bluuebunny/crossref_metadata_2025_split huggingface dataset:
Closed-Loop Digital Workflow to Drive Drilling Performance
Authors: Li D. , Cherel A. , Zhang P. , Tang K. H. , Byrd C. , Mendoza D. , Procel E. 
Published: October 2023

Abstract
Drilling performance is becoming the top differentiator in the market, especially in highly competitive US land basins. This drives operators to input more energy into the system with higher rev/min, flow, and weight on bit (WOB). In many cases this energy is transformed into drilling dysfunction (shock and vibration [S&V]) instead of higher rate of penetration (ROP). To minimize drilling dysfunction and maximize energy efficiency, a fully digital and closed-loop workflow was developed.
The workflow begins with use of a proprietary at-bit sensor, which captures high-resolution at-bit measurements of three-axis acceleration, torsional vibration, and rev/min. The tool is placed inside any existing bit and does not require an additional sub, thus not introducing extra connections, bottomhole assembly (BHA) integrity risk, and/or length.
The high-resolution data is automatically processed and analyzed to reveal critical drilling dynamics, which are replicated in a digital model. This creates a highly accurate virtual environment in which to evaluate bit design, eliminating the cost and risk of real-world trial and error, enabling efficient, fit-for-purpose introduction of new technologies.
The new digital workflow was first used in a challenging, interbedded application in East Texas. High frequency at-bit measurements were used to develop a new bit and data-driven operating parameter roadmaps. These yielded improved drilling performance, with 69% higher ROP, better dull conditions, and 67% lower vibrations locally, when compared to the direct operator offsets.
The workflow was then used in a curve/lateral application in the Permian Basin, known for challenging S&V conditions. Key performance targets were single-run to total depth (TD), high dogleg severity (DLS) output in the curve, and record ROP in the lateral. A new bit was designed, and recommended drilling parameters were defined within the data-driven virtual environment. Field testing confirmed the model’s predictions, with a 10% average increase in ROP.
High-resolution at-bit downhole measurements coupled with digital simulation capabilities have led to development of a new workflow driving the evolution of drill bit design. Instead of the traditional trial and error approach that costs resources, time, and performance, the new workflow with data-enhanced digital modelling and virtual drilling environment enables increased confidence, optimized solutions, and decreased cycle time.
Preventive Strategies to Avoid Recurring Hydrate Blockages in the Marlim Oil Field
Authors: Gomes G. Sena , Pinto R. Leite Alves 
Published: October 2023

Abstract
This work presents strategies adopted to solve what at the time was the largest production loss related to flow assurance in the company: the recurrent formation of hydrate blockages in flowlines of multiple wells of a FPSO in the Marlim oil field in Brazil.
These blockages, which reoccurred frequently for various reasons, required a comprehensive plan for resolution. The main hydrate blockage cases were related to operational mistakes, problems in topside equipment, problems in subsea equipment and inaccurate procedures.
In response to this challenge, a systematic approach was employed to identify and implement viable solutions. The key point of this work revolves around the same strategy - prevention - which was divided into three different courses of action: equipment, procedures and people.
After implementing these processes, the results were exceedingly positive. That which was a recurrent problem became a steady state of zero production loss due to preventable hydrate blockages for 1.5 years, until the end of the FPSO unit’s production life.
GPU-Accelerated NMR T2 Simulator Incorporating Surface Roughness Effect
Authors: Li Yiteng , Zhu Weiwei , He Xupeng , Kwak Hyung , Hoteit Hussein 
Published: October 2023

