bluuebunny/crossref_metadata_2025_split huggingface dataset:
Semi-analytical Modeling of Multi-stage Fractured Horizontal Wells Coupled with Geomechanics: Considering Hydraulic Fracture Stress-sensitivity and Shale Anisotropy
Authors: Yao Shanshan , Wang Xiangzeng , Zeng Fanhua , Ju Ning 
Published: October 2016

Abstract
Production from multi-stage fractured horizontal wells (MFHWs) in shale reservoirs causes stress changes which further influence the conductivities of the hydraulic fractures. Moreover, many shale rocks are strongly anisotropic. The objective of this study is to develop a fast semi-analytical model for MFHWs with coupling geomechanics and fluid flow. The effects of stress-sensitive hydraulic fractures and shale anisotropy are considered.
This study first uses an exponential correlation between principal stresses and pore pressure changes in anisotropic shale. Then the correlation is applied to match experimental data of fracture conductivities vs. effective stress. The fracture compressibility in the exponential equation is stress-dependent rather than constant. Next, this study discretizes each hydraulic fracture into several slab source segments. For each segment in each time step, pressure distribution is calculated with source/sink functions. Then both stress field and hydraulic fracture conductivities are updated according to the pressure distribution with the aforementioned correlations before starting next time step.
Calculations of production rates with this model generate series of type curves for rate transient analysis of MFHWs with stress-sensitive hydraulic fractures. First of all, the production rate of a MFHW with stress-sensitive hydraulic fractures decreases faster than that with constant fracture conductivities at early-stage production. Secondly, the hydraulic fracture compressibility decreases with the increasing effective stress. Such change of the fracture conductivity is determined by the initial value and declining rates of fracture compressibility. Thirdly, shale anisotropy caused by kerogen leads to a larger increase of effective horizontal stresses when the reservoir pressure drops during production. Moreover, in terms of stress-sensitivity, fracture designs with improved conductivity are more resistant to the loss of fracture conductivity than large-volume designs for longer fracture length but lower conductivity.
A Composite Model for Multi-Stage Fractured Horizontal Wells in Heterogeneous Reservoirs
Authors: Yao Shanshan , Wang Xiangzeng , Zeng Fanhua , Li Min , Ju Ning 
Published: October 2016

Abstract
Analytical multi-linear models are popular in the well testing analysis of multi-stage fractured horizontal wells (MFHWs). But such models are challenged now. In high density network of hydraulic fractures, the fluid flow around fracture tips no longer behaves like linear flow. Moreover, the production behaviors of hydraulic fractures are different at different stages in heterogeneous reservoirs. To overcome the two challenges, this study develops a semi-analytical composite model for MFHWs in heterogeneous reservoirs.
The stimulated reservoir is regarded as a combination of several closed sub-systems with hydraulic fractures centered or uncentered. Each sub-system is further divided into several regions based on reservoir heterogeneity and flow characteristics. Reservoir and hydraulic fracture properties can be different in those regions. The production from each region is modeled by the solutions of linear flow equations or radial flow equations or source/sink functions. The production from a sub-system is modeled by coupling the solutions of regions in the sub-system. The production from the whole reservoir is then modeled by coupling the solutions of all sub-systems. The composite model was validated by analytical solutions in homogeneous reservoirs and numerical solutions in heterogeneous reservoirs. Calculations of production pressure and rates with this composite model generate type curves for the pressure and rate transient analysis of MFHWs. Two field cases are further analyzed with the type curves.
One novelty of this model is to consider the non-linear flow around hydraulic fracture tips. Therefore, our model is better prepared for incorporating pressure-dependent heterogeneous reservoir properties in the future. The other novelty of this study is the ability to model the different production behavior at different fracture stages in complex heterogeneous reservoirs.
Fracturing in Challenging Low-Temperature Reservoirs: Combining Laboratory and Field Approach Produces Promising Results
Authors: Parkhonyuk Sergey , Klyubin Artem , Vernigora Denis , Olennikova Olesya , Lisitsyn Andrey , Konchenko Andrey , Sitdikov Dmitry , Bildanov Vladislav , Gaponov Mikhail 
Published: October 2016

