bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pengaruh Pendekatan Pembelajaran Berdiferensiasi Pada Kurikulum Merdeka Terhadap Kemampuan Pemahaman Matematika Siswa Kelas V Sekolah Dasar Penggerak di Kota Bengkulu
Authors: Agusdianita Neza , Ayudia Vivi , Tarmizi Pebrian 
Published: January 2025

Pendekatan pembelajaran berdiferensiasi sering kali menimbulkan tantangan pada pelaksanaan pembelajaran di kelas dalam upaya pemenuhan kebutuhan belajar yang beragam sesuai dengan kemampuan, apa yang disukai, dan latar belakang. Penelitian ini bertujuan untuk mengetahui pengaruh pendekatan pembelajaran berdiferensiasi pada Kurikulum Merdeka terhadap kemampuan pemahaman matematika siswa kelas V di Sekolah Dasar Penggerak Kota Bengkulu. Penelitian ini menggunakan metode kuantitatif, jenis penelitian eksperimen semu, desain penelitian <em>The Matching Only Pretest Posttest Control Gropup Design.</em> Populasi dalam penelitian ini adalah seluruh kelas V Sekolah Dasar Penggerk di Kota Bengkulu. Sampel dalam penelitian ini adalah siswa kelas VA SDN 09 dan SDN 07 Kota Bengkulu. Teknik pengambilan sampel menggunakan <em>cluster random sampling</em>. Instrumen yang digunakan dalam penelitian ini adalah soal berbentuk uraian yang diberikan melalui <em>pretest</em> dan <em>posttest</em>. Data yang diperoleh kemudian diolah menggunakan analisis statistik deskriptif, analisis uji prasyarat, dan uji hipotesis menggunakan uji-t jenis <em>Independent Samples t-test.</em> Berdasarkan hasil penelitian ini diperoleh t<sub>hitung </sub>(4,584) &gt; t<sub>tabel</sub> (2,002) dengan taraf signifikan 5%. Berdasarkan hasil tersebut maka dapat disimpulkan bahwa H<sub>0</sub> ditolak dan H<sub>a</sub> diterima yang artinya terdapat pengaruh pendekatan pembelajaran berdiferensiasi terhadap kemampuan pemahaman siswa.
Successful Implementation CO2 Assisted Hydraulic Fracturing in a Deep and Low Permeability Sandstone Reservoir: First Case in Colombia
Authors: Reina J. , Zabala R. , Marín J. , Portela J. , Bahamon J. , Orozco S. , Prada A. , Orozco N. , Lozano R. , Torres M. , Kaminszczik S. , Cifuentes H. , Reina C. 
Published: January 2025

Abstract
Gas reservoirs in deep formations, with low pressure and low permeability, present a significant production challenge due to the low conductivity of the rock. The hydraulic fracturing technique has been used historically to increase the flow area available to produce hydrocarbons in this type of reservoir.
Particularly, the case of Piedemonte area in the Llanos basin in Colombia, presents additional challenges for stimulation due to the high capillary pressure required by the water-based fluids to be able to move through the small pore throats, causing restriction for their injection and difficulty to flowback to surface. This causes retention of the liquid phase in the rock matrix and trapping mechanisms that prevent obtaining the full benefit of the stimulation technique.
To address this problem, fracturing fluids assisted/energized with CO2 are usually used, whose benefits are focused on: 1) reducing the volume of water injected and mitigating blockage; 2) mitigate the reservoir filling effect associated with fracturing diagnostic tests; 3) reduce the burst pressure due to the cracking by low temperatures; 4) improve the geometry of the fracture due to the greater efficiency of the CO2 fluid carrying and placing the proppant; 5) capture of CO2 from the refining processes and its integration back into the reservoir to increase stimulation efficiency.
This article presents a compilation of the stages performed for the job, from its planning and design, through the assurance of the stimulation fluids with specialized laboratory tests and finally, its execution and results.
Research was made on similar cases around the world, taking the best practices and recommendations for the work. Next, multiple tests were executed in the laboratory such as rheology with the base fluid seeking to reduce the concentration of the polymer and ensuring its performance under the reservoir conditions. Moreover, a low risk of asphaltene precipitation was identified in the hydrocarbon/ CO2 interaction and displacement tests in a representative core achieving 100% regained permeability.
Finally, in March 2024, the first CO2 -assisted fracturing pilot was executed in Floreña field. The well is currently in the cleaning process and is pending production evaluation. The work not only describes the best practices used, but also aims to establish improvement criteria for future jobs.
Predicting Stage Isolation in the Vaca Muerta Formation Using Surface Pressure Diagnostics
Authors: Verrastro F. , Bonapace J. C. , Rodriguez M. B. , Goñi L. 
Published: January 2025

