bluuebunny/crossref_metadata_2025 huggingface dataset:
A INFLUÊNCIA DOS MATERIAIS DAS MARGENS E DA VEGETAÇÃO CILIAR NA EROSÃO DE MEANDROS: O CASO DO RIO CLARO, AFLUENTE DO RIO ARAGUAIA
Authors: Castro Wallas de Souza , De-Campos Alfredo Borges , Zancopé Márcio Henrique Campos
Published: September 2019

A erosão sobre as margens côncavas é um processo intrínseco à migração lateral de meandros. A hidráulica da corrente fluvial e os materiais constituintes das margens influenciam as taxas de erosão e migração lateral. O objetivo deste artigo é verificar a correlação entre as taxas de erosão marginal de dois meandros do baixo curso do Rio Claro, afluente do Rio Araguaia, Centro-Oeste do Brasil, e a natureza dos materiais constituintes das margens côncavas (variação faciológica e desagregação espontânea – estabilidade geotécnica) e a vegetação ciliar presente e ausente. As taxas de erosão foram determinadas pelo monitoramento (2013-2014) de pinos de erosão instalados ao longo das margens côncavas, enquanto que os materiais constituintes foram caracterizados pela descrição faciológica das margens e análises laboratoriais para determinação granulométrica e desagregação espontânea de amostras em submersão aquosa. Os resultados mostraram elevadas taxas de erosão das margens côncavas dos meandros (entre 67 cm e 120 cm), concentradas próximas ao eixo dos meandros, bem como nas porções das margens constituídas por areia média e grossa e resposta mais rápida a desagregação sob submersão. As margens com vegetação ciliar presente não apresentaram taxas de erosão menor que as margens desmatadas, sugerindo que a vegetação ciliar contribui pouco para frear a erosão marginal e migração lateral de sistemas fluviais meandrantes similares ao Rio Claro.
Ultrasonic Predictors of Dry Eye Syndrome in Sarcoidosis
Authors: Safonova T. N. , Kharlap S. I. , Eksarenko O. V.
Published: September 2019

Objective. To identify clinical and morphofunctional changes in the lacrimal gland in sarcoidosis.

Material and methods. Ultrasonography was conducted in 53 patients (106 eyes) with a verified diagnosis of systemic sarcoidosis (7 men and 46 women) whose age was 31 to 72 years.

Results. Different types of lacrimal gland structural changes in sarcoidosis were detected. Comparing the acoustic and functional findings revealed a high correlation (r > 0.7) between these parameters as vascularization index, a reflex component of tear secretion, and the presence of tubular structures. Types of changes in the acoustic structure of the lacrimal glands were identified, which were designated as edematous and polymorphic changes, as well as atrophic changes with a necrotic component.

Conclusion. The findings can be used to diagnose lacrimal gland changes in patients suffering from sarcoidosis.
Possibilities of Computed Tomography Urography and Magnetic Resonance Urography as Up-To-Date and Informative Techniques in the Diagnosis of Traumatic Ureteral Strictures
Authors: Davydova E. S. , Egorova E. A.
Published: September 2019

Objective. To assess the sensitivity of computed tomography urography (CTU) and magnetic resonance urography (MRU) (native versus contrast-enhanced studies) in patients with traumatic ureteral strictures.

Material and methods. The data of 51 CTUs and 34 MRUs made in patients with upper urinary tract injuries were prospectively analyzed. The studies were performed using an Aquilion Prime 160-slice scanner (Toshiba, Japan) and high-field devices at a magnetic field strength of 1.5 Tesla Vantage Atlas (Toshiba, Japan) and at 3.0 Tesla Ingenia (Philips, Netherlands). Excretory urography was also carried out in 92.2% of cases; ultrasound examination was made in 74.5%. The degree of obstruction, its causes, the state of the adjacent structures, and the presence of complications were assessed.

Results. All (100%) CTU studies correctly estimated the level of stricture of the ureter; the lower third of the organ was involved most frequently (68.6%). MRU identified traumatic strictures in 94.0% of cases. MRU and CTU could be confined to native series in 51.0 and 27.5% of patients, respectively. MRU more commonly revealed the changes concurrent with injuries: there was diffuse ureter wall thickening in 44.1% (27.5% at for CTU), periureteral fat infiltration in 43.1% (37.2% at CTU), and pelvic fluid accumulation in 9.8% (7.8% at with CTU). The techniques could also establish the presence of sinus tracts: MRU was useful in the preoperative imaging of pathological fistulas in 100%. CTU was able to demonstrate the leakage of a contrast agent and/or its flow into the vagina in 66.7%.

