bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of Alkali-Surfactant-Polymer ASP Flooding for Improving Viscous Oil Recovery From Alaskan North Slope Reservoir
Authors: Ghorpade T. S. , Patil S. L. , Dandekar A. Y. , Khataniar S. 
Published: April 2016

Abstract
Alkali-surfactant-polymer (ASP) flooding is a chemical EOR method that can be used to improve recovery of heavy oil containing organic acids by increasing sweep efficiency, and reducing interfacial tension. Typically, ASP flooding is followed by extended waterflooding. The concentration of alkali, surfactant, and polymer used in the process depends on oil type, connate water salinity, pressure and temperature of the reservoir, and injection water quality.
In this study, an ASP flood was designed to optimize the concentration of alkali, surfactant, and polymer for an Alaskan reservoir using a reservoir simulation model. Also, the effects of waterflooding and improvement with ASP flooding were evaluated and compared. Based on literature review and previously published screening criteria, the Western North Slope (WNS) 1 reservoir was selected for application of the ASP process and a simulation model for this reservoir was generated with 5-spot flood pattern. Reservoir fluid properties were modeled through regression analysis of actual field data. Simulation runs conducted for primary and waterflooding processes showed that the recovery factor increased from 3% due to primary recovery to 45% due to waterflooding at 500 psi drawdown for 60 years with a constant producing gas oil ratio (GOR). ASP flooding was conducted to increase recovery further, and optimum ASP parameters were calculated for maximum recovery. Also, effect of alkali, surfactant and polymer on recovery was observed and compared with ASP flood. If proved effective, the use of ASP chemicals for Alaskan North Slope (ANS) reservoirs to increase the recovery factor could supplement current miscible gas injection with chemical EOR. It will help to develop chemical flooding processes for heavier crude oil produced in harsh environments and create new horizons for chemical industries in Alaska.
Data Mining with Shapelets for Predicting Valve Failures in Gas Compressors
Authors: Patri Om P. , Tehrani Arash S. , Prasanna Viktor K. , Kannan Rajgopal , Panangadan Anand , Reyna Nabor 
Published: April 2016

Abstract
Gas compressor failures are frequently caused by breakdown of valves. Since production is dependent on rotating equipment, it is useful to minimize downtime caused by such valve failures, and try to predict them in advance. This is a challenging problem, which we address using Big Data analysis of the data gathered by a large number of sensors deployed on various parts of the compressor. These sensors take periodic readings (at every few minutes) of various physical properties of the compressors including motor winding temperatures, compressor vibrations, and pressure and temperature for both suction and discharge at various compression stages. We frame this problem as a multivariate time series classification task, and propose a novel machine learning approach to solve it.
Our proposed approach is based on the concept of shapelets, which are discriminative subsequences extracted from time series. This approach does not make assumptions about the nature of the dataset (crucial for real industrial datasets) and has very fast classification times. These shapelets act as a ‘signature’ capturing the characteristics and differences between sensor data related to normal valve function versus failed valve function. Shapelets are increasingly being used for univariate (single dimension data read by one sensor) time series data mining. But there have been few efforts to solve the problem of multivariate time series classification using shapelets due to the additional challenges emanating from multiple sensors in terms of the size and variety of data. Specifically, the existing approaches make the assumption that the reading of sensors are independent, which is not the case for sensor data in gas compressors as variation or anomaly in a valve affect the reading of adjacent sensors. Since all the sensors record data synchronized in time, the temporal dependencies across them need to be captured.
In this work, we propose a method, which attempts to incorporate these dependencies into the final shapelet-based classification framework. We achieve this using a heuristic of inter-leaving time series data across the sensors. This helps us reduce the multivariate time series data to a univariate format such that existing univariate shapelet extraction methods can be applied directly on the data. We evaluate our approach on real sensor data taken from gas compressors in an oil field in North America. Our results illustrate that time series approaches based on shapelet mining are valuable for fast prediction of failures from sensor data in oil and gas fields. These approaches provide key insights into the functioning of the individual sensors as well as deliver a visual aid to domain experts for further root cause analysis.
Alaskan Viscous Oil: EOR Opportunity, or Waterflood Sand Control First?
Authors: Paskvan Frank , Turak Joe , Jerauld Gary , Gould Tom , Skinner Robert , Garg Amitabh 
Published: April 2016