Abstract
This work presents a workflow applied to 27 wells of the Fortin de Piedra Field in Vaca Muerta that can determine the likelihood of isolation problems during fracture stimulation by analyzing pump-down data and comparing fracturing pressures within the same well, providing a practical method to evaluate zonal isolation without specialized downhole instrumentation.
The approach involves a simple workflow that has been applied to analyze 796 plug-and-perf jobs and 11 plugs from different vendors. It starts by categorizing the pressure morphology of pump down diagnostics (water hammer, isolation confirmation, breakdown pressure) to accurately predict if a given job is likely to exhibit lower-than-expected treating pressures and thus, isolation issues. These were tailored with different options based on the available time to have no impact on the efficiency of the operations. Complementary diagnostics such as step-down rate tests and pre/post frac water hammer analysis was also conducted to corroborate the findings.
By applying this consistent workflow, the authors were able to determine with 81% accuracy whether a given job was likely to exhibit isolation issues. This assessment was made solely based on diagnostic data collected during pump-down operations, without the need for specialized downhole monitoring equipment. A simple calculation for the limited entry designs employed suggests that the most likely source of the difference between expected and real treating pressure during the job must be an increased flow area inside the casing, indicating potential plug failure.
With this method, the authors were able to get an early warning when the proportion of stages with isolation problems became higher than usual. Surface tests carried out on those plugs confirmed these findings. Additionally, parent wells showed higher intensity Fracture Driven Interactions from stages where isolation issues were identified.
This paper presents a cost-effective workflow to evaluate zonal isolation in unconventional wells without the need for advanced downhole diagnostics. By applying this workflow, operators can better select and identify the most suitable plug for their operations, improving effectiveness of fracture stimulation treatments.
Monitoring the Effectiveness of a Bullhead Refrac Using Temporarily Deployed Fiber Optic Cable
Authors: Traweek R. , Rice J. , Gattis T. , Chamberlain C. , Del Zoppo M. , Van Buskirk P. , Dutta P. 
Published: January 2025

Abstract
Bullhead refracturing (refrac) treatments in horizontal wells with multiple entry points historically have been particularly challenging to characterize and interpret during the secondary stimulation. Lateral coverage and success are typically measured after the completion of the refrac. This has limited our industry’s ability to connect surface delivery techniques with subsurface responses on a per well basis. This paper presents a unique low-cost approach to monitoring bullhead refracs using a temporarily deployed fiber optic cable focused on real-time data gathering and immediate feedback.
The well development project presented an opportunity to deploy a temporary (single use disposable) fiber optic cable into a newly drilled, uncompleted child well. Disposable fiber optic cable was deployed successfully to the toe of the new drill, which paralleled a series of parent wells of which two were candidates for refracs (Figure 1). Data gathered in the monitoring program included Distributed Acoustic Sensing (DAS) and Distributed Strain Sensing (DSS). The primary focus of the project was to deploy fiber successfully into the child well and monitor the effectiveness of the refrac treatment of each subsequent parent well as it progressed.
Once in place, DSS data was streamed live allowing for a continuous visual of strain across the full lateral section and spanning the full treatment time period of each well. This allowed for identification of lateral coverage during the pressure sink mitigation (PSM) and bullhead refrac treatment, as well as duration of hydraulic connection to the formation at each point along the lateral. The data gathered and simultaneously displayed, provided instant feedback as to surface execution decisions and subsurface impacts. This approach allowed the key personnel to optimize the completion by identifying the time period of maximum effectiveness to end the treatment at that point, resulting in a savings of material and pump time. Additionally observed fracture-driven interactions from parent well refracs to the child well allowed for further child well treatment analysis once the child well’s primary completion was executed. Within acreage containing simultaneous refrac and new drill programs, this approach can be used to maximize the efficiency of both programs by characterizing the treatment of both depleted and non-depleted reservoir.
The Quest for 100% Isolation During Multi-Stage Stimulations
Authors: Peña Elias , Etzel Ethan , Silva Zachary , Peregoy Nathan , Gosney Josh , Simon Paul 
Published: January 2025

