and performance can also be achieved when these processes are incorporated as part of service life extension and subsystem upgrade projects.

This paper will focus on a description of the processes and benefits to come from applying an integrated system level software requirements verification and validation approach.
How Images Can Steer a Well
Authors: Bazara Magdi , Abdulwahid Dia , Al-Sharafi Mohamed , Al Maashari Badar , Al-Kindi Zainab , Al-Shabibi Issa
Published: October 2013

Petroleum Development Oman (PDO) is considered as one of the biggest companies that work in Oil and Gas exploration and production in the Sultanate of Oman. PDO produces more than 80% of the country's crude-oil production and nearly all of its natural-gas supply. PDO Exploration takes care of the new oil fields and most of the wells become more challenging.

Well#A located in "X" field planned horizontal parallel to the top of Shuaiba reservoir. The well has many challenges such as it's an exploration well and the area contains a lot of uncertainties in structure and facies, more than one fault expected towards the well toe and the target depth & thickness uncertainties are a usual challenge. There was a real need to utilize latest logging while drilling "LWD" technologies to achieve the well objectives. Some of LWD technologies needed were "Distance To Boundary" measurements to place the well in the desired and optimum location and high quality images while drilling to minimize wire line operations risk and understand formation fracturing system.

The well successfully achieved the objectives with no sidetracks for the lateral section and a very high images quality been recorded while drilling resulted in a successful understanding for the well formation fracturing system.
Fifteen Years of Successful Coiled Tubing Re-entry Drilling Projects in the Middle East: Driving Efficiency and Economics in Maturing Gas Fields
Authors: Krueger Stefan , Gray Keith , Killip David
Published: October 2013

During the last 15 years, coiled tubing drilling (CTD) projects in the Middle East (ME) have proven an efficient and economic means of increasing and sustaining production for the oil and gas industry. CTD was implemented in 1998 and since then established as a standard, viable solution for the existing re-entry challenges in various maturing fields and applications. During this time frame corresponding technologies and procedures have been developed and continuously improved to address existing and new challenges in this growing market segment.

This paper describes the use of CTD from the first activity in Oman through operations in the Kingdom of Saudi Arabia, utilizing project data collected during 15 years of operational experience. The paper includes the technology and procedural changes that addressed new and special challenges observed within the aforementioned projects and drove production from these maturing fields such as: The coverage of low- and high-pressure reservoirs in various fields with high temperature and high H2S challenges.The movement from single re-entry wells to multilateral wellbore designs, alongside the envelope extension from pure directional wellbore placement according to plan, to real-time reservoir navigation by geo- and bio-steering processes.The introduction of special applications such as ERD and precise kick off from vertical wells with coiled tubing (CT) technology.The extension of drilling operations from overbalanced to fully underbalanced (UB) operation, with maximum N2 injection through the CT string and the requirement to deal with production while drilling.Development of other equipment to enable the pressure deployment of the BHA, allowing a move away from conventional tower set-ups to a dedicated highly mobile coil tubing rig.

The projects resulted in constant technology improvement and implementation of new developments in all aspects of CTD technology. To achieve the necessary efficiency and economic goals for the re-entry projects, new technology must include downhole bottom hole assembly (BHA) technology, casing exit equipment, surface equipment of the overall rig and other associated equipment such as the underbalanced drilling (UBD) package. Similar to the utilized technology, the corresponding procedures were also optimized and new ones introduced to adapt to changing environments and challenges.

Based on the previous and current achievements of CTD in the Middle East, this trend of adjusted developments and continuous improvements will continue to further drive project efficiencies and economics.
Extended Aramco Method- Its technico-Economic Significance in Non-damaging Drill-in Fluid Design
Authors: Amanullah Md , Allen Tim
Published: October 2013

Various sized bridging materials (SBMs) such as ultra-fine, fine, medium and coarse grade SBMs are frequently used in drill-in fluid formulations to improve drilling fluid properties, enhance mudcake quality and reduce near wellbore formation damage. The mechanical properties, especially the material toughness of the SBMs play an important role in fulfilling these functional tasks. Weak and easily disintegrating SBMs are unable to maintain the functional capability of drill-in fluid due to a major change in the planned particle size distribution in the fluid. Hence, drill-in fluid containing rapidly degrading SBMs shows poor performance while drilling. This highlights the need for selection of very tough and high strength SBMs to design superior drill-in fluid for non-damaging drilling operation in the pay zone. However, the industry lacks a suitable method for screening, testing, evaluation, quality control and quality assurance of SBM products to select the best and reject the worst and the inferior. Hence, there is a need of development of a quick and reliable SBMs characterization method to use as a guiding tool for designing superior and high performance drill-in fluid for non-damaging drilling operation.

