bluuebunny/crossref_metadata_2025_split huggingface dataset:
Actividad fungistática y fungicida de extractos etanólicos de propóleos sobre el crecimiento in vitro de cepas del género Candida
Authors: Joya Milagros , Gil Marielsa , Bastidas-Pacheco Gilberto 
Published: October 2017

Los extractos etanólicos del propóleos poseen actividad antifúngica en diferentes especies de levaduras, propiedad de importancia por ser una opción terapéutica económica y poco toxica respecto a los antimicóticos tradicionales, de particular utilidad sobre especies del complejo Candida albicans, patógeno oportunista. A pesar de que la composición química general del propóleos es similar en las distintas regiones del mundo, su actividad antifúngica no parece serlo. El objetivo fue determinar la actividad fungistática y fungicida de propóleos venezolano y de 3 regiones del mundo. Para ello cepas del Complejo C. albicans, C. guillermondi, C. krusei y C. tropicalis se enfrentaron a distintas concentraciones de extractos etanólicos de propóleos. Los propóleos de mayor actividad biológica fueron los de Alemania e Italia (10,2 mg/mL), seguidos por el de Venezuela (15,6 mg/mL) y España (18,8 mg/mL). La CMI en las especies más sensibles a los propóleos fueron C. krusei y C. guillermondii (8,6 mg/mL como promedio de los 4 propóleos). Los extractos etanólicos de propóleos italiano y alemán son fungicidas en todas las cepas estudiadas en diluciones de 1/32 (concentración final de 3,12 mg/dL). Se concluye que los extractos etanólicos de propóleos tienen efectos fungistáticos y fungicidas sobre las especies del Complejo C. albicans, C. krusei, C. guillermondii y C. tropicalis; que C. tropicalis es la especie más resistente a la acción biológica del propóleos y C. krusei y C. guillermondii las más sensibles; que los propóleos de Alemania e Italia son los más efectivos contra las especies de Candida aisladas de pacientes venezolanas.
Optimizing the Development of Tight Reserves of the V. Vinogradov Field using Multi-Stage Hydraulic Fracturing
Authors: Karpov V. , Parshin N. , Chertenkov M. , Veremko N. , Aleroev A. , Kuchmezov Sh. 
Published: October 2017

Abstract
The work describes the implemented techniques which help optimize reservoir engineering for tight oil deposits with the usage of multi-stage hydraulic fracturing by up-to-date methods of fracturing values’ evaluation. The work also identifies reasons of high water cut of well production after the multi-stage hydraulic fracturing at the V. Vinogradov field. The work also describes principles of preparing and implementing the optimum design of the multi-stage hydraulic fracturing under the conditions of unconstrained growth of the vertical component of the hydraulic fracture without any restraining barriers. After the set of operations, the quality of hydraulic fracture control increased and the well production water cut reduced.
New Approaches in the Development of Carbonate Deposits
Authors: Povzhyk P. P. , Privalov V. V. , Kudryashov A. A. , Serdyukov D. V. , Zhuk I. V. 
Published: October 2017

Abstract
New approaches to the development of reserves accumulated in carbonate reservoirs are based on the classification of deposits by a number of characteristics, the development of approaches and technologies for each class of deposits that will allow to achieve maximum oil production, as well as on demonstration of their feasibility using the hydrodynamic models with account being taken of geological and field data. The idea of this project is to create effective reservoir development technologies based on the synthesis of the latest knowledge in geology, seismic, geological and hydrodynamic simulation, current level of technology and stimulation techniques, field development and oil production experience. This paper offers an algorithm for identification of causes that limit production levels and oil recovery rate (ORR). Based on the identified limiting factors and reservoir class, the most efficient reserve recovery technology is selected and justified. Based on the studies, six groups of deposits were identified and approaches for efficient recovery of reserves were formed. Integrated approaches include traditional and pioneer technologies: sidetracking with fracturing/multistage fracturing; water injection using the MCPS and HPS; transient waterflooding using hydrodynamic and physicochemical advanced recovery methods; dual injection technology; thermal gas treatment technology; desalinization technology (dissolution of catagenetic halite); technology of well operation using the pumping equipment with a packer.
The novelty of the research is that efficient approaches have been developed aimed at increasing the ORR with account being taken of the geology of carbonate reservoir rocks. The deposits classification makes it possible to accurately determine the approaches to the development of oil fields, which in its turn will increase the recovery rates and oil production. This approach has allowed to stabilize oil production in the Republic of Belarus (BLR) over the last 5 years, despite the deteriorating structure of total recoverable reserves.
Optimum Practices to Mitigate Gas Migration Problems in Deep Gas Wells
Authors: Al-Yami Abdullah , Mukherjee Tushar S. , Riskiawan Arris , Wagle Vikrant 
Published: October 2017

