bluuebunny/crossref_metadata_2025 huggingface dataset:
Big climate data assessment of viticultural conditions for wine quality determination in France
Authors: Tsai Ya-Lun S. , Lin Shih-Yuan
Published: October 2020

Grapevine is one of the economically most important crops especially in Europe. Although its investment value has been widely recognized, the complex interactions between climate and viticulture remain immaturely understood and modeled, which largely limits a reliable investing strategy by using the observed climate conditions to estimate the wine quality. Therefore, with the aim of comprehensively analyzing the climate-viticulture relationship, compared to most previous studies which employed a few climate factors derived from sparsely located meteorological stations, in the present study, we include 22 climate factors, including temperature, water balance, atmosphere, and radiation data provided by a global land assimilation system covering a period of 40 years (1970 to 2010) as well as two large-scale atmospheric teleconnection indices to establish a holistic climate-wine quality model. Moreover, instead of the conventionally used simple regression methods, to deal with the comprehensive but volume climate dataset, we employ the Least Absolute Shrinkage and Selection Operator (LASSO) regression method, which excels in ingesting a massive amount of variables having complex collinearities. In the pre-analysis of correlations between utilized climate factors, it is found that sunlight has the strongest connections with other factors as it correlates with the most number of climate factors. On the contrary, temperature, the conventionally most commonly employed factor, correlates with much fewer factors. Finally, via validation with wine vintage scores derived from two authoritative rating systems, it is ensured that our proposed approach can accurately establish the climate-wine quality models for four well-known wine-growing regions in France, including Alsace, Bordeaux, Burgundy, and Champagne. Due to the more complex climate pattern of Bordeaux compared to other regions, two bank-wise models instead of a bank-merged model is vital for Bordeaux to achieve a similar modeling accuracy. Eventually, a satisfactory vintage deviance explaining accuracy with one standard deviation score residual within ± 6 points can be achieved in all regions. Therefore, based on the established climate-wine quality model together with the observed climate conditions, the wine quality of each region can be reliably predicted, which provides a reliable reference for wine investment.
Sensory characterisation of Bordeaux red wines produced without added sulfites
Authors: Pelonnier-Magimel Edouard , Mangiorou Pinelopi , Philippe Darriet , De Revel Gilles , Jourdes Michael , Marchal Axel , Marchand Stéphanie , Pons Alexandre , Riquier Laurent , Tesseidre Pierre-Louis , Thibon Cécile , Lytra Georgia , Tempère Sophie , BARBE Jean-Christophe
Published: October 2020

Aim: The evolution of consumer expectations has led to the development of new production methods using low inputs. From an oenological point of view, these methods include the production of wines without any SO2 being added throughout the process. These wines are becoming very popular among consumers, but the absence of SO2 during winemaking increases the risk of stability problems. Such wines have been poorly explored in the literature and there is thus a real need for them to be characterised. This study was developed to evaluate whether Bordeaux quality wines produced without added SO2 have their own typicality, and it provides an insight into current wine production.Methods and results: From a batch of fifty-two commercial Bordeaux red wines produced without adding SO2 and twenty red wines made according to the usual winemaking methods, a selection tasting was performed to eliminate wines with at least one defect further to a sensory space evaluation. In a second phase, the Napping test was applied to defect-free wines to evaluate the sensory specificities of wines produced without SO2 addition. The wines without SO2 addition presented a much higher frequency of defects than those with SO2 (70 % vs 15 % respectively). Defects described in wines without added SO2 were: “Oxidation” (47 %), “Volatile phenols” (31 %), “Mousy off-flavor” (10 %), “Reduction” (8 %) and “Vegetable” (4 %). Since the study focused on quality wines with or without SO2 addition, it was difficult for the tasters to discriminate between them according to their overall technical pathway.Conclusion: This approach has revealed that despite the large number of “non-added SO2” wines with defects, upon blind tasting, expert tasters highlighted some “non-added SO2” wines without defects. Nevertheless, at equivalent quality levels within the same geographic region, and in non-targeted sensory tests, wines with and without SO2 addition were considered to be quite similar.Significance of the study: This study was a first sensory step toward the objective characterisation of “non-added SO2” wines, enabling further work to highlight markers of quality in wines without SO2 addition and to develop the production of “non-added SO2” wines without defects. Nevertheless, at this stage, our results show that the absence of sulfites during the whole winemaking process, including bottling, increases the risk of the development of defects.
Facile Synthesis of Solvent Sensitive Fluorinated Graphene Nanoscrolls and Application as a Cathode Material for Lithium Ion Batteries
Authors: Liu Guozhong , Wan Weihong , Cheng Jinsheng , Xu Litianlun , Chen Zhihe , Chen Ali , Zeng Xueqi , Ke Jinying
Published: October 2020

