bluuebunny/crossref_metadata_2025_split huggingface dataset:
Validation of the academic management evaluation instrument based on principal component analysis for engineering and technological courses
Authors: Nunes Albano Oliveira , Silva Thomaz Edson Veloso da , Mota João Cesar Moura , Almeida André Lima Ferrér de , Andriola Wagner Bandeira 
Published: August 2015

<p class="Abstractandkeywordscontent"><span lang="EN-US">In recent years, the expansion of higher education in Brazil has led to a series of demands related to aspects concerning training at the college level. These processes relate to: academics, professionals, entering in the labor market, among others. In this context, an important aspect is the quality of the courses. Thus, the evaluation becomes a critical diagnostic process of reality and starting point for possible interventions to be put in practice by the coordinators of the programs. This article presents the results of a questionnaire administered at the Federal University of Ceará (UFC), especially to Systems &amp; Digital Media and Engineering Programs professors. This research aims to identify how the professors from each department see the administrative procedures developed by the departments and also investigate the possibility of using Principal Components Analysis (PCA) as a support for management of the higher education training. The methodology included the implementation of Likert scale questionnaire and subsequent mathematical treatment with PCA. The results indicate the potential application of PCA to support the management of higher education; it was possible to extract preliminaries inferences related to management methods and their characteristics. <span class="hps">This suggests</span> <span class="hps">the possibility</span> <span class="hps">of developing the</span> <span class="hps">Educametrics field.</span> </span></p>
Effect of pH on the rheological response of reconstituted gastric mucin
Authors: Caicedo Jonathan Argenis , Perilla Jairo Ernesto 
Published: August 2015

<p class="Abstractandkeywordscontent">The rheological response of reconstituted gastric mucin was studied by time dependent rheological experiments as function of pH. Mucin concentrations of 5% and 10% were prepared in buffer dispersions at pH of 1.15, 2.00, 2.55, 4.00 and 7.67. The isoelectric point was identified by z-potential between pH 2.00 to 2.55. Dynamic light scattering showed that as pH reduced, a second population of larger mucin aggregates was formed indicating the presence of new structures. Steady shear rheological measurements reflected the pseudoplastic behavior of mucin dispersions and the effect of concentration on viscosity. Creep-recovery measurements were performed on the regenerated mucus at different levels of pH. By creep, it was possible to determine the values of zero-shear-viscosity of mucin suspensions, with higher precision and in a lower experimental time than steady shear measurements. Additionally, it was found that at pH ~1.15, the viscosity of the mucus increased to high values, which is an indicative of a gel-like structure. By recovery experiments, it was possible to find that even the very low viscosities the mucin suspensions at pH ~1.15 possessed a defined elastic character. By the use of a four-element mechanistic viscoelastic model, it was concluded that this elasticity underwent retardation due to the combined effect of viscous and elastic responses.</p>
Studies on the weldability, microstructure and mechanical properties of flux assisted Nd:YAG laser welds of AISI 904L
Authors: Devendranath Ramkumar K. , Chaitanya Gangineni , Narasimha Varma Jelli Lakshmi , Choudhary Ayush , Arivazhagan N. , Oyyaravelu R. 
Published: August 2015

Abstract
Current Developments and Remaining Challenges of Chemical Flooding EOR Techniques in China
Authors: Zhu Youyi 
Published: August 2015

Abstract
Chemical flooding EOR techniques, mainly including polymer flooding, chemical combination flooding and foam flooding, play a crucial role in Chinese oil industry. Field tests proved that chemical flooding EOR techniques could be applied successfully in onshore reservoirs in China. Challenges were also presented as the chemical flooding EOR were applied in different reservoirs. The current developments of chemical flooding EOR techniques were introduced, the chemical flooding field tests were summarized and remaining challenges were discussed in this paper.
Polymer flooding has entered into commercial applications stage. By the end of 2011, 54 industrial blocks of polymer flooding have been applied in Daqing Oilfield with 13% incremental oil recovery over water flooding in average. Ten key techniques for polymer flooding have been developed involving polymer screening and evaluation, low viscosity loss facility of injection, high performance polymer preparation and injection equipments and crafts, eccentrically-wearing inhibiting technology, separated layer injection etc. Chemical combination flooding especially ASP flooding has been studied and tested intensively in China. Six pilot and four industrial field tests of ASP flooding have been implemented. More than 20% incremental oil recovery after water flooding has been obtained. A set of techniques for combination flooding have been formed such as ASP formulation optimizing, injection allocation technology, lifting technology, chemicals monitoring of produced liquid etc. Twenty foam flooding pilot tests have been carried out in China, and sixteen of them showed good performances.
Challenges of polymer flooding are mainly focused on the development of new effective polymers for specific reservoir conditions such as high salinity, high temperature, and low permeability reservoirs. The limitations of ASP flooding were known as the scaling problem and difficulty in produced liquid treatment. Challenges in foam flooding were mainly the gas finger problem usually occurred in field tests. Some progresses have been made in recent research and shown good perspectives.
Effects of Emulsification on Oil Recovery and Produced Liquid Handing in Chemical Combination Flooding
Authors: Zhu Youyi , Lei Ming , Zhang Yi 
Published: August 2015