Abstract
Multi-stage stimulation has become a cornerstone of unconventional reservoir development. Enabling enhanced hydrocarbon recovery through precise zonal stimulation and achieving 100% isolation between stages is critical to ensure the success of these operations. Effective isolation prevents cross-flow, ensures even distribution of fracturing fluids, and enhances the effectiveness of proppant placement within targeted zones This results in maximum reservoir contact, minimizes fluid loss, and reduces the risk of premature screen-outs or pressure interference between stages. Furthermore, robust isolation improves well productivity, optimizes resource utilization, and reduces operational costs. The use of frac plugs plays a pivotal role in achieving reliable isolation under varying downhole conditions. This paper will describe the significance of 100% isolation in enhancing stimulation efficiency and discusses challenges associated with achieving it. By highlighting the operational and economic benefits of complete isolation, this study emphasizes isolation as a fundamental requirement for successful multi-stage stimulation in modern oil and gas practices.
Slicing the Onion of Multi-Variate Unconventional Stimulation Optimization
Authors: Pearson C. M. , Fowler G. , Rondon J. 
Published: January 2025

Abstract
The optimization of unconventional oil and gas assets requires simultaneous consideration of fracturing and porous media flow phenomena. Many recent works have demonstrated that a fully coupled fracturing and flow modeling workflow can be used for a variety of applications (McClure et al., 2023; Fowler et al., 2023, Pearson et al., 2022). By coupling fracturing and production physics, solutions implicitly reconcile the impact of fracturing designs on well productivity and resource recovery.
In order to optimize fracturing design for a pad of upcoming wells in their Bakken development, Liberty Resources constructed a coupled model which was calibrated and used in an optimization workflow and documented in URTeC paper 4043244 (Pearson et al, 2024). The presented dataset was calibrated against a five well development program in a 2x1 mile spacing unit – one parent well followed by 4 infill wells drilled after 3-/1/2 years of production.
Single-variate analysis of a non-optimized dataset was shown to be significantly inferior to a multi-variate optimization process to develop a "cloud" or "onion" of datapoints allowing the operator to select an economic optimum that either focused on Discounted Profitability Index (return of capital) or Present Value created.
The scope of this paper is to take the multivariate datasets presented in URTeC 4043244 and to dissect them for the individual single variate components. A genetic-algorithm multi-variate optimization procedure was used on the history matched dataset. The first generation used a space-filling design, sampling all regions of the design parameter space (where each completion/stimulation design variable is a parameter). Subsequent generations goal-seek the optimal objective value based on the results of the prior generation. The overall result of the process is a cloud or "onion" of optimization points as a function of the economic parameter being considered. This paper presents the optimized results as sliced datasets which immediately allows the completions engineer to visualize the dependence of the multivariate optimization on the individual components in the completion design.
Evaluation of Perforation Erosion and Fluid Allocation with Distributed Acoustic Sensing in Multi-Stage Fracture Stimulation
Authors: Hamanaka Yasuyuki , Zhu D. , Hill A. D. , Kerr Eric 
Published: January 2025