In this work, fluorinated graphene nanoscrolls (FGN) were synthesized via facile chemical methods under simple and mild conditions. Interestingly, the formation of the featured FGN was significantly solvent sensitive. Experimental results indicated that in the presence of aprotic solvent, for example, N,N dimethylformamide (DMF), the reaction system inclined to form the interesting FGN nanostructures. The structure and morphology of the prepared FGN were detailed characterized by atomic force microscopy (AFM), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-ray diffraction (XRD) etc. The obtained FGN was used as a cathode material for primary lithium ion batteries with superior discharge specific capacity (eg. 979.3 mAhg-1), stable discharge platform and high energy density (eg. 2287.9 Wh kg-1), which fosters it a high density, low cost and durable candidate for cathode material for lithium ion batteries..
The Effect of Supervisor Identification on Unethical Pro-Supervisor Behavior: The Moderating Role of Employability Perceptions
Authors: Lee Kangmin
Published: October 2020

Under some employment circumstances, individuals in some organizations are willing to engage in unethical behaviors that benefit one’s own supervisors who have a great power to decide the levels of evaluation and compensation for each individual. In this study two hypotheses were examined. First, based on social identification theory, we hypothesized that individuals’ feeling a sense of oneness with one’s own supervisors promote unethical pro-supervisor behaviors (UPSB). Second, based on a person-situation interactionist model, we hypothesized that this positive relationship is strengthen if the individual perceives lower levels of one’s own employability. Data were collected from 185 individuals of various types of organizations in South Korea. A time-lagged field study supported our hypotheses. In particular, supervisor identification was positively related to UPSB. Further, for individuals with a weaker employability perception, supervisor identification was positively related to UPSB.
Parisian Time of Reflected Brownian Motion With Drift on Rays
Authors: Dassios Angelos , Zhang Junyi
Published: October 2020

In this paper, we study the Parisian time of a reflected Brownian motion with drift on a finite collection of rays. We derive the Laplace transform of the Parisian time using a recursive method, and provide an exact simulation algorithm to sample from the distribution of the Parisian time. The paper is motivated by the settlement delay in the real-time gross settlement (RTGS) system. Both the central bank and the participating banks in the system are concerned about the liquidity risk, and are interested in the first time that the duration of settlement delay exceeds a predefined limit, we reduce this problem to the calculation of the Parisian time. The Parisian time is also crucial in the pricing of Parisian type options; to this end, we will compare our results with the existing literature.
Incorporating Point-of-Care Bacterial Fluorescence into a Wound Clinic Antimicrobial Stewardship Program
Authors: Serena Thomas
Published: October 2020

Background: In 2014 the World Health Organization (WHO) warned of an emerging world-wide crisis of antibiotic resistant microorganisms. In response, government and professional organizations recommended that health care systems adopt antimicrobial stewardship programs (ASPs). In the United States, the Centers for Medicare Services (CMS) mandated antimicrobial stewardship in the hospital inpatient setting. Effective January 1, 2020, the Joint Commission required ambulatory centers that prescribe antibiotics, such as wound centers, to institute an ASP. Chronic wounds often remain open for months, during which time patients may receive multiple courses of antibiotics and numerous antimicrobial topical treatments. The wound clinician plays an integral role in reducing antimicrobial resistance in the outpatient setting: antibiotics prescribed for skin and soft tissue infections are among the most common in an outpatient setting. One of the most challenging aspects of antimicrobial stewardship in treating chronic wounds is the inaccuracy of bacterial and infection diagnosis. Methods: Joint Commission lists five elements of performance (EP): (1) Identifying an antimicrobial stewardship leader, (2) establishing an annual antimicrobial stewardship goal, (3) implementing evidence-based practice guidelines related to the antimicrobial stewardship goal, (4) providing clinical staff with educational resources related to the antimicrobial stewardship goal, and (5) collecting, analyzing, and reporting data related to the antimicrobial stewardship goal. This article focuses on choosing and implementing an evidence-based ASP goal for 2020. Discussion: Clinical trials have demonstrated the ability of fluorescence imaging (MLiX) to detect clinically significant levels of bacteria in chronic wounds. Combined with clinical examination of signs and symptoms of infection, the MLiX procedure improves the clinician’s ability to diagnose infection and can guide antimicrobial use. In order to satisfy the elements of performance, the MLiX procedure was incorporated into the annual ASP goal for several wound care centers. Clinicians were educated on the fluorescence imaging device and guidelines were instituted. Collection of antimicrobial utilization data is underway.
Common Factors in Neurodegeneration: A Meta-Study revealing Shared Patterns on a Multi-Omics Scale
Authors: Ruffini Nicolas , Klingenberg Susanne , Schweiger Susann , Gerber Susanne
Published: October 2020

Neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and Amyotrophic Lateral Sclerosis are heterogeneous, progressive diseases with frequently overlapping symptoms characterized by a loss of neurons. Studies suggested relations between neurodegenerative diseases for many years, e.g., regarding the aggregation of toxic proteins or triggering endogenous cell death pathways. Within this study, publicly available genomic, transcriptomic and proteomic data were gathered from 188 studies and more than one million patients to detect shared genetic patterns between the neurodegenerative diseases and the analyzed omics-layers within conditions. The results show a remarkably high number of shared genes between the transcriptomic and proteomic levels for all diseases while showing a significant relation between genomic and proteomic data only in some cases. A set of 139 genes was found to be differentially expressed in several transcriptomic experiments of all four diseases. These 139 genes showed overrepresented GO-Terms and pathways mainly involved in stress response, cell development, cell adhesion, and the cytoskeleton. Furthermore, the overlap of two and three omics-layers per disease were used to search for overrepresented pathways and GO-Terms. Taken together, we could confirm the existence of many relations between Alzheimer's disease, Parkinson's disease, Huntington's disease, and Amyotrophic Lateral Sclerosis on the transcriptomic and proteomic level by analyzing the pathways and GO-Terms arising in these intersections. The significance of the connection between the transcriptomic and proteomic data for all four analyzed neurodegenerative diseases showed that exploring these omics-layers simultaneously holds new insights that do not emerge from analyzing these omics-layers separately. Our data therefore suggests addressing human patients with neurodegenerative diseases as complex biological systems by integrating multiple underlying data sources.
General Canonical Variational Principle and Noether Theorem, Their New Classical and Quantum Physics, Solution to Crisis Deducing All Physics Laws in Phase Space
Authors: Huang C. , Huang Yong-Chang
Published: October 2020

This paper discovers that current canonical variational principle and canonical Noether theorem of (in)finite freedom systems for different physics systems have neglected doublet extreme value processes of the general extreme value functional that both is derived by variational principle and is necessarily be taken in deriving all ( quantum ) physics laws in phase space, but which have not been done for over one century since Noether's showing her distinguished theorem, which lead to the crisis deriving all (quantum) physics laws (necessary) in phase space. We discover there is the hidden logic cycle that people assume canonical equations, and then they finally deduce canonical equations by the equivalent relation in the whole processes in all current references. We correct the current key mistake concepts that when physics systems take the variational extreme values, the appearing processes of the physics systems are real physics processes, otherwise, are virtual processes in all current references. The real physics should be what after taking the physics systems' variational extreme values, the physics systems' general extremum functional needs to further take the general extremum functional's minimum absolute extremum zero, otherwise, the appearing processes of physics systems still are virtual processes. Conservation current equations and conservation currents, in phase space, of general canonical variational principle and general canonical Noether theorem are, respectively, deduced for the first time. Using the general extremum functionals' doublet extreme value processes, the hidden logic cycle and the crisis in current canonical variational principle and current canonical Noether theorem are solved. Consequently, the new mathematical pictures, classical and quantum new physics in phase space and the new mathematical and physical doublet extremum processes for (in)finite freedom systems are discovered. General canonical variational principle and general canonical Noether theorem naturally are given, which would rewrite all the different sciences in phase space, as key tools of studying and dealing with them.
Sensor for the Characterization of 2D Angular Actuators with Picoradian Resolution and Nanoradian Accuracy on the Microradian Range
Authors: Pisani Marco , Astrua Milena , Thirumalai Srijith
Published: October 2020

High precision angular actuators are used for high demanding applications such as laser steering for photolithography. Piezo technology allows developing actuators with such a high resolution that the characterization of the same is out of the capabilities of commercially available instruments. At INRIM we have designed and built a device to the purpose of characterizing precision 2D angular actuators with a resolution surpassing the best devices on the market. The device is based on a multi reflection scheme that allows multiplying the deflection angle by a factor of 70. The ultimate resolution of the device is 2 prad/√Hz over a measurement range of 36 µrad with a measurement band > 10 kHz. The working principle, the practical realization and the case study on a top-level commercial angular actuator (Nano-MTA2 produced by MadCityLabs) are described.
Hierarchical Coculture of Hepatocyte and Hepatic Non-Parenchymal Cells for Liver Fibrosis Studies in vitro
Authors: Lau Qiao You , Torizal Fuad Gandhi , Shinohara Marie , Sakai Yasuyuki
Published: October 2020

