A jet mill bit(JMB)is proposed to increase the drilling efficiency and safety of horizontal wells,which has the hydraulic characteristics of depressurization and cuttings cleaning.This paper fills the gap in the hydra...A jet mill bit(JMB)is proposed to increase the drilling efficiency and safety of horizontal wells,which has the hydraulic characteristics of depressurization and cuttings cleaning.This paper fills the gap in the hydraulic study of the JMB by focusing on the hydraulic modeling and optimization of the JMB and considering these two hydraulic characteristics.First,the hydraulic depressurization model and the hydraulic cuttings cleaning model of the JMB are developed respectively.In the models,the pressure ratio and efficiency are chosen as the evaluation parameters of the depressurization capacity of the JMB,and the jet hydraulic power and jet impact force are chosen as the evaluation parameters of cuttings cleaning capacity of the JMB.Second,based on the hydraulic models,the effects of model parameters[friction loss coefficient,target inclination angle,rate of penetration(ROP),flow ratio,and well depth]on the hydraulic performance of the JMB are investigated.The results show that an increase in the friction loss coefficient and target inclination angle cause a significant reduction in the hydraulic depressurization capacity,and the effect of ROP is negligible.The flow ratio is positively related to the hydraulic cuttings cleaning capacity,and the well depth determines the maximum hydraulic cuttings cleaning capacity.Finally,by combining the hydraulic depressurization model and hydraulic cuttings cleaning model,an optimization method of JMB hydraulics is proposed to simultaneously maximize the jet depressurization capacity and the cuttings cleaning capacity.According to the drilling parameters given,the optimal values of the drilling fluid flow rate,backward nozzle diameter,forward nozzle diameter,and throat diameter can be determined.Moreover,a case study is conducted to verify the effectiveness of the optimization method.展开更多
Analytical and numerical computed models are developed for reverse pulse cleaning system of candle ceramic filters. A standard turbulent model is demonstrated suitably to the designing computation of reverse pulse cle...Analytical and numerical computed models are developed for reverse pulse cleaning system of candle ceramic filters. A standard turbulent model is demonstrated suitably to the designing computation of reverse pulse cleaning system from the experimental and one dimensional computational result. The computed results can be used to guide the designing of reverse pulse cleaning system, which is optimum Venturi geometry. From the computed results, the general conclusions and the designing methods are obtained.展开更多
随着深度学习和神经网络技术的不断发展,光学字符识别(Optical Character Recognition,OCR)技术在从各类图像中准确识别文本信息方面取得了显著进展,无论是印刷体文档、手写笔记,还是包含文字的图片,OCR技术都能较为准确地提取其中的文...随着深度学习和神经网络技术的不断发展,光学字符识别(Optical Character Recognition,OCR)技术在从各类图像中准确识别文本信息方面取得了显著进展,无论是印刷体文档、手写笔记,还是包含文字的图片,OCR技术都能较为准确地提取其中的文字内容,为信息处理和数字化提供了极大的便利。然而在实际应用场景中,OCR技术面临着诸多挑战。不同的光照条件、字体样式、背景干扰等,都会影响识别的准确性。同时,还存在着诸多单点问题,比如特定领域的专业术语识别困难、不规则排版文字的处理不佳等。如何快速响应用户的个性化定制需求,并实现模型的高效微调与快速迭代,已成为影响用户体验的关键因素之一。针对OCR技术在移动端模型大规模数据微调中的实际需求,该文重点探讨了数据清洗与模型微调技术在快速微调实践中的应用与效果。通过有效的数据清洗,可以去除噪声数据,提高数据质量,为模型微调提供更好的基础。而模型微调技术则能够让模型更快地适应新的需求,实现快速迭代,从而提升OCR技术在实际应用中的性能和用户体验。展开更多
The compound dry cleaning principle is briefly described.A beneficiation test on South African coal was conducted using a model compound dry cleaning apparatus.Excellent results were obtained and the optimum operating...The compound dry cleaning principle is briefly described.A beneficiation test on South African coal was conducted using a model compound dry cleaning apparatus.Excellent results were obtained and the optimum operating parameters were determined.They are：an amplitude of 3.0 mm,a motor frequency of 47.5 Hz,an air volume of 50%,a transverse angle of 7°,and a longitudinal angle of-2°.These conditions yield a clean coal containing 11%ash and a coal production of 75%.The organic efficiency,η,is 95.86%.These results show that the South African coal can be separated effectively by compound dry cleaning,which will popularize the compound dry cleaning method.展开更多
Horizontal fracture-simulated completions remain the most reliable method of producing hydrocarbons from shale formations. The vast majority of unconventional wells are completed using the “Plug and Perf” method. Th...Horizontal fracture-simulated completions remain the most reliable method of producing hydrocarbons from shale formations. The vast majority of unconventional wells are completed using the “Plug and Perf” method. This method involves using either a coiled tubing (CT) with a positive displacement motor or a jointed pipe to mill out composite plugs after fracturing operations are completed. An estimated average of 120,000 composite plugs is installed in the US alone each year. Bridge plug drillouts from milling operations tend to accumulate in horizontal wells and can cause stuck pipe incidents and loss of well control. Efficient removal of composite plugs’ debris is crucial in achieving operational efficacies and full production potential. This paper provides an overview of the various bridge plug drillouts cleaning practices adopted in horizontal wells. It discusses several case histories, showcasing how operators solved cleanout challenges. Developed mechanistic models to better understand hole cleaning are also reviewed. As more unconventional wells are being set at more extensive depths, an economical and optimized coiled tubing process becomes increasingly important. This paper focuses on delivering a more conclusive set of recommendations to increase efficiency and improve current composite plug coiled tubing cleaning-milling practices, increase operational efficiency and reduce cost.展开更多
