bluuebunny/crossref_metadata_2025 huggingface dataset:
AN APPROACH TO RELIABILITY ANALYSIS OF AIRCRAFT SYSTEMS FOR A SMALL DATASET
Authors: OKORO Onyedikachi Chioma , ZALISKYI Maksym , SERHII Dmytriiev , ABULE Ibinabo
Published: March 2023

Data-driven predictive aircraft maintenance approach typically results in lower maintenance costs, avoiding unnecessary preventive maintenance actions and reducing unexpected failures. Information provided by a reliability analysis of aircraft components and systems can improve an existing maintenance strategy and ensure an optimal maintenance task interval. For reliability work, the exponential distribution is typically used; however, this approach requires substantial amounts of data, which often may not be generated by aviation operations. Therefore, this study proposes a method for reliability analysis given a small dataset. Real-life historical data of an aircraft operating in Nigeria validate the proposed approach and prove its applicability.
Guerrilla Marketing in the 21st Century: A Systematic Analysis of the Discipline Through a Literature Review, a Taxonomy, and Identification of the Most Relevant Variables
Authors: Zarco Carmen , Herzallah Doaa
Published: March 2023

In recent years, given the enormous competition for new products and services, many companies have begun to behave more creatively in an aim to be the best in the market. “Guerrilla marketing” refers to an advertising technique that uses unconventional and cost-effective approaches, employing a variety of strategies that reduce costs. Since the emergence of this concept in the second half of the last century, substantial research has looked into its application and usefulness. This study presents a systematic survey of the field of marketing and advertising: by analyzing the main scientific publications on guerrilla marketing through content analysis in the Web of Science, Scopus, and EBSCO databases. One hundred and sixty-four articles were analyzed in depth and divided into two separate lists: one with publications corresponding to Hutter and Hoffmann’s first classification, and another corresponding to the new variables that emerged from the in-depth study that was carried out. As a consequence, a new taxonomy is proposed for the field, based on the identification of some novel variables characterizing the different existing approaches.
Higher Penetration Depth of 1064 NM Compared to 905 NM Laser Light Into Biological Tissue Is Only Relevant for Surface Layers and Insignificant for 10 MM Tissue Depth Onwards
Authors: Kaub Leon , Schmitz Christoph
Published: March 2023

The choice of parameters for laser beams used in the treatment of musculoskeletal diseases is of great importance. First, to reach high penetration depths into biological tissue and, secondly, to achieve the required effects on a molecular level. The penetration depth depends on the wavelength since there are multiple light-absorbing and scattering molecules in tissue with different absorption spectra. The present study is the first comparing the penetration depth of 1064 nm laser light with light of a smaller wavelength (905 nm) using high-fidelity laser measurement technology. Penetration depths in two types of tissue (porcine skin and bovine muscle) were investigated. The transmittance of 1064 nm light through both tissue types was consistently higher than of 905 nm light. The largest differences (up to 5.9%) were seen in the upper 10 mm of tissue, while the difference vanished with increasing tissue thickness. The higher penetration was most likely due to a combination of lower absorption in hemoglobin and less scattering at larger wavelengths, and not due to absorption in melanin. Overall, differences in penetration depth were comparably small and high peak power and short pulse lengths of laser light seem to be more important to efficiently treat deep musculoskeletal diseases.
Super-twisting sliding mode control for brushless doubly fed reluctance generator based on wind energy conversion system
Authors: Oualah O. , Kerdoun D. , Boumassata A.
Published: March 2023

Introduction. Recently, wind power generation has grown at an alarming rate in the past decade and will continue to do so as power electronic technology continues to advance. Purpose. Super-twisting sliding mode control for brushless doubly-fed reluctance generator based on wind energy conversion system. Methods. This paper deals with the robust power control of a grid-connected brushless doubly-fed reluctance generator driven by the variable speed wind turbine using a variable structure control theory called sliding mode control. The traditional sliding mode approach produces an unpleasant chattering phenomenon that could harm the system. To eliminate chattering, it is necessary to employ a high-order sliding mode controller. The super-twisting algorithm is one type of nonlinear control presented in order to ensure the effectiveness of the control structure we tested these controllers in two different ways reference tracking, and robustness. Results. Simulation results using MATLAB/Simulink have demonstrated the effectiveness and robustness of the super-twisting sliding mode controller.
STATISTICAL ACCOUNTING IN INTERNATIONAL TOURISM
Authors: Aleksandrova Viktorija , Zhadan Tetiana , Strygul Larysa
Published: March 2023