During chronic liver injury, inflammation leads to the development of liver fibrosis— particularly due to the activation of hepatic stellate cells (HSCs). However, the involvement of inflammatory cytokines in HSC activation is unclear. Many existing in vitro liver models do not include these non-parenchymal cells (NPCs), and hence, do not represent the physiological relevance found in vivo. Herein, we demonstrated the hierarchical coculture of primary rat hepatocytes with NPCs such as the human-derived HSC line (LX-2) and the human-derived liver sinusoidal endothelial cell line (TMNK-1). The coculture tissue had higher albumin production and hepatic cytochrome P450 3A4 activity compared to the monoculture. We then further studied the effects of stimulation by both oxygen tension and key pro-fibrogenic cytokines, such as the transforming growth factor beta (TGF-β), on HSC activation. Gene expression analysis revealed that lower oxygen tension and TGF-β1 stimulation enhanced collagen type I, III, and IV, alpha-smooth muscle actin, platelet-derived growth factor, and matrix metallopeptidase expression from LX-2 cells in the hierarchical coculture after fibrogenesis induction. This hierarchical in vitro cocultured liver tissue could, therefore, provide an improved platform as a disease model for elucidating the interactions of various liver cell types and biochemical signals in liver fibrosis studies.
Noninvasive Infrared Analyses for Brain-to-breast Desease by Monitoring Angle-coherent Spectra from Photonic Quantum Ring Laser of Whispering Gallery Modes
Authors: Kwon O'Dae , Yoon Gil Sang , Lee Jeong-Soo , Chung Yoonyoung
Published: October 2020

Noninvasive and portable diagnoses via angle-resolved coherent spectral data are presented. ACTIRS (Angle- resolved coherent tomographic IR spectroscopy) through angle-coherent return spectra from photonic quantum ring laser of whispering gallery modes, which is not photocurrent-converted after the cortical, vascular or muscular diffuse paths, can be a new method for brain/heart studies. Also it will be eligible for frequent do-it-yourself diagnoses of breast cancer before hospital visits. The unique angle-coherent multi-spectra will eventually lead to study ionic or protein contents of cranial, arterial or lactiferous ducts that have been obtained only from uncomfortable biopsy, NMR, CT or mammography. The spectral data can be spatially or temporally improved and correlated for extracting more meaningful diagnostic conclusions
Shape and Spacing Effects on Curvy Twin Sail for Autonomous Sailing Drone
Authors: Pham Minh Ngoc , Ryu Inho , Kim Bugi , Yang Changjo
Published: October 2020

There is an accelerating requirement for ocean sensing where autonomous vehicles can play an essential role in assisting engineers, researchers, and scientists with environmental monitoring and collecting oceanographic data. This paper is performed to develop a rigid sail for the autonomous sailing drone. Our study aims to numerically analyze the aerodynamic characteristics of curvy twin sail and compare it with wing sail. Because racing regulations limit the sail shape, only the two-dimensional geometry was open for an optimization. Therefore, this study’s first objective was to identify the aerodynamic performance of such curvy twin sails. Simultaneously, a secondary objective was to estimate the effect of the sail’s spacing and shapes. A viscous Navier-Stokes flow solver is used for the numerical aerodynamic analysis. The 2D aerodynamic investigation is a preliminary evaluation. The results have shown that the curvy twin sail designs have improved lift, drag, and driving force coefficient compared to the wing sails. The spacing between the port and starboard sails of curvy twin sail is an important parameter. The spacing is 0.035L, 0.07L, and 0.14L shows the lift coefficient reduction because of dramatically stall effect, while flow separation is improved with spacing is 0.21L, 0.28L, and 0.35L. Significantly, the spacing 0.28L shows the maximum high pressure at the lower area and the small low pressure area at leading edges, so the highest lift is generated.
Investigation of Accumulator Parameters for a Novel Hybrid Architecture
Authors: Hijikata Seiji , Ito Kazuhisa , Murrenhoff Hubertus ,   Institute for Fluid Power Drives and Systems (ifas), RWTH Aachen University Campus-Boulevard 30, Aachen 52074, Germany,   Department of Machinery and Control Systems, College of Systems Engineering and Science, Shibaura Institute of Technology 307 Fukasaku, Minuma-ku, Saitama 337-8570, Japan
Published: October 2020

An open center system (OC-System), which is one of the major hydraulic architectures for excavators, has been improved in the world to reduce fuel consumption for global environment conservation and lower operating costs. However, the total system efficiency, including the internal combustion engine (ICE), has not been thoroughly considered. In contrast, a constant pressure system (CP-System) enabling the engine to be driven optimally is developed, but is not accepted in the industry owing to the complexity of the required components. Thus, in this research, a hybrid system combining an OC-System with a CP-System is proposed to improve the total system efficiency. An accumulator, which is used to provide flow rate to actuators, is essential for the new hybrid system, and it is vital to consider the nominal gas volume and pressure level for the accumulator in terms of energy savings and initial cost. Therefore, the influences of accumulator volume and pressure level are discussed in this paper.
Concept and Prototype of Soft Actuator for Liquid Nitrogen Temperature Environments
Authors: Yamaguchi Daisuke , Hanaki Tatsuya , Ishino Yuji , Hara Masayuki , Takasaki Masaya , Mizuno Takeshi ,   Okayama University 1-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan,   Saitama University 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570, Japan
Published: October 2020

