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Relevant bibliographies by topics / Wells-Score

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Academic literature on the topic 'Wells-Score'

Author: Grafiati

Published: 4 June 2021

Last updated: 11 February 2022

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Journal articles on the topic "Wells-Score"

1

Abdelaal Ahmed Mahmoud M. Alkhatip, Ahmed, Maria Donnelly, Lindi Snyman, Patrick Conroy, Mohamed Khaled Hamza, Ian Murphy, Andrew Purcell, and David McGuire. "YEARS Algorithm Versus Wells’ Score." Critical Care Medicine 48, no. 5 (May 2020): 704–8. http://dx.doi.org/10.1097/ccm.0000000000004271.

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Abdel Kerim, Yasser. "AKT question relating to Wells score." InnovAiT: Education and inspiration for general practice 13, no. 6 (May 15, 2020): 343. http://dx.doi.org/10.1177/1755738020913216.

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Hasanoğlu, Canan, Emine Argüder, Hatice Kılıç, Ebru Sengul Parlak, and Ayşegül Karalezli. "Atrial fibrillation, an obscured cause of pulmonary embolism can be revealed by adding to Wells criteria." Journal of Investigative Medicine 67, no. 7 (May 7, 2019): 1042–47. http://dx.doi.org/10.1136/jim-2018-000914.

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Among the various clinical scoring methods used for the prediagnosis of pulmonary embolism (PE), Wells criteria is the most common. It relies on the findings and story of deep venous thrombosis (DVT), PE and malignancy. It is known that atrial fibrillation (AF) is a risk factor for PE like as DVT or malignancy. We aimed to evaluate the possibility of diagnosing more patients with PE by including AF in the Wells criteria. This prospective study included 250 patients admitted to the emergency department with PE findings. Wells scoring and Wells scoring with AF were performed for each patient. Out of 250 patients, 165 patients were diagnosed as PE. Wells score was >4 in 61.8% of patients with PE and 28.2% of patients without PE. Out of false negative 63 patients with PE, 21 of them had AF. According to Wells scoring with AF the score of 148 (89.7%) patients with PE diagnosis was ≥3, whereas the score of 45 (52.9%) patients without PE was ≥3. AF was detected in 15.8% of patients with PE. The sensitivity of Wells score with AF was significantly higher than that of the Wells score (p<0.001). As a result, when AF, which is one of an important PE cause such as DVT and malignancy, was added to the Wells criteria, an additional correct PE estimate was obtained in 46 patients. We recommend using Wells score with AF since prediagnosing more PE is more valuable than having some false negative PE predictions.

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Price, Erika Leemann, and Tracy Minichiello. "The Wells Deep Vein Thrombosis Score for Inpatients." JAMA Internal Medicine 175, no. 7 (July 1, 2015): 1118. http://dx.doi.org/10.1001/jamainternmed.2015.1699.

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Pommer, P. "Tiefe Beinvenenthrombose: Wells-Score zum Ausschluss meist geeignet." DMW - Deutsche Medizinische Wochenschrift 139, no. 18 (April 23, 2014): 926. http://dx.doi.org/10.1055/s-0034-1372256.

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Girardi, Adriana M., Renata S. Bettiol, Tiago S. Garcia, Gustavo L. H. Ribeiro, Édison Moraes Rodrigues, Marcelo B. Gazzana, and Tatiana H. Rech. "Wells and Geneva Scores Are Not Reliable Predictors of Pulmonary Embolism in Critically Ill Patients: A Retrospective Study." Journal of Intensive Care Medicine 35, no. 10 (December 16, 2018): 1112–17. http://dx.doi.org/10.1177/0885066618816280.

