bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fast Modelling of Gas Reservoirs Using POD-RBF Non-Intrusive Reduced Order Modelling
Authors: Samuel Jemimah-Sandra , Muggeridge Ann Helen 
Published: November 2020

Abstract
We demonstrate that the non-intrusive reduced order model (NIROM) based on proper orthogonal decomposition and radial basis function interpolation is capable of gas reservoir simulation predictions with computational speed-ups of at least an order of magnitude and potentially many orders of magnitude. It can estimate 3-dimensional spatial pressure and saturation distributions as well as production data for unseen gas reservoir simulation scenarios produced at constant bottom hole pressure or gas rate control.
The NIROM is created from a series of training simulations performed using a commercial simulator. These simulations produce "snapshots" of the pressure and saturation distributions at equally spaced time intervals. Proper Orthogonal Decomposition (POD) is then used to project these data into a higher dimensional hyperspace. Radial basis functions (RBF) are then used to both estimate the dynamics of the system and the behaviour for unseen inputs (such as well BHP or rate). The approach is demonstrated using 3 different reservoir models, including a realistic reservoir model using data taken from the Norne field.
The NIROM simulations produce satisfactory predictions when compared to a commercial simulator, provided the unseen inputs are within the range of training parameters and time scale covered by the simulation. On average, these results were obtained using 10 training runs. The overall improvement in speed is insensitive to reservoir model complexities, such as local grid refinement, water coning or the presence of aquifers. Reservoir models with significant water production require more NIROM simulation subspace vectors to estimate performance, compared with cases without water production. Furthermore, we show that although NIROM works well for constant well controls over time it is less accurate when estimating behaviour when the imposed well rate changes quickly at different times in the simulation.
This is the first time that POD-RBF NIROM has been applied and evaluated for pressure depletion problems, such as occur in gas reservoir performance prediction.
Pushing Malaysia's Drilling Industry into a New Frontier: How a Distinctive Wellhead Design Enable Implementation of a Fully Offline Well Cementing Resulting in Significant Shift in Operational Efficiency
Authors: Abbas Fauzi , M. Nor Azrynizam , Chang Daryl , Czapor Wojciech 
Published: November 2020

Abstract
Traditionally, rigs are positioned over a well from the moment the surface casing is drilled till the installation of the wellhead Christmas Tree. This resulted in the loss of precious rig time as the rig is idling during online cementing. However, in Field A, offshore of Terengganu, Malaysia, a new approach has managed to eliminate such inefficiency drastically. This paper discusses the employment of offline cementing techniques made possible with distinctive wellhead technology, that enabled a fast, efficient, and safe drilling and completion.
In this offshore drilling program, five wells were successfully batched drilled and cemented offline by ingenious planning and skidding of the rig. As the first well has reached its depth, offline adapters with pressure compatible cementing heads and accessories are installed on the wellhead. This allowed the rig to skid to the adjacent wells to continue drilling while the previous well was being cemented with the use of full bore offline cementing adapters. Full bore offline cementing adapters helped maintained familiarity by allowing the use of simple conventional wiper plugs. These offline adapters are compatible with both mandrel and slip hangers and have pressure bleed off and monitoring capabilities. These steps were then repeated in all of the wells, from the surface casing till the tubing of these mono bore completions. Besides that, production and casing hangers come with barrier plug profiles allowing plugs to be pre-made up and tested. This reduced installation time on the rig floor and ensure that there was a positively tested barrier, before nippling down the riser. Hangers with seals also allowed for a single trip installation, further reducing rig time.
The five wells were drilled and completed in record-breaking time at an average of 7 days per well and below budget, resulting in a time saving of 31 hours and 18.5% of cumulative savings. In conclusion, this wellhead technology introduced a new approach to drilling and completion allowing vast improvement to the field economics and profitability to the development of marginal fields.
Unconventional Gas Development in Queensland, Australia: How Well Does it Align with the ‘Golden Rules’ of Gas?
Authors: Witt Katherine , Garnett Andrew 
Published: November 2020