Historically, color, provenience, origin, degree of diagenesis and metamorphism of the SBM samples or acid solubility were evaluated to use as a guiding tool to select highly durable and mechanically strong SBM products. These subjective and inappropriate methods of assessment frequently lead to disastrous SBMs performance. Due to the limitation and ambiguity of the petrographic and acid solubility methods, attempt was made to identify high quality SBMs by using Brinnel Hardness Tester. The outcome of the research was inconclusive and provided no guiding tool for SBMs performance evaluation. Failure of the above approaches lead to the development of the Aramco method for characterization, quality control and quality assurance of SBMs. Though the method is good for coarse and medium grades SBMs, it has some limitations for fines and ultra-fine SBMs. To overcome the limitations of the Aramco method, it was extended by introducing a dedicated software driven laser particle size analyzer that can measure the PSD of all grades of SBMs quickly and accurately.

This paper describes the Extended Aramco Method and its application in various SBMs evaluations to select the superior and reject the inferior for high performance drill-in fluid design. Experimental results demonstrate the universal application of the Extended Aramco Method and its usefulness in SBM performance evaluation for superior fluid formulations and non-damaging drilling operations.
"FARIIQ WAHAD" A Drilling Divisions Evolution into a Learning Organization by Engaging Mature Hires & Young National Professionals
Authors: Lichtenecker E. L. , Humoodi A. N. , Kuyken C. W. , Salem A. A. , Al-Menali A. M. , Al-Braiki A. M.
Published: October 2013

The growing Exploration & Production (E &P) industry has an increased requirement for experienced and qualified Drilling Engineers and Supervisors. The Abu Dhabi Company for Onshore Oil Operations (ADCO) has the additional difficulty that the United Arab Emirates (UAE), due to its small population, is even today dependent on expat staff and the general interest of young Emiratis in technical jobs in the oil and gas industry has been marginal.

Traditionally, ADCO has either hired a) international, mature, and experienced drilling engineers and supervisors and allocated them to various teams, putting them straight to work or b) young graduates, who were sent through the Competence Assurance Management System (CAMS) program (2 – 3 years). The quality of the work delivered usually depended on the onsite training and guidance their bosses provided them. However, ADCO is aggressively expanding and doubling its rig fleet from 23 to 46 land rigs in the next 3 years to achieve the oil production increase from 1.4 to 1.8 m bpd, which results in increased substantial staff requirement.

This paper will present ADCOs Drilling Division strategy of introducing a combination of in-house development and external certifications to attract more UAE nationals, integrate the new international staff, and cater to the specific needs of their new recruits and their respective job profiles. The role of the three in-house training modules (the CAMS Real Work Learning Academy for graduates, the Drilling Newcomers Academy for mature hires, and the TA Academy for technical assistants) as well as the as external certifications (SPE certification, Shell Round 1 &2 exam, Chartered Engineer, and MSc for Drilling Engineering and Design) is to ensure a constant career development of drilling engineers, drilling supervisors, and specialists, as well as specifically supporting Emirati nationals to gain an internationally recognized first class reputation.

As the lecturers and trainers are sourced in-house the graduates and mature hires are immediately introduced to most of their future leaders and colleagues in a proactive and hands-on environment allowing them to also share their own experiences and become regardless of their level of experience or origin: "FARIIQ WAHAD – One Team".
Perforating for Squeeze Through Four Casing Strings to Remediate Annulus Gas Leak Problem
Authors: Ibrahim Mohamed El-Sayed , Al-Neaimi Ahmed Khalifa , Hassane Mohamed Abdelsalam , Al-Mansoori Abdul Salam , Mohamed Shanof , Al-Mutwali Omar , Salsman Alan
Published: October 2013

ADMA-OPCO had integrity problems in a gas well and abandonment was the only option available to restore the integrity of the offshore multiwell jacket and revive the adjacent wells that had been shut in due to the problems. The integrity problems were oil/gas bubbles observed on the seabed around the conductor pipe and high sustained pressures in the outer cemented casing annuli. The entire jacket was considered very dangerous under these conditions.

