bluuebunny/crossref_metadata_2025 huggingface dataset:
VALORACIÓN ENERGÉTICA DE NUEVOS ALIMENTOS PARA TRUCHAS ARCO IRIS (Oncorrynchus mykiss)
Authors: ARANIBAR ARANIBAR MARCELINO JORGE , CALMET URIA ENRIQUE , ROQUE HUANCA BERNARDO
Published: July 2015

La investigación consistió en determinar el contenido de energía digestible (ED) de materias primas noveles (MPN) en truchas arco iris (Oncorhynchus mykiss). Se consideró una dieta base con harina de pescado y 10 dietas experimentales que incluyeron 70% de la dieta base y 30% de las MPN vegetales (harinas de quinua, cañihua, kiwicha, tarwi, trigo, sacha inchi y nuez de Brasil) y el sub-producto animal (harina de pota). La ED fue determinada mediante experimentos de digestibilidad convencional con el método indirecto, utilizando cenizas insolubles en acido como marcador indigestible (Hyflo Super Cel®). En la prueba de digestibilidad se utilizaron 180 truchas juveniles de 93 g de peso vivo y 20 cm de longitud total. Las truchas fueron distribuidas al azar en 9 tanques de 500 L de capacidad. Para la prueba de digestibilidad de las MPN se consideraron periodos de 14 días (7 de acostumbramiento y 7 de colección de heces) y en cada periodo se determinó la digestibilidad de 3 dietas con 3 repeticiones cada una. El contenido energético de los alimentos y las fecas colectadas fue determinado con un Calorímetro de bomba Parr Instruments 1341®. La energía digestible (ED) fue calculada mediante una ecuación que involucra las energías del alimento y las heces y las proporciones de la dieta base y las materias primas noveles. Los resultados fueron analizados utilizando la estadística descriptiva, un análisis de varianza y la prueba de Tukey para comparar las medias de las ED de las MPN. La harina de pota, la harina de lupino y la harina de sacha inchi tuvieron mayor contenido de ED (4,515; 4,279 y 3,992 cal/g; respectivamente), en relación a las otras materias primas. En conclusión, podemos afirmar que la energía digestible de la harina de pota, la harina de sacha inchi y la harina de lupino fueron mayores que las de los otros alimentos estudiados.

 

Palabras clave: digestibilidad, alimentos, energía digestible, truchas.
EFECTO TOXICOLÓGICO DEL JINCHO JINCHO (Heracium neoherrerae), ALTAMISA (Ambrosia arborescens), DIENTE DE LEÓN (Taraxacum officinale), HUIRA HUIRA (Pseudognaphalium spicatum) Y MISHICO (Bidens andicola) EN RATAS (Wistar)
Authors: MACHACA FIORELA
Published: July 2015

El objetivo: Determinar el efecto toxicológico de «jincho jincho», «altamisa», «diente de león», «huira huira» y «mishico» en ratas Wistar. Diseño: estudio experimental. El lugar: la Universidad Nacional del Altiplano - Puno, Facultad de Ciencias Biológicas y Veterinaria y Zootecnia durante 3 meses que evalúan el de toxicidad subcrónica con 5 mg del substrato pulverizado de cada planta en las ratas. El material biológico: ratas Wistar de ambos sexos y las 5 plantas mencionadas. Métodos: para la identificación de los metabolitos secundarios de las plantas, se realizó el método de Screennig Fitoquímico, para las pruebas toxicológicas se agrupo 1 grupo control y 5 grupos tratados dónde las dosis de 5mg/kg/d/3 meses eran aplicadas vía oral, se hicieron las observaciones clínicas diarias y el peso corporal. Los resultados: en las pruebas fitoquímicas se evidencio la presencia de los alcaloides con más intensidad en «altamisa» esto indica que esta planta muy fuerte para el consumo porque produce síntomas indeseados, durante el estudio toxicológico fue sacrificado una rata del grupo del extracto de «altamisa» debido al prolapso uterino, las síntomas clínicos descritos se distribuyeron de la siguiente manera: las ratas administradas con «altamisa» causó prolapso uterino, orquitis y deficiencia en el peso, con «mishico» causó somnolencia, con «huira huira» se produjo la irritación del ojo, con «diente de león» la irritación nasal, con «jincho jincho» el edema en el área del cuello. En las pruebas hematológicas en los parámetros había diferencia significativa, mientras que en la hemoglobina era menor en las ratas administradas con «altamisa.» Conclusión: la administración oral de los tres meses para los extractos de las plantas medicinales produjo la toxicidad por la planta «altamisa» calificándose como tóxico debido ala presencia de más síntomas y alcaloides.