Conclusion. MRU demonstrates the sensitivity comparable to that of CTU in detecting ureteral injuries (including in diagnosing complications, such as fistulas) and can be used in patients with contraindications to CTU and, due to the absence of ionizing radiation, for follow-up studies.
The Possibilities of Bronchoscopy and Endosonography in the Differential Diagnosis of Mediastinal Tuberculous and Metastatic Lesions
Authors: Sivokozov I. V. , Evgushchenko G. V. , Berezovskiy Yu. S. , Sazonov D. V. , Karpina N. L.
Published: September 2019

This clinical case shows the experience in concurrently using video-assisted bronchoscopy and endosonography in a patient with mediastinal adenopathy for differential diagnosis between tuberculous and metastatic changes. It demonstrates the possibilities and limitations of using both classical bronchoscopy and transesophageal endosonography with a EUS-b-FNA using echobronchoscope.
Pemanfaatan vitamin C dalam perekayasaan pakan untuk meningkatkan pertumbuhan dan kelulushidupan benih ikan kerapu macan (Epinephelus fuscoguttatus).
Authors: Mudiarti Luky , Kursistiyanto Nurcahyo
Published: September 2019

Upaya pengkajian pakan ikan kerapu terus dikembangkan. Ikan ini membutuhkan pakan dengan protein yang tinggi sehingga berdampak pada tingginya  biaya pakan dan buangan limbah bernitrogen pada lingkungan hidupnya. Salah satu upaya untuk mengurangi kebutuhan protein tersebut adalah dengan menambah kebutuhan lemaknya. Ikan akan memanfatkan lemak sebagai sumber energi. Penambahan vitamin C secara tidak langsung berperan dalam mekanisme transport asam amino dan asam lemak agar lebih efisien sehingga diharapkan dapat meningkatkan dan menghasilkan pertumbuhan dan kelulushidupan kerapu macan. Bahan yang  digunakan adalah benih kerapu macan  berumur 45 hari dengan berat awal 0,77 ± 0,07 gram. Penelitian eksperimental laboratorium ini menggunakan Rancangan Acak Lengkap dengan 4 ulangan pada tiap-tiap perlakuan. Perlakuan yang digunakan (A) uji pakan dengan penambahan vitamin C seberat 0 mg, (B): 75 mg (C) 150 mg dan (D): 225 mg/ kg pakan. Pemberian pakan dilakukan secara at satiation. Pakan yang  diberikan berupa pelet kering dengan kandungan protein 40% dan lemak 20%. Variabel penelitian yang digunakan yaitu  pertumbuhan, Laju pertumbuhan Spesifik, Rasio konversi pakan, Protein efisiensi ratio serta kelulushidupan ikan Data dianalisis dengan analisis varians dan polinomial ortogonal untuk mengetahui dosis optimal vitamin C dalam pakan. Untuk mengetahui perbedaan perlakuan diuji menggunakan uji F dengan program SPSS versi 17. Hasil penelitian menunjukkan bahwa tren pertumbuhan ikan kerapu yang diberi pakan buatan tersuplemen vitamin C memiliki efek signifikan p <0,01) pada semua variabel. Perlakuan terbaik diperoleh pada perlakuan C 150 mg/kg.
Medicaid Utilization Before and After a Natural Disaster in the 2016 Baton Rouge–Area Flood
Authors: Phillippi Stephen W. , Beiter Kaylin , Thomas Casey L. , Sugarman Olivia K. , Wennerstrom Ashley , Wells Kenneth B. , Trapido Edward
Published: September 2019

Objectives. To understand changes in behavioral health services utilization and expenditures before and after natural disaster with an adult Medicaid population affected by the Baton Rouge, Louisiana–area flood (August 2016).

Methods. We examined de-identified behavioral health claims data for Medicaid-insured adults in the affected region for 10 months before and after flooding (October 2015–June 2017). This constituted 273 233 provider claims for 22 196 individuals. Claims data included patient gender, behavioral health diagnoses, treatment dates, and costs. We made adjustments for Medicaid expansion by using monthly enrollment data.

Results. Overall, most male patient behavioral health care visits were for substance use disorders (33.6%) and most female patient behavioral health care visits were for depression-related disorders (30%). Both diagnostic categories increased after the flood by 66% and 44%, respectively. Expansion accounted for a 4% increase in claims. Postflood claims reflected 8% to 10% higher costs.

Conclusions. Greater amounts of behavioral health care services were sought in all 10 months of the postflood study period. We observed gender differences in use of services and diagnoses. Behavioral health care services following natural disasters must be extended longer than traditionally expected, with consideration for specific population needs.
Variación temporal de la morfología funcional del fitoplancton en una planicie inundable del Caribe Colombiano
Authors: Zabala Agudelo Ana María , Hernández Esnedy , Agudelo Diana María , Aguirre Nestor Jaime , Vélez Fabio De Jesús
Published: September 2019

Analizamos la variación temporal de los grupos funcionales basados en la morfología del fitoplancton (GFBM) en el sistema inundable de Ayapel a través de la comparación de dos muestreos previos realizados entre los 2005 y  2007 y uno nuevo hecho en el 2015. Se estimó el biovolumen (mm3.l-1) y los rasgos morfológicos como volumen, relación superficie/volumen (S/V) y dimensión linear máxima (DLM). El análisis temporal fue realizado acorde con los niveles de precipitación pluvial, y mediante un análisis de agrupamiento se definieron dos períodos previos (época seca y época de transición) y uno nuevo correspondiente al año 2015 (msENSO: época seca con influencia ENSO). En las épocas seca y de transición, el grupo predominante fue el GFBM III con altas DLM (108.77 µm) y relaciones S/V (1.44 µm), mientras que en el msENSO se observaron bajos biovolumenes (0.016 mm3.l-1) y la predominancia del GFBM V. La comparación de la morfología funcional entre los años evidenció la transición de formas filamentosas a formas flageladas del fitoplancton, permitiéndole un mejor ajuste ante las presiones ambientales del área de estudio.
Dípteros acuáticos del departamento del Chocó, Colombia
Authors: Murillo Zuleyma Mosquera , Sánchez Vazquez Sandra Patricia
Published: September 2019

