bluuebunny/crossref_metadata_2025 huggingface dataset:
Statistical Evaluation of the Level of Development of Circular Economy in European Union Member Countries
Authors: Fura Barbara , Stec Małgorzata , Miś Teresa
Published: November 2020

In this paper, we have analysed the level of advancement in circular economy (CE) in the EU-28 countries. Firstly, we used a synthetic measure to examine CE advancement in EU countries in each of the Eurostat CE distinguished areas, i.e. production and consumption, waste management, secondary raw materials, and competitiveness and innovation. For the empirical analysis, we applied 17 Eurostat indicators to the CE areas. To find the synthetic measure in 2010, 2012, 2014, and 2016, we used multidimensional comparative analysis, i.e. a zero unitarisation method. Secondly, based on the synthetic measures of the CE areas, we created a general synthetic measure of the CE advancement of the EU-28 countries as well as the countries’ rankings. Thirdly, we classified the countries into groups according to their level of advancement in CE, i.e. high level, medium-high level, medium-low level, and low level groups. Finally, we applied a similarity measure to evaluate the correlation between obtained rankings in two most extreme moments in the period of analysis (2010, 2016). Our analysis covers all EU member states, as well as "old" and "new" EU countries separately. Our results confirm that highly developed Benelux countries, i.e. Luxembourg, the Netherlands, and Belgium, have the highest CE advancement level. Malta, Cyprus, Estonia, and Greece are the least advanced in CE practice. Apart from that, on average, there is some progress in CE implementation, significant disproportions between the EU countries were observed, especially among the "new" member states.
Tackling COVID-19 Pandemic through Research in Latin America and the Caribbean: A Bibliometric Analysis
Authors: Espinosa Isabel , Cuenca Victor , Eissa-Garcés Ahmed , Sisa Ivan
Published: November 2020

Latin America and the Caribbean (LAC) is one of the worst-hit regions globally by COVID-19 pandemic. Yet, scarce literature exists that examines the research strategy of LAC in facing COVID-19. The present study aims to quantify and assess the production of COVID-19 publications in thirty-two countries in LAC during the first half of 2020. A Scopus/PubMed/LILACS search was performed to retrieve research articles related to COVID-19 published from January 1 to July 31, 2020. Subgroup analysis including only original publications was used to better ascertain the contribution of LAC countries, and standardization measures were applied to comparisons of country-specific contributions. We identified 1291 publications across the region. Overall, most articles in the region were non-original (81.6%), and the most productive countries were Brazil (43.9%), Mexico (9.14%), and Colombia (7.98%). This trend shifted to Chile after the standardization. Among original studies, the most common study design was cross-sectional (25.8%). LAC countries generate articles primarily pertaining to diagnosis and treatment (27.4%). In the subgroup analysis, however, epidemiology and surveillance was the most prevalent research focus (24.1%). LAC countries should perform more research with a higher level of evidence to inform health policy making to ease the burden of COVID-19 in the region.
Intraspecific phenotype variations in olive barb Systomus sarana (Hamilton, 1822) population from different rivers is possibly linked to locomotive adaptations in caudal fin
Authors: Biswal Jyotsnarni , Singh Rajeev K. , Mandal Sangeeta , Chandran Rejani , Singh Achal , Sah Priyanka , Lal Kuldeep K. , Jena J. K. , Mohindra Vindhya
Published: November 2020

Systomus sarana (Hamilton, 1822) [D1] is an economically important food fish species occurring throughout Indian rivers, which also has ornamental value. This study focused on morphological variations in S. sarana from five river basins across India, viz., Godavari, Mahanadi, Krishna, Middle Ganga and Lower Ganga. A truss network was constructed by interconnecting 12 landmarks to generate 65 morphometric variables extracted from digital images of specimens sampled from the study locations. Transformed truss measurements were subjected to Principal component analysis (PCA), Canonical discriminant function analysis (CDFA), Box plot and Thin plate spline (TPS) analyses. PCA identified eight truss variables with significant loadings, while CDFA designated two truss variables with potential for explaining discrimination between populations. Anterior attachment of dorsal membrane from caudal fin was identified to be the most important variable that presented variations across the river basins studied. Discriminant analysis correctly classified 70.5% of the specimens into their original populations. Thin plate spline for morphometric shape variation analysis indicated highest specimen-shape variations (warping) in Mahanadi basin. TPS-principal strain ratio on principal components (PC-1, PC-2) further revealed significant divergence among the populations in five river basins studied. Results of the study revealed variation in stocks of the species, on the basis of shape morphometry. The four significant parameters, differentiating specimens from different basins, were linked to caudal fin origin at dorsal side and the centre and possibly indicate plasticity in response to locomotive adaptations.
Growth performance and competitiveness of finfish and frozen shrimp exports in Sri Lanka
Authors: Bandara Tharindu , Abeywickrama L. M. , Radampola K.
Published: November 2020