Because the leak was determined to be located outside the 18 5/8-in. casing, perforating several intervals was required to improve the chance of a successful squeeze. Some of the intervals were perforated through 3 casing strings and the rest through 4 strings of casing; 7-in., 9 5/8-in., 13 3/8-in. and 18 5/8-in., before being squeeze cemented to cure the problem.

Modeling of the perforating gun performance indicated that penetration through the four casings could be achieved. The modeling was confirmed with laboratory testing in a mock setup to simulate worst case conditions downhole. The laboratory test results were very useful in the final gun selection process. Once the gun and deep penetrating charge type were chosen a local modification was performed to create an 18° phased gun system ideally suited to remedial applications. An optimal cement type was also chosen to be used for this application.

The perforating/squeeze jobs were executed and surface rate and pressure measurements have confirmed that the jobs were successful.

This paper will present the job preparation considerations, the prejob testing of the perforating systems, the local modification used to create the 18° phasing, the cement used for the squeeze and the confirmation that the job was successful. It is believed that this is the first time such an operation has been successfully executed and the results should be of interest to all operating companies.
Passive Inflow Control Device Autonomy - How much is too much?
Authors: Abdelfattah T. A. , Garcia G. A. , Banerjee S.
Published: October 2013

The production life of a typical well may be split into three stages. The first stage is the start-up stage, which includes flowing back completion fluid that was initially in the well. This is followed by the production of the targeted reservoir fluid and finally the last stage, which can include production of unwanted fluids such as gas or water from the reservoir.

Passive Inflow Control Devices (PICDs) have been proven to be an effective solution for controlling influx to a well in the early stages of production life. However, breakthrough of unwanted fluid is inevitable. It is at this stage that PICDs should provide a larger level of restriction at the zones in which breakthrough occurs. The level of restriction is a function of the influx rate and more importantly, the fluid properties. For fluids flowing at a higher velocity and lower viscosity, the PICDs will behave in a manner that will passively result in a larger pressure drop. In the PICD world, this phenomenon is referred to as the "Autonomous" effect.

The question remains, what level of autonomy is optimum so as not to restrict the targeted hydrocarbon production that could stem from flowing through breakthrough zones? A water cresting scenario has been simulated as a base case to demonstrate the proper level of autonomy required of a PICD. Several hypothetical PICD designs and a field proven hybrid design, with varying levels of autonomy, are demonstrated.

Simulations have been carried out for each design to assess the performance in terms of oil sweep and cumulative production. Results have shown that there is an optimum level of autonomy required before the effect becomes detrimental to the cumulative target production.
Coring Optimization: Wireline Recovery Using Standard Drill Pipe
Authors: Ahmed Hammad , Farese Travis , Mohanna Assaad , Adebiyi Ismail , Al-faraj Omar
Published: October 2013

Several days are spent during coring operations when Conventional Coring technology is being used, due to the multitude of trips in an out of the hole. Wireline retrievable coring is a unique technology offering capabilities to full bore core, drill and convey logs in a continuous operation without tripping out of the hole. This technology saves considerable time compared to multiple conventional coring runs.

Historically, one of the constraints with large diameter wireline coring systems is the requirement to pick up specialty drill pipe. This specialty drill pipe provides an internal diameter large enough to accommodate the retrieval of the inner components, utilized to cut 3" to 3.5" diameter core. Moreover, another constraint with large diameter wireline coring systems is the inability to run a jar within the drill string, due to internal diameter limitations.

A new wireline retrievable system capable of acquiring 3" diameter core utilizing standard 5 ½" × 4" drill pipe was designed for application on Saudi Aramco wells. In addition, custom large bore coring jars were designed and deployed to meet the operator's stuck pipe mitigation requirements. With several runs made, the newly designed wireline coring system brings a step change to coring technology, and increases its operational efficiency.

The improvement in this technology has drastically increased the efficiency of large diameter wireline retrievable coring technology and greatly improved the economics.
Utilization of Key Performance Indicators and Benchmarking Improves Drilling Performance for Several Operators
Authors: Saeverhagen Erland , Bouillouta Fouzi , Baksh Nazaad , Hughes Baker , Vettical Celestine
Published: October 2013

There have been significant developments in the evolution of well data aggregation, storage and analytics over the past two decades. Initially, trends were captured on chart recorders and paper charts in the mud logging units, where decisions were based on the experience of the personnel at the rigsite. In general, rig operations were usually successfully completed with the technology available at the time. However, with economic downturns, increased competition, and variations in oil and gas prices, the upstream industry has become far more cost and efficiency sensitive, requiring increased focus on non-productive time (NPT), whether it is due to failures or inefficiencies in the daily operation – we refer to this as Performance Opportunity Time (POT).