Se presenta un reporte preliminar sobre la riqueza y distribución de los dípteros acuáticos en el departamento del Chocó, a partir de 490 especímenes (larvas y pupas) de la Colección Limnológica del Chocó (CLCH-Insec, Universidad Tecnológica del Chocó), que corresponden a 18 municipios (entre 5 y 3202 m s.n.m.), 46 corrientes hídricas de diferente orden y 14 ecosistemas lénticos de las cuencas de los ríos Atrato, San Juan y Baudó. Se reportan 12 familias y 30 géneros, de los cuales 4 familias y 16 géneros, son registrados por primera vez para el Chocó. Chironomidae es la familia más abundante y más ampliamente distribuida, mientras que Dixidae y Sciomyzidae son las familias de menor abundancia y distribución. La mayor riqueza taxonómica la registran las familias Culicidae y Ceratopogonidae, con cinco géneros cada una. Las macrófitas son el sustrato con mayor riqueza específica. El mayor registro taxonómico se encuentra en la cuenca del río Atrato, con 11 familias y 24 géneros. Estos resultados permiten evidenciar la enorme diversidad de los dípteros acuáticos en el departamento del Chocó y la necesidad de adelantar nuevas investigaciones que amplíen su conocimiento taxonómico y ecológico en la región.
Hábitos alimenticios del sable Trichiurus lepturus en el Golfo de Urabá, Caribe colombiano
Authors: Arenas-Uribe Sara , Leal-Flórez Jenny , Sandoval Alejandro , Perez Villa Andres Felipe , Hernandez-Morales Andres Felipe
Published: September 2019

Se estudiaron los hábitos alimenticios del pez comercial Trichiurus lepturus, un mesodepredador con un papel importante en el flujo de energía en las redes tróficas costeras, con el objeto de contribuir al conocimiento de su ecología, herramienta para su conservación e insumo para el ordenamiento pesquero del Golfo de Urabá, en el noroeste de Colombia. Usando redes de enmalle se capturaron 320 individuos, de los que se obtuvieron 208 estómagos con contenido. El espectro alimenticio de la especie está integrado por 26 ítems, pertenecientes a tres grandes grupos taxonómicos: peces, crustáceos y moluscos. Entre estos, los engráulidos (Engraulidae) son el principal componente en todos los sitios de muestreo, sobresaliendo Centengraulis edentulus y varias especies del género Anchoa. Se encontró un traslape de presas entre los sitios, siendo evidente la importancia de las áreas de manglar para alimentación. Sin embargo, no hubo variación estacional ni diferencias entre sexos en la composición de la dieta, dado que los engráulidos, su principal presa, son uno de los recursos pesqueros más abundantes en el Caribe colombiano.
Modelo metodológico para el fortalecimiento de capacidades dinámicas de innovación en mipymes
Authors: Morales-Rubiano María Eugenia , Duque-Orozco Yenni Viviana , Ortiz-Riaga Carolina
Published: September 2019

Rev.esc.adm.neg

Este artículo tiene como objetivo presentar un modelo de intervención para el fortalecimiento de las capacidades de innovación en micro, pequeñas y medianas empresas, a través de una aproximación cualitativa en la que se tuvieron como referentes tres capacidades dinámicas para la innovación: la exploración, la explotación y el mantenimiento o reconfiguración, tomando como eje fundamental la estrategia pedagógica del «taller». Las mipymes seleccionadas para la intervención pertenecen a los sectores turismo y confecciones, en las ciudades de Bogotá y Pereira. 

El documento en su primera parte presenta los referentes teóricos acerca de capacidades dinámicas para la innovación; en la segunda sección expone la metodología empleada para el diseño propuesto; en la tercera plantea el diseño metodológico para el fortalecimiento de capacidades para la innovación en mipymes y concluyendo el texto se encuentra una descripción y explicación de los resultados alcanzados, acompañado con algunas reflexiones puntuales al respecto.

Los resultados muestran que la diversidad de capacidades presentes en las mipymes hace necesario encontrar una variable que permita agruparlas para realizar la intervención y, de esta manera, complementar la estrategia de sesiones grupales con visitas personalizadas y de seguimiento, para garantizar el apoyo a quienes presentan mayores dificultades en el proceso de apropiación de los conceptos y procesos propuestos.
Diagnóstico del capital intelectual en una empresa maquiladora textil mexicana
Authors: Bermúdez-Rodríguez Sahara , Hernández-Ibarra Alfredo
Published: September 2019

Rev.esc.adm.neg

Con el fin de establecer el valor que una empresa tiene en relación a sus activos intangibles, mediante un diagnóstico del capital intelectual, se formuló como objetivo de la investigación que da origen a este artículo, valuar el capital intelectual (CI) en una empresa maquiladora textil mexicana, a través de la identificación de saberes, capacidades, experiencias y habilidades de las personas que la conforman.

