To address the challenges associated with existing separated zone oil production technologies,such as incompatibility with pump inspection operations,short effective working life,and poor communication reliability,an ...To address the challenges associated with existing separated zone oil production technologies,such as incompatibility with pump inspection operations,short effective working life,and poor communication reliability,an innovative electromagnetic coupling intelligent zonal oil production technology has been proposed.The core and accessory tools have been developed and applied in field tests.This technology employs a pipe string structure incorporation a release sub,which separates the production and allocation pipe strings.When the two strings are docked downhole,electromagnetic coupling enables close-range wireless transmission of electrical power and signals between the strings,powering multiple downhole intelligent production allocators(IPAs)and enabling two-way communication.Core tools adapted to the complex working conditions downhole were developed,including downhole electricity&signal transmission equipment based on electromagnetic coupling(EST),IPAs,and ground communication controllers(GCCs).Accessory tools,including large-diameter release sub anchor and cable-crossing packers,have also been technically finalized.Field tests conducted on ten wells in Daqing Oilfield demonstrated that the downhole docking of the two strings was convenient and reliable,and the EST worked stably.Real-time monitoring of flow rate,pressure and temperature in separate layers and regulation of zonal fluid production were also achieved.This technology has enhanced reservoir understanding and achieved practical production results of increased oil output with reduced water cut.展开更多
In this paper .the change of the crystalline phases in hardened magnesium oxychloride cement (MOC) paste in mater was analyzed by XRD. It was developed that the reaction products 5 phase or 3 phase of MOC are instable...In this paper .the change of the crystalline phases in hardened magnesium oxychloride cement (MOC) paste in mater was analyzed by XRD. It was developed that the reaction products 5 phase or 3 phase of MOC are instable in water and can be changed into Mg(OH)2 by the action of water, which causes the content of 5 phase or 3 phase to be less and less,the content of Mg(OH)2 to be more and more and the strength to be the lower the lower,after hardended MOC paste was immersed in water. The change of 5 pliase and 3 phase into Mg(OH)2 is not a dissolve process, but a hydrolysis process. The hydrolysis products of 5 phase and 3 phase are Mg(OH)2 precipitation and soluble Cl-,AIg+ ions and H2O. The hydrolysis is sponta-neous thermodynamically and its chemical kinatic equation is C = C,,e-k Thus .it is suggested that only by enhancing the stability of 5 phase or 3 phase in water and preventing 5 phase or 3 phase from the hydrolyzing can the water resistance of MOC be improved well.展开更多
In this paper, by in-depth geological research of Kalamkas Oilfield in Central Asia, the geological body has been re-ascertained; combined with fine study of reservoir engineering, based on the understanding of the di...In this paper, by in-depth geological research of Kalamkas Oilfield in Central Asia, the geological body has been re-ascertained; combined with fine study of reservoir engineering, based on the understanding of the distribution of remaining oil horizontal wells have been given full play to stabilizing oil production and controlling water cut, reducing the producing pressure drop, improving well productivity and other advantages, and the development and deployment has been optimized; horizontal wells have been applied to solve problems such as old well casing damages, shutting down wells, low-productivity and low- efficiency wells, and high water cut wells to improve the utilization rate of old wells; through separate layer system improved injection production pattern, adjustment wells have been optimized and deployed, and part measures wells have been preferably selected to tap the residual oil improve the degree of reserves control realize the stabilization of oil production and control of water cut in an old oilfield, and further improve the development effects.展开更多
With the grade of hydrocarbon resources becoming poorer,tight sandstone gas reservoirs may serve as the key to the enhancement of both reserves and productivity.Accordingly,high efficient and sustainable development o...With the grade of hydrocarbon resources becoming poorer,tight sandstone gas reservoirs may serve as the key to the enhancement of both reserves and productivity.Accordingly,high efficient and sustainable development of the large and over-large tight sandstone reservoirs is very important.However,currently,there is no effective method available for macro-analysis.Based on the latest research findings from the Sulige Gasfield,the largest onshore tight sandstone gas reservoir in China,studies were conducted in five aspects,i.e.reserve scale,development scale,dynamic reserve evaluation,rules in production declines of gasfields and undeveloped resource evaluation,to identify challenges to the production stabilization of gas reservoirs.In addition,key evidences and constraints for the solutions to the difficulties in production stabilization were proposed to provide necessary technical supports for high-efficient development in later stages.Research results show that the major challenges to production stabilization include seven aspects,such as low development induced by improper allocation of well patterns,uneven declines in productivity induced by specific features of reservoir formations and fluids,difficulties in the development of some reserves due to complex gas/water correlation,and differences in production performances by using different production techniques.Finally,guided by the development principles of“promoting productivity by using innovative technologies in different spaces and time”,13 key technologies,such as comprehensive optimization of development well patterns,multi-dimensional matrix for gas well management and“positive”water discharging and gas production technologies,were proposed to further prolong peak production time and enhance the recovery rates of tight gas reservoirs.展开更多