To form the information basis necessary not only for the functioning of tourist companies, but also for regional authorities responsible for tourism development in the region it is necessary to know the existing forms of statistical observation in the field of tourism, statistical standards of the World Tourism Organization (UNWTO) and the United Nations (UN), methods of statistical accounting of tourism in countries leading the level of development of the national tourism sector. Application of UN and UNWTO statistical standards allows to conduct more complete and comparable statistical studies, as well as to make statistical forecasts of tourism development as a component and important part of the economy of any region. Statistical tasks in tourism include: statistical analysis of visitors, analysis of efficiency of accommodation facilities, tourist consumption; organization of maintenance and analysis of tourist statistics; obtaining full information about qualitative and quantitative characteristics of tourist flow in the region and its dynamics. To solve these problems effectively, it is very important to use the long-term experience of statistical developments of the countries with developed tourist infrastructure, and, accordingly, tourism statistics. And also it is necessary to allocate tourism statistics as a separate direction of accounting and statistical research, taking into account the specifics of information collection, processing techniques, generalization and analysis of the initial data aimed at practical application of the results of the analysis. The need to form a methodology of data collection for the study of the state of tourism, which will meet modern requirements comparable with international generally accepted accounting systems. To form such a system, it is necessary to refer to the experience of foreign countries, to consider the basic methods of statistical accounting existing in modern world practice.
TOWARDS THE INTEGRATED PROTECTION OF HISTORIC NETWORKED ARCHITECTURAL RESOURCE OF WATER TOWERS IN WESTERN POLAND
Authors:   Zachodniopomorski Uniwersytet Technologiczny w Szczecinie, Poland Wydział Architektury Katedra Projektowania Architektonicznego, Barełkowski Robert
Published: March 2023

The present paper treats the network of railway water towers as a group of architectural objects forming the system of multi-dimensional connections - historic networked architectural resource (HiNAR). HiNAR functions within dimensions: technological one, reflecting technical and processrelated basis of the erection and functioning of towers as railway facilities; the organisational one as an object serving specific transport connections; the typological one at levels – local/regional, national or international. Perceiving a single tower as an architectural object does not allow to assess its significance and thus to correctly categorise the object in connection with the needs of conservator’s protection, as it is necessary to accept the role that it may be serving in a broader dimension.
THE SPECIAL FEATURE OF THE SINGLE-FAMILY RESIDENTIAL PLANNING AND COMPOSITION IN THE ROPCZYCE AND SĘDZISZÓW POVIAT
Authors:   Rzeszów University of Technology Faculty of Civil and Environmental Engineering and Architecture Department of Architectural Design and Engineering Graphics, Raś Beata
Published: March 2023

The main aim of the article is to show the significance of the spatial order concerning, in particular, the single-family residential architecture of the Ropczyce and Sędziszów poviat. Single-family architecture of small towns in the Subcarpathian region constitutes the majority of buildings and defines their landscape. Referring to the regional architecture of the selected area and to contemporary foreign practices in the subject of critical regionalism, the author defines the most important features of regional development and solutions that may be a guideline for the design of singlefamily residential buildings. The characteristics emphasize the value of traditional housing architecture, contributing to drawing attention to the preservation of spatial order and building the identity of the region.
SELECTED EDUCATIONAL BUILDINGS AND THEIR ROLE IN CONTEMPORARY EDUCATION, ON THE EXAMPLE OF CZĘSTOCHOWA
Authors:   Politechnika Częstochowska, Poland Wydział Budownictwa, Katedra Budownictwa Lądowego, Tubielewicz-Michalczuk Malwina
Published: March 2023

The article presents five selected architectural objects of Częstochowa, a city located in the southern part of Poland, known all over the world for the foot pilgrimage, the goal of which is Jasna Góra. It is presented how architects, when designing ingenious and modern buildings, at the same time revitalize the past, creating architectural and landscape places that disseminate and bring humanistic, historical and natural knowledge closer to both the residents and newcomers. The research concerns buildings that, in contrast to various functions, play an educational role. In each of them, the architects maintain the cultural and spatial continuity of the city, which received the town rights in the fourteenth century.
GLASS HINGED DOOR SYSTEM, NEW SOLUTIONS
Authors:   PIU DESIGN Sp.z o.o. Szczecin, Poland, Warych-Mitas Dorota , Włoszczyńska-Lewińska Anna ,   PIU DESIGN Sp.z o.o. Szczecin, Poland
Published: March 2023

