bluuebunny/crossref_metadata_2025_split huggingface dataset:
Drilling Problems Forecast System Based on Neural Network
Authors: Borozdin Sergey , Dmitrievsky Anatoly , Eremin Nikolai , Arkhipov Alexey , Sboev Alexander , Chashchina-Semenova Olga , Fitzner Leonid , Safarova Elisaveta 
Published: October 2020

Summary
Optimization, digitalization and robotization of oil and gas technological processes based on the use of artificial intelligence methods are among the prevailing trends of the 21st century. The drilling industry is a prime example of these phenomena. The vector of oil and gas drilling is shifting towards complex objects. The improvement of well drilling technologies allows drilling in geological conditions where it was previously impossible. The construction of wells leads to disruption of the natural thermodynamic and stress-strain state of rocks. It is necessary to take into account all the processes occurring in the well and the near-wellbore zone during drilling for the timely recognition of the onset of various complications and accidents. The average time to eliminate complications and accidents is 20-25% of the total well construction time. The task of reducing this indicator is highly relevant. To solve this problem, the most modern technologies are involved, including machine learning algorithms. The main difficulties encountered when using these technologies are the requirements for artificial neural networks for the minimum necessary number of complications or their representable set for the correct "training" of these networks. This report describes how this problem was solved using a full-scale drilling simulator. The drilling simulator makes it possible to recreate a digital twin of a real well and simulate an almost unlimited number of complications of various kinds on it. This approach allows you to create a sample of the required size for the most efficient training and testing of neural network algorithms. Three groups of complications (stuck-pipe or sticking, loss circulation, kick or gas-oil-water occurrence) and standard drilling operations were simulated to minimize the number of false alarms. A total of 86 experiments were modeled, which were then processed using neural network algorithms. The study revealed that the model of an artificial neural network for predicting future manifestations of complications in the form of the "kick or gas-oil-water occurrence", due to its complexity, is trained more efficiently when using not only the input values of drilling parameters, but also the output results of some auxiliary machine learning models. The latest models are trained to solve both regression problems of the indicator function with the model setting to track changes in certain parameters, and the problem of identifying abnormal situations during drilling in real time. When this module trains an artificial neural network model to detect a pre-accident situation of "kick or gas-oil-water occurrence", the following results were obtained for accuracy: accuracy – 0.89, weighted average f1-score – 0.86. The developed system informs the driller about a possible complication with high accuracy, which allows him to avoid it or minimize the consequences.
Enabling Drillstem Testing in Ansagan Field in High-Pressure, High H2S Pre Caspian Deep Wells
Authors: Burlibayev Askhat , Baishuakov Murat , Aimagambetov Marat , Kydatov Mikhail , Kaipov Yermek , Kumar Pramod , Akbayev Beibit 
Published: October 2020

Abstract
Pre-salt carbonates in the Pre-Caspian Basin have prolific hydrocarbon-bearing formations onshore and offshore. Recent exploration wells more than 5000 m deep in the region have had limited success, mostly due to challenging conditions for well testing. This paper summarizes key elements of one of the first successful drill stem testing (DST) campaigns in Ansagan Field.
The holistic DST design for Ansagan field addressed perforating methods, brine selection, packer and DST equipments material selection for hostile environment with high-pressure, high-H2S fluids, and corrosive acid to be used for stimulation. The surface equipment design had to reliably control the well, separate fluids, measure flow rates, and dispose hydrocarbons with minimum environmental impact. Surface flow rate measurement combined of a multiphase flowmeter and three-phase separator. Downhole samples were collected with a single-phase reservoir fluid sampler.
Calcium & zinc bromide brine with 1.77-SG density proved effective. The specially modified completion packer design was in the well up to 6 months and was successfully retrieved after the test.
Although perforating in these deep high pressure wells was usually performed on wireline, accurate shock prediction and design adjustments managed the risk for using tubing-conveyed perforating (TCP) to perforate large intervals in underbalance conditions allowing to achieve lower skin, and flow the well immediately.
The DST string enabled performing production logging, downhole fluid sampling, and acid stimulation with coiled tubing. Fluid sampling was performed on wireline to preserve gas condensate components at reservoir conditions. The highly accurate memory gauges, real-time operations, and reservoir engineer's support made it possible to acquire accurate data to characterize the fracture distribution, which is vital information in fractured carbonates.
In summary, three wells have been successfully tested with a total of 16 zones at Ansagan field, achieving all well test objectives.
Field Case: Complex Water Inflow Risk Evaluation by Various Surveillance Methods
Authors: Skopich Anton , Neubauer Edward , Sadyrbakiyev Renat , Xing Lingbo 
Published: October 2020