Frozen shrimp and finfish are important export products in Sri Lankan economy. Careful evaluation of growth trends and competitiveness of these products is important in further value chain development and sustainable economic profits. The present study examined the growth performance and export competitiveness of frozen shrimp and major finfish exports from Sri Lanka during 2000-2015. Analysis of finfish exports showed that bigeye tuna (Thunnus obesus) and yellowfin tuna (Thunnus albacares) were dominant export products. Compound growth rate analysis (CGR) of frozen shrimp indicated that there was a negative growth rate in terms of both export value (-9.3%) and export quantity (-9.07%) during 2000-2015. Fresh chilled fish, frozen fish and fish fillet and other meat have shown positive growth rates in export value (5.09, 10.24 and 70.10% respectively). However, considerable instability (11.07 and 11.74 in terms of value and quantity) was recorded in fish fillet and other meat. Export competitiveness index (XCl) for fresh/chilled fish, frozen fishand fish fillet showed positive competitiveness (XCl>1) during 2001-2015. Revealed comparative advantage (RCA) for finfish exports have shown strong competitiveness (RCA≥ 4) during 2000-2015. Frozen shrimp exports were weakly competitive (1<RCA≤2) during 2008-2015. Finfish exports have shown significant positive growth (p<0.05) in unit value realisation while frozen shrimp exports have shown non-significant (p>0.05) negative growth in unit value realisation. Expansion of export markets for Sri Lankan seafood products, value addition, compliance with international standards and diversification of shrimp exports are important further steps to sustain the competitive position of Sri Lankan fishery exports.
Forearc Crustal Structure of Ecuador Revealed by Gravity and Aeromagnetic Anomalies and Their Geodynamic Implications
Authors: Aizprua Carlos , Witt C. , Brönner M. , Johansen S. E. , Barba D. , Hernandez M. J.
Published: November 2020

Along the Western Cordillera of Ecuador, fault-bounded ophiolites derived from the Late Cretaceous Caribbean Large Igneous Province (CLIP) have provided key petrotectonic indicators that outline the nature and the mechanism of continental growth in this region. However, most of the forearc basement across Western Ecuador is buried under sediments impairing its crustal structure understanding. Here, we propose a first crustal model throughout the spectral analysis of gravity and aeromagnetic data, constrained by observations made both at the surface and at the subsurface. Three main geophysical domains, within the North Andean Sliver in Western Ecuador, have been defined based on spectral analysis and augmented by 2D forward models. An outer domain, characterized by magnetic anomalies associated with mafic rocks, coincides with evidence of a split intraoceanic arc system. An inner domain is governed by long-wavelength mid to deep crust-sourced gravity and magnetic anomalies possibly evidencing the root of a paleoisland arc and the residuum of a partial melting event with subsequent associated serpentinization, the latest possibly associated with an obduction process during the middle Eocene-Oligocene. In addition, our model supports the presence of a lithospheric vertical tear fault, herein the southern suture domain, inherited from an oblique arc-continent interaction. Our interpretation also brings new insights and constraints on the early geodynamic evolution of the Ecuadorian forearc and provides evidence on the structural style and preservation potential of the forearc basement, most likely the roots of a mature island arc built within an oceanic plateau.
Alternative Chemistries for H2S Scavenging – Total Feedback
Authors: Baraka-Lokmane Salima , Nwankwo Chidiebere , Hitta Jérôme , Atherton Lee
Published: November 2020

Hydrogen sulphide (H2S) is naturally occurring in many oil and gas production streams. H2S scavengers are used as additives to reduce the concentration of H2S gas in order to meet export gas/crude specification or for mechanical integrity requirement. Most Total installations today use conventional chemicals such as monomethyl amine (MMA) and monoethanolamine (MEA) triazines for H2S removal. According to Total affiliates, deposit formations have been observed when triazine based scavengers are used. In this paper alternative chemistries for H2S scavenging are assessed. Six H2S scavengers have been evaluated, these are: Methylene bis-Oxazolidine (MBO), Ehylenedioxy Dimethanol (EDDM), 2-Ethyl Zinc Salt, Glyoxal, Hemiacetal and MEA Triazine. For the evaluation of H2S scavenger's efficiency, an experimental method has been developed.

For the selection of H2S scavengers, the following tests have been carried out: (i) evaluation of H2S scavenger efficiency in the oil and gas phase and (ii) production chemical compatibility test. The three-best performing H2S scavengers have been analysed for (i) the impact of H2S scavenger on foaming; (ii) impact of H2S scavenger on emulsion; (iii) compatibility between H2S scavenger and production water; (iv) effect of H2S on the scale inhibitor efficiency; (v) effect of H2S on the corrosion inhibitor efficiency.

Laboratory tests have shown that the three best H2S scavengers, based on the performance test, are Zinc 2-ethylhexanoate, Methylene bis-Oxazolidine (MBO) and Triazine. Methylene bis-Ozaxolidine tested on North Sea site in the multiphase and gas phase has shown preliminary good results. No impact on emulsion, foaming and corrosion were observed from the three-best H2S scavengers selected. Test performed on site with zinc-based product showed very good performance on H2S removal but impacted produced water quality. The zinc-based product formed deposits when mixed with production water therefore this H2S scavenger should not be used for scavenging H2S in the water phase. Though Triazine and MBO based scavengers increase water pH, potential scaling issues can be mitigated by scale inhibitor, however dithiazine deposits formed with the use of triazine based scavengers limits its use for H2S scavenging in oil gas installations.

