bluuebunny/crossref_metadata_2025_split huggingface dataset:
Grinding of Natural Stone Balls with Planetary Movement of the Tool
Authors: Lugovoi V. P. , Popov R. A. 
Published: February 2025

The article presents a diagram of a modernized machine with planetary movement of the tool for grinding balls of colored stone and test results when processing serpentinite. There are various methods and devices for processing metal balls using abrasive methods used in the production of bearings. These devices simulate the operation of a thrust bearing. One of the tools contains a V-shaped groove, in which the workpieces being processed receive predominantly biaxial rotation. Quantitative criteria for evaluating the ball processing process are productivity, dimensional accuracy, spherical shape and surface roughness. Currently, balls made of non-metallic materials are also used: ceramics, glass, glass ceramics and stones, which differ from steel ones in their physical and mechanical properties, primarily such as fragility and lower strength. This is especially noticeable when processing minerals used in the jewelry industry, which differ in structure, the presence of layering, internal defects, etc. All this makes it necessary to process such materials under conditions different from the conditions for processing steel balls (lower pressure forces, speeds). However, insufficient attention has been paid to issues devoted to methods of processing balls made of fragile materials, including jewelry stones. In many cases, the necessary methods and conditions for processing such materials are determined throughout practice by trial and error. The increasing volume of production of beads for making jewelry from natural stone necessitates comprehensive research and generalization of the results of these studies in order to develop recommendations for their practical use. In this work, we propose a method for processing balls in a device that ensures planetary motion of the balls due to the fact that the disk-shaped tool receives periodic rotation from the friction force that occurs when its side surface touches a table performing planetary motion. As a result, the balls located in the conical sockets of the disk receive accelerated motion and roll along a cycloid trajectory. The additional path that the balls travel in the same time, as well as the change in the ratio of the angles of rotation of the balls around their three axes, create conditions for increasing the productivity and accuracy of processing. The experiments were carried out on a pilot plant when processing workpieces made of serpentinite, which belongs to the group of soft stones. The results of the work showed that the batch processing time for each part grinding ope-ration until dimensional stabilization is achieved does not exceed 30 minutes. The amount of allowance removal and the degree to which the required ball dimensional accuracy and roughness are achieved are determined by the size of the abrasive grain.
Resource Design of Structural Concrete Berthing Structures Based on Tribo-Fatigue Methods
Authors: Leonovich S. N. 
Published: February 2025

An increase in one or another damaging factor leads to a decrease in strength or wear resistance. The interaction of damaging phenomena turns out to be complex. If contact load (friction and wear) is added to cyclic loading or cyclic Abstract. An increase in one or another damaging factor leads to a decrease in strength or wear resistance. The interaction of damaging phenomena turns out to be complex. If contact load (friction and wear) is added to cyclic loading or cyclic freeze-thaw (mechanical fatigue), then the reliability and durability of the system receiving them can either decrease, increase, or remain at the same level. The results depend on the conditions of interaction of damaging phenomena. At the intersection of tribology and mechanics of fatigue fracture in the mid-1980s, thanks to the research of Professor Sosnovsky L.A., tribo-fatigue arose – a science that studies not the mutual influence of individual damaging factors, but a complex combination of various damaging phenomena. As a result of this interaction, a special type of degradation of structural concrete of berthing structures is revealed – complex wear-fatigue damage. The conditions and patterns of such damage to berthing structures are studied by tribo-fatigue. Design of reinforced concrete structures based on limit states is a traditional method. For critical structures of berth structures, resource-based design is advisable. Technical resource is an indicator of durability. This is the operating time of an object, in this case reinforced concrete berth structures, from the start of operation until the onset of the limit state. Sea port facilities on the coast of the Far Eastern seas, a distinctive feature of their operation being the climatic conditions of Sakhalin Island, have been studied. The structures of port facilities are affected by waves. In winter, when the temperature drops to below zero, structures become icy in variable water levels and are affected by floating ice.
New Efficient Drillstring-Wellbore Contact Model Makes Real-Time BHA Directional Estimation Possible
Authors: Wilson J. K. 
Published: February 2025