Abstract
NMR T2 simulation supplements laboratory experiments that numerically predicts petrophysical properties of digitized rock samples. Recent research demonstrated that the pore shape irregularity acts as surface roughness at the macroscopic point of view and its effect on NMR T2 relaxation is overlooked. So far, neither commercial nor open-source software explicitly suppresses the surface roughness effect on nuclear magnetization decay. This work proposes an innovative GPU-accelerated NMR T2 simulator incorporating the relaxation inhibition factor (RIF) to effectively control the NMR relaxation rate.
The proposed GPU-accelerated NMR T2 simulator allocates a thread to control the random movement of a particle; thousands of particles can be moved simultaneously using modern GPU devices. An image-based pore surface roughness characterization technique is applied to parameterize surface roughness into a dimensionless coefficient. The RIF is defined as a function of the roughness coefficient to suppress accelerated surface relaxation and is distributed along solid-pore interfaces. When a walker collides with a solid voxel, it accesses the local RIF that effectively controls the nuclear magnetization decay of individual particles.
Numerical results show that the proposed simulator accurately models the NMR T2 relaxation so that the pore structures interpreted from NMR T2 responses agree with the ground truth. This demonstrates that the surface roughness effect has to be removed for pore structure characterization. From the perspective of efficiency, the proposed simulator could achieve two to three orders of magnitude speedup, which exceeds the efficiency of commercial software for high-fidelity simulations. The proposed simulator honors greater physical consistency than existing software by assigning surface relaxivity and RIF to solid voxels rather than treating them as particle-carrying parameters. It is the first NMR T2 simulator that explicitly suppresses the surface roughness effect in numerical simulations, which provides an integrated platform for accurate and effective characterization of pore structures from digital rocks.
A Novel Shale Well Production Forecast Model Achieves &gt;95% Accuracy Using Only 1.5 Years of Production Data
Authors: Haider Syed , Saputra Wardana , Patzek Tadeusz W. 
Published: October 2023

Objective
Reliable production forecasting for shale wells is crucial for investment decisions, optimized drilling rate, energy security policies, and informed green transition scenarios. The industry has struggled with inaccurate production estimates from decline curve analysis (DCA) and from a long production history requirement for data-driven models. We have developed a state-of-the-art, physics-guided, data-driven model for accurate production forecast of unconventional wells for up to 10 years into the future. With an error of less than 5%, our hybrid model requires only 1.5 years of production data. The method facilitates long-term production diagnostics, well survival probability estimates, and profitable economic decisions.

Method
The hybrid state-of-the-art production forecast method combines our τ-M physical scaling model with the higher-order derivatives of the production rate. For a set of 4000 wells, the first 1.5 years of production data were used to develop a universal hybrid model to estimate the pressure interference time, τ, for each well. The estimated τ is used to calculate the stimulated mass, M, of individual wells using the physical scaling curve. Finally, the data-driven estimate of τ, and physics-driven estimates of M are used to forecast future well production and well survival probability with time.

Results
The robustness of the hybrid model has been tested on 6000 new wells in the Barnett, Haynesville, Eagle Ford, and Marcellus shale plays. Using the initial 1.5 years of production data and a single hybrid model, the predicted pressure interference time, τ, for 6000 wells has an R2 of 0.98. The maximum error in the predicted cumulative production of 2000 Barnett wells for any given year between the 2nd year of production to the 15th year of production is only 2%. Similarly, the maximum error in the predicted cumulative production for Marcellus (500 wells), Haynesville, (1500 wells) and Eagle Ford (200 wells), is 2%, 5%, and 3%, respectively. The achieved outstanding accuracy is further used to calculate the well survival probability with time and optimize the future drilling rate required to sustain a given energy demand.

Novelty
We have developed a new, robust state-of-the-art hybrid model for unconventional well production forecasting. The model achieves an outstanding accuracy of &gt; 95% and uses only the initial 1.5 years of production data. Early and accurate estimation of future production governs future investment decisions, re-fracking strategy, and improved energy security strategy.
Geochemistry Study for the CO2-H2S Injection for Storage: Experimental and Modelling
Authors: Zaidin M. F. , Razak A. A. , Amin S. M. , Mohsin N. , Pin Y. W. , Tewari R. D. 
Published: October 2023