Through the definition of operational key performance indicators (KPI) and the introduction of intelligent software to calculate and benchmark these KPIs, POT or "flat time" on the drilling curve has been significantly reduced by critically analyzing certain work tasks at the rigsite, combined with remote services. The ability to compare the operational time breakdown for the same type of operation in near real-time across multiple rigs provides the operator with significant insight on the level of operational efficiency at each rig. In combination with remote advisory services, this provides a powerful solution to improve on operational performance

This paper illustrates how operational KPI data have been analyzed and benchmarked to enable active focus on recorded POT and the subsequent positive results.
Downhole Vibration Analysis: Fishing Agitation Tool Efficiency in Stuck Pipe Recovery
Authors: Voghell Mark , Mohanna Assaad , Hanley Christopher , Al-Khiriseh Cristinel , Al-Mousa Ahmed , Al-Amri Ali
Published: October 2013

A challenging and costly situation to overcome in modern day directional drilling applications is stuck pipe in open hole due to differential and/or mechanical sticking forces. Chances of recovery decay with time and conventional fishing with a bottomhole assembly (BHA) is frequently unsuccessful. By incorporating downhole axial-oscillation technology, the fishing reliability and effectiveness improve exponentially. The Fishing Agitation Tool (FAT) is an excitation component of the fishing BHA used to deliver low impact, high energy oscillation to the engaged fish. The FAT keeps the string in motion, breaking static sticking friction.

The FAT was used in Saudi Arabia for the first time to recover differentially stuck BHAs from a 6 1/8 in. hole in deep, high angle wells. The initial application involved pipe that was stuck in hole for more than 12 days without any movement, during which several conventional fishing BHAs failed. FAT was run in the final fishing BHA, getting the fish free after an hour of axially agitating and stroking the fish. After the pilot field trials in Saudi Arabia, and several successes in recovering mechanical and differential stuck BHAs, downhole vibration analysis proved the FAT effectiveness in assisting fishing BHAs in recovering stuck pipe more efficiently.

The FAT offers a new level of fishing technology that maximizes the effect and reliability of fishing BHAs in challenging wellbore environments, where conventional fishing techniques are deemed insufficient. This increased efficiency offers substantial reduction in fishing lost time, and an increased potential for fish and well recovery.

This paper investigates the effectiveness of the Fishing Agitation Tool through a study of the impact forces, impulse and drag forces generated by the FAT compared to conventional jarring operations, utilizing drag modeling as well as jarring analysis software.

Successful cases histories are reviewed to highlight the benefit of this technology.
An Innovative Ball-Activated Multi-Cycle Circulation Valve for Completion and Drilling Applications
Authors: Ali Mohsen , Hern Gregory , Xu Yang
Published: October 2013

Circulation valves are used in drilling and completion applications in a variety of configurations. They are used in the tool string to boost annular velocity, remove debris from the wellbore, perform well integrity tests, enable fluid movement between tubing and casing, and prevent pulling a wet string. In many applications, multiple cycles (open and close) are required to in order to complete multiple tasks in one trip. Multiple cycles can be achieved using mechanically activated circulation valves. However, in some configurations mechanically activated circulation valves require a hard bottom to manipulate the tool string. Consequently, a hydraulically activated multi-cycle circulation valve is desired in many applications, especially in deep wells, deviated wells, and drilling applications.

An innovative ball-activated multi-cycle circulation valve (BAMCCV) has been developed for these applications. The circulation valve provides three flow modes: to the bit only, to the circulation ports only, or a split flow between the bit and circulation ports. Three different size activation balls are used to manipulate the BAMCCV to these flow modes. In cased hole displacement, openhole drilling, and wellbore cleanup applications, flow can be split to maximize annular velocity for improved debris transport. In openhole drilling applications the BAMCCV can also be used in the circulation ports-only mode when lost circulation material must be spotted. This prevents spotted fluids from entering sensitive and expensive equipment such as measurement-while-drilling (MWD) and logging-while-drilling (LWD) tools. Blocking flow to the bit may also be desirable to maximize flow through the circulation ports when flushing debris out of recesses in blowout preventers. The decision whether to allow flow or to not allow flow to the bit when the circulation ports are open can be implemented at any time. The circulation ports can be opened and closed in the BAMCCV up to seven times. This enables greater efficiency in downhole operation by enabling multiple functions in a single trip. This paper presents the design, engineering, testing, field trial results, application and function of this new circulation valve.