PALABRAS CLAVE: * toxicológico * fitoquímica * síntomas clínicos * hematología.
ESTUDIO PETROGRÁFICO DE STOCK DE CABANILLAS – PUNO
Authors: MACHACA HANCCO ERNESTO
Published: July 2015

En la localidad de Cabanillas – Puno; el estudio petrografía cuerpo magmático permiten determinar, la clasificación de la roca de composición intermedia; identificación modal de minerales formadores, durante el año 2014; así como habito, forma, textura y tamaño de granos; entre otros determinar con claridad los ensambles y alteraciones minerales presentes en las muestras analizadas. La metodología aplica fue analítica y descriptiva de quince secciones finas preparadas de la tonalita. El objetivo principal es determinar la composición mineralógica del stock y los posibles eventos magmáticos durante la formación del cuerpo intrusivo es investigar e identificación los minerales formadores de roca. El resultado del análisis modal es: de plagioclasas (42%), sanidinas (10%), cuarzo (15%), augita (10%), biotita (10%), hornblenda (6%), minerales opacos (3%) y minerales de alteración (4%); entre los principales minerales de alteración se tiene a sericitas, caolinitas, pirofilitas, cloritas, que se encuentran en los espacios intergranulares de los minerales esenciales que llegaron a formar el stock de Cabanillas. Según los componentes principales se ha clasificados roca ígnea intermedia de textura holocristalina, fanerítica con fenocristales idiomorfos de oligoclasas; estos cristales presentan maclas de Carlsbad, polisintética; con una zonación concéntrica típica de las plagioclasas en magmas félsicos a intermedios. Los fenocristales idiomorfos de plagioclasas compuestas de maclas, con una zonación concéntrica de tres núcleos, determinan la pulsación de hasta tres eventos magmáticos, ocurrido durante el proceso de formación y cristalización del ascenso del magma.

PALABRAS CLAVE: * roca ígnea * composición * eventos magmáticos
EVALUACION DE LA DISPONIBILIDAD HÍDRICA ACTUAL Y FUTURA EN EL CONTEXTO DEL CAMBIO CLIMATICO EN LAS CUENCAS ILAVE Y RAMIS
Authors: LUJANO LAURA EFRAIN , DIAZ AGUILAR RENNY DANIEL , LUJANO LAURA APLORINARIO , QUISPE ARAGON JOSE PITAGORAS
Published: July 2015

La investigación, se realizó en la región hidrográfica del Titicaca (lado peruano), cuyo objetivo fue evaluar la disponibilidad hídrica actual y futura en el contexto del cambio climático, donde se analiza la distribución temporal de la precipitación simulada en el Centro Hadley del Reino Unido con una base climática de 1961 – 1990 y con proyecciones para el horizonte 2071 – 2100. Para el modelamiento de caudales, se utilizó el modelo hidrológico mensual de 2 parámetros, cuyas evaluaciones estadísticas fueron medidos a través de la eficiencia de Nash y Sutcliffe. Los resultados de las precipitaciones, simularon con precisión los patrones del ciclo estacional, sin embargo fueron sobreestimadas en comparación con las observadas durante todo el año, con un BIAS=55.7% y 169.6% para las cuencas Ilave y Ramis, indicando para finales del siglo XXI una reducción de precipitaciones en la cuenca Ilave y un incremento en la cuenca Ramis. En cuanto a los caudales, los resultados de calibración para los ríos Ilave y Ramis indican calificativos de aceptable y bueno, con eficiencias de Nash igual a 0.727 y 0.833 y en la fase de validación un Nash igual a 0.78 y 0.91 respectivamente. Las simulaciones futuras de descargas muestran el mismo patrón de cambio que las precipitaciones, con variaciones en promedio anual de A2=-29.3% y B2=-28.1% de disminución en la cuenca Ilave y con incrementos de A2=18.8% y B2=6.0% para la cuenca Ramis. Se observó que la mayor reducción del recurso hídrico se dará en la zona sur de la región hidrográfica del Titicaca.
ABSTRACT
CARACTERIZACIÓN PETROGRÁFICA DE LAS ROCAS DE LA ISLA ESTEVES PUNO
Authors: CALCINA MIGUEL , APAZA CAMPOS ROLANDO
Published: July 2015

La Isla Esteves - Puno está emplazado en un basamento rocoso constituido por rocas sedimentarias no clásticas y stock intrusivo. El propósito del presente estudio es caracterizar las rocas petrográficamente, para identificar los minerales constituyentes y las relaciones texturales entre los minerales, para su posterior clasificación según las nomenclaturas internacionales. Se tomó muestras representativas de tres tipos de rocas que afloran en la zona de estudio: calizas, calizas alteradas y roca intrusiva para análisis microscópico en el laboratorio e identificación de los minerales que las componen, los cuales fueron descritos según sus características físicas, morfológicas (forma, habito, clivaje, fractura, zonación, maclas) y ópticas (color, pleocroísmo, relieve, extinción, color de interferencia) así, como las texturas y microtexturas. Con los resultados del análisis modal se determinó el tipo de roca intrusiva como: cuarzo monzodiorita anfibol de textura porfídica, con una mineralogía de cuarzo fino, feldespatos y plagioclasas alteradas a sericitas; anfíboles alterados a cloritas y epidotas con presencia de minerales opacos. Las rocas carbonatadas son de composición mudstone de textura micrítica con venillas de calcita. Las rocas metasedimentarias son de composición packstone de textura granosoportado de naturaleza skarn. Respecto a la composición del intrusivo este fue originado por un magmatismo calcoalcalino enriquecida en elementos volátiles como azufre, hierro.
TRATAMIENTO CON PASTA ENDODONTICA UNA– PUNO
Authors: MANZANEDA PERALTA MARCO HERMINIO , MANZANEDA PEÑA PAOLA , MANZANEDA PEÑA ALINA
Published: July 2015

