bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical Modeling of Mineral Dissolution of Carbonate Rocks During Geological Co2 Sequestration Processes
Authors: Yuan Tao , Ning Yang , Qin Guan 
Published: March 2017

Abstract
Carbonate formation is an ideal candidate for geological CO2 sequestration (GCS) because of its large storage capacity. One of the important issues is the CO2 leakage through highly conductive pathways. During a GCS process, the dissolved CO2 can form a weak acid in brine that can dissolve carbonate rocks by various geochemical reactions. Carbonate rocks are composed of a variety of minerals, including calcite, quartz, clay, etc. Such dissolution process may enhance the existing natural fracture system to eventually form highly conductive pathways for possible CO2 leakage.
In this paper, we have developed a numerical model that couples the Stokes-Brinkman equation instead of the Darcy's Equation and a reactive transport equation, and applied for modeling of the coupled process consisting of fluid flow, solute transport, and chemical reactions. Compared to the Darcy's equation, the Stokes-Brinkman equation is a unified approach for modeling fluid flow in both porous media and free flow regions, which is an ideal candidate for modeling of porosity alteration and fracture enhancement due to mineral dissolution. The nonlinear reactive transport equations are derived for primary species from mass balance equations. In the numerical model, the Stokes-Brinkman equation and the transport reactive equations are solved by a mixed finite element method and the control-volume finite difference method, respectively, in a sequential fashion.
The numerical model is validated using a CO2-saturated brine flooding experiments from the existing publications. Good agreements of effluent concentrations of aqueous species can be found between our simulation results and experimental observations. The numerical simulation study focuses on core-flooding scenarios with different mineral volume fractions and different injection rates in fractured rocks composed of multiple minerals. The preliminary results demonstrated that the mineral volume fractions have significant impact on the porosity alteration and fracture propagation. The calcite dissolution is preferred in acidic fluids over less reactive minerals including quartz and clay, and the rock properties are altered accordingly. The competitive coupling between the flow and chemical reaction rates is another important factor for mineral dissolution in our simulation study. In addition, the simulation results demonstrated that mineral dissolution processes can be altered by controlling the injection rates because the chemical reactions in the GCS processes are reversible.
This work presents a mathematical model allowing us to simulate the dynamic behavior of natural fracture evolution during the GCS processes, and provides some important guidelines for the GCS implementation. Currently, we are trying to apply the simulation technology for solving some real-world problems.
Polynomial-Chaos-Expansion Based Integrated Dynamic Modelling Workflow for Computationally Efficient Reservoir Characterization: A Field Case Study
Authors: Patel Rajan G. , Jain Tarang , Trivedi Japan J. 
Published: March 2017

Abstract
Assisted history matching which integrates production data dynamically in reservoir modelling has been used to reduce uncertainty in reservoir geological properties which leads to credible production forecasting. For largescale heterogeneous heavy oil reservoirs, typically thousands of full physics simulation runs of multimillion grid reservoir models might be required to accurately probe the posterior probability space given the production history of reservoir, therefore not practical. In this paper, a unique approach for computationally efficient dynamic data integration is presented which includes construction of a proxy model that can replace reservoir simulator. Realizations are first parameterized using Karhunen-Loeve (KL) transformation and represented in terms of few uncorrelated random variables. Considering these random variables as input and production parameters as output, a mathematical model based on Polynomial Chaos Expansion (PCE) is constructed using deterministic coefficients and orthogonal polynomials which is further employed in assisted history matching instead of computationally expensive reservoir simulator. History matching of a SAGD field located in northern Alberta is performed using proposed KL-PCE framework and results are compared with the base case that uses commercial reservoir simulator. Ensemble Kalman Filter (EnKF) is used for assisted history matching due to its ability to assimilate data in large-scale nonlinear systems. Effectiveness of proposed idea is evaluated based on the following criteria: (1) Does KL-PCE framework reduce computational cost significantly, and (2) does proposed workflow produce satisfactory history matching results? It is observed that KL-PCE based proxy model provides similar performance as a commercial simulator in terms of ensemble convergence. Also, uncertainty in geological parameters is reduced significantly which is evident from convergence of updated ensemble towards the true value. Furthermore, computing cost of assisted history matching is reduced by almost 95% as training of PCE needs only few full physics simulations. Finally, proposed surrogate-accelerated integrated dynamic modelling can be used in greenfield closed-loop optimization workflows and uncertainty assessment with minimal use of numerical simulator which ultimately maximize the benefit in monetary terms.
Calibration of the Mixing Parameter Model for Viscous Fingering for Varying Water Alternate Gas WAG Ratios and Slug Sizes
Authors: Al-Haboobi Zainab Imad , Christie Mike , Arnold Dan 
Published: March 2017

