bluuebunny/crossref_metadata_2025_split huggingface dataset:
Unlocking Additional Reserves Using Horizontal Wells with Multi Stage Fractures in the Western Desert of Egypt
Authors: AbdElNasser M. G. , Al-Maraghi A.M.. M. , Abady S. M. 
Published: October 2015

Abstract
This paper presents a case study for drilling a horizontal well with multi stage transverse fractures in the NEAMA field in Karma concession in the western desert of Egypt. The well production results are expected to lead the Western Desert operators to change the development strategy for several western desert fields to unlock the unrecovered reserves in the upper Baharia tight formation.
NEAMA field has total of 9 wells: 5 wells on production with total production around 500 BOPD, and 4 shut-in wells due to low productivity. The field STOIIP is around 15 MMSTB. With the historical low initial production rates, it was decided to develop the stranded reserves by drilling a horizontal well to replace three vertical wells and test the feasibility of applying horizontal wells with multi-stage fracturing in such tight reservoir.
A horizontal well with 7 fracturing stages was completed at the down-dip part of the field, LWD (Logging While Drilling) measurements were used to control well's direction and predict rock lithology. The LWD helped to control the well trajectory between the upper and lower boundaries of the reservoir's zone of interest. The well was completed with permanent downhole pressure gauge and ESP system in the vertical hole.
The well was put on production with initial rate of 400 BOPD with 20% water cut which was four times the total field production. The well production was maintained at low water cut until water production increased significantly. Integrated analysis of all collected data revealed that water channeling behind casing was responsible for the excessive water production. It was planned to work over the well to restore its oil production.
The paper discusses the integrated data analysis techniques that led to the choice of completion option of horizontal well with transverse fractures for new wells in NEAMA field. The results and additional analyses of both pressure and production data are expected to help other Western Desert operators to develop significant reserves of tight UBAH reservoir.
Field Development and Well Planning in Tight Carbonate Reservoir Using Fracture Characterization and In-Situ Stress Mapping From Core Reorientation Studies: Kuwait Case Study
Authors: Pattnaik Chinmaya , Rao Narhari Srinivasa , Al-Ashwak Samar , Al-Ajmi Neema Hussain , Kidambi Vijaya Kumar , Al Anzi Abdullah Motar , Dashti Qasem , Staffelbach C.. , Barbé Jean-françois 
Published: October 2015

Abstract
Fracture characterization is vital for efficient field development of naturally fractured Carbonate reservoirs. Successful development of fracture reservoir in the study area was possible due to early recognition of fracture play right from the exploration phase and through careful execution of relevant data acquisition campaign in the initial stages of field development. Comprehensive and integrated studies have been carried out over the past few years to arrive at an understanding of the conceptual model in deciphering structural evolution of North Kuwait Jurassic.
Extensive core and image log data was acquired in the initial stages of field appraisal, which helped in comprehensive forward planning in design of deviated and horizontal wells. The data analysis steps included accurate and reliable reorientation of the cores. These data were calibrated with the image logs, along with available seismic attributes, which resulted in better understanding of structural evolution and sweet spotting of horizontal wells. This reorientation of the core data also helped in establishing a number of quantitative fractures attributes such as frequency, spacing, dip-azimuth and aperture along with mapping of in-situ stress directions. The detailed integration of these data also helped in accurately mapping the local and regional present day stress and its variations spatially across the fields. Stress direction across the field was helpful for deciding the azimuth of wells during well planning along with selection of completion strategy for current set of horizontal drilling Campaign.
Drilling and testing results have been encouraging through enhanced reservoir performance in these tight carbonate reservoirs, based on these integrated studies.
Simultaneous Sorption and Mechanical Entrapment During Polymer Flow Through Porous Media
Authors: Farajzadeh R.. , Lotfollahi M.. , Bedrikovetsky P.. 
Published: October 2015

