Based on hydromachanics and the law of conservation of energy by means of the Bernoulli Equation, the matching relation of a pump pressure and delivery, losing energy of the magma when it flows along the pipes are res...Based on hydromachanics and the law of conservation of energy by means of the Bernoulli Equation, the matching relation of a pump pressure and delivery, losing energy of the magma when it flows along the pipes are researched. This thesis provide the theoretical basis for equipment selection and selection of pipeline.展开更多
At present in the process of water injection station operation, starting and stopping the pump caused system pressure fluctuations, and the fluctuations caused many problems about downstream injection wells. In order ...At present in the process of water injection station operation, starting and stopping the pump caused system pressure fluctuations, and the fluctuations caused many problems about downstream injection wells. In order to eliminate the fluctuations and reduce problems, taking start pump, connect pump test under pressure in the water injection station installed the rotor frequency control system Changqing oil field developed. During the experiment, by progressively increasing the pressure pump to verify start pump with pressure feasibility test, the result shows when the pressure in the 0-25MPa pressure start and connect pump can be realized, and forecast the maximum pressure of the current start of the station with pressure pump. Start pump with pressure achieve the elimination of pressure fluctuations, provide the prerequisites about realizeing stable water injection pressure, and ultimately realize oil field water injection station to be automatic water injection laid a foundation.展开更多
The single cylinder and multi-cylinder pumping dynamics model of a swash plate piston pump were improved.Particular attention has been paid to the design influences of key parts of the valve plate such as relief groov...The single cylinder and multi-cylinder pumping dynamics model of a swash plate piston pump were improved.Particular attention has been paid to the design influences of key parts of the valve plate such as relief groove,pre-compression/ expansion and fluid inertia effect of the unsteady flow.Some important parameters,such as the discharge area,discharge coefficient,fluid bulk modulus,were especially analyzed using numerical methods or by experiment-based estimation.Consequently,the mathematical results of pressure pulsation and flow ripple agree well with experimental results from the test-rig of the flow ripple.Therefore,the cross angle and the pre-compression angle of the valve plate was optimized,based on the pumping dynamics model.Considering both the flow ripple and the cylinder pressure of the pump,the cross angle is set to be 2.2° to 2.7° with a pre-compression angle of 1.7° to 2.2°,so the pumping dynamics character can obtain the best result.展开更多
Multistage multi-cluster hydraulic fracturing has enabled the economic exploitation of shale reservoirs,but the interpretation of hydraulic fracture parameters is challenging.The pressure signals after pump shutdown a...Multistage multi-cluster hydraulic fracturing has enabled the economic exploitation of shale reservoirs,but the interpretation of hydraulic fracture parameters is challenging.The pressure signals after pump shutdown are influenced by hydraulic fractures,which can reflect the geometric features of hydraulic fracture.The shutdown pressure can be used to interpret the hydraulic fracture parameters in a real-time and cost-effective manner.In this paper,a mathematical model for shutdown pressure evolution is developed considering the effects of wellbore friction,perforation friction and fluid loss in fractures.An efficient numerical simulation method is established by using the method of characteristics.Based on this method,the impacts of fracture half-length,fracture height,opened cluster and perforation number,and filtration coefficient on the evolution of shutdown pressure are analyzed.The results indicate that a larger fracture half-length may hasten the decay of shutdown pressure,while a larger fracture height can slow down the decay of shutdown pressure.A smaller number of opened clusters and perforations can significantly increase the perforation friction and decrease the overall level of shutdown pressure.A larger filtration coefficient may accelerate the fluid filtration in the fracture and hasten the drop of the shutdown pressure.The simulation method of shutdown pressure,as well as the analysis results,has important implications for the interpretation of hydraulic fracture parameters.展开更多