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Background: Critically ill patients are at high risk for pulmonary embolism (PE). Specific PE prediction rules have not been validated in this population. The present study assessed the Wells and revised Geneva scoring systems as predictors of PE in critically ill patients. Methods: Pulmonary computed tomographic angiograms (CTAs) performed for suspected PE in critically ill adult patients were retrospectively identified. Wells and revised Geneva scores were calculated based on information from medical records. The reliability of both scores as predictors of PE was determined using receiver operating characteristic (ROC) curve analysis. Results: Of 138 patients, 42 (30.4%) were positive for PE based on pulmonary CTA. Mean Wells score was 4.3 (3.5) in patients with PE versus 2.7 (1.9) in patients without PE ( P < .001). Revised Geneva score was 5.8 (3.3) versus 5.1 (2.5) in patients with versus without PE ( P = .194). According to the Wells and revised Geneva scores, 56 (40.6%) patients and 49 (35.5%) patients, respectively, were considered as low probability for PE. Of those considered as low risk by the Wells score, 15 (26.8%) had filling defects on CTA, including 2 patients with main pulmonary artery embolism. The area under the ROC curve was 0.634 for the Wells score and 0.546 for the revised Geneva score. Wells score >4 had a sensitivity of 40%, specificity of 87%, positive predictive value of 59%, and negative predictive value of 77% to predict risk of PE. Conclusions: In this population of critically ill patients, Wells and revised Geneva scores were not reliable predictors of PE.

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Sermsathanasawadi, N., P. Suparatchatpun, T. Pumpuang, K. Hongku, K. Chinsakchai, C. Wongwanit, C. Ruangsetakit, and P. Mutirangura. "Comparison of clinical prediction scores for the diagnosis of deep vein thrombosis in unselected population of outpatients and inpatients." Phlebology: The Journal of Venous Disease 30, no. 7 (June 25, 2014): 469–74. http://dx.doi.org/10.1177/0268355514541981.

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Objectives The aim of this research was to compare the accuracy of the modified Wells, the Wells, the Kahn, the St. André, and the Constans score for the diagnosis of deep vein thrombosis of the lower limb in unselected population of outpatients and inpatients. Method The pretest of probability score was employed in consecutive 500 outpatients and inpatients with suspicion of deep vein thrombosis. All patients were examined with compression ultrasonography. Results Deep vein thrombosis was confirmed in 26.4%. In the unselected population of outpatients and inpatients, the accuracy of the modified Wells score and the Constans score was higher than other scores. Both scores were more accurate for the outpatients. There was no accurate score for the inpatient subgroup. Conclusions The modified Wells and the Constans score appear to be useful in the unselected population of outpatients and inpatients and particularly in the outpatient subgroup.

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Palanisamy, Dhanaraj, and Akshay Omkumar. "A study on the effectiveness of wells criteria for diagnosing deep vein thrombosis: a prospective observational study." International Surgery Journal 8, no. 2 (January 29, 2021): 569. http://dx.doi.org/10.18203/2349-2902.isj20210365.

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Background: Wells score which takes into account various aspects in the history as well as various clinical signs which can help the clinician to arrive at a diagnosis of deep vein thrombosis (DVT). This helps to save time and money that is wasted in doing many unnecessary investigations. Aim of the study was to test the application of the Wells score in our clinical set up and to see how effectively we can diagnose DVT.Methods: This was a prospective diagnostic validation study of the wells rule for DVT in our setup, ultrasound (USG) being the gold standard comparison and will be conducted over a duration of 12 months. Wells score for each patient was calculated and the results were evaluated.Results: Among the 50 cases suspected DVT, the wells score was able to predict DVT in 46 of the cases thus proving to be a very efficient diagnostic indicator. The average wells score among the various cases was 4/8. Complications noted in the study group were 2 cases of cortical vein thrombosis in the post-partum period which fully recovered. Mortality rate in the study group was 4.3% in which a single case of diagnosed myocardial infarction died of heart failure.Conclusions: Wells score is indeed a very good predictive criteria for DVT and can be applied with ease as it required only clinical assessment and thus avoids unnecessary delays in waiting for scans thereby allowing us to start anticoagulants as early as possible.