Abstract
A regional depletion planning and comprehensive EOR screening was completed for Alaskan viscous oil (VO) resources, which have in-place volumes exceeding 10 billion barrels (Figure 1). Developed areas are shown in dark blue. With initial production dating from 1985 and a moderate development pace, viscous oil has experienced technology waves in drilling, completion, and EOR capability. Lower viscosity portions of the reservoir have typically been developed first. To date, ~ 150 million barrels of viscous oil have been produced. Ugnu heavy oil (HO) resource footprint is shown by the red outline; areas of overlap may yield development cost savings opportunities.
This multi-year screening effort was undertaken and funded by BP to deepen understanding of extraction techniques, development options, and operability issues that need clarity prior to moving discrete development projects forward. Key viscous oil challenges are high well and facility costs, low well deliverability, and low waterflood oil recovery (less than 20%). This screening included technical evaluations and laboratory studies that led to separately funded geomechanics studies and field trials. This work addressed these main questions:
Can we improve the oil recovery factor? How far up the viscosity continuum can we progress? Can development cost be reduced to acceptable levels?
Alaska viscous oil resides in soft, friable, pressure/stress sensitive sands. A key performance issue in early- to mid-life for many waterflood patterns is catastrophic rock failure with water short-circuiting between producer and injector or producer and aquifer, called a matrix bypass event (MBE). Potential MBE mechanisms were evaluated using a coupled reservoir flow, rock mechanics, and sand transport model to predict sand failure processes and evaluate remediation and prevention options. Installing producer sand control, maintaining reservoir pressure, and moderating the interwell pressure gradient reduces sanding and MBE risks, extends waterflood pattern life, and increases oil recovery.
Heavy Oil Mobilization by Cold Solvent, Hot Solvent, and Heat - A Comparative Pore Level Evaluation
Authors: Bayestehparvin B. , Abedi J. , Ali S.M. Farouq 
Published: April 2016

Abstract
The first commercial test of solvents took place in California in 1960 where solvent stimulation was used to increase production of heavy oil. Currently, successful performance of steam injection in horizontal wells suggests the idea of using hot solvent alone or in conjunction with steam to reduce bitumen viscosity. The present study compares the performance of heat, cold solvent, and hot solvent for reducing bitumen viscosity at the pore scale using typical field data.
The governing equations were derived for heat transport by conduction and convection and solvent diffusion and dispersion. The equations were solved in spherical geometry for a droplet of bitumen at different flow rates. In addition to solvent and steam together, equations were derived for a hot solvent. The mass and heat balance equations were solved simultaneously and the viscosity profile was obtained. The performance of different solvents at different temperatures was compared with heat under the same conditions.
The results indicated that hot solvent is much more effective than solvent alone due to the effect of temperature on oil viscosity. It was found that the effect of solvent is much less than that of heat and that the high recovery by heated solvent is directly related to the heat. The time required for cold solvent to reduce bitumen viscosity was much longer compared to conduction-convective heating even at high solvent rates. Hot solvent shows promise compared with conduction-convective heating as a result of the heat contribution.
In spite of the benefits of using solvent, the economics must be considered. This study improves our understanding of the mechanistic behavior of solvent assisted recovery processes and modelling approaches at the pore scale.
Effect of Temperature Variations on Asphaltene Dynamics in Oil Reservoirs
Authors: Darabi Hamed , Abouie Ali , Sepehrnoori Kamy 
Published: April 2016

