bluuebunny/crossref_metadata_2025 huggingface dataset:
¿Cómo influyen las actividades culturales en la felicidad? Investigando la relación entre el bienestar auto-declarado y el ocio
Authors: Ateca-Amestoy Victoria , Gerstenblüth Mariana , Mussio Irene , Rossi Máximo
Published: January 2020

El ocio es una condición humana relacionada con el uso discrecional del tiempo de una manera gratificante, lo que contribuye al bienestar individual. Las personas deciden participar en las actividades culturales para disfrutar de experiencias agradables. Estas pueden explicarse al tener en cuenta el tipo de acceso: asistencia en vivo, consumo en el hogar y por la práctica de la comunidad. Se encontró un efecto positivo de las actividades culturales sobre los niveles de felicidad, efecto que es mayor al asistir al cine y menor al ver televisión.
Rendimientos decrecientes de la escolaridad en México
Authors: Caamal Olvera Cinthya G.
Published: January 2020

Se estudia la relación entre el crecimiento de una fuerza laboral con mayor nivel educativo y la remuneración que obtiene en el mercado laboral en México. Se presentan coeficientes robustos de los rendimientos de la escolaridad; los sesgos de la habilidad y selectividad se subsanan al aplicar métodos paramétricos, semi-paramétricos y semi-no paramétricos. La estrategia empírica permite comparar los rendimientos de la escolaridad entre cuantiles para analizar la desigualdad en la distribución condicionada del salario a lo largo del tiempo. Los datos revelan una tendencia decreciente en el rendimiento derivado de la escolaridad al paso del tiempo. Los resultados indican que la desigualdad entre el cuantil más alto y el más bajo también se ha reducido.
Algunos determinantes de la propensión a la innovación de productos en México: el efecto del gasto en I&D y los spillovers de conocimientos
Authors: Méndez Delgado Alba Verónica
Published: January 2020

Se estima la intensidad del gasto en I&D y su relación con la propensión a innovar de las empresas manufactureras en México. Asimismo, se analiza el efecto directo de los spillovers de conocimientos sobre las innovaciones. Se encontró que los convenios con instituciones académicas y el financiamiento público afectan positivamente el gasto en I&D, y este aumenta la propensión a innovar. Los spillovers son relevantes y afectan positivamente a las innovaciones, los resultados muestran que si se excluyen los spillovers del análisis se genera una sobreestimación del efecto del gasto en I&D en las innovaciones.
Is formal employment sector hereditary? Determinants of formal/informal sector choice for Mexican male workers
Authors: García-Andrés Adelaido , Aguayo-Téllez Ernesto , Martínez Jose N.
Published: January 2020

Understanding the relationship between parents’ and sons’ formal employment is essential for promoting social mobility in Mexico. Using the 2011 Survey of Social Mobility in Mexico (EMOVI), this paper contributes to the literature by addressing the intergenerational mobility of employment. Findings show a strong connection between intergenerational employment choices and suggest a positive selection for workers. Individuals with parents who worked in the formal sector are more likely to be enrolled in formal work and vice versa. Also, after controlling for parent’s employment sector, schooling remains as a significant vehicle to transit to the formal sector.
The relationship of emotional labor, emotional exhaustion, turnover intention and customer orientation
Authors: Park ChoonShin , Chang JaeYoon
Published: January 2020

The purpose of this study aimed to investigate the relationships among emotional regulation stratrgies, emotional exhaustion, turnover intention and customer orientation, using data from 340 female home- study teachers through structural equation model(SEM). Service workers tends to perform surface or deep acting as emotional regulation strategy during interaction with their customers. Thus, surface and deep acting may affect differently on emotional exhaustion, turnover intention and customer orientation. The results were as follows; First, surface acting was positively related to emotional exhaustion while deep acting was negatively related. Second, emotional exhaustion influenced positively on turnover intention, and negatively on customer orientation. Third, emotional exhaustion fully mediated the relationship between surface acting and turnover intention and customer orientation. It also fully mediated the relationship between deep acting and turnover intention while partially mediated the relationship between deep acting and customer orientation. Finally, the moderating effects of social support on the relationship between emotional exhaustion and turnover intention were examined. Contrary to our expectation, the moderating effects of supervisor and peer group support showed opposite buffering effect on the relationship between emotional exhaustion and turnover intention.
ISLAM NUSANTARA: PREJUDICE AND SOCIAL CONFLICT
Authors: Fahmi Reza , Aswirna Prima
Published: January 2020

This research is based on the fact that there are religious leaders and some people who oppose the idea of Islam Nusantara. When the religious figure represented a formal legal institution (MUI), it had a significant influence on the views of the people of Padang. Therefore, the polemic of Islam Nusantara gives its own style about the existence of Islam Nusantara in the land of Minang. Further research objectives: (1) Describe the prejudices of community leaders about Islam Nusantara. (2) Describe the picture of people's prejudices about Islam Nusantara. (3) Connecting the prejudices of religious leaders and the community and its relation to the social conflict of the people of Padang City. The study uses qualitative approaches and quantitative mixing methods (mixed method). The population in this study were 32 religious leaders and 168 community members. Data collection techniques using; observation, interview and psychological scale. The sampling technique is random sampling technique. Data analysis techniques using Pearson correlation (Pearson correlation). The results of this study found that generally the negative prejudices of religious leaders about Islam Nusantara were high. While social conflict in the midst of society is classified as low. Whereas the correlation aspect shows that there is no relationship between community’s prejudices about Islam Nusantara and social conflict in the midst of society.
The Mathematical Constant of Bound Space at Value 8 And -1 Constant
Authors: Cameron Vinoo
Published: January 2020