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Rahiminejad, Maryam, Anshul Rastogi, Shirish Prabhudesai, David Mcclinton, Peter MacCallum, Sean Platton, and Emma Friedman. "Evaluating the Use of a Negative D-Dimer and Modified Low Wells Score in Excluding above Knee Deep Venous Thrombosis in an Outpatient Population, Assessing Need for Diagnostic Ultrasound." ISRN Radiology 2014 (March 9, 2014): 1–5. http://dx.doi.org/10.1155/2014/519875.

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Aims. Colour doppler ultrasonography (CDUS) is widely used in the diagnosis of deep venous thrombosis (DVT); however, the number of scans positive for above knee DVT is low. The present study evaluates the reliability of the D-dimer test combined with a clinical probability score (Wells score) in ruling out an above knee DVT and identifying patients who do not need a CDUS. Materials and Method. This study is a retrospective audit and reaudit of a total of 816 outpatients presenting with suspected lower limb DVT from March 2009 to March 2010 and from September 2011 to February 2012. Following the initial audit, a revised clinical diagnostic pathway was implemented. Results. In our initial audit, seven patients (4.9%) with a negative D-dimer and a low Wells score had a DVT. On review, all seven had a risk factor identified that was not included in the Wells score. No patient with negative D-dimer and low Wells score with no extra clinical risk factor had a DVT on CDUS (negative predictive value 100%). A reaudit confirmed adherence to our revised clinical diagnostic pathway. Conclusions. A negative D-dimer together with a low Wells score and no risk factors effectively excludes a lower limb DVT and an ultrasound is unnecessary in these patients.

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Bublak, Robert. "Mit Wells-Score und D-Dimer-Test Lungenembolien ausschließen." MMW - Fortschritte der Medizin 154, no. 19 (November 2012): 7. http://dx.doi.org/10.1007/s15006-012-1315-5.

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Dissertations / Theses on the topic "Wells-Score"

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Ayad, Nadia [Verfasser], Holger [Akademischer Betreuer] Hänßle, Claudia [Akademischer Betreuer] Dellas, and Thomas [Akademischer Betreuer] Crozier. "Der diagnostische Wert von Wells-Score und D-Dimer-Test bei stationären Patienten mit dermatologischen Krankheitsbildern zum Ausschluss oder zur Bestätigung einer Tiefvenenthrombose / Nadia Ayad. Gutachter: Claudia Dellas ; Thomas Crozier. Betreuer: Holger Hänßle." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2013. http://d-nb.info/1044307234/34.

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Ayad, Nadia Verfasser], Holger [Akademischer Betreuer] Hänßle, Claudia [Akademischer Betreuer] [Dellas, and Thomas [Akademischer Betreuer] Crozier. "Der diagnostische Wert von Wells-Score und D-Dimer-Test bei stationären Patienten mit dermatologischen Krankheitsbildern zum Ausschluss oder zur Bestätigung einer Tiefvenenthrombose / Nadia Ayad. Gutachter: Claudia Dellas ; Thomas Crozier. Betreuer: Holger Hänßle." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2013. http://nbn-resolving.de/urn:nbn:de:gbv:7-11858/00-1735-0000-001A-E608-2-3.

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Ayad, Nadia. "Der diagnostische Wert von Wells-Score und D-Dimer-Test bei stationären Patienten mit dermatologischen Krankheitsbildern zum Ausschluss oder zur Bestätigung einer Tiefvenenthrombose." Doctoral thesis, 2013. http://hdl.handle.net/11858/00-1735-0000-001A-E608-2.

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Goodier, Matthew. "Clinical utility of the modified Wells score in combination with the D-dimer assay in the prediction of deep venous thrombosis in a local population." Master's thesis, 2013. http://hdl.handle.net/10539/12301.