A prototype of a soft actuator for extreme environments was fabricated, and driven in a cryogenic temperature environment. Previous soft actuators cannot be used for robots in extreme environments because resin, the main fabrication material, exhibits weak environmental characteristics. Therefore, this study proposes the application of polyimide (PI) films to soft actuators. PI is characterized by excellent environmental resistance. However, the welding of PI is difficult because of its high resistance. In this study, a welding method was developed for PI films. This method does not require pretreatment, or the use of adhesives or additives to reduce resistance. Hence, an actuator that utilizes all the characteristics of PI was realized. The actuator was characterized in a cryogenic environment, which is one of the extreme environments, and was successfully driven at a liquid nitrogen temperature of 78 K. This proposed technology is not limited to cryogenic environments and is expected to provide extreme environmental resistance to existing soft robots.
Clad rolled reinforcing bars
Authors: Ovchinnikov E. S. , Ovchinnikova I. A.
Published: October 2020

Premature destruction of reinforced concrete structures exposed to aggressive environmental influences is a serious problem, both from a technical and economic point of view. Carbon steel reinforcing bar embedded in concrete is usually not subject to corrosion due to the formation of a protective ion-oxide film that passivates the steel under conditions of strong alkalis in the concrete pores. However, this passivity can be disrupted by chlorides penetrating the concrete, or by carbonation reaching the surface of the reinforcing bar. Then the corrosion begins.

An example of a solution to this problem is the replacement of conventional steel reinforcement with clad steel during construction. Through the closely spaced interface of two solid metals, the atoms diffuse with each other at different speeds, at a high temperature, and at a certain pressure. This creates a metallurgical bond between two solid metals, the integrity or «strength» of which depends on the «purity» of the interface between the two metals and on the atoms that make up this «transition zone» or bond.

The article investigates plated rebar, to determine the possibility of production in a mill 320 OJSC «BSW – Management Company of the Holding «BMC». To study the new type of reinforcing bars, special types of research were conducted as determining the chemical composition, microstructure, and mechanical properties. The main advantages of this type of product are defined in the article.
Modernization of the cable car in order to take into account the length of the metal cord at the stage of its final production
Authors: Brezgun S. F. , Negru A. S.
Published: October 2020

To achieve accuracy and stability in measuring the length of the metal cord at the stage of its manufacture, it is necessary to modernize the existing rope-twisting equipment. The upgrade introduced a new algorithm for rope-twisting equipment, changed the length accounting system of the steel cord, used the latest equipment and technology. A contactless electric power transmission system and a wireless data transmission system based on an infrared channel have been introduced.

The use of the latest technologies and our own innovations allowed us to obtain a completely new type of rope-twisting machine that can produce metal cord according to the requirements of the consumer’s specification.
Comparison of Machine Learning Algorithms for the Development of a Forecasting Tool for Cyclic Gas Injection in Hydraulically-Fractured Wells
Authors: Seilkhanov Anuar , Otynshin Daniyar , Novopokrovskiy Georgiy , Artun Emre
Published: October 2020

Single-well cyclic gas injection (cyclic pressure pulsing) is an enhanced oil recovery (EOR) method that includes injecting different types of gases that soaks into formation. In hydraulically-fractured wells, surface area of fracture can help the gas-diffusion process to be more effective. After the injected gas penetrates into the rock matrix, increased pressure and interaction of injected gas with the oil can result in improved production rates. As in all other EOR applications, performance-forecasting is critical to properly design the operational aspects of this application. In situations where a reliable numerical model or reservoir simulator is not accessible, machine learning methods can offer an alternative approach for forecasting the performance in a practical manner. When the dataset used for training is generated from numerical simulation runs, machine learning model serves as a proxy to the reservoir simulator by accurately predicting the performance variables from a set of input parameters. This eliminates the necessity to have access to a reservoir simulator and helps to conduct comprehensive analyses in a timely manner. In this study, various machine learning algorithms were tested to develop predictive models for the cyclic injection process by using a dataset obtained from numerical simulation runs. To design machine learning models, we used the provided database with 5 operational parameters: injection rate, injection time, soaking time, cycle rate, the composition of three injected gases (CO2, N2, CH4) and output as the economic efficiency for each year derived by simulations. Based on the given simulations data, three different machine learning models were constructed: Random Forest, Neural Network, and Multiple Linear Regression. Firstly, data is analyzed by the visualization of input variables and importance identification to observe the correlation between each other and find similar patterns. Secondly, models were created based on input and output variables. Finally, improvement of prediction performance, accuracy optimization, and error computational techniques are applied to each of the three methods using R tool. Among the three algorithms, validation performance of random forests was the best with a coefficient of determination of 0.93.
Integrating Biomarker Analysis with Carbon Stable Isotope Signatures for Genetic Classification and Tracing Possible Migration Pathways of Hydrocarbons of Pre Caspian Basin
Authors: Seitkhaziyev Yessimkhan Sherekhanovich , Uteyev Rakhim Nagangaliyevich , Sarsenbekov Nariman Danebekovich , Tassemenov Yernur Tassemenovich
Published: October 2020