Abstract
Water alternating gas (WAG) injection is a method of controlling the viscous fingering impact in a miscible flooding processes to improve the volumetric sweep efficiency. The WAG technique is a mix of two conventional techniques: gas injection to improve the microscopic displacement efficiency and water flooding to improve the sweep efficiency. Overall, WAG improves the oil recovery.
Conventional reservoir simulation is too coarse to resolve fingers accurately at field scale. This is because the fingers maybe smaller than field scale grid blocks. Instead, empirical models are used to describe the fingers and to allow simulators to predict realistic recovery.
Effective parameter models such as Todd and Longstaff (1972) are used to model the effects of viscous fingering in field scale. This model is the most commonly used among different reservoir simulators, because it requires the selection of a mixing parameter, ω, whose value includes all of the factors affecting fingering. Additionally, it incorporates a method to calculate the effective viscosity when mixing occurs between oil and gas phases.
Todd and Longstaff (1972) recommended a mixing parameter ω = 2/3 for miscible injection to match the recovery of oil from Blackwell et al.'s (1959) experiments. They recommended ω = 1/3 - 2/3 to account for field scale heterogeneities.
Blunt and Christie (1993) showed that the mixing parameter, ω, needs to be calibrated for WAG injection. They calibrated the value of the mixing parameter, ω, as a function of the fractional flow of injected water. These equations are self-consistent, modified from the effective Todd and Longstaff mobility ratio and have been precisely solved in one dimension to account for fingering in three component systems. But their work was limited to simultaneous injection of water and gas.
In this paper we examine how calibration of ω varies with finite slug size for different WAG ratios using a 1D model. The results show that as the slug size increases, the value of mixing parameter ω, decreases. The value of mixing parameter ω is computed to match the concentration and saturation profiles from 2D simulation.
Updating Reservoir Simulation Models with Well Test Information for Reduction of Uncertainties in Early Field Development
Authors: Toledo S. , Avansi G. D , Schiozer D. 
Published: March 2017

Abstract
The high level of uncertainties during early phases of oilfield projects makes economic decisions challenging. One effective way to reduce uncertainties is gathering reservoir information from dynamic sources, such as well tests and production logging. This data must be incorporated into reservoir characterization integrated studies to generate probabilistic simulation models (scenarios). The objective of this work is to develop a procedure to update reservoir simulation models during reservoir characterization including well test and production logs, aiming better production forecasts.
The proposed methodology consists in generating phi vs. log(k) equations derived from well test and production logging interpretation to update the permeability distribution in probabilistic scenarios without losing geological consistency. We also establish criteria for selecting wells to be tested based on openhole log data. We evaluate the result of the well this data incorporation in a synthetic field based on data from a real reservoir located in Campos Offshore Basin, Brazil. Then, we compared the results with the same reservoir model using classical phi-log(k) equations from laboratory experiments.
Results showed that well test and production logging incorporation can improve the performance of the field measured by the risk curve of the net present value compared to the case without tests. We also showed how the history matching of the pressure derivatives can reduce variability of the prediction of the reservoir future behavior.
The main contribution of this work is to evaluate how new information derived from well test and production logging improves the consistency of geomodels in early development of petroleum fields. Besides this improvement, the results also indicate that this methodology is an efficient way of reducing variability in the production forecast when integrated to other techniques such as history matching. The use of a benchmark case allowed us to show the influence of the quality of the simulation model in the process.
A New Environmentally Friendly Technique to Extend the Limits of Transient Pressure Testing and Sampling Using Pipe Conveyed Open Hole Wireline Formation Testing Tools
Authors: Ayan Cosan , Mishra Vinay , Eriksen Kåre-Otto , Van der Hoek Jeroen , Thorne Tyson 
Published: March 2017

