bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of Locally Resonant Structures for Sonic Barriers
Authors: Hall Andrew , Calius Emilio , Dodd George , Wester Eric , Chan KL
Published: December 2014

The application of metamaterials or structured material principles to sound insulation has produced a new isolation concept known as locally resonant structures (LRS). LRS combine interacting components specifically arranged to generate localised resonances within the structure. LRS have exceptional sound transmission loss (TL) performance in defined frequency bands, which can be tailored for any desired region of the spectrum. Low frequency noise (below 1 kHz) is where irritating acoustic intrusion frequently occurs but is both challenging and expensive to prevent with conventional solutions, and where the LRS is a potentially compact and relatively lightweight solution. Numerical models based on networks of single-degree of freedom oscillators were used to understand how the components of the LRS can be manipulated to generate a designated TL performance spectrum. Designs with the desired TL characteristics were then modelled using FEA software, and samples were fabricated for testing. This paper will focus on results obtained by testing the LRS samples in an impedance tube adapted for TL experimentation. These results showed that the highest performing network arrangements combined layers of multiple resonators with incremental resonant frequencies to increase system bandwidth. Experimental data for various LRS arrangements shows good correspondence to modelling predictions. Samples yielded systems with attenuation peaks of 80dB over band widths approaching 350 Hz at frequencies well below 1 KHz These results provide insight into the benefits and limitations of complex LRS, and how to use this technology for practical applications.
Foreword
Authors: Metsmägi Iris , Sedrik Meeli , Uusküla Mari
Published: December 2014

Foreword
Prospect Theory Explains Newsvendor Behavior: The Role of Reference Points
Authors: Long Xiaoyang , Nasiry Javad
Published: December 2014

Current understanding in operations management is that prospect theory, as a theory of decision making under uncertainty, cannot systematically explain the ordering behavior observed in experiments on the newsvendor problem. We suggest this is because the newsvendor’s reference point is assumed to be the status quo, i.e., zero payoff. We propose an alternative based on newsvendor’s salient payoffs and show that prospect theory can, in fact, account for experimental results.

This paper was accepted by Serguei Netessine, operations management.
Discussing the Igbo language on the Igbo Internet radio: Explicating ethnolinguistic vitality
Authors: Onuzulike Uchenna
Published: December 2014

There is a growing concern about the decline and possible extinction of the Igbo language. The Igbo are primarily located in the south-eastern part of Nigeria. This study analysed four interviews on Igbo Radio, an Igbo Internet radio station, to ascertain how Internet radio is being utilized in discussing the decline of the Igbo language. Drawing on ethnolinguistic vitality theory, this qualitative study triangulates four selected interviews on Igbo Radio, the website, and personal observations for the analysis. Three salient themes emerged: (1) decline and challenges of the Igbo language, (2) second-generation immigrants and the Igbo language, and (3) sustaining the Igbo language. The findings suggest that Igbo parents appear to have less vitality; as a result, they tend not to teach their children Igbo.
From digital switchover to austerity measures: A case study of the Cypriot television landscape
Authors: Nicoli Nicholas
Published: December 2014

In April 2013 Cyprus and the Troika (the European Commission, the European Central Bank and the International Monetary Fund) reached an agreement aimed at addressing the country’s financial imbalances by leading the Island through a series of austerity measures. This article addresses the Cypriot digital television landscape three years following digital switchover (DSO) and currently in the midst of austerity measures. The article draws on long-term historical analyses combined with discourse analysis of current policy decisions, media coverage and expert interviews with the main stakeholders. It is divided into five sections. The first situates the case study within an appropriate theoretical framework. The second sheds light on Cyprus’ turbulent history and how it has affected the development of the media sectors. Next, it offers an overview of digital television in Cyprus and highlights how the main players had positioned themselves in the market before the country sunk into a deep recession. The fourth section underlines the financial crisis and the resulting austerity measures that have affected Cyprus, especially since 2012/2013. In the fifth and final section, the work focuses on the current situation, paying particular attention to how political and market-driven agendas have collided, with the example of the digital terrestrial television (DTT) platform Velister.
The mediatization of celebrity politics through the social media
Authors: Wheeler Mark
Published: December 2014

This article provides an analysis of celebrity politics within the public sphere. As there has been a commodification of digital media services, the lines between politics and entertainment have been blurred. With the rise of talent shows, rolling news channels, Web 2.0 networks and user-generated online content, celebrity has become instantaneous and may be orchestrated in viral terms. Therefore, this analysis will consider how politicized celebrities (CP2s) have received a greater amount of coverage with reference to social networks such as Twitter and Facebook to associate themselves with endorsements, causes and activities. The article will provide a case study of the online dispute that occurred amongst film, television and music stars concerning Israel’s 2014 military action within Gaza. Finally, it will reflect upon whether celebrity activists’ use of the social media can reinvigorate politics or will such activity erode the political culture.
Beryl Reid Says… Good Evening: Performing queer identity on British television
Authors: White Rosie
Published: December 2014

