bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of seasonal variability of sperm donors’ semen parameters
Authors: Korneyev Igor A. , Zasseev Ruslan D. , Pashina Ol'ga B. , Mamedov Ali E. , Dogov Al'bert M. , Krylov Oleg A. 
Published: November 2018

Introduction. The concept of seasonal variability of sperm parameters is controversial. However, it should be considered during medical evaluation and solicitation of sperm donors.
Aim. To evaluate seasonal variability of sperm parameters from anonymous sperm donors in a reproductive medicine center.
Materials and methods. A retrospective study of 1252 semen samples from 39 sperm donors (mean age 27.1 ± 3.9 years) in a reproductive medicine center in Saint Petersburg during the period from October 1, 2015 to October 1, 2017 was performed according to WHO 2010 recommendations. Semen volume, sperm concentration, total sperm number, progressive motility, and number of progressively motile sperm were analyzed.
Results. Individual variability in semen parameters was high. The mean ejaculate volume in the summer months was higher than in the autumn, winter, and spring (t = 3.65, p < 0.001; t = 4.18, p < 0.0001; t = 1.92, p = 0.056 respectively). The lowest volume (2.83 ± 1.32 ml) was registered in January. The mean sperm concentration in summer was lower than in autumn, winter, and spring (t = 3.65, p < 0.001; t = 4.18, p < 0.0001; t = 1.92, p = 0.056 respectively). It was higher in winter than in spring and autumn (t = 2.54, p = 0.012; t = 1.72, p = 0.082 respectively). The highest mean sperm concentration was registered in January and the lowest in July (157.2 ± 46.6 and 131.9 ± 44.0 million sperm per ml, respectively). No significant seasonal differences were found in total sperm number, progressive motility, or number of progressively motile sperm (p > 0.1).
Conclusions. The study suggests there is both individual and seasonal variability in sperm donors’ semen parameters. As several semen samples are needed to rate semen quality, we recommend that semen analysis for a potential sperm donor be performed in the summer months.
Systematic review of integration of neonatal and child health interventions with pediatric HIV interventions
Authors: Smith Brianna L , Sara Zizzo Sara , Amzel Anouk , Wiant Sarah , Pezzulo Molly C. , Konopka Sarah , Golin Rachel , Vrazo Alexandra C. 
Published: November 2018

Background/Objectives: In the last decade, many strategies have called for integration of HIV and child survival platforms to reduce missed opportunities and improve child health outcomes. Countries with generalized HIV epidemics have been encouraged to optimize each clinical encounter to bend the HIV epidemic curve. This systematic review looks at integrated child health services and summarizes evidence on their health outcomes, service uptake, acceptability, and identified enablers and barriers.
Methods: Databases were systematically searched for peer-reviewed studies. Interventions of interest were HIV services integrated with: neonatal/child services for children <5 years, hospital care of children <5 years, immunizations, and nutrition services. Outcomes of interest were: health outcomes of children <5 years, integrated services uptake, acceptability, and enablers and barriers. PROSPERO ID CRD42017082444.
Results: Twenty-eight articles were reviewed: 25 (89%) evaluated the integration of HIV services into child health platforms, while three articles (11%) investigated the integration of child health services into HIV platforms. Studies measured health outcomes of children (n=9); service uptake (n=18); acceptability of integrated services (n=8), and enablers and barriers to service integration (n=14). Service integration had positive effects on child health outcomes, HIV testing, and postnatal service uptake. Integrated services were generally acceptable, although confidentiality and stigma were concerns
Conclusion and Global Health Implications: Each clinical “touch point” with infants and children is an opportunity to provide comprehensive health services. In the current era of flat funding levels, integration of HIV and child health services is an effective, acceptable way to achieve positive child health outcomes.
Key words: Africa, HIV, PITC • Child health services • PMTCT, neonatal health • Literature review • Immunization program
Copyright © 2018 Smith et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
First Deployment of a Novel Advanced Tracers System for Improved Waterflood Recovery Optimization
Authors: Ow Hooisweng , Chang Sehoon , Thomas Gawain , Shi Rena , Wang Wei , Chen Hsieh , Poitzsch Martin E. , Abdel-Fattah Amr 
Published: November 2018