Abstract
Transient well testing is one of the most critical components of reservoir evaluation due to its impact on a project's key economic parameters such as reserves and producibility. A conventional cased hole well test involves casing off the well, installing process equipment, completing the well perforating, flowing the well to surface and flaring the produced fluids. While the data acquired from conventional well tests is very useful; a large number of wells are not tested due to time, cost and regulatory constraints. In such situations with no well test, operators are obliged to take important decisions from a relatively small amount of reservoir information and hence take risks associated with subsurface uncertainties. To help reduce the development risks, a new pipe conveyed testing tool referred as Formation Testing While Tripping (FTWT) was developed. The new testing tool integrates a number of innovations allowing pumping large fluid volumes at higher rates with extended testing time and improved well noise control. This is done by circulating the produced fluids out of the wellbore during pumping out formation fluids. The new hardware can be combined with wireline sampling and downhole fluid analysis modules allowing to achieve overall well testing objectives; including collecting pressure transient data, real time fluid typing and capturing cleaner and larger volume fluid samples, while increasing the radius of investigation for better characterization of any reservoir heterogeneities compared to conventional wireline formation testing techniques.
In this paper, we introduce the new testing technique, which has recently been utilized in the Norwegian sector of the North Sea and offshore Canada. In one well, following the FTWT surveys, Drill Stem Tests (DST) were also conducted for comparison. The field examples and comparison with DST's indicated that the new method can provide valuable reservoir information while also showing its current limitations.
Well, Reservoir and Facility Management – Process, Practice and Impact
Authors: Vliet J. P. , Male P. T. 
Published: March 2017

Abstract
This paper presents an overview of how the Shell Group of Companies has implemented the Well, Reservoir and Facility Management (WRFM) methodology in its Upstream assets. It discusses the different parts of the WRFM Value Loop, and presents case histories and successes from within the Group.
Effective Well, Reservoir and Facility Management requires the integrated contributions of Petroleum Engineering, Production, Facilities and Process Engineering, and Well Services. The detailed WRFM plan defines the type and frequency of the surveillance and data acquisition activities that need to be carried out in order to optimise the production from the asset, and to manage the uncertainties that remain in the development of the asset. WRFM is a structured and integrated approach to data gathering and data management, modeling and interpretation, identification of production enhancement opportunities, and intervention to deliver the opportunities to maximise asset value. This process is represented as the WRFM Continuous Improvement loop, or Value Loop. WRFM targets are set on a yearly basis and progress is measured against the targets. Information and best practices are shared laterally and through the company's global WRFM team.
The various segments of the WRFM loop are presented below in detail, and are illustrated by appropriate case histories. Rigorous application of the WRFM methodology has resulted in considerable improvements in production gains and water injection performance.
Implementasi pembelajaran anak usia dini berbasis budaya lokal di PAUD full day school
Authors: Muzakki Muzakki , Fauziah Puji Yanti 
Published: March 2017

