The Discovery tool is a growing organism Bardelli, Annalisa; Verga, Francesca
JLIS.it : Italian journal of library and information science,
01/2019, Volume:
10, Issue:
3
Journal Article
Peer reviewed
Open access
This article sums up two years of work selecting, configuring and promoting a discovery tool. Our choices were based on our circumstances and might not be right for every library. However, they led ...us to a state of things which we find satisfactory, and which we are going to improve further. That is why we wish to share them with colleagues who face the same challenges daily, hoping our experience can be of help.
The Po Plain in northern Italy is one of the most populated and industrialized European regions and hosts numerous gas fields, which have been in production for decades. Several reservoirs were ...subsequently converted into underground storage sites for natural gas (UGS) while others are currently candidates for future storage of CO2 or H2. In all cases, the reservoir caprock confining the fluids underground is the Argille del Santerno formation. The Argille del Santerno is a good-quality shale; it has a thickness ranging from several tens to hundreds of meters and it extends across a large part of the subsurface of the Po Plain. The part of the formation that acts as a caprock for the main reservoirs lies at an average depth of 1200–1500 m.
The scope of the present work was to obtain a sound evaluation of Young's modulus of the Argille del Santerno based on experimental data so as to describe the deformation behavior of the formation at current or prospective storage sites. To this end, we collected and analyzed a wide range of data from triaxial tests, ultrasonic laboratory analysis, and well logs from 6 different locations (corresponding to 6 reservoirs) in the Po Plain. Our dataset was enriched by publicly available log data, which we used for stratigraphic correlation purposes and identification of the Argille del Santerno throughout the Po Plain. An empirical relation between Young's modulus from log data and depth was inferred. Discrepancies among the results of the analyses are presented and discussed. We investigated the effects of alteration of cementation, diagenetic and aging behavior due to sampling operations, and the impact of the investigation techniques at the specimen scale (triaxial test and sonic wave propagation data) on Young's modulus values. This was done to explain the differences between lab and well values.
This paper provides a unique characterization of the Young's modulus of the Argille del Santerno at a regional scale, to serve as a reference for reliably predicting ground-level movements induced by underground storage activities.
•Integrated analysis of Santerno shales deformational behaviour from lab and well data.•Empirical relation of dynamic Young's modulus with depth at wellbore scale.•Correlation between static and dynamic Young's modulus.•Quantification of diagenesis effects from mineralogical analysis.•Santerno shales exhibit well predictable deformation behaviour at regional scale.
Depleted gas reservoirs are a valuable option for underground hydrogen storage (UHS). However, different classes of microorganisms, which are capable of using free H2 as a reducing agent for their ...metabolism, inhabit deep underground formations and can potentially affect the storage. This study integrates metagenomics based on Illumina‐NGS sequencing of bacterial and archaeal 16S rRNA and dsrB and mcrA functional genes to unveil the composition and the variability of indigenous microbial populations of four Italian depleted reservoirs. The obtained mcrA sequences allow us to implement the existing taxonomic database for mcrA gene sequences with newly classified sequences obtained from the Italian gas reservoirs. Moreover, the KEGG and COG predictive functional annotation was used to highlight the metabolic pathways potentially associated with hydrogenotrophic metabolisms. The analyses revealed the specificity of each reservoir microbial community, and taxonomic and functional data highlighted the presence of an enriched number of taxa, whose activity depends on both reservoir hydrochemical composition and nutrient availability, of potential relevance in the context of UHS. This study is the very first to address the profiling of the microbial population and allowed us to perform a preliminary assessment of UHS feasibility in Italy.
Depleted gas reservoirs are a promising underground hydrogen storage (UHS) option. This study is the first microbiological characterization of four Italian depleted reservoirs in the perspective of UHS. Our approach integrates hydrochemical analysis and metagenomic characterization, based on 16S rRNA and functional genes, with predictive functional annotation, to critically evaluate the occurrence of microorganisms capable of using hydrogen or affecting UHS.