Resumen
Existen diferentes tipos de pastas endodonticas, que son escasas en el mercado, ya sea por la falta de conocimiento del odontólogo o por su dudosa respuesta al tratamiento. La investigación pretendió cubrir la falencia citada; previo consentimiento libre e informado de los 50 pacientes que llegaron al consultorio se le aplicó la fórmula de pasta endodontica UNA PUNO preparada localmente, utilizando eugenol y paramonoclorofenol alcanforado (líquidos) y por otro lado la acción sólida iodoformo, tetraciclina, óxido de zinc, hidróxido de calcio (para piezas dentarias caducas), de abril a octubre del 2013. En el periodo de tratamiento y seguimiento se les tomó radiografías para ver que no haya ninguna reacción adversa en el tratamiento realizado. A comparación con otras PASTAS ENDODONTICAS, el producto aplicado actuó como agente anti bacteriana y bacteriostático que van a destruir los residuos microbianos. Los resultados obtenidos son determinantes al haberse conformado el campo aséptico y ser más efectiva y económica a comparación de otros, bajando el costo de tratamiento endodontico y de mayor acceso a la población de escasos recursos económicos.

PALABRAS CLAVE: * pasta endodontica * UNA-PUNO * hidróxido de calcio * yodoformo * tetraciclina * oxido de zinc * eugenol
ABSTRACT
TREATMENT WITH ENDODONTIC TOOTHPASTE UNA-Puno

There are different types of endodontic pastes, which are scarce in the market, either by dentists’ lack of knowledge of the pastes existence orbecause of unknown effects of treatment on the patient. This research aimed to cover the knowledge gap discussed here. Prior the informed consent of the 50 patients who came to the clinic. We applied endodontic paste formula «UNA Puno» prepared locally using eugenol and camphor paramonochlorophenol (liquid) and secondly the solid iodoform reaction, tetracycline, zinc oxide, calcium hydroxide (for deciduous teeth). In the treatment period and follow-up, radiographs were taken to ensure no adverse reactions to the treatment. In comparison with other endodontic pastes, the product presented acts asan anti bacterial and bacteriostatic agent that destroys microbial residues. The obtained results are crucial, having defined an aseptic space; proven more effective and economical compared to other pastes. This lowers the cost of endodontic treatment while giving greater access to low-income populations.

KEY WORDS: * endodontic paste * «UNA-Puno» * calcium hydroxide * iodoform * tetracycline * zinc oxide * eugenol
IMPACTO DE LA CADENA PRODUCTIVA DE LA QUINUA EN EL DISTRITO DE CABANA REGION PUNO
Authors: FLORES ADA LUZ , CHURA ERNESTO
Published: July 2015

El presente trabajo de investigación se realizó en el distrito de Cabana región Puno. Los objetivos fueron: Determinar el impacto de la cadena productiva de quinua en el distrito, y Proponer estrategias para la sostenibilidad de la cadena productiva de quinua, Se aplicó un cuestionario para medir las características socio económicas, tomando una muestra de 39 productores de este cultivo. Se ha analizado la cadena comercializadora y la estructura de la cadena productiva de quinua. Los resultados señalan que existe un impacto directo de los componentes de la cadena productiva de quinua en distrito de Cabana; se han identificado que los productores en su mayoría son de sexo femenino, el rendimiento oscila entre 1200 a 750 kg/ha, la producción destinan a la venta y venden a la Asociación Central de Productores Multisectoriales de Cabana – ASCENPROMUL cada quincena la cantidad de 2 a 4 arrobas a precio S/ . 50.00, la ganancia de la venta dedican a la educación de sus hijos, la situación económica es regular en comparación de años anteriores, obteniendo una ganancia que oscila S/.200.00 a S/.400.00, las tierras que disponen para la producción son heredadas de sus padres, usan el estiércol del ganado como abono, por ultimo están dispuestos a producir quinua en los años venideros. La comparación entre la estructura de cadena productiva actual con el futuro de la misma, se infieren estrategias que permitirán pasar de la actual situación productiva, tecnológica, organizacional y comercial, en alianzas estratégicas entre productores y procesadores regionales, el ritmo y orientación estará dado por actores de otras regiones. Por tanto la matriz insumo-producto es un tipo de análisis más importante de los modelos, ya que permite estimar los insumos directos requeridos para satisfacer un nivel de demanda de la producción de la quinua.
LOS SABERES ANCESTRALES EN LA ERA DELANTROPOCENO: HACIA UNA TEORÍA DE TEXTUALIDAD ALTERNATIVA DE LOS PUEBLOS ORIGINARIOS DE LA AMAZONIA
Authors: UZENDOSKI MICHAEL A
Published: July 2015

La arqueología nos indica que los pueblos amazónicos habían desarrollado sociedades complejas en el alto Napo (Porras 1985) y en otros sitios miles de años antes del nacimiento de Cristo (Whitehead 2009). Aunque la evidencia arqueológica es escasa en muchos lugares podemos afirmar que los Amazónicos han aportado mucho a la humanidad, incluyendo tales descubrimientos como: la domesticación de la yuca, conocimiento sobre miles de plantas medicinales, el manejo y mejoramiento de la biodiversidad de la selva con técnicas de agricultura de pequeña escala con patrones de caza y pesca— y numerosos otras maravillas como la chicha (las mujeres de laAmazoniaAltadeNapo saben haceralgunasclasesdechicha, todas ricas), los famosos maytu (pescado asado en hoja de bijao), el uchú manga (una olla de ají mezclado con carne ahumado, cacao blanco), y los yuyu (palmito, tuta yuyu, helechos) que se come con la yuca. Pero, las culturas Amazónicas han hecho otros aportes a la humanidad más allá de la gastronomía y plantas medicinales.
Utilization of waste frying oils for transport fuel extender : Beneficial to the environment
Authors: Nagy Valéria
Published: July 2015