Beryl Reid Says… Good Evening (1968) was a comedy revue series broadcast on BBC television in the late 1960s that showcased the talents of a renowned British character comedy performer. Beryl Reid’s career spanned music hall, variety theatre, dramatic acting, radio comedy, film and television. She was a celebrity figure from the 1950s to her death in the 1990s but never became a ‘star’ as such. Reid’s work is addressed as a form of queer performance, both in roles that reference lesbian sexuality and roles that depict eccentric femininities. This television series was one of the few attempts to showcase her talents, and it is discussed here as an example of how character comedy queers heteronormativity through its camp attention to the everyday.
Encounters between legal systems: recent cases concerning Islamic commercial law in secular courts
Authors: Foster Nicholas H.D.
Published: December 2014

Nicholas H.D. Foster, School of Law, School
of Oriental and African Studies, University of London considers
questions concerning Islamic law, including its suitability for
the modern commercial world and the appropriateness of
western-style courts for enforcement of the shari'a. An article
published in Amicus Curiae – Journal of the Society for Advanced
Legal Studies at the Institute of Advanced Legal Studies. The
Journal is produced by SALS at the IALS (Institute of Advanced
Legal Studies, School of Advanced Study, University of
London).
Legal approaches to the burial rights of a surviving wife
Authors: Nwabueze Remigius N.
Published: December 2014

Article by Dr Remigius N. Nwabueze (City
Solicitors' Educational Trust Lecturer in Property Law at the
School of Law, University of Southampton; Leverhulme Research
Fellow; Visiting Fellow of the Institute of Advanced Legal
Studies) published in Amicus Curiae - Journal of the Society for
Advanced Legal Studies. The Journal is produced by the Society
for Advanced Legal Studies at the Institute of Advanced Legal
Studies, University of London.
Legal and responsible?
Authors: Lynch-Wood Gary
Published: December 2014

Consideration of policies on Corporate
Social Responsibility and responses from the legal profession.
Article by Gary Lynch-Wood (Lecturer in Law at the University of
Manchester) published in Amicus Curiae - Journal of the Society
for Advanced Legal Studies. The Journal is produced by the
Society for Advanced Legal Studies at the Institute of Advanced
Legal Studies, University of London.
The Fraud Act 2006: has it had any impact?
Authors: Summers Ben
Published: December 2014

Article looking at the impact of the Fraud
Act 2006 - the most radical change in the law of criminal fraud
in England and Wales since the Theft Act 1968. Article by Ben
Summers (Partner, Peters & Peters) published in Amicus Curiae
- Journal of the Society for Advanced Legal Studies. The Journal
is produced by the Society for Advanced Legal Studies at the
Institute of Advanced Legal Studies, University of
London.
Draconian and manifestly unjust: how the confiscation regime has developed
Authors: Lawrence Sir Ivan
Published: December 2014

Article taken from a speech on the law of confiscation given by Sir Ivan Lawrence QC at the 26th Cambridge International Symposium on Economic Crime at Jesus College, Cambridge, on September 5, 2008. Article by Sir Ivan Lawrence QC. Sir Ivan was a Member of Parliament for 21 years, and chaired the Home Affairs Select Committee dealing with issues of Law and Order for five years. A Queen's Counsel for 27 years, and a Recorder of the Crown Courts for 19 years, he practises at the Criminal Bar. Amicus Curiae is the Journal of the Society for Advanced Legal Studies. The Journal is produced by the Society for Advanced Legal Studies at the Institute of Advanced Legal Studies, University of London.
Can genocide, crimes against humanity and war crimes be pardoned or amnestied?
Authors: Ahmed Anees , Quayle Merryn
Published: December 2014

Article based on a lecture made at the
Institute of Advanced Legal Studies on January 28, 2008
considering war crimes and the role of international tribunals
and international criminal court. Article by Anees Ahmed and
Merryn Quayle published in Amicus Curiae - Journal of the Society
for Advanced Legal Studies. The Journal is produced by the
Society for Advanced Legal Studies at the Institute of Advanced
Legal Studies, University of London.
Multilevel preconditioning for sparse optimization of functionals with nonconvex fidelity terms
Authors: Dahlke Stephan , Fornasier Massimo , Friedrich Ulrich , Raasch Thorsten
Published: December 2014

This paper is concerned with the development of numerical schemes for
the minimization of functionals involving sparsity constraints and nonconvex fidelity terms. These functionals appear in a natural way in the context of Tikhonov regularization of nonlinear inverse problems with ℓ1 penalty terms. Our method of minimization
is based on a generalized conditional gradient scheme. It is well known that these algorithms might converge quite slowly
in practice. Therefore, we propose an acceleration which is based on a decreasing thresholding strategy. Its efficiency relies on certain spectral
properties of the problem at hand.
We show that under certain boundedness and contraction conditions the resulting algorithm is
linearly convergent to a global minimizer and that the iteration is monotone with respect to the Tikhonov functional.
We study important classes of operator equations to which our
analysis can be applied. Moreover, we introduce a certain multilevel preconditioning strategy which in practice promotes the
aforementioned spectral properties for problems where the nonlinearity is a perturbation of a linear operator.
On the Piecewise Linear Exact Solution
Authors: Pogorilyi Oleksandr , Trivailo Pavel M. , Jazar Reza N.
Published: December 2014