Tujuan dari penelitian ini yaitu mendiskripsikan implementasi pembelajaran anak usia dini berbasis budaya lokal di lembaga PAUD full day school. Jenis penelitian ini merupakan penelitian kualitatif dengan pendekatan studi kasus tunggal (single-case study). Penelitian ini di Lembaga PAUD full day school Fairuz Aqila Kalasan Sleman yang merupakan salah satu lembaga PAUD di Daerah Istimewa Yogyakarta yang menerapkan budaya lokal. Teknik pengumpulan data yang digunakan yaitu observasi, wawancara, dokumentasi dan trianggulasi. Hasil penelitian yang diperoleh yaitu implementasi pembelajaran anak usia dini berbasis bu-daya lokal dimulai dengan mengidentifikasi kebutuhan anak, menentukan tema pembelajar-an, menyusun perencanaan pembelajaran yaitu program kegiatan tahunan, program kegiatan mingguan dan program kegiatan harian. Proses pelaksanaan pembelajaran berbasis budaya lokal terintegrasi dalam kegiatan pijakan, kegiatan inti dan kegiatan pengasuhan. Penilaian pembelajaran yang digunakan yaitu dengan observasi, anekdot dan daftar chek list. Unsur-unsur budaya lokal yang digunakan yaitu tata nilai dalam budaya Jawa, sistem keagamaan, per-mainan tradisional, makanan tradisional, tarian Jawa, bahasa Jawa, sistem mata pencaharian, lagu Jawa, alat musik tradisional dan cerita rakyat.Kata kunci: pembelajaran budaya lokal, anak usia dini, PAUD full day school The Implementation of Learning Process Based on Local Wisdom in Full Day School Early Childhood Abstract The objectives of this study are to describe the implementation of local wisdom in full day early childhood school. This study applies qualitative research with a single-case study approach. This research is done in Fairuz Aqila institution in Kalasan, Sleman which is an early childhood education center in Daerah Istimewa Yogyakarta which applies local wisdom. The data of the research were collected through observation, interview, documentation, and triangulation. The results of the study showed that the implementation of full day early childhood school based on local wisdom is applied by identifying the children’s need, determining the topic of learning, arranging lesson plan which includes program planning of annual,weekly, and daily activity programs, integrating local wisdom into learning process through the basic, main, and day care activity, applying learning assessment by means of observation, anecdote, and check list. The elements of local wisdom which are acknowledged are Javanese culture norms, religious system, traditional games, traditional foods, Javanese traditional dance, Javanese language, livelihood system, Javanese songs, traditional music instruments, and folktales.Keywords: local wisdom learning, early childhood student, full day early childhood school
Especies reactivas de oxígeno y la enzima Superóxido Dismutasa como defensa de las plantas al estrés hídrico
Authors: Pulido Pulido Sandra Yamile 
Published: March 2017

<p> El cambio climático a escala global y regional ha influido en la frecuencia e intensidad de fenómenos climáticos extremos como las sequías, incrementado las zonas áridas en el planeta, como consecuencia, los eventos de estrés por sequía han aumentado en las plantas. Esta investigación tiene como objetivo mostrar la habilidad y estrategia de las plantas para responder y adaptarse al estrés por sequía mediante la enzima Superóxido Dismutasa (SOD). Se encontró que las respuestas bioquímicas se constituyen en uno de los principales mecanismos de defensa contra este tipo de estrés, uno de estos mecanismos es la sobreproducciónde especies reactivas de oxígeno (ROS) el cual es controlado por sistemas antioxidantes. Dentro de estos sistemas antioxidantes se encuentra la enzima antioxidante Superóxido Dismutasa (SOD). Se concluye que las defensas antioxidantes isoformas de la enzima Superóxido Dismutasa (Mn-SOD, Cu/Zn-SOD, Fe-SOD), se hallan en diferentes especies vegetales y funcionan como eficientes detoxificadores de ROS. Por esto pueden ser una herramienta valiosa en los programas de mejoramiento genético de plantas buscando aumentar la tolerancia de éstas al déficit hídrico.</p>
FRONTLINE: An innovative direction in academic journalism
Authors: Bacon Wendy 
Published: March 2017

