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Root cause of sand production and methodologies for prediction

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Petroleum 2021年第3期7卷 263-271页

作者： Surej Kumar Subbiah Arifin Samsuri assef mohamad-hussein Mohd Zaidi Jaafar Ying Ru Chen Rajeev Ranjan Kumar Department of Petroleum Engineering Faculty of EngineeringUniversiti Teknologi MalaysiaMalaysia Schlumberger GatwickUnited Kingdom Schlumberger DohaQatar Schlumberger MumbaiIndia

The consequences of sandstone reservoir rock failure may lead to sand *** phenomenon can have negative impact on lifting cost and economic of any field *** erosion due to sanding can lead to loss of integrity and hydrocarbon *** decision on the type of completion can risk the viability of the *** facilitate best sand management over the life of a field and to maintain economical productivity,accurate prediction of sand production volume/rates is needed to increase both productivity and the ultimate recovery of the hydrocarbon while keeping the operating cost *** paper summarizes the sand production modeling for onset and volume of sand namely technology that required to improve understanding on sand production and *** main questions will be answered,why industry needs to worry about sand production,what are the available technologies to predict sanding volume/rates finally,how the current technologies can be improved to estimate sand production volume/rates.

关键词： Sand production Sanding rates Geomechanics Sand control Constitutive model Failure criteria

Geomechanical modelling of cold heavy oil production with sand

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Petroleum 2022年第1期8卷 66-83页

作者： assef mohamad-hussein Pablo Enrique Vargas Mendoza Paolo Francesco Delbosco Claudia Sorgi Vincenzo De Gennaro Surej Kumar Subbiah Qinglai Ni Jose Maria Segura Serra MRLakshmikantha Jos Alvarellos Iglesias Rebecca Daniels Schlumberger Geomechanics Center of Excellence Gatwick AirportUnited Kingdom Schlumberger Calle Alvarez de Baena 4Planta Baja28006MadridSpain Schlumberger Av.A.NobelZI NordPau64000France Schlumberger 45th Floor Tornado TowerWest BayMajlis Al TaawonDohaQatar Repsol Technology Center MostolesMadridSpain

The contribution of geomechanics to provide a rigorous quantification of porosity changes and associated permeability changes is often neglected when considering hydrocarbon ***,it often has significant effects on production rates and ultimate *** the cold heavy oil production with sand(CHOPS)technique,geomechanics is the key for reservoir simulations and promoting successful *** fact,the technique employed in CHOPS significantly affects the stress state within the reservoir by inducing“on-purpose”formation *** is not only vital to comprehend the behaviour of the reservoir during production,but it is crucial to identify how to harness that behaviour to improve *** order to simulate the mechanical behaviour of unconsolidated sand material,an elastoplastic damage model was ***-flow-geomechanical modelling was then performed for predicting individual well behaviour and overall field *** combined effect of fluid-flow and geomechanics improved predictions with respect to oil,water,and gas production rates at key *** rates matched satisfactorily most of the *** addition,the onset and propagation of equivalent wormhole networks were quantified throughout the production *** enabled quantification of the volume of produced sand at individual *** comparisons between the measured and simulated sand volume rate at well locations showed reasonable *** calibrated models can then be used for the placement of new wells to optimize production.

关键词： CHOPS Numerical simulation Sanding Geomechanics

Improving Deep Attractor Network by BGRU and GMM for Speech Separation

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Journal of Harbin Institute of Technology(New Series) 2021年第3期28卷 90-96页

作者： Rawad Melhem assef Jafar Riad Hamadeh Higher Institute for Applied Sciences and Technology DamascusSyria

Deep Attractor Network(DANet) is the state-of-the-art technique in speech separation field, which uses Bidirectional Long Short-Term Memory(BLSTM), but the complexity of the DANet model is very high. In this paper, a simplified and powerful DANet model is proposed using Bidirectional Gated neural network(BGRU) instead of BLSTM. The Gaussian Mixture Model(GMM) other than the k-means was applied in DANet as a clustering algorithm to reduce the complexity and increase the learning speed and accuracy. The metrics used in this paper are Signal to Distortion Ratio(SDR), Signal to Interference Ratio(SIR), Signal to Artifact Ratio(SAR), and Perceptual Evaluation Speech Quality(PESQ) score. Two speaker mixture datasets from TIMIT corpus were prepared to evaluate the proposed model, and the system achieved 12.3 dB and 2.94 for SDR and PESQ scores respectively, which were better than the original DANet model. Other improvements were 20.7% and 17.9% in the number of parameters and time training respectively. The model was applied on mixed Arabic speech signals and the results were better than that in English.