In this paper we will show how the exact frequency
response of the piecewise linear vibration isolator
can be reduced to be found by solving only two transcendental
equations. Adopting a new nondimensionalization
method, the mathematical modeling of the system is presented
and the mathematics to determine the exact steadystate
response of the system is explained.
Social Consensus and the Meta-Regulation of Land-Taking Disputes in Vietnam
Authors: Gillespie John
Published: December 2014

Scholars have shown that Vietnam’s authoritarian regime responds to citizens. They speculate that this responsiveness may arise from rules within the party regime, citizen engagement, and a strategy that offers preferential treatment to a narrow group of supporters. This article adds to this literature by showing how intermediaries leverage their personal relationships within the party and state to circumvent formal legal and political hierarchies and broker solutions to complex land-taking cases. It uses ethnographic studies of land-taking disputes to explore the limits of law and legal authority in resolving these disputes and analyze how intermediaries use informal dialogical exchanges to sensitize officials to the needs of land users and to increase land compensation. Dialogue not only resolves misunderstandings and promotes understanding, more importantly it gives the parties a common set of norms and assumptions to work toward. However, such dialogue has not completely succeeded in resolving the complexities of land-taking cases in Vietnam.
Economic aspects of lfa and organic farming payments in Latvia
Authors: Veveris Armands , Lakovskis Peteris , Benga Elita
Published: December 2014

Less favoured area (LFA) payments and organic farming (OF) payments represent a third of all public funding available for RDP 2007–2013 in Latvia and are used by about two- thirds of all farms. The aim of the study is to assess the economic impact of LFA and OF payments. The data from Rural Support Service, FADN and statistics of agricultural sector were used to conduct the study. A group of farms receiving support payments was compared with a group without this kind of support, in order to evaluate the impact of support payments. The results show that LFA payments have facilitated a significant income growth, especially for small farms. They have also contributed to more intense use of the land. Since OF support has not contributed enough to the agricultural production, direct payments to production will increase economic impact of support payments.
Passive Semantic structures in the narratives of children: A Hungarian-Tunisian Arabic comparative developmental study
Authors: Fekete Gabriella , Darine Saïdi
Published: December 2014

E tanulmány célja a magyar és tunéziai arab gyerekek és tinédzserek elbeszélő szövegekben használt olyan nyelvi formáinak összegyűjtése, amelyek a cselekvés elszenvedőjét helyezik előtérbe. A vizsgált szöveg magyar és tunéziai arab anyanyelvű gyerekek, tinédzserek és felnőttek elbeszéléseiből áll. Az adatrögzítéshez használt anyag a Frog, where are you? (Mayer, 1969) című képeskönyv volt. Eredményeink azt mutatják, hogy a több résztvevős eseményt tartalmazó tagmondatok aránya, valamint az esemény elszenvedőjének előtérbe helyezése a kor előrehaladtával nő mind a két nyelvben. Bár a magyar és a tunéziai arab tipológiai szempontból két teljesen eltérő nyelv, a beszélők ugyanazokhoz a nyelvi formákhoz folyamodnak (szórend változtatása és mediális igék alkalmazása) a passzív igenem szemantikai funkciójának betöltésére.
Numerical analysis of submerged flows for jet grouting
Authors: Modoni Giuseppe , Wanik Lidia , Giovinco Gaspare , Bzówka Joanna , Leopardi Angelo
Published: December 2014

The diffusion of turbulent submerged flows is studied to understand the core mechanism of jet grouting and to enhance the efficiency of treatments. Because of the particularly high speeds, experimental measurement is very difficult, and theoretical relationships found at lower velocities are misleading. The velocity distribution and its relationship with the injection parameters are then obtained, combining experiments, numerical calculations and theory. A numerical finite-volume model simulating the turbulent propagation of submerged jets is initially calibrated using a set of experimental data reported in the literature. This model is used to perform a parametric study, varying the injection parameters within the typical range of jet grouting and evaluating their influence on the velocity distribution. The results of numerical calculations are finally interpreted with a mathematical function relating the velocity distribution to the nozzle diameter, inlet velocity and fluid composition. The effect of insulating the injected fluid with a coaxial air jet is also investigated, to clarify the principles of double- and triple-fluid jet grouting systems.
Effect of Porphyromonas gingivalis Lipopolysaccharide on Bone Marrow Mesenchymal Stem Cell Osteogenesis on a Titanium Nanosurface
Authors: Xing Helin , Taguchi Yoichiro , Komasa Satoshi , Yamawaki Isao , Sekino Tohru , Umeda Makoto , Okazaki Joji
Published: December 2014

Background: Titanium (Ti) dental implants have been widely used for prosthetic reconstruction of dentition. Unfortunately, peri‐implantitis can result in failure of dental implant osseointegration. Lipopolysaccharide (LPS) acts as a chronic inflammatory stimulus and maintains peri‐implant inflammation, worsening the prognosis for implant osseointegration. The purpose of this study is to determine the effects of 10 M NaOH‐modified Ti surface with nanonetwork structure on the proliferation and osteogenic differentiation of rat bone marrow mesenchymal stem cells (BMMSCs) in the context of Porphyromonas gingivalis LPS exposure.

