bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation Of The Stability Of Hollow Glass Spheres In Drilling Fluids In Diverse pH Environments And Assessment Of Potential Field Applications In Saudi Arabia
Authors: Alawami Mohammed B. , Al-Yami Abdullah S. , Wagle Vikrant B. , Alhareth Nasser
Published: September 2015

Low-density water-based drilling fluids formulated with hollow glass spheres (HGS) offer an attractive drilling method. HGS are incompressible lightweight additives with the capability to reduce mud weight down to 41.0 lbm/ft3 (5.5 lbm/gal). Several pressure ratings of HGS are available, and selecting the appropriate rating is essential to avoid formation damage and lost circulation in near-balance conditions. Failure of the spheres could thus lead to catastrophic results.

The objectives of this paper is to evaluate the stability of inhibited water-based drilling fluids formulated with HGS in diverse pH environments, and assess their potential application in Wasia formations in Saudi Arabia. Wasia formation is composed of middle cretaceous clastic rocks with layers of sandstone, shale and occasional limestone. Wasia is an aquifer with a thick unit that crops out in central Najd with a slight eastward dip (Powers et al. 1966). The pressures of Wasia correlate to equivalent mud weights (EMW) of 51—58 lbm/ft3. This range of EMW is lower than that of water, and the use of conventional mud systems could introduce several operational difficulties due to the high hydrostatic pressure they create. The implementation of HGS-based lightweight fluids would lower the hydrostatic pressure in the wellbore, thus eliminating or reducing the frequent loss of circulation experienced in Wasia. HGS-based fluids could also provide greater protection of underground water resources, improve rate of penetration (ROP), and reduce or eliminate differential pipe sticking.

We conducted comprehensive analysis of HGS performance in various pH environments to assess their stability in drilling fluids. Mud characteristics and rheological properties were examined before hot rolling (BHR) and after hot rolling (AHR) to determine the effects of high pressure and high temperature (HPHT) on the system. The duration at which the samples were exposed to HPHT conditions varied from 1 to 4 days to understand the behavior of the mud over time. In addition, two typical formulations were prepared using HGS and conventional additives to evaluate their properties and compare them to the American Petroleum Institute (API) standards.

Hollow glass microspheres were found to be stable in the pH conditions of drilling operations (pH ~9), with a maximum density variation of 0.5 lbm/ft3. At higher pH levels (pH >11), the spheres experienced fractional dissolution due to the reaction of the added NaOH with borosilicate glass. In pH ranges lower than 4, the spheres were found to be extremely stable. The inhibited water-based fluids formulated with HGS produced favorable rheology and stable mud characteristics before and after exposure to the actual downhole temperatures of Wasia formation.
An Integrated Approach to Acquire Formation Fluid Samples in a Challenging Low Perm Carbonate Reservoir Using an Oval-Shaped Pad: Western Desert, Egypt, Case Study
Authors: Kohail Mohammad , Fattah Mohsen Abdel , Helba Adly , Sayed Ahmed M. , Mohamed Hesham Saeid
Published: September 2015

Thinly laminated, low permeability carbonate rocks of the Turonian Abu Roash “D” (ARD) member, located in the north Western Desert of Egypt, provide a challenging environment for recording formation pressures and acquiring clean formation fluid samples. The challenges are partly attributable to reservoir lithological heterogeneity and low permeability in addition to the microporosity pore system. From the operations perspective, locating the probe on the sweet spot, and the difficulty associated with sealing probes on testing tools present major challenges.

To increase the success rate of obtaining valid pressure measurements and fluid samples, a proper selection of the formation tester probe geometry is essential. A series of prejob simulations using various probe types indicated that the use of oval-shaped pads provided distinctive advantages over standard probe types.

This paper includes field examples from the Abu Roash D carbonate reservoir where the oval-shaped pad was used. The wireline microresistivity imager was used to characterize the zone of interest and facilitate the test point selection.

The use of the image log for the pressure point selection in a thinly laminated reservoir and the oval-shaped pad positioned to cover a vertical section of the wellbore enabled the detection of a relatively permeable thin lamination with a mobility of 28 md/cp. This process facilitated the collection of a formation fluid sample for the first time from this reservoir after pumping for more than 1½ hours. A high resolution fluid density sensor was used for fluid identification, which was able to detect low concentrations of residual oil during sampling, unlocking, and eliminating the ambiguity in the understanding of the residual fluid in the Abu Roash D reservoir.

This paper presents the method, selection criteria, and workflow used to acquire formation fluid samples in challenging, low permeable carbonate reservoirs.
Commoditization of Natural Gas, Challenges and Prospects
Authors: Nassar Yehya M.
Published: September 2015

Thanks to its relatively friendly impact on the environment, natural gas usage has evolved to the point that puts forward natural gas as one of the main energy sources worldwide. Aside from the fact that natural gas is widely spreading all over the world and that securing natural gas supply has become a matter of great concern to all energy market players, natural gas still suffers from significant price variations and long-term supply dependency, which results in limited competition, less flexibility and reduced diversity of supply.