Abstract
We are developing an integrated, real-time system for deploying Advanced Tracers cost-effectively in a ubiquitous and potentially long-term way. This campaign is for the sake of increasing the oil recovery factor in large waterflooded reservoirs through improved optimization of the water injection for oil production. This paper explains key features of this novel system and reports main results from the ongoing field test of our second-generation tracer material and detection methodology.
Existing inter-well tracers require elaborate laboratory processing for analysis and are not compatible with ubiquitous or real-time deployment. Additionally, conventional tracer material and service costs are not economically viable for widespread and long-term deployment; also, available material barcodes compatible with carbonate reservoirs may be inadequate to monitor dozens of wells simultaneously. Our system addresses all of these inadequacies using novel materials and detection methods, with detailed modeling studies providing strong justification of the financial benefit of this tracer deployment through quantification of increased oil recovery from waterflooded reservoirs.
Key elements of this new inter-well Advanced Tracers system include: An optically-detectable tracer material that can in principle be detected in real-time or near real-time at low limits of detection (LODs), even in the presence of background oil in producing water by means of an intrinsic oil background-subtraction method. The material also has high mobility in high-salinity carbonate reservoirs.A rich palette of tracer barcodes (potentially 50 - 100 or more) to enable simultaneous injection and sampling in dozens of nearby wells.Modeling feasibility studies, performed on an ensemble of different reservoir geometries and with sensitivity analyses, showing that including routine inter-well tracer data along with injection and production rates improves the history match quality and therefore, the optimization of the water injection and oil extraction rates so as to achieve a few percent increase in net present values (NPV).
Recent field tests of the detectability and discrimination of injected prototype tracer materials will be described.
This work adapts novel technology development at the state of the art of modern nanotechnology and bioanalysis to the long-term reservoir stewardship objectives. The integrated, real-time tracer-detection system promises financial benefits through increased NPV and/or ultimate recovery factor via better optimization of water injection.
Assisted Design of Polymer-Gel Floods in Naturally Fractured Reservoirs Using Neuro-Simulation Based Models
Authors: Alghazal Mohammed , Ertekin Turgay 
Published: November 2018

Abstract
Polymer gel treatments have been widely used by the industry to improve sweep conformance and enhance recovery from highly fractured reservoirs. The success of these treatments depends on several factors that include various reservoir properties and gel design parameters. This paper presents a pragmatic approach to optimize the design of polymer gel treatments to improve oil recovery in naturally fractured reservoirs using neuro-simulation based models.
A full spectrum of fractured reservoir properties and polymer gel treatment design parameters was used to generate base simulation models. Production rate, oil recovery and water cut trends were used as key performance indicators to monitor sweep conformance and evaluate polymer gel design effectiveness. These simulation models were used to construct, train and validate the neural network. The network topology was effectively designed to achieve a good match with the reservoir simulation models.
A given set of reservoir properties including porosity, permeability, net pay thickness, water saturation, polymer gel concentration and injection rate can be optimized using the neural-based model to acquire the desired production rate. Furthermore, results show that the injection rate and cross-linking agent concentration are the most sensitive parameters affecting the production performance. The neural model can be used as an effective screening tool for selecting and designing polymer gel projects as it covers a wide range of field parameters.
This work capitalizes on the ability of artificial expert systems in generating tractable, robust and computationally efficient solutions for complex reservoir models. In particular, this paper presents proxy models that are uniquely developed for the first time to optimize oil recovery in naturally fractured reservoirs using polymer gel conformance treatments.
Unlocking the Potential of Unconventional Oil and Gas Resources in Kuwait
Authors: Husain R. , Al-Wadi M. , Al-Ali S. , Al-Abdullah M. , Al-Fadhli H. 
Published: November 2018