Abstract
Complex surveillance to assess the water inflow risk of a well with an openhole completion in a fractured carbonate reservoir using temperature and geochemistry.
The production rate on the subject well was constrained to mitigate the risk of water production from a lower interval in the naturally fractured carbonate reservoir. Due to a wellbore restriction a production log could not be run to help diagnose the risk of the water inflow. Temperature from the permanent downhole gauge (PDHG) was used to estimate the inflow interval and geochemistry of production oil was used to evaluate the water inflow risk.
The analysis of temperature from the permanent downhole gauge indicated that production was coming from the shallower water free interval. Geochemistry using HRGC (High Resolution Gas Chromatography) and LTM-GC (Low Thermal Mass Gas Chromatograph) analysis was used to assess if the wellbore was connected to the lower wet interval through the fracture network. If the wellbore was not connected to the fracture network, the production constraint could be removed, and the rate increased by approximately 6000 STBPD. The production rate was increased in stages with periodic oil sampling and HRGC analysis to check for a water washing signature which would indicate inflow from the lower wet interval. The well was successfully ramped-up and is still producing water free.
In the absence of production log (PLT) data and a clear difference in fingerprinting signature between producing Units, Oil Geochemistry was used to differentiate producing intervals due to water wash effect of the produced oil signature.
An Integrated Approach to Well Integrity Diagnostics Utilizing Next Generation Passive Acoustic Logging Technology
Authors: Atakishiyev Fuad , Ramazanov Rizvan , Allan Fergus , Zett Adrian , Graham Tom , Imrie Andrew , Tracadas Philip , Mirzayev Kamil 
Published: October 2020

Abstract
To ensure the continuation of safe and reliable well operations diagnosing well health issues becomes increasingly necessary. Having access to the right technology can provide greater confidence in diagnostics data; enabling more effective well management and risk mitigation. As a prudent operator, bp is proactive and rigorous in monitoring the health of its well stock and is continuously introducing new technology and methods to increase the effectiveness of its surveillance capabilities.
Traditionally, a combination of passive acoustics and temperature has been deployed in such investigations, but historically this has yielded limited success in offshore wells due to the combination of complex overprints. Whilst it is still acknowledged that passive acoustic logging does have limitations, chiefly due to their inability to characterize sporadic signals, next generation passive acoustics technology equipped with spectral sensor arrays have significantly enhanced abilities to measure subtle acoustic signals. This paper details an approach utilized offshore Azerbaijan for such diagnostics work, using these latest passive acoustic technologies, teamed with conventional temperature and distributed fibre optics.
As part of routine and ongoing data gathering, different tools were tested across a multi-well campaign in a variety of environments and different well states; static, active annular bleed and whilst applying pressure to annuli. Previous logging programs have deployed passive acoustic tools to confirm pre-existing notions of well issues. The logging programs described in this paper used higher sample densities and longer station intervals to enable a detailed and objective view of well health. There were thousands of stations acquired in more than 10 runs across production, water and gas injector wells. The acquired dataset generated a vast number of data points across different fluid types, completions and well conditions which allowed a more robust assessment of tool repeatability, sensitivity and spectral response. Highly sensitive hydrophones in modern spectral passive acoustic logging tools along with temperature and fibre measurements integrated with other information helped our understanding of the dynamics behind the casing, allowing us to make better informed decisions about wells operations.
As the datasets grew in size, quick-look processing methodology was developed to identify and characterize acoustic anomalies. The paper will demonstrate how the techniques developed have generated more confidence in passive acoustic technology. It will show how both acquisition procedures and data processing techniques were optimized to ensure the best quality answer products were delivered.
Numerical Calculation of the Pressure Drop and Saturation of Two-Phase Flow Through Porous Medium
Authors: Akasheva Zhibek , Assilbekov Bakhytzhan , Kudaikulov Aziz , Bolysbek Darezhat 
Published: October 2020