An experimental method has been developed for the evaluation of H2S scavengers. Alternative scavenger chemistries have been identified. These chemistries reduce the risk of deposit formation in the H2S removal process during oil and gas production.
An Innovative Digital Solution to Support Pipe Welding Assembly Operations
Authors: Masse Thibault , Gotusso Nicolas , Feroldi Jerôme , Mailfait Thibault
Published: November 2020

An innovative digital solution to transform pipe fit-up operations had been developed. It relies on an algorithm providing a full batch of pipes compatibility analysis, and a smartphone app to be used in full autonomy by welding staff providing live fit-up outcomes. This results in optimized welding assembly operations.

Providing pipe-end dimensional measurement and using pipe-end identification technology, the algorithm provides a deterministic analysis of the data to accurately predict the Hi-Lo resulting from all possible pipe-end combinations and then anticipate operational constraints.

The developed app provides tailored recommendations to mitigate risks associated with Hi-Lo specification compliance (such as grouping, quarantine management or non-compatibilities identification) considering operational constraints such as quarantine capacity, welding line cycle time or even accessibility.

During welding operations, no sequencing is required. By scanning two random pipes intended to be welded together, a smartphone app provides live recommendations on the pipe rotations to respect welding requirements. The solution also includes quarantine management, displaying real-time notifications to reintroduce pipes that have been segregated due to limited compatibility.

This results in secured line pipe assembly workflow, improved weld quality and production time reduction.

Innovation lies into bringing full autonomy: in the field, the solution is a simple mobile app to be used by the existing personnel. No additional workforce on-board is required. Additionally, compared to existing solutions, the developed tool brings a deterministic analysis instead of a probabilistic one, and does not require sequencing - thus removing the need for extensive pipe handling.
The Practical Value of Workplace Diversity and Inclusion in the Oil and Gas Sector
Authors: Hamp Roland , Ryan Deborah , Carreras Patricia E.
Published: November 2020

Organisations have long recognised the potential for diverse teams to improve overall creativity, innovation and productivity, thereby achieving consistently better business outcomes - the so called ‘diversity bonus’. This is particularly true and relevant to the oil and gas industry, which constantly has to manage technical and economic uncertainty, major operating hazards, and continually seek business performance improvement and efficiencies, in order to operate sustainably and meet ever higher stakeholder expectations.

However, developing successful diverse teams presents practical questions and challenges, including what type of diversity will really add value to a task, how will a diverse group of people relate to and support one another, how can major innovation be delivered consistently whilst working within highly structured management systems and standards which aim to achieve a high degree of consistency and minimise failure frequency, and what is the most useful role of the manager/leader for such teams?

This paper describes diversity and inclusion in its broadest sense, and its benefits and challenges within the context of the oil and gas industry, in particular with regard to Petroleum Engineering and subsurface teams. A number of common and practical industry situations are considered, and the merits of further opportunities are discussed. The fundamental actions and behaviours that help oil and gas companies promote and establish more diverse and inclusive teams and cultures, in order to deliver outstanding results, are examined.
Application of Cemented Multi-Entry Ball-Activated Frac Sleeves in Multistage Stimulation: Fracture Modeling and Production Prediction
Authors: Bagci Suat , Stolyarov Sergey , Gomez Ricardo , Yang Junjie , Elliott Christopher
Published: November 2020

Plug and Perf (PnP) completions have been the most widely used multistage hydraulic fracturing methods in unconventional wells. In a PnP completion, isolation between stages is achieved by setting frac plugs inside the horizontal liner. The number of perforation clusters and perforation holes are designed using limited entry perforating techniques.

While PnP is a proven method, there are also some downsides, particularly when considering the inability to pump plugs due to changes in casing integrity and casing deformation occurring in 20-30% of horizontal wells. Casing damage has been increasingly recognized as a challenge to well integrity in active or child wells during multistage hydraulic fracturing. Casing deformation and reduction in casing inside diameter (ID) prevent the use of PnP operations due to frac plugs being unable to pass through deformed casing.

Cemented multi-entry ball-activated fracturing sleeves (ME-BAFS) allow users to imitate the limited entry effect of PnP completions while eliminating the need to deploy large OD frac plugs for each stage. The multiple entry points are activated using various-sized frac balls dropped from the surface as the stimulation treatment is pumped, eliminating the need to rig up and rig down between stages. After fracturing is complete, the frac balls either dissolve or are flowed to surface allowing production to begin immediately eliminating through-tubing intervention. The multi-entry ball-activated fracturing sleeves use graduated balls and ball seats to open as many as five sleeves per stage with a single frac ball for increased efficiency. Number of clusters and entry points are calculated based on limited entry techniques similar to PnP.