This paper is to validate by perfect mathematics / geometry the rationale behind the papers of this author published by the journal “Math Lab” and Journal of “Advances in Physics (JAP)” as referenced below. This explanatory paper is complimentary to the published papers. The square (2:2) and a rectangle (1:3) of the same value 8 by length, represents the maximal infinite and the least finite value enclosed by the same value 8 , and that the difference by area is a constant whole number -1 in all of mathematics and physics ( 2*2-1*3=1).
Site Specific Calibration Curve And Its Implication in The Treatment Planning of Head And Neck Cancer.
Authors: Srivastava Roopam , Gaur Shiva , Sharma Pramod , Sharma Manoj , Manjhi Jayanand , Das Maria , Chauhan Dr Deepika , Sehgal Dr Neha
Published: January 2020

Purpose: In this study, we created  site specific Hounsfield Unit (HU) and Relative electron density(RED) calibration curves for computed tomography(CT) and cone beam computed tomography (CBCT) for head and neck radiotherapy dose calculation and compared them with standard calibration curves.

Methods:

The calibration curves between HU and RED were generated using RANDO phantom for CT and CBCT and fed in the treatment planning system for dose calculation for head and neck patients.The treatment plans for 10 head and neck cancer patients were calculated using the standard calibration curves generated with CATPHAN and head and neck calibration curves generated with RANDO phantom for both CT and CBCT. Dose accuracy of head and neck calibration curves(H/N CC) were compared to the standard calibration curves (SCC) using dose volume metrics and 3D gamma analysis.

Results: The results show that slightly better dosimetric agreement from the SCC can be obtained when using this H/N CC.

Conclusions: A site specific calibration curves have been proposed and tested for the head-and-neck patients and the results explain the dosimetric benefits.
VEB APLIKACIJA BAZE RETKIH BOLESTI NA SRPSKOM JEZIKU
Authors: Tešanović Ivana
Published: January 2020

Predmet ovog rada jeste implemen­tacija web aplikacije koji omogućava pristup informaci­jama o retkim bolestima na srpskom jeziku, kao i imple­mentacija alata koji ubrzavaju i olakšavaju proces pre­vođenja. Rad je podeljen na više poglavlja, počevši od istorije u medicini, preko trenutnog stanja u svetu po pitanju retkih bolesti do opisa krajnjeg rešenja i tehnologija kojima se služilo da se dođe do istog.
Bidibidobidiboo
Authors: Portinari Stefania
Published: January 2020

Maurizio Cattelan's poetics is filled with wrong and irreverent details. It can be a pigeon inside a room at Venice Biennale or a chasm in the floor of a museum, it is the inscription "Hollywood" in the wrong place, it is a strange door in an alley of Chelsea in New York, an ambiguous word in a sign or a stolen expression in an interview. Details of stories and interiors then become devices to activate interpretative practices, relational aesthetics and postproductions, to create misunderstandings because – as the artist claims – "truth is only the moment when you claim something like yours".
¿Santuarios educativos en México? Proyectos y propuestas ante la criminalización de jóvenes dreamers, retornados y deportados
Authors: Giorguili Saucedo Silvia , Garrido de la Calleja Carlos Alberto , Anderson Jill , Délano Alonso Alexandra , Ángel Lara Hiram Abel , Cabrera Ángelo , Suárez Daniela , Ortega Arámburo Adriana , Fernández Hall María Cristina , Amaro Gutiérrez Víctor Hugo , Aguilar Zepeda Rodrigo , Ortiz Domínguez Lucía Cristina , Vázquez Vázquez José Dionisio , Varela Huerta Amarela
Published: January 2020

Hace justamente diez años que se dio el cambió de tendencia en la migración entre México y Estados Unidos. Coincidente con la peor crisis económica en varias décadas y con el ambiente de persecución e incremento de las deportaciones durante la presidencia de Obama, los expertos en migración teníamos suficientes señales del cambio que se avecinaba en los patrones migratorios. Aún así, el increíble crecimiento de la migración hacia nuestro vecino del norte y el pico de más de 600 mil mexicanos que dejaron el país nada más en el año 2005 nos hacían pensar que la migración era imparable y que esta pérdida de población —porque a final de cuentas es una pérdida— duraría varios años, lustros e inclusive décadas más.
Escenarios de la práctica docente en el siglo XXI: sistematización e innovación
Authors: Ruiz Libreros Martha Elba , Peña Hernández María de los Ángeles , Arellanez Hernández Jorge Luis , Arias Vázquez Juan Carlos , Arieta Pensado Federico Rafael , Cabrera Jiménez Rosa María , Campirán Salazar Ariel F , Carrillo Puertos Liliane , Castillo Ortega Sara Esther , Cortés Flores Erika , del Callejo Canal Diana Donají , Delfín Linaldi Ana Luz , Dorantes Carrión Jeysira Jacqueline , García Zamora María Esther , González Hernández Amador Jesús , Hernández Maldonado María Luisa , Hernández Marín Gloria de Jesús , Hernández Martínez Sara Zurisadai , Hernández Suárez Bertha María Rocío , Maldonado Vela Uzziel , Martínez Hernández María de Jesús , Molares Flores Cecilia , Morales Martínez Martha Edith , Soto Pérez Betsy , Tercero Velasco Angélica Victoria , Yon Guzmán Silvia Estela
Published: January 2020