To select reasonable excavating and crushing process parameters and nozzle structure parameters is one of the key factors to realize commercial excavation of marine natural gas hydrate(hereinafter“hydrate”for short)...To select reasonable excavating and crushing process parameters and nozzle structure parameters is one of the key factors to realize commercial excavation of marine natural gas hydrate(hereinafter“hydrate”for short)in solid fluidization exploitation.For analyzing the factors influencing jet crushing efficiency of hydrate in actual engineering,nozzle diameter,pump pressure and other parameters were simulated and analyzed in k-εturbulence model based on the laboratory experiments and the field production test data at Liwan 3 Station in the northern South China Sea with a gas production rate of 120 thousand m^(3)/d as the target of commercial hydrate exploitation.And the following research results were obtained.First,the relationship curves of nozzle diameter,pump pressure and displacement are determined when the critical jet speed for crushing hydrate is 24 m/s.Second,the crushing rate to satisfy the daily hydrate sediment excavation of commercial exploitation is 2.48 m^(3)/min and its corresponding jet crushing diameter is 800 mm.Third,when the nozzle diameter is fixed,other parts in the process will be damaged if jet displacement and pump pressure are increased directly.In conclusion,these selected design parameters for commercially excavating and crushing marine non-diagenetic hydrate by means of solid fluidization are conducive to the optimal design of crushing parameters of hydrate in solid fluidization exploitation.展开更多
Influences of water head variations on the performances of a prototype reversible pump turbine are experimentally studied in generating mode within a wide range of load conditions(from 25% to 96% of the rated power). ...Influences of water head variations on the performances of a prototype reversible pump turbine are experimentally studied in generating mode within a wide range of load conditions(from 25% to 96% of the rated power). The pressure fluctuations of the reversible pump turbine at three different water heads(with non-dimensional values being 0.48, 0.71 and 0.90) are measured and compared based on the pressure data recorded in the whole flow passage of the turbine. Furthermore, effects of monitoring points and load variations on the impeller-induced unstable behavior(e.g. blade passing frequency and its harmonics) are quantitatively discussed. Our findings reveal that water head variations play a significant role on the pressure fluctuations and their propagation mechanisms inside the reversible pump turbine.展开更多
文摘Based on hydromachanics and the law of conservation of energy by means of the Bernoulli Equation, the matching relation of a pump pressure and delivery, losing energy of the magma when it flows along the pipes are researched. This thesis provide the theoretical basis for equipment selection and selection of pipeline.
文摘At present in the process of water injection station operation, starting and stopping the pump caused system pressure fluctuations, and the fluctuations caused many problems about downstream injection wells. In order to eliminate the fluctuations and reduce problems, taking start pump, connect pump test under pressure in the water injection station installed the rotor frequency control system Changqing oil field developed. During the experiment, by progressively increasing the pressure pump to verify start pump with pressure feasibility test, the result shows when the pressure in the 0-25MPa pressure start and connect pump can be realized, and forecast the maximum pressure of the current start of the station with pressure pump. Start pump with pressure achieve the elimination of pressure fluctuations, provide the prerequisites about realizeing stable water injection pressure, and ultimately realize oil field water injection station to be automatic water injection laid a foundation.
基金Project supported by the National Key Technologies Supporting Program of China during the 11th Five-Year Plan Period (Nos. 2006BAF01B01, 2006BAF01B04, and 2007AA03Z211)the National Natural Science Foundation of China (No. 50877070)the Technological Research and Development Programs of the Min-istry of Chinese Railways (No. 2009J006-L)
文摘The single cylinder and multi-cylinder pumping dynamics model of a swash plate piston pump were improved.Particular attention has been paid to the design influences of key parts of the valve plate such as relief groove,pre-compression/ expansion and fluid inertia effect of the unsteady flow.Some important parameters,such as the discharge area,discharge coefficient,fluid bulk modulus,were especially analyzed using numerical methods or by experiment-based estimation.Consequently,the mathematical results of pressure pulsation and flow ripple agree well with experimental results from the test-rig of the flow ripple.Therefore,the cross angle and the pre-compression angle of the valve plate was optimized,based on the pumping dynamics model.Considering both the flow ripple and the cylinder pressure of the pump,the cross angle is set to be 2.2° to 2.7° with a pre-compression angle of 1.7° to 2.2°,so the pumping dynamics character can obtain the best result.
