bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pengembangan LKPD Digital Berorientasi Nature of Science dan Berbantuan PhET Interactive Simulation pada Materi Gerak Harmonik Sederhana
Authors: Mahendra Zhenk Eka , Purwana Unang , Liliawati Winny 
Published: March 2023

Penelitian ini bertujuan untuk mengembangkan dan menganalisis kelayakan LKPD digital berorientasi nature of science dan berbantuan PhET Interactive Simulation. Penelitian ini menggunakan metode penelitian dan pengembangan dengan model ADDIE. Partisipan penelitian ini terdiri dari 4 orang validator dan 32 peserta didik kelas X SMA. Instrumen yang digunakan dalam penelitian ini berupa lembar validasi LKPD, lembar wawancara semi terstruktur, dan angket respon peserta didik. Berdasarkan data hasil validasi LKPD didapatkan indeks validitas Aiken sebesar 0,83 dengan kategori validitas tinggi. Respon yang diberikan peserta didik sangat positif dengan rata-rata persentase hasil respon sebesar 87,31%. Penilaian LKPD digital mendapatkan hasil rata-rata nilai sebesar 85,85 yang termasuk ke dalam kategori baik. Dengan demikian, LKPD digital berorientasi nature of science dan berbantuan PhET Interactive Simulation pada materi gerak harmonik sederhana sangat layak untuk digunakan dalam pembelajaran dan dapat digunakan sebagai sumber belajar mandiri oleh peserta didik. This study aims to develop and determine the feasibility of the nature of science-oriented digital student worksheets and is assisted by PhET Interactive Simulation. This study uses research and development methods with the ADDIE model. The subjects of this study consisted of 4 validators and 32 students of class X senior high school. The instruments used in this study were student worksheets, validation sheets, semi-structured interview sheets, and student response questionnaires. Based on the student worksheets validation results data, Aiken’s validation index is 0.83, with a high validity category. The responses given by students were very positive, with an average percentage of response results of 87,31%. The digital student worksheets assessment got an average score of 85.85, which included a good category. Thus, digital worksheets oriented to the nature of science and assisted by PhET Interactive Simulation on simple harmonic motion material are very suitable for learning and can be used as a source of independent learning by students.
Mural Removals During COVID-19 Pandemic: Violation of Freedom of Expression?
Authors: Paramita Aulia , Phalevy Rifqi Ridlo 
Published: March 2023

This COVID-19 pandemic has caused a decline in the community's economy, leading the government to issue policies that are deemed unsatisfactory by the people. As a result, it has spurred artists to create murals containing criticism of the government. However, the public perceives the government to be against criticism because they have removed murals, which is deemed to have violated local regulations and forgotten that everyone has the right to freedom of expression. This study aims to analyze the implementation of the Pasuruan City Regional Regulation No. 2 of 2017 Article 19 Letter a and assess the compatibility of the regulation with Law No. 39 of 1999 concerning Human Rights. The research method used is socio-legal method, and the results of this study indicate that the removal of murals was not based on human rights. Therefore, this study concludes that there should be a special treatment for murals with critical content.
Highlights :

COVID-19 pandemic has led to a decline in the community's economy, which has resulted in the government issuing unsatisfactory policies.
Murals have been created by artists to criticize the government, but the removal of these murals by the government has sparked public outrage.
The study found that the removal of murals violated human rights, and therefore, there should be a special treatment for murals with critical content.

Keywords: Mural removals, COVID-19 pandemic, Freedom of expression, Government policies, Human rights.
Always a White Christmas in the Bahamas: temperature and hydrodynamics localize winter mud production on Great Bahama Bank
Authors: Purkis Sam J. , Oehlert Amanda M. , Dobbelaere Thomas , Hanert Emmanuel , Harris Paul (Mitch) 
Published: March 2023