Methods: Titanium disks treated with 10 M NaOH solution and control were incubated with BMMSCs and exposed to P. gingivalis LPS (0, 0.1, or 1 μg/mL). The effects of the modified nanonetwork structure on osteogenic differentiation of rat BMMSCs were evaluated in the context of different concentrations of P. gingivalis LPS exposure.

Results: Rat BMMSCs on the 10 M NaOH‐modified Ti surface with nanonetwork structure had higher levels of osteogenesis‐related gene expression and significantly greater cell proliferation, alkaline phosphatase activity, and extracellular matrix deposition and mineralization than cells on the untreated Ti surfaces, in all the groups with different doses of P. gingivalis LPS exposure.

Conclusion: The 10 M NaOH‐modified Ti surface with nanonetwork structure has better endotoxin tolerance under P. gingivalis LPS exposure than the non‐modified surface.
Evaluation of Biochemical Parameters and Local and Systemic Levels of Osteoactive and B‐Cell Stimulatory Factors in Gestational Diabetes in the Presence or Absence of Gingivitis
Authors: Gümüş Pınar , Özçaka Özgün , Ceyhan‐Öztürk Banu , Akcali Aliye , Lappin David F. , Buduneli Nurcan
Published: December 2014

Background:Gestational diabetes mellitus (GDM) is defined as varying glucose intolerance, with first onset or recognition in pregnancy. This study evaluates clinical and biochemical parameters in a possible association between GDM and gingivitis.

Methods:A total of 167 pregnant females was included in the study. There were 101 females with GDM and 66 females without GDM. Subgroups were created according to the presence or absence of gingival inflammation. Plaque index, bleeding on probing, and probing depth were recorded at four sites per tooth. Serum, saliva, and gingival crevicular fluid (GCF) levels of interleukin (IL)‐6, IL‐8, soluble receptor activator of nuclear factor‐kappa B ligand (sRANKL), osteoprotegerin (OPG), B‐cell activating factor (BAFF), and a proliferation‐inducing ligand (APRIL) were determined by enzyme‐linked immunosorbent assay. Data were analyzed by Kruskal‐Wallis and Mann‐WhitneyUtests and Spearman correlation analysis.

Results:Age and anthropometric indices were higher in the GDM than non‐GDM group (P<0.0001). Clinical periodontal recordings, serum BAFF, IL‐8, and saliva sRANKL levels were higher in the GDM group (P<0.05). Saliva IL‐6 level was higher in the GDM with gingivitis group than non‐GDM with gingivitis group (P= 0.044). Serum and GCF BAFF (P<0.0001), serum, saliva, and GCF APRIL (P<0.0001;P<0.0001;P= 0.032, respectively), GCF OPG (P= 0.036), and serum and saliva sRANKL (P<0.0001) were higher in the GDM with gingivitis group than GDM without gingivitis group.

Conclusions:The inflammatory response seems to be more pronounced in females with GDM. The observed increase in both local and systemic levels of inflammatory cytokines may suggest an interaction between gingivitis and GDM.
Development of New Kill Fluids with Minimum Sagging Problems for High Pressure Jilh Formation in Saudi Arabia
Authors: AlAbdullatif Ziad , Al-Yami Abdullah , Wagle Vikrant , Bubshait Abdulaziz , Al-Safran Ali
Published: December 2014

A successful kill fluid formulation for the overpressured Jilh formation has been achieved. Jilh formation is a dolomitic middle Triassic tight zone that ranges from 8,000 to 10,000 ft TVD with abnormal salt-water pressure that requires a kill fluid with a density up to 150 lb/ft3 (pcf). Addition of weighting materials such as barite (BaSO4) or hematite (Fe2O3) is needed to achieve the desired density for the kill fluid. However, maintaining high volume of solid content for barite particles (or any other weighting material) in suspension is challenging, especially for extended period of time. This phenomenon is described in the industry as static barite sag and it may lead to serious well control incidents and lost circulation.

Saudi Aramco developed a new formula for kill fluids at high range of densities up to 150 pcf using barite with manganese tetroxide (Mn3O4). No similar formulations were developed before to the best of the authors' knowledge. The properties of small particle size (D50=1 μm), spherical shape, and high specific gravity (4.95 g/cm3) of manganese tetroxide make it a good weighting material to reduce solids loading and settling compared to barite (SG= 4.20 g/cm3 and D50=20 μm). Results show that the density variation between the upper and lower section after 24 hours of vertical static condition is 5 pcf for the new formula (density= 150 pcf) compared to a variation of 13 pcf for the conventional formula that has barite only. When the drilling fluid is put in inclined static condition for 24 hours, the density variation is 6 pcf for the new formula (density= 150 pcf). However, the conventional formula showed a density variation of 17 pcf.