Abstract
In 2012, the International Energy Agency (IEA) released the ‘Golden Rules for a Golden Age of Gas’ - a set of best practice guidelines for unconventional gas development designed to address key environmental and social risks and gain public acceptance of the industry. This study sought primarily to understand the extent to which the experience of developing a large-scale coal seam gas (CSG) to liquefied natural gas (LNG) industry in Queensland, Australia was seen to have aligned with the Golden Rules, and how well the Golden Rules were seen to contribute to public acceptance of the industry.
An evaluation tool was developed where the seven Golden Rules and their subclauses were adopted as criteria in a scorecard approach. We conducted interviews with 32 senior people who had been directly involved in the development of the CSG industry in Queensland, from local, state and federal governments, gas companies, host communities as well as researchers and consultant ‘experts’.
The Queensland experience of unconventional gas development rated reasonably well in relation to the Golden Rules, with scores of three or higher out of five for four of the seven rule categories. Across all the Golden Rules, industry performance scored more highly than the effectiveness of the policy/regulatory environment, highlighting the complex and sometimes conflicted roles of governments in developing a new industry. The rules addressing baseline measurement, full disclosure and engagement were seen as most important for public acceptance.
This study developed a new tool to evaluate perceived social and environmental performance of industry and effectiveness of governance in unconventional gas development applicable across different jurisdictional contexts. This application suggests that baseline measurements, open disclosure and public engagement should be the focus for building public acceptance. For new gas developments, these findings highlight the importance of having a robust regulatory environment in place that can coordinate activities and manage cumulative impacts.
Combating Production Loss Due to Paraffin Deposition: A Success Story of Thermochemical Stimulation in Western India
Authors: Qamruzzaman Mohammed , Khan Mandeep , Roy Dhirendra Chandra , Raman Ravi , Arora Sunil 
Published: November 2020

Abstract
Wax deposition during production and transport of paraffinic crude is one of the serious problems faced in downhole and surface operations. Crude oil often contains paraffins which precipitate and adhere to the liner, tubing, sucker rods and surface equipment as the temperature of the producing stream decreases in the normal course of production. Conventional methods of removal of paraffin deposits include chemical dissolution, hot oil/water circulation, mechanical scrapping and pigging. As an alternate to the conventional methods of paraffin removal, wax removal by exothermic chemical reaction also known as thermochemical stimulation is the technique in which the energy liberated from a suitable exothermic reaction is utilized for melting the paraffin deposits and has been shown to be more effective than the conventional treatments in literature.
A major challenge faced while execution of this technique is to control the reaction rate and provide sufficient delay time so that heating can be targeted to the desired depth of paraffin deposits without affecting the integrity of well completion equipment. Towards achieving this goal, this paper describes the key aspects of job design and execution that may significantly enhance the success of exothermic stimulation in wells susceptible to paraffin/organic deposition. The challenges encountered and respective solutions executed are presented through a case study of implementation in 5 onshore wells of western India. The paper also presents a lab validated mathematical model that may be used to predict the behavior of the exothermic formulation and help in optimization and quality control. The job execution procedure including solution preparation, quality testing, pumping, placement and monitoring has been streamlined from field experience to develop a standard operating procedure that may be referred for an effective implementation of this technique.
Effects of Gas Sorption Hysteresis on Gas Production from Organic-Rich Gas Shale Reservoirs
Authors: Ekundayo Jamiu , Rezaee Reza , Fan Chunyan 
Published: November 2020

Abstract
Gas desorption is one of the major gas transport mechanisms in shale gas reservoirs. However, its actual contribution to gas production is often masked by the indiscriminate use of adsorption-derived parameters for desorbed gas volumes during gas production calculations at reservoir conditions. Traditionally, it is believed that gas adsorption is fully reversible at the high-pressure, high-temperature conditions found in shale gas reservoirs.
In this paper, we studied methane adsorption and desorption isotherms using three shale samples at a reservoir temperature of 80oC. The resulting isotherms were modelled using the Langmuir model, following the conversion of measured excess amounts to absolute values. Lastly, a compositional 3D dual-porosity model was developed with CMG-GEM to test the effect of sorption hysteresis on gas production from a shale rock. For each sample, a base scenario, equivalent to a "zero-sorption" case, was compared against two other scenarios representing the two sorption processes.
For each sample, significant hysteresis was observed between the adsorption and desorption isotherms, with the desorption isotherms resulting in lower Langmuir parameters than the corresponding adsorption isotherms. For each process, Langmuir volumes showed a positive correlation with total organic carbon (TOC) contents. Also, the simulation results showed that gas production was lowest for the base case and highest for the adsorption case for each sample. This implies that neglecting the contribution of gas desorption can result in under-prediction of the gas production performances. On the other hand, using adsorption parameters to simulate desorbed gas volume could result in over-estimation of gas production performances.
A New Mixed Wettability Evaluation Method for Organic-Rich Shales
Authors: Tao Liang , Guo Jianchun , Halifu Mirinuer , Zeng Jie , Li Ming , Chen Chi , Zhao Yuhang 
Published: November 2020