Cultivated land plays a pivotal role in ensuring national food security,particularly in populous nations like China,where substantial investments are made to develop cultivated land as a counterbalance to construction...Cultivated land plays a pivotal role in ensuring national food security,particularly in populous nations like China,where substantial investments are made to develop cultivated land as a counterbalance to construction-occupied areas.Consequently,long-term,effective monitoring of the utilization of newly cultivated land becomes imperative.This study introduces a comprehensive monitoring framework,designed for refined scales,that leverages remote sensing data.The framework focuses on the sustainable utilization of newly cultivated land,emphasizing utilization sustainability,productivity stability,and landscape integration.Its effectiveness was validated through a case study in Guangdong province,China.The results revealed satisfactory utilization sustainability and improved productivity stability of newly cultivated land in Guangdong,though landscape integration showed sub-optimal results.Furthermore,the comprehensive evaluation categorized the newly cultivated land into three levels and eight types.The study recommends enhancing the site selection process for newly cultivated land and improving the long-term monitoring,as well as incentive and constraint mechanisms,for their utilization.This study can provide a scientific reference to bolster the implementation of cultivated land protection policies,thereby contributing significantly to high-quality economic and social development.展开更多
Some approaches or parameters were employed to indicate the stage of stable pitting such as the energy distribution obtained by the wavelet analysis or the Hilbert spectra, the recurrence quantitative parameters obtai...Some approaches or parameters were employed to indicate the stage of stable pitting such as the energy distribution obtained by the wavelet analysis or the Hilbert spectra, the recurrence quantitative parameters obtained from the recurrence analysis, and the noise resistance as well in the electrochemical noise analysis. The pitting current density may be a key parameter for the stable pitting estimation which determined the dissolution-diffusion sustainable dynamic balance in the pit according to the theoretical framework proposed by Li, Scully, and Frankel.While the pit stable product defined the critical transportation condition under the high pitting current density.The pitting current growth rate as well as its amplitude was adopted to indicate the stable pitting transition according to the electrochemical transient analysis during the stainless-steel pitting process, which may provide the quantitative indicator agreed with the theoretical framework.展开更多
Corrosion is a damage or a change of state of materials caused by interactions between materials and environmental factors, which, together with fracture and wear, have become the three major reasons for the failure o...Corrosion is a damage or a change of state of materials caused by interactions between materials and environmental factors, which, together with fracture and wear, have become the three major reasons for the failure of structural materials. Normally, corrosion takes place or originates on or from the surface of materials. Therefore, surface technology （such as coating） is one of the important measures to mitigate and control the process of corrosion.展开更多
A dynamic two-zone model is proposed to address the formation of granulation and drying zones in fluidized bed layering granulation processes with internal product classification. The model assumes a constant volume f...A dynamic two-zone model is proposed to address the formation of granulation and drying zones in fluidized bed layering granulation processes with internal product classification. The model assumes a constant volume for the granulation zone, but a variable overall volume for the fluidized bed to account for classified product removal. The model is used to study the effect of various process parameters on dynamics and process stability. Stability is shown to depend on the separation diameter of product removal and the flow rate of the injected liquid. A lower and upper range of separation diameters with stable process behavior are found. In an intermediate range instability in the form of self-sustained oscillations is observed. The lower stability boundary is in qualitative agreement with recent experimental observations （Schmidt, Bück, ＆ Tsotsas, 2015）; the upper boundary was reported in a theoretical paper by Vreman, Van Lare, and Hounslow （2009） based on a single zone model.展开更多