Abstract
Realizing the risk and possible impacts of the H2S presence in the injected CO2 towards the overall of Carbon Capture and Storage (CCS) operation in carbonate reservoir, it is recommended to have an accurate knowledge of these behavior for safe and efficient CO2 injection and storage in the reservoir formation. Limited data available from the literature suggested that additional laboratory studies are required to measure and understand the behaviour of the CO2-H2S mixture on the carbonate rock reactions, and therefore the aim of the study is to measure the key geochemical reaction kinetics parameters between injected CO2- H2S, brine and reservoir rocks and their effects to the fluid, rock properties (chemistry, mineralogy, porosity, permeability). The core samples from Y Field have been selected and used as a case study since Y Field has been identified as one of the potential CO2- H2S storage sites and there are preserved core samples available. Briefly, the mixture of CO2-H2S gas with the H2S concentration level up to 500 ppm is co-mixed with brine water and aged with core samples under Y Field reservoir condition for duration of 30 days via static batch ageing using PT chamber. Cores and effluent collected at the end of ageing days were analyzed to measure the changes on the key geochemical parameters (i.e, rock porosity, permeability, mineralogy & images from CT scan) between post-ageing and pre-ageing. The experimental results will validate the geochemical models at such H2S concentrations, and it will greatly enhance the accuracy of the models used to predict CO2-H2S storage capacity and containment for high H2S fields. This study provides critical information on the kinetic rates, which are crucial inputs for both short- and long-term projections. The incorporation of these accurate data into the models will improve their ability to predict the behaviour of CO2 and H2S in the storage and containment process, thereby providing more reliable and actionable insights for future high H2S fields.
A Simplified Mathematical Model for Formation Caprock Integrity Incorporating Creep Deformation: Implications for Hydrogen Underground Storage
Authors: AlDhuhoori M. , Belhaj H. , AlHameli F. , Moncada A. 
Published: October 2023

Abstract
This research effort aims at addressing the Geo-mechanical aspect of hydrogen underground storage, specifically caprock integrity tests using creep deformation modelling. This study also concentrates on time and injection rate dependent processes which could lead to permanent deformation of reservoir rocks during injection and production cycles due to the cyclical pore-pressure changes. The newly developed model includes a new term that accounts for pore expansion and compaction, and was coupled to the simplified power law. The model was then verified against uniaxial laboratory data and validated by comparing it to the power law model. The idea is to simulate several injection and production cycles of vast amounts of hydrogen into a reservoir that is saturated primarily by saline formation water (aquifer) under certain conditions to assess caprock integrity. The model has been validated using the uniaxial test data provided by Wu et al.2020 and achieved good accuracy. Furthermore, the model was compared to the simplified power law with no apparent advantages. This is attributed to the low-pressure differential and hence it is expected that the model will yield better estimations when applied to high pressure differential cases.
Reducing Hydraulic Fracturing Breaking Pressure by Using High Power Lasers
Authors: Batarseh Sameeh I. , Alerigi Damian P. San Roman , Zefzafy Ibrahim , Enezi Hazaa 
Published: October 2023

Abstract
This paper presents a hybrid approach to reduce hydraulic fracturing braking pressure by integrating high-power laser energy with hydraulic fracturing operations. The innovative technology reduced the formation's breaking pressure by 68%, improving the operation efficiency. The technology is safe, efficient, and cost-effective, providing a long-term solution to fracturing technology. The field system is already mobilized and deployed for different applications.
High-power laser technology has been tested and proven to reduce breaking pressure for all rock types regardless of strength and composition, including carbonate, shale, and sandstone formations. The success of over two decades of intensive research has led to the development of the first high-power laser field system. The system's design is enclosed, providing safe and environmentally friendly operation; it consists of a laser energy generator, nitrogen tank, coiled tubing, and tool. The function of the tool is to control the size and the shape of the beam that targeted formation. The process is done by utilizing the power of the laser in the form of a controlled beam creating a sudden increase in the formation's temperature, causing micro-fracture initiation and, as a result weakening the formation.
The technology was tested on several rock types, and the pre and post-analysis on the rocks have been conducted, including uniaxial stress tests and ultrasounds; the result shows that the breaking pressure was reduced by 68%. The reduction is due to the laser/formation interaction and mechanism; the instant laser beam causes sudden heat in the formation, resulting in fracturing initiations and collapsing the mineral. The laser is used as an enabler along with the hydraulic fracturing operation.
Applying high-power laser technology to reduce braking pressure in hydraulic fracture operation is innovative and cost-effective. The precise control of the beam allows targeting the formation and orienting and creating weaker formations for hydraulic fracturing. The technology is cost-effective, environmentally friendly, and safe technology.
Application of Machine Learning and Dimensional Analysis to Evaluate the Performances of Various Downhole Centrifugal Separator Types
Authors: Ojeda Laura Camila Osorio 
Published: October 2023

