In order to promote the intelligent transformation and upgrading of the steel industry, intelligent technology features based on the current situation and challenges of the steel industry are discussed in this paper. ...In order to promote the intelligent transformation and upgrading of the steel industry, intelligent technology features based on the current situation and challenges of the steel industry are discussed in this paper. Based on both domestic and global research, functional analysis, reasonable positioning, and process optimization of each aspect of steel making are expounded. The current state of molten steel quality and implementation under narrow window control is analyzed. A method for maintaining stability in the narrow window control technology of steel quality is proposed, controlled by factors including composition, temperature, time, cleanliness, and consumption(raw material). Important guidance is provided for the future development of a green and intelligent steel manufacturing process.展开更多
In the Sichuan Basin,the drilling of complex deep and ultradeep wells is restricted by the casing sequence.Multiple pressure systems are usually encountered in the same open hole section,and narrow safety density wind...In the Sichuan Basin,the drilling of complex deep and ultradeep wells is restricted by the casing sequence.Multiple pressure systems are usually encountered in the same open hole section,and narrow safety density window is observed in vertical strata.The application of managed pressure drilling(MPD)technique which is often used in well drilling ensures the safe and efficient drilling,but it also brings about great challenges to the small-gap liner cementing at the lower part.Therefore,it is of great practical significance to research a cementing technology that can not only satisfy the quality requirement of small gap liner cementing,but also ensure the safe cementing in the strata with narrow safety density window.In this paper,a cementing technology based on precise managed pressure balancing method was proposed by referring to the successful application of MPD technique.According to the cementing design,the hydrostatic column pressure of annulusfluid is under-balanced(slightly lower than the formation pore pressure),and then a precise managed pressure drilling device is adopted to produce back pressure through wellhead restriction or apply wellhead compensation pressure,so that the balanced pore pressure can be reached in the process of cementing via the wellhead pressure and theflow friction offluid in the annulus.After the cementing is completed,a certain compensation pressure is applied to the annulus continuously to prevent annulus channeling during waiting on cement caused by insufficient static pressure and slurry weight loss.After this technology was applied to an ultradeep exploration well in the Sichuan Basin,the qualification rate of borehole cementing quality reached 97%,and the well sections with good cementing quality accounted for 76%.In conclusion,this technology needs no additional equipment,and only by virtue of the MPD equipment,it can achieve safe cementing construction and cementing quality improvement under high displacement efficiency.展开更多
With the growing demand for offshore energy,deepwater drilling has become a vital technology in petroleum engineering.However,conventional drilling systems often face limitations such as delayed bottomhole pressure re...With the growing demand for offshore energy,deepwater drilling has become a vital technology in petroleum engineering.However,conventional drilling systems often face limitations such as delayed bottomhole pressure response and low control precision,particularly under narrow pressure window and complex formation conditions.To address these challenges,Dual-layer Pipe dual-gradient drilling(DGD)technology has been introduced,utilizing a dual-pipe structure and downhole lift pumps to extend the pressure control range.Despite these advantages,current DGD systems lack fast and precise bottomhole pressure control due to their reliance on indirect flow-based methods.This study proposes a bottomhole pressure control method based on backpressure regulation using a hybrid fuzzy-PID control strategy.A dynamic pressure calculation model is developed for the Dual-layer Pipe DGD system,incorporating coupling among choke valve opening,surface backpressure,and bottomhole pressure.The fuzzy-PID controller adjusts valve operation in real-time based on pressure deviation and its rate of change,improving response speed and control accuracy.Simulink-based simulations demonstrate that the proposed system achieves rapid pressure regulation with an overshoot below 5%and steady-state error under 0.12%.Compared to conventional PID control,the fuzzy-PID system shows superior adaptability to pressure variations.This research enhances the theoretical foundation of backpressure control in deepwater DGD operations and provides a practical approach for improving safety and efficiency in complex drilling environments.展开更多
基金financially supported by the National Key R&D Program of China (No.2017YFB0304000)the National Natural Science Foundation of China (Nos.52074093, 51874102, 51704080, and 51674092)。
文摘In order to promote the intelligent transformation and upgrading of the steel industry, intelligent technology features based on the current situation and challenges of the steel industry are discussed in this paper. Based on both domestic and global research, functional analysis, reasonable positioning, and process optimization of each aspect of steel making are expounded. The current state of molten steel quality and implementation under narrow window control is analyzed. A method for maintaining stability in the narrow window control technology of steel quality is proposed, controlled by factors including composition, temperature, time, cleanliness, and consumption(raw material). Important guidance is provided for the future development of a green and intelligent steel manufacturing process.