Se consideró necesario llevar a cabo la identificación de cada uno de los elementos que conforman el capital intelectual —humano, estructural y relacional— con la intención de tener un acercamiento respecto a sus fortalezas y oportunidades. La metodología utilizada fue de tipo descriptiva, con el propósito de determinar los componentes relevantes del capital intelectual.

Para ello, se obtuvieron datos de la totalidad de la planta de personal de la empresa -57 empleados- a través de los instrumentos de cuestionario y encuestas y con base en los resultados observados se valuaron en una escala de 1 a 5 — siendo 5 el puntaje mayor— cada una de las dimensiones del capital intelectual, siendo estos los resultados: capital relacional 4.27; capital estructural 3.80 y capital humano 3.69. A partir de ello se identificó que la empresa tiene áreas de oportunidad que, de atenderse, permitirán alcanzar los objetivos institucionales trazados.
Formación del perfil emprendedor en educación superior en la Universidad de Sonora, México
Authors: Leyva-Carreras Alma Brenda , Alcántara-Castelo Jesús Rodolfo , Espejel-Blanco Joel Enrique , Coronado-García Manuel Arturo
Published: September 2019

Rev.esc.adm.neg

En este documento se presenta el marco conceptual y la metodología que se siguió para realizar la investigación; además se indica cuál ha sido el proceso de análisis de los datos y los resultados, las conclusiones y algunas recomendaciones e implicaciones sociales.

Se aplicó una metodología mixta, donde la primera fase consistió en un análisis exploratorio mediante prueba piloto, con el fin de contextualizar el problema objeto de análisis, así como la validación del instrumento de medición; y en la segunda fase, con la recolección de datos a través de una encuesta de cuestionario semi-estructurado a alumnos de la Licenciatura en Administración de la Universidad de Sonora, unidad Hermosillo, Sonora, México, se llevó a cabo un análisis estadístico con modelos de ecuaciones estructurales PLS-SEM. 

Los principales resultados muestran que los alumnos con habilidades emprendedoras están conscientes de la importancia que tienen las habilidades personales, lo que les permite desarrollar de forma efectiva las sociales, y opinan que durante su formación profesional podrán aprender y mejorar las intelectuales, que son necesaria en las habilidades de logro al emprender nuevos negocios.
Importancia de los enfoques cooperativos en el desarrollo empresarial de algunas compañías hispanoamericanas exitosas
Authors: Mera-Bastidas María Cecilia , Terán-López Ángela Tatiana , Barrera-Ojeda Diego Mauricio , Gomajoa Hugo Andrés , Rojas-Navarro José Faruk
Published: September 2019

Rev.esc.adm.neg

Este artículo tiene por objeto principal realizar una revisión del enfoque cooperativista que han tomado algunas compañías hispanoamericanas exitosas, aspecto que les ha permitido aumentar su competitividad, posicionarse en los mercados y que podría constituirse en modelo potencial para muchas mipymes, permitiendo el mejoramiento de la calidad de vida de las personas que de estas actividades dependen. Para tal efecto, se presenta un marco teórico enfocado en la economía solidaria y sus características, seguido de la descripción de experiencias exitosas en conglomerados agroindustriales latinoamericanos y de buenas prácticas desde el punto de vista logístico, que podrían potencializar a las asociaciones, dadas las principales vocaciones productivas de sus regiones. 

La consolidación documental de las experiencias de éxito empresarial bajo el modelo clúster agroindustriales y economía solidaria en Latinoamérica, permitió evidenciar que existen regionalmente diversas iniciativas económico - empresariales de asociatividad y cooperativismo que han logrado posicionarse y ser reconocidas con mucho mayor éxito, que empresas con enfoques no cooperativos, siendo el sector productivo, específicamente agroindustria, donde hay mayor concentración de empresas bajo el régimen solidario, seguido del sector servicios. Las empresas solidarias, llámense asociaciones o cooperativas deben su éxito principalmente a la generación por parte de los gobiernos, de políticas públicas que promueven su creación y sostenibilidad.
Unlocking Development by Solving a Contacts Interpretation Mystery
Authors: Hadidi Shahab , Boya Ferrero Maria
Published: September 2019

The identification of the fluid fill history is a necessity for the development strategy of any field, in particular in the Middle East where tectonic history is often reported to affect fluid distribution and contacts in many fields. The fluid fill concept for a low permeability carbonate field has been re-evaluated and modified from a tilted contact interpretation with imbibition of the deepest unit to a field-wide flat contact and primary drainage saturation distribution. The oil volumes in the reservoir under study are sensitive to minor changes in the structure and fluid fill due to the relatively low structural dip and low permeability transitional nature of the reservoir. The paper highlights the importance of removing preconceptions in data analysis and ensuring consistency on interpretations between different available data sources. It also demonstrates how data quality could completely change the fluid fill concept.