Abstract
Gas Migration through cement columns has been an industry problem for many years. The most problematic areas for gas migrations occur in deep gas wells. To control gas migration, cementing practices should be optimized. The cementing practices include cement composition, drilling fluids composition, spacer composition and operations such as pumping procedure and pressure testing.
Gas migration can occur due to settling in high-density cement slurries. Cement densities required to successfully cement the zone could be as high as 170 pcf (Pounds per Cubic Foot). As cement slurry sets, hydrostatic pressure is reduced on the formation. During this transition, gases can travel up through the cement column resulting in gas being present at the surface.
Gas migration problems can also occur due to poor displacement. Spacers, cements and drilling fluids should be designed and tested for compatibility for good displacements and bonding. Different types of spacer is required for each type of drilling fluid such as salted drilling fluid or oil based fluids. Testing should include running rheology tests, thickening time tests and compressive strength development tests.
Cement shrinkage is another factor that can cause gas migration problems. Expansion additives are usually added to overcome this problem. However, attention should be made to optimize the concentration and type used to avoid over expansion behavior that can cause micro cracks in the cement matrix. Different cycling effect in temperature and pressure can cause gas migration channels due to creation of micro cracks.
This paper highlights some of the effort to prevent casing/casing pressure leaks from deep gas wells.
Automatic System of Drilling Parameters Field Data Analysis
Authors: Galeev S. R. , Lind Yu. B. , Gabbasov B. M. , Sharipov T. R. , Shlychkov K. E. , Khashper B. L. 
Published: October 2017

Abstract
The purpose of the work is development of automatic system of field data analysis which allows making recommendations on selection of optimal drilling parameters (kind and parameters of drilling fluid, type and characteristics of bits and motors) on the base of field data on drilled wells of an oilfield for effective drilling meterage of wellbore and prevention of troubles in drilling new wells.
The authors have developed automatic system containing database, web-interface and data analysis modules. Modules for statistical analysis of field data on drilling parameters implement nonparametric regression methods for making recommendations on trouble prevention and elimination actions and statistical methods of optimal drilling modes selection.
Retrospective analysis of developed system revealed good agreement between the predicted values of losses intensity and the actual data (results are the same in 88% of cases). So application of developed automatic system for drilling designing allows increasing quality of decision making, reducing probability of abnormal situations emergence and well construction costs.
Experience in Stimulating Multilateral Horizontal Wells using a Multilateral Reentry System and a Dispersion of Acid and Solvent and a Viscoelastic Diverting Acid
Authors: Galiev T. , Zelentsov A. , Golitsina E. , Khabibullin R. , Nifontov N. , Nurullin A. M. , Gaynetdinov R. F. , Burdin K. , Starodubtseva K. , Gromovenko A. , Nuriakhmetov R. , Kovalevsky A. , Lisitsyn A 
Published: October 2017