基金supported by the National Major Science and Technology Project"Development demonstration project of large-scale carbonae gas fields in the Sichuan Basin-Research and application of large-scale deep carbonate gas reservoir drilling and production technology"(No:2016ZX05052-003)Pet roChina Major Science and Technology Project"Research and application of key technologies for maintaining 30billion cubic meters of natural gas production in Southwest Oil and Gas Field-Research and application ofdrilling,completion,and oil testing technologies for high temperature and high pressure sulfur-bearing deep wells in the Sichuan Basin"(No:2016E-0608)。
文摘In the Sichuan Basin,the drilling of complex deep and ultradeep wells is restricted by the casing sequence.Multiple pressure systems are usually encountered in the same open hole section,and narrow safety density window is observed in vertical strata.The application of managed pressure drilling(MPD)technique which is often used in well drilling ensures the safe and efficient drilling,but it also brings about great challenges to the small-gap liner cementing at the lower part.Therefore,it is of great practical significance to research a cementing technology that can not only satisfy the quality requirement of small gap liner cementing,but also ensure the safe cementing in the strata with narrow safety density window.In this paper,a cementing technology based on precise managed pressure balancing method was proposed by referring to the successful application of MPD technique.According to the cementing design,the hydrostatic column pressure of annulusfluid is under-balanced(slightly lower than the formation pore pressure),and then a precise managed pressure drilling device is adopted to produce back pressure through wellhead restriction or apply wellhead compensation pressure,so that the balanced pore pressure can be reached in the process of cementing via the wellhead pressure and theflow friction offluid in the annulus.After the cementing is completed,a certain compensation pressure is applied to the annulus continuously to prevent annulus channeling during waiting on cement caused by insufficient static pressure and slurry weight loss.After this technology was applied to an ultradeep exploration well in the Sichuan Basin,the qualification rate of borehole cementing quality reached 97%,and the well sections with good cementing quality accounted for 76%.In conclusion,this technology needs no additional equipment,and only by virtue of the MPD equipment,it can achieve safe cementing construction and cementing quality improvement under high displacement efficiency.
基金the Sichuan Provincial Key R&D Program(Regional Innovation Coop-eration Project 2025YFHZ0306)Open Fund(PLN 2022-46)of State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation(Southwest Petroleum University)Special Support for Sichuan Postdoctoral Research Projects.
文摘With the growing demand for offshore energy,deepwater drilling has become a vital technology in petroleum engineering.However,conventional drilling systems often face limitations such as delayed bottomhole pressure response and low control precision,particularly under narrow pressure window and complex formation conditions.To address these challenges,Dual-layer Pipe dual-gradient drilling(DGD)technology has been introduced,utilizing a dual-pipe structure and downhole lift pumps to extend the pressure control range.Despite these advantages,current DGD systems lack fast and precise bottomhole pressure control due to their reliance on indirect flow-based methods.This study proposes a bottomhole pressure control method based on backpressure regulation using a hybrid fuzzy-PID control strategy.A dynamic pressure calculation model is developed for the Dual-layer Pipe DGD system,incorporating coupling among choke valve opening,surface backpressure,and bottomhole pressure.The fuzzy-PID controller adjusts valve operation in real-time based on pressure deviation and its rate of change,improving response speed and control accuracy.Simulink-based simulations demonstrate that the proposed system achieves rapid pressure regulation with an overshoot below 5%and steady-state error under 0.12%.Compared to conventional PID control,the fuzzy-PID system shows superior adaptability to pressure variations.This research enhances the theoretical foundation of backpressure control in deepwater DGD operations and provides a practical approach for improving safety and efficiency in complex drilling environments.