Abstract
Pumping artificial lift techniques, such as rod pumps and ESPs, are applied for gassy wells more than ever before. Gas largely affects pump performance, causing cavitation, gas locking, low production, and run-life shortening. These phenomena have made downhole separators a critical part of such installations. There are multiple categories of downhole separators, with various techniques developed to assess and improve their performances, but no general guidelines are established for their application. Through dimensional analysis and machine learning techniques, this paper aims to establish key parameters in the performance characterization of this equipment, and prediction models are attempted.
A comprehensive literature review is conducted to understand factors (retention time, turbulence, and head) influencing the efficiency of this equipment and collect the available downhole separator performance data. This information is collected to identify the optimum conditions for each separator type, considering the effects of liquid and gas rates and other flow parameters. The data collected from various research projects over the last 20 years are combined to make a comprehensive centrifugal downhole separation databank.
The available data show that most separators provide separation efficiencies higher than 79% if the downstream pressure-controlling systems and liquid levels are adequately monitored. The separation efficiencies decline as the liquid and gas rates increase past an upper limit of around 800 BPD. Furthermore, the separator's control system is a critical factor that adds to the uncertainty, significantly affecting the separation efficiency calculation. Data analysis of the Buckingham Pi Theorem for dimensionless numbers is used to compare the performances of different downhole separator classes, and machine learning is applied to identify a robust prediction model. Two dimensionless numbers, the Weber number, and the gas Reynolds number, were found to largely dominate the behavior of the separators’ performance. Results provide a fundamental source and a valuable guideline for downhole liquid-gas separation, particularly in artificial lift applications.
Assessing the impact of the wildlife trade in West Africa (Benin): functional diversity matters too
Authors: DJAGOUN Chabi A.M.S. , ZANVO Stanislas , AZIHOU Fortuné , NAGO Gilles , DJAGOUN Joël , VODOUHÊ Fifanou , DJOSSA Bruno , ASSOAGBADJO Achille , LEPRIEUR Fabien , SINSIN Brice , GAUBERT Philippe 
Published: October 2023

Abstract
We tackle the potential impact of bushmeat markets (BM) and traditional medicine markets (TMM) on the functional diversity of mammalian communities in southern Benin, West Africa. A hybrid approach combining direct observations, DNA-typing and questionnaires allowed us to identify 94 species-level taxa across 11 mammalian orders, the greatest ever reported numbers for African wildlife markets. TMM sold species of high conservation concern or regulated by international conventions and sourced among all the taxonomic orders and bioclimatic zones of the country. BM were taxonomically and functionally 100% nested within TMM. However, functional richness was high in both markets, impacting nine diet specializations and five ecological functions, which included seed dispersion (frugivores, folivores and omnivores), prey regulation (carnivores and invertivores), browsing (folivores), grazing (omnivores) and fertilization (nectarivores). TMM likely jeopardized the regulatory, structural and production functions of the sourced ecosystems as they sold species with the greatest body weights and generation lengths, and smallest litter sizes, including large herbivores and keystone predators. BM, despite their restricted range, sourced among a non-selective taxonomic and functional spectrum and as such, also represent a significant threat to ecosystem functioning in southern Benin. The functional database that we provide can serve as a starting point to pursue the quantification of functional diversity in African mammals and further investigate the impact of wildlife markets on ecosystem functioning in tropical Africa. Overall, long-term surveys of the two types of wildlife markets are needed to accurately quantify the threat they constitute to mammalian biodiversity and the sustainability of ecosystem services.
Early detection of Sergentomyia minuta (Diptera: Phlebotominae) in Madrid, Spain An early warning for the temporal dynamic modification of leishmaniosis’ epidemiology?
Authors: Milagres Tarcísio de Freitas , de-Felipe Marcos López , Silva Onilda Santos da , Gálvez Rosa 
Published: October 2023