Abstract
To keep pace with increasing importance of unconventional hydrocarbons and consequent changes in the global energy landscape, the State of Kuwait has embarked on a strategic plan of evaluating and developing these resources. Synergistic interpretation of exploration datasets has brought out the exploration potential of the resources. These resources are prolific and occur at multiple stratigraphic levels in diverse settings in carbonate reservoirs.
Two types of unconventional resources, self-sourced hydrocarbons (shale hydrocarbons) and tight hydrocarbons, have been identified and evaluated with workflows specific to each type. The Cretaceous Makhul and the Jurassic Najmah formations have emerged as important self-sourced hydrocarbon reservoirs. The play existence is demonstrated by the presence of free hydrocarbons contents, substantial thickness, overpressures and positive production tests in both plays. The Makhul play is characterized by total organic carbon (TOC) content between 4 - 7% and lies in the middle to late maturity oil window. It is over-pressured and has thickness in the range of 70 - 300 ft. The Najmah play is characterized by TOC content between 9 - 14% and is in the late maturity oil-condensate window. The play is systematically over-pressured, with pressure reaching the natural fracturing conditions. The Najmah play has shale gas and shale oil resource potential, while the Makhul play has potential for shale oil resource. The other speculative shale gas play is Qusaiba Shale which has not been drilled so far in Kuwait. Fractured carbonate units in the Cretaceous Upper Minagish and Upper Makhul; the Jurassic Hith, Najmah, Upper Sargelu and Marrat; and the Triassic Lower Jilh and Lower Khuff constitute the tight reservoir resources. These reservoirs are characterized by porosity typically less than 5% and permeability mostly less than 0.1 millidarcy (mD). These reservoirs are productive in structurally deformed areas where natural open fractures are well developed and critically stressed.
Resource specific and technology intensive multi-disciplinary workflows from play assessment to commercial production are crucial for effective leverage of the unconventional resources.
Enhanced Assessment of Stress Dependent Permeability of Sandstone Rock
Authors: Hamid Osman , Osman Haytham , Alamer Sarah 
Published: November 2018

Abstract
Permeability is one of the most important parameters in formation evaluation, reservoir characterization, and hydrocarbon production. There are many methods in the industry to model in-situ permeability relationship, but it is also critical to know that permeability decreases with the increase of effective stress as has been reported i.e. permeability is sensitive to changes in stress and pore pressure. In this study, a relationship between permeability and effective stress is developed for Sandstone reservoirs using 4Dmodel with a two-way coupling between Geomechanics and fluid-flow.
A relationship between in-situ horizontal stress and permeability has been investigated in several reservoirs around the globe. This paper addresses fundamental controls on stress dependent permeability, as identified through modeling and observations. The model developed provides a description of effective stress and explains the dynamic impact of geomechanical stresses on key production parameters in an effective way. This procedure will lead to a more robust simulation model and history match for the life of the reservoir.
Conventional measurement (porosity, permeably, and grain density) has been observed in sandstone formation, while acoustic slowness is obtained by wireline and/or LWD measurement to create empirical correlations between permeability, porosity, velocity and effective stress. These correlations show a good agreement with available geomechanical data that commonly used in the industry for sandstone Formation. A workflow for modelling is developed to improve formation evaluation and assessment of stress-dependent permeability. The model can help in predicting sweet spot and enhance the long-term productivity
Hole Cleaning Study in Mud Cap Drilling Operation Under Loss and Influx Situation Coincident with Borehole Enlargement
Authors: Naganawa Shigemi , Ishikawa Masaki 
Published: November 2018