Over the last years great efforts have been made within the University environment to implement e-learning technologies in the standard educational practice. These learning technologies distribute ...online educational multimedia contents through technological platforms. Even though specific e-learning tools for technical disciplines were already available on the Internet, in our opinion more general tools, typically involving calculations, plots or diagrams, through the use of spreadsheets or graphical applications, were still needed to provide a more flexible and multi-purpose integrated environment. Therefore, we developed an integrated system to supply e-learning platforms with almost the same functionalities offered by standalone Office Automation applications. Modular object-oriented dynamic learning environment (MOODLE) and OpenOffice.org were selected to deal with any problem originating from the software and to smooth over the users' learning curve. Furthermore, MOODLE is a modular platform and offers an extensive application programming interface for coding in a simple and effective manner. The implementation of the work required the employment of Java and Asynchronous JavaScript and Extensible Markup Language technologies and included the creation of a Java Applet to be embedded in the web pages of the new MOODLE modules. Students could thus be offered a single working environment for handling "traditional" material and performing practical activities. The students' feedback on this new integrated system was very positive and proved the effectiveness of our work.
During reservoir characterization all the geological uncertainties affecting the quantity and distribution of hydrocarbons should be captured to assess the risks affecting final recovery.
In a ...typical modeling workflow the geological uncertainties are accounted for through the construction of a sufficiently large set of 3-D static models. Out of this set, a few representative models are selected and dynamically simulated so as to correlate the geological characteristics of the reservoir with its dynamic performance and to propagate the uncertainty onto the final recovery factors, yet maintaining the computational run time acceptable. In channelized depositional environments, which are strongly heterogeneous, the selection approach must also account for channel connectivity, which plays a key role in the possibility of efficiently draining the reservoir for a reasonable number of wells.
This study can be seen as a step forward in the assessment of the risks associated to the development of channelized reservoirs under the assumption that a way to express the concept of channel connectivity is channel amalgamation. Channel amalgamation is here defined through amalgamation curves which are numerically described using a set of indexes whose combination provide spatial information of channel intersections. These indexes were calculated for a full set of 3-D geological models and used to steer the selection of a representative model sub-set for subsequent fluid flow simulations.
The validity of the index-based selection was verified on different sets of synthetic reservoir models through the evaluation of the representativeness of the model sub-set in reproducing the uncertainty of the original dataset. Eventually, the existence of a strong correlation between channel amalgamation and production performance was proved. From a practical perspective, the possibility to include channel amalgamation in the assessment of the geological models can considerably improve the representativeness of the selected models for uncertainty propagation thus reducing significantly the number of geological models to be considered.
•Channel amalgamation is defined through novel numerical indexes.•Channel amalgamation allows uncertainty propagation to future reservoir production.•Amalgamation indexes can be used to rank channelized reservoir models.•Representative geological models can be selected based on amalgamation indexes.
The multi-disciplinary work described in the paper was aimed at analyzing and predicting the cyclical ground surface movements induced by underground gas storage (UGS) activities in a depleted gas ...field located in the Po Plain (Italy). The field has been operated as a storage facility for nearly three decades. Currently, the possibility of delta-pressuring the reservoir (i.e. to increase the maximum operating pressure above the initial reservoir pressure) to enhance the storage performance is being considered. Significant information was collected over time: 2/3D seismic surveys, geological and sedimentological studies, 60+ logged wells, geotechnical lab tests and 50+ years of production history and monitoring were available for the development of a fully integrated static–dynamic–geomechanical analysis. The mechanical aspects of the study are the focus of this paper. The data coming from different sources at different scales were analysed and integrated to set up and characterize a 3D finite element method mechanical model to calculate the surface movements induced by UGS activity by adopting an elasto-plastic constitutive law. The model was then calibrated via a back analysis approach, i.e. the model parameters were fine-tuned so that the simulated subsidence/uplift would compare satisfactorily with the ground movements collected over nearly 10 years of monitoring via interferometric synthetic aperture radar analysis in the region under investigation. Eventually, the calibrated model was used as a forecasting tool for subsidence evaluation under different future storage strategies, including delta-pressuring conditions. Results proved that no significant subsidence is expected even if the maximum operating pressure reached 120 % of the initial formation pressure.
