bluuebunny/crossref_metadata_2025 huggingface dataset:
La nueva generación de Reformas Procesales Penales en Latinoamérica
Authors: Vargas Viancos Juan Enrique
Published: October 2015

Prácticamente en toda América Latina, los procesos de recuperación democrática experimentados vinieron acompañados de reformas a sus sistemas de justicia. El proceso más consistente ha sido el de transformaciones a la justicia criminal. Inicialmente concentrado en la mejora de las garantías procesales, a lo que se le uniría más adelante el interés de dotar al sistema de justicia criminal de mayores niveles de efectividad en el esclarecimiento y sanción de delitos…
La pandilla proxeneta : violencia y prostitución juvenil en Centroamérica
Authors: Rubio, Mauricio
Published: October 2015

En este artículo se presentan resultados de encuestas de autorreporte de conductas, aplicadas a jóvenes entre 13 y 19 años en Centroamérica. Adicionalmente se contrastan las principales hipótesis sobre violencia juvenil en la región y se encuentra que la pobreza no es condición ni necesaria ni suficiente de vinculación de los jóvenes a las pandillas, que aparecen como agrupaciones que concentran e impulsan la violencia juvenil. Se argumenta que más que incentivos económicos la pandilla ofrece a los jóvenes la posibilidad de acumular poder e incrementar su actividad sexual. La violencia sexual que la pandilla ejerce contra las mujeres, en un entorno en extremo machista, aparece como detonante de la prostitución femenina. Cual proxenetas, las pandillas de barrio, más que las mafias internacionales de traficantes, usan, promueven y protegen la prostitución adolescente.
Crónica roja en los medios de comunicación ecuatorianos : ¿un problema de seguridad ciudadana?
Authors: Pontón Cevallos Jenny
Published: October 2015

En el presente artículo, la autora analiza la ‘espectacularización’ mediática en el tratamiento de la violencia y sus ulteriores consecuencias en la calidad de vida de la población ecuatoriana. A partir de una entrada teórica y de la presentación de cifras y datos, Pontón atribuye a la exagerada difusión de la criminalidad y la delincuencia como elemento para capturar sintonía, una distorsión en la percepción social de la seguridad ciudadana, precisamente por la relación que existe entre realidad social e información mediática.
Comparativo
Authors: Urvio Urvio
Published: October 2015

Comparativo 
Historia y violencia : una necesaria (de)construcción
Authors: Carrión M. Fernando
Published: October 2015

La violencia ha estado siempre presente en América Latina, desde sus orígenes hasta el día de hoy. Sin embargo, eso no quiere decir que su dinámica (lógica) y expresión (tipos) a lo largo del tiempo hayan sido siempre la misma; por el contrario, lo que ha existido es un proceso histórico donde se han ido moldeando sus particularidades, al extremo que la presencia actual no es otra cosa más que su consecuencia. Además hay que tener en cuenta que no sólo la violencia tiene una condición histórica, sino también su reverso: la seguridad, porque las dos son parte de una ecuación compleja donde la una (violencia) y la otra (la seguridad) son dos caras de una misma moneda.
Comparativo
Authors: Flórez Holguín Lorena
Published: October 2015

Comparativo 
Sicariato y crimen organizado : temporalidades y espacialidades
Authors: Pontón C. Daniel
Published: October 2015

El homicidio es el indicador favorito, y más usado por académicos y hacedores de políticas públicas, para conocer el nivel de inseguridad y violencia de una determinada sociedad. De hecho, se lo asume como elemento comparativo para mirar la incidencia de este fenómeno a nivel territorial y espacial, con el fin de construir categorizaciones que indiquen el grado de complejidad de esta problemática. Sicariato (hombre daga en su significado etimológico) es el nombre usado para describir un tipo de homicidio cualificado (asesinato), y agravado por el cobro de una remuneración económica a cambio de dar el servicio de matar a otra persona; este fenómeno no siempre se desarrolla en ambientes de altos niveles de homicidio y criminalidad, como se suele creer.
La emergencia del problema delincuencial en un conjunto habitacional de población relocalizada
Authors: Brites Walter Fernando
Published: October 2015

El propósito de este artículo es analizar la conformación de escenarios de gestión asociada, Gobierno/ciudadanía, a fin de solucionar, entre otros problemas, la inseguridad en un conjunto habitacional de población relocalizada, en la ciudad de Posadas (Argentina). El análisis gira en torno a los problemas delictivos desencadenados por crecientes situaciones de marginalidad, y los intentos de solución a partir de las mesas interactorales entre vecinos del barrio y actores gubernamentales.
VULNERABILIDADE AOS IMPACTOS AMBIENTAIS DA BACIA HIDROGRÁFICA DO RIO CAUAMÉ EM DECORRÊNCIA DA EXPANSÃO URBANA E USO PARA LAZER EM SUAS PRAIAS
Authors: Oliveira Juliana da Silva , Carvalho Thiago Morato de
Published: October 2015