关键词： attractor network speech separation gated recurrent units

Hydroethanolic extract of Smallanthus sonchifolius leaves improves hyperglycemia of streptozotocin induced neonatal diabetic rats

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Asian Pacific Journal of Tropical Medicine 2016年第5期9卷 420-424页

作者： Silmara Baroni Bruno Ambrosio da Rocha Juliana Oliveira de Melo Jurandir Fernando Comar Silvana Martins Caparroz-assef Ciomar Aparecida Bersani-Amado Department of Pharmacology and Therapeutic State University of MaringaParanaBrazil Department of Biochemistry State University of MaringaParanaBrazil

Objective: To evaluate the effect of hydroethanolic extract of yacon on the hyperglycemia induced by streptozotocin(STZ) in neonatal rats. Methods: Wistar rats aged two days old received an intraperitoneal injection of STZ(160 mg/kg); after seven weeks, glycosuria was determined and animals with glucose levels above 250 mg/d L were included in the study. Groups of diabetic and non-diabetic rats were treated orally with yacon extract at a dose of 400 mg/kg/d for 14 d. Tests were made for phytochemical characterization, glucose tolerance and toxicity. Results: The results showed that treatment with the extract reduced the glucose levels of fed diabetic rats and did not change the glucose levels of fasting diabetic and normal rats. Additionally, also it was observed that treatment with the extract reduced blood glucose levels of diabetic rats during the oral and intravenous glucose tolerance tests. There was no change in body weight, liver enzymes or mortality with yacon extract treatment. The phytochemical screening revealed the presence of caffeic acid, chlorogenic acid, ferulic acid and gallic acid. Conclusions: The data suggest that yacon extract reduces hyperglycemia, possibly by improving insulin sensibility through its phytochemicals constituents(phenolic compounds).

关键词： Yacon extract Hyperglycemia Insulin sensibility Streptozotocin

Acute pancreatitis complicated with splenic rupture: A case report

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World Journal of Gastrointestinal Surgery 2015年第9期7卷 219-222页

作者： Bruno L Hernani Pedro C Silva Ricardo T Nishio Henrique C Mateus José C assef Tercio De Campos Irmandade da Santa Casa de Misericórdia de Sao Paulo Hospital Santa Casa School of Medicine Department of Surgery Emergency UnitIrmandade da Santa Casa de Sao Paulo HospitalSanta Casa School of Medicine

Atraumatic splenic rupture is an uncommon complication of acute pancreatitis. This report describes the case of a 30-year-old man with acute pancreatitis and splenic vein thrombosis complicated by splenic rupture. The patient was admitted to the emergency department with pain in the upper abdomen that had been present for six hours and was associated with vomiting and sweating. He was diagnosed with acute pancreatitis of alcoholic etiology. Upon computed tomography(CT) of the abdomen, the pancreatitis was scored as Balthazar C grade, and a suspicious area of necrosis affecting 30% of the pancreas with splenic vein thrombosis was revealed. Seventytwo hours after admission, the patient had significant improvement in symptoms. However, he showed clinical worsening on the sixth day of hospitalization, with increasing abdominal distension and reduced hemoglobin levels. A CT angiography showed a large amount of free fluid in the abdominal cavity, along with a large splenic hematoma and contrast extravasation along the spleen artery. The patient subsequently underwent laparotomy, which showed hemoperitoneum due to rupture of the splenic parenchyma. A splenectomy was then performed, followed by ultrasound-guided percutaneous drainage.

关键词： Acute pancreatitis Pancreatitis Rupture Splenic rupture Spontaneous

Improving Deep Attractor Network by BGRU and GMM for Speech Separation

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Reliability in endoscopic diagnosis of portal hypertensive gastropathy

哈尔滨工业大学学报（英文版） 2021年第3期

作者： Rawad Melhem assef Jafar Riad Hamadeh

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World Journal of Gastrointestinal Endoscopy 2013年第7期5卷 323-331页

作者： George Fred Soares de Macedo Fabio Gon alves Ferreira Maurício Alves Ribeiro Luiz Arnaldo Szutan Mauricio Saab assef Lucio Giovanni Battista Rossini Endoscopy Service Santa Casa de So Paulo Medical SchoolSo Paulo 01221-900 Brazil Department of Surgery Liver and Portal Hypertension Unit Santa Casa de So Paulo Medical SchoolSo Paulo 01221-900 Brazil

AIM: To analyze reliability among endoscopists in diagnosing portal hypertensive gastropathy (PHG) and to determine which criteria from the most utilized classifications are the most suitable. METHODS: From January to July 2009, in an academic quaternary referral center at Santa Casa of S o Paulo Endoscopy Service, Brazil, we performed this singlecenter prospective study. In this period, we included 100 patients, including 50 sequential patients who had portal hypertension of various etiologies; who were previously diagnosed based on clinical, laboratory and imaging exams; and who presented with esophageal varices. In addition, our study included 50 sequentialpatients who had dyspeptic symptoms and were referred for upper digestive endoscopy without portal hypertension. All subjects underwent upper digestive endoscopy, and the images of the exam were digitally recorded. Five endoscopists with more than 15 years of experience answered an electronic questionnaire, which included endoscopic criteria from the 3 most commonly used Portal Hypertensive Gastropathy classifications (McCormack, NIEC and Baveno) and the presence of elevated or flat antral erosive gastritis. All five endosco- pists were blinded to the patients' clinical information, and all images of varices were deliberately excluded for the analysis. RESULTS: The three most common etiologies of portal hypertension were schistosomiasis (36%), alcoholic cirrhosis (20%) and viral cirrhosis (14%). Of the 50 patients with portal hypertension, 84% were Child A, 12% were Child B, 4% were Child C, 64% exhibited previous variceal bleeding and 66% were previously endoscopic treated. The endoscopic parameters, presence or absence of mosaic-like pattern, red point lesions and cherry-red spots were associated with high inter-observer reliability and high specificity for diagnosing Portal Hypertensive Gastropathy. Sensitivity, specificity and reliability for the diagnosis of PHG (%) were as follows: mosaic-like pattern (10

关键词： Endoscopy Cirrhosis Portal hypertension Portal hypertensive gastropathy Stomach