This paper presents the results of gas chromatography-mass spectrometry studies (GCMS-SIM) of 170 oil samples derived from 32 different fields, located in the southern parts of the Pr-Caspian basin for the genetic classification of oils based on their biomarker and aromatic compositions. In addition, 10 representative oil samples from different fields were chosen for carbon isotope analysis of oils, their fractions and individual n-alkanes. The genetic classification based on biomarker distributions revealed different types of oils, distinguishable mainly by lithology of their source rocks: according to their terpane distributions oil samples from Aktube, Dosmukhambetov, S. Nurzhanov, Karasor, Teren-uzek, Akniyaz, Western Prorva and Kisymbai fields were generated in carbonate source rocks, while samples from the rest fields were derived from shaly source rocks. Oils of Karashiganak and Balgimbayev also have a certain contribution of carbonate OM. The results of PCA cluster analysis based on biomarker distributions indicate the presence of genetically different oils in the studied fields. Also it was attempted to determine the direction of hydrocarbon migration pathways between certain objects and horizons.
A Comprehensive Approach to Solving the Problem of Involving the Development of Hydrocarbon Reserves of the Eastern Ustyurt's Field
Authors: Khodos Olga , Maysyuk Dmitry , Ushakov Igor , Yangaliev Farid , Yakubov Ruslan
Published: October 2020

A comprehensive approach to assessing risks and uncertainties using a 3D geological and hydrodynamic model of the field, as well as mapping the least risky zones in terms of the availability of hydrocarbon reserves, was applied in a field in Eastern Ustyurt. The decision to develop hydrocarbon reserves takes into account geological and technological uncertainties. Selecting intervals with increased permeability based on core data by "typing" the section is proposed. The main parameters affecting the reliability of hydrocarbon reserves were analyzed, and the ranges of their changes were determined. The reliability of the structural frame position was evaluated. Algorithms for automating the process of evaluating the best drilling direction in the presence of technical parameter uncertainties are proposed. This differentiated approach to workover planning takes into account general limitations and technological uncertainties.
Conformance Control Completion Unlocks Production Horizons of Tengiz Field
Authors: Kamispayev Akylbek , Saduakassov Bekzhan , Clarke John , Manakhayev Ruslan , Gazizova Alima
Published: October 2020

The team evaluated multiple options for conformance control, with the primary focus on shutting off water. The team broadened the focus to include gas shut off, as well as implementation in the sour gas injection wells, and the water injection wells. The new completions have become the preferred completion for most of the wells. The conformance control packer assembly is selected based on the openhole caliper logs, pressure measurements, drilling breaks, fluid saturations and the thickness of the reservoir intervals. After the drilling rig runs the completion, the wells are completed with a coiled tubing unit. The coiled tubing tools and procedures have improved since the initial swell packer completions. Many of the new wells use smart coil with embedded fiber optic cable to help ensure a successful completion.

The swell packer completions have been very successful as a whole, but not every swell packer is effective in isolating between layers. The Distributed Temperature Sensing (DTS) has been very useful in identifying both leaking packers, as well as communication between zones from within the reservoir. There are several benefits of using the swell packers for mechanical diversion of stimulation fluids. Without the swell packer completions, the average treated zone was 500m thick. Initially, most conformance control completions consisted of three to four packers. Since then the average number of packers has increased to five to six packers per well. Most stimulation treatments now target an interval of less than 100m. There have been several major rig workovers (MRWO) in the sour gas injection area of the field. Comparisons pre and post MRWO well performance indicate that the swell packer improved the productivity of wells.

This paper shows how the swell packer completions have helped to reduce unwanted fluids and enhanced the oil production capability of the wells. It will describe the selection process for packer placement, and the success rate of these packers. The paper also covers the evolution of the coiled tubing procedures that helped to make the conformance control program a success.
The Novel Approach to Pressure Transient Analysis in Highly Fractured Reservoirs: Case Study from Patardzeuli Field, Georgia
Authors: Ramatullayev Samat , Akbayev Beibit , Tsaplin Dmitri , Urazaliev Jenis , Goloborodko Andrey
Published: October 2020

Fractures are common features of many carbonate reservoirs. Given complex flow network that they create, characterization of dynamic behavior of these reservoirs is often complicated and becomes important, especially, if fractures provide primary pathways of fluid flow. In this paper a novel semi-analytical simulator was used to understand the pressure behavior of naturally fractured reservoir containing a network of discrete and/or connected finite and infinite-conductivity fractures.