Within this study, two limited entry techniques, PnP and multi-entry sleeve systems, are evaluated using commercial fracture modeling software, and well production modeling to compare the steady-state production between PnP and multi-entry ball-activated fracturing sleeves. Hydraulic fracture modeling is also used to evaluate limited entry perforation design, perf erosion, stress shadowing, and fracture propagation.
3D Geomechanical Modeling for an Extra Deep Fractured Carbonate Reservoir, Northwest China
Authors: Chen Xiuping , Li Shuangui , Zhang Jun , Wang Shanshan , Gui Feng , Younessi Ahmadreza
Published: November 2020

The development well drilling for the deep carbonate reservoir in Shunbei field, located in Tarim Baisn in Northwest of China, has been challenging because of the great depth, complex lithology, highly fractured reservoirs and the stress condition of the field. Although vertical wells could mostly be drilled to over 7,000 m deep by continuous reaming, deviated well drilling turned out to be extremely challenging. These wells are associated with frequent hole instability related issues such as stuck pipe and pack off, which results in sidetracks. To help understand the different drilling behaviors in different parts of the Shunbei field, a pilot area was selected to construct a 3D geomechanical model to understand the lateral variations in stress and rock properties by integrating the spatial structural and lithology changes. A 3D geomechanical model is built using the well-based models as foundation and integrating the surface seismic interpreted surfaces, attributes and velocity volumes. Based on detailed well-centric geomechanical modeling, an understanding of the three principal stresses, pore pressure and rock mechanical properties and parameters of the formations was previously developed at the offset wells locations in Shunbei field. Rock mechanical properties, pore pressure and stresses were populated in 3D space using inverted seismic volumes and relationships developed in the well-centric models, honoring the 3D static geological and structural models. 3D geomechanical modeling is an effective method to capture the lateral variations away from the offset wells and helps to diagnose and understand the drilling problem in the complex deep carbonate reservoir.
When can Perforating, Wash and Cement PWC Reduce Abandonment Costs?
Authors: Leeson Thomas , Larsen Arne Gunnar
Published: November 2020

PWC is now a field proven method for restoring cemented isolation in casing annuli and has been successfully applied to casing exit repairs, zonal isolations as well as side-track and permanent abandonments. It is a viable alternative to section milling or cutting and pulling casing, with field history also demonstrating that it offers more reliable results than simple ‘perf and squeeze’. It is now accepted in many regulatory locations and is used by a large number of major operators around the world, but it is important to understand the limits of its application.

This paper focuses on illustrating the application envelope for PWC in well abandonment. It will examine the trade-off of service costs versus saved duration, highlighting where a low rig spread rate may drive a decision towards choosing an alternative conventional approach. Furthermore, the paper features and discusses the well parameters such as casing sizes, hole angle, rig capability and annulus content which are key parameters when designing a PWC operation.

Operators and Service Companies have undertaken a large portfolio of Computational Fluid Dynamic (CFD) modelling of PWC operations and more than 70 operations have been subjected to verification by cement quality logging. The paper considers the options for PWC barrier verification and shares when and how CFD and historical cement quality logs from the track record to date has been used to provide confidence in, and verification of, subsequent operations.
Alternative Abandonment Material: Bismuth
Authors: Fulks Jeff , Carragher Paul
Published: November 2020

Well abandonment has traditionally not been thought of as a crucial part of a well’s life, though it is as much a part of a well’s life cycle as drilling and production. As such, traditional methods of abandoning a well utilizing cement and bridge plugs are still common practice among most operators throughout the world. Recently, however, operators have been challenged to find more cost-effective ways to abandon wells without jeopardizing the sealing integrity and have begun to look for "alternative" abandonment materials. Materials such as resins have been utilized by some as an alternative, but there have not been any major new developments in well abandonment materials for nearly 100 years. Although cement, bridge plugs and resins have their benefits, there are also limitations to their sealing capabilities. Bridge plugs lack a high expansion ratio required in some wells and rely on elastomers to seal, limiting their ability to seal in damaged tubing or open hole environments. Due to the unique properties of bismuth, plugs can be achieved with an expansion ratio of 3:1 and take the shape of the environment they are being set in. Cement is porous and lacks the ability to block gasses from migrating through it while bismuth has no porosity, making it an ideal material for stoping gas migration. Resins must be squeezed into an area and can take days to fully cure before a seal is created as opposed to bismuth which flows in a a well via gravity and solidifies to create a seal in a few hours. This paper will demonstrate a new way to create gas tight seals during well abandonment, overcoming the limitations of traditional methods and reducing the operator’s liability and potential environmental impact after decommissioning has been completed.
Real Time History-Matched Models for Unconventional Well Ensures Reliable Forecasting and Rewarding Optimization
Authors: Vahedi Arman , Muruais Miguel , Hernandez Anthonny , Mills John
Published: November 2020

Formulating a robust and efficient production optimization and forecasting tool for unconventional oil and gas assets is a challenging task. This is mainly due to the high number of wells involved and the limited predictability of detailed individual well performance until there is sufficient production history.

Current methods to optimize and forecast production rely on type curves and surface network models, neither of which account for changes in the wellbore condition. Generally, these activities are conducted separately and are rarely fully integrated.