Abstract
It was an argued issue concerning effects of emulsification in chemical combination flooding process. For example, it may increase oil displacement efficiency. On the other hand, it makes the produced liquid handing to be more difficult. How does emulsification impact on oil recovery and produced liquid handing, and how to control emulsification degree are significant issues that are greatly concerned by engineers.
Effect of emulsification on oil recovery of chemical combination flooding was investigated based on emulsification intensity index quantitative measurements and Berea core flooding experiments. Field tests results domestrated that emulsification could remarkably influence oil recovery and produced water handing process.
Core flooding tests showed that enhanced oil recovery by strong alkaline alkali-surfactant-polymer (ASP) flooding, weak alkaline ASP flooding and surfactant-polymer (SP) flooding was different under the same interfacial tension (IFT), viscosity and slug size conditions. The incremental oil recovery after water flooding was about 23%-25%, 20%-23% and 17%-19% respectively as chemical slug size of 0.5PV. The emulsification intensity indexes for different formula were measured. It indicated that the sequence of emulsification intensity index of the three kinds of flooding systems was strong alkaline ASP flooding &gt; weak alkaline ASP flooding &gt; SP flooding. Core flooding experiments of chemical combination flooding with serial emulsification intensity index showed that incremental oil recovery could be increased by 6%-10% with stronger emulsification degree than that with weaker emulsification index.
ASP flooding field tests in Daqing Oilfield showed the different results in incremental oil recovery between strong alkaline ASP and weak alkaline ASP floodings. Emulsion stability of produced liquid from strong alkaline ASP flooding was stronger than that from weak alkaline ASP flooding. The special de-emulsifier and more complicated liquid treatment process were used in strong alkaline ASP flooding field tests. The cost was much higher than that of weak alkaline ASP flooding.
From the above experiments and field tests results, moderate emulsification is necessary for chemical combination flooding. From the view of overall investment and outcome ratio, weak alkaline ASP flooding may be more favorable for expanding application in oilfield than its counterpart of strong alkaline ASP flooding.
Constructing High Productivity Wells with High Wellbore Dynamic Flow Stability for EOR Projects
Authors: Chan Keng Seng , Masoudi Rahim , Karkooti Hooman , Othman Mohamad , Tan Chee Phuat , Anis Apollinaris Stefanus , Press David , Setiawan Ngurah Beni 
Published: August 2015

Abstract
A method of constructing high productivity and high wellbore dynamic stability wells has been developed for EOR field development application. It integrates a heuristic reservoir engineering modelling method for determining optimum drainage points with high dynamic flow and a 3D coupled reservoir geomechanical modelling method for identifying low sanding propensity regions within the entire reservoir. The reservoir geomechanical method couples dynamic reservoir modelling with geomechanical modelling. It can account for in-situ stress changes associated with reservoir pressure change, and predict any potential geomechanical-related physical events for the remaining life of the field. Correspondingly, the generated drainage map and 3D sand production critical drawdown cubes can then be combined to identify global optimum well placement locations within the reservoir, layer by layer.
Drainage points selected by this heuristic reservoir modelling method can be correlated with their respective EUR (Estimated Ultimate Recovery) values, while the 3D critical drawdown cubes can identify reservoir regions with low sanding propensity. This combined approach can therefore lead to the development of multi-layer commingle wells having various angles of reservoir penetration, for optimizing well productivity and EUR value without the requirement of sand control. Illustrated by a case study in brownfield reservoirs, a non-linear well trajectory which maximizes reservoir fluid contact in a prolific sand layer can be designed without any sand control completion for sanding mitigation through optimization and management of production plan.
Technical Challenges in the Conversion of CO2-EOR Projects to CO2 Storage Projects
Authors: Al Eidan A. A. , Bachu S.. , Melzer L. S. , Lars E. I. , Ackiewicz M.. 
Published: August 2015