Abstract
Reliably predicting directional tendencies of downhole drilling assemblies has been an interest of researchers for decades. Initial efforts focused primarily on accuracy in calculation, attempting to account for the various nonlinearities that exist downhole (geometric coupling, wellbore contact, friction, etc.). As bottom-hole assembly (BHA) mechanics models have improved to capture these inherently nonlinear behaviors of the downhole system, focus has naturally shifted to improving calculation efficiency and reducing the time required to obtain results. With the continued adoption of automated technology, a fast and reliable method for performing these calculations is even more critical.
A new directional prediction algorithm is developed, in combination with an efficient drillstring-wellbore contact model, which drastically reduces these calculation times and helps address the challenge of balancing accuracy and efficiency. The algorithm uses a newton iteration approach to estimate the equilibrium curvature that the BHA can achieve at specific operational parameters. Bit-steerability and bit-walk angle are used as calibration variables within the model to account for the bit/formation interface, which prevents the need for specific bit or formation details for accurate modeling. Validation of the new directional estimation method is performed via comparisons to an established nonlinear finite element model (FEM) as well as actual directional performance data from both rotary-steerable systems (RSS) and steerable mud motors.
The resulting modeling algorithm shows a drastic improvement in the calculation time of directional sensitivity analysis, obtaining results in 1-10 seconds for even larger more complicated BHAs, compared to 1-15 minutes using nonlinear finite elements. This comparison also shows a strong agreement between the calculated values of the two modeling methods, establishing confidence that the new approach adequately accounts for the various intricacies and nonlinearities that exist downhole. The reliability of the new directional model is further highlighted via a direct comparison with actual directional performance data.
The use of this new efficient drillstring-wellbore contact model, in combination with a direct integration of drillstring deflections, provides an efficient alternative to calculating the directional behavior of BHAs in realistic wellbores. The developed algorithm shows a significant improvement in calculation time compared to traditional nonlinear finite element approaches, while maintaining accuracy for complex scenarios. This method lays the foundation for real-time drilling optimization, and integration into automated drilling guidance systems.
Evaluating the Performance of a Cost-Effective Creep Testing Setup on Bismuth-Tin Alloy Specimens: Challenges and Future Directions
Authors: Hmadeh Lewaa , Essén Tora , Elahifar Behzad , Sangesland Sigbjørn 
Published: February 2025

Abstract
Well plugging and abandonment operations are critical in the oil and gas industry, especially when it comes to regulatory compliance and environmental safety. A key factor in this operation is the quality of the sealant used to close boreholes and prevent hydrocarbon migration. Bismuth alloys have emerged as a promising sealing material due to their distinctive properties. In the framework of P&A, investigating the creep behavior of the metal plug is essential to assess its sealing performance and long term integrity.
Creep, by definition, is a time-dependent deformation occurring when metals are subjected to a constant load at high temperatures over an extended period. Typically, creep testing machines evaluate how a material performs under these conditions. However, due to the unavailability of such machines and the necessity to test the creep properties of a bismuth-tin metal alloy, a low-cost creep testing setup was developed. This paper aims to investigate the creep properties of the bismuth-tin metal alloy at various temperatures (40, 60, 90, and 120°C) using the setup developed. The setup includes a steel chamber heated by an oven exhaust and a loading device attached to a support structure linked to the chamber. Inside the chamber, a bismuth-tin specimen is installed, and weights are applied to induce the load. A thermometer and a length gauge monitor the temperature inside the chamber and record the change in length, respectively. The maximum load applied to the specimen can be 24 kg.
Creep curves plotting strain versus time for the bismuth-tin alloy, under a constant load, were generated at different temperatures. Preliminary results indicate that creep effects become more pronounced at higher temperatures, where the cross-section of the tested specimen thins and ruptures more quickly. Although these results are not fully accurate, the study aims to evaluate the feasibility of this setup as a cost-effective alternative to expensive creep testing machines.
This work is part of an extensive in-house research that contributes to the understanding of how this unique material behaves under downhole conditions, thus leading to better P&A practices in terms of enhanced safety and operational efficiency, reduced leakage risks, and minimized costs. The ultimate goal of this technology is to be qualified for widespread usage as a barrier element in P&A operations, meeting the requirements of the NORSOK D-010 standard.
Impact of Change Implementation in the Driller's Control Cabin: A Human Factors Assessment with Design Implications
Authors: Arndt E. , Hoffart I. , Gabrielsen S. H. 
Published: February 2025