In particularly compared to liquid fuels, natural gas lacks certain features required for commoditization. These features are found in the so called “perfect competition” market structure and include among others, standardization or inconsiderable differentiation of the sold product, neglected price margin, diversity of supply, increased cost and hence price stability, availability, and obtainability. In general, product commoditization shall result in a number of benefits not only for the end users, but as well for all involved players along the whole processing value chain.

The aim of this paper is to investigate whether or not natural gas can be classified as a commodity and the forces that are currently affecting this commoditization process.

In doing that the paper will study the effect of natural gas transportation infrastructure costs, long term versus spot market contracts, storage methodologies, LNG compared to natural gas from a commoditization perspective and security of supply requirements. The paper will also discuss the reasons for the increased natural gas price differences worldwide. Finally, it will highlight some of the existing eco-political forces that might affect the pace of natural gas commoditization taking into account the effect of subsidy and trade barriers in certain regional markets on the commoditization process.
Delineation of Paleozoic Tecto-stratigraphic Complexities in the Northern Part of Murzuq Basin - Southwest Libya
Authors: Najem Ali , El-Arnauti Ali , Bosnina Seraj
Published: September 2015

Murzuq Basin is an intractratonic sag basin located in the southwestern part of Libya and considered as one of the major profitable basins in North Africa. The basin has been developed during the Late Precambrian-Early Paleozoic time, which went through various reactivated tectonic events. These events were dominant during the Paleozoic era coincided with regional unconformities and major sea level changes that resulted in complex geological configuration of both structural and stratigraphic. Detailed subsurface analysis implemented utilizing seismic and well log dataset of the concession NC186 to evaluate the main Paleozoic tecto-stratigraphic complexities within the northern part of the basin. This analysis guided to understand the major Paleozoic polyphase tectonic evolution in the area of study. Steep reverse basement faults, folds, positive flower structures and paleohighs and paleolows of glacial topography are evidently indication of the observed large-scale tectonic Paleozoic elements. From this study, the basement faults are anticipated to be genetically related to the Pan African Orogeny in origin and played major controller of all Paleozoic events. These faults are striking NW-SE with a vertical throw up to 300 meters and an oblique fault plane. Late Ordovician glacial valleys encountered in the area with more than seven kilometers of wide, which have eroded more than 500 meters of Middle Ordovician and Cambrian deposits. The incised valleys took place along the strike of the major basement faults in the area. The entire large-scale analyzed elements interpreted to be generated, directly and indirectly, by different tectonic regimes (i.e. compressional, extensional, strike-slip and combination) exclusively during Paleozoic time. Therefore, from the detailed interpretation; six phases are introduced as the main representative tectonic episodes of in the northern part of Murzuq Basin. These tectonic phases and episodes have controlled the petroleum system in the basin and the area of study in particular.
Monte Carlo Model Development for Elemental Analysis Using a Natural Gamma Ray Spectroscopy Tool
Authors: Zhang Qiong , Mendez Freddy , Longo John , Gade Sandeep , Bliven Steve
Published: September 2015

A systematic computational method for obtaining accurate elemental standards efficiently for varying borehole conditions was developed based on Monte Carlo simulations and computational data assimilation. Elemental standards are essential for spectral unfolding in formation evaluation applications commonly used for nuclear well logging tools. Typically, elemental standards are obtained by standardized measurements, but these experiments are expensive and lack the flexibility to address different logging conditions. In contrast, computer-based Monte Carlo simulations provide an accurate and more flexible approach to obtaining elemental standards for formation evaluation. The presented computational method recognizes that in contrast to typical neutron-photon simulations, where the source is typically artificial and well characterized [Galford, 2009], an accurate knowledge of the source is essential for matching the obtained Monte Carlo elemental standards with their experimental counterparts. Therefore, source distributions are adjusted to minimize the least square difference of the Monte Carlo computed and experimental standards. In this work, a natural gamma ray spectroscopy tool is selected as an example and the procedure of obtaining elemental standards through Monte Carlo modelling and data assimilation is demonstrated. A field case study is presented to compare two sets of elemental standards. For future work, the adjusted source distributions will be utilized to generate and validate spectra for varying borehole conditions: tool position, casing and cement thickness and the effect of these conditions on the spectra will be investigated. Given that Monte Carlo modeling provides much lower cost and more flexibility, employing Monte Carlo could enhance the processing of nuclear tool logging data computed standards.
An Essential Periodical Assessment & Performance Revision for Optimizing Sucker Rod Pumping Systems' Operations
Authors: Ali Mira , Mahmoud Rizk , Mahmoud Selim
Published: September 2015

West Qarun (WQ) and North Bahariya (NB) oil leases are being operated by Sahara Oil & Gas Company (SOG); the two leases are located in Abu El Gharadig (A/G) basin in the Egyptian Western Desert with a total of seven oil fields including a total of 58 producing wells “at the time of writing this paper”; According to the nature of silty-sand oil reservoirs in the area with low initial production rates; most of wells had been hydraulically fractured against one or more of the included various hydrocarbon bearing zones; this fact led to necessitating the deployment of an artificial lifting system that is capable of producing the expected initially high rates and then cope with the expected low rates after the routine initial decline in well rate.