University of Szeged, Faculty of Engineering carried out research on behalf of Tisza Volán Company (integrated in Centre for South Great Plain Transport Plc.) which takes great care of environmental protection and sustainable management. So the fundamental objective of this research is to analyse utilization possibilities of used vegetable oils (waste frying oils derived from food production, food preparation) as fuels mixed into diesel fuel. This paper summarized the application possibilities, limitations, environmental impacts and difficulties of waste frying oils as fuels. The research points out that all action of different sizes of companies and behaviour of member of society are welcomed and they contribute to sustainable use of environment. This paper helps to expand the knowledge about the utilization of waste frying oils as fuels.
Jueces y política en democracia y dictadura. Lecciones desde Chile, de Lisa Hilbink
Authors: Cortés Salinas Josafat
Published: July 2015

Acceder al texto completo para consultar el contenido.
An integrated approach to understanding the linkages between ecosystem services and human well‐being
Authors: Yang Wu , Dietz Thomas , Kramer Daniel Boyd , Ouyang Zhiyun , Liu Jianguo
Published: July 2015

In order to use science to manage human–nature interactions, we need much more nuanced, and when possible, quantitative, analyses of the interplay among ecosystem services (ES), human well‐being (HWB), and drivers of both ecosystem structure and function, as well as HWB. Despite a growing interest and extensive efforts in ES research in the past decade, systematic and quantitative work on the linkages between ES and HWB is rare in existing literature, largely due to the lack of use of quantitative indicators and integrated models. Here, we integrated indicators of human dependence on ES, of HWB, and of direct and indirect drivers of both using data from household surveys carried out at Wolong Nature Reserve, China. We examined how human dependence on ES and HWB might be affected by direct drivers, such as a natural disaster, and how human dependence on ES and direct and indirect drivers might affect HWB. Our results show that the direct driver (i.e., Wenchuan Earthquake) significantly affected both households' dependence on ES and their well‐being. Such impacts differed across various dimensions of ES and well‐being as indicated by subindices. Those disadvantaged households with lower access to multiple forms of capital, more property damages, or larger revenue reductions also experienced greater losses in HWB. Diversifying human dependence on ES helps to mitigate disaster impacts on HWB. Our findings offer strong empirical evidence that the construction of quantitative indicators for ES and HWB, especially integrated models using them, is a viable approach for advancing the understanding of linkages between ES and HWB.
Litterfall as a niche construction process in a northern hardwood forest
Authors: Bigelow Seth W. , Canham Charles D.
Published: July 2015

Northern hardwood forests can exhibit considerable temporal stability in their species composition, which litterfall may help to maintain by modifying the soil environment to create an ecological inheritance. We evaluated the evidence for this niche‐construction perspective by carrying out a spatially explicit analysis of redistribution of calcium (Ca), magnesium (Mg), and potassium (K) via leaf litterfall of the six dominant tree species in a temperate forest in northwest Connecticut, USA. We combined stem maps with litterfall measurements to fit models of leaf litterfall for individual species, and we chemically analyzed leaves, surface soil extractions, and unweathered soil particles.

Analysis of elemental oxides in unweathered soil particles suggested that species did not differ in ability to gain access to rock‐bound nutrients. Nevertheless, species had a significant effect on quantity of Ca cycled in litter—the two calcicoles (species with affinity for calcium‐rich soils) occurred most commonly on the richest soils, and the Ca concentration in their senescent leaves increased sharply across the soil fertility gradient. No species effects on Mg or K redistribution were seen. Litter dispersal distances cut across calcium affinities: e.g., of the four calcifuges (plants with affinity for acidic soils) two had distant litter dispersal (modal dispersal distance ≥ 4 m) and two had close litter dispersal (modal dispersal distance < 0.3 m). Dispersal distance was associated with leaf size: the three species with the smallest leaves had the most concentrated litterfall shadows. One of these, eastern hemlock, has a recognized ability to exclude other species in part by creating an acidic low‐nutrient soil environment. Overall, the ability of trees to generate soil conditions that were aligned with their own resource use was expressed most clearly in the calcium content of their leaves. We concluded that tree‐environment interactions at the site displayed several of the criteria for niche construction.
The Synergy Effect of Microwave Heat and Demulsifier in Resolving Water-In-Oil Emulsions
Authors: Sulaimon Aliyu Adebayor , Umoh Etimbuk Bassey , Adeyemi Bamikole Joshua
Published: July 2015

Water-in-oil emulsions are unstable colloidal dispersions with water as the dispersed phase and oil as the continuous phase. Emulsion constitutes numerous problems in the oil and gas industry ranging from flow problems due to high viscosity of emulsions to increase in cost in the use of demulsifiers. In resolving emulsions, heat, chemical or a combination of both methods can be used.

In this study, synthetic emulsions in water-to-oil phase ratios (WOR) of 20/80 and 50/50 were resolved separately with heat generated from microwave oven, chemical demulsifiers and their combination.