Abstract
Development of traditional oil reservoirs is becoming increasingly challenging with time as more reservoirs move to brown state. The Bashkiria field complex is typical example of such reservoir: development started in 1932 and as of today, more than 80% of initial oil reserves have been produced. Thus, the only method to make wells produce economically is hydraulic fracturing.
Particularities of the region are viscous crude oils, small net height of the reservoir, and low bottomhole static temperatures coupled with depleted reservoir pressure. This imposes additional constraints on the hydraulic fracturing design. The typical practice in region is to employ an aggressive pumping strategy to maximize fracture conductivity and minimize the amount of fluid pumped into the reservoir. Robust fluid is required to avoid premature screenout due to proppant settling.
Another essential component of the fracture conductivity is fracturing fluid breakers. The goal in using breakers is to reduce fluid viscosity and break polymer residues in the proppant pack after treatment to facilitate fracture cleanup.
Traditionally, breakers based on ammonium persulfate (APS) (both live and encapsulated) are used in Russian oil fields. They have proved successful in the typical conditions of Western Siberia (80 to 120°C). Enzyme-based breakers have limitations on temperature range and fluid viscosity range.
In this paper, we focus on development of novel fracturing fluid tailored for Bashkiria oilfield conditions. An enzyme breaker was compared with traditional oxidative breakers.
Production analyses were performed using actual treatment data and post-fracturing production data and comparing them with conventional treatment results.
Laboratory testing proved that in terms of fracture-pack conductivity, the new enzyme breaker produced approximately twice the conductivity, as did oxidative breakers over the temperature range of the Bashkiria region. Implementation of novel fluid with pressure-independent viscosity behavior led to a reduction of more than twice the screenout rate with zero fluid-related screen outs. Up to 9 times production increase resulted based on a dimensionless productivity index.
Assessing Existing Effluent Analysis Requirements to Improve Effluent Quality Reporting
Authors: Arhin-Andoh C.. 
Published: October 2016

Abstract
Ghanaians have been concerned about the pollution of the surrounding waters of the country since the start of offshore exploration activities (GNA, 2013). Fishermen have complained about the effects on availability of fish, while coastal dwellers have attributed every strange discoloration of the coastline to activities of oil companies. There has also been dissatisfaction expressed in the inefficiencies of the Jubilee environmental impact assessment conducted before the start of operations. This project served to ascertain if indeed oil companies in Ghana were complying with meeting international and EPA Ghana requirements for management of produced water disposal identified any gaps and came out with a unique guideline for Ghana to implement.
According to R.L Petrusac et al(2000), produced water is one of the largest streams of waste from offshore facilities. In order to identify gaps in existing effluent analysis requirements, this paper assessed produced water, from FPSO Kwame Nkrumah, a base case scenario of current analysis requirements in Ghana was assessed, selected countries; US, UK, Norway and Nigeria analysis requirements were also examined to bring out the gaps and a guideline was drafted for use by stakeholders.
Taking a look at analysis required in the various countries compared with Ghana, it was seen that the requirements varied from one country to the other. The only requirement running through all was the oil and grease requirement. This was accepted by all as being an important value to be monitored. A guideline was developed to include all other analysis in the other countries which were not currently being monitored in Ghana. This guideline will be useful to stakeholders interested in finding out produced water effluent composition in order to prevent pollution and also advise on important analysis required to be carried out.
Preventing Injury and Fatalities - Applying a Preventing Serious Injury and Fatalities Field Guide
Authors: Ndahondyapo Pitra Deodete N , Lima Jorge 
Published: October 2016