The three main reservoir units of the Lower Shuaiba A, Lower Shuaiba B and Kharaib have been charged from two oil migration events. Structural changes post the first primary drainage are revealed by regional seismic images of the shallower horizons. Due to the rock low permeability, the water saturations are above irreducible value and the whole interval is in the "transition zone". Kharaib unit was believed to be imbibed by the aquifer after charge and was not developed. Three possible fluid fill scenarios were investigated: a) tilted contact due to structural changes post-charge, b) imbibition of the deeper interval, c) primary drainage with field-wide flat contact related to the second pulse of charge. Each scenario impacts the development of the three units positively or negatively. Water saturation logs vs. True Vertical Depth plots were the main diagnostic tool used to rule out fluid fill scenarios. The plots were used to recognise lateral changes of the saturation profile and investigate imbibition signatures. Production data were also used to cross check the expected fluid fill scenario. The resistivity tools’ types and mud resistivities were examined.
Locate the Remaining Oil ltro and Predictive Analytics Application for Development Decisions on the Z Field
Authors: Masini Cristian , Al Shuaili Khalid Said , Kuzmichev Dmitry , Mironenko Yulia , Majidaie Saeed , Buoy Rina , Alessio Laurent Didier , Malakhov Denis , Ryzhov Sergey , Postuma Willem
Published: September 2019

Unlocking the potential of existing assets and efficient production optimisation can be a challenging task from resource and technical execution point of view when using traditional static and dynamic modelling workflows making decision-making process inefficient and less robust.

A set of modern techniques in data processing and artificial intelligence could change the pattern of decision-making process for oil and gas fields within next few years. This paper presents an innovative workflow based on predictive analytics methods and machine learning to establish a new approach for assets management and fields’ optimisation. Based on the merge between classical reservoir engineering and Locate-the-Remaining-Oil (LTRO) techniques combined with smart data science and innovative deep learning algorithms this workflow proves that turnaround time for subsurface assets evaluation and optimisation could shrink from many months into a few weeks.

In this paper we present the results of the study, conducted on the Z field located in the South of Oman, using an efficient ROCM (Remaining Oil Compliant Mapping) workflow within an advanced LTRO software package. The goal of the study was to perform an evaluation of quantified and risked remaining oil for infill drilling and establish a field redevelopment strategy.

The resource in place assessment is complemented with production forecast. A neural network engine coupled with ROCM allowed to test various infill scenarios using predictive analytics. Results of the study have been validated against 3D reservoir simulation, whereby a dynamic sector model was created and history matched.

Z asset has a number of challenges starting from the fact that for the last 25 years the field has been developed by horizontal producers. The geological challenges are related to the high degree of reservoir heterogeneity which, combined with high oil viscosity, leads to water fingering effects. These aspects are making dynamic modelling challenging and time consuming.

In this paper, we describe in details the workflow elements to determine risked remaining oil saturation distribution, along with the results of ROCM and a full-field forecast for infill development scenarios by using neural network predictive analytics validated against drilled infills performance.
The Decomposition of Volumetric Sweep Efficiency and Its Utility
Authors: AlSofi Abdulkareem M. , Blunt Martin J.
Published: September 2019

The traditional definition of volumetric sweep efficiency sums the effects of both fingering (arising due to contrasts in mobility) and bypassing (arising due to contrasts in permeability as well as well placement). Accordingly, we cannot quantitatively attribute poor sweep to either bypassing or fingering. Similarly, in EOR, the incremental recovery cannot be quantitatively associated with the reduction of those effects. For such purposes, we rely on visualization and mapping of saturation profiles to quantify and characterize the remaining oil in place including its distribution. . In this work, we propose a complementary method to obtain an instantaneous insight of the remaining oil distribution. We demonstrate the decomposition of fingering and bypassing effects and its utility. We first redefine recovery factors such that we decouple bypassing and fingering effects. We then validate those redefined sweep indicators by examining a 5-spot waterflood and two idealistic polymer floods. Later, we demonstrate the possible utility of those redefined sweep indicators through different examples. In one example, we compare the performance of a shear - thinning polymer to a recovery-equivalent Newtonian polymer. Using fingering and bypassing sweep indicators, we can immediately conclude that the shear-thinning polymer exacerbates bypassing. We recommend the adoption of our redefined sweep indicators in any simulation suite. They provide instant understanding of sweep and hence can be complementary to standard practices of oil saturation mapping and of special value when analyzing the results of multiple realizations and/or development scenarios.
Numerical Simulation of Non-Equilibrium Phase Behavior of Hydrocarbons for Modeling Oil and Gas Fields with Gas Injection
Authors: Al-Jenaibi Faisal , Bogachev Kirill , Milyutin Sergey , Zemtsov Sergey , Gusarov Evgenii , Kuzevanov Maksim , Indrupskiy Ilya
Published: September 2019

This paper deals with the issues related to the modeling of non-equilibrium phase transition in isothermal compositional models. Based on a real case of oil and gas field in the Middle East, the importance to take into account the effects of thermodynamic non-equilibrium are demonstrated with the help of mathematical models proposed earlier.

Theoretical and experimental studies, as well as actual field development data, show that not all phase transition processes take place in the forward and reverse directions at the same rate. For example, the dissolution of gas is much slower than the gas liberation from oil. Non-equilibrium processes are those whose characteristic time is comparable to or exceeding the characteristic time of variation of external conditions. In the classical formulation, it is supposed that thermodynamic processes are equilibrium, but the effect of non-equilibrium in addition to large grid cell sizes of the dynamic model and small-time steps can significantly affect the simulation results. In the case of black oil models, there are extensions of the mathematical model that are often used to describe the non-equilibrium behavior. At the moment, the rate of establishment of thermodynamic equilibrium is not taken into account in the majority of compositional models, the neglection of which in some cases might question the reliability of the simulation results. The practical implementation of the ideas (Indrupskiy et al, 2017), which were stated about how to take into account the non-equilibrium of thermodynamic processes occurring in the reservoir for compositional models, is performed.