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Clinical prediction scores such as the modified Wells score have proved useful to determine the likelihood for the presence of lower limb deep venous thrombosis (DVT). Infection with HIV may affect the validity of this approach in the South African context. This study of 230, mostly inpatients, of which 40% were HIV positive, confirms the validity of the modified Wells score in a South African population with a high HIV seroprevalence. The score was found to be most accurate when performed within 48 hours of initiation of anticoagulation therapy and when combined with D-dimer assay result. The more widespread utilisation of this score, especially in conjunction with the D-dimer assay as part of a diagnostic algorithm will make investigation of DVT simpler and more cost effective. A diagnostic algorithm previously proven to be cost effective is suggested for adoption in local clinical practice as well as a basis for future research.

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Books on the topic "Wells-Score"

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Koczo, Agnes, Reshad Mahmud, and Belinda Rivera-Lebron. Pulmonary Embolism (DRAFT). Edited by Raghavan Murugan and Joseph M. Darby. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780190612474.003.0020.

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This chapter examines the diagnosis, risk stratification, and breadth of treatment options for pulmonary embolism (PE). It reviews the decision pathways based on degree of clinical suspicion of PE and assessing pre-test probability using the Geneva and Wells’ Score. It also reviews the Pulmonary Embolism Rule-out Criteria (PERC) and D-dimer with high negative predictive values. Imaging and cardiac biomarkers, which allow classification and risk stratification of PE, are discussed in how they guide management. Options for parenteral anticoagulation including bridging to novel oral anticoagulants or vitamin K antagonists for long term therapy are discussed, as well as clinical situations where systemic or catheter based thrombolysis should be considered. Hemodynamic support involving vasopressors are reviewed. The options for surgical embolectomy, as well as special cases including clot in transit, are discussed.

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Book chapters on the topic "Wells-Score"

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van Balen, J. A. M., A. A. Demeulemeester, M. Frölich, K. Mohrmann, L. M. Harms, W. C. H. van Helden, L. J. Mostert, and J. H. M. Souverijn. "Wells score tabe." In Memoboek, 217. Houten: Bohn Stafleu van Loghum, 2012. http://dx.doi.org/10.1007/978-90-313-9129-5_133.

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"Haematology and oncology." In Emergencies in Clinical Medicine, edited by Piers Page, Asif Shah, Greg Skinner, Alan Weir, and Natasha Eagles, 281–94. Oxford University Press, 2021. http://dx.doi.org/10.1093/med/9780198779117.003.0008.

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This chapter contains guidance on the immediate management and treatment of a number of haematological and oncological emergencies, including acute transfusion reactions, acute sickle crisis, neutropenic sepsis, deep vein thrombosis, superior vena cava obstruction, and metastatic spinal cord compression. Concise advice is given on the immediate treatment of each condition, with instructions on which tests and cultures to take, and the conditions in which it is necessary to report to the transfusion laboratory. Helpful guidelines are provided, such as the Wells score for deep vein thrombosis along with a flowchart to track the condition’s development. Further reading is provided at the end of each topic.

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Nokes, Brandon T., and Rodrigo Cartin-Ceba. "Pulmonary Embolism: An Overview." In Mayo Clinic Critical and Neurocritical Care Board Review, edited by Eelco F. M. Wijdicks, James Y. Findlay, William D. Freeman, and Ayan Sen, 142–49. Oxford University Press, 2019. http://dx.doi.org/10.1093/med/9780190862923.003.0020.

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Venous thromboembolism (VTE) is a major public health concern with an annual incidence of 1 per 1,000 patients in the United States. VTE encompasses a spectrum of diseases including deep vein thrombosis (DVT) and pulmonary embolism (PE). DVT is a precursor to PE, and approximately 80% of patients have DVT when PE is diagnosed. The risk factors for PE are the same as those for DVT; consequently, diagnosis and management of VTE are contingent on the underlying risk factors and the extent of disease. A suspected VTE diagnosis should be pursued with risk stratification tools such as the Wells DVT and PE criteria and the Revised Geneva Score for PE. This chapter reviews PE diagnosis, risk stratification, and management.