Esta pesquisa teve como objetivo caracterizar temporalmente o uso e cobertura da bacia hidrográfica do rio
Cauamé, no ano de 2014 e análise visual para 1943 e 1975, para identificar as vulnerabilidades sócioambientais com base no padrão de uso destinado ao lazer nas praias do rio Cauamé. As etapas metodológicas
foram baseadas em técnicas de sensoriamento remoto/geoprocessamento que foram utilizadas para a
classificação do uso e cobertura da terra, perfil longitudinal, declividade e hipsometria; idas a campo, para a
identificação dos pontos vulneráveis a impactos ambientais e sua caracterização. A bacia foi compartimentada
com base em critérios geomorfológicos em três divisões: alta, média e baixa bacia as quais representem o alto,
médio e baixo curso do rio Cauamé. Esses três compartimentos foram segmentados em quatro tipos de
padrões de drenagem: retangular, paralelos, dendríticos e sub-dendríticos. Foram caracterizadas seis praias
para o lazer: Praia do Caçari, Praia da Polar, Praia do Curupira, Banho da Ponte, Banho do Caranã e Banhoda
Cachoeirinha. Os resultados desta pesquisa ajudarão a traçar o perfíl do meio físico, como o padrão de uso e
cobertura da bacia do rio Cauamé, e servir de base para a caracterização das áreas destinadas ao lazer e seus
respectivos impactos ambientais. Informações importantes para o gerenciamento/planejamento urbano e de
áreas úmidas, assim como compor bases iniciais do entendimento dos aspectos hidrogeomorfológicos de
Roraima.
La convergencia tecnológica en las aulas virtuales de la Facultad de Estudios a Distancia de la Universidad Militar Nueva Granada (UMNG)
Authors: Colorado Ordónez Paula , Cogollo Rincón José Guillermo
Published: October 2015

El presente trabajo analiza si la comunidad académica de la Facultad de Estudios a Distancia está preparada para una convergencia tecnológica en cuanto a los contenidos virtuales de las asignaturas. El objeto del artículo es estudiar la
viabilidad de ofrecer todos los contenidos virtuales a través de dispositivos móviles y, de esta manera, tener mayor cobertura para los procesos de formación.
Para este estudio se encuestaron docentes y estudiantes del aula virtual de la Facultad de Estudios a Distancia, se efectuó análisis cuantitativo de la información recolectada con el uso de herramientas tecnológicas y se tomaron los elementos motivo de estudio, para hacer el análisis correspondiente. Los estudiantes y docentes mostraron que tienen habilidades en el uso de dispositivos electrónicos, móviles y entornos virtuales, las cuales se pueden reflejar en el entorno académico para conseguir una educación de mayor calidad.

Palabras clave: convergencia, dispositivos móviles, aula virtual, contenidos virtuales.
Diagnóstico de las competencias lectoescritas en estudiantes de posgrado
Authors: Triana Murillo Luz Marina
Published: October 2015

Este artículo resulta de la investigación "Didáctica para el desarrollo de las competencias lectoescritas en estudiantes de posgrado", el cual aborda la problemática del nivel de apropiación de las competencias en lectoescritura por parte de estudiantes de educación terciaria, en posgrado. La investigación determina las causas del índice de no graduados en una institución de Educación Superior y el estado de las competencias en lectoescritura de los estudiantes de la especialización de Logística Aeronáutica a través de un estudio de caso, en el cual se evidencia que el 85% de la muestra se encuentra en niveles de regular a deficiente, clasificando a los estudiantes en el nivel A1 de competencia en el dominio de su lengua materna de acuerdo con los estándares del Marco Común Europeo
Characterization of a novel laccase purified from the fungus Hohenbuehelia serotina and its decolourisation of dyes.
Authors: Xu Yingyin , Lu Yuxiao , Zhang Rui , Wang Hexiang , Liu Qinghong
Published: October 2015

A novel laccase was purified from the white rot fungus, Hohenbuehelia serotina, to investigate the applications of this laccase in the decoloration of various dyes. SDS-PAGE revealed a single band of this laccase corresponding to a molecular weight of approximately 57.8 kDa. The enzyme showed activity towards several substrates, the most sensitive of which was 2,2'-Azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS). The highest enzymatic activity using ABTS as a substrate was observed at pH 6.8 and 30°C. The enzyme activity was found to be significantly enhanced in the presence of Zn(2+) ions and inhibited by Fe(2+) ions. Moreover, SDS and β-mercaptoethanol were inhibitory, and inhibition by L-cysteine was observed while EDTA and DMSO had almost no inhibitory effect. The laccase could effectively decolorize seven different dyes within 30 minutes at 40°C.
Fisheries and biodiversity benefits of using static versus dynamic models for designing marine reserve networks
Authors: Brown Christopher J. , White Crow , Beger Maria , Grantham Hedley S. , Halpern Benjamin S. , Klein Carissa J. , Mumby Peter J. , Tulloch Vivitskaia J. D. , Ruckelshaus Mary , Possingham Hugh P.
Published: October 2015