A solution that can automatically match real-time performance of an unconventional asset well is presented in this paper. The implemented solution replicates performance of unconventional wells using transient models. Input parameters for all models honour a given range of realistic operational conditions and are automatically regressed to match the historical performance. At a specified interval, historical production is updated in the models and regression is performed automatically to keep the multiple models updated.

This solution can address challenges related to historical well allocation given by lack of remote sensing, by coupling the well model to a network model. The use of automated regression tools to identify outliers reduces the requirement for routine engineering review, thus making forecasting for thousands of wells manageable. Having accurate well models coupled with a network model allows automatic allocation matching at separator levels and hence a calibrated network model leading to production optimization and better field management. Consequently, a robust optimization and forecasting tool for unconventional assets is achieved.
Erosion and Sand Detection Testing of a Subsea Multiphase Meter with Integrated Erosion Monitoring System
Authors: Streeton Richard , Sanchis Arnaud , Helgaker Jan Fredrik , Piotrowski Pawel
Published: November 2020

This paper presents results from a flow test performed by TechnipFMC (TFMC) in December 2019 at the DNVGL Materials Laboratory in Oslo. A replica subsea multiphase meter (MPM) that includes a Venturi was used firstly to calibrate an Acoustic Sand Detector (ASD) for the X-mas Tree (XT) specific geometry, and secondly to monitor the impact of sand over the life of a typical high-rate subsea gas well.

The replica subsea MPM body was built to mimic the subsea installation on a 5-inch TFMC Subsea 2.0 XT. Several sensors were then mounted on the test rig – including ASDs and Wall Thickness Monitors (WTM) on the MPM block. Phase 1 testing was conducted over a range of air velocities with various sand particle sizes and with water injection to assess ASD sensitivity. In Phase 2, high air velocity and simultaneously high sand loading were applied to evaluate the response of erosion monitoring sensors and the mechanical robustness of the system.

It was shown that the sensitivity of the ASD mounted on the MPM block was satisfactory and that furthermore, standardized calibration curves can be generated, thereby allowing a more accurate measurement of the sand mass flow rate for the specific XT geometry. The capability of WTMs placed at the meter Venturi to monitor long-term erosion was also demonstrated.

To our knowledge, such a complete flow test with sand has never been performed on a full-scale subsea MPM geometry. The knowledge produced has allowed the verification of the accuracy of CFD erosion models, ASD calibration and the potential for development of an Erosion Monitoring System (EMS) using inputs from a range of sensors integrated into a single ROV-retrievable XT mounted metering system.
Pressure and Rate Transient Analysis via Permanent Downhole Gauges – Application and Challenges at Wheatstone Field
Authors: Xia Zhi , Haynes Andrew , Ong Cheng-Sun
Published: November 2020

The Wheatstone gas field located in the Northern Carnarvon Basin offshore Western Australia achieved first gas in mid-2017. All seven foundation producers are equipped with permanent downhole gauges (PDHGs) for real-time pressure monitoring. Data from these gauges have been instrumental in understanding dynamic reservoir performance and reducing static uncertainties. The scope of this paper specifically covers the use of pressure and rate transient analyses (PTA and RTA) and the insights that have been gained during the first two years of production.

Significant offset distances exist between each PDHG and the reservoir. Corrections were developed to convert the gauge pressure to a reservoir datum, which primarily account for frictional and gas density changes with varying rates and temperatures within the wellbore. Other physical constraints and effects have been found to be more challenging to overcome, limiting the quality and interpretability of the pressure transients, particularly in the middle-time region. These include interference from non-reservoir pressure signals such as liquid fallback during shut-in, extremely low signal-to-noise ratios in the higher quality formations, and proximity to boundaries that render a short infinite-acting radial flow (IARF) period that could be masked by wellbore storage.

Attempts to circumvent these issues have included the use of drawdown transient analysis to complement build-ups. The step-rate test can eliminate liquid fallback entirely, which allows for better resolution of the IARF period. Rapid choke movements were also trialled to boost the reservoir response in some instances. Interpretations using the drawdown data were further verified in one producer through analysis of the buildup data acquired following a routine downhole safety valve closure, which benefitted from the trapping of condensed liquid above the closed valve. This provided the cleanest PTA data seen outside of drill stem testing during field appraisal. While successful in the example presented, no methods have yet been found to reliably increase IARF interpretability in those wells producing from the best quality sands.

Regarding RTA, the authors have found very few documented cases in the literature of applying this technique to conventional gas fields. To field-test its applicability in such an environment, evaluations of drainage volume by producer were performed and found satisfactory when compared with other estimates of gas in-place. It is hoped that a presentation and discussion of this finding will be additive to the reservoir engineering toolkit.
Successful Preservation Methodology on Gas Lift Network Pipeline and Wells in Offshore Field Fields
Authors: M. Al-Dhafeeri Abdullah , M. Al-Enezi Bader , A. Atwa Elessawy , A. Al-Aklabi Sultan , Fouad Abo Zkery Shebl , A. Al Sdeiri Saad
Published: November 2020