Abstract
Rock wettability is the key factor affecting the microscopic distribution of fluids in rock pores and the interaction between fluid and rock. However, the shale from the Longmaxi Formation (LF) in Sichuan Basin is rich in organic minerals, which make the quantitative test of mixed wettability of shale very difficult. In this study, firstly, the micro-pore structure of shale was quantitatively characterized by scanning electron microscope (SEM). Secondly, a new experimental apparatus for shale water spontaneous imbibition under the conditions of formation temperature and confining pressure was designed. Finally, the wettability index was proposed to quantitatively evaluate the water wettability, oil wettability and mixed wettability of shale. The experimental results shown that the organic-rich shale has complex mixed wettability, which was both water-wet and oil-wet. The contact angle of shale samples tested with distilled water were 13.5° and 70.5°, and the contact angles tested with kerosene were 0° and 9.6° at room temperature. The higher temperature the stronger shale hydrophilicity will be, and the water wettability of shale increases with the imbibition time.Therefore, a large amount of fracturing fluid spontaneously permeates into the shale micro-nano pores in the process of hydraulic fracturing, which is an important reason for the low flowback efficiency of shale gas wells. The research results provide effective guidance for the optimization of flowback system.
A Protocol for Developing a Clinical Practice Guideline of Moxibustion in the Treatment of Lumbar Disc Herniation
Authors: Hua Fanghui , Xiong Jun , Zhang Haifeng , Xiang Jie , Huang Shouqiang 
Published: November 2020

Abstract
Background: Lumbar disc herniation(LDH), as a disease with great disturbance to life and work, is known as the origin of the severe and disabling forms of nerve root pain. Recognized as an increasingly widely accepted treatment, the efficacy of moxibustion on LDH has been affirmed. However, clinical practice guidelines (CPG) for the treatment of LDH with moxibustion have not been developed. Therefore, we will carry out this work following the accepted methodological quality standards.Methods: The new CPG will be developed according to the Institute of Medicine (IOM), the Appraisal of Guidelines for Research & EvaluationⅡ (AGREEⅡ) and WHO guideline handbook. And then determine recommendations based on high-level evidence. We will set up a Guideline Working Group and define clinical issues according to the PICO principles (Population, Intervention, Comparison, Outcomes). After evidence syntheses and several rounds of Delphi process, we will reach the consensus. In making the guideline, Patient values or preferences, results of peer review, and interest statements are all within the bounds of what we must consider. Results: As the study is not yet complete, no results can be reported.Conclusion: So far, we will develop the first CPG for moxibustion of LDH strictly based on systematic methodologies in China. This CPG will establish the standard of LDH in moxibustion therapy.Registration number: IPGRP-2020CN034.
Microbiome in Acute Exacerbation and Stable Phase of COPD: A Descriptive and Comparative Study of 16s rRNA Sequencing and Metagenomic Sequencing
Authors: Chang Kang , Zou Xiaohui , Li Zhengtu , Yang Zifeng , Gao Jianpeng , Yang Guoru , Zhang Yong , Li Xue , Zhang Xiaoqi , Liu Yingmei , Cao Bin 
Published: November 2020

Abstract
Background: The role of bacteria in different courses of chronic obstructive pulmonary disease (COPD) has not been very clarified. In this study, sputum samples from patients at different courses of COPD were collected to analyze the differences of the structure and function of respiratory microbiome in different courses of COPD.Results: Our study involved 38 patients with acute exacerbation of COPD (AECOPD). Among them, 42 sputum samples were collected from the acute exacerbation of COPD (Of these 38 patients, 4 patients also collected sputum from the second acute exacerbation phase), and 12 sputum samples were collected from the stable phase of COPD (6 of the above 38 patients). Firmicutes, Proteobacteria, Bacteroidetes and Actinobacteria dominated the phylum in all the COPD samples, while Streptococcus, Neisseria, Haemophilus and Prevotella is the top 4 species in the cohort. Salmonella, Salmonella, Pseudomonas and Proteobacteria achieved higher abundance in AECOPD group. Samples from AECOPD patients showed higher α diversity. Moreover, genes annotated to K07481(the function is related to transposase) and K16087(the function is related to hemoglobin/transferrin/lactoferrin receptor protein) in stable subgroup showed higher abundance than that in acute exacerbation subgroup. Compared to samples from stable COPD, Proteobacteria contributed the most antibiotic resistance genes. Conclusions: There are differences in the function and metabolism of respiratory microbiome in patients with different course of COPD. Word count: 218/350
Investigation of Radiation Shielding Efficacy of Vanadium–Tellurite–Antimonite Semiconducting Glasses
Authors: Rammah Yasser , Olarinoye I.O. , El-Agawany F.I. , Mahmoud K A , Akkurt Iskender , Yousef El Sayed 
Published: November 2020