The experimental work in this paper involved rheological properties, thermal stability, HT/HP filtration, and static sagging. This paper also describes field cases with barite sagging in high temperature wells and method and formulation of combining manganese tetroxide and barite to formulate new kill fluid formulations for Jilh Formation in Saudi Arabia fields.
Successful DST Methodology Adopted in Highly deviated, Deep, Sour & HPHT Exploratory well: A Case Studie
Authors: Al-Ibrahim Abdulla , Al-Bader Haifa , Al-Salali Yousef , Duggriala Vidya sagar , Ayyayo Manimaran , Subban Packirisamy
Published: December 2014

Exploration in the state of Kuwait focuses on finding light oil and gas from deeper, HPHT and naturally fractured tight gas and condensate Jurassic Reservoirs. These reservoirs are drilled with high Oil Base Mud (OBM) densities(16-20.8ppg). The existing surface and subsurface constraints resulted in changing the proposed well location, which resulted in changing the well profile from vertical to highly deviated well. Having a deep HPHT well in highly deviated manner causes more complexity while drilling and testing the Jurassic formations. 78.2-degree angle deviated well with several side tracks and two doglegs was drilled to a depth of around 20,000-ft.(MD) to delineate the potential of the deep reservoirs. Well intervention operations were considered potentially risky due to the presence of hazardous well conditions such as HPHT and high H2S concentration. Keeping in view of well profile and hostile environments, it was very challenging task to conduct a short term well testing (STT) in these deep reservoirs.

Tractor was used in the highly deviated sections with more than 50-degree angle to record the cement quality logs with Wireline. The target formations were perforated using high temperature and high shot density TCP guns in overbalance condition using drill-pipe. Two separate Drill Stem Tests (DST) consist of tester valve, multi-cycle circulating valve, two rupture disc valves, Down-hole sampler and Down-Hole memory gauges were used to test two different deep high pressure and sour reservoirs. Using of 15K Coiled Tubing with total length of 20,000ft for well activation and stimulation assisted the well intervention during the STT.

Careful planning, proper selection of equipment & materials, detailed well test program and procedures resulted in a safe and successful testing operations in such extreme well conditions such as unconventional well profile, HPHT, and presence of H2S. For the first time in Kuwait, a highly deviated exploratory well with complete set of DST tools was successfully tested and proved significant amount of light oil and gas from a hostile reservoir.

This paper describes and discusses the challenges encountered while drilling and testing an exploratory well and the achievement of overcoming these challenges which leads to successful well testing.
Higher Recoveries and Sustained Production Following Structured Multi-Disciplinary Reviews: A Case from Offshore Nigeria
Authors: Sonde Adekoyejo Babatunde , Emesi John Chukwudi , Avu Albert A. , Oladipo Titilola
Published: December 2014

Getting the maximum possible recovery from existing developments safely is at the heart of the Wells Reservoirs and Facilities Management (WRFM) processes of Shell Companies. WRFM in Shell seeks to keep deferments and natural production decline rates as low as possible and optimise production in line with field WRFM philosophy (minimal pressure depletion, keeping producing GOR below a threshold, keeping well head pressure and surface vessels within a defined envelope, etc). At the foundation of this efficient WRFM lies a thorough and current understanding of the entire production system, one of the ways by which this is achieved is via a system of multi-discipline (daily, quarterly, annual and ad-hoc) reviews developed within Shell and for Wells, Reservoirs and Facilities Management to enable quick understanding of deviations and quick decision making and quick corrective actions.

These reviews are applied in the field under discussion. The King Field is located offshore Nigeria and has been operated for over a decade. Increasing water production with an attendant oil production decline is the most critical concern in the field. Good WRFM practices have therefore become more important than ever to safely and optimally produce hydrocarbons from the field.

In one reservoir, decisions and actions following from systematic reviews resulted in the restoration of production to two producers and increased production from two other producers by artificial lift opportunity identification and execution in the wells with the following benefits: Increase in reservoir ultimate recovery.Optimal use of installed FPSO capacity.

Similar applications of structured multi-discipline reviews to developed reservoirs have the potential to improve the recovery efficiency of these reservoirs using "common place" technologies such that a small increase in recovery factors could cumulatively result in an immense increase in production from developed fields at minimal expenditures.
Synergistic Chemistry Tailors Invert Emulsion Fluids (IEF) with Consistent Rheology to Minimize Equivalent Circulating Density (ECD) Fluctuations
Authors: Kulkarni Dhanashree , Maghrabi Shadaab , Wagle Vikrant
Published: December 2014

Consistent rheology is crucial for the successful construction of a deepwater oil/gas well. Oil wells with water depths greater than 5,000 ft are an industry norm, with temperatures at the seabed close to 40°F. There is a continuous need to drill with products that are environmentally-acceptable and yet technically capable. At cold water temperatures, invert emulsion fluids (IEFs) typically exhibit a significant increase in rheology, becoming noticeable in the riser after static periods. To break circulation after static periods or while circulating, the high rheology of the IEF necessitates high pump pressures to initiate or maintain circulation. High pump pressures mean high equivalent circulating densities (ECDs) at the bottom of the well, increasing the probability of losses. Fluid losses in deepwater wells can be costly, considering the difficult logistics.

Traditionally, thinners are added to the IEF to pre-empt an increase in rheology in cold waters and to help minimize the ECD. This entails precise control over the rheology of the IEF along the depth of the well, especially in the hotter regions. Failing this can result in the poor suspension of barite or drilling cuttings. A desirable IEF has a consistent rheology from the platform to the riser and to the bottom of the well.