Results show that as much as 70% water could be recovered from stable emulsions (WOR: 20/80) with an appropriate microwave power level while for weak emulsions (WOR: 50/50), complete water removal is possible with an effective demulsifier. Generally, the results show that the combined treatments by heat and chemical methods offer the best emulsion resolution.
Computation Of Dimensionless Pressure In A Vertical Well Using Gauss-Chebyshev Quadrature, Gauss-Kronrod Quadrature And Runge-Kutta Fourth Order
Authors: Oloro O. J , Okoh E.
Published: July 2015

The determination of pressure distribution in a vertical well using analytical methods have posed a problem to petroleum engineers due to its cumbersome equations and difficulty in programming in computer system. In this paper three numerical methods are used to determine dimensionless pressure, which are (Gauss-Chebyshev quadrature, Gauss-Kronrod quadrature and Runge-Kutta fourth order). There results were compared with the analytical solutions based on the following assumptions: (1) An infinite acting reservoir (2) the well is producing at constant flow rate (3) the reservoir is at a uniform pressure when production begins (4) the well is centered in a cylindrical reservoir at radius re and (5)No flow across the outer boundary. The result shows that as rD increases, PD decreases, this indicate that when the radius of the wellbore is increasing, productivity decreases for a vertical well. This work also show that the accuracy of the quadrature methods depends on the nth terms used and also increases with rD. That is at higher rD the quadrature methods approximate to the exact solution. Runge-Kutta fourth method was found to give exact solution at lower step time but required high computation time.
A Proposed Simplified Technique for Accurate Measurement and Calculation of Flared Gas Volume for Nigerian Oil fields
Authors: Ebuka Umeh , Chukwunonso Abonyi , Nnaemeka Nwanna , Princewill Ikpeka
Published: July 2015

In Nigeria, although the regulatory agencies in the oil and gas industry has placed some financial and cost measures to minimize the amount of gas flared by operating companies, some operators and contractors are yet to consistently report the amount of gas flared in their process plants. These shortcomings are partially due to inadequate application of gas flaring technologies owing to large turn down ratios caused by wide variations in operating conditions of temperature, pressure and flow rate. However, gas flaring is by no means a simple measurement process on its own. This is primarily due to the large variations in conditions often found in a flare stack. Measurement difficulty could also arise through the flare type (be it background, normal or blow-down), changes in the flow profile and Reynolds number caused by variation in the physical properties of the gases and errors due to installation effects. In order to fully appreciate the challenges involved in measuring flare gas volume, it is important to first appreciate these varying conditions and the effect they have on measurement.4

From the aforementioned points, it is clear that the accurate measurement of the flared gas is a rigorous and complex process with several challenges to be considered. This paper presents a simple to use, install and operate software, with high level of precision in accuracy for measuring flared gas volume based on PVs (pressure valves) present in process plants. A similar approach has been applied in South Pars gas development projects in Iran; utilizing the design information in PVs datasheet as well as actual plant data for opening percentage values which have been utilized from plant Distributed Control System (DCS) and PIMS PIMS ( Plant Integrated Management System) using excel and visual basic.5 However, in this study, a more robust software program that has the ability to extract data from the plant's DCS and PIMS server has been developed using Java, correlation used by this software was generated using Hysys for a particular process plant model in Niger-Delta and Microsoft Excel used to regress this correlation. An iteration time-step of 1440 minutes has been chosen for greater accuracy. Features of this program include flexibility, user friendly, cost-intensive and real-time. Assumptions made during these calculations were stated clearly in this paper.
Real-Time Production Optimization Experience in an Offshore Gaslifted Field
Authors: Ofonmbuk Umanah , Ifechukwu Michaels , Adebowale Oladepo David
Published: July 2015

The conventional approach of calibrating and updating well models is time consuming. Because of the dependency of the field optimization software on updated well models, the conventional approach reduces the frequency of implementing the optimizer's recommendations.

To operate their fields at their maximum deliverability, taking into consideration all the system constrains, a real-time software/workflow, Intelligent Daily Operation (IDO) was proposed and implemented to monitor, automatically calibrate and update well models.

The question is will IDO and other tools be able to address all these?

The objective of this work was to evaluate IDO and other real-time optimization (RTO) tools that are present in the company, and to identify effective ways of optimizing production using these applications. The workflow is as follows:

Identify critical steps in the current workflow that can be improved by switching over to real time mode. Review the tools that are available for real time performance surveillance and optimization. Identify the scope and limitations of IDO. Suggest ways of using field data source to monitor/validate result of IDO. Identify gaps and suggest ways of closing the optimization cycle.

The study reveals; average monthly savings of 380 engineering hours, achievement of daily update of well models as a result of implementation of RTO tools and after full implementation of RTO applications, monthly implementation of optimizer's recommendation will also be attained.

Certain limitations of the RTO were also identified, it includes inability of the models to match field operating conditions, possibility of erroneous readings from the multiphase meters, on which the production allocation function of the RTO applications depend.