Operation philosophy at an offshore field is relying on gas lift wells as an artificial lift. The contribution of gas lift wells is essential to achieve the Maximum Sustainable Capacity (MSC). Gas lift system included high- pressure gas piping network system to supply the required gas volume from onshore gas plant, which connected to offshore gathering facilities to feed oil producer wells. Dry gas source obtained from onshore compression plant through 12" high- pressure gas line with 1,250 psi. The major challenge is to preserve the gas-piping network and gas lift wells at a safe manner and a cost-effective approach. An attempt was made to maintain a minimum pressure at value of 150 psi in order to minimize a risk related to pipeline collapse and to shipment collusion at offshore area. A new approach was utilized to bleed off the high-pressure gas network and casing annulus of gas lift wells from operating value of 1,250 psi to the required pressure value of 150 psi. This approach was managed thorough the gas lift pipeline network as loops in terms of pressure and pipeline connection. Each pipeline loop consists of four inter-connected lines ended by one gas lift well at wellhead jacket. The results showed a successful preservation approach to bleed-off high-pressure gas lift wells with connected pipelines occupied with large volume of dry gas at a cost effective and a safe manner. A self-elevating service vessel was utilized to perform the task with proper procedures and safety measurements. The production casings which were occupied with high volume of dry gas had been successfully bled down at an acceptable pressure to ensure well integrity. The approach covered 20 loops related to offshore gas lift network pipelines at safe and cost effective manner. The new technique added a great value on preservation methodology in term of the released high-pressure gas from gas lift network and producer wells to resolve issues related to air emission and hazard potential through the surface testing equipment with its burner. Challenges, methodology, risk assessment, work schedule, findings and lesson learned will be discussed in this paper.
Revitalising Low Contrast Viscosities Between Oil and Water Reservoir Using Autonomous Inflow Control Device AICD Completion Strategy
Authors: M. Ariffin M. Hafizi , Bakar HAsmizah , Kumar AShok , ABD Rahman Roziman , M. Yusuf M. Nurudin
Published: November 2020

To control and equalize the horizontal well drawdown, Autonomous Inflow Control Device (AICD) are planned to be installed along the homogenous reservoirs in five infill wells at B field, Sarawak offshore (Malaysia). The very low viscosity contrast between oil and water (0.6cp and 0.5cp) with 37API degree at B gives unfavorable mobility ratio and water flows with a higher velocity than the oil. This paper presents the interdisciplinary approach to completion design needs which evaluated the efficiency and performance between conventional completions compared with passive inflow control device (ICD), AICD namely Rate Control Production (RCP) and Fluidic Diode to qualify the representative technologies for use at B fields. The very purpose of this flow control device is the extension of well life due to deferment of water and/or gas production prior to water and/or gas breakthrough occurs. Flow performance tests are used to measure the performance of these various flow control devices at representative downhole conditions. The comparative analysis was primarily based on elapsed time comparisons for water/oil ratio (WOR), gas/oil ratio and water cut and sensitivity to historical drawdown, productivity index and production cumulative performance. To reduce formation damage and screen plugging effect in these horizontal section, appropriate fluid conditioning, fluid displacement, filter cake breaker system and compatibility between screen and the fluid in which the bottom hole assembly (BHA) will be deployed are discussed in this paper. The gas-water-control completion using AICD technology is predicted to provide significant benefit during the field development with incremental oil recovery around 10-40%, allowing well production with low water and gas production.
Identification of drugs targeting multiple viral and human proteins using computational analysis for repurposing against COVID-19
Authors: Kumar Sugandh , Kumari Pratima , Agnihotri Geetanjali , Kumar Preethy V , Singh Bharti , Khan Shaheerah , Beuria Tushar Kant , Syed Gulam Hussain , Dixit Anshuman
Published: November 2020

The SARS-CoV2 is a highly contagious pathogen that causes COVID-19 disease. It has affected millions of people globally with an average lethality of ~3%. Unfortunately, there is no standard cure for the disease, although some drugs are under clinical trial. Thus, there is an urgent need of drugs for the treatment of COVID-19. In the current studies, we have used state of the art bioinformatics techniques to screen the FDA approved drugs against nine SARS-CoV2 proteins to identify drugs for quick repurposing. The strategy was to identify potential drugs that can target multiple viral proteins simultaneously. Additionally, we analyzed if the identified molecules can also affect the human proteins whose expression is differentially modulated during SARS-CoV2 infection. The differentially expressed genes (DEGs) as a result of SARS-CoV2 infection were identified using NCBI-GEO data (GEO-ID: GSE-147507). Targeting such genes may also be a beneficial strategy to curb disease manifestation. We have identified 74 molecules that can bind to various SARS-CoV2 and human host proteins. Their possible use in COVID-19 have also been reviewed in detail. We hope that this study will help development of multipotent drugs, simultaneously targeting the viral and host proteins, for the treatment of COVID-19.
Leakage Calculation Method of Carbon Fiber Brush Seal Based on Porous Medium
Authors: Zhang Yan-Chao , Du Chun-hua , Zhao Rui , Cui Ya-Hui
Published: November 2020