Abstract
While enhanced oil recovery using carbon dioxide (CO2-EOR) is a mature technology and known to concurrently store large volumes of CO2, it is not currently viewed by industry as a CO2 storage process. Application of CO2-EOR for CO2 storage to reduce anthropogenic CO2 emissions 1) enables carbon capture and storage (CCS) technology improvement and cost reduction; 2) improves the business case for CCS demonstration and early movers; 3) supports the development of CO2 transportation networks; 4) may provide significant CO2 storage capacity in the short-to-medium-term, particularly if residual oil zones (ROZ) are produced and hybrid CO2-EOR/CCS operations are considered; 5) enables knowledge transfer; and 6) it helps gaining public and policy-makers acceptance. Although there are a number of commonalities between CO2-EOR and pure CO2 storage operations, currently there are a significant number of differences between the two types of operations that can be grouped in five broad categories: 1) operational; 2) objectives and economics, including CO2 supply, demand and purity; 3) legal and regulatory; 4) long term CO2 monitoring requirements; and 5) industry's experience. There are no specific technological barriers or challenges per se in adapting or converting a pure CO2-EOR operation into a CO2 concurrent or exclusive storage operation. The main differences between the two types of operations stem from legal, regulatory and economic differences between the two. The legal and regulatory framework for CO2 storage is being refined and is still evolving and it is clear that CO2 storage operations will likely require more monitoring and reporting. Because of this, CO2 storage will impose additional costs on the operator. A challenge for existing CO2-EOR operations which may, in the future, adapt to concurrent or exclusive CO2 storage operations is the lack of baseline data for monitoring, except for wellhead and production monitoring for which there is a wealth of data. Thus, in order to facilitate the transition of a pure CO2-EOR operation to concurrent or exclusive CO2 storage, operators and policy makers have to address a series of legal, regulatory and economic issues in the absence of which this transition cannot take place.
A Holistic Approach to EOR Screening in Dual-Porosity Naturally Fractured Reservoirs
Authors: Moreno Jaime E. , Gurpinar O.. , Liu Y.. 
Published: August 2015

Abstract
While the principles of enhanced oil recovery (EOR) are not new, field implementation has been scarce, particularly in the case of dual-porosity naturally fractured reservoirs, where the interaction of two different porous media creates a more complex displacement process. Several approaches to define the screening criteria on dual-porosity reservoirs have been postulated; the evaluation of the matrix-fracture interaction still requires complex models for proper EOR selection.
This paper offers a multidimensional approach to EOR selection in dual-porosity naturally fractured reservoirs, starting with a detailed analysis of the matrix-fracture system and including: transmissivity/storativity ratios, fracture geometry, matrix block size, and dominant recovery mechanisms. Historical observations are used for characterization and identification of areas where one porous media is dominant and to help shortlist the desired EOR methods on an area-by-area basis.
Two levels are considered in the analysis: the first level allows for a qualitative EOR ranking, suitable for reservoirs with limited information. The next level (numerically intensive) provides a quantitative EOR ranking with basic economics. The first-level ranking uses four different criteria for the selection—namely, pore-level displacement efficiency of the matrix-fracture system, EOR agent compatibility, matrix-fracture geometry, and the distribution of moveable hydrocarbons—and an internal advisor-system to achieve the ranking based on the fluid and reservoir properties.
A combination of analytical and numerical models is systematically used to overcome the challenge of estimating pore-level displacement efficiency when the EOR agent contacts matrix and fracture systems simultaneously (including all the relevant recovery mechanisms, such as gravity drainage). An advisor system based on a global EOR project database, merged with in-house EOR engineering expertise, complements the EOR selection. Numerical modeling is used at a later stage to further substantiate and quantify the EOR solution, allowing for a full-cycle comparative evaluation.
It is worth mentioning that the advisory EOR system presented here not only tackles a highly challenging topic but also provides “dynamic engineering guidance” throughout the EOR selection process. The authors believe that combining this reliable engineering process with ever-increasing computation power will help our industry to identify EOR potential easily.
Optimization of Gas Assisted Gravity Drainage (GAGD) Process in a Heterogeneous Sandstone Reservoir: Field-Scale Study
Authors: Al-Mudhafar Watheq J. , Rao Dandina N. 
Published: August 2015

