bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical Mechanistic Study of In-Situ CO2 EOR – Kinetics and Recovery Performance Analysis
Authors: Hussain Sadam , Wu Xingru , Shiau Ben 
Published: September 2021

Abstract
The success of supercritical CO2 Enhanced Oil Recovery (EOR) cannot be duplicated if the cost of CO2 transposition and processing becomes prohibitive. Research results of the in-situ CO2 EOR (ICE) approach offered a potential technology for many waterflooded stripper wells that lack access to affordable CO2 sources. Previously the ICE synergetic mechanisms were only qualitatively attributed to oil swelling and viscosity reduction due to the preferential partition of CO2 into the oleic phase. This study aims to quantify the contributions to recovery factors from several plausible mechanisms with numerical modeling and simulation.
First, the urea reaction was modeled as the CO2 generating chemical decomposing to CO2 and ammonia in the reservoir conditions. The CO2 partitions into oil, which leads to the reaction continuation to generate more CO2. The resulting ammonia largely left in water may further react with certain crudes to generate surfactants, thus, decrease the oil/water interfacial tension (IFT). It is expected that the oil containing CO2 also has a lower IFT with water. The reaction kinetics under different temperatures were incorporated into the numerical model. A numerical model featuring the synergetic mechanisms was built including stoichiometry and kinetics of urea reaction, oil swelling effect, oil viscosity reduction, and IFT reduction effect on the relative permeabilities. The laboratory experiments, pore volume injection versus oil saturation were history matched for three different oils including Dodecane, Earlsboro oil, and DeepStar oil. The phase behavior was modeled with the equation of state (EOS) under different mole fractions of CO2. The reaction kinetics were also modified to history match the laboratory experiment.
The estimated reduction of oil viscosity was calculated, 76% for Earlsboro oil, 91% in DeepStar oil, and 75% in dodecane oil. The oil swelling factors ranged from 1.60% to 19% in the three lab models, which translates to the recovery factor of oil. The endpoints of relative permeability were modified to account for the recovery contribution to the IFT and viscosity reduction. The impact of reaction kinetics on oil swelling and recovery factor was also determined, and they are not numerically close to reaction kinetics used in the lab cases. The matched reaction kinetics, activation energy and reaction frequency factor for the dodecane laboratory experiment were 91.80 kJ/gmol and 6.5E+09 min−1. The study concluded that the incremental recovery due to oil swelling ranges between 3.16% and 18.30%, and then from 12.91% to 41.59% is due to IFT reduction for all the cases. The relative permeability and urea reaction kinetics remained the most uncertain parameters during history matching and modeling the ICE synergetic mechanisms.
Selection of Representative Scenarios Using Multiple Simulation Outputs for Robust Well Placement Optimization in Greenfields
Authors: Mahjour Seyed Kourosh , Santos Antonio Alberto Souza , Santos Susana Margarida da Graca , Schiozer Denis Jose 
Published: September 2021

Abstract
In greenfield projects, robust well placement optimization under different scenarios of uncertainty technically requires hundreds to thousands of evaluations to be processed by a flow simulator. However, the simulation process for so many evaluations can be computationally expensive. Hence, simulation runs are generally applied over a small subset of scenarios called representative scenarios (RS) approximately showing the statistical features of the full ensemble. In this work, we evaluated two workflows for robust well placement optimization using the selection of (1) representative geostatistical realizations (RGR) under geological uncertainties (Workflow A), and (2) representative (simulation) models (RM) under the combination of geological and reservoir (dynamic) uncertainties (Workflow B). In both workflows, an existing RS selection technique was used by measuring the mismatches between the cumulative distribution of multiple simulation outputs from the subset and the full ensemble. We applied the Iterative Discretized Latin Hypercube (IDLHC) to optimize the well placements using the RS sets selected from each workflow and maximizing the expected monetary value (EMV) as the objective function. We evaluated the workflows in terms of (1) representativeness of the RS in different production strategies, (2) quality of the defined robust strategies, and (3) computational costs. To obtain and validate the results, we employed the synthetic UNISIM-II-D-BO benchmark case with uncertain variables and the reference fine- grid model, UNISIM-II-R, which works as a real case. This work investigated the overall impacts of the robust well placement optimization workflows considering uncertain scenarios and application on the reference model. Additionally, we highlighted and evaluated the importance of geological and dynamic uncertainties in the RS selection for efficient robust well placement optimization.
A Competency-Based Approach to Addressing the Leadership Gap in the Oil and Gas Industry
Authors: Howes C. Susan , Taylor Robert W. 
Published: September 2021