ABSTRACTWhitings, or occurrences of fine-grained carbonate in the water column, have been observed in modern environments with salinities ranging from fresh to marine conditions, and thick deposits of lime mud are described throughout the geological record. Despite their ubiquity, the trigger for whitings has been debated for more than eighty years. Satellite data reveal that most whitings are restricted to the northwestern part of Great Bahama Bank (GBB) which occupies &lt; 10% of the platform area. Even here, whitings are further focused. More than 35% of them occur in a zone which occupies just 1% of the platform. We propose a three-step process for the existence of this zone of peak whitings and why the whitings in it are both more frequent and larger in winter than summer. First, the temperature differential between on- and off-platform waters is highest in the winter, setting up a disparity between dissolved CO2 concentrations in the two water masses. Second, hydrodynamic mixing of these two water masses increases the degree of aragonite saturation of the platform-top waters, as colder on-platform waters with theoretically higher concentrations of dissolved gases are warmed via mixing with the warmer off-platform waters. Finally, spatial heterogeneity in the degree of aragonite saturation is higher in the winter, and the zone of peak whitings is situated in an area of locally enhanced saturation state. Hydrodynamic simulation suggests that the whitings zone is located by tidal inflow of off-platform waters across the western margin of GBB, as well as inflow from the Tongue of the Ocean to the north of Andros Island. Despite thermodynamic forcing mechanisms that predict higher frequency of whitings in the summer, the environmental, hydrodynamic, geochemical, and kinetic conditions in the whitings zone appear to support the Goldilocks configuration that enhances the formation of wintertime whitings on Great Bahama Bank. This phenomenon has implications for the interpretation of whitings mud in the geological record, including the geochemical signatures within it.
Vaca Muerta: Integrated Characterization of Natural Fractures and Oil Wettability Using Cores, Micro-Resistivity Images and Outcrops for Optimizing Landing Zones of Horizontal Wells
Authors: Abd Karim Rahimah , Aguilera Roberto , Vittore Franco Juan , Rincon Maria Florencia 
Published: March 2023

AbstractUnderstanding natural fracture width distribution, and pore sizes relation to thermal maturity, permeability and wettability is important in assessing shale reservoir quality and determining the productive landing zones for horizontal wells. Natural fractures and pore systems in Vaca Muerta are complex with significant lateral and vertical variations. This study provides an integrated characterization using cores, micro-resistivity images and outcrops that reveal the vertical variability of natural fractures and oil-wet characteristics of Vaca Muerta shale.The proposed method describes first the distribution of fracture widths from cores, micro-resistivity images and outcrops using a Variable Shape Distribution (VSD) model. The VSD provides a good fit of the data, which improves fracture width and intensity prediction. Subsequently, porosity, Total Organic Carbon (TOC) and water saturation (Sw) are modeled and calibrated with core data. Values of the porosity exponent m and the water saturation exponent n reflect the complexity of the pore system and wettability characteristics of Vaca Muerta. The method also incorporates for the first time, thin bed heterogeneity that comprises calcite beef, ash beds and nodules.Results indicate that fracture widths at Vaca Muerta range between 0.0003 and 2 mm for cores, 0.01 and 2 mm for micro-resistivity images, and 0.0003 and 7 mm for outcrops. The VSD captures the entire distribution of cores, images and outcrops, which allow pragmatic fracture width extrapolation. The physical widths can also be used to generate synthetic production logs (PLT) that indicate relative productivity from fractured intervals. The study reveals that better reservoir quality lies in the deeper organic-rich units of the Lower Vaca Muerta (LVM) shale. The LVM has lower Sw, larger pores, higher TOC, and greater natural fracture intensity. Pickett plots indicate decreasing m and increasing n values with depth. This suggests increasing natural fractures intensity and oil wettability towards the LVM, which is corroborated by cuttings descriptions, micro-resistivity images and a published Scanning Electron Microscopy (SEM) study. All these findings support the relation between pore sizes and thermal maturity, permeability and wettability. Finally, the study highlights the importance of incorporating thin bed heterogeneity in the analysis, due to its high occurrence in the organic-rich unit.The integrated analysis using cores, micro-resistivity images and outcrops reveals the variability of natural fracture intensity and oil-wet characteristics in each stratigraphic unit of the Vaca Muerta shale. The analysis considers, for the first time, the internal anatomy of thin bed heterogeneity. This methodology proves powerful for understanding the complex Vaca Muerta shale and for optimizing the landing zones of horizontal wells.
Reconciliation and Insights from a Holistic Reservoir Characterisation Program in a Late, Early-Oil to Early, Peak-Oil Window Shale Oil Play - Eromanga Basin, Australia
Authors: Richards Brenton , Solano Nisael , Baruch Elizabeth , Gordon John , Younis Adnan , DeBuhr Chris , Ghanizadeh Amin , Stasiuk Lavern , Bein Cassandra , Mitchell Brendon , Clarkson Christopher R. , Pedersen Per 
Published: March 2023