Abstract
The Bashkirian Formation within the Stepnoozerskoe oil field is represented by carbonate rocks with a complex geological structure characterized by high lateral and vertical heterogeneity. The reservoir temperature is about 23 deg C, the pressure does not exceed hydrostatic, the viscosity of oil in the reservoir conditions exceeds 200 cP, porosity and permeability of the reservoir vary widely.
In 2016, a pilot project to drill 2 multilateral wells on the Bashkir Formation was carried out; each well has 4 sidetracks (fishbones). Development of the reservoir with multilateral horizontal wells based on the simulation results allows to accelerate oil production, significantly improving the project economics, and the presence of horizontal sidetracks mitigates the risks associated with high lateral heterogeneity and ensures maximum contact of the wellbore with the reservoir.
To stimulate the inflow into the wells, it is necessary to conduct acid treatments. Two unique works were carried out in Russia with the use of a multilateral reentry system for detection and selective access into different boreholes. This system made it possible to orient and successfully enter the multilateral well with 4 open horizontal sidetracks for subsequent acid treatment. The treatment of the bottomhole zone was carried out with the help of self-diverting acidic compositions. In one of the wells, a buffer of hydrocarbon solvent, followed by steps of retarded hydrochloric acid injection and self-diverting acidic composition based on surface active agents was used. In another well, a dispersion of acid and solvent and a viscoelastic diverting acid on a polymer free base were used as a buffer.
In this paper, the authors describe the experience of stimulating multilateral horizontal wells and a comparative analysis of the results obtained.
Integrated Approach to Drilling, Formation Evaluation and Completion: Filanovskoye field Case Study
Authors: Rakitin M. , Shtepin D. , Golenkin M. , Shtun S. , Makhmotov A. , Rizvanov M. , Kuzakov V. , Novikov S. , Fitsner A. , Bulygin I. , Khakmedov A. 
Published: October 2017

Abstract
Whenever oil industry suffers another downturn companies fall back on conventional tools and methods. It is a valid move to cut down on spending and optimize cash flow. However, even in restricted times smart investments in valuable data can quickly redeem itself and bring extra barrels of production that fully justify the expense.
The following case study describes such case of smart utilization of unorthodox logging package that resulted in production optimization and better understanding of reservoir.
Ultra-Slim Cable-Deployed ESP Systems for Oil Field Development and Production
Authors: Gorbunov Dmitrii 
Published: October 2017

Abstract
An ultra-slim pumping system, Colibri ESP, 217 series, outer diameter 55 mm (2.17") and the technology for its application and deployment through 73 mm (2 7/8") tubing have been successfully developed and implemented. The equipment is deployed on a carrying cable without the need of involvement of a costly rig crew. Running to the setting depth of 2.5 km (8202 ft) takes only 1 hour.
This provides significant savings in terms of capital and workover costs, thus reducing total oil field development costs.
Identification of Refracturing Reorientation using Decline-Analysis and Geomechanical Simulator
Authors: Asalkhuzina G. F. , Davletbaev A. Ya. , Fedorov A. I. , Yuldasheva A. R. , Efremov A. N. , Sergeychev A. V. , Ishkin D. Z. 
Published: October 2017

Summary
Refracturing is used in many producing wells to improve well productivity, which falls over time. Well rate/pressure performance analysis indicates that in some cases a significant improvement of well productivity is observed after refracturing. Fracture reorientation is a possible reason why well productivity improves. It is important to run a forecast of fracture reorientation after refracturing. Completing this task will help develop an approach to a better selection of candidate wells for refracturing.
This paper shows results of numerical modeling of well rate and pressure performance before and after refracturing for cases when properties of the "old" fracture improved and for a case of fracture reorientation after hydraulic fracturing (HF), i.e., for two (the "old" one and the "new" one) perpendicular fractures. Results of numerical modeling made it possible to estimate the contribution that the improvement/recovery of the "old" fracture properties make into the well inflow as well as the contribution resulting from the existence of two fractures. Further, the production pressure analysis of field data for wells where repeated HF jobs were performed was made. The occurrence of fracture reorientation in all considered examples was checked in the geomechanical module. The analysis of the impact, which different reservoir values, Yung module have upon the possibility to redirect the fracture during refracturing, was performed in the geomechanical module, too.
Isokinetic Sampling of Multiphase Flow of Formation Fluids in Near-Critical Region
Authors: Muraviev Alexander 
Published: October 2017