The work further makes suggestions on how to use to the RTO applications for early detection of unhealthy wells, which improves efficiency.
Experimental Model for the Determination of Hydration Potential of Niger-Delta Shales for Drilling Mud Design
Authors: Eme C. , Dosunmu A. , Anyanwu C. , Okoro E. E. , Ekaide E.
Published: July 2015

Maintaining stability between shale-mud interaction is a key factor towards improving safety and drilling efficiency while minimizing costs associated with drilling and production operations. The use of conventional Water Base Mud in drilling shale formation results in the adsorption of water associated with the drilling mud by the shale. Depending on the shale type, water adsorption may lead to various reactions such as swelling, cuttings dispersion, and increase in pore pressure creating wellbore instability to varying degrees. This research provides information on shale characterization of two Wells, A and B in Niger/delta region Nigeria and proposes the development of inhibitive Water based drilling fluids for the shale samples. It also provide results of the shale mineralogy, native moisture content, total organic carbon content, cation exchange capacity and the adsorption isotherm of the shale samples. From the analysis, the X-Ray Diffraction (XRD) results indicate that the shales are dominant of kaolinite. The result of the CEC falls within the Kaolinites group of 3 Meq/100g - 10 Meq/100g according to Boulding and Ginn (2003). Polymeric fluids composed of varying Polymer/salt (KCl, NaCl and CaCl2) concentrations was prepared and evaluated for the shales samples using dispersion test. The result of the analysis was used to design a mud selection template for drilling through shales. Recommendations for improving shale stability were described, based on the current understanding of shale stability.
Effect of Grain Size on Porosity Revisited
Authors: Ogolo Naomi A. , Akinboro Olorunmbe G. , Inam Joseph E. , Akpokere Felix E. , Onyekonwu Mike O.
Published: July 2015

The sand grains of unconsolidated hydrocarbon bearing formations have been found to be well sorted. Porosity which is a very important parameter in estimating hydrocarbon reserves partly depends on the pore spaces between sand grains. In this work, the porosity values of well sorted and moderately sorted sands obtained from three different locations in the Niger Delta were determined. The results showed that porosity increases with decreasing grain size. It was generally observed that porosity increased from about 26% to 42% as the sand grain sizes decreased from 1000microns to 45microns. Theoretically, grain size does not affect porosity for well sorted grains but in nature, sand grain size affects porosity probably because sand grain deformation from a spherical shape increases with decrease in particle size. It is therefore suggested that attempts be made to use naturally deposited sand grain sizes to predict porosity based on the premise that particle shape affects porosity and particle sphericity decreases as grain size decreases and this accounts for the increase in porosity with decreasing grain size.
Mud Cap Drilling in a Highly Fractured HPHT Carbonate Formation: A Case Study in an Iranian Offshore Field Persian Gulf
Authors: Zoveidavianpoor Mansoor , Farahani Vahid
Published: July 2015

Significant and dangerous drilling problem is created when suddenly facing massive lost returns. Consequently, conventional means of controlling the well through circulation down the drill pipe and returning up the annulus becomes impossible. Due to their heterogeneous nature, carbonate rocks typically present drilling challenges. In M offshore field it is common to encounter tight formations, highly fractured rocks, and vugular textures. Accordingly, alternate means of controlling the well and safely drilling ahead must be used.

This paper reviews and discusses the application of mud cap drilling (MCD) which was used to drill a well in a highly fractured formation offshore Iran in Persian Gulf. The target formation in 12 ¼″ section of an appraisal well of Iran's M gas field shared with Saudi Arabia was a carbonate reef. This section contains highly fractured rocks and dissolution channels created by large caverns that partially collapsed with later sedimentation. When these dissolution channels were penetrated by the well path, the formation completely yielded to any small amount of pressure overbalance and complete loss of returns was experienced. Seismic analysis was not successful in clearly identifying these areas. All wells drilled into the target reservoir had the potential for this loss. All attempts at curing this lost circulation with conventional techniques failed. The logical way of approaching the problem and achieving total depth was to drill with MCD technique.

PETRPARS has recently implemented a MCD solution on one well offshore Persian Gulf, Iran, which experienced total losses. Once total losses are encountered, a series of procedures are executed that result in converting the well from a conventional drilling operation to a MCD operation. While drilling Well M03, PETROPARS encountered total lost in Surmeh and Neyriz formations from 7904 to 10184 feet. The consequent actions include trying to cure losses with lost-circulation materials, cementing, waiting on mud materials and enduring other drilling problems associated with massive losses encountered in the lower portion of the well. Full penetration of these formations requires the use of a MCD and consequently well cost was minimized due to application of this method. A comparison for the cost of drilling mud in 12 ¼″ section in well M03 shows 43.7% reduction when drilling shifted to MCD technique.

This paper discusses the operational and technical problems encountered including well control, optimizing mud composition and usage, and formation evaluation on an appraisal well which was drilled on this field. The geology, lithology and causes of loss also will be discussed at this paper.
Safeguarding Pressure Integrity of Surface Well Control Equipment: A Review of Fastlock Drilling Adapter and Blow Out Preventer Connection Failure in High Pressure Well
Authors: Awe S.O. , Erinle A. , Akinfolarin A. , Ibrahim T. , Obanya P. , Roes V.
Published: July 2015

Well control is primarily achieved using mud hydrostatic column to overbalance reservoir pressures. The overbalance from mud can be lost in a well due to following reasons; encountering unexpected higher pore pressure, reduction in mud column due to down hole losses, reduction in mud weight due to dilution and loss of hydrostatic head due to poor drilling practices. Emergency situation is created when escalation of any of the scenarios results to the loss of primary well control. In such instance, the secondary well control equipment such as blow out preventers and wellheads are activated to enable restoration of overbalance and return of drilling operation to normalcy. As part of emergency preparedness, it is important to regularly confirm the pressure integrity of the secondary well control equipment in order to guarantee their availability whenever required. As part of the pressure integrity assurance process in Shell operations, pressure test of the critical equipment is mandatorily carried out every 21days whenever the wellbore is exposed to hydrocarbon bearing reservoir.