Water injection can compensate for pressure depletion of production.This paper firstly investigated into the equilibrium issue among water influx,water injection and production.Equilibrium principle was elaborated thr...Water injection can compensate for pressure depletion of production.This paper firstly investigated into the equilibrium issue among water influx,water injection and production.Equilibrium principle was elaborated through deduction of equilibrium equation and presentation of equilibrium curves with an“equilibrium point”.Influences of artificial controllable factors(e.g.well ratio of injection to production and total well number)on equilibrium were particularly analyzed using field data.It was found that the influences were mainly reflected as the location move of equilibrium point with factor change.Then reservoir pressure maintenance level was especially introduced to reveal the variation law of liquid rate and oil rate with the rising of water cut.It was also found that,even if reservoir pressure kept constant,oil rate still inevitably declined.However,in the field,a stabilized oil rate was always pursued for development efficiency.Therefore,the equilibrium issue of stabilized oil production was studied deeply through probing into some effective measures to realize oil rate stability after the increase of water cut for the example reservoir.Successful example application indicated that the integrated approach was very practical and feasible,and hence could be used to the other similar reservoir.展开更多
This study focuses on the integrated energy production system in industrial parks, addressing the problem of stable load dispatch of equipment under demand fluctuations. A cross-level method for steam load smoothing a...This study focuses on the integrated energy production system in industrial parks, addressing the problem of stable load dispatch of equipment under demand fluctuations. A cross-level method for steam load smoothing and optimization is proposed, aiming to achieve stable production and optimal economic performance through three levels of integration: load forecasting, load dispatch, and load regulation. Unlike traditional methods that directly use load forecasting values, heat network elasticity is presented as a buffer between demand and supply. Constraints for minimal changes in equipment load and operational parameters are established for smooth regulation. Industrial cases demonstrate that the load forecasting model has mean absolute percentage errors of 2.44% and 1.68% for medium-pressure and low-pressure steam, respectively, meeting accuracy requirements. The modified supply-side load smoothness is effectively improved by considering heat network elasticity. The method increases boiler efficiency by 1.92%, reducing average coal consumption by 0.92 t/h. Compared to manual operation, the proposed model leads to an average increase of 5.69 MW in power generation and an average reduction of 10.81% in coal-to-electricity ratio. This study verifies the importance of smooth integration across different levels and analyzes the effective response of the proposed method to the uncertainty in load forecasting. The method demonstrates the enormous potential of data-driven methods in achieving safe, economical, and sustainable production in industrial parks.展开更多
基金Supported by the National Natural Science Foundation of China(52374067)PetroChina Scientific Research and Technology Development Project(2021ZG12)PetroChina Technology Project(2023ZZ09).
文摘To address the challenges associated with existing separated zone oil production technologies,such as incompatibility with pump inspection operations,short effective working life,and poor communication reliability,an innovative electromagnetic coupling intelligent zonal oil production technology has been proposed.The core and accessory tools have been developed and applied in field tests.This technology employs a pipe string structure incorporation a release sub,which separates the production and allocation pipe strings.When the two strings are docked downhole,electromagnetic coupling enables close-range wireless transmission of electrical power and signals between the strings,powering multiple downhole intelligent production allocators(IPAs)and enabling two-way communication.Core tools adapted to the complex working conditions downhole were developed,including downhole electricity&signal transmission equipment based on electromagnetic coupling(EST),IPAs,and ground communication controllers(GCCs).Accessory tools,including large-diameter release sub anchor and cable-crossing packers,have also been technically finalized.Field tests conducted on ten wells in Daqing Oilfield demonstrated that the downhole docking of the two strings was convenient and reliable,and the EST worked stably.Real-time monitoring of flow rate,pressure and temperature in separate layers and regulation of zonal fluid production were also achieved.This technology has enhanced reservoir understanding and achieved practical production results of increased oil output with reduced water cut.
文摘In this paper .the change of the crystalline phases in hardened magnesium oxychloride cement (MOC) paste in mater was analyzed by XRD. It was developed that the reaction products 5 phase or 3 phase of MOC are instable in water and can be changed into Mg(OH)2 by the action of water, which causes the content of 5 phase or 3 phase to be less and less,the content of Mg(OH)2 to be more and more and the strength to be the lower the lower,after hardended MOC paste was immersed in water. The change of 5 pliase and 3 phase into Mg(OH)2 is not a dissolve process, but a hydrolysis process. The hydrolysis products of 5 phase and 3 phase are Mg(OH)2 precipitation and soluble Cl-,AIg+ ions and H2O. The hydrolysis is sponta-neous thermodynamically and its chemical kinatic equation is C = C,,e-k Thus .it is suggested that only by enhancing the stability of 5 phase or 3 phase in water and preventing 5 phase or 3 phase from the hydrolyzing can the water resistance of MOC be improved well.