基金The work is supported by the Sub-Project of“Research on Key Technologies and Equipment of Reservoir Stimulation”of China National Petroleum Corporation Post–14th Five-Year Plan Forward-Looking Major Science and Technology Project“Research on New Technology of Monitoring and Diagnosis of Horizontal Well Hydraulic Fracture Network Distribution Pattern”(2021DJ4502).
文摘Multistage multi-cluster hydraulic fracturing has enabled the economic exploitation of shale reservoirs,but the interpretation of hydraulic fracture parameters is challenging.The pressure signals after pump shutdown are influenced by hydraulic fractures,which can reflect the geometric features of hydraulic fracture.The shutdown pressure can be used to interpret the hydraulic fracture parameters in a real-time and cost-effective manner.In this paper,a mathematical model for shutdown pressure evolution is developed considering the effects of wellbore friction,perforation friction and fluid loss in fractures.An efficient numerical simulation method is established by using the method of characteristics.Based on this method,the impacts of fracture half-length,fracture height,opened cluster and perforation number,and filtration coefficient on the evolution of shutdown pressure are analyzed.The results indicate that a larger fracture half-length may hasten the decay of shutdown pressure,while a larger fracture height can slow down the decay of shutdown pressure.A smaller number of opened clusters and perforations can significantly increase the perforation friction and decrease the overall level of shutdown pressure.A larger filtration coefficient may accelerate the fluid filtration in the fracture and hasten the drop of the shutdown pressure.The simulation method of shutdown pressure,as well as the analysis results,has important implications for the interpretation of hydraulic fracture parameters.
基金Supported by the National Key R&D Program of China“New test tech-nology for solid fluidization of marine hydrate”(No.2016YFC0304008)CAE Major Strategic Consulting Program“Study on development strategy for deep-water engineering technology and deep-water equipment in China e seabed shallow natural gas hydrate and mineral resources”(No.2017-XZ-10-02-02).
文摘To select reasonable excavating and crushing process parameters and nozzle structure parameters is one of the key factors to realize commercial excavation of marine natural gas hydrate(hereinafter“hydrate”for short)in solid fluidization exploitation.For analyzing the factors influencing jet crushing efficiency of hydrate in actual engineering,nozzle diameter,pump pressure and other parameters were simulated and analyzed in k-εturbulence model based on the laboratory experiments and the field production test data at Liwan 3 Station in the northern South China Sea with a gas production rate of 120 thousand m^(3)/d as the target of commercial hydrate exploitation.And the following research results were obtained.First,the relationship curves of nozzle diameter,pump pressure and displacement are determined when the critical jet speed for crushing hydrate is 24 m/s.Second,the crushing rate to satisfy the daily hydrate sediment excavation of commercial exploitation is 2.48 m^(3)/min and its corresponding jet crushing diameter is 800 mm.Third,when the nozzle diameter is fixed,other parts in the process will be damaged if jet displacement and pump pressure are increased directly.In conclusion,these selected design parameters for commercially excavating and crushing marine non-diagenetic hydrate by means of solid fluidization are conducive to the optimal design of crushing parameters of hydrate in solid fluidization exploitation.
基金supported by the National Natural Science Foundation of China(Grant No.51506051)the Fundamental Research Funds for the Central Universities(Grant No.JB2015RCY04)+2 种基金the Open Research Fund Program of Key Laboratory of Fluid and Power Machinery(Xihua University)Ministry of Education(Grant No.szjj-2017-100-1-001)the Open Research Fund Program of State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources(Grant No.LAPS16014)
文摘Influences of water head variations on the performances of a prototype reversible pump turbine are experimentally studied in generating mode within a wide range of load conditions(from 25% to 96% of the rated power). The pressure fluctuations of the reversible pump turbine at three different water heads(with non-dimensional values being 0.48, 0.71 and 0.90) are measured and compared based on the pressure data recorded in the whole flow passage of the turbine. Furthermore, effects of monitoring points and load variations on the impeller-induced unstable behavior(e.g. blade passing frequency and its harmonics) are quantitatively discussed. Our findings reveal that water head variations play a significant role on the pressure fluctuations and their propagation mechanisms inside the reversible pump turbine.