Marine reserves are widely used to manage for the potentially conflicting objectives of conserving biodiversity and improving fisheries. The fisheries and conservation benefits of alternative reserve designs would ideally be assessed using dynamic models, which consider spillover of fish and larvae to fished areas, and the displacement of fishers to unprotected sites. In practice, however, decisions about the location of marine reserves generally rely on cheaper and faster static models. Static models analyze only spatial patterns in habitats, and typically assume fisheries profits are reduced by the amount that was generated in areas designated as reserves. To help determine the benefits of developing dynamic fisheries models, we assessed how well static models estimate costs of reserve systems to fisheries and how outcomes from reserves designed using either static or dynamic models differ. We tested these questions in two case studies, the network of marine protected areas in southern California, USA and the proposed Tun Mustapha Marine Park in Malaysia. Static models could either under or over‐estimate the cost of reserve plans to fisheries, depending on the relative importance of fisher movement and larval dispersal dynamics. Despite the inaccuracy of static models for estimating costs, reserves designed using static models were similar to those designed with dynamic models if fisheries were well managed; or larval dispersal networks were simple. If larval networks were complex or there was overfishing, dynamic models generated substantially different reserve networks from static models, which improved conservation outcomes by up to 10% and fishing profits by up 20%. The time‐scale of management was also important, because only dynamic models accounted for larval dispersal, so could find reserves that maximized the long‐term benefits of larval spillover. Our case studies provide quantitative support for the assertion that static models can be useful for planning marine reserves for short‐term objectives in well managed fisheries, but are not reliable for evaluating the relative costs of reserves to fisheries.
Effects of climate change on long‐term population growth of pronghorn in an arid environment
Authors: Gedir Jay V. , Cain James W. , Harris Grant , Turnbull Trey T.
Published: October 2015

Climate often drives ungulate population dynamics, and as climates change, some areas may become unsuitable for species persistence. Unraveling the relationships between climate and population dynamics, and projecting them across time, advances ecological understanding that informs and steers sustainable conservation for species. Using pronghorn (Antilocapra americana) as an ecological model, we used a Bayesian approach to analyze long‐term population, precipitation, and temperature data from 18 populations in the southwestern United States. We determined which long‐term (12 and 24 months) or short‐term (gestation trimester and lactation period) climatic conditions best predicted annual rate of population growth (λ). We used these predictions to project population trends through 2090. Projections incorporated downscaled climatic data matched to pronghorn range for each population, given a high and a lower atmospheric CO2 concentration scenario. Since the 1990s, 15 of the pronghorn populations declined in abundance. Sixteen populations demonstrated a significant relationship between precipitation and λ, and in 13 of these, temperature was also significant. Precipitation predictors of λ were highly seasonal, with lactation being the most important period, followed by early and late gestation. The influence of temperature on λ was less seasonal than precipitation, and lacked a clear temporal pattern. The climatic projections indicated that all of these pronghorn populations would experience increased temperatures, while the direction and magnitude of precipitation had high population‐specific variation. Models predicted that nine populations would be extirpated or approaching extirpation by 2090. Results were consistent across both atmospheric CO2 concentration scenarios, indicating robustness of trends irrespective of climatic severity. In the southwestern United States, the climate underpinning pronghorn populations is shifting, making conditions increasingly inhospitable to pronghorn persistence. This realization informs and steers conservation and management decisions for pronghorn in North America, while exemplifying how similar research can aid ungulates inhabiting arid regions and confronting similar circumstances elsewhere.
Advancing Normal Birth
Authors: Lothian Judith
Published: October 2015

In this column, the associate editor of The Journal of Perinatal Education provides an overview of research on the benefits of promoting and protecting the normal, physiologic processes of childbirth and the risks of interfering with those processes without clear medical indication. The associate editor also describes the contents of this issue, which offer a broad range of resources, research, and inspiration for childbirth educators in their efforts to promote, support, and protect natural, safe, and healthy birth.
Exploring Fathers’ Role in Breastfeeding Practices in the Urban and Semiurban Settings of Karachi, Pakistan
Authors: Mithani Yasmin , Premani Zahra Shaheen , Kurji Zohra , Rashid Shehnaz
Published: October 2015

This study explored fathers’ perceptions about breastfeeding infants. A qualitative exploratory study design was used. Study setting was urban and semiurban areas of Karachi, Pakistan. In-depth interviews were conducted with 12 fathers. The following themes emerged from the data collected: knowledge and awareness and enabling and impeding factors. Most fathers seemed eager to get involved and assist their partners in proper breastfeeding practices because they believed that doing so is in accordance with their faith. Fathers felt that adequate support from their family members and employers could enable them to encourage their partners to initiate and maintain exclusive and optimum breastfeeding practices. Exploring fathers’ perception regarding breastfeeding in the context of Pakistan is still a new field of study.
Features of Solutions Drilling Problems While Drilling With OBM
Authors: Figilyantov A. , Iliasov S. , Okromelidze G. , Garshina O. , Chugaeva O.
Published: October 2015

Complications during well drilling is one of the most expensive items. Sometimes, losses of companies for solving drilling problems are comparable to the cost of new well construction.