Abstract
As oil and gas industry technical professionals land their first supervisory roles, gaps in their leadership skills often become apparent. Years of technical education and training have prepared them well for roles as individual technical contributors, but stronger business, management, and leadership skills are needed as they move into emerging leadership roles in which they direct others.
Competency assessments of first-level supervisors and mid-career experienced hires are conducted to determine mission-critical leadership gaps. This process is done in alignment with competency-focused job descriptions that enumerate key soft skills needed in each leadership role and build on a sound foundation of technical competency. Bringing emerging leaders together as a group enhances their networking opportunities as they advance through the program; including experienced hires helps them become attuned to the company's management style. Learning opportunities can include face-to-face instruction, webinars, e-learning, online resources, exercises, business simulations, and coaching and mentoring.
Building future leaders is key to succession planning. Introducing experienced hires to the leadership styles of the company ensures the successful integration of new talent into the team. A competency-based approach to assessing emerging leaders provides the roadmap for creating a deep bench of candidates for future roles in executive management. Experienced instructors and mentors are crucial to ensuring the leadership program delivery is aligned with the corporate mission, vision and values. The delivery of the leadership development program can be self-sustaining if program graduates and external expert facilitators are incorporated into the delivery of the program to future cohorts.
Technical professionals progress through supervisory/management positions on their respective career ladders primarily by ‘learning on the job' rather than through formal training. This paper looks at differences between the current state of supervisory development and what professionals actually need in leadership skills. These are new skills needed for transitioning from supervisor/manager to an effective leader. New methods of digital delivery allow greater interaction between participants and instructors. Building an innovative leadership development program enhances the company's brand and attracts and retains top talent.
Cost-Effective Development of Shallow and Poorer Quality Gas Reservoir in Mature Field
Authors: Abdulhadi Muhammad , Mohd Said Hani , Zubbir Ahmad Uzair , Ling Evelyn , Mohd Nasir Mohamed Azlin , Anoar Imran , Abdul Rahim Abdul Rahman , Elias Rohani , Sanchez Paul , Sharif Rizam , Abdul Ghapor Zamri , Ismail Nurhanim , Kew Yoong Hau 
Published: September 2021