Abstract
Two-phase flow through a fibrous porous medium is numerically simulated. The goal of the study is to investigate the effect of numerical slip length on variation of pressure drop and saturation.
The simulation is based on the numerical solution of incompressible Navier-Stokes equations for two-phase flow around a circular cylinder with radii in the ranges from 0.1 to 0.4. Variations of pressure drop and saturation in time are numerically calculated on simple and snap meshes for different values of surface tension (σ), viscosity ratio (M = μnw/μw), and mesh sizes. Also, numerical results using simple and snap meshes are compared. Numerical calculations are performed using the interFoam solver in OpenFOAM® finite volume library.
The presented results show that solutions of saturation and pressure drop in time vary with mesh refinement, so the numerical slip length significantly affects the flow. For a coarser mesh the influence of numerical slip length is less than for a finer mesh, also as bigger the value of the viscosity ratio or surface tension as lower the influence of numerical slip length. The results show that the contact line motion significantly depends not only on the microstructure of the porous media, but also on the fluid properties (viscosity ratio, surface tension and etc.).
Pregnancy outcomes of Chinese women undergoing IVF with embryonic cryopreservation as compared to natural conception
Authors: Wang Jingxue , Liu Qiwei , Deng Boer , Chen Fang , Liu Xiaowei , Cheng Jiumei 
Published: October 2020

Abstract
Background: To examine differences in the maternal characteristics and pregnancy outcomes of Chinese women with various causes of infertility who underwent in vitro fertilization (IVF) with embryonic cryopreservation treatment.Methods: Cases were pregnancies after IVF-ET with embryonic cryopreservation; controls were spontaneously conceived pregnancies. Subgroup analysis was carried out according to etiology of infertility. The IVF treatment group was divided into 5 subgroups according to infertility etiology as follows: ovulation disorder, tubal disease, male infertility, endometriosis, and mixed infertility. Data on demographic characteristics, medical history, laboratory tests, and delivery were reviewed. Logistic regression analysis was performed for pregnancy and perinatal complications and neonatal outcomes. The multivariable model was adjusted for potential confounders.Results: Among singleton pregnancies, compared with spontaneous pregnancies, IVF pregnancies were associated with significant increases in the rates of the following: gestational diabetes mellitus (GDM) (aOR 1.76[95% CI 1.33-2.33]), preeclampsia (2.60[1.61-4.20]), preterm preeclampsia (4.52[2.03-10.06]), postpartum hemorrhage (1.57[1.04-2.36]), intrahepatic cholestasis of pregnancy (3.84[1.06-13.94]), preterm premature rupture of membranes (2.11[1.17-3.81]), preterm birth (1.95[CI 1.26-3.01]), low birthweight (1.90[1.13-3.20]), macrosomia (1.53[1.03-2.27]), and neonatal intensive care unit (NICU) admission (1.69[1.22-2.34]) in the ovulation disorder group; GDM (1.50[1.21-1.86]), placenta previa (2.70[1.59-4.59]), placenta accreta (1.78[1.10-2.89]), postpartum hemorrhage (1.61[1.19-2.18]), macrosomia (1.60[1.21-2.13]) and 5-minute Apgar score ≤7 (4.09[1.04-16.08]) in the tubal disease group; placenta previa (9.33[4.22-20.62]), small for gestational age (2.29[1.04-5.08]), macrosomia (2.00[1.02-3.95]) and NICU admission (2.35[1.35-4.09]) in the endometriosis group; placenta previa (4.14[2.23-7.68]) and placenta accreta (2.05[1.08-3.87]) in the male infertility group; and GDM (1.85[1.15-2.98]), placenta previa (4.73[1.83-12.21]), placental abruption (3.39[1.20-9.56]), chorioamnionitis (2.93[1.04-8.26]), preterm birth (2.69[1.41-5.15]), and 1-minute Apgar score ≤7 (4.68[1.62-13.51]) in the mixed infertility group. Among multiple pregnancies, most of the differences that were significant in singleton pregnancies were less extensive or had disappeared.Conclusions: Infertility etiology within the IVF population was found to affect maternal and neonatal outcomes among all births. During the perinatal period, infertility etiology appears to be an additional risk factor for abnormal pregnancy outcomes besides the use of IVF techniques compared with spontaneous pregnancies. Higher risk was found for ovulation disorders, and lower risk was found for male infertility.
Effects of social support, hope and resilience on depressive symptoms within 18 months after diagnosis of prostate cancer
Authors: Zhao Xinxin , Sun Ming , Yang Ye 
Published: October 2020