Wagle et al. (2012) describe an organic rheology modifier (ORM) that delivers a consistent rheology to the IEF in temperatures ranging from 120 to 400°F at 18,000 psi. Taking this a step further, an additive to the ORM (AORM) was developed that synergistically interacts with the ORM in the IEF. The IEFs formulated with the AORM and ORM in three base oils common to deepwater operations demonstrated the following:

Consistent rheology from 40 to 150 to 350°F at 15,000 psi and higher. Improved suspension to barite particles.

Furthermore, both the AORM and the ORM passed the stringent toxicity and biodegradation required for use in the North Sea.
Engineering, Procurement, and Construction Challenges of Oil and Gas Artificial Islands in the Arabian Gulf, Part 2: Settlement Prediction of Shallow Foundations
Authors: El-Gharbawy Sherif , Fioravante Vincenzo , Giretti Daniela
Published: December 2014

The Abu Dhabi oil and gas industry, represented by ADNOC companies, is currently developing an array of artificial islands across its Exclusive Economic Zone in the Arabian Gulf for applications ranging from new field development and upgrade or expansion of storage and offloading facilities, to the creation of accommodation villages for offshore personnel. With favorable water depths and environmental conditions, land reclamation is often a more economical option than the construction of fixed steel jacket platforms. ADMA-OPCO is currently engaged in applying land reclamation technology to projects such as the Satah Al-Raaz Boot (SARB) field development and the Das Island Development (DID). SARB is a 105-mbd development comprising 86 wells on two artificial islands. While cost and schedule optimization will be realized with the selection of the land reclamation and artificial island option for these mega projects, geotechnical and marine engineers are facing project-specific challenges such as the development of performance criteria for the fill material used in the construction of the islands and assessment of the ground improvement works. The fill material consists of natural soil (biogenic carbonate sand) dredged from the local environment with varying fines content and mechanical characteristics. Once deposited, the sand is compacted to achieve target performance. The major geotechnical issues related to the performance of fill material are its deformability under the working loads of the drilling facilities, which are generally founded on shallow footings, and its resistance and deformability during seismic loading. A method for the computation of short term settlements of shallow foundations under static loadings is proposed. The method, which has been implemented on a worksheet to provide a simple computational tool, is based on the use of the equivalent linear elasticity and is verified by means of model plate load testing of the fill material conducted in the centrifuge laboratory and zone load tests conducted on the SARB islands.
Effect of CO2 Sequestration Period on the Mechanical Properties of Carbonate Aquifers
Authors: AL-Ameri Wahbi Abdulqader , Abdulraheem Abdulazeez , Mahmoud Mohamed , Abdullatif Osman , Adebayo Abdulrauf Rasheed
Published: December 2014

Geological sequestration of carbon dioxide (CO2) in underground formations is the most promising way to decrease the greenhouse emissions into atmosphere. The understanding of long term effects of CO2 storage in carbonate aquifers is challenged by many uncertainties including geochemical effects of CO2 on carbonates and the coupled chemical–mechanical effects. The carbon dioxide dissolves in water forming bicarbonate which will dissociate to carbonic acid. This acid dissolves calcites in carbonate rocks. As a result, the mechanical properties of the aquifer changes through this interaction. It is therefore necessary to study the effect of carbon dioxide sequestration on the integrity of a given formation to get safe and effective long-term storage of CO2 sequestration in deep saline aquifers. To the best of our knowledge, previous works on CO2 sequestration have focused on the impact of CO2 injection on the petrophysical and mechanical properties of formation rocks but the injection occurred in a short period, which was not enough for carbon dioxide to react with formation brine and thus the chemical reaction that will impact the properties of the rocks.

The main objective of this paper is to investigate the effect of CO2 storage on the mechanical properties of carbonate aquifer rocks that were exposed to soaking with CO2. Furthermore, the effect of the duration of CO2-brine contact time or solubility time on these properties was investigated. CO2 was stored in the cores at 2000 psi and 100°C for different time periods ranging from two weeks to three months. The cores were then analyzed for the mechanical properties using acoustics, unconfined compression, and indirect tensile strength testing machines.

Results showed that storing CO2 for longer times changed the rock mechanical properties significantly. Samples in which CO2 was stored for longer times exhibited greater change in mechanical properties compared to those in which CO2 was stored for shorter time. The geochemical interaction between CO2, brine, and rock is time dependent making changes in rock mechanical properties also time dependent.
First Successful Hydraulic Fracturing in the Offshore Abu Dhabi: Part1—Flexible Design to Unlock a Tight Gas with Uncertainties—
Authors: Kuroda Shintaro , Kaneko Masayuki , Al Ameri Fahed , Al Zarouni Asim , Al Zaabi Mohamed R. , Al Awadi Farhaad Khaled , Sabri Abdul Moez
Published: December 2014

The hydraulic fracturing technology is widely applied in tight reservoirs, including shale reservoirs, as one of the established reservoir stimulation methodologies to enhance the productivity. Even though the hydraulic fracturing is currently a common technique, there are remaining challenges in offshore fields with the high degree of geological and geomechanical uncertainties. In offshore hydraulic fracturing operations, key issues are the limited deck space for the required equipment on-board and economical aspects of the surface equipment including stimulation vessels due to the limited number of dedicated offshore stimulation vessels in the world. In addition, the limited reservoir information brings uncertainties in the hydraulic fracture design and causes difficulties in finalizing the operation plans from the timing and logistics point of view.