The most common and one of the cheapest ways to solve the drilling problems is cement plug. Cement plug operations are used to eliminate a circulation lost, consolidation of unstable rocks, kill part of the wellbore or sidetrack, to make the support for the re-drilling the hole or sidetrack.

Particular difficulties arise while cement plug setting in environments of the oil-based mud (OBM). The using of OBM is necessary because of the complexity of the spatial distribution and inclination of wells. OBM have a number of advantages compared water-based drilling fluids. However, OBM using does not guarantee the complete absence of complications and accidents.

In the Perm region widespread using of OBM were began in 2008. Attempts to eliminate complications during drilling with the use of OBM, setting cement plugs have not been successful, in most cases.

The article presents the results of laboratory tests of grouting material based on Portland cement class G for cement plug operations among OBM without special system of spacers and the experience of practical application of the material.
How an Integrated Services Approach Significantly Reduced Well Construction Time at Kuyumbinskoe Field in Eastern Siberia, Russia
Authors: Ignatiev Nikolay , Nedelko Pavel , Dementyev Alexander , Malkevich Liubov , Mazaev Konstantin
Published: October 2015

The Kuyumbinskoe field is a remote location, situated in the central part of Eastern Siberia 1000 km to the North from the nearest city of Krasnoyarsk (Figure 1). Weather conditions in this region are severe. Project logistics are complicated. There are no roads available for nine months of a year. Heavy load transportation is only possible in the winter period via ice roads. During the rest of the time, the only means of transportation are helicopters.

The Kuyumbinskoe field is known for its intensive oil exploration activity. The oilfield has been proven for its strategic importance for meeting production quotas to China. However, only two horizontal wells were drilled in the past with maximum horizontal drain lengths of 300 m. One of the main geological challenges is the presence of extensive natural fractures in each section of the well. Drilling through those naturally fractured formations leads to wellbore stability issues and severe or total drilling fluid losses especially in production formation which are extremely difficult to manage.

In 2013 it was determined that an Integrated Services approach would be the best model to define optimum technologies, gain necessary experience of horizontal drilling, improve well construction efficiency and to update geological model for further field development. This approach was vital for the successful fast tracked mobilization of materials and equipment to this remote field by winter road and without the need of further helicopter delivery. Six horizontal wells with pilots and more than 700 m of horizontal drain were drilled between April 2013 and November 2014 wherein 100% of the geological targets and drilling objectives were achieved.

This paper will demonstrate how the Integrated Services approach, collaboration, risk analysis and contingency planning, special equipment, technologies and innovations were applied for successful accomplishment of the project objectives. Drilling efficiency was increased by 60% in comparison with the previous experience in this field with complex geological conditions. The first wells were successfully put into production ahead of the plan.
Developing High Resistant Cement Systems for High-pressure, Hightemperature Applications
Authors: Tabatabaee Moradi Seyyed Shahab , Nikolaev Nikolay Ivanovich , Naseri Yasin
Published: October 2015

Worldwide growing in hydrocarbon demand is driving the oil and gas companies to explore areas with more hostile conditions, such as high-pressure, high-temperature conditions. By increasing the number of projects in these conditions improved technology, material selection and testing procedures are required to overcome the challenges. One of the main reasons, causing the cement systems to fail in these environments, is concentration of stresses inside the wellbore induced by downhole changes of temperature and pressure. Therefore the objective of this work is to develop a high resistant cement system. The stress resistant cement systems in this study are produced by adding silica sands and silica flour to the dry cements. To study the effect of temperature and pressure on strength properties of set cements all samples are cured at elevated temperatures and pressures. Also the effect of curing time on the strength properties are investigated. The results show that the developed cement systems with silica flour show more strength properties, due to its microstructure properties. In these cement systems, the number of cracks and micro fracture are less than the systems with silica sand due to the fine particles size of silica flour. The cracks and fractures inside the failed set cement systems serve as pathways for formation fluids to the surface, and thus reducing the life of the well. Increasing the concentration of silica sand and silica flour will increase the strength properties but at the same time it strongly affects the other properties of cement slurry. So additives have been used to adjust other essential properties of cement systems.
Formation Damage due to Drilling and Well Completion: Extrenal Cake Formation and Stabilisation
Authors: Kalantariasl A. , Bedrikovetsky P. , Vaz A. S.
Published: October 2015

The external filter cake build-up with its final stabilization has been widely reported for drilling fluid invasion and return permeability phenomena, frormation damage by completiuon fluid, waterflooding in oilfields, drilling, produced water re-injection and disposal of produced water in aquifers. The brief overview of the models for cake formation and stabilization is presented. We derive the mechanical equilibrium equation for stabilized cake accounting for electrostatic force and for varying permeate force factor. The main empirical parameter of the model, highly affecting the stabilized cake prediction is the lever arm ratio for the particle on the cake surface. The lever arm ratio was calculated from laboratory cross-flow filtration experiments and from well injectivity data. It was also determined from Hertz's theory for the elastic particle deformation on the solid cake surface. Good agreement between the results validates the developed mechanical equilibrium model with the lever arm ratio determined from the elastic particle deformation theory.
Cased Hole Production Testing with Extended Spacing Wireline Formation Testers
Authors: Charupa M. , Khaziev M. , Blinov V. , Weinheber P. , Oreshko I. , Goitia V. H. , Eslami B. , Arnez R.
Published: October 2015