Abstract
The representative sampling of formation fluid at the gas-condensate fields is very important, though, still unresolved task. Since the bottom-hole pressure drops rapidly below dew point in the course of well testing, the samples taken by the downhole samplers are not generally representative samples. The surface sampling of near-critical fluids by means of a test separator, as well as current no-separator methods of sampling from a multiphase mix are imperfect in many ways.
Proposed here is an alternative method of sampling from multiphase flow meter measurement line, where the well is first brought on to stable production corresponding to formation fluid recovery with maximum gas-condensate factor. After that a multiphase stream of fluids will be allowed to pass through an effective mixer (emulsifier) to attain isokinetic flow, which will be followed by taking samples under pressure into high pressure vessels whose thermodynamic conditions correspond to conditions in the sampling line. Such technology will ideally work with any in-line multiphase flowmeters, since these measuring devices do not require fluid separation, while the accuracy of measurements in a uniform mix increases. The sampling technology implicates availability of three components: choke manifold, emulsifier installed in a bypass line, and multiphase flow meter. The proposed method of sampling non-separated mix from multiphase flow meter measurement line is simple for implementation, economically efficient and helps solve the task of obtaining representative formation samples of near-critical fluids. It can be used as an alternative to the downhole and separator sampling and is suitable for testing gas-condensate and oil wells. The compactness, information capacity and productivity of the system, including multiphase flow meter with taking samples, provides new opportunities for maritime testing of wells and, in particular, at the Arctic shelf.
Interpretation of Indicator Studies of Multistage Fracturing
Authors: Mazo A. B. , Sattarov R. I. , Khamidullin M. R. , Potashev K. A. , Trifonov T. V. 
Published: October 2017

Abstract
The paper presents a technique for interpreting indicator studies of multi-stage hydraulic fracturing (MSHF) on horizontal wells (HW), based on numerical modeling of indicator transfer in the near-well zone. Two problems are distinguished in the simulation: the direct problem of calculating the pressure, water saturation, and concentration of the indicator at the given parameters of the well during the injection of the indicator and the further operation of the well; the inverse problem of selecting the parameters of the hydraulic fractures (geometry and permeability) from the measured curves of the indicator removal after the transfer of the well to the withdrawal. In the course of solving the inverse problem, the separation of the total water and oil rates along the fracturing intervals is determined.
The direct problem is based on the mathematical model of a three-dimensional two-phase multicomponent filtration taking into account diffusion and sorption in the region of drainage of HW with MSHF. The case of water-soluble indicators is considered in the model. In the numerical implementation of this model, we use structured finite-volume grids with significant condensation near the fractures and wells, as well as fast-acting algorithms for the end-to-end solution of the problem for pressure in the reservoir and fractures and an explicit-implicit scheme for solving the tracer transfer problem.
The solution of the inverse problem minimizes the deviation of the calculated tracer output curves, total production rate and water cut from the corresponding observation data. The minimization is performed iteratively (by modifying the Broyden-Fletcher-Goldfarb-Shanno method with the limitation of the memory used).The direct problem is solved at each iteration. In this case, a simplified model is used that takes into account the rectilinear-parallel structure of the filtration flow in the penetration region of the tracer, which makes it possible to expand the three-dimensional problem into a series of one-dimensional ones and substantially accelerate the calculation.
The proposed algorithm for the interpretation of indicator studies is demonstrated by the example of processing real data obtained during the 4-interval transverse MSHF on a HW of a productive reservoir represented by the interlacing of sandy-siltstone rocks with dense interlayers of clays belonging to the terrigenous deposits of the Achimov strata of Western Siberia. The length of the horizontal section of the wellbore was 820 m. The water-soluble indicators DCT-WS-01, DCT-WS-03, DCT-WS-04, and DCT-WS-07 were used as tracers. The main hydraulic fracturing was preceded by mini-fracturing. The fractures contained 80 tons of ceramic proppant for the first three stages and 60 tons for the fourth stage. The average half-length of the hydraulic fractures was 100 m, height - 50 m, and thickness - 4 mm.
Estimation of Reservoir Pressure from the Sensor Data Before and After Injection Tests in Low-Permeability Formations
Authors: Bobreneva Yu. O , Davletbaev A. Y. , Makhota N. A. , Kamalova Z. K. 
Published: October 2017