Abstract
Background: The prevalence of depression symptoms and related modifiable factors in prostate cancer (PCa) are not well evaluated. We aimed to assess the effects of perceived social support, hope and resilience on depressive symptoms within 18 months after diagnosis of PCa, and to evaluate the role of hope and resilience as mediators of that relationship.Method: A cross-sectional study was analyzed in consecutive inpatients with PCa during the months of January 2018 and August 2019. A questionnaire was administered to 667 patients. All registered patients were all volunteers and anonymous. Depressive symptoms, perceived social support, hope and resilience were measured anonymously. Out of 667 patients, a total of 564 effective respondents (< 30% missing data) became our subjects. Hierarchical linear regression was used to identify the factors associated with depressive symptoms. Asymptotic and resampling strategies were used to conduct the mediating effects of hope and resilienceResults: The prevalence of depressive symptoms was 65.9% in PCa patients. Hierarchical regression analyses indicated that perceived social support, hope, and resilience together accounted for 27.5% variance of depressive symptoms. Support from family, hope, and resilience significantly associated with depressive symptoms, respectively. Hope (a*b = -0.0783, BCa95% CI:-0.134 to -0.0319, p < 0.05), and resilience (a*b = -0.1315, BCa95% CI:-0.1894 to -0.0783, p < 0.05) significantly mediated the association between perceived social support and depressive symptoms.Conclusions: The high prevalence of depressive symptoms among PCa patients should receive more attention. Perceived social support, hope and resilience could be positive resources for combating depressive symptoms, and hope and resilience mediated the association between perceived social support and depressive symptoms. Enhancing social support, particularly the support form family, and improving patients’ outlook and resilience may be potential targets for future psychosocial interventions aimed at reducing depressive symptoms.
Co-relation with novel phosphorylation sites of IκBα and necroptosis in breast cancer cells
Authors: Choi Sung Hoon , Chung Young Ho , Yoon Hee-sub , Yoo Shin-ae , Yun Sung Ho , Park Joo-Hee , Han Eun Hee , Chi Sung-Gil 
Published: October 2020

Abstract
Background: Phosphorylation of NF-kappaB inhibitor alpha (IκBα) is key to regulation of NF-κB transcription factor activity in the cell. Several sites of IκBα phosphorylation by members of the IκB kinase family have been identified, but phosphorylation of the protein by other kinases remains poorly understood. We investigated a new phosphorylation site on IκBα and identified its biological function in breast cancer cells.Methods: Previously, we observed that aurora kinase (AURK) binds IκBα in the cell. To identify the domains of IκBα essential for phosphorylation by AURK, we performed kinase assays with a series of IκBα truncation mutants. AURK significantly promoted activation of IκBα at serine 32 but not serine 36; by contrast, IκB kinase (IKK) family proteins activated both of these residues. We also confirmed phosphorylation of IκBα by matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/TOF MS) and nano-liquid chromatography hybrid quadrupole orbitrap mass spectrometer (nanoLC-MS/MS; Q-Exactive).Results: We identified two novel sites of serine phosphorylation, S63 and S262. Alanine substitution of S63 and S262 (S63A and S262A) of IκBα inhibited proliferation and suppressed p65 transcription activity. In addition, S63A and/or S262A of IκBα regulated apoptotic and necroptotic effects in breast cancer cells.Conclusions: Phosphorylation of IκBα by AURK at novel sites is related to the apoptosis and necroptosis pathways in breast cancer cells.
Bone Marrow Mesenchymal Stem Cell-derived Exosomes Promote Plasminogen Activator Inhibitor 1 Expression in Vascular Cells in the Local Microenvironment During Rabbit Osteonecrosis of the Femoral Head
Authors: Li Lu , Wang Yikai , Yu Xiaobing , Bao Yongming , An Lijia , Wei Xiaowei , Yu Weiting , Liu Baoyi , Li Junlei , Yang Jiahui , Xia Yan , Liu Ge , Cao Fang , Zhang Xiuzhi , Zhao Dewei 
Published: October 2020