The Pacific Media Centre—Te Amokura—which publishes Pacific Journalism Review has always been concerned to link ‘robust and informed journalism’ with media research that contributes to social development both in the broader community, the media industries and inside the academy. The new section Frontline aims to further this by addressing more directly the interface between professional or practice-based journalism and scholarly journalism research practices. This commentary reflects new directions in academic journalism. It is worth charting some of the developments that have brought us to this point.
Font Attributes based Text Steganographic algorithm (FATS) for communicating images: A nuclear power plant perspective
Authors: Krishnan R. B. , Thandra P. K. , Murty S. A. V. Satya , Thiyagarajan P. 
Published: March 2017

Abstract
Today even sensitive organizations like nuclear power plants are connected to the internet. As information security is of utmost priority to such organizations, achieving the same is a challenging task while using the public network like the internet. Though cryptography could be used to enhance the information security, it cannot hide its own presence from the attackers. This drawback lead security professionals to look for an alternate technique like steganography. Steganography hides the secret information, stealthily, inside another innocent looking cover medium like text, image, audio and video. Considering these, this paper proposes a novel text steganographic algorithm that embeds images as codes in the font attributes such as color, character spacing and kerning. The procedure of representing an image as codes makes the proposed method independent from the resolution of the image. Experiments were conducted by embedding diverse categories of images. A comparison with the best existing method depicted that the embedding capacity attained by the proposed method is higher at 1.59-bits/character, which suits best for low bandwidth environments. Various security aspects of the proposed method have also been discussed.
Trends in the diagnosis and management of hypertension: repeated primary care survey in South West England
Authors: Mejzner Natasha , Clark Christopher E , Smith Lindsay FP , Campbell John L 
Published: March 2017

BackgroundPrevious surveys identified a shift to nurse-led care in hypertension in 2010. In 2011 the National Institute for Health and Care Excellence (NICE) recommended ambulatory (ABPM) or home (HBPM) blood pressure (BP) monitoring for diagnosis of hypertension.AimTo survey the organisation of hypertension care in 2016 to identify changes, and to assess uptake of NICE diagnostic guidelines.Design and settingQuestionnaires were distributed to all 305 general practices in South West England.MethodResponses were compared with previous rounds (2007 and 2010). Data from the 2015 Quality and Outcomes Framework (QOF) were used to compare responders with non-responders, and to explore associations of care organisation with QOF achievement.ResultsOne-hundred-and-seventeen practices (38%) responded. Responders had larger list sizes and greater achievement of the QOF target BP ≤150/90 mmHg. Healthcare assistants (HCAs) now monitor BP in 70% of practices, compared with 37% in 2010 and 19% in 2007 (P<0.001). Nurse prescribers alter BP medication in 26% of practices (11% in 2010, none in 2007;P<0.001). Of the practices, 89% have access to ABPM, but only 71% report confidence in interpreting results. Also, 87% offer HBPM, with 93% of these confident in interpreting results.ConclusionIn primary care BP monitoring has devolved from GPs and nurses to HCAs. One in 10 practices are not implementing NICE guidelines on ABPM and HBPM for diagnosis of hypertension. Most practices express confidence interpreting HBPM results but less so with ABPM. The need for education and quality assurance for allied health professionals is highlighted, and for training in ABPM interpretation for GPs.
Fontaine de Vaucluse : Compte-rendu hydrogéologique de l'opération Spélénaute du 2 août 1985
Authors: Bayle Bernard , Graillot Didier ,   Société Spéléologique de Fontaine de Vaucluse
Published: March 2017

The «spelenaut operation» at the Fontaine de Vaucluse (August 1985)
During August 1985, while the water level was low, the Fontaine de Vaucluse was explored down to 315 m. Examination of the recorded video tape shows that the «Spelenaut» reached a sandy ledge at the entrance of what appears to be a continuation of the submerged gallery. The aspect of the limestone is varied and it is difficult to determine geological from erosive phenomena. Analysis of the samples collected by the machine illustrates the need for similar explorations in order to obtain further informations concerning the geology of drainage basin.