As a kind of flexible high-speed dynamic sealing device, brush seal has a good application prospect in high-speed dynamic sealing parts of major equipment, such as gas path of aircraft engines, rocket motors and gas turbines. However, the theoretical research and practical engineering application of brush seal are limited because there are some problems in the practical application. For example, the tip of bristle burned by friction heat under high speed, increased wear and the difficult calculation of leakage. To this end, the structure of the brush seal use the carbon fiber instead of the high-temperature alloy metal bristle. Then the carbon fiber brush volume equivalent diameter is used to establish the carbon fiber brush resistance calculation model based on the porous medium method, which construct the leakage calculation model of the carbon fiber brush seal. Finally, they are obtained by solution of the model in Fluent software that the leakage flow characteristics of the carbon fiber brush seal at work and the influence of different working conditions and structural parameters on the leakage performance. The results show that the carbon fiber calculation model has better adaptability, and the calculation results also show that the carbon fiber brush seal has a lower leakage than the metal bristle under the same working condition. Moreover, the linear factors affecting the leakage of the carbon fiber brush seal are the height of the back plate and the diameter of the bristle, and the height of the front baffles has little effect, while the nonlinear factors are the thickness of brush and the angle of the bristle arrangement. The study provide an significant reference for high performance design of brush seal and its engineering applications.
Posterior Ligamentous Complex Reconstruction for Cervical Dislocation and Instability in Patients without Vertebral Fracture with Artificial Ligaments: A Technical Note
Authors: Huang Chengyi , Wang Beiyu , Liu Hao , Wu Tingkui , Huang Kangkang , He Junbo , Abudouaini Haimiti , Ding Chen , Chen Hua
Published: November 2020

Introduction: The posterior ligamentous complex (PLC) offers restraints to deformation in a complex and interconnected manner. The stability and range of motion (ROM) of the posterior cervical spine is greatly restricted when the PLC is damaged, even without bone disruptions. We describe a novel surgical technique, its advantages, and the postoperative condition of the first patient to use artificial ligament in a reconstruction surgery of PLC injuries in patients without lower cervical vertebral fracture. This technique aimed to fully retain the mobility of the injured segment based on spinal stability and apply dynamic reconstruction in patients’ treatment.Method: We present a detailed description of the reconstruction surgery with artificial ligaments performed on C4-6 PLC injuries in a 27-year-old male presented with neck pain and restricted movement following a high fall injury accompanied by impaired movement of limbs. Results: Immediately postsurgery, the patient’s neck pain and quadriparesis had been improved. The spinal canal decompression and cervical spine sequence results were satisfactory, the facet joint face was in a good position, and the spinous process spacing returned to normal. After three months of rehabilitation, the patient reported improvement of symptoms and the physical and imaging examination showed a significant improvement in the patient’s condition. The patient’s neck mobility motor function had improved further.Conclusion: The present data demonstrate that the novel technique for reconstruction of PLC injury is feasible and safe. However, familiarity with cervical anatomy and adequate experience in lateral mass screws placement during surgery is crucial for this procedure. Therefore, a highly experienced cervical surgery team is recommended to perform the surgery.
Ethnobotanical study on the medicinal plants in khosh Yeilagh rangeland, Golestan province, Iran
Authors: Kiasi Yasaman , Forouzeh Mohammad Rahim , Mirdeilami Seyede Zohreh , Niknahad-Gharmakher Hamid
Published: November 2020

BackgroundIran is of the species-rich areas in diversity of plants, especially medicinal plants being renowned worldwide as crucial for people’s health. Ethnobotany is the information retrieval science of unwritten experiences and is one of the valuable ways to develop the science of medicinal plants and herbal medicine. Objective : This present study aims to identify medicinal plants used widely by local people in Azad Shahr (Golestan province), collect information about diseases treated by using these plants, and boost indigenous knowledge concerning medicinal plants used by local people.MethodsAn ethnobotanical survey was conducted to document indigenous knowledge on medicinal plants uses among local people in Khosh Yeilagh rangelands within 2 years (2018-2020). The data were collected by using field observation, participatory and semi-structured interviews with 41 people (11 male, 30 female). A snowball sampling technique was used to selecte the interviewees. The collected information were categorized based on local names, parts consumed, medicinal properties, consumption habits, and other uses of wild edible plants, WEPs.ResultEighty-four plant species belonging to 27 families were identified in the study area. Most plant species in the region were respectively Lamiaceae (20 species), Compositae (12 species) and Legominaceae (6 species). The results showed that the most frequent medicinal plants were used for gastrointestinal problems (34%), cough and colds (18%), and respiratory disease (13%).ConclusionThe presence of various species of medicinal plants and vast indigenous knowledge in Khoshyilagh rangelands indicate the richness of this area. Research on these plants can pave the way for discovering new medicine in the field of treatment and for preserving these valuable reserves as well as preventing the disappearance and destruction of herbs.
Pilot Evaluation of an Enzymatic Assay for Rapid Measurement of Antiretroviral Drug Concentrations
Authors: Olanrewaju Ayokunle O. , Sullivan Benjamin P. , Bardon Ashley R. , Lo Tiffany J. , Cressey Tim R. , Posner Jonathan D. , Drain Paul K.
Published: November 2020