According to theoretical sorting criteria and field trials; sucker rod pumping systems proved to be the most suitable artificial lifting system for these wells; but various wells conditions induced the use of several pumping parameters and equipment sizes according to each well conditions.

This paper demonstrates a methodology for initial sucker rod pumping system selection, wide scope for designing required equipment and operating parameters, and the essential periodical revision of pumping performance and assessment of the system within a continuous optimization process that aims to get maximum possible pumping rate and lowest operating costs via reducing the frequency of system failures and modifying operating parameters to the enhanced scheme as per well conditions.

The most difficult part in the evaluation process is obtaining accurate measurements in real time, integrate all available well data in diagnosing well pumping status, discover the tricky signs, and interact with well pumping parameters to reach the optimum status or decide a well intervention job.

The conclusion is summarized in attracting attention to the importance of ensuring the selection of optimum artificial lifting system to the field scale and then keep it operating with optimum design and operating parameters.
A Novel Approach to Achieve Zonal Isolation Objectives for Cementing the Longest 28-in. Surface Casing in Mediterranean Offshore Egypt
Authors: Fayed Mohamed Idris , Mehdiyev Akshin , Geldof Wilco , Bhaisora Devesh , Morsy Ahmed , El-Sawah Khaled
Published: September 2015

An operator spudded an extreme high-pressure/high-temperature (eHP/HT) well in the Mediterranean Sea, offshore Egypt, in 2012. To achieve the well objectives, it was necessary to set 28-in. surface casing at 1183 m, which was the deepest casing point used for such a large casing size in the offshore Mediterranean. The depth and size of the hole required presented numerous challenges, including but not limited to managing the variable deck load, hole stability during long casing running operations, logistic challenges for fluids resulting from significant washouts, etc.

One of the main challenges was related to achieving zonal isolation objectives for this section. These objectives were to cover the casing shoe with good quality cement and to achieve zonal isolation at the seabed and top of casing to help avoid future unexpected shallow flows to the surface. Meeting both of the objectives was paramount for resuming further operations. Typically, both of these objectives can be achieved in a single stage using lead and tail slurries. However, because of the long hole section and significant washouts (up to 300%), bringing cement up to the seabed would require pumping approximately 4,400 bbl of lead slurry and 380 bbl of tail slurry, which is equivalent to approximately 11,700 ft3 (500 MT) of dry cement, and 16 hr of cement pumping time.

To help mitigate the risks associated with a single-stage operation, it was decided to perform the job in two different stages. The first stage was designed to isolate the casing shoe and lower sand body by performing a lead and tail primary cement job. The second stage was a liner top squeeze. This was a multistage operation using several cement types of various particle sizes. The top of the liner was successfully squeezed, and the objectives of the cementing operation were met.

This paper describes the challenges experienced and solution for completing the cementing job, which could be valuable for designing similar offshore high-pressure/high-temperature (HP/HT) wells.
Non-Radioactive Detectable Proppant First Applications in Algeria for Hydraulic Fracturing Treatments Optimization
Authors: Forno Luca Dal , Latronico Roberto , Saldungaray Pedro , Petteruti Ernesto , Fragola Daniele , Allal Mohammed A. , Hachelaf Houari , Albani Danilo , Hamdane Toufik , Carpineta Gabriele
Published: September 2015

Bir Rebaa Nord (BRN) and Bir Sif Fatima (BSF) fields, operated by Groupement Sonatrach-Agip (GSA, a JV between ENI and Sonatrach), are located in the Berkine basin in north-eastern Algeria. These fields are characterized by oil-bearing sandstone reservoirs with low to medium petro-physical properties. During the development phase, to counteract the effect of pressure depletion, water and gas injection was implemented for reservoir pressure maintenance. In addition, due to the increasing water cut, artificial lift systems were employed to effectively produce these fields.

Hydraulic fracturing has been implemented in GSA since year 2000 to improve well performance, both in terms of productivity and injectivity for oil producers and water injectors respectively. The fracturing process has been improved over the years regarding operational procedures, enhanced reservoir knowledge and implementation of new technologies towards resolving the many uncovered challenges. Changes to the perforation strategy, fracturing fluids formulation, rock mechanics studies and design of proppant schedules are examples of enhancement to the fracturing practice that have been implemented in the recent years.

One of the uncharted matters in GSA, coming out from the post-job data re-processing, was the necessity of a precise characterization of the hydraulic fractures vertical coverage. The presence of several sandstone layers with different properties brought questions if the fracture had grown into an unwanted zone or may had not properly covered the entire target formation. Moreover, fracture height is an essential parameter for frac models calibration. Its accurate determination drastically reduces the margin of error in treatment net pressure matching, helping to more precisely established fracture half-length and width, stress profile and, last but not least, achieving a calibrated model for future operations in the same area.

This paper describes the successful implementation on two water injector wells of a novel non-radioactive detectable proppant for the first time in Algeria. The taggant material within the proppant has been located by comparing the pulsed neutron capture cased-hole logging passes registered before and after the hydraulic fracturing treatments. The detectable compound does not affect proppant properties and, in addition, its non-radioactive nature reduces the timing for materials delivery and eliminates the HSE risks linked to other tracing methods.