Abstract
Technological inventions and new ways of working transform the driller's control cabin into a place of change. Focusing on the human and the overall system is necessary to ensure proper implementation of changes. Research indicates that too little attention has been given to human factors and user-centric design in drilling operations in the past. Through identifying existing pain points, new design concepts for driller's control cabins have been developed. Interviews and rig visits were conducted for the assessment of the current situation, comprising questions about the human-machine interface, layout, work environment and workload. The main findings in the driller's cabin were information overload and screen clutter, inadequate workplace ergonomics and work environment, and distractions from core tasks for the driller. As an underlying reason, a lack of a holistic, human-oriented approach during the implementation of changes was observed. Based on these findings three complementary design concepts were developed. The first concept, a unified digital workspace, is defined through shared screens and/or data from several digital systems and shows operation-sensitive data in a consistent way. The second concept, a dynamic physical workspace, entails an ergonomically well-designed workstation regarding hardware, equipment and layout. The third concept, a cabin built for change, ensures that the cabin is fit for the future by remaining relevant and functional through ongoing technological advancements and evolving work practices. Every design concept can increase performance, safety and wellbeing, but technical and financial challenges must be met for the realization of each concept. If the current situation remains, the conditions in the driller's cabin will only deteriorate further in the future with potential consequences such as increased work-related illness, higher potential for operator error, and reduced operational performance.
A Comprehensive Statistical Analysis of Standard Tortuosity Computations in Unconventional Laterals
Authors: Lesso Bill , Rodriguez Edgar 
Published: February 2025

Abstract
Directional drilling tortuosity in unconventional laterals is accepted as a quality indicator. There is some agreement on the computation but none on any of the statistical characteristics of this tortuosity. This study presents a comprehensive analysis of tortuosity computed on a universe of 160,000 laterals drilled since 2010, aiming to establish statistical benchmarks and quality metrics for drilling and completion optimization.
The two most widely used tortuosity calculations — Large Scale Tortuosity (LST) and the University of Texas Tortuosity Index (UT-TI)—are applied to survey data from wells across Louisiana, New Mexico, Texas, and the four states in Appalachia, with publicly available data spanning from 2010 onward. Scripts were designed to calculate tortuosity in the lateral sections of the 115,700 verified wells drilled in these areas. The methodology for determining the start of the laterals, error checking of the survey data, and tortuosity calculation is outlined.
Statistically lateral tortuosity conforms to a log-normal distribution with a mean and standard deviation. The median tortuosity of all the wells is 1.505 deg/100ft. Rotary steerable systems (RSS) are gradually replacing positive displacement motors (PDM) in the time frame of this study. Laterals drilled with RSS's exhibit approximately half the tortuosity of those drilled with PDM's. This transformation is seen in the yearly distributions of lateral tortuosity. The findings offer insights into regional drilling practices, such as the prevalence of RSS use in Appalachia, and highlight the ability to track industry-wide transitions from PDM to RSS over time. The proposed metrics provide a valuable tool for improving wellbore quality and optimizing both drilling and completion designs.
Integration of Three Digital Twins: A New Perspective on Wellbore Stability and Drilling Optimization
Authors: Kristiansen T. G. , Navabi J. , Ødegård S. I. , Hovda S. , Hallaråker M. H. , Speirs D. , Bere A. , Roberts D. 
Published: February 2025