Abstract
Limited entry design has been utilized to enhance distribution of fracture fluid and proppant across clusters in multi-stage fracture stimulation for horizontal wells. The concept uses limited perforation diameter/number to generate perforation frictional pressure drop to control fluid distribution through perforations, and the goal is to evenly distribute fracture fluid over all clusters. However, in today's field practice, high injection rate and large volume of proppant injection often lead to severe erosion of the perforations, resulting in reduced perforation friction and lower fracturing efficiency. Distributed Acoustic Sensing (DAS) positioned behind the injection wellbore monitors acoustic vibrations generated by slurry injection at the clusters in real time. This enables monitoring and evaluating of the dynamic changes in perforation size and slurry distribution, as indicated by the decay of the DAS signal.
This paper presents a methodology that qualitatively determines the fluid distribution and perforation size for individual clusters using field DAS data. A correlation between the perforation diameter, flow rate and the induced sound pressure intensity are developed based on Computational Fluid Dynamics (CFD) acoustic simulation results. By integrating the acoustic correlation and the wellbore energy balance equation, slurry distribution and perforation size at clusters are simultaneously calculated at every time step in a multi-cluster stage. This calculation is repeated until the end of the treatment, and the cumulative fluid allocation and the post-fracture perforation size are estimated.
The correlation is applied to a field DAS data set. The estimated eroded diameters are compared with post-fracture perforation images taken by a downhole video camera. The estimated cumulative fluid volumes are compared with the interpretation of Distributed Temperature Sensing (DTS). In both datasets, the overall trends are consistent. Two clusters where the perforations were heavily eroded are identified by the DAS interpretation.
These comparisons and the agreements of the results support the validation of the new acoustic correlation and the new DAS interpretation methodology. The DAS interpretation methodology helps observe the process of perforation erosion and understand its mechanism, leading to an improvement of perforation design.
Far-Field Drainage along Hydraulic Fractures: Insights from Integrated Modeling Studies in the Bakken and Permian Basin
Authors: Singh Ankush , Babazadeh Mohsen , Cipolla Craig , Dhuldhoya Karan , Gandomkar Arjang , Lassek John , Manchanda Ripu , McKimmy Michael , Ramirez-Tamayo Daniel , Safari Reza , Shahri Mojtaba , Smith Steve , McClure Mark 
Published: January 2025

Abstract
In this study, we construct and calibrate simulation models of four field-scale datasets: two from the Bakken, one from the Delaware Basin, and one from the Midland Basin. The datasets include diagnostics such as: offset pressure observation wells, cross-well and injection-well fiber, interference tests, post-frac perforation imaging, and production data. For each dataset, we build a list of ‘key observations’ and then vary model parameters to match each observation. The pressure observation wells and the interference tests provide strong constraint on far-field pressure depletion. The calibrated models provide more confidence in the spatial and temporal evolution of fracture conductivity over time. Key conclusions are: (a) fractures are finite conductivity, exhibiting large and persistent pressure gradient during long-term production, (b) fracture conductivity diminishes with distance from the well, (c) fracture conductivity decreases with pressure drawdown, and also, fracture conductivity decreases as a direct function of time, (d) proppant ‘immobilization’ (or, ‘trapping’) caused by fracture roughness is a key determinant of the propped length, (e) the magnitude of proppant trapping appears to a function of both formation properties and mesh size, (f) more speculatively, the magnitude of proppant trapping may also be related to fluid velocity/rate per cluster, and (g) it is advantageous to perform fracture injection testing to measure the pressure and stress profile above the pay zone, especially in formations where significant pore pressure variability is suspected above the target zone.
AI Enhanced Multi-Physics Imaging for Perforation Erosion Analysis: A Quantum Shift in the Accuracy and Efficiency of Unconventional Well Optimization
Authors: Roberts G. , Saha S. , Moreno S. , Viggen E. M. , Tymons T. 
Published: January 2025