Harmonic Pulse Testing (HPT) has been developed as a type of well testing applicable during ongoing field operations because a pulsed signal is superimposed on background pressure trend. Its purpose ...is to determine well and formation parameters such as wellbore storage, skin, permeability, and boundaries within the investigated volume. Compared to conventional well testing, HPT requires more time to investigate the same reservoir volume. The advantage is that it does not require the interruption of well and reservoir injection/production before and/or during the test because it allows the extraction of an interpretable periodic signal from measured pressure potentially affected by interference. This makes it an ideal monitoring tool. Interpretation is streamlined through diagnostic plots mimicking conventional well test interpretation methods. To this end, analytical solutions in the frequency domain are available. The methodology was applied to monitor stimulation operations performed at an Enhanced Geothermal System site in Pohang, Korea. The activities were divided into two steps: first, a preliminary sequence of tests, injection/fall‐off, and two HPTs, characterized by low injection rates and dedicated to estimate permeability prior to stimulation operations, and then stimulation sequence characterized by a higher injection rate. During the stimulation operations other HPT were performed to monitor formation properties behavior. The interpretation of HPT data through the derivative approach implemented in the frequency domain provided reliable results in agreement with the injection test. Moreover, it provided an estimation of hydraulic properties without cessation of stimulation operations, thus confirming the effectiveness of HPT application for monitoring purposes.
Key Points
An advanced methodology for well performance monitoring without production interruption is presented
Diagnostic plots analogous to oil industry conventional well testing for flow geometry and regime identification were adopted
A field case validation shows the successful application of the methodology to monitor the stimulation of a well of an enhanced geothermal system
Functionalization of graphene with dimethyl acetylenedicarboxylate is achieved through a microwave-assisted Diels-Alder reaction. The physical, chemical, and electrochemical properties of the ...modified sheets are thoroughly investigated by complementary characterization techniques. Density Functional Theory calculations are employed to examine the functionalization mechanism and to highlight the role of defects such as epoxide bridges introduced in graphene during exfoliation. Our findings provide valuable insights into the development of efficient and cost-effective methods for large-scale production of high-quality graphene-based materials. Specifically, the electrochemical properties of anode materials containing functionalized graphene are evaluated for Li-ion electrochemical energy storage devices, demonstrating excellent electrochemical reversibility and rate capability. The cyclic voltammetry analysis reveals material stabilization after a few cycles, resulting in a coulombic efficiency of up to 95 % and a discharge capacity of 162.3 mA·h·g−1. The galvanostatic cycling test indicates that the material electrode retains 57 % of its initial capacity at a C-rate of 10C, indicating high-power capability. These promising results position organic modified graphene as a potential material for Li-ion capacitors, with a specific capacity that aligns with the last intercalation stage capacity at a lower potential. Overall, the study's findings offer significant contributions to the advancement of graphene-based materials in energy storage applications.
Display omitted
•Graphene functionalized via microwave-assisted Diels-Alder with DMAD•Modified graphene is characterized by physical and electrochemical properties.•Defects explored using Density Functional Theory (DFT) calculations•Insights into large-scale production of quality graphene materials shared•Graphene as potential anode for high-power Li-ion capacitors highlighted
Stratigraphic forward modelling (SFM) provides the means to produce geologically coherent and realistic models. In this paper, we demonstrate the possibility of matching lithological variability ...simulated with a basin-scale advection-diffusion SFM to a data-rich real-world setting, i.e. the Holocene Rhine-Meuse fluvio-deltaic system in the Netherlands. SFM model calibration to real-world data in general has proven non-trivial. This study focuses on a novel inversion process constrained by the top surface and the sand proportion observed at specific pseudo-wells in the study area. Goodness-of-fit expressed by a new fitness function gives the error calculated as the average of two calibration constraints. Computational efficiency was increased significantly by implementing a new optimization process in two hierarchical steps: a) optimization in terms of sediment load and discharge, which are the most influential parameters having the largest uncertainty and b) optimization with respect to the remaining uncertain parameters, these being sediment transport parameters. The calibration process described allows for the most optimal combination of achieving acceptable levels of goodness-of-fit, feasible runtimes and multiple (non-unique) solutions to obtain synthetic stratigraphic output best matching real-world datasets.
By removing model realizations which are geologically unrealistic, calibrated SFM models provide a multiscale stratigraphic framework for reconstructing static models of reservoirs which are consistent with the palaeogeographic layout, basin-fill history and external drivers (e.g. sea level, sediment supply). The static reservoir models that are matched with highest certainty therefore contain the highest geological realism and may be used to improve deep subsurface reservoir or aquifer property prediction.
The new methodology was applied to the well-established Holocene Rhine-Meuse dataset, which allows a rigorous testing of the optimization; the calibrated SFM allows investigation of controls of the Holocene development on the sedimentary system.
•Lithological variability from SFM, is matched to the Holocene Rhine-Meuse dataset.•Efficient model calibration is achieved through a two-stage optimization process.•Calibrated SFM outputs allow both testing and improve deep characterization.
PDF