Abstract
The oil industry has been successful in reducing injuries along the past couple of years without improving fatality rates and Serious Injuries data. The industry needs to execute high risk work with consistency and in order to prevent serious injuries and fatalities.
This article presents how Health, Environment and Safety (HES)-Workforce Safety team effectively increase focus on activities more likely to cause serious injuries and fatalities, by applying a new way of thinking about the traditional ‘Safety Pyramid’ and presenting results of the practical implementation of a Fatality Prevention field guide.
The fatality prevention approach recommends a methodology that focus on five steps to improving fatality prevention efforts and outcomes which are: understand highest risk activities and incident types, validate field-level performance associated with these activities,, assign accountability for actions, align protective and other systems,, and align behaviors associated with high risk activities and incident types.
The Preventing Serious Injuries and Fatalities field guide is a tool used to raise Preventing Serious Injury and Fatalities awareness among workers, supervisors, and work leaders, and supplements ongoing efforts to prevent Serious Injuries and Fatality without replacing existing permitting procedures and safe work practices. The field guide helps review high risk potential hazards and mitigations associated with all phases of high risk work, including, planning, permitting, implementing and closeout. This paper present result of practical implementation of the Fatality Prevention field guide in operations.
Dope-Free Technology in Oilfield Tubulars Reduces Environmental Discharge Amongst Other Benefits
Authors: Bruce-Cathline Cyril , Goretta Emiliano Actis , Franceschi Esteban De 
Published: October 2016

Abstract
Environmental impact reduction is an essential component that compliments the commitment of every Oil and Gas Operator, Service provider, etc. towards the promotion of a greener environment. From the planning phase of oilfield operations, OCTG- Oil-Country Tubular Goods require the use of thread compounds (pipe dope) to protect machined surfaces from environmental corrosion, to lubricate the connections during installations and also provide sealability among other expectations.
From the production, storage, preparation for operations, running and installation of OCTG, the use of thread compounds cannot be overlooked. These compounds like most Oilfield chemicals expose both personnel and environment to a harmful condition, placing all personnel involved in this value chain of material and service delivery affected one way or the other. A technologically crafted modern solution/alternative was developed in 2003 to fully eliminate the use of these thread compounds- A Dope-Free Solution replacing both storage and running compounds (Carcagno, G., Castiñeiras, T., & Dag, J., 2007). These Dope-Free connections are equipped with a dry coating applied through a controlled industrial process.
It was first developed to meet the strict environmental requirements in the North Sea. In line with the "zero discharge" policy, this dry coating applied onto threads soon demonstrated other operative , health and safety advantages as compared to the traditional thread compounds. A presentation is made highlighting the benefits with the use of the Dope-Free technology, with a focus on health, safety and environment impact during storage, cleaning, inspection, running and post running operations including waste management. Two areas where tubular are used are considered; Rig site and Service yards. For example, the elimination of human application of thread compounds, the elimination of the need to clean thread protectors which could amount to other operative costs.
In this study, a side by side comparison is done to realize the benefits.
El programa “Pueblos Mágicos” y la sustentabilidad turística; el caso de Cosalá y los eventos “Cosaltazo” y “Cosalazo”
Authors: Ibarra Michel Juan Pedro , Velarde Valdés Mónica 
Published: October 2016

El presente estudio se enfoca en el análisis de dos eventos el “Cosaltazo” y “Cosalazo”<strong> </strong>que se desarrollan en la comunidad de Cosalá, Sinaloa que forma parte del programa “Pueblos Mágicos” y que constituye un ejemplo de cómo se puede desviar la orientación sustentable que exigen los lineamientos de dicho programa, que promueve una actividad turística sustentable como eje principal del desarrollo económico de las comunidades elegidas. A partir de la implementación del programa en la comunidad se han implementado estrategias que han permitido la conservación y restauración del patrimonio cultural y arquitectónico del lugar, pero con la autorización de los eventos que hoy se estudian se constata el riesgo que pueden constituir productos turísticos que no se caracterizan por seguir los lineamientos de sustentabilidad que se exigen en las reglas de operación del programa señalado. Esta investigación analiza la forma en que se ha implementado dicho programa en la comunidad y las opiniones de pobladores, comerciantes y prestadores de servicios que ponen en evidencia los efectos negativos que tienen la celebración de dichos eventos para la conservación del patrimonio arquitectónico y las tradiciones del lugar así como la necesidad de una mayor y mejor coordinación entre los tomadores de decisiones que orienten de forma adecuada la actividad turística desde la creación de productos turísticos sustentables.
MINI REVIEW ON THERAPEUTIC PROFILE OF PHENOXY ACIDS AND THIER DERIVATIVES
Authors: Begum Shaheen , K. Bharathi , S.r.g Prasad K.v. 
Published: October 2016