Abstract
The Cement Packer approach has been successfully implemented to pursue and monetize minor gas reservoirs of poorer quality. Due to its critical role in power supply to meet the nation's needs, license to operate gas fields oftentimes come with contractual obligations to deliver a certain threshold of gas capacity. The cement packer method is a cheaper alternative to workovers that enables operators to build gas capacity by monetizing minor gas reservoirs at lower cost.
Group 1 reservoirs are the shallowest hydrocarbon bearing sand with poorer reservoir quality and relatively thin reservoirs. The behind-casing-opportunities in Minor Group-1 reservoirs previously required a relatively costly pull-tubing rig workover to monetize the reservoir. Opportunities in two wells were optimized from pull –tubing rig workovers to a non-rig program by implementing Cement Packer applications. The tubing was punched to create tubing-casing communication and cement was subsequently pumped through the tubing and into the casing. The hardened cement then acted as a barrier to satisfy operating guidelines. The reservoir was then additionally perforated, flow tested and successfully monetized at a lower cost.
Tubing and casing integrity tests prior to well entry demonstrated good tubing and casing integrity. This is critical to ensure that cement will only flow into the casing where the tubing was punched. Once the cement hardened, pressure test from the tubing and from the casing indicated that the cement has effectively isolated both tubulars. Subsequent Cement Bond Log and Ultrasonic Imaging Tool showed fair to good cement above the target perforation depth. These data supported the fact that the cement packer was solid and the reservoir was ready for additional perforation. Taking into account the reservoir quality, it was decided to perforate the reservoir twice with the biggest gun available to ensure the lowest skin possible. Post perforation, there was a sharp increase in the tubing pressure indicating pressure influx from the reservoir. Despite that, casing pressure remained low, confirming no communication and thus the success of the cement packer.The well was later able to unload naturally due to its high reservoir pressure, confirming the producibility of the reservoirs and unlocking similar opportunities in other wells. Additionally, the cement packer approach delivered tremendous cost savings between $6 – 8 mil per well.
Besides confirming the reservoirs' producibility,the success also unlocked additional shallow gas behind casing opportunities in the area.This method will now be the first-choice option to monetize any hydrocarbon resources in reservoirs located above the top packer.
Mitigating Water Production from High Viscosity Oil Wells in Unconsolidated Sandstone Formations
Authors: AL-Rashidi Hamad , Hussein Hussein Mahmoud Reda Aly , Erhamah Abdulaziz , Malik Satinder , AL-Hajri Abdulrahman , Almeida Dwane , Salehi Nazanine , Omonte German , Zaitoun Alain 
Published: September 2021

Abstract
Large reserves of High-Viscous Oil in Kuwait calls for Improved Oil Recovery scenarios. In Kuwait unconsolidated sandstone formations, the sandstone intervals represent extensive reservoir intervals of sand separated by laterally extensive non-reservoir intervals that comprise finer-grained, argillaceous sands, silts and muds. The reservoir is shallow with high permeability (above 1000 mD) and under bottom aquifer pressure support. Due to strong viscosity contrast between oil and water, after breakthrough, the water cut rises quickly resulting in strong loss of production efficiency. Mitigating water production is thus mandatory to improve production conditions.
The candidate wells have 2 to 3 open intervals in different rock facies with comingle production. The total perforated length is between 38 and 48 ft. Production is through PCP at a rate of around 300 bpd and BS&W is between 71 and 87%.
The technology applied utilizes pre-gelled size-controlled product (SMG Microgels) having RPM properties, i.e. inducing a strong drop of relative permeability to water without affecting oil relative permeability. The size is chosen to selectively treat the high-permeability water producing zones while preserving the lower-permeability oil zones. The chemical can also withstand downhole harsh conditions such as salinity of around 170,000ppm and presence of 2% H2S.
The treatment consisted of bullhead injection of 300 bbls of pre-gelled chemical through tubing. The first results seem very favourable, sincefor two wells, the water cut has dropped from 80 to 40% with almost same gross production rate. The incremental oil is more than 100 bopd. The third well did not show marked change after WSO treatment. The wells are under continuous monitoring to assess long-term performance.
Such result, if confirmed, may lead to high possibilities for the improvement of heavy-oil reservoir production under aquifer support by mitigating water production with simple chemical bullhead injection.
Pore-Scale Imaging of Tertiary Low Salinity Waterflooding in a Heterogeneous Carbonate Rock at Reservoir Conditions
Authors: Selem Ahmed M. , Agenet Nicolas , Blunt Martin J. , Bijeljic Branko 
Published: September 2021