Wireline formation testing in open hole can yield robust and reliable information about reservoir fluid type and productivity. However, operational or logistical concerns can sometimes preclude gathering a full open hole formation tester data set. In this case the operator is left to either forgo the information or acquire the data in cased hole. Perforating and production testing in cased hole can be time consuming and expensive especially when there are multiple layers to be tested. This can be mitigated by using wireline formation testers (WFT) in cased hole to test individual layers, but these testers have traditionally been limited in their possible interval length. In this paper we discuss cased hole wireline formation testing with a unique configuration of the WFT that allows testing intervals much greater than previously possible.

Wireline formation tester tools with straddle packers are typically limited to about 1-m spacing between the packers. With special adaptors spacings up to 3 m have been accomplished. However, when perforated intervals are longer than this the straddle packer is not an option: it is usually inadvisable to set the elements across perforated casing and cracks in the perforated cement can make the fluid typing ambiguous. This paper discusses a method whereby two separate straddle packer tools are combined and allow a significantly longer interval to be tested.

We present a case study where the extended interval was tested and flowed for several days with the formation tester and a confident determination of fluid type performed. Additionally, a long build-up time enabled us to derive a robust estimation of permeability. The operation was concluded in three days versus the ten days of rig time that would have been expected for a cased hole production test. We also show how this method can be extended to longer intervals in both open and cased hole. We conclude that this method is should be considered for zones that could not be tested in open hole but are not worthy of a full production test in cased hole.

Although cased whole WFT operations with straddle packers have been reported in the literature this is the first instance of a double WFT tool arrangement that allows testing layers of significant perforated length. Operational guidelines and environmental limitations are also discussed.
Opportunities for Implementing Cold Water for Fracturing Services in Western Siberia
Authors: Mikhaylov D. Y. , Vernigora D. E. , Olennikova O. V. , Gromovenko A. V. , Mathur A.
Published: October 2015

Hydraulic fracturing is one of the major techniques in modern well stimulation practices. The purpose of the current contribution is to gain novel insights on utilization of cold water for fracturing services in Western Siberia aiming to reduce non-productive time and price while maintaining excellent quality of service delivery. The study covers the hydration of non-modified guar gum and borate crosslinking in cold water conditions, the associated risks and plausible benefits are also considered.

Among all fracturing services, conventional borate crosslinked guar gum fluids remain the most widely utilized due to their economical profitability, availability, ease of viscosifying and handling. The reduced temperature of water affects the guar swelling and hydration during linear gel preparation and influences the crosslinking reaction rate for delayed borate systems. One of the obvious drawbacks of the guar-based fracturing fluids is the necessity for a water heat-up process, especially during winter period. Within the scope of present study we are discussing the opportunities and perspectives of non-modified guar fluids for cold water fracturing applications.

This original research details the comprehensive laboratory evaluation and thorough theoretical study, which presents a variety of fracturing fluids available to hydrate and crosslink in water temperatures starting from 5 degrees Celsius. It was revealed that the hydration of guar polymer (loading 3.6 kg/m3) in water varies between 82-88% at 5 degrees Celsius. The optimized borate-crosslinked fluids provide viscosity greater than 400 cP at 96 degrees Celsius. The versatility of proposed fracturing fluids was proven by exceptional viscosity recovery to 400 cP in less than one minute after high shear regime in the range of 10-50 degrees Celsius, simulating the fluid behavior in near-wellbore area at ambient temperature.

The scope of work included the development of cold water implementation criteria and evaluation of possible associated risks, e.g. the additional cooling effect upon contact with proppant. The results presented in the current work pave the way for implementation of conventional borate-crosslinked guar gum fluids for cold water fracturing. Without significant price increase the proposed approach allows to decrease 30% of non-productive time and reduce heating expenses. The approach is significantly beneficial in areas exposed to cold winter conditions like Russia, Alaska or Canada.
Analysis of Nuclear Well-Logging Tool Response Sensitivities Using Monte Carlo Modeling
Authors: Banzarov B. , Velker N. , Vinokurov A. , Simonov N.
Published: October 2015

Designing nuclear well-logging equipment encounters various challenges, many of which are associated with the optimization of the tool for maximum sensitivity to a desired parameter. To estimate the efficiency of a particular detector material and various design features, the tool developers perform complex research using data from test measurements and mathematical modeling. For neutron-logging tools, the design is aimed at optimizing sensitivity to either the formation neutron porosity or to the cross-section of neutron absorption in the formation. The larger fraction of the tool response comes directly from the investigated formation layer, the more precisely the parameters of interest are evaluated. Consequently, estimating and minimizing the borehole and the casing contributions to the tool response while keeping the count rate high is an important and challenging problem.