The pulsed neutron measurements evaluation provided valuable information regarding fractures confinement, avoidance of contact with undesired layers and possible presence of cement channeling. Furthermore, combined with sonic logs and cores data, it helped refining the geo-mechanical model for future interventions design in the same reservoirs.
Insights of Wellbore Imaging and Lithology & Mineralogy Wireline logs to minimize the Uncertainty Regarding Bit selection and Design, Engineering Approach
Authors: El Sherbeny Wael , Madkour Ali , Nuic Ivo , Richards Alun
Published: September 2015

Formation drillability is one of the most important aspects for planning and designing a new oil/gas well since the factors affecting the drilling performance have complex relationships between formation properties, drill bit design and operational parameters. In view of high operating cost of drilling rigs, if Rate of Penetration (ROP) can be enhanced, it will reduce open-hole formation exposure time and complications associated with it resulting in significant savings in drilling time and cost can be realized

Normally bit engineers utilize the assumed lithology from mud logs, detailed depth wise lithology of offset wells. The lithology can also be interpreted from conventional logging data such as Sonic, Gamma and Density. Furthermore, the rock's compressive strength is calculated using Compressional / Shear travel time (Sonic log), Bulk density (Density log) and Shale content (Gamma log).

These utilized tools to detect the lithology and rock mechanical properties have an extent of uncertainty due to effects either related to borehole or drilling fluids that require extensive corrections. That degree of uncertainty subsequently can affect the drill bit design criteria, selection and viability of performance-enhancing features.

This present paper reveals a new practical approach as a solution to minimize uncertainty in terms of bit design and selection by utilizing wellbore imaging and lithology & mineralogy wireline logs to precisely deliver an accurate input data to the drill bit design software modules.
Comprehensive Investigation of Effects of Nano-Fluid Mixtures to Enhance Oil Recovery
Authors: Tarek Mohamed , El-Banbi Ahmed H.
Published: September 2015

Using mixtures of metal oxides nano-particles suspended in water to form an injectable nano-fluid (rather than single nano-fluid) has been investigated. The use of mixtures nano-fluids proved its ability as an EOR agent and its advantages over single nano-fluids. This paper investigates the different parameters that affect the oil recovery when using nano-fluids mixtures to suggest an optimum scenario for applying this technique.

Four sandstone cores were used in the experiments. The first core was used to test effect of the dispersing fluid salinity on the oil recovery. A core was flooded three successive times, each time till oil production stopped completely, with the same mixture of nano-particles but dispersed in different brine concentration. It was concluded that dispersing fluid salinity has negligible effect on ultimate oil recovery.

The usage of nano-fluid injection after water flooding was tested on the second core. The core was water flooded with one pore volume followed by nano-fluid injection. The results of the experiments show the possible successful formation of an oil bank and sustaining oil production when nano-fluid mixture is used after waterflooding.

The third core was used to check the possibility of using a nano-fluid slug instead of continuous injection due to its economical advantage. The experiments proved the viability from recovery point of view and the advantages from an economic point of view of using slugs of nano-fluid mixtures rather than continuous injection of nano-fluids.

Finally, combining between low salinity technique and nano-fluid injection was tested in the fourth core. The experimental results show that combining low salinity and nano-fluid mixtures injection (in different slugs) can add additional reserves.
Automatic Reservoir Model Identification using Artificial Neural Networks in Pressure Transient Analysis
Authors: AlMaraghi Ahmad M. , El-Banbi Ahmed H.
Published: September 2015

Pressure transient well test analysis is commonly used to help characterize oil and gas reservoirs. In a typical well test, interpretation of rate/pressure data usually yield information about permeability, skin factor, boundary conditions, and character of the reservoir. Some well tests, however, suffer from ambiguity and non-unique interpretation. The objective of this study is to apply the Artificial Neural Network (ANN) technology to identify the reservoir model. A multilayer neural network, with back propagation optimization algorithm, is used to identify the reservoir model. The required training and test datasets were generated by using the analytical solutions of commonly used reservoir models. Nine ANN networks were constructed with each one capable of differentiating among six boundary models. Most commonly found reservoir models of different inner, outer boundary and reservoir medium are included (e.g. vertical, fractured and horizontal wells; homogenous, dual porosity and radial composite reservoirs; and infinite, one sealing fault, two sealing faults, rectangle and circle boundaries).

Each of the ANN of the nine networks has been constructed by one input layer, two hidden layers; and one output layer with six nodes characterizing the different reservoir boundary models. Different network structures and training intensity were tested during this work to arrive at optimum network design.

The performance of the proposed ANN was tested against simulated noisy and smooth datasets. The results indicate that the proposed multilayer neural network can recognize the reservoir models with acceptable accuracy even with complex models. The comprehensive testing of different ANN designs showed that success rate increases significantly by distributing the commonly used reservoir models into nine networks. This ANN design can still yield good results even with some noise in the pressure data. After testing the ANN, they were then used in the interpretation of several field cases (including complex tests) and results are presented in the paper.
Magnetic Flux Leakage (MFL) Technology Provides the Industry's Most Precise Pipe Integrity and Corrosion Evaluation, Accurately Characterizing Casing and Tubing Strength. Technology Overview and Case History
Authors: El Sherbeny Wael , Nuic Ivo , Hasan Gasser , Abdesslam Abba , Hassane Tharwat
Published: September 2015

The Magnetic Flux Leakage (MFL) Technique is the most commonly used technique to inspect large diameter transmission pipelines. A typical MFL inspection system uses permanent magnets to apply an axially oriented magnetic field to the ferromagnetic pipe material. The magnetic field is perturbed by a metal-loss region (usually caused by corrosion) to produce flux leakage outside the pipe, which can be measured by field sensors.