Abstract
Asphaltene precipitation, flocculation, and deposition strongly depend on the pressure, temperature, and composition variations (e.g. phase instability due to CO2 injection). The effect of temperature variations on asphaltene precipitation is more complicated compared to the other factors. As temperature increases, oil density decreases while at the same time entropy of the solution increases, resulting in a counter balancing effect. Although some researchers addressed this issue in the literature, there is a lack of comprehensive model that investigates dynamic effect of temperature variations on asphaltene behavior.
In this paper, a comprehensive non-isothermal compositional EOS-based reservoir simulator is developed with the capability of modeling asphaltene phase behavior to study the effect of temperature variations on dynamics of asphaltene precipitation, flocculation, and deposition during cold/hot water injection. The results showed that effect of temperature variations might be favorable or detrimental on oil production, depending on fluid composition, direction of wettability alteration, and dynamic changes in reservoir condition. Each of these factors has a distinct effect on the asphaltene behavior, and neglecting such effects may result in a significant error in the prediction of asphaltene behavior, and consequently, oil production rate.
Improved Oil Recovery in Asphaltic Reservoirs During Gas Injection
Authors: Darabi Hamed , Abouie Ali , Sepehrnoori Kamy 
Published: April 2016

Abstract
A successful gas injection design is a challenging task in asphaltic reservoirs. Gas injection accelerates asphaltene deposition, which results in detrimental effects on field development and ultimate oil recovery. The main objective of this paper is to provide a workflow to mitigate asphaltene problems in reservoirs during gas injection. The workflow includes data gathering, fluid characterization, and dynamic asphaltene modeling using an in-house compositional reservoir simulator. The in-house simulator is capable of modeling (1) the effects of pressure, temperature, and composition variations simultaneously on asphaltene phase behavior, (2) asphaltene precipitation, flocculation, and deposition, and (3) wettability alteration due to asphaltene deposition. Three case studies were presented to investigate the effects of gas flooding, gas override, and wettability alteration on the dynamics of asphaltene precipitation, flocculation, and deposition.
The simulation results showed that gas injection considerably increased the instability of asphaltene particles in the oil, and consequently, accelerated asphaltene precipitation and deposition in the reservoir. During miscible gas flooding, asphaltene mostly deposited at the front near the boundaries, where the front velocity was minimum. Moreover, asphaltene deposition occurred mainly in the bottom layer in the presence of gas override due to the lower velocity of the front in the bottom layer compared to the upper layer. Finally, the study revealed that wettability alteration due to asphaltene deposition had a major impact on the performance of the reservoir, specifically on the ultimate oil recovery, compared to the permeability reduction.
Characterizing Reservoir Connectivity and Forecasting Waterflood Performance Using Data-Driven and Reduced-Physics Models
Authors: Artun Emre 
Published: April 2016

Abstract
Closed-loop reservoir management requires representative models that can be updated quickly. Such kind of models that can be used for characterization of reservoir connectivity would greatly contribute to decisions in waterflooding operations. In heterogeneous reservoirs that are characterized with thief-zones/fractures or flow-barriers, that may enhance or prevent connectivity, it becomes challenging to construct geological models with both reasonable accuracy and computational efficiency. In this study, practical and computationally-efficient methods are presented to first accurately characterize the connectivity between producer and injector wells, and then to forecast the waterflood performance. Two classes of modeling approaches are evaluated in terms of their applicability to characterize the connectivity: 1) Data-driven modeling - artificial neural networks (ANN), in which there is not any presumed functional relationship and connectivity is derived from the weights on connection links of neural networks; 2) Reduced-physics modeling - capacitance-resistance models (CRM), in which physics are incorporated with certain assumptions and connectivity is derived from the fractional flow parameter in the formulation. In both approaches; a producer-based control volume is considered to focus on producers and their connectivity to different injectors, and both models are trained with injection/production histories. Connectivity values derived from these methods are fed into a short-term, pattern-based forecasting methodology, which quantified ultimate recoveries at the desired oil-cut values. Two synthetic reservoir models are used to test the applicability of aforementioned methods; which are characterized with high-permeability streaks and flow-barriers. These key features that affect connectivity are identified by both modeling approaches with reasonable accuracies, but with varying interpretations of fluid movement in the reservoir. Pattern-based forecasting methodology resulted in ultimate recovery predictions very close to the numerical-model based results, with errors within 3%. The workflow presented is quick and reliable to be implemented in closed-loop reservoir management protocols, which requires models that can be updated easily with recent data, and can be used in decision making processes with confidence.
Customized Drilling & Completion Fluids Designed for Horizontal Wells to Address the Drilling and Production Challenges - Case History
Authors: Soliman Ahmed , Samir Ahmed , Sheer Shahad , AL-Khaldi Ali , Boukhamsin Ali 
Published: April 2016