The paper presents the results of modeling gas and water injection as a method of pressure support after development under depletion. In the equilibrium approach gas dissolves in oil at gas-oil contact simultaneously with increasing pressure. In practice, gas dissolution in oil occurs extremely slowly, and the dissolution rate decreases as the pressure approach the saturation pressure of the oil. According to laboratory studies, the modeling of such phase transitions requires the implementation of non-equilibrium models. At the same time, usage of the equilibrium models for this type of field leads to dramatic errors in estimates of the oil recovery.
Ultrafast Core Analysis for Tight Gas Reservoirs
Authors: Bona Nicola , Santonico Dario , Machicote Saida , Battigelli Alessandra
Published: September 2019

For oil and gas companies, accelerating the time to first hydrocarbon is a strategic objective. Special core analysis programs for tight gas reservoirs may take many months because of the long equilibration times involved in the tests. This represents a bottleneck for achieving the goal of reducing the time-to- market. Both log interpretation and reservoir modelling activities are impacted by the long SCAL durations. In order to face the challenge, a suite of fast methods have been developed. They are fast because they operate under non-equilibrium conditions. The methods give the m&n parameters for electric log interpretation, the endpoint gas relative permeability and the relationship linking initial gas saturation, trapped gas saturation and endpoint water relative permeability in a couple of days.
An Efficient Approach to Diagnose and Improve 3D Reservoir Model Quality in a Highly Diagenetic Deterogeneous and Dynamic Pressure Carbonate Field Case Study
Authors: Susanto Maria Indriaty , Sellar Christopher , Contreras Perez David
Published: September 2019

This paper presents a diagnostic workflow to understand and implement rock and fluid modeling in a diagenetically heterogeneous and hydrodynamically pressured Middle East carbonate field. The workflow allows interactive field data integration, provides guidance for reservoir property distribution and fluid contact generation in order to improve reserves and forecasting estimation. The workflow is useful to a reservoir modeler in QA/QC role and in this case it proves particularly applicable in an organization with constrained resources during the farm-in process. The workflow runs on numerical methods within the static model to avoid database discrepancy during the diagnostic process. Using the core (CCAL, SCAL), log and pressure database, the geoscientist can assess subsurface modeling outputs from the simplest to more complex deterministic scenarios. The process aims to minimize the discrepancy between data input and model output while continuously honoring the data, maintaining realistic correlations (e.g. between static permeability and water saturation) and respecting inherent uncertainty.

Using a data-rich Middle East carbonate reservoir, the pre- and post-diagnostic comparison of 3D modeled reservoir properties to the input data are demonstrated. Diagnostic steps have helped to understand potential subsurface scenarios and thus minimize the discrepancy post exercise. The value of the workflow is its ability to pinpoint the key uncertainties in rock and fluid modeling from the field’s vast dataset in a shorter diagnostic time. The application of the workflow in this carbonate reservoir case study increases the importance of geological and property driven rock type classification and its 3D distribution in matching the water saturation profile. This proved particularly challenging in this case study due to the field’s compartmentalization - fluid contact scenario.
Reservoir Simulation Model With Surfactant Flooding Including Salinity and Thermal Effect, Based on Laboratory Experiments
Authors: Preux Christophe , Malinouskaya Iryna , Nguyen Quang-Long , Flauraud Eric , Ayache Simon
Published: September 2019

In order to improve the oil recovery factor, many oil companies employ surfactant in injected water. On one hand, the injection of surfactant influences the interfacial tension and to a lesser extent, the mobility reduction factor. On the other hand, the efficiency of the surfactant depends strongly on the salinity and temperature conditions. In order to optimize the surfactant injection procedure, the salinity and temperature effects are commonly studied through series of laboratory experiments. However, these types of experiments are often long and expensive. Therefore, engineers use numerical simulations. The present study addresses a numerical model, which allows to take into account the modifications of the interfacial tension (IFT) and the mobility reduction factor due to the salinity and temperature variations during the surfactant injection.

In this work, we propose a coupled numerical model based on five equations: i) two transport equations of water and oil phases modelized by the Darcy's law, ii) two transport equations for the surfactant and the salinity (the surfactant and the salinity are transported only in the water phase) iii) one energy conservation equation to take into account the thermal effect on surfactant flooding. The system of equations includes the salinity and the temperature impacts on the surfactant adsorption and thermal degradation, as well as the interfacial tension. Thus, this model allows improving the analysis of thermal corefloods or reservoir operations resulting from the surfactant injection.

The coupled model is used to reproduce laboratory experiments based on corefloods. We analyze the interaction phenomena between the surfactant, salinity and temperature. Then, we demonstrate a competition between two phenomena: the thermal effect on the viscosity of water on one hand, and the effect of surfactant on the mobility of water on the other hand. This study highlights the efficiency of numerical simulations for the analysis and choice of the surfactant applied to the given reservoir and well conditions.