Abstract
We investigated pore-scale oil displacement and rock wettability in tertiary low salinity waterflooding (LSW) in a heterogeneous carbonate sample using high-resolution three-dimensional imaging. This enabled the underlying mechanisms of the low salinity effect (LSE) to be observed and quantified in terms of changes in wettability and pore-scale fluid configuration, while also measuring the overall effect on recovery. The results were compared to the behavior under high salinity waterflooding (HSW).
To achieve the wetting state found in oil reservoirs, an Estaillades limestone core sample was aged at 11 MPa and 80°C for three weeks. The moderately oil-wet sample was then injected with high salinity brine (HSB) at a range of increasing flow rates, namely at 1, 2, 4, 11, 22 and 42 µL/min with 10 pore volumes injected at each rate. Subsequently, low salinity brine (LSB) was injected following the same procedure. X-ray micro-computed tomography (micro-CT) was used to visualize the fluid configuration in the pore space. A total of eight micro-CT images, with a resolution of 2.3 µm/voxel, were acquired after both low salinity and high salinity floods. These high-resolution images were used to monitor fluid configuration in the pore space and obtain fluid saturations and occupancy maps. Wettability was characterized by measurements of in situ contact angles and curvatures.
The results show that the pore-scale mechanisms of improved recovery in LSW are consistent with the development of water micro-droplets within the oil and the expansion of thin water films between the oil and rock surface. Before waterflooding and during HSW, the measured contact angles were constant and above 110o, while the mean curvature and the capillary pressure values remained negative, suggesting that the HSB did not change the wettability state of the rock. However, with LSW the capillary pressure increased towards positive values as the wettability shifted towards a mixed-wet state. The fluid occupancy analysis reveals a salinity-induced change in fluid configuration in the pore space. HSB invaded mainly the larger pores and throats, but with LSW brine invaded small-size pores and throats. Overall, our analysis shows that a change from a weakly oil-wet towards a mixed-wet state was observed mainly after LSW, leading to an incremental increase in oil recovery.
This work established a combined coreflooding and imaging methodology to investigate pore-scale mechanisms and wettability alteration for tertiary LSW in carbonates. It improves our understanding of LSW as an enhanced oil recovery (EOR) method for potential field-scale applications. The data provides a valuable benchmark for pore-scale modelling as well as an insight into how even modest wettability changes can lead to additional oil recovery.
Simulation of a Cyclone Separator to Improve the Efficiency of Gas Purification from Mechanical Impurities
Authors: Abrorov Khasan 
Published: September 2021

Abstract
This paper provides an overview of methods for dealing with mechanical impurities, justifies the choice of a suitable method and prototype for the conditions of the field. A methodology for designing cyclone separators of JSC "NIIOGAS" is presented, in accordance with which a theoretical calculation of the design of a cyclone separator was carried out. A solid model of a computational cyclone separator in the SolidWorks software was created, a computer simulation of a gas flow with the presence of mechanical impurities of various granulometric composition was carried out, based on the results of which conclusions were made.
Plunger Style Optimization by Machine Learning
Authors: Zhong Zhikai 
Published: September 2021

Abstract
Oil and gas wells often need artificial lift technologies to help extract reservoir fluids as the wells age and the reservoir pressure decreases–among those technologies is plunger lift. Plungers are metal cylinders that fit snug inside the tubing in which they are still able to slide freely. Plungers are often used with gas lift: they get pushed up and down the tubing like a piston to unload all the fluids by periodically shut in and open up the well. Many plungers contain a one-way valve that enables them to fall through flow easily and rise to the surface with a seal to prevent fluid slippage. There are many styles of plungers based on their weight, fall speed, and embedded one-way valves’ mechanism, and they should be used in different kinds of wells. Plungers can be grouped into five major different categories. This project utilizes machine learning and data analytics to predict what the most optimal type of plungers is for a given well in order to reduce gas injection and maximize liquid production.
To accomplish this project, more than two million rows of raw plunger lift production data were queried using SQL, a database query language, then pivoted, cleaned, and turned into a data table with approximately two hundred twenty thousand rows. The data came from about 900 wells with a time span of more than 400 days of production. Utilizing the python package Scikit Learn's random forest regressor, five separate machine learning models were trained, tuned, and cross-validated to predict the daily revenue and/or efficiency of a well if it were to run with the corresponding style of the plunger. The models were able to achieve about .85-.90 accuracy scores. On the other hand, a data visualization guide was built to visualize all the past plunger operation history to analyze the efficiency of a type of plunger; it also acts as an educational tool for operators to study the behaviors of different plungers in various wells.
The results of this project were achieved by field testing. Given that there was a time constraint, approximately ten wells were tested with eight of them showing revenue and/or efficiency improvements of 5-10%. More testing, tuning, and data gathering need to be done in the future to improve the project to apply at a larger scale.
Leukocyte and Monocyte Counts as Predictors for Metabolic Syndrome, Hypertension and Type 2 Diabetes in Taiwan Citizens: a 9-year Longitudinal Study
Authors: Li Yen-Wei , Kao Tung-Wei , Kuo Chao-Yin , Chang Pi-Kai , Chen Wei-Liang , Wu Li-Wei 
Published: September 2021