To solve the problem, the authors propose a method to estimate the sensitivity of a tool to various areas of the environment. In the proposed approach, the detector responses are calculated as the sum of contributions from various regions of the medium. This method enables, for example, comparison of the contributions to the tool response coming from the well, from the tool and from the investigated formation layer.

To calculate the contribution, the Monte Carlo methods are used. To perform Monte Carlo simulation, the Geant4 software package was used. The package provides a method to access the complete information about the simulated neutron trajectories, including time, position and energy change at each neutron interaction with the atoms of the medium. Another valuable option of the software is its ability to incorporate a variety of estimators that utilize the detailed information about the trajectories.

The method proposed in this work enables the estimation of the sensitivity of the tool to measured parameters of formation and optimization of the tool configuration from the estimation. As a concrete illustration of how the method works, an analysis of two modifications of neutron logging tools is presented. One has a chemical source; another one has a neutron generator as a source. In the studied task, the sensitivity to a selected space domain is related to a fraction of time the neutrons spend in this domain relative to the total time the neutrons travel between thermalization and registration moments.
Influence of Iron Pentacarbonyl on Catalytic Aquathermolysis of Heavy Oil: Changes of Oil's Parameters and Formation of Magnetic Nanoparticles
Authors: Galukhin A. V. , Erokhin A. A. , Gerasimov A. V. , Eskin A. A. , Nurgaliev D. K.
Published: October 2015

In this study, we investigated the influence of iron pentacarbonyl, as oil-soluble catalyst precursor, on aquathermolysis of heavy oil of the Ashal'cha field. We estimated catalytic properties by applying SARA and elemental analysis, measuring viscosity, as well as evaluating changes in molecular weight distribution of high molecular weight components of the oil. It was found that presence of iron pentacarbonyl leads to an improvement of oil properties, resulting in decrasing of average molecular weight of resin fraction. It was shown that iron pentacarbonyl forms magnetic nanoparticles consisting of magnetite and pyrrhotite during the steam treatment of heavy oil. The properties of magnetic nanoparticles by various physical and physicochemical methods were also studied.
Modeling of Completion Installation That Meets Modern Conditions of Work Performance
Authors: Zhuravlev Oleg , Shchelushkin Roman , Shadsky Alexey , Prokopcev Roman
Published: October 2015

An analysis of modern completions processes shows the necessity of a numerical three-dimensional modeling of dynamic processes occurring during the completion installation into the well. An actual task is to develop high-quality software package takes into account all the interests of the customer, such as risk not reaching the target depth, buckling, and adapted for the end user.

This manuscript describes the mathematical model used in specialized software environment for modeling the running of completion, liners, casing, drillstring, multistage fracturing and other downhole equipment. The mathematical apparatus included into the software, describes the following calculations: hook load during running and pulling out, buckling analysis, taking into account stiffness of the liner, the stress distribution in the column, the geometric fitting of the elements of completion, completion running with rotation and with "floating" method.

The presented solution is able to predict potential problems during the completion running into the well and can reduce the risks and optimize the installation process.

The software is also a good tool for peer reviews to optimize the characteristics of pipes, etc. used in the well completion.
A Novel Tool to Improve Rate of Penetration–Down-hole Drilling String Absorption & Hydraulic Supercharging Device
Authors: Zhang Hongning , Guan Zhichuan , Liu Yongwang , Xu YuQiang
Published: October 2015

On the basis of the study on drill string vibration rules in vertical well drilling and the idea of transformation of drill string vibration energy to drilling fluid hydraulic energy, a novel tool, down-hole drill string absorption & hydraulic supercharging device (DSAHSD), is designed to further improve the rate of penetration (ROP). The DSAHSD combines the advantages of reducing the axial vibration of the drill string and generating more than 120 MPa ultra-high pressure jet to effectively assist rock breaking. When the drilling fluid flows through this tool, part of the drilling fluid will be modulated to the ultra-high pressure jet by periodic compression of piston drove by drill string vibration. During this process, the ultra-high pressure jet ejected through ultra-high pressure nozzle that fixed on the bit edge in bottom hole. Because of hydraulic auxiliary rock breaking of the ultra-high pressure jet, the ROP will be improved. This tool has been applied to more than 40 wells in four oil fields throughout China. The results show that the maximum density of the test drilling fluid is 1.9g/cm3, the maximum footage is 1480m, and the operation time of the tool is more than 200 hours. Furthermore, the average ROP was increased by approximately 11% to 831%. In conclusion, the DSAHSD has the characteristics of a simple structure, has a long lifetime, is able to adapt well with existing drilling equipment, and can provide a safe and efficient drilling technique for deep wells. In addition, a novel design idea of down-hole hydraulic booster was proposed, so this is a major breakthrough of down-hole supercharging technique.
Pressure Depletion Optimization and Increase of Oil Production by Well Test and Decline Analysis
Authors: Morozovskiy Nikita , Melnikov Sergey , Krichevskiy Vladimir , Feoktistov Roman CJSC
Published: October 2015

The paper describes the use of pressure monitoring of producing and injecting wells for estimating the effectiveness of pressure maintenance system (PMS). On the first stage of forming such system, due to low replacement rate there is no traditional signs of effectiveness: producing rates increase, bottomhole pressures raise etc. In this case decline analysis based on permanent telemetric downhole gauge system, can be effective estimation tool. The authors have proved the effectiveness of pressure maintenance system on one of the oil fields of Orenburg region.