Este libro promueve la divulgación académica colaborativa gracias a los autores que se unen al reto de investigar, escribir y comunicar sus hallazgos. Las aportaciones aquí vertidas son puntos de articulación sobre la práctica docente, los cuales se circunscriben a tres ejes temáticos: 1. Innovación y sistematización en la práctica docente, muestra experiencias que analizan dicha práctica desde la mirada de los actores clave del proceso de formación del ser humano. 2. Modelos y pautas didácticas en el tránsito hacia la sustentabilidad, abarca los procesos de planeación, diseño, intervención y evaluación para educar en la sustentabilidad. 3. Modelos y pautas teórico-prácticas para la aplicación del pensamiento crítico en la solución de problemas, identifica la relación específica de modelos de razonamiento con habilidades analíticas o crítico-creativas, identificables en la prevención, intervención y modificación de situaciones-problema disciplinares o transdisciplinares.
Enhance the Gas Productivity for Shale Gas Reservoirs Using Thermochemical Treatment
Authors: Hassan Amjed , Mahmoud Mohamed , Al-Majed Abdulaziz , Al-Nakhli Ayman
Published: January 2020

In shale reservoirs, the gas productivity is severely reduced due to the formation tightness. The extreme low permeability of shale formations can result in reducing the gas flow into the borehole, and consequently the gas production can be significantly reduced. This paper presents an effective technique for enhancing the gas productivity for shale gas reservoirs using thermochemical fluids. The used chemicals can generate heat and pressure in-situ and improve the flow condition by creating micro- factures in the shale rocks. Experimental measurements and analytical calculations were carried out to investigate the enhancement in gas productivity for shale samples due to the injection of thermochemical fluids.

Coreflooding experiments and rate transient analysis (RTA) were conducted as well as nuclear magnetic resonance (NMR) measurements. Tight core samples from eagle ford formation were used in the flooding experiments. The improvement in gas productivity due to thermochemical injection was evaluated using rate transient analysis. The profiles of pressure-drop and gas flow-rate were used to estimate the gas productivity before and after the chemical treatment. NMR measurements were used to study the changes in the pore network due to thermochemical stimulation. The T2 signal distribution was obtained before and after the chemical injection. Furthermore, analytical calculations were performed to estimate the enhancement in gas productivity due to the thermochemical treatment. The increase in absolute open flow (AOF) and the productivity index (PI) due to the chemical treatment were determined.

Results showed that treating shale rocks with thermochemical fluids can enhance the gas productivity by 62% and reduce the capillary pressure by more than 45%. Also, the absolute open flow can be increased four times due to the thermochemical injection into shale reservoirs. The generated heat and pressure due to thermochemical treatment can induce permanent alterations in the shale matrix and then improve the hydrocarbon flow for long term. NMR measurements, before and after the treatment, confirm the creation of tiny fractures during the chemical injection. The novelty of this work is that an effective treatment is presented to enhance the gas productivity for shale formations. Ultimately, this study will be very useful for treating the shale reservoirs with thermochemical fluids to improve the gas productivity, and consequently enhance the total gas production from shale reservoirs.
Digitizing Chemical Data for Real Time Flow Assurance
Authors: Lovell John , Kulbrandstad Omar , Madem Sai , Meza Daniel , Babakhani Aydin
Published: January 2020

By minitiaturzing and ruggedizing laboratory equipment historically used for geochemical applications, it is now possible to digitize chemical attributes of molecules as they flow through the wellhead. Specifically, the number of unpaired electrons in outer-orbitals can be tracked in real-time as well as the hyperfine interaction of those electrons with spin-properties of nuclei within their associated molecules. This sounds very esoteric but in fact has a direct relationship with traditional flow assurance problems that have previously been very difficult to manage. For example, considering those electrons which correspond to free radicals within asphaltene molecules, then, in the presence of a very strong magnetic field, they will resonate at a specific microwave frequency. By exposing the well fluid to exactly that combination of magnetic and RF fields, the amplitude of the resonance is proportional to the number of asphaltene molecules. Unlike some optical and infra-red techniques, this gives a measurement of the total amount of asphaltene flowing, not just a measurement of the non-dissolved component. This measurement can be made continuously, so that gives a time-series analysis of the percentage of asphaltene that is flowing in the oil. AI-based software has also been written to extract further information from the resonance data, such as the water-cut and gas-oil ratio. Operators can use this combined information to optimize their flow-assurance strategies, for example, to give immediate feedback on the result of changing an inhibitor or dispersant.