Abstract
Physical adsorption and mechanical entrapment are two major causes of polymer retention in porous media. Physical adsorption is believed to be an equilibrium process and is often modelled by assuming a Langmuir isotherm. The outcome is steady-state pressure response because the permeability reduction is also accounted for by adsorption. However, some experimental data show gradual increase of pressure with time implying that polymer retention is a kinetically-controlled process.
In this paper, we discuss simultaneous effect of sorption and mechanical retention on the polymer retention in porous media. An exact solution for 1-D flow problem for the case of constant filtration coefficient and Langmuir sorption isotherm, including explicit formulae for breakthrough concentration and pressure drop across the core is derived. The general model with varying filtration coefficient was successfully matched with coreflood data confirming the occurrence of simultaneous sorption with deep bed filtration.
In the absence of mechanical entrapment, the physical adsorption causes delay in the polymer front and does not affect the polymer concentration behind the front. Addition of mechanical entrapment results in very slow recovery of the injected concentration at the outlet (for varying filtration coefficient) or reaching to a steady-state concentration, which is only a fraction of the injected concentration (for a constant filtration coefficient). The results indicate that the accurate assessment of polymer retention requires both pressure and effluent concentration data at the outlet of the porous medium. In many cases, the kinetics involved in the mechanical entrapment could be very slow. In such cases, the experiments with few pore-volumes of injected polymer can be misleading and should not be directly used for field simulations.
Foam Stabilized by Fly-Ash Nanoparticles for Enhancing Oil Recovery
Authors: Eftekhari Ali Akbar , Krastev Rumen , Farajzadeh Rouhi 
Published: October 2015

AbstractFoam has been employed as an Improved/Enhanced oil recovery (IOR/EOR) method to overcome gravity override and the channeling and fingering of the injected gas, which arises due to the low density and viscosity of the injected fluid combined with the rock heterogeneity. A major challenge; however, is the stability of the generated foam when it contacts the oil. Foam boosters, which are generally costly surfactants, have been co-injected together with the main foaming surfactant to create stable foams in the presence oil. Similar to surfactants, particles can also accumulate at the gas-liquid and liquid-liquid interfaces. The difference is that the energy of adsorption and desorption of particles to the interface is so large that their adsorption is considered irreversible. Nanoparticles are orders of magnitude smaller than pore throats and therefore can easily flow through porous media.In this study we investigate the possibility of replacing the expensive foam boosters with inexpensive nanoparticles made of coal fly-ash, which is abundantly available as a by-product of coal power plants. We investigate the viability of reducing the size of fly-ash particles using high frequency ultrasonic grinding. We also study the foaminess (foamability) and stability of the foams made with minor concentrations of fly-ash nanoparticles and surfactant both in bulk and porous media. The effect of monovalent and divalent ion concentration on the foaminess of the nano-ash suspension combined with very low concentrations of a commercial alpha olefin sulfonate (AOS) surfactant, in presence and absence of oil, is studied.We observe that bulk foam that contains very small amounts of nano-ash particles shows a higher stability in presence of model oils. Furthermore, experiments in porous media exhibit remarkably stronger foam with mixtures of nano-ash and surfactant, such that the amount of produced liquids from the cores significantly increases. In presence of oil, the nano-ash-AOS foam shows a higher stability, although crude oil tends to form stable emulsions in water in presence of nano-ash.
Visualization of Oil Mobilization in ASP Core Floods Using X-ray CT Imaging
Authors: van Batenburg D. W. , Berg S.. , Oedai S.. , Elewaut K.. 
Published: October 2015