Basing on pressure and rate analysis, hydrodynamic models were built in Ecrin software of Kappa Engineering of producing wells, placed right next to injection wells. Results of long-term well tests and decline analysis were the base of estimation approach.

Based on complex analysis of producing wells, placed near first injection clusters, paper shows the stable influence of injection. Solving of this problem would be impossible without developing an online well parameters monitoring system on the field. The use of stationary telemetric system helps solving problems not only in wells or clusters scale, but also for the whole field.

This work again proved the effectiveness of equipping wells with telemetric monitoring systems of all parameters. It provides the possibility to make fast and effective decisions of field development and maintain base production rates. The work shows significant value of hydrodynamic development monitoring as for specific wells and for the whole field.
Optimizing Fractured Horizontals Performance with Well Test Data
Authors: Krichevskiy V. M. , Morozovskiy N. A. , Gulyaev D. N. , Bikkulov M. M.
Published: October 2015

Paper presents multi-fractured horizontals performance analysis in case of low-permeable formation. The puppose of the analysis is to suggest a method of optimizing multi-frac parameters (such as number of fracs, fracs spacing, Xf etc.) in different geological conditions. Paper describes an algorithm of estimating main formation and well characteristics and forecasting future production. In addition, an approach to multi-frac design optimization for new wells is shown.

The main tools of well performance analysis are production logging, well testing, decline analysis and simulation. Authors have performed all these survey types analyzing multi-fractured wells behavior. Authors have developed and successfully implemented of Company fileds new technologies of testing and production logging on such wells. Active development and massive implementation of permanent data gauges systems (PDG) let Company to use decline analysis methods of well performance. A lot of data obtained has led to new interpretation theories development, allowing to explain wells behavior and match pressure and rate data. For more robust estimation of parameters, production logging was performed with use of modern tool with arrays of sensors.

With the results obtained, series of one-layer model calculations was performed, resulting in optimal multi-frac design for one of the fields being studied.
Improved Approaches to Determination of the Current Oil Saturation of Reservoir Rocks According to Geophysical Data in the Fields of LUKOIL-PERM LLC
Authors: Gabnasyrov A.V. , Shilov A.V. , Ustinova Yu.V. , Nekrasov A.S.
Published: October 2015

Determination of the current oil saturation is one of the most urgent problems arised during monitoring of field development and well interventions planning on the fields being at the late development stage. At that, saturation nature in the casing is defined on the quality level with success rate of 50–60 % and it does not allow to predict water cut of the exposed interval since the determination error Fo ± 10 % may result in a water cut determination error of up to 90 %. Analysis of pulse neutron logging (PNL) results demonstrated that the main reason for low reliability of the studies is underestimation of rock and fluid lithological composition effect on the method indications.

To improve quality of developed formations saturation determination, PNL results (as the main method of determining the current oil saturation at LUKOIL-PERM LLC fields) and pilot work methods were analysed using WLS methods: ISGRL-Cl, SPNLGL-Cl, PPNGSL, С/O-logging, NEL for 2011–2014 period.

During the works, the most promising methods for current oil saturation determination – C/O logging and nanoelectronic logging were specified, which reliability was 80 % and 100 % respectively. At the same time, these methods were insufficiently tested for their mass usage.

To improve the PNL information content, an up-to-date interpretation approach is proposed, providing quantitative determination of oil saturation factor and prediction of the well water cut with accuracy of more than 80 % by taking into account the effect of lithological composition of the reservoir rocks and fluid properties on PNL indications.

The main advantage of the developed method is determination of current oil saturation factor and water cut prediction, and, therefore, a direct risk estimation during uncovering of any permeable interlayer. In addition, the approach implemented in the work, allows to check the formation recovery rate to provide monitoring of the well interventions development and performance according to the domestic geophysical methods.
East Siberian Field Waterflood Management
Authors: Burdakov D. A. , Rukavishnikov A. P. , Tuzovskiy M. A.
Published: October 2015

Waterflood strategy for balancing reservoir pressure and improving sweep is proposed. Work objective was to introduce new workflow that utilizes system approach in waterflood management for maximizing field performance.

The workflow included classic pattern analysis with rating of zones of interest based on complex parameters and diagnostic diagrams coupling recovery, pattern production, reservoir pressure and cumulative production before water breakthrough. Top rated patterns injection regimes are optimized with the aid of reservoir simulation. When choosing a well for conversion producing flow rates and chance of early water breakthrough or poor pressure response were considered. Detailed correlation, understanding of reservoir architecture, accurate mapping of properties and multiple simulation runs give the base for producer to injector conversion decisions.