Abstract
This paper presents drilling and completion fluids design for drilling long lateral / horizontal wells in a North Kuwait field and its field application on well RA-AAA, RA-BBB, RA-CCC and RA-DDD. The offset wells were reviewed to identify the issues from drilling a challenging trajectory through troublesome reactive formations that showed serious wellbore stability issues and stuck pipe incidents.
The customized drilling and completions fluids system was designed for different intervals, taking the following objectives in consideration: Improved hole stability through stressed and reactive formationsEnhanced hole-cleaning efficiency at critical anglesMinimized risk of stuck pipe across depleted formations with high porosity and permeabilityMinimized / no induced losses to formation by utilizing unique wellbore-strengthening techniqueMinimal damage to reservoir section during drilling phaseNear-wellbore damage remediation during completion phase
This paper describes the customized drilling and completions fluids performance as compared to offset wells. A comprehensive engineered approach addressed the challenges of drilling horizontal wells by using a revolutionary bridging technology to strengthen the wellbore and improve wellbore stability to reduce non-productive time (NPT) related to losses, stuck pipe, etc. This paper also describes the completions fluids design to minimize reservoir damage and utilize Mesophase technology to remediate near-wellbore damage and improve reservoir producibility. The lessons learned on these wells were incorporated in drilling subsequent wells to continue improve on performance.
Rigorous and Explicit Determination of Reserves and Hyperbolic Exponents in Gas-Well Decline Analysis
Authors: Stumpf T. N. , Ayala Luis F. 
Published: April 2016

Summary
Reservoir evaluation on the basis of rate-time data of gas wells producing under boundary-dominated flow (BDF) is often performed with the Arps’ empirical hyperbolic decline model and associated type curves. In this study, we show that, for volumetric, single-phase, gas reservoirs produced at constant bottomhole pressure, the decline exponent, b, used in Arps’ hyperbolic model can be calculated solely on the basis of fluid properties and the prevailing bottomhole specification—regardless of reservoir properties and before collecting any rate-time data. For the case of real gases produced under less-than wide-open decline, the assumption of a constant b necessary for the use of Arps’ equations does not hold true throughout the production life of a reservoir. We show that during early BDF, a hyperbolic window may be defined for which the constant-b assumption may be valid. Within this window, we show that the application of type-curve and straight-line analysis techniques derived from the hyperbolic model can be used to successfully and explicitly determine reservoir properties, including original gas in place (OGIP). Several case studies based on numerical simulation and field data are presented to thoroughly validate and highlight the predictive capabilities of the proposed model.
The Analysis Of Creative Writing Teaching Through Story Book Reading For The First Grade Students Of Tunas Muda International School
Authors: Agus Jaclyn Ryani , Winiharti Menik 
Published: April 2016

One method to support the success of teaching of writing skills is using story books. It has many kinds of benefits that provides the students more creative and challenging texts that require personal exploration, easier understanding of information which are commonly hard to comprehend and remember, and easier illustration in making connection among various elements and concepts being taught. This research deals with teaching creative writing through story book reading, and it is aimed at finding whether this method is beneficial or not in increasing creativity in writing. The study is carried out using a pre-test and post-test design to 14 students from the first grade. Between the two tests, the students were provided with basic knowledge of creative writing. The data of the research were the scores of the pre-test and post-test compared and analyzed based on the rubric of ideas, organization, word choice, sentence fluency, and conventions. The pre-test result shows that 29% of the students achieve the standard of achievement. After the creative writing process, the post-test result indicates that 93% of the students achieve the standard of student achievement in creative writing.
Karakter Han Dengan Radikal 示 Dalam Shuowenjiezi: Klasifikasi, Aktivitas Penyembahan, Perbandingan Dengan Kamus Xiandai Hanyu
Authors: Sahertian Diana C. 
Published: April 2016