AbstractThe objective of this work was to develop and apply integrated geological and experimental workflows to enable a holistic evaluation of the reservoir quality and potential producibility of a prospective shale oil play - the Toolebuc Formation (Eromanga Basin), Australia. Tight oil reservoirs are notoriously difficult to characterize; routine analytical and experimental methods developed for tight reservoir characterisation are prone to providing contradicting observations depending on the complexity of the reservoir. This paper explores the data collection methods and results from a calcareous, organic-rich shale and demonstrates the benefits of combing multiple analytical techniques in the early stages of resource appraisal.The Toolebuc Formation is within a late early oil to early peak oil window at the key well sites which, provide access to the most thermogenically mature material recovered for testing in the play to date. Routine shale core analysis data indicate significant gas-filled porosity, which is inconsistent with the anticipated fluid profiles for the optically determined thermal maturity window. Isotopic data collected on mud gas during drilling indicate biogenic signatures within the light-end hydrocarbon fractions; however, this isotopic signature was not present in the headspace gas of low-temperature hydrous pyrolysis (LTHP) experiments. These observations raise questions regarding the maturation pathway and associated fluid evolution for this source rock reservoir and whether apparent in-situ fluid volatility may enhance the exploitation of this resource in lower thermal maturity windows. This research work provides unique opportunities to advance the fundamental understanding of hydrocarbon generation and production in calcareous organic-rich shales from a prospective Australian Basin, with potential implications for other similar organic-rich shale plays globally.
Characterization of Distributed Acoustic Sensing Signals in Hydraulic Fracturing Stimulation - A Coupled Flow-Geomechanical Simulation Approach
Authors: Chen Jiahui , Leung Juliana Y. , van der Baan Mirko 
Published: March 2023

AbstractLow-frequency distributed acoustic sensing (LF-DAS) is one of the promising diagnostic techniques to detect and characterize hydraulic fractures. LF-DAS signals can capture fracture hits and the strain field around the hydraulic fracture. However, the interpretation of field LF-DAS data and the relationship between fluid allocation and production can be challenging due to the complexity of the underground conditions. This study develops a fracture propagation model to simulate the hydraulic fracturing process. The modelling results are analyzed to examine patterns and trends observed in actual field DAS data.The fracture propagation model, coupled with the flow and geomechanical computations, is implemented in the MATLAB Reservoir Simulation Toolbox (MRST). The flow and geomechanical calculations are discretized by the finite volume and virtual element methods, respectively. The hydraulic fracture is set to propagate along a prescribed path with a specified propagation or activation criterion. The accuracy of our model is validated against the KGD analytical solutions for the leak-off-viscosity and storage-viscosity dominated regimes.The simulated stress and strain features are consistent with those interpreted from field DAS signals. Several case studies are presented to demonstrate the modelling approach's utility and examine fracture interference, closure, and stress shadowing effects. The modelling work facilitates interpreting field measurement data by investigating characteristics of fracture hits from adjacent wells. The modelling method provides insights into fracture interference and its implications on optimal designs during hydraulic fracturing stimulation.
An Integrated Geology-Engineering Approach to Duvernay Shale Gas Development: From Geological Modeling to Reservoir Simulation
Authors: Hui Gang , Chen Zhangxin , Wang Hai , Wang Muming , Gu Fei 
Published: March 2023