In this study an integrated interpretation methodology is applied to analyze well test data acquired in open hole section of exploration well drilled into highly fractured carbonate reservoir of Lower Eocene – Upper Cretaceous sediments on Patardzeuli field of Block XI-B, Republic of Georgia. The main steps consisted of explicitly modeling fractures - both wellbore-intersecting fractures and fractures located away from wellbore - using formation microimager data and calibrating the model to actual well test response using a unique novel mesh-free semi-analytical simulator designed for fractured reservoirs.

Study presents the results of well test of one zone performed in highly fractured carbonate reservoir drilled in Patardzeuli field. The pressure-transient response confirmed the complexity of reservoir and dominant contribution to flow regimes from fractures.

It is shown in this paper that there are many factors that dominate transient behavior of a well intersected by natural fractures, such as fracture conductivity, length, intensity and distribution, as well as whether fractures intersect the wellbore or not. Moreover, it was demonstrated that presence or absence of damage on wellbore-intersecting fractures in vicinity of wellbore will impact the pressure-transient behavior of reservoir and shape overall productivity of the well.

The novelty of the approach is the analysis of the dynamic behavior using a unique semi-analytical pressure transient simulator for fractured reservoirs. The simulator can be used to obtain a response for arbitrarily distributed infinite and/or finite conductivity natural fractures within the reservoir by modeling them explicitly. In this study, it allowed to maximize the value of well tests by assessing the effect of fractures on reservoir dynamic behavior and obtain matrix and fracture parameters where conventional well test interpretation tools would be deemed unviable.
Features of Field Development with Tight Carbonate Reservoirs by Waterflooding
Authors: Mukanov Adil Rashidenovich , Bigeldiyev Asfandiyar , Batu Assem , Kuvanyshev Amir Maratovich
Published: October 2020

The Bulak field is a unique oil field located in the South-Turgai basin. It consists of heterogeneous carbonates. Throughout the field, the reservoirs vary from highly fractured clean limestones with strong aquifer to very tight limy claystone with low amount of bed-bound fractures and no water production. Active infill drilling followed after the exploration stage revealed uncertainties related to the main issues of development, i.e., location of new wells, their trajectory, EOR techniques and most importantly, waterflooding.

A comprehensive study was conducted based on all the petrophysical, seismic, geological, and reservoir engineering data. As a result, 3D geological and dynamic models were built. During the analysis, special focus was on geological structure and petrophysical characteristics as well as pressure transient analysis due to drastic changes in reservoir properties within small distances. In addition, the production history and the main stimulation, and EOR measurements, especially fracturing, acidizing and nitrogen huff ‘n’ puff results, were taken into account. Eventually, the waterflooding was simulated to identify its benefits and possible field application.

Based on comprehensive study, the field is divided into several zones. The main criteria for dividing became a lithology that is represented by weathered crust, pure limestones, shaly limestones, limy claystones, and bioliths. Each part requires a different approach in development. If the north part is highly fractured and consists of limestones, water shut off is required due to active aquifer, middle part pressure support and the south part horizontal drilling or sidetracking with multistage high-tonnage fracturing. As a result, waterflooding was decided to be implemented in the part of the field characterized by ultralow permeability formation. Thus, recently, four producers were converted to water injection along with the fact that the injection is performed using low-salinity water. Surprisingly, injectors' rates are high enough, current voidage replacement ratio is sufficient and the results are unexpected.

The reservoir is very complex where the lithology is drastically distributed within a small area. However, most of the territory is represented by very tight formation. Eventually, after several years of fields operation, many aspects became clear after the research work and development strategy was updated. So, the company is ready to develop such an unconventional reservoir that is one of the few fields in Kazakhstan.
Drilling Problems Forecast System Based on Neural Network
Authors: Borozdin Sergey , Dmitrievsky Anatoly , Eremin Nikolai , Arkhipov Alexey , Sboev Alexander , Chashchina-Semenova Olga , Fitzner Leonid , Safarova Elisaveta
Published: October 2020