Abstract
It can be difficult to explain wellbore instability events with current state-of-the-art wellbore stability workflows. Many times, one may observe toolmarks on the cavings at surface, indicating contact between wellbore wall and drillstring/BHA. This work integrates three state-of-the-art digital twins within the areas of drillstring dynamics, wellbore hydraulics/hole cleaning and near-wellbore rock mechanics. The ultimate goal is to better understand field observations. A well where one had no signs of wellbore instability when drilling the section but had severe problems with cavings and pack-offs on the trips out is investigated. The section had to be drilled multiple times. Many cavings had toolmarks on them. From offset wells and wellbore stability models, mud weight was acceptable. The analysis describes results for when each digital twin is run individually and when all three twins are coupled together. Each digital twin contributes with a variety of additional information when run individually: The hydraulic and hole cleaning model indicate that the wellbore should be relatively clean with the parameters used, provided that the hole is everywhere in gauge. The drillstring model indicated that the greatest lateral forces were present in the numerous stick slip events in the section. Downhole memory data and drillstring simulations show that the lateral shocks in these stick slip events could exceed 100 g. Moreover, transverse forces in the sticking periods, could be as high as 100 kN. The more advanced rock mechanics model indicates there is a mechanism in an interval with fractured shales in Lower Hordaland formation where the problems occurred on the trips out. Fluid invasion into fractures, cyclic ECD pressure and gravity is driving the deformation. We see that as fluid is invading the fractures and blocks are pushed into the hole and create a under gauge hole. This paper describes the multiplicative benefit of combining all these digital twins. The drillstring dynamic models describes the forces and shocks that are acting on the formations. The rock mechanical models can use these forces to demonstrate how the hole has been broken down, while the hydraulic and cutting transport models can explain the effect on hole cleaning when the hole is out of gauge. Together the set of digital twins, describes the field observations in a new and very holistic way. A possible consequence of this effort is that the next generation of practicing engineers will at all times have access to a set of digital twins that are continuously working to holistically explain all field observations. Such a system of digital twins will likely be an enabling ingredient for the next generation of planning tools and automation efforts.
Filter Disk Materials for High-Pressure/High-Temperature Filtration Testing: Characterization and Comparison with Natural Sandstones
Authors: Ivanishin I. B. , Lu J. , Klemin D. , He W. 
Published: February 2025

Abstract
Filtration and filter-cake building properties are fundamental characteristics for drilling and completion fluid. In high-pressure/high-temperature (HP/HT) filtration laboratory testing, ceramic disks are widely used as filter media to simulate the exposed sandstone formation. However, the properties of filter disks significantly differ from those of sedimentary rocks. The objective of the work presented in this paper is to characterize the commonly used filter disk materials, compare the materials with sandstone formations, and provide a basis for the optimization of drilling fluid filtration testing. The porosity and permeability of American Petroleum Institute (API) filter disk materials and outcrop sandstones were determined. X-ray microcomputed tomography (microCT) scanning provided a 3D image of the pore spaces. MicroCT scanning, combined with thin-section analysis, scanning electron microscopy (SEM) observation, and mercury injection capillary pressure (MICP), allowed for extracting the parameters of the pore network such as pore and pore throat size distributions. The measured properties of the filter disk materials significantly deviated from the manufacturer's data, i.e., permeability—up to 36 times. For example, the provided permeability for the tightest filter material, API 10, is 775 md, while the measured permeability is only 21.4 md. The porosity of the filter disk materials ranges from 39.3% to 45.4%, which is up to two to three times higher than that of natural sandstones. The tightest filter material, API 10, has a porosity of 39.3%, while sandstones with similar permeability could be less than 20% porous. With evidence from microCT and thin-section images, API 10 is composed of tightly distributed spheres with diameters from 80 to 120 μm. The interparticle pores account for 12% porosity, with pore sizes ranging from a few to 60 μm. The sample's measured porosity is higher than that estimated from microCT. This discrepancy suggests that the majority—the remaining almost 30%—of the pore space is created by the presence of smaller intraparticle pores within the spheres. The other filter materials mostly consist of angular grains, creating different pore connectivity and pore-size distributions. This paper presents the first detailed characterization of filter disk materials. Understanding the properties of the widely used filter disk materials provides a basis for proper disk selection to closely match the simulated formation rock and appropriate interpretation of HP/HT filtration testing results. The study also provides a basis for (1) optimization of the manufacturing processes of filter materials, or (2) substitution of ceramic filter materials with real sedimentary rocks for HP/HT filtration testing.
Integration of Novel MWD and Rig Data for Remote Operations
Authors: Bonderover Eitan , Godumagadda Anil , Yang Libo 
Published: February 2025

Abstract
A novel low-cost MWD provides data for integration with a new cloud-based rig data architecture. The new and advanced algorithms in the MWD system improve both data rate and reliability, making it a suitable source of data. The integrated data architecture combines an edge platform at the rig with a cloud-based system accessible through a unified interface. This enables the deployment of advanced algorithms for drilling automation and data analytics to improve operational performance. The edge platform also supports machine learning models to be trained in the cloud across regional rig data and deploy them to the edge, quickly and efficiently. A series of case studies are presented. One case study shows the reliability and performance of the new MWD system. A further case study shows the seamless integration of data from downhole and surface into a unified database.