<p>Phenoxy acids and their derivatives are associated with a variety of biological activities such as antihyperlipidemic, hypoglycemic, antimicrobial, antiviral, antitubercular, anti-inflammatory, analgesic, antioxidant, anticancer and antihypertensive activities. This mini review outlines diverse biological properties of phenoxy acids and their derivatives. </p>
MAGNETICALLY SELF-REGULATED FORMATION OF EARLY PROTOPLANETARY DISKS
Authors: Hennebelle Patrick , Commerçon Benoît , Chabrier Gilles , Marchand Pierre 
Published: October 2016

ABSTRACT
The formation of protoplanetary disks during the collapse of molecular dense cores is significantly influenced by angular momentum transport, notably by the magnetic torque. In turn, the evolution of the magnetic field is determined by dynamical processes and non-ideal MHD effects such as ambipolar diffusion. Considering simple relations between various timescales characteristic of the magnetized collapse, we derive an expression for the early disk radius,

where M is the total disk plus protostar mass,

is the ambipolar diffusion coefficient, and B

z
is the magnetic field in the inner part of the core. This is significantly smaller than the disks that would form if angular momentum was conserved. The analytical predictions are confronted against a large sample of 3D, non-ideal MHD collapse calculations covering variations of a factor 100 in core mass, a factor 10 in the level of turbulence, a factor 5 in rotation, and magnetic mass-to-flux over critical mass-to-flux ratios 2 and 5. The disk radius estimates are found to agree with the numerical simulations within less than a factor 2. A striking prediction of our analysis is the weak dependence of circumstellar disk radii upon the various relevant quantities, suggesting weak variations among class-0 disk sizes. In some cases, we note the onset of large spiral arms beyond this radius.
Les situations de crise à l’hôpital : défis ou opportunités d’émergence de l’apprenance ?
Authors: Duarte Anne-Paule 
Published: October 2016

Cette étude qualitative a pour objectif d’explorer les opportunités d’apprenance inhérentes aux situations de crise à l’hôpital. L’enquête de terrain a été menée sous forme d’entretiens auprès de 31 professionnels de santé de divers établissements hospitaliers. Une cartographie des situations de crise recensées aux niveaux macro et micro de l’organisation a été élaborée à partir des récits. L’apprenance se manifeste sous forme d’apprentissages informels et met en évidence une organisation apprenante. Les professionnels de santé révèlent de véritables compétences intrapersonnelles et interpersonnelles. Une démarche autoréflexive avec un sentiment d’efficacité personnelle et une mutualisation des diverses trajectoires de vie, de formation et professionnelle émerge.
“Ink-Play”: Walter Benjamin’s Chinese Curios
Authors: Gilloch Graeme , Kang Jaeho 
Published: October 2016

Dans cet article, nous explorons deux aspects interconnectés de la pensée de Walter Benjamin qui ont reçu une attention limitée : la figure du peintre chinois comme un exemple d’art traditionnel et la réflexion de Benjamin sur les tableaux chinois que l’on retrouve dans une chronique artistique à propos d’une exposition tenue à Paris en 1937. Lire de façon combinée ces réflexions sur les artistes chinois et l’art offre un point de vue particulier et intéressant sur des concepts familiers de la théorie benjaminienne comme l’image de pensée ( Denkbild ) et l’image dialectique. En effet, nous soutenons que la notion de ink-play peut contribuer à notre compréhension du concept de modernité.
Involvement, Collaboration and Engagement – Social Networks through a Pedagogical Lens
Authors: Seifert Tami 
Published: October 2016

<p class="JLDAbstract" align="left">Social networks facilitate activities that promote involvement, collaboration and engagement. Modelling of best practices using social networks enhances its usage by participants, increases participants confidence as to its implementation and creates a paradigm shift to a more personalized, participatory and collaborative learning and a more positive attitude towards its implementation. The contribution of the study described in this paper resides in the enhancement of teaching and learning methods that make use of the social network environment and shifts the focus of learning from the teacher to the learner. This breaks down the boundaries of time and place for teaching and learning. Another contribution is the strengthening of teachers’ personal and professional capabilities and the promotion of teaching-learning processes transpiring beyond the classroom boundaries by sharing contents, current communication, active learning and collaborative work. </p>
Vivencias de las jóvenes diagnosticadas de escoliosis idiopática
Authors: Bonilla Carrasco Maria Isabel , Solano Ruiz Maria Carmen 
Published: October 2016