An initial version of the tool was deployed for a field-test in Abu Dhabi in Q4, 2017. Data from the system was transmitted via the cloud to asphaltene experts remotely monitoring the data. The resolution of the device proved better than expected, which allowed the system to give a previously unseen dynamic view of asphaltene chemistry. One surprise was that the asphaltene percentage might vary significantly over the course of a few hours, even when the surface pressure and flow-rates stayed the same. Troublesome wells had the highest standard deviation which gives a new key performance indicator (KPI) for flow assurance risk. Another unexpected result was that surface asphaltene levels would drop for a few days after a xylene soak, before slowly returning back to their baseline. This indicates that a freshly-cleaned tubular is more attractive for asphaltene deposition, and stays that way until a sufficiently thick asphaltene coating has accumulated.

Based on these results, additional hardware has been delivered to Abu Dhabi to begin a long-term pilot study on the use of electron resonance data for asphaltene management. Moreover, the device opens up to the oilfield traditional laboratory uses of electron resonance such as identification of kerogen maturity and geochemical rock typing.
Researching and Testing on Casing Ball Seat for Multistage Fracturing in Horizontal Wells
Authors: Liu Zhongneng , Wang Zhiguo , Ren Guofu , Guo Siwen , Gui Jie , Ren Yong , Xue Xiaowei , Zhao Minqi , Feng Changqing
Published: January 2020

Plugs have been widely used for staged fracturing in horizontal wells. But in wells with long lateral or low reservoir pressure, plug milling are far more complex due to debris accumulation and fluid loss.

This study proposed a new multistage fracturing solution for horizontal wells using one kind of ball seat. Researchers have designed mechanical model of the seat. Metal material with great flexibility has been selected out and processed into seats according to the model. The key tools such as elastic seat, large-diameter soluble ball and the matching tools such as cylinder and launching tool were developed. The results of indoor tests and large-scale simulation tests of real parameters have shown that the seat has the capability of repeated rebounding and the capacity of pressure bearing and packing reaches 70MPa. Field tests of 12 horizontal wells, containing totally 115 stages, have been carried out and achieved the technological goals of infinitely large-scale staged fracturing, no milling, and nearly full-bore access. The fracturing cycle has been shortened by more than 30% and the operation cost of single well has been reduced by more than 15%.
The Study of Low Cost & Effective Volume Fracturing Technology for Wells in Normal Pressure Shale Gas Play in China
Authors: Bian Xiaobing , Ding Shidong , Jiang Tingxue , Xiao Bo , Su Yuan , Li Shuangming , Wei Ran , Wang Haitao , Du Tao
Published: January 2020

Relatively, the gas production is low for fractured horizontal wells in normal pressure shale gas plays with a quick production decrease, resulting in larger difficulty for commercial breakthrough and economic development. Accordingly fracturing technology is under study urgently.

On condition that production increased and engineering cost decreased, together with feasible and practical fracturing technology, the production potential is studied to put forward several hydraulic fracturing treatment. Firstly, cluster spacing is decreased, while increasing cluster number per stage, thus, there are more total clusters for one well with less stages, the influence of induced stress could be strengthened especially using plane perforation. Secondly, using high viscosity gel as pre fluid or flushing fluid among injecting period, to extend fracture through layers vertically. Thirdly, by use of ultra-low density small mesh proppant, increasing net pressure sharply by plugging the front of fracture. Fourthly, increasing ratio of lower viscosity slick water, small mesh proppant and higher viscosity gel, to improve hydraulic fracturing pumping pattern and technological parameter by varying viscosity, varying displacement, varying mesh proppant, so multiscale fracture propagate and propped with corresponding size of proppant. Fifthly, deminishing lower effective and non-effective clusters through studying geological and engineering sweetness.

Aiming at production increased and engineering cost decreased, the production potential is studied to put forward several hydraulic fracturing treatment, which is feasible and practical. Good result was observed in pilot application of D well and L well, providing theoretical support for developing effectively and economically in similar shale gas play.
Well Log Interpretation Using Deep Learning Neural Networks
Authors: Gupta Aarushi , Soumya Utkarsh
Published: January 2020

As artificial intelligence continues to revolutionize the industries around with innovations that make work easy and fast, its’ use in the Oil and Gas Industry has been quite limited. With the technology available to us, artificial intelligence ought to revolutionize the Oil and Gas Industry, mainly by time-saving and increasing the ease of operation. This study uses deep learning to predict the lithology of the formations encountered with the use of open-hole log data. It also works to calculate the porosity of the hydrocarbon bearing formation using the density and neutron values. The trained program analyses and assimilates the log values to indicate the lithology, reducing the time of the operation during the exploration stage. If used as a real-time indicator, the program ought to ease the drilling operation. With drilling being one of the costliest operations, any ease in the process that saved time would be a boon to the Industry. The paper gives a summary of the technique used and discusses the work that could further strengthen the operation at hand.
Multiphase Flow Simulation to Estimate Erosion/Corrosion Potential in Gas Sweetening Process Piping
Authors: Oshinowo Lanre , Said Faisal , Bokhedaim Yahya , Suwailem Khalid , Paul Mishar , Methn Abdulrahman
Published: January 2020