Abstract
Effects of antimony trioxide (Sb2O3) on neutron and gamma-radiation shielding parameters of tellurite vanadio-antimonite glasses with compositions 40TeO2-(60-x)V2O5-xSb2O3: 0 ≤ xSb2O3 ≤ 10 mol% coded as (TVS0-TVS10) were investigated. The mass attenuation coefficients (MAC) were evaluated using the Monte Carlo simulation code (MCNP-5) and WinXcom program for photon energies in the range of 15 keV to 15 MeV. The SRIM program was used to compute the stopping power and projected range of the charged particles, such as proton and alpha particles, on the investigated glass samples. Based on the theoretically evaluated MAC, some shielding parameters were computed, such as linear attenuation coefficient, electric cross-section, atomic cross-section, effective atomic number, half-value thickness (HVT), and the mean free path. The EXABCal program was applied to predict the level of the photons accumulation in the investigated glass samples (buildup factors). The effective cross-section for fast neutrons was computed theoretically based on the fast neutron effective removal cross-section (ΣR ) for the constituting components. Results revealed that the maximum values of MAC exceed in the range between 28.9-31.3 cm2/g with increasing the Sb2O3 substitution ratio between 0-10 mol %, respectively. In contrast, the HVT values decrease with an increase in the increment of Sb2O3 rate. The maximum (ΣR) was obtained for glass coded TVS0 among the investigated glasses. Results concluded that the higher Sb2O3 concentration in TVS glasses leads to an increase in their capability to apply in several radiation shielding applications.
Expression of Wilms’ Tumor Gene 1 and Its Clinical Significance in Children with Acute Lymphocytic Leukemia
Authors: Yin Mengmeng , Liu Aiguo , Zhang Ai , Wang Yaqin , Hu Qun 
Published: November 2020

Abstract
Background: Wilms’ Tumor Gene 1 (WT1) is a potential valuable parameter in prognosis of childhood acute lymphoblastic leukemia (ALL). However, studies on prevalence of WT1 and its correlation to clinical features and prognosis in pediatric patients were not well done. In this study we attempted to identify the correlation between WT1 and childhood ALL.Methods: The expression levels of WT1 in bone marrow cells of 188 children diagnosed with ALL from 2015 to 2018 were detected using real-time quantitative polymerase chain reaction (RQ-PCR). The relationship between expression levels of WT1 and patients’ characteristics, remission status (complete remission/relapse), fusion genes and prognosis of childhood ALL were analyzed and revealed. Results: 1. 147 (78.2%) cases had positive WT1 expression, and the average level was 1.76 (0.3, 6.03) %. 2. The CR and relapse rates of ALL children with positive WT1 were not significantly different from those of WT1 negative group, respectively (87.76% vs 82.93%, P=0.42 and 14.29% vs 17.1%, P=0.658). 3. The WT1 expression level in patients at CR was significantly lower than when at diagnosis (P<0.001) and the expression of WT1 increased obviously after induction therapy in 21 patients who relapsed (P=0.003) .4. The WT1 expression was related to lymphadenectasis (P=0.004) and immunophenotyping (P=0.009), but not to fusion genes (P=0.912). Conclusion: The WT1 in ALL children can be employed as an independent tool to evaluate the prognosis and curative effect of the disease.
Safety of reopening universities and colleges using a combined strategy during coronavirus disease 2019 in China: a cross-sectional study
Authors: Cai Guoqi , Luo Sihui , Zheng Xueying , Yue Tong , Zhou Peng , Jin Tengchuan , Chu Xinmin , Lu Zhaohui , Hu Xiaowen , Shen Zuojun , Xue Tian , Weng Jianping 
Published: November 2020

Abstract
Background There is no consensus as to when and how to reopen schools during the coronavirus disease 2019 (COVID-19) pandemic. This study aimed to evaluate the safety of reopening universities and colleges using a combined strategy in China.Methods This cross-sectional study included 13,116 staffs and postgraduate students who have returned to the four campuses of the University of Science and Technology of China from 17 February (students returned from 12 May) to 2 July 2020. The returning to school was guided by a combined strategy including use of personal protective equipment, management of transportation, serological and nucleic acid tests for COVID-19, quarantine, and restrictions in and out of campus. Epidemiology history and COVID-19 related symptoms (fever, cough, and dyspnoea) were recorded in a subset of participants using an online questionnaire.Results Among 13,116 participants, 4067 tested for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acid and no positive results were identified. Of 9049 participants who chose to conduct antibody tests, 28 (0.3%) tested positive but no one was confirmed by the additional viral nucleic acid tests. Online questionnaires were collected from 5741 participants (mean 25.1 years, 35% female). High-risk exposures and COVID-19 related symptoms were reported in 8.3% and 7.4% of participants, respectively. Comorbidities (hypertension, diabetes, chronic pulmonary disease, and chronic kidney disease) were rare (0.2%-1.5%). Conclusions Using a combined strategy for COVID-19 prevention and control, safely reopening of universities and colleges in low-risk regions is possible and laboratory screening for SARS-CoV-2 infection may not be necessary. Further studies need to cautiously evaluate the safety of reopening schools, if any, in the middle- and high-risk regions.