Optimization, digitalization and robotization of oil and gas technological processes based on the use of artificial intelligence methods are among the prevailing trends of the 21st century. The drilling industry is a prime example of these phenomena. The vector of oil and gas drilling is shifting towards complex objects. The improvement of well drilling technologies allows drilling in geological conditions where it was previously impossible. The construction of wells leads to disruption of the natural thermodynamic and stress-strain state of rocks. It is necessary to take into account all the processes occurring in the well and the near-wellbore zone during drilling for the timely recognition of the onset of various complications and accidents. The average time to eliminate complications and accidents is 20-25% of the total well construction time. The task of reducing this indicator is highly relevant. To solve this problem, the most modern technologies are involved, including machine learning algorithms. The main difficulties encountered when using these technologies are the requirements for artificial neural networks for the minimum necessary number of complications or their representable set for the correct "training" of these networks. This report describes how this problem was solved using a full-scale drilling simulator. The drilling simulator makes it possible to recreate a digital twin of a real well and simulate an almost unlimited number of complications of various kinds on it. This approach allows you to create a sample of the required size for the most efficient training and testing of neural network algorithms. Three groups of complications (stuck-pipe or sticking, loss circulation, kick or gas-oil-water occurrence) and standard drilling operations were simulated to minimize the number of false alarms. A total of 86 experiments were modeled, which were then processed using neural network algorithms. The study revealed that the model of an artificial neural network for predicting future manifestations of complications in the form of the "kick or gas-oil-water occurrence", due to its complexity, is trained more efficiently when using not only the input values of drilling parameters, but also the output results of some auxiliary machine learning models. The latest models are trained to solve both regression problems of the indicator function with the model setting to track changes in certain parameters, and the problem of identifying abnormal situations during drilling in real time. When this module trains an artificial neural network model to detect a pre-accident situation of "kick or gas-oil-water occurrence", the following results were obtained for accuracy: accuracy – 0.89, weighted average f1-score – 0.86. The developed system informs the driller about a possible complication with high accuracy, which allows him to avoid it or minimize the consequences.
Enabling Drillstem Testing in Ansagan Field in High-Pressure, High H2S Pre Caspian Deep Wells
Authors: Burlibayev Askhat , Baishuakov Murat , Aimagambetov Marat , Kydatov Mikhail , Kaipov Yermek , Kumar Pramod , Akbayev Beibit
Published: October 2020

Pre-salt carbonates in the Pre-Caspian Basin have prolific hydrocarbon-bearing formations onshore and offshore. Recent exploration wells more than 5000 m deep in the region have had limited success, mostly due to challenging conditions for well testing. This paper summarizes key elements of one of the first successful drill stem testing (DST) campaigns in Ansagan Field.

The holistic DST design for Ansagan field addressed perforating methods, brine selection, packer and DST equipments material selection for hostile environment with high-pressure, high-H2S fluids, and corrosive acid to be used for stimulation. The surface equipment design had to reliably control the well, separate fluids, measure flow rates, and dispose hydrocarbons with minimum environmental impact. Surface flow rate measurement combined of a multiphase flowmeter and three-phase separator. Downhole samples were collected with a single-phase reservoir fluid sampler.

Calcium & zinc bromide brine with 1.77-SG density proved effective. The specially modified completion packer design was in the well up to 6 months and was successfully retrieved after the test.

Although perforating in these deep high pressure wells was usually performed on wireline, accurate shock prediction and design adjustments managed the risk for using tubing-conveyed perforating (TCP) to perforate large intervals in underbalance conditions allowing to achieve lower skin, and flow the well immediately.

The DST string enabled performing production logging, downhole fluid sampling, and acid stimulation with coiled tubing. Fluid sampling was performed on wireline to preserve gas condensate components at reservoir conditions. The highly accurate memory gauges, real-time operations, and reservoir engineer's support made it possible to acquire accurate data to characterize the fracture distribution, which is vital information in fractured carbonates.

In summary, three wells have been successfully tested with a total of 16 zones at Ansagan field, achieving all well test objectives.
Field Case: Complex Water Inflow Risk Evaluation by Various Surveillance Methods
Authors: Skopich Anton , Neubauer Edward , Sadyrbakiyev Renat , Xing Lingbo
Published: October 2020

Complex surveillance to assess the water inflow risk of a well with an openhole completion in a fractured carbonate reservoir using temperature and geochemistry.

The production rate on the subject well was constrained to mitigate the risk of water production from a lower interval in the naturally fractured carbonate reservoir. Due to a wellbore restriction a production log could not be run to help diagnose the risk of the water inflow. Temperature from the permanent downhole gauge (PDHG) was used to estimate the inflow interval and geochemistry of production oil was used to evaluate the water inflow risk.

The analysis of temperature from the permanent downhole gauge indicated that production was coming from the shallower water free interval. Geochemistry using HRGC (High Resolution Gas Chromatography) and LTM-GC (Low Thermal Mass Gas Chromatograph) analysis was used to assess if the wellbore was connected to the lower wet interval through the fracture network. If the wellbore was not connected to the fracture network, the production constraint could be removed, and the rate increased by approximately 6000 STBPD. The production rate was increased in stages with periodic oil sampling and HRGC analysis to check for a water washing signature which would indicate inflow from the lower wet interval. The well was successfully ramped-up and is still producing water free.

In the absence of production log (PLT) data and a clear difference in fingerprinting signature between producing Units, Oil Geochemistry was used to differentiate producing intervals due to water wash effect of the produced oil signature.