AbstractUnconventional shale resources are widely distributed in the Western Canadian Sedimentary Basin and have great potential for development. However, due to the complex distribution of shale sweet spots and the high drilling and fracturing costs of horizontal wells, the petroleum industry faces great challenges in the efficient and economic development of shale resources. This paper proposes an integrated geological-engineering method to characterize the Duvernay shale reservoir near the Fox Creek region. First, reservoir petrophysics is characterized based on core experiments. Second, based on geomechanical experiments and acoustic logging, we characterize elastic parameters and in-situ stress tensors to establish a geomechanical model. Next, focal mechanisms of microseismicity are employed to identify large-scale natural fractures and faults. Then, based on the aforementioned models, as well as the perforation and treatment data, the propagation of full 3D hydraulic fracture networks for horizontal wells is simulated to construct the unconventional fracture model (UFM) via Petrel Kinetix. Finally, numerical simulations of horizontal wells are conducted, which are further corroborated by the production performance of fractured wells. It is found that the core analysis of the key well suggests that reservoir porosity, permeability, and gas saturation are averaged to be 5.3% and 404 nD, respectively. The rock mechanical parameters, including Poisson's ratio, and Young's modulus, are derived from the triaxial compression tests, with both average values of 0.21 and 36.2 GPa, respectively. The natural fractures in the examined region have been demonstrated to be governed by two-period tectonic activities and hence developed with mean dip azimuths of NE21° and SE111°, respectively. Real-time fracturing parameters of four horizontal wells are used to simulate the complex propagation of hydraulic fracture networks, considering the reservoir heterogeneity and stress shadows among different stages. Numerical simulations of well production are conducted based on the geological and geomechanical models. The agreement between simulation results and production performance reaches more than 90%, indicating the effectiveness of this integrated method for shale gas development. This work provides a solid foundation for site selection and fracturing job size optimization of new horizontal wells in the future.
Proactive Prevention of Ferromagnetic Iron-Induced RSS Tool Failures Using Novel Testing Techniques and Operational Modifications.
Authors: Hadley Dylan , Watts Luke , Russell Ryan , Okesanya Temi , Heath Garett 
Published: March 2023

AbstractThe ubiquity of complicated and extended-reach horizontal wellbores with tighter windows has spurred the copious use of the rotary steerable system (RSS) in drilling operations. This magnetic-powered RSS technology, initially designed for the offshore drilling market, has proven to be an effective solution to the increasingly complex challenges in the land-based market. Although durable, as with other mechanical devices, equipment failure and malfunction may occur during drilling operations. The impairments of these expensive high-end systems while drilling often lead to costly trips and NPTs, which can be avoided with regular maintenance practices. Apart from these regular maintenance practices, it is also paramount to devise proactive techniques while drilling that will enhance the life cycle of these systems and prevent rampant and uneconomical trips.This paper presents a proven methodology that was used to eliminate the rampant RSS tool failures encountered on multiple rigs in Southern Alberta, Canada. While RSS tool failures have traditionally been attributed to the barite and mud system, scientific root cause analysis showed that ferromagnetic iron metal generated from different sources while drilling induced these failures. Ferromagnetic Iron has the potential to cause interference with downhole magnetic tools, causing them to fail and have solids entrapped in them.An ingenious operational procedure was devised and implemented using strategically generated magnetic fields in the mud circulation system at different locations. These magnetic fields strip the mud system of ferromagnetic materials to prevent damage to RSS tools. This procedure was also backed up with a novel testing technique that identifies and quantifies the presence of ferromagnetic materials in the mud system, which can be tracked on the daily drilling report or posted on a digital database. The test results help engineers detect the buildup of ferromagnetic iron in the mud system (indicating the strength of the magnetic fields) and the appropriate mitigation strategy to employ, which may include strengthening the magnetic fields and using centrifuges depending on the scenario.This successful approach eliminated RSS tool failures on multiple rigs and reduced Tool-Failure NPTs drastically by over 47% on average. This paper breaks down, showcases, and elucidates a practical engineering solution to a prevalent drilling problem, with easy-to-follow steps that can be replicated by mud engineers and technicians anywhere in the world.
Field-Scale Modeling of Interwell Tracer Flow Behaviour to Characterize Complex Fracture Networks Based on the Embedded Discrete Fracture Model in a Naturally Fractured Reservoir
Authors: Liu Jinju , Jiang Liwu , Liu Tongjing , Yang Daoyong 
Published: March 2023