Justificación: Durante la adolescencia y la juventud acontecen cambios psicológicos y fisiológicos que forman parte del desarrollo normal de la persona. La irrupción de la escoliosis en esta edad influye en la vivencia de la autopercepción corporal. <br /><br />Objetivo: Conocer cómo una deformidad corporal influye en la estabilidad emocional de las jóvenes diagnosticadas de escoliosis. <br /><br />Diseño: Metodología cualitativa fenomenológicas situada en la hermenéutica.<br /><br />Método: Se utilizó una entrevista semiestructurada y dirigida a mujeres jóvenes con escoliosis idiopática ingresadas en la unidad de raquis del Hospital Vall d´Hebron en Barcelona.<br /><br />Resultados: Los principales resultados señalan un compromiso emocional que afecta a las actividades de la vida diaria de las jóvenes, manifestándose, en algunas ocasiones, con sentimientos de vergüenza, tristeza, preocupación, miedo, amargura, complejo y rabia. La experiencia se vive como un duelo ante la pérdida de expectativas futuras.<br /><br />Conclusiones: Los sentimientos y las emociones vividas y referidas por estas pacientes comprometen su estabilidad emocional. <br /><br />
Preferential 5‐Methylcytosine Oxidation in the Linker Region of Reconstituted Positioned Nucleosomes by Tet1 Protein
Authors: Kizaki Seiichiro , Zou Tingting , Li Yue , Han Yong‐Woon , Suzuki Yuki , Harada Yoshie , Sugiyama Hiroshi 
Published: October 2016

AbstractTet (ten–eleven translocation) family proteins oxidize 5‐methylcytosine (mC) to 5‐hydroxymethylcytosine (hmC), 5‐formylcytosine (fC), and 5‐carboxycytosine (caC), and are suggested to be involved in the active DNA demethylation pathway. In this study, we reconstituted positioned mononucleosomes using CpG‐methylated 382 bp DNA containing the Widom 601 sequence and recombinant histone octamer, and subjected the nucleosome to treatment with Tet1 protein. The sites of oxidized methylcytosine were identified by bisulfite sequencing. We found that, for the oxidation reaction, Tet1 protein prefers mCs located in the linker region of the nucleosome compared with those located in the core region.
Development of Tetrachlorophthalimides as Liver X Receptor β (LXRβ)‐Selective Agonists
Authors: Nomura Sayaka , Endo‐Umeda Kaori , Makishima Makoto , Hashimoto Yuichi , Ishikawa Minoru 
Published: October 2016

AbstractLiver X receptor (LXR) agonists are candidates for the treatment of atherosclerosis via induction of ABCA1 (ATP‐binding cassette A1) gene expression, which contributes to reverse cholesterol transport (RCT) and to cholesterol efflux from the liver and intestine. However, LXR agonists also induce genes involved in lipogenesis, such as SREBP‐1c (sterol regulatory binding element protein 1c) and FAS (fatty acid synthase), thereby causing an undesirable increase in plasma and hepatic triglyceride (TG) levels. Recent studies indicate that LXRα contributes to lipogenesis in liver, and selective LXRβ activation improves RCT in mice. Therefore, LXRβ‐selective agonists are promising candidates to improve atherosclerosis without increasing plasma or hepatic TG levels. However, the ligand‐binding domains in the two LXR isoforms α/β share high sequence identity, and few LXR ligands show subtype selectivity. In this study we identified a tetrachlorophthalimide analogue as an LXRβ‐selective agonist. Structural development led to (E)‐4,5,6,7‐tetrachloro‐2‐(2‐styrylphenyl)isoindoline‐1,3‐dione (24 a), which shows potent and selective LXRβ agonistic activity in reporter gene assays. In binding assays, compound 24 a bound to LXRβ preferentially over LXRα. It also induced the expression of ABCA1 mRNA but not SREBP‐1c mRNA in cells. Compound 24 a appears to be a promising lead compound for therapeutic agents to treat atherosclerosis without the side effects induced by LXRα/β dual agonists.