Abstract
Mud cap drilling technology would often be an effective solution in drilling through total loss zones otherwise not drillable using conventional methods, even when a formation fluid influx is encountered during operation. In addition to this hazardous situation, however, coincidentally occurred borehole enlargement due to formation instability may cause complex well control issues as well as severe hole cleaning troubles such as pack-off or pipe sticking which sometimes result in an unintended sidetracking.
The previously developed cuttings transport numerical simulator using a one-dimensional transient two-layer model was modified to enable to reproduce lost circulation situations. The simulator predicts transient behaviors of cuttings transport including the amount of cuttings accumulation and annular pressure. In the simulator, a supposed certain loss rate of drilling fluid can be set at a certain depth of loss zone and the rate of cuttings injected with drilling fluid into the loss zone is set according to the loss rate. The extended model can also deal with borehole enlargement with variable wellbore geometries and subsequent cuttings generation from the enlarged hole area due to formation breakout.
Simulation studies on cuttings transport or hole cleaning in occurrence of partial and total loss of circulation and borehole enlargement due to shale instability were conducted, and feasibility of mud cap drilling operation under total loss situation coincident with borehole enlargement was examined. By use of modified cuttings transport simulator, transient behaviors of cuttings accumulation and equivalent circulating density (ECD) during drilling extended-reach wells in occurrence of lost circulation and borehole enlargement were successfully simulated. From the simulation results, the mechanism and the degree of cuttings accumulation under these severe situations were well demonstrated.
Casing Drilling Resulted in Slimmer Hole Design and Significant Cost Savings in the WON Field in Egypt
Authors: Shahin Mohamed , Mohamed Islam , Sofos Panos 
Published: November 2018

Abstract
Drilling through the highly unstable clastic deposits formation has been the major concern in the West of Nile field well planning in Qarun Petroleum Company. The West of Nile wells’ geological column consists of the Clastic Deposits and Abu Roash formations to TD, the Clastic Deposits formation extends from surface to 4600 ft., the upper part consists of unconsolidated sandstones and the lower part mainly consists of siltstone with stringers of shale. Drilling the intermediate Clastic Deposits section has always been challenging and expensive due to its severe wellbore instability. Specially formulated water-based drilling fluid (WBM) was used to stabilize the section, several wiper trips and continuous reaming have been done to ensure a stable borehole before running casing, this was always accompanied with the risk of getting pipe stuck and/or inability to run casing to bottom. Extra and Large-diameter casing strings have been run to split the clastics section which resulted in additional cost and time. The new approach of Drilling with Casing has turned the problematic clastic deposits formation to trouble-free drilling with less and shorter casing strings, it eliminated the Non-Productive Time (NPT) associated with wellbore instability problems and most importantly impacted in changing the well design and enabled to drill slimmer holes. As a result, the overall well cost was reduced by 37% and the economics and field development plan of the WON drilling campaign have changed. In this paper, we discuss the challenges faced by conventional drilling and planning and execution of the Drilling with Casing (DwC) technique that managed to mitigate the wellbore instability issues. We here focus more on well design changes towards slimmer hole after implementing DwC technology.
Polymer Flooding: Surface Facility Design for Mitigating Induced Vibrations and On-field Performance Validation
Authors: Jain Shagun , Vasavada Kavya 
Published: November 2018