This paper contains the first part of the two successive parts of a case study will be shown on successful optimization and productivity enhancement of actual offshore hydraulic fracturing for a deep tight gas reservoir with considerably limited formation data and under a high-pressure and high-temperature (HP/HT) environment. This successful operation was recognized as a landmark in this region, in terms of the first hydraulic fracturing operation in the offshore Abu Dhabi.

In this paper (part 1), we describe how the flexible hydraulic fracture design led to an efficient productivity enhancement. The hydraulic fracture design was optimized by the integrated data acquisition strategy and the successive flexible adjustment from the design stage at office to the actual main treatment at wellsite. The relevant fracture design components like proppant usage and size can be optimized, based on sensitivity studies assuming not only all possible geological and geomechanical circumstances but also the actual pre-frac well test and data-frac results. In part 2, the key factors will be highlighted on this successful hydraulic fracturing result against the difficulties from operational point of view (Al Ameri et al. 2014).

The work flow and successful strategy in our hydraulic fracturing design and execution can be applied to other offshore tight-sand gas reservoirs including those under HP/HT condition. The optimized design of hydraulic fracturing provides an effective operation and enables more economical field development for the tight reservoirs.
Review of Downhole Wireless Communication Techniques
Authors: Arsalan Muhammad , Ahmad Talha J. , Noui-Mehidi Mohamed N.
Published: December 2014

Real-time permanent monitoring and control is essential to maximize production from oil and gas wells. An interdisciplinary approach is needed for any cost-effective solution that can perform and be sustained in the harsh downhole environment. For open hole horizontal wells, providing power and data through an umbilical is very challenging. Wireless communication is the essential component of any downhole monitoring and control solution in this situation. A wireless solution can also significantly reduce the complexity and cost associated with the wired solutions. In this paper various wireless communication techniques are classified and an extensive review of state-of-the-art downhole applications is presented. Advantages and limitations of each technique are discussed and recommendations are made of possible solutions.
Performance Evaluation of High Temperature Fracturing Fluid
Authors: Prakash Chetan , Achalpurkar Manoj P. , Uppuluri Ramesh
Published: December 2014

Hydraulic fracturing has remained a fundamental technique for stimulation of oil and gas reservoirs for enhanced or economic recovery of hydrocarbons from tight formations. Transporting proppant downhole without any interruption and maximum recovery of fracturing fluids are two important criteria for successful hydraulic fracturing. To achieve such objectives, the fracturing fluid should demonstrate good viscosity and complete cleanup of gelling agents. As wells are exploited at greater depths in environments of higher temperature and pressure, fracturing fluid selection is key. Fracturing fluids prepared by crosslinking guar, guar derivatives, and other naturally occurring polymers with borate or metal crosslinkers often exhibit instability at very high temperatures. The key reason for instability of the fracturing fluid is because strength of the bonds between the polymer chain and crosslinker decreases sharply in addition to breakdown of the glycosidic bonds between monomer units of the polymer chain beyond 375°F. Additionally, metal crosslinked bonds are prone to shear degradation, creating doubt for a successful job in high temperature long reach wells.

To address these issues, a synthetic gelling-agent-based fracturing fluid that can work at temperatures greater than 400°F was developed. The gelling agent is a terpolymer, which can be crosslinked with a zirconium-based crosslinker. This paper discusses evaluation and performance of an extreme temperature fracturing fluid. This fracturing fluid system has sufficient proppant carrying viscosity and provides efficient cleanup using delayed oxidized breaker. Analysis of fluid stability and delayed oxidizing breaker usage is presented in addition to performance parameters, such as regained permeability and fluid loss. The study illustrates performance of the synthetic gelling-agent-based fracturing fluid at temperatures ranging from 380 to 420°F.
Delivering an Integrated Real Time Data Environment for Wells and Facilities Offshore Abu Dhabi
Authors: Kirkman Matthew , Said Ahmed A. , Said Saad , Jama Ali Ahmed , Didanloo Ali , Rivadeneira Marcello , Ettireddi Srinivas
Published: December 2014

ADMA-OPCO is currently pursuing the development of several undeveloped structures offshore Abu Dhabi. in addition to the two giant fields that have been on production for many years. At ADIPEC in 2010, ADMA outlined plans for real time well surveillance offshore. This paper describes the implementation of the first phase of these plans for three existing facilities, one of the new fields, and HQ. This paper presents some of the details of that implementation and the opportunities this creates for improved well management.