Abstract
Gas injection has been widely used for IOR/EOR processes in oil reservoirs. Unlike the conventional modes of continuous gas injection (CGI) and water –alternative gas (WAG), the Gas Assisted Gravity Drainage (GAGD) process takes advantage of the natural segregation of reservoir fluids to provide gravity stable oil displacement. It has been proved that GAGD Process results in better sweep efficiency and higher microscopic displacement to recover the bypassed oil from un-swept reservoir regions. Therefore, CO2 was considered in this research for immiscible injection in the main pay/upper sandstone formation in South Rumaila oil field located in Iraq through the GAGD process application. This field, with a 60-year production history, has 40 production wells and is surrounded by an infiniteacting edge water aquifer from the east and the west flanks. Since the east flank is much less effective than the west one, 20 injection wells have been drilled at the east flank over the last 35 years to maintain the reservoir pressure. The formation depth is 10350 ft. sub-sea with a maximum vertical oil column of 350 ft.
The GAGD process was adopted here using compositional reservoir simulation and PVT modeling to increase oil recovery. The GAGD process consists of placing a horizontal producer near the bottom of the payzone and injecting gas through existing vertical wells that have been used in prior waterfloods. As the injected gas rises to the top to form a gas zone, oil and water drain down to the horizontal producer. The location of horizontal wells is slightly above the oil-water contact.
In the reservoir modeling, different reservoir and fluid properties have been investigated their effect on the flow response to implement sensitivity analysis, history matching through Design of Experiments. The operational design parameters of production/injection wells were considered to determine the optimal future reservoir performance through the GAGD process. Among many prediction scenarios, the GAGD process led to significant recovery incremental, especially in early future production years in comparison with the base case of no injection and 10,000 barrels of water injection per well in the same injection wells.
Development of Novel Surfactant for Alkali-free Surfactant/Polymer Combination Flooding Green Technology
Authors: Zhang Fan , Zhang Qun , Zhou Zhaohui , Cai Hongyan 
Published: August 2015

AbstractAlkali - surfactant - polymer (ASP) combination flooding technique is one of the effective enhanced oil recovery ways for mature oilfields. However, alkali can lead to difficulty of the scaling and emulsification problems in lifting and produced liquid treatment. So alkali-free surfactant - polymer (SP) combination flooding is a green technology can solve these problems caused by alkali. The key technology of SP flooding is development low cost and high efficiency surfactants. In this paper, the novel betaine surfactant was synthesized with cheap raw material of fatty acid, which had intellectual property and excellent properties. Experimental results showed that the surfactant had wide adaptability and could achieve ultra-low interfacial tension (IFT, less than 1.0×10−2mN/m) in different reservoir conditions, not only for low temperature and low salinity oilfield (45°C, 5,100 mg/L), but also for high temperature and high salinity oilfield (90°C, 100,000 mg/L). The dynamic adsorptions of this betaine were less than 1.0 mg/g rock, and it could maintain ultra-low IFT for 9 times adsorption with the natural sand. The alkali-free SP formulations with the betaine had long term stability, and could maintain ultra-low IFT within 180 days, and the viscosity retention rates were greater than 90%. The systems of the novel betaine surfactant had good emulsifying capacity and stripping film capacity. The alkali-free SP formulations with the betaine had high oil-displacement efficiency. After water flooding, it could increase oil recovery 21.5% (OOIP, Original Oil In Place) in Daqing sandstone oilfield, 23.4% (OOIP) in high temperature and high salinity carbonate reservoir rock, 15.5% (OOIP) in Changqing low permeability oilfield. Excellent properties of this novel betaine surfactant indicate that it is a promising surfactant for alkali-free SP combination flooding applied in different reservoirs.
Alternative Injection and Its Seepage Mechanism of Polymer Flooding in Heterogeneous Reservoirs
Authors: Peihui Han , Haibo Liu , Xu Han , Ruibo Cao , Yuwei Zhang , Xiaoyang Liu 
Published: August 2015

Abstract
Field application proves that polymer flooding is an effective technology for improving development effect of heterogeneous reservoirs. Previously, single slug injection is performed. However, there are problems of profile reverse, non-effective circulation of polymer solution in high permeability zone, over much polymer dosage and so on. Thus a new technique of alternative injection for improving oil displacement effect of polymer flooding is developed. Some oil displacing experiments with different injection patterns are performed by using automatic oil displacement equipment and physical model of heterogeneous reservoir so as to study oil displacement efficiency of different alternative injection patterns. A series of polymer solution slugs with different molecular weight, concentration, viscosity and size are injected alternatively in the experiments and then reasonable alternative injection pattern is optimized and difference of displacement mechanism between single slug injection and alternative injection is illustrated. Meanwhile an evaluation method for the improvement effect of fluid absorption profile is introduced for the first time. Experimental results show that oil displacing effect of alternative injection is better than that of single slug injection and the incremental oil recovery is 2% more than that of single slug injection. Based on basic law of displacement mechanics and combined with experimental data, displacement mechanism of profile reverse and that of inhibiting profile reverse are demonstrated. The profile reverse is mainly due to different tendency of transient resistance factors in high and low permeability zones. Alternative injection can make this tendency the same and this is the main cause of alternative injection inhibiting profile reverse and increasing injection volume in low permeability zone so as to improve oil displacement effect. When alternative injection was applied in pilot tests of Daqing Oilfield, oil production is increased, while water cut increasing rate and polymer powder dosage are decreased. Application result shows that alternative injection is a new injection type of polymer flooding and is a effective measure to increase oil displacement efficiency and reduce polymer dosage.