The magnetization system in an MFL inspection system should ideally produce a magnetic field that is strong enough to cause a measurable amount of magnetic flux to leak from the pipe material at metal-loss regions, uniform from inside to the outside surface of the wall thickness so that the measured signal is more linearly related to metal-loss depth, and consistent in magnitude along the length of a pipe so that flux leakage measurements can be compared at different locations during an inspection run.

In general, the field strength most strongly affects detection of metal loss defects while characterization of defect geometry requires a field that is strong, uniform, and consistent.

Improvements in the downhole hardware also provide more flexible and efficient data acquisition, reducing operating time while improving data accuracy and operational safety. In conventional magnetic flux leakage (MFL) tools, the flux leakage sensors are coils; in the “high-resolution” tool, the coil is replaced by multiple “Hall Effect” sensors.

The HR Vertilog service uses MFL measurements to identify and quantify internal and external corrosion defects. The overlapping arrays of flux-leakage sensors and discriminator sensors offer full circumferential inspection of the tubing or casing string. This process differentiates between metal-loss (corrosion) and metal-gain (hardware) Features, and distinguishes between general corrosion and isolated pitting. Paper represents technology overview and field cases history
EOS Tuning – Comparison between Several Valid Approaches and New Recommendations
Authors: Ali Mahmoud T. , El-Banbi Ahmed H.
Published: September 2015

Gas condensates and volatile oil reservoirs are simulated using compositional simulation or modified black-oil (MBO) approaches to account for composition changes in the reservoir1. The current approach in the industry is to use a tuned EOS model to represent the fluid phase behavior and volumetric properties. However; there is no consensus on how to tune an EOS model, how many pseudo-components to use, or what weight factors to apply to experimental data when tuning an EOS model for use in compositional and MBO reservoir simulation studies.

Regarding the EOS tuning parameters, for example, some investigators prefer to regress on the binary interaction parameters (BIP) and the (Ω's) parameters of the EOS. Others have chosen the volume shift, BIP's, and critical parameters as matching parameters. Also, there is a newer approach where some investigators have chosen to vary the plus fraction molecular weight followed by the volume shift parameters.

In this study, we have constructed an EOS model program to perform the five commonly used tuning approaches. We have investigated the different tuning approaches using a large data base of PVT samples spanning the range of black-oils through volatile oils and gas condensates (including rich gas condensates and lean wet gases). We have compared the different tuning approaches based on two criteria: (1) the quality of match after applying the tuning procedure, as indicated by the absolute average error (AAE), and (2) the percentage deviation in the tuning parameters from their original values.

The tuning of many reservoir fluids using the different approaches has shown that some approaches were more superior to others and usually yielded excellent matches. While the other tuning approaches gave moderate to good matches. Based on this work, we were also able to give practical recommendations on tuning approaches that yield consistent EOS models.
Fullfield EOR Design for One Oilfield
Authors: Pang Wei , Zhang Tongyi , Deng Dawei , Du Juan , Sun Mingguang
Published: September 2015

Girasol oilfield is the first oilfield of Mansarovar Energy Colombia Ltd. (MECL) employing horizontal wells. With first well drilled in 2004 and commercial development started in 2008, this typical heavy oilfield have been produced for 10 years, but the current recovery factor is only 5.09%, and that is much lower than that of similar oilfields.

Girasol oilfield is at the medium stage of the cyclic steam stimulation (CSS) with 5.3 cycles and remaining reserves of 40.54 MMbbl. Based on characteristics of typical mid-shallow inter-bedded reservoirs with heavy oil in Girasol oilfield, by applying methodology of reservoir engineering and numerical reservoir simulation, the development status of Girasol oilfield is analyzed through full utilization of the geologic, logging and production performance data, and etc. Five potentials for production enhancement are researched including (1) Potential for well pattern improvement: except layer A12 and A9-Upper, other layers exist 30%∼70% of uncontrolled regions in transition part between vertical and horizontal wells, near-boundary, low permeability areas; (2) Potential for well infilling: the well spacing is about 150m, while heating radius is about 50m, so there exist oils hard to exploit between wells. Numerical simulation shows the average heating area is only 33.07%. (3) Potential for CSS parameter optimization: compared with other similar blocks, the steam injection parameter is unoptimized, and there is a good potential for steam injection parameters adjustment; (4) Potential for horizontal lateral optimization: the current horizontal lateral of 600m on average is too long for thermal production because it will leads to high heat loss, un-uniform steam adsorption and poor steam injection effect; (5) Potential for steam flooding.