The magnitude of the phase velocities and turbulence, and the stability of protective sulfide scale affects the degree of erosion-corrosion in amine lines. Avoidance of high velocities, turbulence and stagnant regions can reduce the impact of erosion-corrosion in amine plant piping networks. Separated or stratified flow regimes influence the distribution and efficient spreading of corrosion inhibitor over pipe circumference. A combined process simulation and Computational Fluid Dynamics (CFD) modeling study was conducted to predict the multiphase flow regimes and phase velocities in the rich amine pipe segment between the rich/lean exchanger and the stripper column inlet. The objectives of the study were to determine the multiphase flow regimes in the rich amine line to stripper, and identify regions of locally high velocity relative to the mean velocity of the rich amine. A transient multiphase CFD model of the rich amine pipe segment used inputs from process simulation for different gas/liquid ratios ranging from low gas to high gas to predict and visualize the two-phase flow patterns and velocity distributions. Localized high liquid velocities and wall shear stresses were predicted in the pipe segments corresponding to observed corrosion. A key finding is that the multiphase flow regimes in piping of interest are invariant of the operating gas volume fraction ranging from 0.01 to 0.80. A set of recommendations were developed to mitigate the adverse flow regimes and corrosion potential to further enhance the acid gas handling plant operation and support the inspection unit in mitigating a corrosion environment.
The Application of a Fiberglass Liner in Well Tubing as Cost Effective Material Option in High Velocity Production Wells
Authors: Repetto Carmen , Gorini Simone , Nutricato Giacomo Andrea , Torri Lucia , Cavassi Paolo , Zucchetto Maria Ornella , Guglielmo Carmelo , Piccolo Aureliano , McIntosh Neil , Balistrieri Roberto
Published: January 2020

This paper describes Eni's experience in the application of a Fibreglass liner used as a corrosion barrier in well tubing and the tests performed in high erosion conditions.

Liner is made of a Glassfibre Reinforced Epoxy (GRE) resin, inserted in Carbon Steel tubing used in both oil production and water injection wells.

Following many successful experiences in these applications, Eni decided to look at what additional requirements would be needed to prove GRE as an alternative material to high grade Corrosion Resistant Alloys (CRA's) for installation in high velocity gas wells.

The GRE liner was selected as cost effective alternative to high alloyed materials starting from 2005, where GRE was successful in reducing onshore workover costs and extending the life of Carbon Steel tubing in oil producer wells with high CO2 and water cut, to the more recent installation offshore Norway in Water Injection wells where due to high corrosiveness of the injection fluid.

The paper will summarise the testing and the appalication range of GRE in corrosive CO2 and H2S environments and also, through collaboration with Milan Polytechnic, the high flow direct impact erosional testing, utilising a continuous flow loop and nozzle directed solids impingement testing system. Various impinging angles, times and velocities were used during the testing. The results showed GRE to have a good resistance to the solid particles erosion in comparison to the similar tests carried out on Inconel Nickel Alloy material and confirms the potential use of GRE as a corrosion resistance material when combined with Carbon Steel tubulars and alternative to high CRA materials in producer wells.

Together with economic evaluations, the paper presents the characteristics of the GRE technology, the acceptable range of field conditions and will highlight feedback for the sites it has been applied.
Greenfields Production Facilities Optimization Using a Transient Multiphase Flow Simulator
Authors: Al-Qasim Abdulaziz , Al-Mudairis Fahad , Alsubhi Mutaz
Published: January 2020

This paper discusses a method for optimizing production facilities design for onshore/offshore wells during new field development. Optimizing the development of new oil and gas fields necessitates the use of accurate predication techniques to minimize uncertainties associated with day-to-day operational challenges related to wells, pipelines and surface facilities. It involves the use of a transient multiphase flow simulator (TMFS) for designing new oil and gas production systems to determine the feasibility of its economic development.

A synthetic offshore oil field that covers a wide range of subsurface and surface facility data is considered in this paper. 32 wells and two reservoirs are considered to evaluate the effect of varying sizes of tubing, wellhead choke, flowline, riser, and transport line. A detailed investigation of the scenario of emergency shutdowns to study its effect on the system is performed using TMFS. Other scenarios are also evaluated such as startup, depressurization, pigging, wax deposition, and hydrate formation.