AbstractIn this study, the newly proposed numerical models have been verified and used to characterize the fracture distributions in a naturally fractured reservoir conditioned to tracer transport behaviour. The stochastic fracture modeling approach is implemented to generate the randomly-distributed natural fractures which are dealt with the embedded discrete fracture model (EDFM) while ensuring its sufficient accuracy. To be specific, the matrix domain is discretized using the structured grids, within which each embedded fracture is divided into a series of segments. Subsequently, non-neighbouring connections allow us to couple the flow of fluid and tracer between the non-neighbouring grid cells, while the historical tracer profiles are matched to delineate the geometry and properties of the fractures by taking multiple tracer transport mechanisms into account. Furthermore, the influences of fracture number, fracture length, fracture orientation, and tracer dispersion on the tracer production concentration have been investigated through sensitivity analysis. The response of an interwell tracer model is sensitive to the fracture parameters rather than tracer properties. A fracture network with its orientation parallel to the mainstream direction will cause the earliest tracer breakthrough. The tracer breakthrough time with an average fracture length equal to 40 m is 110 days earlier than that with a mean fracture length value of 10 m, while the tracer production peak concentration for the former is nearly two times higher than for the latter. A larger fracture number results in an earlier tracer breakthrough and an intermediate fracture number will lead to the highest tracer production concentration. Additionally, the newly developed model has been validated through its comparison with the commercial ECLIPSE simulator and then extended to field applications to identify the possible fracture distributions by simulating multi-well tracer tests in the Midale field. The flexible and pragmatic EDFM-based method developed in this study can model the interwell tracer flow behaviour as well as characterize the properties and geometries of the natural fractures with better performance on accuracy and calculation efficiency in comparison with other fracture simulation methods (e.g., local grid refinement (LGR) method).
A Comparative Study Between Artificial Intelligence Models and a Statistical Learning Model to Predict Gas Adsorption in Shales
Authors: Aly Moustafa , Abdulraheem Abdulazeez , Moawad Taha 
Published: March 2023

AbstractAs a cleaner energy source, the importance of shale gas as a fuel has increased in the past few decades with the main challenge faced being its quantification. While many accurate models exist for the estimation of the free gas inside the pore space of shales, only a limited number of empirical models with insufficient accuracy exist that can quantify the adsorbed gas. Also, adsorption experiments are complicated, time consuming, and prone to many sources of error including gas leakage during coring and preparation of samples. An attempt was made to develop a computational model to predict shale gas adsorption using statistical learning with a large data set consisting of 301 entries. The work done in this study attempted to develop artificial intelligence (AI) models that outperform the existing statistical learning model using the same data set. Three AI techniques were utilized in this study namely artificial neural networks (ANN), adaptive network-based fuzzy logic (ANFIS), and functional networks (FN). Using each AI technique, a submodel was developed for the prediction of both the Langmuir pressure and volume. The Langmuir pressure submodel used temperature (T), total organic carbon (TOC), and vitrinite reflectance (Ro) as input variables while only T and TOC were used as input for the volume submodel. Results showed that a model developed using ANFIS for the prediction of Langmuir pressure had an average absolute percentage error of only 15.26% compared to 27.67% of the statistical learning model. As for the volume submodel, ANN produced the best results with an AAPE of 21.34% compared to the original 23.76%. While FN showed better results in pressure prediction compared to statistical learning, the opposite was true for volume prediction. Also, in both prediction models (pressure and volume), FN was the least accurate our of the three AI methods.