Aiming at the development potentials of Girasol oilfield, Sector models based on numerical simulation are carried out to optimize thermal mode, well pattern type, well spacing, injection-production parameters and horizontal lateral length for vertical wells and horizontal wells separately. Full field EOR conceptual designs are conducted and 7 development schemes are simulated.

Results show increasing periodic steam injection amount for CSS to 2 times can get much better production performance; the optimized horizontal well lateral length is 300-400 meters. Steam flooding is a very promising EOR method for Girasol oilfield and it can lead to 43.73% of recovery under current well pattern to year 2030; it can get 45% more oils by only adjusting CSS injection parameters and improving well pattern with 12 new wells, so it's recomended under current production period.

This paper constructs a framework and technical route for fullfield EOR enhancement design of heavy oil reservoir from potential analysis, sector simulation to fullfield scale implementation.
Correlation between seedling length and Canadian Douglas-fir height
Authors: Lavadinovic Vera , Lavadinovic Vukan , Poduska Zoran , Djordjevic Ilija
Published: September 2015

This paper presents the results of the studies of Douglas-fir seeds from
Canada aimed at understanding and controlling the processes of the genetic
growth potential of Douglas-fir in Serbia. The research was focused on the
early stage of Douglas-fir growth, i.e. at the stage of seed germination in
the laboratory. We tested the correlation between seed germination, seedling
length and the height of plants in the nursery. The seeds from 13 Douglas-fir
(Pseudotsuga menziesii (Mirb.) Franco) localities were obtained from Canada
and compared under laboratory and nursery conditions. The seeds from
different altitudes, latitudes and longitudes come from a part of the natural
range of Douglas-fir in Canada. Before they are transferred and introduced,
seed material must be tested with regard to the potential success of the
selected tree species within the shortest possible time. This is necessary
for the introduction of a tree species with a widespread natural range.
Douglas-fir is a highly productive coniferous tree species with a broad
geographical and ecological range. It has a wider natural range than other
conifers and greater chances of successful adaptation to new ecosystems.
Descriptive statistics, analysis of variance for regression, regression and
correlation were used to analyse the data. A strong correlation was
established between the height of four-year-old seedlings and seed
characteristics (germination rate and seedling length).
Effects of fixed labial orthodontic appliances on speech sound production
Authors: Paley Jonathan S. , Cisneros George J. , Nicolay Olivier F. , LeBlanc Etoile M.
Published: September 2015

Objective: 

To explore the impact of fixed labial orthodontic appliances on speech sound production.

Materials and Methods: 

Speech evaluations were performed on 23 patients with fixed labial appliances. Evaluations were performed immediately prior to appliance insertion, immediately following insertion, and 1 and 2 months post insertion. Baseline dental/skeletal variables were correlated with the ability to accommodate the presence of the appliances.

Results: 

Appliance effects were variable: 44% of the subjects were unaffected, 39% were temporarily affected but adapted within 2 months, and 17% of patients showed persistent sound errors at 2 months. Resolution of acquired sound errors was noted by 8 months post–appliance removal. Maladaptation to appliances was correlated to severity of malocclusion as determined by the Grainger’s Treatment Priority Index. Sibilant sounds, most notably /s/, were affected most often.

Conclusions: 

(1) Insertion of fixed labial appliances has an effect on speech sound production. (2) Sibilant and stopped sounds are affected, with /s/ being affected most often. (3) Accommodation to fixed appliances depends on the severity of malocclusion.
Identification of Bile Duct Paucity in Alagille Syndrome: Using CK7 and EMA Immunohistochemistry as a Reliable Panel for Accurate Diagnosis
Authors: Herman Haley K. , Abramowsky Carlos R. , Caltharp Shelley , Metry Diana , Cundiff Caitlin A. , Romero Rene , Gillespie Scott E. , Shehata Bahig M.
Published: September 2015

Bile duct paucity is the absence or marked reduction in the number of interlobular bile ducts (ILBD) within portal tracts. Its syndromic variant, Alagille syndrome (ALGS), is a multisystem disorder with effects on the liver, cardiovascular system, skeleton, face, and eyes. It is inherited as an autosomal dominant trait due to defects in NOTCH signaling pathway. ALGS is characterized by vanishing ILBD with subsequent chronic obstructive cholestasis in approximately 89% of cases. Cholestasis stimulates formation of new bile ductules through a process of neoductular reaction, making it difficult to evaluate the presence or absence of ILBD. Therefore, finding a method to differentiate clearly between ILBD and the ductular proliferation is essential for accurate diagnosis.

A database search identified 28 patients with confirmed diagnosis of ALGS between 1992 and 2014. Additionally, 7 controls were used. A panel of two immunostains, cytokeratin 7 (CK7) and epithelial membrane antigen (EMA), was performed.

CK7 highlighted the bile duct epithelium of ILBD and ductular proliferation, while EMA stained only the brush border of ILBD. In our ALGS group, the ratio of EMA-positive ILBD to identified portal tracts was 12.6% (range, 0%–41%). However, this same ratio was 95.0% (range, 90%–100%) among control cases ( P < 0.001).