Abstract
This paper describes a series of experiments that used X-ray computer tomography (CT) to visualize the mobilization of remaining oil by Alkaline Surfactant (AS) and Alkaline Surfactant Polymer (ASP) flooding after conventional waterflooding. The experiments were conducted in cores drilled from Gildehauser and Bentheimer sandstone outcrop material with diameters of approximately 7.55 cm and lengths of approximately 27 cm and one meter. Crude oil with in-situ viscosities of 1.3, 2.3 and 100 cP was used in the experiments. The changes in the fluid saturation distributions with time obtained with X-ray computer tomography are subsequently used to improve the conceptual understanding of the ASP process.
In addition to pressure and effluent data collected during conventional core flood experiments, phase and saturation distributions in space and time are needed to more completely interpret the results of core floods. This additional information reveals underlying mechanisms, and assists the development of models that capture the physics of ASP that can ultimately be used to provide field scale predictions for ASP performance.
One important observation from the experiments is that there exist a consistent fingering pattern in the zone upstream of the oil bank. Although fingering is often considered a bad sign for a displacement process the experiments also demonstrate that the fingering zone is contained in the area upstream of the oil bank and that the velocity of the front of the oil bank is significantly greater than that of the fingering zone. The production following the clean oil bank (tail) observed in many ASP core floods is a consequence of the formation of this fingering zone.
Effluent analyses conducted on the produced fluids from the long core experiments showed a sharp, rapid build up in polymer viscosity that coincides with the beginning of the tail production while the surfactant concentration only gradually increases to its injection value during the tail production.
Another important observation is that a characteristic self-similar cross-sectional averaged oil saturation profile develops during ASP injection after water flood in cores containing reactive crude oil with 100 cP viscosity and in non reactive light crude oil.
The implications of the self-similarity of the saturation profiles in combination with the observation that the surfactant propagation is retarded with respect to the polymer propagation results in a polymer flood ahead of the ASP-slug and a corresponding characteristic oil production profile. The characteristics of this process can be captured with an extended fractional flow approach that utilizes three fractional flow curves: one for the ASP-slug, one for polymer, and the original fractional flow curve for oil-water.
Effects of Immediate Dentin Sealing and Pulpal Pressure on Resin Cement Bond Strength and Nanoleakage
Authors: Santana VB , de Alexandre RS , Rodrigues JA , Ely C , Reis AF 
Published: October 2015

SUMMARYObjective: The object of this study was to evaluate the simulated pulpal pressure (SPP) and immediate dentin sealing technique (IDS) effects on the microtensile bond strength (μTBS) and nanoleakage of interfaces produced by different luting agents.Methods and Materials: Two self-adhesive luting agents (RelyX Unicem [UC] and Clearfil SA Luting [SA]) and two conventional luting agents (Rely X ARC [RX] and Panavia F [PF]) were evaluated. Eighty human molars were divided in four groups according to luting agents. Each group was subdivided according to SPP (with or without) and dentin sealing (immediate or delayed) using Clearfil SE Bond (n=5). After IDS was performed, specimens were stored in water for seven days before luting procedures. Composite blocks were luted according to the manufacturers' instructions. One half of the specimens were subjected to 15 cm H2O of hydrostatic pressure for 24 hours before cementation procedures and continued for 24 hours afterward. Then, restored teeth were sectioned into beams and tested in tension. Two additional teeth per group were prepared for nanoleakage evaluation with scanning electron microscopy. Bond strength data were statistically analyzed by three-way analysis of variance and Tukey test.Results: μTBS of RX decreased when it was subjected to SPP without IDS. However, in the same conditions, μTBS of UC increased. The IDS prevented negative influence of SPP on μTBS of RX and PF; however, a decrease in μTBS of SA and UC was observed. Except for RX, IDS increased μTBS for all resin cements.Conclusion: Independent of SPP, the IDS technique obtained higher μTBS for PF, SA, and UC and did not influence RX μTBS.
Predictors of Outcome in Neonates with Respiratory Distress
Authors: John BM , Venkateshwar V , Dagar V 
Published: October 2015