基金financially supported by Youth Project of Natural Science Basic Research Program of Shaanxi Province(Grant number:2023-JC-QN-0538)Scientifical Research Program for Youth Innovation Team Construction of Shaanxi Provincial Department of Education(Grant number:21JP054,22JP032)+1 种基金National Natural Science Foundation of China(Grant numbers:52174012,51804322,51821092,51774301,U1762214)Open Fund(PLC 20210404)of State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation(Chengdu University of Technology)。
文摘A jet mill bit(JMB)is proposed to increase the drilling efficiency and safety of horizontal wells,which has the hydraulic characteristics of depressurization and cuttings cleaning.This paper fills the gap in the hydraulic study of the JMB by focusing on the hydraulic modeling and optimization of the JMB and considering these two hydraulic characteristics.First,the hydraulic depressurization model and the hydraulic cuttings cleaning model of the JMB are developed respectively.In the models,the pressure ratio and efficiency are chosen as the evaluation parameters of the depressurization capacity of the JMB,and the jet hydraulic power and jet impact force are chosen as the evaluation parameters of cuttings cleaning capacity of the JMB.Second,based on the hydraulic models,the effects of model parameters[friction loss coefficient,target inclination angle,rate of penetration(ROP),flow ratio,and well depth]on the hydraulic performance of the JMB are investigated.The results show that an increase in the friction loss coefficient and target inclination angle cause a significant reduction in the hydraulic depressurization capacity,and the effect of ROP is negligible.The flow ratio is positively related to the hydraulic cuttings cleaning capacity,and the well depth determines the maximum hydraulic cuttings cleaning capacity.Finally,by combining the hydraulic depressurization model and hydraulic cuttings cleaning model,an optimization method of JMB hydraulics is proposed to simultaneously maximize the jet depressurization capacity and the cuttings cleaning capacity.According to the drilling parameters given,the optimal values of the drilling fluid flow rate,backward nozzle diameter,forward nozzle diameter,and throat diameter can be determined.Moreover,a case study is conducted to verify the effectiveness of the optimization method.
基金TheNationalNaturalScienceFoundationofChina (No .5 9776 0 2 5 )andtheHi TechResearchandDevelopmentProgramofChina (S 86 3No.2 0 0 1AA3330 40 ) )
文摘Analytical and numerical computed models are developed for reverse pulse cleaning system of candle ceramic filters. A standard turbulent model is demonstrated suitably to the designing computation of reverse pulse cleaning system from the experimental and one dimensional computational result. The computed results can be used to guide the designing of reverse pulse cleaning system, which is optimum Venturi geometry. From the computed results, the general conclusions and the designing methods are obtained.
文摘随着深度学习和神经网络技术的不断发展,光学字符识别(Optical Character Recognition,OCR)技术在从各类图像中准确识别文本信息方面取得了显著进展,无论是印刷体文档、手写笔记,还是包含文字的图片,OCR技术都能较为准确地提取其中的文字内容,为信息处理和数字化提供了极大的便利。然而在实际应用场景中,OCR技术面临着诸多挑战。不同的光照条件、字体样式、背景干扰等,都会影响识别的准确性。同时,还存在着诸多单点问题,比如特定领域的专业术语识别困难、不规则排版文字的处理不佳等。如何快速响应用户的个性化定制需求,并实现模型的高效微调与快速迭代,已成为影响用户体验的关键因素之一。针对OCR技术在移动端模型大规模数据微调中的实际需求,该文重点探讨了数据清洗与模型微调技术在快速微调实践中的应用与效果。通过有效的数据清洗,可以去除噪声数据,提高数据质量,为模型微调提供更好的基础。而模型微调技术则能够让模型更快地适应新的需求,实现快速迭代,从而提升OCR技术在实际应用中的性能和用户体验。
基金financially supported by the National Natural Science Foundation of China(Nos.90510002 and 50921002)the Fundamental Research Funds for the Central Universities (China University of Mining and Technology)(No.2010ZDP01A06).
文摘The compound dry cleaning principle is briefly described.A beneficiation test on South African coal was conducted using a model compound dry cleaning apparatus.Excellent results were obtained and the optimum operating parameters were determined.They are：an amplitude of 3.0 mm,a motor frequency of 47.5 Hz,an air volume of 50%,a transverse angle of 7°,and a longitudinal angle of-2°.These conditions yield a clean coal containing 11%ash and a coal production of 75%.The organic efficiency,η,is 95.86%.These results show that the South African coal can be separated effectively by compound dry cleaning,which will popularize the compound dry cleaning method.
文摘Horizontal fracture-simulated completions remain the most reliable method of producing hydrocarbons from shale formations. The vast majority of unconventional wells are completed using the “Plug and Perf” method. This method involves using either a coiled tubing (CT) with a positive displacement motor or a jointed pipe to mill out composite plugs after fracturing operations are completed. An estimated average of 120,000 composite plugs is installed in the US alone each year. Bridge plug drillouts from milling operations tend to accumulate in horizontal wells and can cause stuck pipe incidents and loss of well control. Efficient removal of composite plugs’ debris is crucial in achieving operational efficacies and full production potential. This paper provides an overview of the various bridge plug drillouts cleaning practices adopted in horizontal wells. It discusses several case histories, showcasing how operators solved cleanout challenges. Developed mechanistic models to better understand hole cleaning are also reviewed. As more unconventional wells are being set at more extensive depths, an economical and optimized coiled tubing process becomes increasingly important. This paper focuses on delivering a more conclusive set of recommendations to increase efficiency and improve current composite plug coiled tubing cleaning-milling practices, increase operational efficiency and reduce cost.