文摘In this paper, by in-depth geological research of Kalamkas Oilfield in Central Asia, the geological body has been re-ascertained; combined with fine study of reservoir engineering, based on the understanding of the distribution of remaining oil horizontal wells have been given full play to stabilizing oil production and controlling water cut, reducing the producing pressure drop, improving well productivity and other advantages, and the development and deployment has been optimized; horizontal wells have been applied to solve problems such as old well casing damages, shutting down wells, low-productivity and low- efficiency wells, and high water cut wells to improve the utilization rate of old wells; through separate layer system improved injection production pattern, adjustment wells have been optimized and deployed, and part measures wells have been preferably selected to tap the residual oil improve the degree of reserves control realize the stabilization of oil production and control of water cut in an old oilfield, and further improve the development effects.
基金National Science and Technology Major Project“Demonstration Project of Development of Large-Scale Low-Permeability Lithologic and Stratigraphic Reservoirs in the Ordos Basin”(No.2011ZX05044)Scientific Research and Technical Development Project of CNPC(No.2012E-1306).
文摘With the grade of hydrocarbon resources becoming poorer,tight sandstone gas reservoirs may serve as the key to the enhancement of both reserves and productivity.Accordingly,high efficient and sustainable development of the large and over-large tight sandstone reservoirs is very important.However,currently,there is no effective method available for macro-analysis.Based on the latest research findings from the Sulige Gasfield,the largest onshore tight sandstone gas reservoir in China,studies were conducted in five aspects,i.e.reserve scale,development scale,dynamic reserve evaluation,rules in production declines of gasfields and undeveloped resource evaluation,to identify challenges to the production stabilization of gas reservoirs.In addition,key evidences and constraints for the solutions to the difficulties in production stabilization were proposed to provide necessary technical supports for high-efficient development in later stages.Research results show that the major challenges to production stabilization include seven aspects,such as low development induced by improper allocation of well patterns,uneven declines in productivity induced by specific features of reservoir formations and fluids,difficulties in the development of some reserves due to complex gas/water correlation,and differences in production performances by using different production techniques.Finally,guided by the development principles of“promoting productivity by using innovative technologies in different spaces and time”,13 key technologies,such as comprehensive optimization of development well patterns,multi-dimensional matrix for gas well management and“positive”water discharging and gas production technologies,were proposed to further prolong peak production time and enhance the recovery rates of tight gas reservoirs.
基金National Natural Science Foundation of China,No.42271259。
文摘Cultivated land plays a pivotal role in ensuring national food security,particularly in populous nations like China,where substantial investments are made to develop cultivated land as a counterbalance to construction-occupied areas.Consequently,long-term,effective monitoring of the utilization of newly cultivated land becomes imperative.This study introduces a comprehensive monitoring framework,designed for refined scales,that leverages remote sensing data.The framework focuses on the sustainable utilization of newly cultivated land,emphasizing utilization sustainability,productivity stability,and landscape integration.Its effectiveness was validated through a case study in Guangdong province,China.The results revealed satisfactory utilization sustainability and improved productivity stability of newly cultivated land in Guangdong,though landscape integration showed sub-optimal results.Furthermore,the comprehensive evaluation categorized the newly cultivated land into three levels and eight types.The study recommends enhancing the site selection process for newly cultivated land and improving the long-term monitoring,as well as incentive and constraint mechanisms,for their utilization.This study can provide a scientific reference to bolster the implementation of cultivated land protection policies,thereby contributing significantly to high-quality economic and social development.
基金support of the Ningxia Nature Science Foundation (2023AAC03339)
文摘Some approaches or parameters were employed to indicate the stage of stable pitting such as the energy distribution obtained by the wavelet analysis or the Hilbert spectra, the recurrence quantitative parameters obtained from the recurrence analysis, and the noise resistance as well in the electrochemical noise analysis. The pitting current density may be a key parameter for the stable pitting estimation which determined the dissolution-diffusion sustainable dynamic balance in the pit according to the theoretical framework proposed by Li, Scully, and Frankel.While the pit stable product defined the critical transportation condition under the high pitting current density.The pitting current growth rate as well as its amplitude was adopted to indicate the stable pitting transition according to the electrochemical transient analysis during the stainless-steel pitting process, which may provide the quantitative indicator agreed with the theoretical framework.