This paper provides a method to minimize the cost by selecting the optimum pipelines sizes and diameters, and investigating the requirements of insulation, risk of pipeline corrosions and other related flow assurance parameters. Different facility design scenarios are considered using TMFS tool to achieve operational flexibility and eliminate associated risks. Pressure and temperature conditions are evaluated under several parametric scenarios to determine the best dimensions of the production system. This paper will also provide insight into factors affecting the flow assurance of oil and gas reservoirs.
Acid Fracture Conductivity Testing on the Tight Carbonate Ratawi Limestone in the Partitioned Zone
Authors: Naik Sarvesh , Dean Mark , McDuff Darren , Ranson Andrew , Jin Xiao , Zhu Ding , Hill Alfred Dan
Published: January 2020

Saudi Arabian Chevron (SAC) partnered with the Texas A&M University Petroleum Engineering Department and Reservoir Productivity Geomechanics Team of Chevron's Energy Technology Center (ETC) to perform acid fracturing conductivity tests on the Ratawi Limestone core samples. These tests were also performed on an analog limestone from an onshore USA field and Indiana Limestone samples for comparison with the results from the Ratawi Limestone samples. This paper shows the results of the acid fracture conductivity tests using various acid treatment systems on three different limestone formations and compares the acid etching and conductivity responses between homogeneous and heterogeneous mineralogy.

The success of acid fracturing treatment depends on the creation and sustainability of fracture conductivity under reservoir conditions. The fracture conductivity depends on the reservoir rock & acid reactivity, acid-etched pattern, closure stress on the fracture face and the pore pressure depletion.

Laboratory testing shows that acid fracturing is a viable option for large-scale development of the Ratawi Limestone. Its heterogeneous mineralogy plays an important role for sustaining the fracture conductivity after acid injection. Composed primarily of calcite and dolomite, limestone dissolves positively in acid. However, the insoluble minerals, such as the clay streaks with higher mechanical properties, acted as pillars to partially prop the fractures open as closure stress was applied. Essentially, the heterogeneous mineralogy of this formation assists with sustaining fracture conductivity as the reservoir pressure depletes.
New Environmentally Friendly Solution for Iron Scale Removal
Authors: Gamal Hany , Abdelgawad Khaled , Elkatatny Salaheldin
Published: January 2020

Iron sulfide scale is considered a big issue in the oil and gas industry and a very common problem in daily operation bases. The iron scale severely affects the production rates and field operation, as the iron scale precipitation on the well completion tools or the pipelines` inner surfaces will decrease the diameter size and cause flow restriction. Failure of the downhole completions tools will decrease the well production and it might require workover operations to cure the problem. Such workover operations add an extra cost. In addition, the iron scale is a big problem for the petroleum reservoirs as it changes the rock wettability from water-wet to oil-wet. Many studies and researches were performed to find an economical and efficient removal for the iron sulfide scale. The main objective of this study is to find a new environmentally chemical solution to be used for iron sulfide scale removal. Additionally, to study the new fluid performance in terms of solubility for an iron scale (field sample), corrosion effect, and biodegradability for environmentally safe use.

Lab solubility tests had been done at different times and concentrations to get the optimum time and concentration that provides the optimum iron scale solubility rate. Corrosion tests were performed to determine the corrosion rates for the new chemical and the results were compared with other commercial chemicals for iron scale removal.

The results from the study showed excellent performance for the scale solubility and for the corrosion rates. The iron scale solubility showed 82 % after 6 hours at 125°C for the static condition. In addition, the solubility rates ranged from 77% after 2 hours to 81% after 24 hours along the 24 hours of different time steps. The corrosion rate is 0.04 lb/ft2 which is considered a small rate compared to other used commercial fluids. The research outcomes provide an efficient chemical for iron scale removal that is environmentally safe to be used in the oil and gas fields. The new environmentally friendly acid system NEFAS provides very good performance for iron scale removal, with a lower cost than commercial chemicals. Furthermore, the new system is a biodegradable and environmentally safe system.
Designing Networks with and for Petrophysicists: Automated Grain Size Prediction from Microresistivity Logs
Authors: Basier Florian , McLean Kim , Pelling Richard
Published: January 2020

Image logs such as Microresistivity give the interpreter an indication of bedding patterns and depositional environments. This allows him, after correlation with an analysis of selected curve shapes (SP, GR) to interpret the grain size along the well. Both image analysis (from image logs) and data aggregation are areas where Deep Neural Networks have proven efficient, but their accuracy in the field of grain size prediction is still limited, hence not useful yet for an interpreter. Since relevant and complete log data is usually only available on small intervals, networks are overly trained on hand-picked well sections, while ultimately predicting a softmax-activated vector of all grain size "probabilities".

Working with data from deepwater wells off the Gulf of Mexico, we have been able to account for uncertainties and scattering in the training data to produce a set of single-tasked, multi-input, multi-output classification CNNs. Combined, these networks produced more accurate results than their multi-category counterparts, with accuracy over 87% on test wells. Using the computed metrics (recall, precision) of these single networks, a confidence curve of the overall algorithm is produced, highlighting high-confidence high-accuracy areas (85% of test wells), as well as areas where human interpretation is required.