Abstract
Background: Nontraumatic osteonecrosis of the femoral head (NONFH) is a highly disabling orthopedic disease in young individuals. Plasminogen activator inhibitor 1 (PAI-1) has been reported to be positively associated with NONFH. We aimed to investigate the dysregulating PAI-1 in bone marrow mesenchymal stem cells (BMMSCs) and vascular cells in rabbit steroid-induced NONFH. Methods: To verify the hypothesis that BMMSCs could promote thrombus formation in a paracrine manner, we collected exosomes from glucocorticoid-treated BMMSCs (GB-Exo) to determine their regulatory effects on vascular cells. microRNA sequencing was conducted to find potential regulators in GB-Exo. Utilizing gain-of-function and knockdown approaches, we testified regulatory effect of microRNA in exosomes.Results: The expression of PAI-1 was significantly increased in local microenvironment of the femoral head in ONFH model. GB-Exo promoted PAI-1 expression in vascular smooth muscle cells and vascular endothelial cells. We also revealed that miR-451-5p in GB-Exo plays a crucial role for the elevated PAI-1. Moreover, we identified miR-133b-3p and tested its role as a potential inhibitor of PAI-1. Conclusions: This study provided considerable evidence for BMMSC exosomal miR-mediated upregulation of the fibrinolytic regulators PAI-1 in vascular cells. The disruption of coagulation and low fibrinolysis in the femoral head will eventually lead to a disturbance in microcirculation of NONFH. We believe that our findings could be of great significance for guiding clinical trials in the future.
Prevalence and antimicrobial susceptibility pattern of Staphylococcus Aureus isolated from clinical specimens at the Mater Hospital Nairobi, Kenya.
Authors: Okello Christina , Achieng Loice , Mwachari Christina , Otieno Davies , Otieno Frederick , Omonge Enoch 
Published: October 2020

Abstract
Staphylococcus aureus is a leading cause of hospital and community acquired infections globally. Surveillance of prevalence and antibiotic susceptibility patterns is important to ensure appropriate antibiotic prescription. The aim of this study was to determine the prevalence and susceptibility patterns of Staphylococcus aureus isolated from clinical specimens in a tertiary referral and training hospital.A retrospective study was conducted at the Mater Misericordiae Hospital, Nairobi.It involved analyzing records of specimens analyzed between January 2014 and December 2018. Strains phenotypically resistant to <3 non β-lactam antimicrobial categories were defined as non-multidrug-resistant MRSA (nmMRSA) and strains that were resistant to ≥3 non-β-lactam antimicrobial groups were defined as multidrug-resistant MRSA (mMRSA). A specimen was categorized as Penicillin susceptible (PSSA) if susceptible to Penicillin and Oxacillin, MSSA if resistant to Penicillin and susceptible to Oxacillin, and MRSA if resistant to Oxacillin and Penicillin.ResultsPSSA accounted for 60.85%, (401/659)of S.aureus cultured.The prevalence of MSSA was 38.54%(254/659).MRSA was the least prevalent.(0.61%,4/659).No multi-drug Methicillin resistant S. aureus were isolated in the five-year period.PSSA accounted for 60.85%(401/659)of all S.aureus isolates.100% of MRSA isolated was sensitive to Vancomycin, Linezolid, Tigecycline, Tetracycline and Rifampicin. MRSA was resistant to Clindamycin and Erythromycin.Conclusion;The prevalence of MRSA was low compared to previous studies.All strains isolated were non-multidrug resistant.There was no resistance to Vancomycin detected.Penicillins are still a viable option in the treatment of majority of S.aureus infections in our setting.