Abstract
One of the most promising and less costly methods to determine formation pressure is pressure curve analysis after injection tests (displacement, minifracturing, DFIT) during hydraulic fracturing. When pressure performance is interpreted after the fracture closure (ACA), for instance, by Nolte method, it is not always possible to diagnose a flow mode (pseudo-linear, pseudo-radial) and to determine formation pressure and reservoir parameters. The paper discusses one the methods of obtaining a "rough" estimate of the formation pressure value in cases with "undertracked" pressure builup curves after frac injection tests.
When ACA methods are used to diagnose flow modes after the fracture closure, and when pressure drawdown test is not long enough, it is impossible to determine formation pressure for certain. The paper analyzes bottomhole pressure performance for the time periods before, during and after hydraulic fracturing. The offered approach is an addition to Nolte's (analysis after fracture closure) and Horner's methods. The main advantage of this approach to formation pressure evaluation is that it does not require a complex interpretation or analyzing of bottomhole pressure performance using special software - a visual analysis of the pressure chart received from downhole pressure gauges is enough.
Complex Distributed Permanent Monitoring System for Horizontal Wells. Noviy-Port Field Case Study
Authors: Ipatov A I , Kaeshkov I S , Krementskiy M I , Bazhenov D U , Buyanov A V , Panarina E P , Figura E V , Klishin I A , Nukhaev M T 
Published: October 2017

Abstract
This paper presents the results of long-term monitoring based on distributed fiber-optic sensing in producing horizontal well. The reported data illustrates high informative value of non-stationary temperature logging used to control well operation, inflow profiling and formation depletion.
Evolution of Approaches to Oil Rims Development in Terrigenous Formations of Eastern Siberia
Authors: Levanov A. , Kobyashev A. , Chuprov A. , Yashchenko S. , Musin R. , Chirgun A. , Svyashchenko A. , Grinchenko V. , Ovchinnikov A. , Burdakov D. , Zimin S. 
Published: October 2017

Abstract
Evolution of approaches to the development of oil rims is presented, based on the results of full-scale development of large oil and gas fields of East Siberia (Verkhnechonskoye, Srednebotuobinskoye, and Yaraktinskoye) put into production, in which a significant share of oil reserves (29% to 69%) is concentrated in the areas having a gas cap on top (figure 1).
Production from these fields is confined to clastic reservoirs which in a number of key parameters are geologically similar, and at the same time in other key parameters are substantially different.
A distinctive feature of the publication is the description of the process of change of solutions for the development of oil rims, where simulation models were used as the main tool of investigation.
All available technologies and the efficiency of their combined application were assessed for each reservoir, taking into account their unique geological structure (areal and crosssectional heterogeneity, reservoir permeability, presence of an aquifer).
The value of this work lies in systematization of practical experience of designing the development of, and operating the oil rims of the three large oil and gas fields in East Siberia, which forms a knowledge base for the development of the second stage oil and gas fields of the region. The accumulated pool of technological solutions adopted for implementation covers a range of various geological conditions of the productive clastic reservoirs.
Information Support of Field Development Control and Analysis in LUKOIL Research and Development Complex
Authors: Chertenkov MIkhail V. , Zolova Irina V. , Pryanichnikova Elena V. , Vidyakin Vasiliy V. 
Published: October 2017

Abstract
This article presents new functional capabilities and prospects of development of the corporate analytical system used in the LUKOIL PJSC research and development complex for solving the problems of operational monitoring of the process of development of oil and gas fields. The system provides users with unified access mechanisms and toolkit for analysis of field information on the level of affiliated oil and gas companies, regional production divisions, fields, development targets and elements, wells. The system provides performing of comprehensive assessment of the status of site development based on analysis of oil production capabilities, production and reserves indicator behavior, condition of well stock, realization of the set rates of oil production. The article contains the brief description of the basic principles of system building and new functions of the development target status monitoring subsystems, analysis of well data, map documents and results of geological and reservoir simulation modeling.