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Pruszczyk, Piotr. "Diagnosis: clinical prediction rules and laboratory tests." In ESC CardioMed, 2758–61. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780198784906.003.0658.

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Clinical manifestations of venous thromboembolism (VTE) usually are non-specific. In order to facilitate proper diagnosis, clinical prediction rules were derived. The best studied models are the Wells criteria for deep vein thrombosis and pulmonary embolism and the Geneva score for pulmonary embolism. They classify patients into different categories of clinical pretest VTE probability. Pulmonary embolism prevalence is approximately 10% in low-, 30% in moderate-, and up to 65% in high-probability categories. Plasma D-dimer levels are elevated in not only VTE but also in other conditions. A D-dimer assay should be used in combination with pretest VTE clinical probability. A normal high-sensitivity D-dimer level excludes pulmonary embolism in patients with low/intermediate or non-high VTE probability, while in the high probability category does not allow VTE to be safely excluded. Age-adjusted D-dimer thresholds (age × 10 μ‎g/L above 50 years) can limit the need for imaging methods without increasing the rate of missed diagnoses in non-high clinical probability patients.

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Becker, Richard C., and Frederick A. Spencer. "Anticoagulants." In Fibrinolytic and Antithrombotic Therapy. Oxford University Press, 2006. http://dx.doi.org/10.1093/oso/9780195155648.003.0040.

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Anticoagulant therapy, particularly when used in combination with fibrinolytics and less often platelet antagonists, can cause life-threatening hemorrhage. This supports the importance of coagulation proteases in several phases of thrombus development; paradoxically, several anticoagulants can also cause microvascular and macrovascular thrombotic disorders. Hemorrhage is the most common adverse effect associated with warfarin administration. To predict the risk of bleeding, Beyth and colleagues (1998) developed a 5-point scoring system, with 1 point given for each of the following: . . . • Age greater than 65 . . . . . . • History of stroke . . . . . . • History of gastrointestinal bleeding . . . . . . • Specific comorbid conditions (recent myocardial infarction [MI], elevated serum creatinine, hematocrit <30%, or diabetes) . . . Low-risk patients have a score of 0; intermediate-risk patients, 1 or 2; and high-risk, 3 or 4. The risk of bleeding in these three groupings at 12 months was 3%, 8%, and 30%, respectively. Many commonly used medications have significant interactions with warfarin. In 1994, Wells and colleagues (1994) reviewed all reports of warfarin–drug interactions and found original reports totaling 186. Potentiation of warfarin effect was observed with six antibiotics, five cardiac drugs, two antiinflammatory agents, two histamine2-blockers, and alcohol in persons with concomitant liver disease. Inhibition of warfarin effect was noted with three antibiotics, three central nervous system (CNS) drugs, cholestyramine, and sucralfate. An important interaction between acetaminophen and warfarin has also been recognized (Hylek et al., 1998), and certain herbal remedies, such as ginkgo biloba, ginseng, and garlic, may enhance the effects of warfarin. The first step in the management of bleeding is to stop the drug; however, recovery of clotting factor levels may take several days, depending upon the vitamin K content of the patient’s diet and rate of intrinsic metabolism. To rapidly raise coagulant factor concentrations in patients with life-threatening hemorrhage, clotting factor concentrates are given (Makris et al., 1997). The older concentrates were plasma-derived and consisted mainly of activated prothrombin complex factors. They had the disadvantages of thrombogenicity and potential for transmission of infectious agents.

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Conference papers on the topic "Wells-Score"

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Rajagopalan, R., M. Gonzalez, S. Gillenwater, and J. P. Mehta. "Retrospective Analysis Comparing Wells Score versus Revised Geneva Score in Patients Who Underwent CT Pulmonary Angiogram in the ED." In American Thoracic Society 2021 International Conference, May 14-19, 2021 - San Diego, CA. American Thoracic Society, 2021. http://dx.doi.org/10.1164/ajrccm-conference.2021.203.1_meetingabstracts.a3613.