Introduction: Many of the parameters utilised in scoring systems used to predict disease severity in respiratory distress in neonates are not readily available in the primary care facility of developing countries. This study was carried out to assess the utility of birth weight, gestational age, APGAR score at 5 min, baseline oxygen saturation and Downe’s score in prediction of requirement of respiratory support and mortality in neonates with respiratory distress.Material and Methods: A prospective study was carried out in the neonatal intensive care unit of a tertiary teaching hospital. 165 consecutively admitted neonates presenting with respiratory symptoms were included in the study. The relevant parameters and investigations were documented in a structured performa. The neonates were followed up for outcomes which included requirement of respiratory support and mortality.Results: A higher mortality was associated with birth weight of < 1620 grams, gestational age of < 31 weeks, APGAR score of < 6, Downe’s score of > 3 and baseline oxygen saturation of < 86 % (p values < 0.001). The requirement of mechanical ventilation was more with birth weight of < 2000 grams, gestational age of < 32 weeks, APGAR score of < 7, Downe’s score of > 4 and baseline oxygen saturation of < 87 % (p value < 0.001). The requirement of any respiratory support at 72 hours was associated with birth weight of < 1894 grams, gestational age of < 37 weeks, APGAR score of < 7, Downe’s score of > 3 and baseline oxygen saturation of < 89 % ( p-value <0.001).Conclusions: Readily available parameters like birth weight, gestational age, APGAR score, oxygen saturation and Downe’s score could together be used to predict mortality and requirement of respiratory support in the resource limited setting. J Nepal Paediatr Soc 2015;35(1):31-37
Face, content, and construct validity of human placenta as a haptic training tool in neurointerventional surgery
Authors: Ribeiro de Oliveira Marcelo Magaldi , Nicolato Arthur , Santos Marcilea , Godinho Joao Victor , Brito Rafael , Alvarenga Alexandre , Martins Ana Luiza Valle , Prosdocimi André , Trivelato Felipe Padovani , Sabbagh Abdulrahman J. , Reis Augusto Barbosa , Maestro Rolando Del 
Published: October 2015

OBJECT
The development of neurointerventional treatments of central nervous system disorders has resulted in the need for adequate training environments for novice interventionalists. Virtual simulators offer anatomical definition but lack adequate tactile feedback. Animal models, which provide more lifelike training, require an appropriate infrastructure base. The authors describe a training model for neurointerventional procedures using the human placenta (HP), which affords haptic training with significantly fewer resource requirements, and discuss its validation.

METHODS
Twelve HPs were prepared for simulated endovascular procedures. Training exercises performed by interventional neuroradiologists and novice fellows were placental angiography, stent placement, aneurysm coiling, and intravascular liquid embolic agent injection.

RESULTS
The endovascular training exercises proposed can be easily reproduced in the HP. Face, content, and construct validity were assessed by 6 neurointerventional radiologists and 6 novice fellows in interventional radiology.

CONCLUSIONS
The use of HP provides an inexpensive training model for the training of neurointerventionalists. Preliminary validation results show that this simulation model has face and content validity and has demonstrated construct validity for the interventions assessed in this study.
Microsurgical anatomy of safe entry zones to the brainstem
Authors: Cavalcanti Daniel D. , Preul Mark C. , Kalani M. Yashar S. , Spetzler Robert F. 
Published: October 2015

OBJECT
The aim of this study was to enhance the planning and use of microsurgical resection techniques for intrinsic brainstem lesions by better defining anatomical safe entry zones.

METHODS
Five cadaveric heads were dissected using 10 surgical approaches per head. Stepwise dissections focused on the actual areas of brainstem surface that were exposed through each approach and an analysis of the structures found, as well as which safe entry zones were accessible via each of the 10 surgical windows.

RESULTS
Thirteen safe entry zones have been reported and validated for approaching lesions in the brainstem, including the anterior mesencephalic zone, lateral mesencephalic sulcus, intercollicular region, peritrigeminal zone, supratrigeminal zone, lateral pontine zone, supracollicularzone, infracollicularzone, median sulcus of the fourth ventricle, anterolateral and posterior median sulci of the medulla, olivary zone, and lateral medullary zone. A discussion of the approaches, anatomy, and limitations of these entry zones is included.