This approach combines Machine Learning prediction and uncertainty analysis to reshape, using deterministic methods, the "black box" predictions of the Neural Network. This provides a methodology which is more accurate than conventional Machine Learning, while also being aware of its own inaccuracies and highlighting them. It uses complex network architectures and data ingestion mechanisms, designed to generate results that can be exploited by a petrophysicist in charge of log interpretation.
An Experimental Study and Finite Element Modelling of Thermochemical Fracturing in Ultra-Tight Cement Mortar Samples
Authors: Tariq Zeeshan , Mahmoud Mohamed , Abdulraheem Abdulazeez , Al-Shehri Dhafer , Al-Nakhli Ayman , Murtaza Mobeen , Mustafa Ayyaz
Published: January 2020

Current global energy demand and supply gap needs the best engineering methods to recover hydrocarbons from the unconventional hydrocarbon formations. Unconventional hydrocarbons normally present in deep formations, where the overburden stresses and formation integrity are very high. When fracturing these types of formations, the hydraulic fracturing job becomes much more challenging, and in some scenarios, pumping reached to the maximum capacity limits without generating any fracture. This reduces the operational gap to optimally placed hydraulic fractures. In the present research study, a novel thermochemical fracturing approach is presented to reduce the breakdown pressure of the high-strength formations. The hydraulic fracturing experiments presented in this study are carried out on ultra-tight cement block samples. The composition of cement blocks is synthesized in this way that it simulates the real rocks. The results showed that the newly proposed thermochemical fracturing approach reduced the breakdown pressure in ultra-tight cement from 1095 psia (reference breakdown pressure recorded from conventional hydraulic fracturing technique) to 705 psia. The post treatment experimental analysis showed that the thermochemical fracturing approach resulted in a deep and long fracture while conventional hydraulic fracturing resulted in a thin fracture. In addition to that, a Finite element analysis using ABAQUS is also presented. The main purpose of the numerical investigation is to confirm the sufficiency of the experimental data for reproducing the same breakdown pressure that included depiction of injection pressure versus time plots, failure loads and cracking patterns.
Blockchain Applications in Midstream Oil and Gas Industry
Authors: Kadry Heba
Published: January 2020

Blockchain is believed to be a foundational technology that will create foundations in the economic and financial systems in a way that will revolutionize the business models and the organizational structures. Blockchain has opened a series of possibilities for blockchain-based innovative applications that are extended to midstream Oil and Gas industry.

In the era of the digital revolution, the need for an advanced information and communication technology has become crucial in midstream oil and gas industry to be able support increased challenges of decarbonization, decentralization, digitalization, and security. Blockchain is proposed to be an integrated platform through a series of different applications, such as, metering, billing, carbon trading, security, supply chain management, and performance-based contracts. The opportunities and impacts of utilizing blockchain-based applications will be demonstrated including economic, environmental, operational and social related benefits. Blockchain is disruptive technology, however, the current applications are in early development phase. Key improvement areas have to be assessed to reach the desired levels of scalability, decentralization and security. The paper concludes that this technology has significant potential to enhance the efficiency and maximize the profit that needs further digging from both research and industry. This work provides an overview of the blockchain technology and working principles. It describes the novelty and innovation that blockchains brings to industry, especially when combined with smart contracts. Also, the paper explores blockchain potential for the midstream oil and gas industry and investigates the state-of-the-art current business cases. To the best of our knowledge, this is one of the earliest works to explore blockchain-based applications in midstream oil and gas industry.
Combining 1C & 3C Sensors: An Evolution in Passive LFS Low Frequency Seismic Exploration
Authors: Al Jadani Mohammad , Birialtcev Evgenii , Ryzhov Vasilii , Feofilov Sergey , Mokshin Evgenii
Published: January 2020

Passive low frequency seismic exploration is a technology for specifying the geological attributes of the earth's interior. Known examples of its application for tasks, for example, determining of the contour of hydrocarbon deposits (direct hydrocarbon indicator DHI) [2, 4, 8, 14, 18, 21, 23, 26, 35, 36, 37]. However, most of the results are qualitative.

In this paper, we propose a physic-mathematical method for interpreting this phenomenon, based on the recognized approaches of extracting the Green function from passive observations [27, 45, 46] and methods for solving the partial problem of full-wave inversion [16]. It is known that the correlation function of observations of a random field carries information about the Green function, which is a response to the structure of the geological setting [15]. We additional filter out Rayleigh surface waves and inclined waves using linear prediction algorithms [10].

It is assumed that the properties of the medium are known; it is necessary to determine the location of a small-thickness formation with anomalous absorption. Hydrocarbon deposits with high permeability are recognized with high absorption. Abnormal absorption at low frequencies occurs as a result of friction of the liquid phase of hydrocarbons on the skeleton of the rock during the passage of longitudinal waves [7, 10]. Contrast of anomalous absorptions can cause additional reflections (resonance).

The task is reduced to a one-dimensional partial task of the full-wave inversion, when the base model is generally known, and it is necessary to find individual deviations (oil-saturated reservoirs). A numerical simulation is performed with different possible placements of a search object. Field record spectra, after applying filtering procedures, are matched with synthetic ones. We solve this problem in the Born approximation of single scattering with regularization in the form of restrictions on the coefficients, this problem is solved by quadratic programming. The proposed method has been applied to solve problems of hydrocarbon prospecting [41].