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Patel, N., H. Eskarous, D. Sharma, and M. Krishnamurthy. "Saddle Bilateral Pulmonary Embolism in Young Athletic Male with Wells Score Zero." In American Thoracic Society 2020 International Conference, May 15-20, 2020 - Philadelphia, PA. American Thoracic Society, 2020. http://dx.doi.org/10.1164/ajrccm-conference.2020.201.1_meetingabstracts.a7264.

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Obradovic, Dusanka, Biljana Joves Sevic, Uros Batranovic, and Rada Tesic. "Correlation between Wells score and echocardiographic parameters in patients with pulmonary embolism." In Annual Congress 2015. European Respiratory Society, 2015. http://dx.doi.org/10.1183/13993003.congress-2015.pa2483.

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Bastidas, A. R., I. Faizal Gómez, S. Ortiz Ramírez, G. Aguirre, and B. M. Mantilla Cardozo. "Validity Wells, Geneva and Pisa Score with Use of Intelligence Artificial for Pulmonary Embolism Diagnosis." In American Thoracic Society 2019 International Conference, May 17-22, 2019 - Dallas, TX. American Thoracic Society, 2019. http://dx.doi.org/10.1164/ajrccm-conference.2019.199.1_meetingabstracts.a6221.

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Hemnes, AR, AL Newman, B. Rosenbaum, TW Barrett, C. Zhou, TW Rice, and JH Newman. "The Combination of Normal Bedside End Tidal CO2 and Low Wells Score Accurately Excludes Pulmonary Embolism." In American Thoracic Society 2009 International Conference, May 15-20, 2009 • San Diego, California. American Thoracic Society, 2009. http://dx.doi.org/10.1164/ajrccm-conference.2009.179.1_meetingabstracts.a3292.

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Chatziantoniou, Argyro, Peiman Nazerian, Simone Vanni, Chiara Gigli, Giuseppe Francesco Sferrazza Papa, Emanuela Gambetta, Mattia Tullio, Stefano Centanni, and Giovanni Volpicelli. "A combination of the Wells score with multiorgan ultrasound to stratify patients with suspected pulmonary embolism." In Annual Congress 2015. European Respiratory Society, 2015. http://dx.doi.org/10.1183/13993003.congress-2015.oa493.

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Chatziantoniou, Argyro, Peiman Nazerian, Simone Vanni, Chiara Gigli, Giuseppe Francesco Sferrazza Papa, Emanuela Gambetta, Mattia Tullio, Stefano Centanni, and Giovanni Volpicelli. "LSC Abstract – A combination of the Wells score with multiorgan ultrasound to stratify patients with suspected pulmonary embolism." In ERS International Congress 2016 abstracts. European Respiratory Society, 2016. http://dx.doi.org/10.1183/13993003.congress-2016.pp124.

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Mahendra, M. "Characterization of Depositional Facies Using Artificial Intelligence Method Based on Electrical Log Data." In Digital Technical Conference. Indonesian Petroleum Association, 2020. http://dx.doi.org/10.29118/ipa20-sg-133.

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This study will focus on identifying depositional facies in uncored intervals using a gradient boosting classifier, based on electric logs: gamma-ray (GR), resistivity (ILD), neutron porosity (NPHI), and density (RHOB), as well as facies description and classification derived from cored intervals. Supervised learning with gradient boosting classifiers is the primary method that combines a lot of weak learning models to create a robust predictive model. A gradient boosting classifier was applied because the output will be in the form of images. We used nine wells such as four training data, and five testing data along with gamma-ray, resistivity, NPHI, and RHOB as input. The statistical methods were used to distribute facies on each well, and we used the F1 score and average of confusion matrix to validate the values. The result shows 0.718 or 71.8% of the F1 score and 0.6617 or 66.17% of the confusion matrix. With this level of accuracy, we conclude that the gradient boosting classifier methods are reliable enough to determine facies in the area that have limited core data with satisfying efficient results without reducing the accuracy.