CONCLUSIONS
A detailed understanding of the anatomy, area of exposure, and safe entry zones for each major approach allows for improved surgical planning and dissemination of the techniques required to successfully resect intrinsic brainstem lesions.
The nondecussating pathway of the dentatorubrothalamic tract in humans: human connectome-based tractographic study and microdissection validation
Authors: Meola Antonio , Comert Ayhan , Yeh Fang-Cheng , Sivakanthan Sananthan , Fernandez-Miranda Juan C. 
Published: October 2015

OBJECT
The dentatorubrothalamic tract (DRTT) is the major efferent cerebellar pathway arising from the dentate nucleus (DN) and decussating to the contralateral red nucleus (RN) and thalamus. Surprisingly, hemispheric cerebellar output influences bilateral limb movements. In animals, uncrossed projections from the DN to the ipsilateral RN and thalamus may explain this phenomenon. The aim of this study was to clarify the anatomy of the dentatorubrothalamic connections in humans.

METHODS
The authors applied advanced deterministic fiber tractography to a template of 488 subjects from the Human Connectome Project (Q1–Q3 release, WU-Minn HCP consortium) and validated the results with microsurgical dissection of cadaveric brains prepared according to Klingler’s method.

RESULTS
The authors identified the “classic” decussating DRTT and a corresponding nondecussating path (the nondecussating DRTT, nd-DRTT). Within each of these 2 tracts some fibers stop at the level of the RN, forming the dentatorubro tract and the nondecussating dentatorubro tract. The left nd-DRTT encompasses 21.7% of the tracts and 24.9% of the volume of the left superior cerebellar peduncle, and the right nd-DRTT encompasses 20.2% of the tracts and 28.4% of the volume of the right superior cerebellar peduncle.

CONCLUSIONS
The connections of the DN with the RN and thalamus are bilateral, not ipsilateral only. This affords a potential anatomical substrate for bilateral limb motor effects originating in a single cerebellar hemisphere under physiological conditions, and for bilateral limb motor impairment in hemispheric cerebellar lesions such as ischemic stroke and hemorrhage, and after resection of hemispheric tumors and arteriovenous malformations. Furthermore, when a lesion is located on the course of the dentatorubrothalamic system, a careful preoperative tractographic analysis of the relationship of the DRTT, nd-DRTT, and the lesion should be performed in order to tailor the surgical approach properly and spare all bundles.
High energy focused shock wave therapy accelerates bone healing
Authors: Kieves N. R. , MacKay C. S. , Adducci K. , Rao S. , Goh C. , Palmer R. H. , Duerr F. M. 
Published: October 2015

SummaryObjectives: To evaluate the influence of shock wave therapy (SWT) on radiographic evidence of bone healing after tibial plateau leveling osteotomy (TPLO).Methods: Healthy dogs between two to nine years of age that underwent TPLO were randomly assigned to receive either electro- hydraulic SWT (1,000 shocks) or sham treatment (SHAM). Treatment or SHAM was administered to the osteotomy site immediately postoperatively and two weeks postoperatively. Three blinded radiologists evaluated orthogonal radiographs performed eight weeks postoperatively with both a 5-point and a 10-point bone healing scale. Linear regression analysis was used to compare median healing scores between groups.Results: Forty-two dogs (50 stifles) were included in the statistical analysis. No major complications were observed and all osteo -tomies healed uneventfully. The median healing scores were significantly higher at eight weeks postoperatively for the SWT group compared to the SHAM group for the 10-point (p <0.0002) and 5-point scoring systems (p <0.0001).Clinical significance: Shock wave therapy applied immediately and two weeks post -operatively led to more advanced bone healing at the eight week time point in this study population. The results of this study support the use of electro-hydraulic SWT as a means of accelerating acute bone healing of canine osteotomies. Additional studies are needed to evaluate its use for acceleration of bone healing following fracture, or with delayed union.