Drilling operation has been successfully carried on GXH-1 HPHT well across the hydrocarbon bearing hydrostatic interval. Pressure test that was carried out on the well control equipment after installing the 9 7/8″ production casing and prior to drilling into the high pressure interval of the well revealed loss of pressure integrity at the flange connection between the 15,000psi rated BOP and fastlock drilling adapter on the 15,000psi rated wellhead. Upon observation, the loss of pressure integrity was discovered to be due to washout on the flanges of the BOPs and the wellhead as well as the ring gasket. The well was suspended with plug to allow safe repairs of the damaged flanges.

The damages on the flanges were successfully repaired and pressure tested to full rated working pressure before recommencement of drilling operation. This paper reviews the relevant drilling operations that preceded the loss of pressure integrity of the secondary well control equipment and the root cause analysis carried out on the failure. It also enumerates recommendations from lessons learnt from the incident that will ensure prevention of future re-occurrence of the type of failure.
A Review of Drill-Cuttings Treatment and Disposal Methods in Nigeria- The Gaps and Way Forward
Authors: Mkpaoro M. I. , Okpokwasili G. C. , Joel O. F.
Published: July 2015

Drill cuttings generally are bye products of drilling activities and represent pieces of components that are returned to the surface with the drilling fluid. Drill cuttings from Water Based Muds (WBMs) have been shown to pose little threat especially to the deep offshore environment, while those from Oil Based Muds (OBMs) have been widely prohibited by legislations because of their damaging effect on the environment, hence the recent requirement of zero discharge in onshore and swamp (including near offshore locations) in Nigeria. Presently, in Nigeria, there are three approved cuttings handling methods namely, Cuttings Re-injection (CRI), Thermal Desorption (TDU) and Offshore Disposal. Unfortunately, all of these methods have serious challenges. CRI and TDU treatments for instance, require large volumes of drilling waste and high capital for effective implementation as well as result in high level pollutant residues. Besides, many biological processes on the other hand, require longer treatment periods. To address these gaps, a biochemical treatment method involving the use of microbes in addition to chemical enhancers to degrade hydrocarbon-contaminated wastes into nontoxic residues is appears to be a preferred option. Biochemical treatment has been found to be cost-effective, environmental friendly and very efficient in the treatment of soil contaminated with drill cuttings.
Technical Data Tracking And Cataloguing Improves Asset Performance In Shell Nigeria
Authors: Kingsley Iheajemu , Arnold Obomanu , Erasmus Nnanna , Yvonne Jegede
Published: July 2015

In the Oil and Gas Industry, the availability and reliability of technical data is critical to effective decision making. As we often remind ourselves, most of what we know about our assets is only as good as the information available to us. Unfortunately, the reality is that unreasonable time is spent searching, gathering and many times, reworking available data before use. This has made technical data management one of the biggest challenges we face in our industry.

Data/Information Management provides a systematic approach to collecting, processing and distributing data in order to provide the integrated asset team of geoscientists and engineers, ready access to critical information throughout the life cycle of a field. Technical data tracking and cataloguing is to a large extent one of the strategic approaches to effective data management.

Reliable and sustainable data management must be hinged on a number of strategies some of which are: Tracking and cataloguing critical data.Establishing standard procedures and plans for managing dataEmbedding data analysts within Asset teams to manage data-specific activities.

When properly done, Data Management adds value through reduced cycle times and increased productivity and this is evident in several Shell Nigeria assets where Key Performance Indicators (KPIs) related to Data management have shown significant improvements. In addition, a survey of 247 participants across Shell Nigeria indicates that Engineers spent 18% of their time on data search, gathering, validation and re-work today, when compared to 55% five years ago.

This paper therefore highlights the processes and benefits of tracking and cataloguing of critical data to its final provision at the fingertips of Engineers and Geoscientists.
LPG Hydrate Formation and Prevention using Ethanol and Methanol
Authors: Olabisi Odutola Toyin , Sunday Ikiensikimama Sunday , Appah Dulu
Published: July 2015

Liquefied Petroleum Gas (LPG) is one of the alternate sources of energy because of its availability and high heating value. As the interest in LPG production in Nigeria and other developing countries increases, it is imperative to study some of the flow assurance issues associated with LPG. Due to the presence of moisture in commercial LPG, hydrates can form during LPG production, transportation and storage. Hence, it is important to predict hydrate forming conditions of LPG and propose a prevention plan if the LPG production, transportation or storage system falls in the hydrate formation zone. This paper examines the mechanism of hydrate formation in LPG and how LPG hydrates can be inhibited using methanol and ethanol. The inhibitor effectiveness was evaluated by the degree of temperature depression effected by equal amounts of these inhibitors. It was discovered that Methanol performed better than Ethanol when 20wt% of methanol and 20wt% of ethanol respectively were used in inhibiting hydrates formed in LPG. The effect of dehydration on LPG hydrate formation was also examined by varying the water content of the LPG from 7wt% water to 2.5wt% water. This simple approach to hydrate inhibition will enable the Engineer reduce the risk of hydrate formation during LPG production, transportation and storage.
Optimizing the Sourcing of Natural Gas From Intercalated Fields for Accelerated and Sustainable Low-Cost Natural Gas Supply: A Case Study of the Central Niger Delta Gas Cluster
Authors: Ogwo O. U. , Agha G. U.
Published: July 2015