The paper covers: Hardware architecture and designSoftware philosophy and integration with existing capability at ADMA OPCOAreas of business value incremental to prior practicesWorkflows and visualization of key well and facility data

The challenges ADMA-OPCO faces offshore Abu Dhabi dealing with a high number of complex wells, are to ensure adequate drainage and optimum flux rates, to enhance overall recoveries, from reservoir intervals in both existing, and more complex new fields. Real time well and facility data, transformed with the addition of both modelling capability and workflows, can translate into automation of some key processes and the addition of value by guiding scarce engineer time into the areas requiring the most attention. With ADMA OPCO's activity growth, the well to engineer ratio is increasing. To enhance organizational efficiency, ADMA will be able to automate some previously manual tasks by implementation of automated workflows.

A phased approach to the introduction of real time data in an evolutionary, rather than revolutionary approach, preserving and augmenting the functionality of existing tools enables the implementation to follow the pace of introduction of additional control and surveillance capability into the Brownfield environment.
Determination of Leading and Lagging Indicators Utilizing the BowTie Methodology
Authors: Groot Arthur , Bekker Nicola
Published: December 2014

Process Hazard Assessments is a recognized tool for assessing process design and production operations around the world. However, the methodology utilized to assess hazards range from standard HAZID, HAZOP and SIL workshops to complex consequence models (computational fluid models). In most cases the workshops can be based on the number and experience of the professionals present and the level of detail and time allowed for the assessment. Process Hazard Assessments also tend to concentrate on risks typically encountered in the design phase and not the total life cycle of the asset.

The BowTie methodology offers a structured approach for assessing how well all initial threats are being controlled and how prepared an organization is to mitigate consequences should things go wrong. It highlights the direct link between (preventive and corrective) controls and management systems, which include operational management systems, Health, Safety and Environment management systems, and asset integrity management systems.

The BowTie methodology has to date not been widely utilized in the determination of leading and lagging Key Performance Indicators for the operational risk management systems, despite the availability of this methodology for several decades. To encourage using the methodology, an approach has been developed to determine the leading and lagging Key Performance Indicators utilizing BowTie's. This paper reviews this process and presents different experiences and lessons learned from applying the method within (petro)chemical and pipeline companies. Based on the results, recommendations are made and conclusions drawn about how the BowTie method can best be adapted for determining leading as well as lagging Key Performance Indicators.
H2S Measurement Using Wireless Technology
Authors: Phelan P. , Khouri A-R Shames , Wahed H. A.
Published: December 2014

Description

H2S represents a major hazard encountered in Oil and Gas production and the efficient and reliable detection of gas leaks is a critical safety aspect of this business. Wireless detection systems offer an opportunity to expand the measurement area however this must be achieved reliably.

Wireless technology has developed rapidly in the consumer market for mobile phone and computing applications. Development in the onshore Oil and Gas industry has been less rapid due primarily to the conservative nature of the industry and the need to ensure reliability, particularly for new technology applied to safety related functions.

This paper will review a specific application installed at GASCO Asab facilities of wireless technology in gas detection. The paper will detail the steps taken to assess the integrity of the wireless system and the considerations necessary to ensure the reliability and availability of the signal transmission.

Applications

Although this example applied specifically to H2S measurement in the environment it is an approach which is applicable to gas detection and measurement transmission for many applications. It therefore has wide application potential throughout Oil and Gas production.

Results and Conclusions

The technology of wireless communication can provide significant opportunities for performance enhancement in the Oil and Gas Industry. It is however imperative to systematically consider and document issues which may affect reliability and availability. Some of the key limitations in terms of reliability, coverage range, statutory compliance and maintainability are addressed in this paper.

Technical contributions
Integrated Project Delivery (IPD): A Paradigm Shift for Oil & Gas Giga Projects
Authors: Al Subaih A. S.
Published: December 2014

The nearly $100 billion in megaprojects planned for Mozambique, for example, is more than 400 percent of the country's total GDP, and the planned oil and gas investments in Papua New Guinea are 123 percent of GDP. Even in large, developed conomies, the size and scale of new oil and gas investments can represent a significant portion of the total economy. The combined value of Australia's new oil and gas projects represents nearly 20 percent of the country's $1.5 trillion GDP for 2012. The economic benefits to the country of getting the projects right are enormous(Deloitte, 2013).

Consumption and Production increased for Oil & natural Gas to record levels across the globe. As per the BP Statistical Review of World Energy issued in June 2014, of the total world energy consumption, a staggering 57% is from Oil & Natural Gas. The world oil Consumption has increased by 9.96% and the world oil Production has increased by 7.1% since 2004. Of the total 86.8 Million Barrels of Oil Produced per (BOPD) 32.6% is produced by Middle East and 4.2 % by UAE alone. Similarly of the total 326 Billion cubic feet per day (BCFD) natural gas produced worldwide 16.8% is produced from Middle East of which UAE produced 1.7% (BP, 2014).

In its World Energy Investment Outlook 2014, the International Energy Agency (IEA) estimates a cumulative investment of US$22.4t in the global oil and gas sector between 2014 and 2035, equivalent to an average annual spend of more than US$1t. Middle East is expected to invest around US$ 206b between the period 2014 and 2035. The IEA expects oil and gas spending to increase sharply, increasing by almost 50% from its average of US$678b per year over the 2000–2013 period (EY, 2014). Figure 1.1 shows the Regional cumulative Oil & Gas ivestments between 2014 and 2035.