The aim of the research was to develop a technology for glass – composite doors with a tilting slat integrated with the frame hidden in the wall, and to implement it on the Polish and international markets. The research has resulted in new technological solutions in relation to conventional glass doors, eliminating the current limitations in terms of height, width, weight and applicability of composite glass based on glass with infill. The study was conducted following the TRL (Technology Readiness Levels) system.
FEATURES OF LANDSCAPE AND URBANOF OIL AND GAS FACTORIES OF THE WESTERN REGION OF UKRAINE
Authors:   Lviv Polytechnic National University Institute of Architecture Department of Architectural Design, Habrel Mykola , Savchuk Andriy ,   King Danylo University, Department of architecture and construction, Savchuk Oksana ,   King Danylo University, Department of architecture and construction
Published: March 2023

The main purpose of the article is to identify the features of landscape and urban of oil and gas companies in the Western region of Ukraine. Twenty-two enterprises which are located in IvanoFrankivsk, Lviv and Ternopil regions were analyzed. The analysis includes: localization of objects and their grouping by functional types taking into account the territorial and historical context; formation of methodical tools, determination of criteria for assessment of landscape and urban properties; the obtained research results are summarized according to the defined evaluation criteria. It is an attempt to find new approaches to the reorganization of facilities, taking into account their condition and functioning.
NEOLITHIC CIRCULAR ENCLOSURES – MONUMENTAL BUILDINGS BUILT TWO MILLENNIA BEFORE THE PYRAMIDS – ALSO IN WESTERN POMERANIA
Authors:   West Pomeranian Technical University in Szczecin. Poland Faculty of Architecture Department of Architectural Design, Arlet Piotr Krzysztof
Published: March 2023

As a result of the popularization of aerial archaeology methods in the last twenty-five years, a number of remains of monumental buildings from the Neolithic period, called roundels, have been discovered in western Poland. They had a circular plan and an external diameter of 70–200 m. They consisted of one or several circles of wooden palisade, which in turn were surrounded by circles of earth ditches. The northernmost site of this type was discovered in Nowe Objezierze near Cedynia – less than 80 km south of Szczecin. The author postulates to include these sites built of wood and earth in the history of architecture of our region, and shift its starting point to around the 49th–47th century BC, i.e. 2000 years before the construction of the Egyptian pyramids.
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.
IOT-Based Sumo Robot Control Using Blynk Software
Authors: Falah Agus Hayatal , Syahrorini Syamsudduha , Wisaksono Arief , Prasetyo Yoga Eko
Published: March 2023

The sumo robot robot has been around since 1990, it was first intrudeced in Japan. Robot suno is also contested by rule that have the same weight. The sumo robot can be controlled remotely by utilizing bluethoot as a communication medium for maneuvering cpmmands on the robot. But using bluethooth has the disadvantage of short range. In this study utilizing iot to communicate between Android smartphones and robot. From the results of testing the connection on the nodemcu esp 8266 microcontroller has a speed of 4.6 seconds. Stepdown circuit test with 5 Vdc result, lippo 3 cell battery 12.54 Vdc test result. Bts7960 driver test result can rotate clockwise and conterclockwise. Manuver test result with the iot system with four commands made Blynk software robot can manuver on command, forward, backward, turn left and right.
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

Whitings, 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 < 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

Understanding 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

The 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

Low-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

Unconventional 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

The 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

In 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

As 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.
Distributed Real-Time Multi-Pad Steam Allocation Optimization
Authors: Sibaweihi Najmudeen , Trivedi Japan
Published: March 2023

In Steam-Assisted Gravity Drainage (SAGD) recovery, optimal real-time steam allocation from a shared steam generator to the physically coupled multi-pads can significantly improve long-term performance goals. However, multi-pad real-time optimization (RTO) with first-principle models can be computationally intensive. Furthermore, general-purpose optimization algorithms in RTO do not consider the future state beyond the prediction horizons to be optimized and treat the optimization problem as a long-term optimization process. Since steam is the primary cost factor in SAGD, Key Performance Indicators (KPI) such as Net Present Value (NPV), when used in RTO, result in low steam injection impeding steam chamber growth during the build-up and normal SAGD operational phase. Therefore, balancing steam chamber development and economics becomes essential for SAGD well-pads using RTO to meet long-term goals.