Abstract
Global changes, such as climate change, represent a worldwide risk for the management of leishmaniosis. The transmission profile can be modified by several mechanisms, mainly through the distribution and ecology of the vectors, causing direct effects on their survival, generation time, reproduction rate and population size. Sergentomyia minuta is an endemic species of the Old World, considered the most abundant in some areas of Spain. Even though S. minuta has traditionally been seen as herpetophilic, several recent research suggest this species to play a potential role in Leishmania infantum transmission. Furthermore, the Toscana virus has previously been detected in S. minuta and the potential role of this species in the epidemiology of this emerging arbovirus is still uncertain and needs further research. At the end of April 2023, a total of 10 individuals of S. minuta were collected in Torrelodones (Madrid, Central Spain), this being the first collection of sandflies of any species during the month of April in this region. While it is known that climate change can have a significant impact on sand fly distribution and behavior, little is known about the microscale effect of this variation on vector biology and ecology. The early detection of S. minuta in an endemic area of leishmaniosis such as the Madrid region suggests the potential impact on the epidemiology of these diseases. Furthermore, this early detection may act as an early warning of the risk of temporal dynamic changes in Phlebotomus species in response to global change.
Personality and Interest in General Practice: Results from an Online Survey among Medical Students.
Authors: Krauthausen Maike , Leutritz Tobias , Hagen Pamina Eva , König Sarah , Simmenroth Anne 
Published: October 2023

Abstract
Background
The growing shortage of General Practitioners (GPs) is a European-wide challenge, especially in rural areas. Facing this problem in Germany, funding programmes and voluntary courses during medical studies aim to enhance students’ interest in general practice. To further increase the number of GPs, medical training should support students in making career choices that suit them as a person. Can taking students’ personality traits into account add value to this?
Objectives
We hypothesise that students pursuing a career in general practice show outlined manifestations of personality traits that influence their interest.
Methods
In March 2021, we started an ongoing online survey among medical students at the University of Würzburg aiming to collect longitudinal data about the ‘Big Five’ personality traits and aspects of career choice. Until December 2022, we invited three cohorts of first-year beginners and one cohort each of third-, fifth- and sixth-year students via email to participate in line with data protection guidelines. We performed partial correlation and ANCOVA analyses to examine the relationship between students’ interests in general practice and their personality traits, controlling for gender and age as possible confounding factors.
Results
According to our research, the personality traits of agreeablenessand conscientiousness were the most significant factors that impacted students' decision to pursue general practice as a specialty. There was a significant positive correlation for agreeableness (r=.18, p<.001) and a negative correlation with conscientiousness (r=-.11, p=.03), while the results for openness(r=-.05, p=.35), extraversion(r=.076, p=.14), and neuroticism (r=.077, p=.059) were not significant. High extents of agreeablenessand low extents of conscientiousnesscould predict a greater interest in General Practice. Female students scored higher than males on all personality traits. Most interest in choosing General Practice as a specialty was stated by female students with high extents of agreeableness.
Conclusion
This study shows a link between students’ interest in becoming a GP and their personality. The curriculum ought to offer opportunities for students to develop their personalities and prepare for their professional careers. Considering personality can also help to support students in their career choices and to identify promising students for programs promoting the next generation of GPs.