The innovative BAMCCV can be used in a wide range of applications, and can be manipulated between three flow modes by dropping the correctly size ball. It enables performing multiple operations in one trip, and provides flexibility in selecting flow modes in response to well conditions. This flexibility is particularly important in deep, deviated, and problematic wells.
1st successful 6-1/8" Long Horizontal Hole (9,000 ft) Steering into a 2ft thick High Temperature Reservoir and Completed with 4-1/2" × 3-1/2" Slotted Liner. "UAE Case History"
Authors: Bin Shamlan Abdulla M. , Torres Fernando , Ben Romdhane Mourad , Al Kholy Ahmed B. , Abou Mostafa Suliman , Al Hammadi Adel M. , Abd Mokhti Mohd Ridzuan
Published: October 2013

ADCO aspires to push the established local boundaries via a new drilling campaign to develop 24 long horizontal wells. These wells have 9,000ft of horizontal section in deep and tight reservoirs targeting two zones that are only 3ft thick separated by a stylolite. The challenges of this project include drilling 1,500 ft. TVD deeper than previously done to land the wells, stepping down through 3ft styllolite and extending the horizontal section 260% further than the typical wells (3,400ft) in the same reservoir. To reach the proposed thin target requires intensive engineering work in the planning stage (e.g. Selection of downhole tools, casing selection, trajectory planning and mud/chemical selection.

The project started with pilot wells of 6,000ft and 7000ft. horizontal sections to gather information before proceeding with the 24 long horizontal wells. Front End Engineering phase was performed to ensure the capability of the chosen rig. Additional simulations were performed for critical operations; this is ended up in the successful run of 9000ft of slotted liner to TD. Detailed modeling and selection of appropriate LWD measurements were done to land the well and geosteer the long horizontal hole successfully throughout the reservoir. Lab tests were carried out for the selection of the lubricant to be used under challenging reservoir conditions. T&D models were calibrated while drilling the pilot Horizental sections to ensure that the first ERD well could be delivered safely, meeting all well objectives.

All learning from the pilot wells was captured and as a result the first ERD well in deep and tight reservoir was drilled to TD. This well achieved the longest well drilled with chemical R/A source in UAE. Excellent geosteering work was achieved for the successful well placement. The hole was drilled and tandem slotted liners run to bottom smoothly. ECD management played a vital role to minimize losses since the well was drilled close to its fracture limit. Lubricant proved to be compatible with the mud at high temperature (+280 degree F), avoiding foaming formation. All sections were drilled shoe to shoe successfully.
Systematic Approach to Optimize the Rig Move within ADCO Onshore Field
Authors: bin Sumaida Ali Sulaiman , El Gebaly Mohamed Ahmed , Loayza Alvaro F. , al Hammadi Adel , Abu aish Abdel Nasser
Published: October 2013

ADCO's Business Plan demands a high number of wells to be delivered in development Fields for better reservoir sweeping efficiency such as: Infill drilling, injector's patterns and maintenance work-over operations in the end of each year, that result in increase of 50% of rigs fleet to meet the DWS (Drilling work over schedule) requirements in the next 5 years because the expansion in production will be from 1.4 MM bpd to 1.8 MM bpd. The rig move is an important component in the DWS as the average rig move between the wells is 4.6 days which in total 110 days and that is our driver to minimize the time consumed in rig move and gain more days for BP

This Presentation will develop a study case for rig move optimization in BAB and ASAB Fields. In general two possible operation to move rigs are followed in our company: Mast-Up when the road allow us to do that, or conventional movement Mast-Down, if there are any obstacle in the way, like power lines, conductor lines or limited spaces (these movement requires additional time for laying down and rigging up the mast).

The main idea of this study was to analyze the wells planned for BAB and ASAB fields individually for the next year and assign the rigs in order to avoid the movements Mast-Down, additionally trying to minimize the distance for the movement of the rigs and to accelerate the movement. Keeping this in mind the first step was plot all the wells planned in the original schedule and try to find nearest locations in reasonable time sequence, reassigning wells between rigs, also noting the power lines and pipes already in place, minimizing the crossing of these. Subsequently a review of the initial scenario and the proposed one was issued and all the possible savings in time and money were calculated. We found savings in ASAB field estimated in 60 days and 8 MM $, for BAB field the savings are 390 day and 19 MM $