Implementing of the waterflood management workflow resulted in watercut decrease in wells with early water breakthrough and promises higher recovery for new patterns since uniform injection replacement is controlled; Process of waterflood management turned into a routine process with known deliverables, action list is made and discussed every month; Zones with uneven sweep were identified and injection rates were optimized; Process of conversion candidate selection and making a conversion priority list was mastered; Injection wells with completion damage are spotted with the use of production analysis and added to stimulation program; Intervals of water breakthrough were determined based on correlation, petrophysics and production logging, squeeze jobs were planned;

Currently there are only few waterfloods online in East Siberia and sharing management experience and best practices can without a doubt add value to an existing work process or show the right route for the new one.
Iron Precipitation in Calcite, Dolomite and Sandstone Cores
Authors: Rady Ayten , Nasr-El-Din H.A.
Published: October 2015

Formation damage due to iron precipitation has been a major problem in the oil field. It has been established that as the pH of the injected acid increases, iron (III) ions start to precipitate and block the pores. However, where exactly this iron precipitates and how iron precipitation changes with different lithologies has not yet been studied.

Coreflood experiments were conducted to assess the effects of temperature and iron concentrations on the degree of damage caused by iron precipitation during an acid job. The temperature values tested were 200 and 300°F. Iron concentrations ranging from 5,000 to 10,000 ppm was used. The core effluent samples were analyzed by ICP to measure the concentrations of key cations.

After conducting core flood experiments, it was found that iron precipitation occurs across the entire core. Iron precipitation was severely detrimental in the sandstone cores compared to those of calcite and dolomite. While the limestone cores showed the least formation damage from iron precipitation, core flood tests indicated that as the iron concentration increases, the damage was more evident, especially in the sandstone cores. On the other hand, increasing the temperature adversely affected sandstone and dolomite cores but improved the final permeability of limestone cores.

In this study, the location of the iron precipitation is determined for three different lithologies. The effects of different parameters are studied to determine the best conditions that would lead to a decrease in iron precipitation and hence prevent formation damage. Iron control agents are not always needed, as previously thought.
WAG Optimization Algorithms Based on the Reaction of Producing Wells
Authors: Kazakov Kirill Viktirovich , Bravichev Kirill Arsenievich
Published: October 2015

Selection of optimal technological parameters of water-alternating-gas injection (WAG) in the oil reservoir is an important task. Technological parameters of WAG include volume ratio of injected water and injected gas, and total volume of water and gas (in reservoir conditions), injected in one cycle. The paper contains results of studing of efficiency of WAG with various technological parameters. Technological parameters of WAG had constant values and values varying in time depending on the reaction of producing wells for several algorithms.

Injected water and gas are distributed unevenly in the reservoir due to difference in their viscosities and also because of the heterogeneity of reservoir permeability. Distribution of saturations and relative permeabilities of fluids in the reservoir are being changed during WAG. It may require changes in the technological parameters of WAG during injection.

Compositional hydrodynamic simulation was used for the studies. The simulation took into account hysteresis of relative permeabilities and their change depending on the surface tension between oil and gas. The model for the simulation had the properties of the achimov deposits in Western Siberia. Fluidal model was adapted to a series of tests of samples of reservoir fluid. End points of relative permeabilities and the dependence of oil relative permeability in three-phase flowing was being selected during playback the results obtained with the replacement of oil by water, gas and WAG in core samples. Multivariate calculations were performed for uniform and nonuniform distribution of permeability (by area and by thickness) in the oil reservoir. It was considered waterflooding, gas injection, water alternating gas injection and simultaneous water-gas injection.

The simulation results showed that the oil recovery for a heterogeneous reservoir may differ significantly depending on technological parameters of WAG. The wrong choice of technological parameters of WAG can lead to substantial loss of oil recovery. It was developed algorithms for adjust technological parameters of WAG based on water-oil ratio and gas-oil ratio of producing wells of the impact area. Implementation of WAG by using these algorithms can achieve a maximum or close to a maximum oil recovery compared with water flooding, gas injection and WAG (simultaneous or separate injection of water and gas with constant in time of technological parameters). These algorithms can be used for implementation of WAG when distribution of permeability by area and by thickness is uncertain.
Determining Methods of Static Mechanical Properties of Poorly Consolidated Sand-rocks (by the Example of the Yuzhno-Russkoye Field)
Authors: Lushev Mikhail , Markin Maxim , Dubnitskiy Ivan , Vorobyev Vladislav
Published: October 2015

The article deals with the methodological approach to the research results correction of the rocks mechanical properties of the Turonian age based on the replacement of commonly used models of continuum mechanics for theoretical models of granulated solids mechanics. This method effectiveness is considered by the example of the Yuzhno-Russkoye field of the West Siberian Petroleum Province for producing interval T1-2dedicated to the Turonian Stage of Upper Cretaceous Series. Results correction of laboratory experiments of rocks strength properties is carried out that allows increasing the accuracy of their determination and improving the quality of geomechanical model of rocks that form the borehole for subsequent hydraulic fracturing design, and analyzing the bore hole stability correctly.