We propose a panel of two immunostains, CK7 and EMA, to differentiate ILBD from ductular proliferation in patients with cholestasis. With this panel, identification of bile duct paucity can be achieved. Additional studies, including molecular confirmation and clinical correlation, would provide a definitive diagnosis of ALGS.
Enterovirus D68 and Panton-Valentine Leukocidin–Positive Staphylococcus Aureus Respiratory Coinfection with Fatal Outcome
Authors: Ravishankar Sanjita , Chapin Kimberle , Alexander-Scott Nicole , Wills Hale , Merritt Christopher , Jacobson Melanie , Kleris Renee , Alhinai Zaid , Sediva Ivona , Muratore Christopher , Mermel Leonard , Mangray Shamlal
Published: September 2015

A previously healthy 10-year-old girl with a 2-day history of upper respiratory illness and fever rapidly developed respiratory failure and sepsis with leukopenia, and expired despite attempts at resuscitation. Postmortem examination revealed bilateral necrotizing pneumonia and evidence of disseminated intravascular coagulation. Nasopharyngeal swabs and lung tissue submitted to the Centers for Disease Control and Prevention (CDC) were positive for Enterovirus D68 (EV-D68). Blood and lung cultures were positive for methicillin-resistant Staphylococcus aureus (MRSA). The isolates were submitted to the CDC and were found to be positive for the toxin Panton-Valentine leukocidin. We describe a fatality related to invasive toxin-mediated MRSA associated with EV-D68 coinfection, along with the clinical, laboratory, and autopsy findings, which provided important clues, prompting further investigation at the CDC to arrive at the correct diagnosis.
Tracheal Atresia with Segmental Esophageal Duplication: An Unusual Anatomic Arrangement
Authors: Gaerty Kirsten , Thomas Joseph T. , Petersen Scott , Tan Edwin , Kumar Sailesh , Gardener Glenn , Armes Jane
Published: September 2015

An unusual anatomic configuration of segmental tracheal agenesis/atresia with esophageal duplication on autopsy in a fetus that demised in utero at 29 weeks is reported. The mother was scanned initially for a cardiac anomaly at 20 weeks and on follow-up scan at 27 weeks had polyhydramnios and underwent amnioreduction. The final autopsy diagnosis was vertebral, ano-rectal, cardiac, tracheoesophageal, renal, and limb malformations (VACTERL). We discuss the autopsy findings along with the embryological mechanisms and compare the configuration with Floyd's classification for tracheal agenesis. The difficulties in prenatal diagnosis are discussed.
The Lattice Structure of Equally Extended Signed Partitions
Authors: Cattaneo Gianpiero , Chiaselotti Giampiero , Gentile Tommaso , Oliverio Paolo A.
Published: September 2015

Signed partitions are used in order to describe a new discrete dynamical model whose configurations have fixed sum and whose evolution rules act in balancing from left and right on the configurations of the system. The resulting model can be considered as an extension to the case of signed partitions of the discrete dynamical system introduced by Brylawski in his classical paper concerning the dominance order of integer partitions. We provide a possible interpretation of our model as a simplified description of p – n junction between two semiconductors. We also show as our model can be embedded in a specific Brylawski dynamical system by means of the introduction of a new evolution rule.
Drug Addiction Pattern and Knowledge on HIV/AIDS Among Male Addicted Undergoing Rehabilitation
Authors: Haque Md Monoarul , Bhuiyan Md Rijwan , Amin Md Ruhul , Islam Khaleda , Islam Md Shahinoor
Published: September 2015

Background: The purpose of this study was to assess drug addiction pattern and knowledge on HIV/AIDS among male addicted undergoing rehabilitation.Methodology: A cross sectional descriptive study was conducted among purposively selected 100 drug addictors in a selected hospital. Pretested semistructured questionnaire was used to collect data by face to face interview.Result: Mean age of respondents was 34.02+_7.12 years. Result showed that about 39.8% of the respondents were addicted due to their friends incitement. More than half (61%) of the drug addicts were taken both Heroin and Injection (narcotics). About 82% of the respondents were never sold blood and 18% were sold their blood due to addiction. More than half (58%) of the respondents were taken sex with residential & commercial sex workers and 27% were taken sex only with their wives. Only 15% had no sexual activity. And more than half (57%) of the respondents did not use condom and 36% were used condom occasionally during their sexual activity. Only 7% used condom regularly. Besides study found that more than 97% of the respondents had knowledge on HIV/AIDS. Only 3% never heard about HIV/AIDS. Result found that 81.4% of the respondents had knowledge on the severity of HIV/AIDS disease and 18.6% did not know. About 89.7% of the respondents said that they had knowledge on transmission of HIV/AIDS through needle sharing and 10.3% did not know. Majority of the respondents 75% had knowledge to prevent HIV/AIDS more than one reason whereas 15.2% showed other reasons.Conclusion: Further large scale study should be conducted and the study result should not be generisable.Anwer Khan Modern Medical College Journal Vol. 6, No. 1: January 2015, Pages 5-9
Sero-Prevalence of Anti HCV Among Blood Donors Attended at Transfusion Medicine Department of DMCH in 2013
Authors: Karim Shanaz , Hoque Ehteshamul , Begum Hussne Ara , Hoque Mazharul
Published: September 2015