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Asedegbega, Jerome, Oladayo Ayinde, and Alexander Nwakanma. "Application of Machine Learniing For Reservoir Facies Classification in Port Field, Offshore Niger Delta." In SPE Nigeria Annual International Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/207163-ms.

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Abstract Several computer-aided techniques have been developed in recent past to improve interpretational accuracy of subsurface geology. This paradigm shift has provided tremendous success in variety of Machine Learning Application domains and help for better feasibility study in reservoir evaluation using multiple classification techniques. Facies classification is an essential subsurface exploration task as sedimentary facies reflect associated physical, chemical, and biological conditions that formation unit experienced during sedimentation activity. This study however, employed formation samples for facies classification using Machine Learning (ML) techniques and classified different facies from well logs in seven (7) wells of the PORT Field, Offshore Niger Delta. Six wells were concatenated during data preparation and trained using supervised ML algorithms before validating the models by blind testing on one well log to predict discrete facies groups. The analysis started with data preparation and examination where various features of the available well data were conditioned. For the model building and performance, support vector machine, random forest, decision tree, extra tree, neural network (multilayer preceptor), k-nearest neighbor and logistic regression model were built after dividing the data sets into training, test, and blind test well data. Results of metric score for the blind test well estimated for the various models using Jaccard index and F1-score indicated 0.73 and 0.82 for support vector machine, 0.38 and 0.54 for random forest, 0.78 and 0.83 for extra tree, 0.91 and 0.95 for k-nearest neighbor, 0.41 and 0.56 for decision tree, 0.63 and 0.74 for logistic regression, 0.55 and 0.68 for neural network, respectively. The efficiency of ML techniques for enhancing the prediction accuracy and decreasing the procedure time and their approach toward the data, makes it importantly desirable to recommend them in subsurface facies classification analysis.

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Kara, Mustafa Can, Malina Majeran, Bret Peterson, Tom Wimberly, and Greg Sinclair. "A Machine Learning Workflow to Predict Anomalous Sanding Events in Deepwater Wells." In Offshore Technology Conference. OTC, 2021. http://dx.doi.org/10.4043/31234-ms.

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Abstract Deepwater wells possess a high risk of sand escaping the reservoir into the production systems. Sand production is a common operational issue which results in potential equipment damage and hence product contamination. Excessive sand erosion causes blockage in tubulars and cavities in downhole equipment (subsea valves, chokes, bends etc.), resulting in maintenance costs for subsea equipment that adds up to millions of dollars yearly to operators. In this work, a scalable Machine Learning (ML) model readily accessing historical and real-time feed of sensor and simulation data is built to develop a predictive solution. Deployed workflow can inform Control Room Operators before significant damage occurs. An anomaly detection architecture, a common unsupervised learning framework for maintenance analytics, is deployed. Anomaly detection models include methods within the scope of dimensionality reduction. Principle Component Analysis (PCA) and Long Short-Term Memory (LSTM) Autoencoders are deployed to tackle the problem through reconstruction of the original input. During the workflow, a threshold is calculated after batch training and passed along with anomaly error scores in real-time. An alarm is triggered once the real-time anomaly score passes the threshold calculated during batch training. ML outputs are streamlined in near real-time to the database. In this study, deployed ML model performance is benchmarked against a GOM Deepwater well where sanding is known to occur often. The ML Model architecture can process data that is captured by OSI PI historian, predict anomalous sanding events in advance, and is shown to be scalable to other wells in GOM. It is noted from this study that streamlined ML architecture and outputs simplify exploratory data analysis and model deployment across Onshore and Offshore Business Units. In addition, sanding stakeholders are notified in advance and can take early mitigative action before significant damage to wellhead or downhole equipment occurs instead of reacting to a possible sanding event offshore. The novelty of the utilized ML algorithm and process is in the ability to predict sanding anomalies in advance through ML batch training, infer prediction values near real-time, and scale to other assets.

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