The writing system used in the Chinese language is different from the Latin characters used in the Indonesian language. While the Latin characters represent sounds, the Han characters of the Chinese language represent meanings. Some Han characters have a component called a ‘radical’. This paper discusses Han characters with the 示 radical in Shuowen jiezi. The first part consists of the classification of such characters based on their structure and meaning. The second part discusses the worship practices on which the characters are based. The last part of this paper compares these Han characters to those with the same 示 radical in the Xiandai Hanyu Dictionary.
Motherhood in the American Woman Poet’s Perspective: A Short Glance at Allen’s Rock Me to Sleep
Authors: Kurnia Nandy Intan 
Published: April 2016

Article scrutinized one of the works of an American woman poet named Elizabeth Akers Allen. The poem under study entitled “Rock Me to Sleep”. It was a portrayal of motherhood. The speaker of this poem is a woman who is longing for the love of her mother. She is seeking for a way to ease her pain since she feels that she has lost her own battle of womanhood. Although the mother remains absent, the readers of the poem can sense the powerful love of the speaker of the poem toward her mother. Method of this study was library research that carried out by applying descriptive analytical methods. Data were collected from the primary and secondary sources. Results of this paper are the writer of poetry wants to warn people that womanhood in the patriarchal society can create many problems, and the only remedy for those problems is motherhood. Article also proves that a writer does not have to be a feminist to produce a literary text which discusses the issue of women, which has became the focus of feminism.
An automatic approach for tagging Web services using machine learning techniques
Authors: Lin Maria , Cheung David W. 
Published: April 2016

Web services have become popular and increasingly important in e-business and e-commerce applications especially in large scale distributed systems. As a result, an increasing number of Web services have been developed. However, this huge collection of Web services makes the task of locating a suitable one more challenging as well as more difficult. Automatic clustering of Web services groups services with similar functions together. Clustering could greatly boost the power of Web service search engines and generate tags to improve the search accuracy of tag-based service recommendation. In this paper, we propose a Web service clustering technique based on Carrot search clustering and K-means to group similar services together. These clustered groups are then tagged. We also develop a tag-based service recommendation for WSDL documents using naive bayes algorithm to classify Web services into different tags. We demonstrate that the proposed clustering approach is effective for Web service discovery through two sets of real data.
Les écoles de management jouent-elles un rôle dans la lutte contre le plafond de verre ?
Authors: Borel Pascale , Soparnot Richard 
Published: April 2016

Aujourd’hui encore, des inégalités professionnelles entre les hommes et les femmes perdurent. Ce constat a nourri de nombreuses recherches qui ont permis d’identifier les facteurs explicatifs de ce qu’on appelle « le plafond de verre », exprimant les obstacles, visibles ou invisibles, que rencontrent les femmes dans la progression de leur carrière. S’appuyant sur l’analyse des facteurs à l’origine du phénomène de plafond de verre et sur la Charte pour l’Égalité entre les Femmes et les Hommes engageant les écoles de management à agir en faveur de l’égalité professionnelle, ce travail pose la question plus générale du rôle que peuvent jouer ces établissements pour lutter contre les inégalités de genre. Dans le cadre d’une approche exploratoire, ce travail se propose d’appréhender la manière dont les écoles de management se sont approprié la problématique du plafond de verre. Une analyse de leur communication Web fait ressortir que seules quelques écoles de management sont engagées au niveau institutionnel sur les différents leviers d’action de lutte contre l’édification du plafond de verre.