In this contribution, we implement the Alternating Direction Method of Multipliers (ADMM) and a dynamic data-driven model to reduce the computational cost of RTO. ADMM coordinates in real-time field-wide use of shared steam generation. The shared steam generation is a market commodity traded between the pads, with global coordination in real-time perturbation of their market prices. Four SAGD KPIs are implemented for a multi-pad RTO of the SAGD normal operations phase to see which KPI eventually grows the steam chamber without negatively affecting the long-term economic performance.

A SAGD field with four pads with 33 well-pairs shows that for all four pads, an economic-based KPI limits the achievement of long-term goals because it cannot account for the future state beyond the horizon under consideration due to hindered steam chamber growth. For the steam chamber expansion and bitumen recovery KPI, high recovery and economic performance are achieved, but with a high resource requirement, leading to a high carbon footprint. On the other hand, an alternating economic and bitumen recovery KPI achieves high economic performance while minimizing resource requirements that decrease carbon footprint.
An Analytical Approach for Optimizing the Subcool of Non-Condensable Gas (NCG) Assisted Heavy Oil Production: Predictions & Limitations
Authors: Rosi Giuseppe , Zhu Da , Izadi Hossein , Mahmoudi Mahdi , Fattahpour Vahid , Roostaei Morteza , Tuttle Aubrey , Stevenson Jesse , Sutton Colby , Gates Ian
Published: March 2023

NCG is increasingly being co-injected with steam in heavy oil production systems to reduce heat loss and greenhouse gas emissions, as well as to maintain reservoir pressure. Given increased use of NCG co-injection, the validity of conventional subcool models must be revisited since they assume that the steam chamber is comprised of water alone. The current study makes modifications to the pure-steam hydrostatic subcool model, as well as the Yuan & Nugent (2013) subcool model to account for the presence of NCG in the steam chamber. Using typical values from the Athabasca oilfield, the study then compares the liquid-height predictions made by the original and modified models and proposes rules-of-thumb that correct for the presence of NCG. In general, increasing NCG in the steam chamber results in a reduction in subcool relative to pure steam. According to modified hydrostatic model, to achieve a liquid-pool height equal to that of pure steam injection, the subcool must be increased by 0.60K per 1% increase in the vapor-phase molar fraction. In contrast, over a wide range of production rates and drawdowns, the modified Yuan & Nugent (2013) model predicts that to achieve a liquid-pool height equal to that of the pure steam case, the subcool must be increased by 0.66K per 1% increase in the vapor-phase molar fraction. Despite the rule-of-thumbs being qualitatively in line with expectations, they suffer from the inability to accurately calculate subcool from field data. The final section of the paper reviews limitations of subcool as a well performance metric and proposes an alternative method of assessment that relies on data that are more readily available to operators.
Fluids Migration Behind Casings: An Offshore Well Integrity Issue Restoration Experience of AGM043 in Gabon, West-Africa
Authors: Ebaga Ololo Jestril , Ndong-Ovono Dieudonné
Published: March 2023

Minimizing risks in offshore oil and gas production facilities is of upmost importance for oil producers to reduce possibilities of liability claims, hydrocarbons production rate loss, and most importantly environmental impacts. In this regard, well integrity parameters such as MAASP and MAWOP become key tools to carefully follow and watch production tubings and annulus pressures behaviors at the surface.

AGM043 is an oil producing well which presented a high downgraded situation mainly with abnormal pressure in the annuli A and B and the christmas tree not holding the pressure. The pressure rate observed in the annulus B (104 bars) was considered higher than the limit set as per the MAASP (72 bars) presenting a risk of fracture at the 13-3/8″ casing shoe.

To regain full integrity of the well, since purging the annuli did not contribute to pressure stabilization and due to the presence of gas (mainly methane), actions were taken to conduct a well killing job split in four phases:

Phase 1: Purging, investigate communication point between tubing and annuli, echometer for fluid level determination. Phase 2: Well killing by bull heading in the tubing and lubricate and bleed in the annuli. Phase 3: Establishment of a double barriers Phase 4: Valves changes and test of Christmas tree integrity.