文摘Corrosion is a damage or a change of state of materials caused by interactions between materials and environmental factors, which, together with fracture and wear, have become the three major reasons for the failure of structural materials. Normally, corrosion takes place or originates on or from the surface of materials. Therefore, surface technology （such as coating） is one of the important measures to mitigate and control the process of corrosion.
文摘A dynamic two-zone model is proposed to address the formation of granulation and drying zones in fluidized bed layering granulation processes with internal product classification. The model assumes a constant volume for the granulation zone, but a variable overall volume for the fluidized bed to account for classified product removal. The model is used to study the effect of various process parameters on dynamics and process stability. Stability is shown to depend on the separation diameter of product removal and the flow rate of the injected liquid. A lower and upper range of separation diameters with stable process behavior are found. In an intermediate range instability in the form of self-sustained oscillations is observed. The lower stability boundary is in qualitative agreement with recent experimental observations （Schmidt, Bück, ＆ Tsotsas, 2015）; the upper boundary was reported in a theoretical paper by Vreman, Van Lare, and Hounslow （2009） based on a single zone model.
基金the NSFC(National Natural Science Foundation of China)for supporting this article through two projects:the National Science Fund for Young Scholars of China(Grant No.51304164)“Research on the pressure dynamics of multiple-acidized-fractured horizontal wells in fractured-vuggy carbonate formations”+2 种基金the National Science Fund for Distinguished Young Scholars of China(Grant No.51525404),“Fracturing and acidizing in low permeability and tight reservoirs”financially supported by the Fok Ying Tung Education Foundation for Young Teachers in the Higher Education Institutions of China(Grant No.151050)financially supported by a basic research project under Grant No.2015JY0132 from the Science and Technology Department of Sichuan Province.
文摘Water injection can compensate for pressure depletion of production.This paper firstly investigated into the equilibrium issue among water influx,water injection and production.Equilibrium principle was elaborated through deduction of equilibrium equation and presentation of equilibrium curves with an“equilibrium point”.Influences of artificial controllable factors(e.g.well ratio of injection to production and total well number)on equilibrium were particularly analyzed using field data.It was found that the influences were mainly reflected as the location move of equilibrium point with factor change.Then reservoir pressure maintenance level was especially introduced to reveal the variation law of liquid rate and oil rate with the rising of water cut.It was also found that,even if reservoir pressure kept constant,oil rate still inevitably declined.However,in the field,a stabilized oil rate was always pursued for development efficiency.Therefore,the equilibrium issue of stabilized oil production was studied deeply through probing into some effective measures to realize oil rate stability after the increase of water cut for the example reservoir.Successful example application indicated that the integrated approach was very practical and feasible,and hence could be used to the other similar reservoir.
基金supported by National Key R&D Program of China(Grant No.2022YFB3304502)National Natural Science Foundation of China(Grant No.51806190)+1 种基金National Key R&D Program of China(Grant No.2023YFE0108600)Self-directed project,State Key Laboratory of Clean Energy Utilization.
文摘This study focuses on the integrated energy production system in industrial parks, addressing the problem of stable load dispatch of equipment under demand fluctuations. A cross-level method for steam load smoothing and optimization is proposed, aiming to achieve stable production and optimal economic performance through three levels of integration: load forecasting, load dispatch, and load regulation. Unlike traditional methods that directly use load forecasting values, heat network elasticity is presented as a buffer between demand and supply. Constraints for minimal changes in equipment load and operational parameters are established for smooth regulation. Industrial cases demonstrate that the load forecasting model has mean absolute percentage errors of 2.44% and 1.68% for medium-pressure and low-pressure steam, respectively, meeting accuracy requirements. The modified supply-side load smoothness is effectively improved by considering heat network elasticity. The method increases boiler efficiency by 1.92%, reducing average coal consumption by 0.92 t/h. Compared to manual operation, the proposed model leads to an average increase of 5.69 MW in power generation and an average reduction of 10.81% in coal-to-electricity ratio. This study verifies the importance of smooth integration across different levels and analyzes the effective response of the proposed method to the uncertainty in load forecasting. The method demonstrates the enormous potential of data-driven methods in achieving safe, economical, and sustainable production in industrial parks.