Abstract
Cardiovascular disease whose correlation with metabolic syndrome and diabetes has been well established. As an aspect of preventive medicine, we conducted a 9-year longitudinal study to identify the relationship between easily measured hematologic parameters, future metabolic syndrome (MetS), hypertension and type 2 diabetes mellitus (T2DM) according to age distribution. Divided into three groups according to age (young age: <40, middle age: ≧40 and <65 and old age: ≧65), 10,328 participants, receiving general medical inspection at the health management centre of Tri-Service General Hospital (TSGH) in Taiwan from 2007 to 2015, had been enrolled in the present study. Through multivariate regression analyses, the hazard ratio (HR) of total and subtype leukocyte count for MetS along with its components, hypertension and T2DM were demonstrated. All MetS components revealed significant association with total leukocyte count in multivariate regression models. Total leukocyte count was associated with future MetS, hypertension and T2DM despite of age at first, but failed in adjusted HR for the old group. Additionally, monocyte count showed significant association with all the aforementioned diseases only in middle-aged subjects but failed in the other two groups. Our results explore the promising value of total leukocyte count and monocyte count to identify the high-risk subjects, especially meddle-aged ones, having MetS, hypertension, and T2DM whether in the present or future.
MicroRNA composition of plasma extracellular vesicles: a harbinger of late cardiotoxicity in long-term survivors of acute lymphoblastic leukemia treated with doxorubicin
Authors: Totoń-Żurańska Justyna , Sulicka-Grodzicka Joanna , Seweryn Michal , Pitera Ewelina , Kapusta Przemyslaw , Konieczny Paweł , Drabik Leszek , Kołton-Wróż Maria , Chyrchel Bernadeta , Nowak Ewelina , Surdacki Andrzej , Grodzicki Tomasz , Wołkow Pawel 
Published: September 2021

Abstract
The use of doxorubicin is associated with an increased risk of acute and long-term cardiomyopathy. Despite the constantly growing number of cancer survivors, little is known about the transcriptional mechanisms which progress in the time leading to a severe cardiac outcome. It is also unclear whether long-term transcriptomic alterations related to doxorubicin use are similar to transcriptomic patterns present in patients suffering from other cardiomyopathies. Here we have sequenced miRNA from total plasma and extracellular vesicles (EVs) from 66 childhood acute lymphoblastic leukemia survivors treated with doxorubicin and 61 healthy controls (254 samples in total). We analyzed processes regulated by differentially expressed miRNA and cross-validated our results with the data of patients with clinically manifested cardiomyopathies. Our analyses indicate that the circulating compartment used for inspection should be selected with particular attention. miRNAs contained within EVs may be particularly informative in terms of cardiomyopathy development and may regulate pathways related to neurotrophin, transforming growth factor beta or epidermal growth factor receptors (ErbB). Among miRNAs differentially expressed in vesicles, which additionally are also most variable between groups, we identified those correlated with echocardiographic parameters, including miR-144-3p and miR-423-3p and respectively for plasma miRNAs: let-7g-5p, miR-16-2-3p. Among these, vesicular miR-144-3p correlates with the highest number of echocardiographic parameters and is also differentially expressed in the circulation of patients with dilated cardiomyopathy. We also show that in ALL survivors' distribution of particular miRNAs, e.g., miR-184 between plasma and EVs is different than in healthy controls. This suggests persistent alterations within the cellular sorting and exporting system.