This work investigates the strategies by which natural gas can be harnessed from intercalated and/or marginal fields in a given resource base and made available to end-users at the barest cost, and at the shortest possible time, ensuring equitable resource utilization. The study examines the operation of the area-franchise strategy as it concerns meeting up the accelerating energy sufficiency demand of the economy while ensuring timely extermination of gas flares; and determines the economics of the supply of dry gas to the power sector from Associated Gas (AG) and/or Non-associated Gas (NAG) wells at the regulated gas price. The work establishes the threshold feed gas volume and cost ratios for the Central Processing Facilities (CPF) and the Mini Processing Facilities (MPFs) that will enable the production of sufficient dry gas at good return on investment (ROI) under a given regulated gas price. Sample field data is used to assess the proposed strategy. It is intended that this work would guide the Government in the formulation of policies that would engender sustainable and implementable regulations on gas distribution and pricing.
Nigeria Gas to Power Value Chain Systems Economic Evaluation and Modeling
Authors: Onwuka Emmanuel I. , Iledare Omowumi
Published: July 2015

Presidential report on the Power Sector Reform 2010 as well as Gas Master Plan (GMP, 2008) vested much commitment to the gas sector towards electricity value chain viability. The result so far has been marginal. The primary challenge lays perhaps, in the impractical gas commitment contracts between the power and gas companies. Other challenges include unfavorable domestic gas pricing mechanism relative to export parity pricing; there is also the uncertainty in the security of supply lines by virtue of vandalism.

Guided by the domestic supply obligation enshrined in the GMP, this paper develops an integrated economic model that evaluates both sides of the gas to power contract. The estimated gas volume required per period is determined to facilitate the decision making process in the Nigerian power sector. A total base case data of electricity demand as established by Presidential pronouncement are imposed as reference inputs into a simple gas conversion model to develop annual gas supply equivalent for a base Take or Pay (TOP) contract life of 25 years. The developed supply profile is applied to the gas pricing model, keeping in perspective, the price transition from opportunity cost pricing in terms of netback gas export price or the export parity price (EPP).

The estimated discounted cash flow model results in terms of economic metric measures (NPV & IRR) and systems performance indicator (HGT & DHGT) show fiscal impact on profitability of gas investment. The validated model indicates that a GDP growth of 7% will require at least 3176 MW annual capacity addition and about 100 Bscf annual cumulative gas input in the next 25 years, given base boiler efficiency of about 83%. As expected, taking gas price from the stipulated 1.8 to 3.35 $/MSCF brings about proportionate increase in the NPV. It also reduces the payback period. Assigning triangular and normal distributions to gas price and turbine performance values respectively, gave the stochastic P90 NPV of between 513 and 1,925 Million USD.
An Assessment of the Role of Supplier Prequalification Audit in the Implementation, Enforcement and Stabilization of Business Regulations on Nigerian Oil Services Companies
Authors: Tubosun Fagbe
Published: July 2015

The strategic importance of compliance with National Business Laws, Regulations and standards in managing the ethical and corporate governance standards of Nigerian companies can no longer be ignored in a globalized business environment. Preparation for business, capability and capacity may be adjudged from level of the companies' compliance with National Laws. Regulations and standards were promulgated to be obeyed by suppliers and buyers as law abiding corporate entities. Non-conformity to business legal requirement may attract sanctions, loss of patronage and income, litigation, corporate image and possibly removal from national companies' register if critical. This paper examines the roles of Nigerian Oil and Gas sector's Joint Prequalification scheme on Oil and Gas service companies' adherence on the implementation, enforcement and sustenance of Nigerian Laws. The study covers about three hundred Nigerian companies in three geographical zones of South-West, South-South and North Central comprising of Lagos, Ondo, Ogun, Oyo, Delta, Rivers, Akwa-Ibom, Cross River, Edo and Abuja. Moreover critical review of several Nigerian Laws, businesses legal requirement, entrepreneur legal awareness level, Regulatory agencies' enforcement strategies and capacities, business growth and continuity as well as its consequences. The study was restricted to the compliance of Nigerian companies with National Laws before and after prequalification assessment exercise based on practical field experience between March 2010 and 31st December 2014. The paper wraps up with summaries of findings, strategic solutions recommendation and conclusion on how Nigerian companies and Regulation Agencies may boost the national economy and optimally promote business activities in a legal conscious and friendly environment through third party business evaluation scheme.
Laboratory Investigation of the Effects of Monovalent and Divalent Salts on Gum Arabic Solutions
Authors: Onaiwu D.O. O , Olafuyi O.A. A , Ogbonna J.
Published: July 2015

In field application, many factors result in the degradation and deterioration of polymer solutions during a polymer flooding project. One of these is the presence of salts which reduces the viscosity of polymer solutions. The degradation of a polymer solution by the ionic salts present in the reservoir environment varies from one polymer solution to another. This depends on the chemical and physical properties of the polymer involved and on the type of salt present in the reservoir. Therefore, a good knowledge of how the polymer solution behaves in the presence of different salts will result in a more efficient polymer flooding projects, which will invariably lead to a better oil recovery.

Gum Arabic solutions containing different salts which are commonly found in reservoirs with high salinity were prepared and viscosity tests were carried out to determine how the viscosities of these solutions varied with the concentrations of the salts. The experiments were performed specifically, on mono and divalent cations solutions.