Obviously, the knowledge of IFT and its dependence on surfactant concentration, salinity and temperature is not sufficient to understand all the physical mechanisms involved in a coreflood study. The phenomena are in fact extremely coupled, and the reservoir simulator coupling all these effects is found to be very helpful for engineers in order to take a good decision about the surfactant species to be used.
A Parallel Load-Balancing Reservoir Simulator with Dynamic Mesh Optimisation
Authors: Salinas Pablo , Jacquemyn Carl , Kampitsis Andreas , Via-Estrem Lluis , Heaney Claire , Pain Christopher , Jackson Matthew
Published: September 2019

The use of dynamic mesh optimization (DMO) for multiphase flow in porous have been proposed recently showing a very good potential to reduce the computational cost by placing the resolution where and when necessary. Nonetheless, further work needs to be done to prove its usability in very large domains where parallel computing with distributed memory, i.e. using MPI libraries, may be necessary. Here, we describe the methodology used to parallelize a multiphase porous media flow simulator in combination with DMO as well as study of its performance. Due to the peculiarities and complexities of the typical porous media simulations due to its high aspect ratios, we have included a fail-safe for parallel simulations with DMO that enhance the robustness and stability of the methods used to parallelize DMO in other fields (Navier- Stokes flows). The results show that DMO for parallel computing in multiphase porous media flows can perform very well, showing good scaling behaviour.
Field Application Study on Automatic History Matching Using Particle Swarm Optimization
Authors: Lee Sanghyun , Stephen Karl, Dunbar
Published: September 2019

The traditional trial and error approach of history matching to obtain an accurate model requires engineers to control each uncertain parameter and can be quite time consuming and inefficient. However, automatic history matching (AHM), assisted by computers, is an efficient process to control a large number of parameters simultaneously by an algorithm that integrates a static model with dynamic data to minimize a misfit for improving reliability. It helps to reduce simulation run time as well.

Particle Swarm Optimization (PSO) is a population based stochastic algorithm that can explore parameter space combined with the least squares single objective function. The process of AHM can adopt parameterization and realization methods to reduce inverse problems. In this study, realizations of various reservoir properties such as porosity, net to gross, relative permeability, horizontal and vertical permeability, and aquifer size were chosen for controlling throughout the AHM. History matching was conducted to validate the efficiency of each method. The guidelines for optimized AHM with a stochastic algorithm are also disccussed.

The realization and parameterization methods improved matching results in a full-field application with resulting in a reduced misfit and in less. A stochastic algorithm generates multiple models to deduce control parameters to reduce a misfit. In this study we identified that PSO converged effectively with updated control parameters. The optimized AHM improved the accuracy of a full-field model although some misfit remained in the match to bottomhole pressure.

We found that updating with too many parameters makes the problem difficult to solve while using too few leads to false convergence. In addition, while the simulation run time is critical, a full-field simulation model with reduced computational overhead is benefitial.

In this study, we observed that the PSO was an efficient algorithm to update control parameters to reduce a misfit. Using the parameterization and realization as an assisted method helped find better results. Overall this study can be used as a guideline to optimize the process of history matching.
Dynamic Modeling of a High Temperature CO2-Rich Giant Gas Field with a Carbon Capture and Storage Strategy
Authors: Rizzato Paolo , Castano Daniele , Moghadasi Leili , Renna Dario , Pisicchio Patrizia , Bartosek Martin , Suhardiman Yohan , Maxwell Andrew
Published: September 2019

This paper describes the results of an integrated reservoir study aimed at producing hydrocarbons through a sustainable development from a green High Temperature (HT) giant CO2-rich gas field in the Australian offshore. The development concept addressed the complex challenge of exploiting resources while minimizing the carbon impact.

In order to characterize the reservoir in the most detailed way and to describe the fluids behaviour, a 1.8 million active cells compositional model has been built. An analytical aquifer has been coupled in order to represent the boundary conditions of the area.

The faults system, interpreted on seismic data by geophysicists, has been included in the simulation model. The selected development plan includes the re-injection of the produced CO2 into the aquifer of the reservoir itself. The supercritical CO2-brine relative permeability curves at reservoir conditions have been provided by Eni laboratories, where the experiments were performed.

Therefore, a detailed model has been built with the purpose of: –Defining producing well and CO2 injector well locations, numbers and phasing to evaluate expected CO2 injectivity and CO2 breakthrough issues;–Optimizing the development concept through a risk analysis approach;–Estimating the CO2-rich gas injectivity and storage capacity in the saline aquifer of the reservoir;–Predicting the behavior of the CO2-rich gas after re-injection (breakthrough timing and plume migration);–Maximizing the CO2 sequestration in the reservoir.
EOR Technologies and Applications Towards 70% Recovery Factor Aspiration in Giant Carbonate Middle East Reservoirs
Authors: Al-Keebali Aaesha , Yaslam Maged , Bin Amro Ahmed , Masalmaeh Shehadeh
Published: September 2019

As part of enhanced oil recovery (EOR) strategic objectives to boost oil recovery towards 70% aspiration and demonstrate EOR as an attractive viable option for environmental Carbon Capture, Utilization and Storage (CCUS) applications, various conventional and novel EOR technologies and applications are being screened and studied to ensure meeting mandated objectives. Accordingly, number of EOR pilots and projects have grown substantially over recent years to ensure derisking the full field expansion uncertainties and challenges, especially in such carbonate reservoirs with harsh conditions of temperature (~ 250 F) and salinity (~ 200,000 ppm).