Abstract
This paper demonstrates how the integration of multi-physics downhole imaging with machine learning techniques provides a step-change in perforation erosion analysis. We present a novel approach that improves measurement accuracy, consistency, and turnaround time. We reveal how this benefits the fields of completion design and optimisation of hydraulic fracturing, and how this enables gains in productivity and reduction in cost in the development of unconventional wells.
Downhole data is acquired from an integrated array video and phased array ultrasound sensor system. The video is analysed by a two-stage artificial intelligence process to identify perforations within the well and measure their geometries. High quality optical image results are used to train a third artificial intelligence algorithm that identifies and analyses the same perforation geometries from the corresponding ultrasound dataset.
This approach reveals trends in erosional metal loss induced by proppant flow through perforations. This quantitative evaluation of proppant placement and analysis of its uniformity enables engineers to compare the effectiveness of completion designs and the frac operations.
Through experimental data, real-world case studies, and comparisons with conventional workflows, we demonstrate:
Acceleration of the analysis process through automation Improved data quality and consistency by minimizing human error and subjectivity How the use of the video data, with a resolution ten times greater than the ultrasound sensor, as a ground truth and training parameter has been used to dramatically improve the correlation of the two datasets, creating a highly reliable determination of perforation geometries in the widest possible range of well conditions.
Specific case studies included within the paper are as follows:
The application of downhole video measurements, and the evolution of machine learning-enhanced processing. We chart the speed, accuracy and consistency of results from conventional and machine learning-enhanced processes. The integration of video and ultrasound measurements, the correlation between datasets, and the improvements in data integrity resulting from a multi-physics approach. The application of artificial intelligence to optimise measurements from the ultrasound sensor trained using video measurements, and the improvements in the accuracy and reliability of the resulting dataset.
Analysis techniques have been refined and training algorithms developed using both controlled surface tests and a database of over 100,000 perforation images obtained from hydraulically fractured wells. This paper presents the first publication of this unique three-tier artificial intelligence approach, and the results obtained from its application in the field.
Granitoidal Oil-Bearing Formation
Authors: Koshlyak V. A. 
Published: January 2025

Abstract
At the time being there are known some tens oil and gas fields in magmatic (Libya, United States, Venezuela, Russia, China, Egypt, India, etc.). The oil field Bachho (White Tiger) is confined to a horst-shaped granitoid massif - the basement - with a complex inner structure. The massif is located in the Central High of the Cuulong Basin on the shelf of South Vietnam. At the field there more than one hundred wells have been drilled, most of them are highly productive with oil flow rate up to 1350 t/d. The uniqueness of this field is the fact that the reservoir rocks are "fresh" granitoids not clearly touched by weathering processes; the oil column exceeds the amplitude of the structure; and the presence of hydrocarbon gases in the rock voids indicates to existence of some additional hydrocarbon sources 1.
The rock composition of the basement is represented by differently dated granites, adarnellites, granodiorites, diorites, leucomonzodiorites, monzonites. The transition between the rocks is not always clear enough. Besides, the massif is dissected by numerous dikes of comagmatites of the Oligocene effusive rocks composed of diabases, basalts, trachibasaltic porphyrites which fonned a lava sheet over the basement and in the Oligocene terrigenuos sequence.
Tectonic processes, pneumatogenic mineralization, hydrothermal activities Jed to rock alteration. As a result, there is not only increase of secondary porosity, but also enrichment of granitoids with secondary minerals (kaolinite, zeolite, calcite, chlorite, pyrite etc.) filling in secondary voids or developing over the feldspars.
The increasing number of oil and gas reservoirs discovered in granitoid rocks as well as the regional oil-bearing of granitoids on the self of South Vietnam (the oil fields Dragon, Big Bear, Tamdao, Cuulong etc.) allows to admit a Society of Petroleum Engineers new type of reservoir rock - granitoid rocks - along those of terrigenous and carbonate rocks.