This manuscript discusses the rise of an abnormal pressure behavior in the annular, its management, and the lessons learnt at the end of the integrity regain after the killing job offshore Gabon. The experience gained can be applied to other wells with similar problems.
Complex Mass Transfer Phenomena in Bitumen Solvent Systems
Authors: Chaustre Ruiz Andres Javier , Mayorga Ariza Maria Daniela , Babak Petro , Kantzas Apostolos
Published: March 2023

The overall objective of this study was to perform a series of diffusion experiments between liquid hydrocarbons (e.g., propane, pentane, and toluene) and bitumen or heavy oil to observe and analyze mass transfer in the systems. Some difficulties, such as the complex behavior of the phases, the high viscosity, and the opacity of hydrocarbons, generate the need for different techniques to measure mass transfer coefficients in heavy crude oils. In this work, X-ray tomography was used for such measurements. The measurements are carried out in environments where the sedimentation of solids is encouraged. To achieve this, a novel setup was designed and assembled to measure the mass transfer in these systems based on the density profiles established over time in aluminum containers that contain fluids. The containers were regularly scanned to track the behavior of the density profiles over time. The data was collected and analyzed, obtaining interesting results, which will be important as a starting point for future research related to systems that integrate interactions between solvents and oils in the recovery processes. Due to the novel results obtained in the original test, 7 sets of experiments were carried out, all with unique characteristics, trying to analyze its results in detail.

One of the objectives is to analyze if the mass transfer is uniform and constant during long periods. This work shows results that were never published in the previous literature, such as partial miscibility when mixing n-propane and bitumen, oil swelling, oil shrinking, asphaltene precipitation and sedimentation, total miscibility, and the effect of adding pure asphaltenes and calcium carbonate to the mixture, among others. In addition, the impacts on the effectiveness of the proposed processes for the production and refining of these solvents are discussed.
Synergistic Hydrate Inhibition by Bovine Serum Albumin With Kinetic Hydrate Inhibitors
Authors: Singh Ankur , Suri Ajay , Date Avadhoot
Published: March 2023

Using kinetic hydrate inhibitors (KHIs) can be technically and economically an ideal solution to achieving deep-sea hydrate risk management, but biodegradability requirements in many offshore locations, such as the North Sea, can restrict their usage. The problem could be addressed by developing so-called "green hydrate inhibitors." Many natural chemicals have been tested to achieve this goal. However, their performance has not been found to be at par with the non-biodegradable high-performing commercial KHIs. It has been shown by some studies that although natural chemicals cannot perform very well alone, they perform quite well when used as synergists with KHIs, possibly due to their large molecular structures with both hydrophilic and hydrophobic functional groups leading to increased steric hindrance to hydrate formation and their higher molecular viscosity possibly causing a reduction in the gas and water mass transfer rate to the hydrate nucleation sites. Thus, in this study, a protein prevalent in the circulatory system of bovine species called bovine serum albumin (BSA), was tested as a synergist with four KHIs used in academia for research and industry (PVP, PVCap, CKHI-1, and CKHI-2). Due to BSA's biodegradability, biocompatibility and nontoxicity, it is widely employed in the medical sector as a drug delivery agent. Standard constant cooling rate hydrate formation experiments at 1°C/h are performed to measure the induction time (delay in hydrate nucleation) and average hydrate growth rate within 1 hour of hydrate nucleation to evaluate the hydrate-inhibiting performance of various blends made of BSA and the four KHIs. The Induction time (IT) and the average hydrate growth rate (AHGR) delivered by each of the 0.5 wt % of the individual four KHIs are compared with the IT, and AHGR obtained from the blend of 0.25 wt % respective KHI mixed with 0.25 wt % BSA. It was found that the blends made from PVP, PVCap and CKHI-2 provided higher ITs (up to 66% for CKHI-2) and lower AHGRs (down to -60% for CKHI-2) compared to the ITs, and AHGRs obtained from the individual commercial KHIs at the same total dosage of 0.5 wt%. The blend CKHI-1 and BSA gave almost the same IT and AHGR as obtained from CKHI-1 alone. Along with high performance, the blended solutions also provide higher biodegradability as compared to commercial KHIs.