Combining 1C (single component) sensors and 3C (three components) ones is considered as an evolution to solve problems concerning scarcity of passive LFS data due to our long-time reliance on 3C sensors only to collect such valuable data. Quantitative approaches will merge soon!
A Novel, Cost Effective and Easily Scaled Solution for On-Site Treatment of Oily Wastes
Authors: Thomas David , Bireta Paul , McVey Kevin , Segal Daniel , Hudson Matt , Sami Bu-Hulaiyem , Gabriel Sabadell
Published: January 2020

Treatment and management of oil-impacted wastes (e.g. tank bottoms, clarifier or pit sludge, oil-impacted soils) poses significant technical and financial challenges at exploration and production (E&P) facilities. Often these materials are distant from waste disposal or treatment facilities or are inaccessible to the equipment necessary for treatment. Further, the size of treatment facilities and associated costs may make treatment of these wastes unviable.

Heated Overland Thermal Treatment Pad (Hottpad), is a novel, cost-effective and easily scaled solution for oil impacted wastes at E&P sites that has been developed and field demonstrated. Hottpad consists of a metal pad with metal or dirt-bermed walls, which is then covered with oily waste material or oil-impacted soil for subsequent treatment via smouldering combustion. Since initial deployment in 2016, the technology has been further improved and refined to target two applications of interest; i) small, portable systems designed for treatment of stranded wastes and ii) centralized, bespoke scale treatment facilities. Both systems are designed for on-site treatment with conversion of wastes to materials suitable for reuse.

The current Hottpad configuration is the culmination of more than 8 years of collaborative research, technology development, refinement and improvement. Hottpad has been demonstrated to be highly effective at meeting remediation goals, is cost-effective, and is a more sustainable and lower risk alternative to the traditional means of treatment that rely on off-site transport of impacted materials.
Productivity Evaluation of Radial Multi-Branch Horizontal Well in Unconventional Gas Reservoirs Considering Permeability Variation: Model Establishment and Sensitivity Analyses
Authors: Shi Juntai , Fang Yexin , Wu Jiayi , Sun Zheng , Tang Jizhou , Li Qian , Chen Zan , Lu Jiaguo , Ke Wenqi , Jia Yanran , Wang Yabing , Lu Wenming
Published: January 2020

The low permeability of unconventional gas reservoir makes it difficult to achieve good development effect. Hydraulic fracturing technology and multi-lateral well technology are usually adopted to increase the gas production. What's more, the permeability may change dynamically during the production process because of the effective stress, gas slippage and matrix shrinkage effect.

In this paper, we first establish the productivity equation of radial multi-branch horizontal (RMBH) well in unconventional natural gas reservoirs, considering the dynamic change of permeability during the production process. Then, the productivity equation of radial horizontal well with 2 branches is compared with fractured vertical well and conventional horizontal well productivity equations proposed by former researchers. Finally, main factors influencing the productivity of unconventional natural gas RMBH well are analyzed, including well structure parameters, gas formation properties and production stage.

Results show that the productivity equation of degenerated RMBH well with 2 branches is proven to be reasonable by comparison with those of vertically fractured well and horizontal well. RMBH well shows more advantage in the formation with relatively large difference between maximum and minimum stresses, indicating that this type of well configuration may be an alternative technique for improving gas production in unconventional gas reservoirs. Sensitivity analyses demonstrate that the gas production rate of RMBH well is sensitive to branch length, branch number, build-up section horizontal distance, and stress dependence effect. The radial horizontal well with 4 branches can achieve a best development effect and economical benefit.
Delayed Oil Swell Packer for Openhole Zonal Isolation of Long Laterals Wells
Authors: Sadana Anil , Kovalchuk Anton , Cook Christopher
Published: January 2020

Swellable elastomer packers are the preferred choice for openhole zonal isolation for many applications due to their cost-effective and interventionless deployment. For drilling long laterals, customers prefer to drill in oil-based muds (OBM) because the OBM acts as a lubricant and helps deeper and faster drilling.

The swell packers are deployed in OBMs up to total depths (TD) of 36,000ft and require sufficient time to run liner to bottom, pull out of hole with running string, and run a displacement string to total depth (TD) to displace the OBM mud to a completion brine and breaker prior to the swell packer contacting the 8.5-in. open hole. Thereafter, upon exposure to produced or injected fluid, the packer must hold pressure to a wash out an openhole diameter of 9 in. > 1,000psi. Commercial oil swell packers meet the differential pressure requirements, however, their fast swell rate, especially in high-temperature applications, presents a significant challenge in getting these packers to the required depth/distance.

In this paper we report the development and testing of 11-day delay oil swell packers to compartmentalize an 8.5-in. openhole, seal a 9.25-in. washout zone, and hold a minimum differential pressure of 1000psi at 220° F. Swell delay was conducted on 20-in. × 8.15-in. OD donuts (dunk packers) on a base pipe 6.625-in. OD in oil-based mud (NAF) at 200 to 207° F. Pressure testing was performed as per API190H standard on packers (4 ft × 8.15 in. and 5.5 ft × 8.15 in.) on a 6.625-in. base pipe that was pressure tested at 225° F by applying pressure from top and bottom annulus. These packers held a steady differential pressure of 1100 to 1300 psi for 30 minutes.

This development enhances the ability to reliably compartmentalize larger open holes with potential washout sections by using a delayed swell oil packer.