Abstract
This paper is in continuation to SPE-187306- MS "Enhanced Oil Recovery - Polymer Flooding: Surface Transfer Facility Design, Graphical Approach for Hydraulics and Tackle Induced Vibrations," with core focus on induced vibrations in surface facilities and corresponding mitigating steps.
Cairn Oil & Gas, vertical of Vedanta Limited, has implemented one of the largest Enhanced Oil Recovery Process (Polymer flood) for its Mangala field (in Rajasthan block). The current facility set up follows centralized polymer handling facility concept. This concept was found to be the most economic and it ensured an optimal utilization of the existing water flood network. Large volume of polymer injection requirement for Mangala polymer project drove the requirement of higher concentrated mother solution to reduce the Central Polymer Facility (CPF) plant size. The CPF is among one of the largest centralized polymer solution preparation facilities in the world, producing 80,000 barrels of polymer mother solution at 15,000 ppm concentration.
The concentrated polymer solution (mother solution) is transferred from the CPF to the various existing well-pads (15 nos.) via a pipeline distribution. The mother solution transfer pipeline network is of over 15 km. Once at the well pads the concentrated polymer solution (mother solution) is diluted with the injection water at a specific dilution ratio. The diluted solution is then injected into the individual wells through the existing injection water lines after boosting the pressure.
However, post Mangala EOR commissioning some piping system failures have been experienced in polymer solution facility. These failures are largely attributed to vibration induced fatigue and arose both, at the suction and discharge lines of the Positive Displacement polymer Injection Pumps. The vibration is attributed mainly to the visco-elastic nature of the polymer fluid.
The paper covers the issue through following steps:
Evaluating the vibration effect on surface facilities and equipment due to polymer fluid rheology Identifying, in detail, the sections of surface facility susceptible to equipment failure and performance loss. Presenting lessons learnt based on field experience Qualifying effective design solutions to address the issues of flow induced vibration Establishing the efficacy of the recommendations through performance evaluation post on-site design modification
A New NMR-Based Height Saturation Model of a Low Permeability Carbonate Reservoir
Authors: Harbi Ahmad Al , Hursan Gabor , Kwak Hyung , Gao Jun 
Published: November 2018

Abstract
Formation evaluation studies suggest that high in the hydrocarbon column, the resistivity logs can precisely quantify fluid saturation due to the large contrast in the resistivities of hydrocarbon-bearing and water-bearing formations. However, in the transition zone where water and oil reside in more or less equal volumes, the determination of hydrocarbon saturation by resistivity value becomes challenging. Some of these intervals exhibit low resistivity pay (LRP) characteristics where resistivity-based log analysis predicts high water saturation, yet they can produce little or no water-cut.
Conventional log-based saturation and rock quality evaluation in a low permeability carbonate reservoir is difficult due to the lack of the input measurement's sensitivity to pore size and the amount of pore-filling fluids. Pore size information provided by Nuclear Magnetic Resonance (NMR) logs from this LRP provides good sensitivity, but it needs to be calibrated for quantitative use. The objective of this study is to determine a height-based NMR Bulk Volume Irreducible (HBVI) cutoff to distinguish and quantify the amounts of reservoir fluids across a wellbore using NMR logs.
The procedure consists of two-part workflow. The first part describes the acquisition of a data base that includes high-quality laboratory NMR and capillary pressure measurements to determine the pore aspect ratio and the effect of temperature on the formation's NMR properties using core samples from the target reservoir. These measurements are then used to underpin the mathematical description of the HBVI cutoff as a function of displacement pressure that is translated to height above the free water level (HAFWL). The second part of the workflow is a well-log processing scheme where the new formula is implemented to calculate a continuous fluid saturation profile across the well using NMR logs.
The laboratory measurements suggest a good agreement between the capillary pressure and NMR T2 measurements. Both data sets indicate a well sorted pore size distribution. The T2 relaxation time increases with temperature, which is then considered in the downhole implementation of the HBVI model. The NMR-based saturation log is consistent with wireline formation testing (WFT) observations and mercury injection capillary pressure (MICP)-based saturation height modeling results in a low resistivity pay reservoir.
The results of this study suggest that the laboratory calibration and NMR log processing workflows described herein provide a viable alternative for the calculation of fluid saturations in complex reservoirs where the conventional log-based saturation evaluation faces uncertainties.
Manage Performance of Suppliers Effectively to Achieve Excellence in Supply Chain
Authors: Kashif Muhammad 
Published: November 2018

Abstract
Supplier Performance Management (SPM) is a process to improve the overall performance of Suppliers, promote better working relationships with Suppliers and remove poor performing suppliers from Pre-qualified Bidders List.
Once SPM is in place Supplier Performance can be tracked, analyzed and shared with confidence. Owner company can clearly identify poor performing Suppliers and work with them to improve their performance.
The steps involved in achieving an effective SPM are Measure Supplier performance, Analyze available data, Communicate/Engage Supplier and work for tangible Improvement.