Detailed screening study and performance review assessment have been conducted, in which gas and chemical based EOR technologies were identified for targeted reservoirs. The candidate reservoirs have a long history of EOR projects focusing on miscible hydrocarbon gas (HC) as early as 1996, which has supported oil production meeting forecast demand. On the other hand, as part of environmental driven strategy for CCUS and EOR applications, CO2 technology has been successfully progressing as EOR business case full-integrated cycle from pilot to field expansion during 2009-2016. In 2016, Al Reyadah has been launched as a unique commercial- scale CCUS facility in the region, that captures 800,000 tonnes of CO2 annually from Emirate Steel Industries and injects it into oilfields to boost crude recovery.

Furthermore, novel EOR technologies have been screened and identified with significant potential added value, that includes SIMGAP, SIWAP, Surfactant, Polymer and others, which are currently under modeling and design phase for implementation within upcoming few years to boost recovery factor towards 70% aspiration.

Development and piloting of latest technologies are among the main enablers to ensure fit-for purpose applications, proper planning and optimum design for ultimately maximum revenue economically. This paper presents a big-picture overview of EOR technologies with the focus on some cases, challenges and opportunities for super giant carbonate reservoirs.
History Matching of Multiple Wells With Actual Downhole ICD Configuration in a Five-Spot Pattern Reservoir Development
Authors: Altaf Basit , Allouti AbdelKader , Kedia Rachit
Published: September 2019

Downhole control devices are being widely implemented in fields globally; and, because of the costs involved in their implementation, a robust reservoir performance forecast is necessary. A prerequisite to a sound reservoir development plan is to have a robust history-matched reservoir simulation model. This study involves use of a downhole inflow control device (ICD) well configuration in the reservoir simulation model to perform history matching of a green-field offshore Abu Dhabi. The results of this approach are compared to the results from traditional approaches. The scope of this study is to examine the differences in both history match approaches.

Reservoir A is one of the major reservoirs of a green-field located offshore Abu Dhabi, and is being developed with a five-spot water injection pattern. The producers and water injectors are horizontal wells, which are drilled across different flow units within the reservoir. Because the reservoir is heterogeneous across all the flow units, the injection pattern results in a non-uniform water front. The conventional approach to history matching the well performance is to implement a positive skin factor across the well completions to mimic the effect of the inflow control devices (ICDs) installed in the well: increasing the pressure drop (ΔP) between the formation and the well tubing. In this study, the actual downhole configuration was prepared using well-completion analysis software, followed by use of a next-generation reservoir simulator to run the full field reservoir model for the history matching period.

As the field is being developed on the principles of digital concept, continuous high-frequency downhole pressure data is available in flowing as well as shut-in conditions. The use of this data, coupled with direct modeling of the ICDs in the simulation model, resulted in a significant improvement in the reliability of the history match, as compared to traditional approaches.

This study compares two history matching approaches for fields with wells completed with downhole control devices. The core purpose of this study is to integrate the principles of the digital oil field with conventional history matching techniques, with the ultimate goal of improving the history match.
An Enhanced NMR Workflow for Heterogeneous Carbonates Characterization, Offshore Abu Dhabi
Authors: Serry Amr , Yousif Sharifa , Abouzaid Ahmed , Kieduppatum Piyanuch , Soliman Ahmed
Published: September 2019

Full field development of the Upper Jurassic carbonates, offshore Abu Dhabi is exceedingly challenging. The heterogeneous texture, complicated pore systems and intensive lithology changes all mark the regressive cycles of sedimentation. Such complicated characteristics obscure formation evaluation of these formations. Advanced well logging tools and interpretation methodologies are implemented to minimize the petrophysical uncertainties to qualify the products as field development critical elements. This case study highlights a newly applied NMR log interpretation approach. The results help to understand the complex pore system in a tight carbonate layer, along a horizontal drain drilled close to the oil-water contact.

NMR log data was acquired in real-time while drilling simultaneously with Gamma Ray, Resistivity and Image Logs. Earlier field studies recommended swapping standard T2 free fluid relaxation cutoff values by actual laboratory NMR measurements for a higher precision suitable for the reservoir texture heterogeneity, the study itself supported the application of higher cutoff values to better discriminate the free fluid in well-connected macro pores from the irreducible which will have a direct impact on the computed permeability.

In this case study, a variable free-fluid T2 cutoff was firstly implemented based on arbitrary estimations to match the computed Coates permeability to the offset core values. Free-fluid, irreducible fluids were sequentially computed. A unique NMR-Gamma Inversion (NMR-GI) workflow is further utilized as a mathematically defined approach to process the raw data using probabilistic functions. The result is a more precise pore size distribution, coherent with the geological variations. NMR Capillary pressure was computed.

The complex formation texture could be accurately tracked for thousands of feet drilled along the horizontal drain. After validation with offset core, the NMR-GI interpretation was combined with, Archie saturation and Image log analysis for a conclusive assessment. Hydraulic flow units were combined. Successful completion design and production zone selection articulated on the defined open hole log interpretation.

NMR while drilling logging and the applied (NMR-GI) methodology prove to be leading tools to assist in resolving carbonate reservoir complexities. Not only that they help to understand the pore system characteristics, but they effectively support well placement, completion and production.