Objective: Maintaining adequate drug adherence is crucial to ensure the HIV prevention benefits of pre-exposure prophylaxis (PrEP). We developed an enzymatic assay for rapidly measuring tenofovir-diphosphate (TFV-DP) concentrations – a metabolite that indicates long-term PrEP adherence.Setting: The study was conducted at the Madison HIV Clinic at Harborview Medical Center in Seattle.Methods: We enrolled adults receiving standard oral PrEP, and individuals not receiving any antiretrovirals. We measured TFV-DP concentrations in diluted whole blood using our novel REverSe TRanscrIptase Chain Termination (RESTRICT) assay, based on inhibition of HIV reverse transcriptase (RT) enzyme. Blood samples were diluted in water, DNA templates, nucleotides, RT, and intercalating dye added, and results measured with a fluorescence reader—stronger fluorescence indicated higher RT activity. We compared RESTRICT assay results to TFV-DP concentrations from matched dried blood spot samples measured by liquid chromatography tandem mass spectrometry (LC-MS/MS) using ≥700 fmol/punch TFV-DP as a threshold for adequate adherence (≥4 doses/week).Results: Among 18 adults enrolled, 4 of 7 participants receiving PrEP had TFV-DP levels ≥700 fmol/punch by LC-MS/MS. RESTRICT fluorescence correlated with LC-MS/MS measurements (r=-0.845, p<0.0001). Median fluorescence was 93.3 (95% CI: 90.9 to 114) for samples <700 fmol/punch and 54.4 (95% CI: 38.0 to 72.0) for samples ≥700 fmol/punch. When calibrated to an a priori defined threshold of 82.7, RESTRICT distinguished both groups with 100% sensitivity and 92.9% specificity. Conclusions: This novel enzymatic assay for measuring HIV reverse transcriptase activity may be suitable for distinguishing TFV-DP concentrations in blood that correspond to protective PrEP adherence.
Comparison of Dyad Versus Individual Simulation-Based Training on Stress, Anxiety, Cognitive Load, and Performance: A Randomized Controlled Trial.
Authors: Abbott Eduardo F. , Laack Torrey A. , Licatino Lauren K. , Wood-Wentz Christina M. , Warner Paul A. , Torsher Laurence C. , Newman James S. , Rieck Katie M.
Published: November 2020

Objective: Dyad learning has been shown to be an effective tool for teaching procedural skills, but little is known about how dyad learning may impact the stress, anxiety, and cognitive load that a student experiences when learning in this manner. In this pilot study, we investigate the relationship between dyad training on stress, anxiety, cognitive load, and performance in a simulated bradycardia scenario. Methods: Forty-one fourth-year medical school trainees were randomized as dyads (n=24) or individuals (n=17) for an education session on Day 1. Reassessment occurred on Day 4 and was completed as individuals for all trainees. Primary outcomes were cognitive load (Paas scale), stress (Cognitive Appraisal Ratio), and anxiety levels (abbreviated State-Trait Anxiety Inventory). Secondary outcomes were time-based performance metrics. Results: On Day 1 we observed significant differences for change in anxiety and stress measured before and after the training scenario between groups. Individuals compared to dyads had larger mean increases in anxiety, (19.6 versus 7.6 on 80-point scale, p=0.02) and stress ratio (1.8 versus 0.9, p=0.045). On the Day 4 post-intervention assessment, no significant differences were observed between groups. Secondary outcomes were significant for shorter time to diagnosis of bradycardia (p=0.01) and time to initiation of pacing (p=0.04) in the dyad group on Day 1. On Day 4, only time to recognizing the indication for pacing was significantly shorter for individual training (Hazard ratio [HR] = 2.26, p = 0.02).Conclusions: Dyad training results in lower stress and anxiety levels with similar performance compared to individual training.
Human Cost of Tyranny in Kurdistan Region of Iraq
Authors: Ameen Jamal
Published: November 2020

BackgroundThe 2003 liberation/invasion of Iraq and the resulting casualties from civilians and armed forces attracted researchers publishing in high prestigious journals but little was mentioned about the events that led to the armed intervention. This paper assesses the human cost of successive Iraqi governments’ tyrannical rule in Kurdistan Region of Iraq over three decades.MethodThe two most recent and reliable census datasets of 1947 and 1957 were used to estimate fertility and survival rates by age group under normal circumstances. These were used in the classical Leslie Matrix to predict the 2007 Kurdistan Region of the Iraqi population. Results were contrasted with estimates for the same year that were obtained by the World Food Programme as part of their Food Security Analysis for Iraq to arrive at estimates that would indicate the scale of the loss in human capital from Saddam Hussein’s tyranny. FindingsThe Kurdistan Region has lost around 1,911,479 people of which 1,043,549 were male and 867,930 female of different age groups. These include the direct victims of past genocide actions of successive Iraqi governments as well as those who sought refuge beyond the boundaries of the Kurdistan Region during past decades. InterpretationSaddam Hussein’s actions were directed to all indigenous inhabitants irrespective of gender and age. As such, any possible offspring, had life continued as normal, is counted as human loss. Demographical, socio-political and the environmental impact of Saddam Hussien’s tyrannical rule are worthy of further investigation.