Bacground: Post transfusion hepatitis through blood and blood product is still very high in our country. This present study was carried out to find out the prevalence of sero Positive of anti HCV among the blood donors attended at transfusion medicine department of DMCH in 2013 and also to prevent transmission of HCV infection through blood transfusion.Methodology: This cross sectional study was carried out at transfusion medicine department of DMCH from 1st January 2013 to 31st December 2013.Total blood donors were 27,560. Among total 31890 blood donors, relative donors were 25,773.and remaining 6,117 donors were voluntary donors. Blood donors of 18 - 60 years of both sexes were included in this study. Among 31,890 blood donors relative blood donors were 25,773(80.81%), voluntary blood donors were 6,117.(19.18%)Among 31,890 blood donors Anti HCV Sero positive were 33(0.1034%).Result: Among total blood donors male and female were 25,880 ( 81.15 % ) and 6010 (18.85 %) respectively. Age ranges of donors were 18 -40 years 28500 (86.23 % ) and 41 -60 years 3390 (10.63 %).Conclusion: Frequency of HCV seropositive among donors were 33 (.1034 %).Anwer Khan Modern Medical College Journal Vol. 6, No. 1: January 2015, Pages 25-27
From the Desk of Editor in Chief Vol.6(1)
Authors: Rahman Md Tahmnur
Published: September 2015

Abstract not availableAnwer Khan Modern Medical College Journal Vol. 6, No. 1: January 2015, Pages 58
Méritocratie et usages du redoublement dans les écoles primaires publiques de la Seine (Fin XIX e -début XX e siècle)
Authors: Krop Jérôme
Published: September 2015

À partir de la nomination d’Octave Gréard à la tête de l’enseignement primaire de la Seine en 1865, ce département devient le laboratoire de la modernisation de l’enseignement primaire, faisant des écoles de Paris et sa banlieue le berceau du modèle scolaire républicain. Or le passage progressif de l’enseignement mutuel à l’enseignement simultané dans les grands établissements scolaires urbains, parachevé par l’organisation pédagogique mise en œuvre en 1868 qui sera généralisée par les réformateurs des années 1880, conduit à un usage massif du redoublement, indissociable d’une idéologie méritocratique privilégiant la réussite des élèves réussissant le mieux leurs premiers apprentissages scolaires.
Buddy Up for Exergames
Authors: Ede Alison , Forlenza Samuel Thomas , Feltz Deborah L.
Published: September 2015

Many adults and children in the U.S. are not active enough to meet the U.S. Department of Health and Human Services guidelines for physical activity to maintain health and reduce the risk of chronic disease. Exergames (exercise video games) have the potential to promote physical activity, and researchers have examined ways for improving motivation to exercise for longer and at higher intensities with these types of games. This chapter considers group dynamics principles as one way to influence motivation within exergames to help realize better health outcomes. We illustrate how group dynamics principles can be applied to exergames and how different task structures within groups (e.g., conjunctive, additive, and coactive tasks) can influence motivation. One group dynamic principle, the Köhler motivation gain effect, has been the basis of a series of research studies that we have conducted within exergames. We summarize this research, discuss the issues, controversies, and problems with using group dynamics in exergames, and provide possible solutions and recommendations.
Review of Serious Games for People with Diabetes
Authors: Makhlysheva Alexandra , Årsand Eirik , Hartvigsen Gunnar
Published: September 2015

This chapter aims to illuminate the current state of the field of diabetes-related serious games. First, it describes the problems and difficulties for young people with type 1 diabetes associated with their adherence to treatment regimens. The chapter also discusses various tendencies in the field of diabetes-related games that follow the findings of the systematic reviews performed between 2012 and 2014. Based on the reviews, significant gameplay features of games for health are identified. Further, it presents an example of a smartphone-based serious game developed for children with type 1 diabetes. Finally, this chapter discusses the distribution channel and platforms for serious games and improvements for the status of the field of games for health.
Del socio inglés a la asociación estratégica con China: Argentina y el realismo periférico
Authors: Bolinaga Luciano Damián
Published: September 2015

Desde la perspectiva teórica del realismo periférico se analiza la política comercial y exterior de los países periféricos en una coyuntura de cambio internacional. Así, el periodo 1989-2014 es relevante porque se produce el cambio del epicentro económico mundial hacia el Pacífico Norte y se acelera el ascenso de China como gran potencia. El caso argentino expone como un país periférico reorienta su política comercial y exterior hacia los nuevos centros de poder internacional. Asímismo, el factor estructural sale a la luz al estudiar las relaciones bilaterales de Argentina con Inglaterra, bajo el epicentro económico del Atlántico europeo, y con Estados Unidos, ya con el eje económico sobre el Atlántico Norte. El estudio de tendencias recurrentes del sistema resulta de un alto valor instrumental para el diseño e implementación políticas comerciales y exteriores. Argentina aprovechó su vínculo bilateral y la complementación comercial con Inglaterra. Frente al ascenso de Estados Unidos optó por confrontar y tuvo que lidiar con estructuras productivas competitivas. Ante la emergencia de China como una gran potencia cabe preguntarse qué tipo de vínculos comerciales y políticos mantuvo la Argentina con el país asiático.