To the Editor:Postoperative organ injuries and complications are the leading causes of perioperative morbidity and mortality.Although many retrospective studies have revealed the association between intraoperative hyp...To the Editor:Postoperative organ injuries and complications are the leading causes of perioperative morbidity and mortality.Although many retrospective studies have revealed the association between intraoperative hypotension and perioperative organ injury,[1]the results of prospective randomized trials with regard to tight blood pressure management and clinical outcomes were inconsistent.[2–4]Organ injury could be also provoked by surgery-induced stress.Dexmedetomidine has been validated to attenuate the over-expression of stress mediators;however,whether perioperative dexmedetomidine can improve clinical outcomes remains uncertain.[5,6]Therefore,this 2×2 factorial randomized trial was designed to investigate whether targeted blood pressure management with/without dexmedetomidine administration could minimize the occurrence of a composite of major organ injuries and complications within 30 days in moderateto-high risk patients after major non-cardiac surgery.展开更多
Objective:To explore the application of“tertiary hospitals-secondary hospitals and nursing care institutions-community-family”four-dimensional linkage care model in peritoneal dialysis patients.Methods:99 cases of p...Objective:To explore the application of“tertiary hospitals-secondary hospitals and nursing care institutions-community-family”four-dimensional linkage care model in peritoneal dialysis patients.Methods:99 cases of peritoneal dialysis patients were divided into 47 cases in the control group and 52 cases in the intervention group.In the control group,the routine discharge follow-up model was adopted;in the intervention group,the hospital-led medical unit was adopted as the basis of the“tertiary hospitals-secondary hospitals and nursing care institutions-community-family”quadruple linkage care model,and the patients’systolic blood pressure was compared with those in the control group before and after discharge.The systolic blood pressure,diastolic blood pressure,N-terminal brain natriuretic peptide,and sodium were compared between the two groups.Results:The systolic blood pressure,diastolic blood pressure,N-terminal brain natriuretic peptide,and blood sodium of patients in the intervention group were significantly better than those of the control group(all P<0.001).Conclusion:Based on the“tertiary hospital-secondary hospital and nursing home-community-family”quadratic care model,the blood pressure control rate of elderly peritoneal dialysis patients can be increased to meet the standard,reduce the symptoms of the disease,and improve the satisfaction.展开更多
Dear Editor,The primary objective of the letter is to emphasize the importance of personalized management of arterial blood pressure(ABP)in the context of off-pump coronary artery bypass grafting(CABG)surgery.Coronary...Dear Editor,The primary objective of the letter is to emphasize the importance of personalized management of arterial blood pressure(ABP)in the context of off-pump coronary artery bypass grafting(CABG)surgery.Coronary artery disease,a leading global cause of mortality,necessitates a substantial number of cardiac surgeries,with approximately 400,000 CABG operations conducted annually in the United States.Postoperative heart failure(HF)is a common occurrence after CABG surgery,with readmission rates within 30 d due to HF ranging from 12% to 16%.展开更多
During deepwater managed pressure drilling(MPD),the gas kick may occur in abnormally high-pressure formations.If the traditional well control method is adopted,the treatment time is long and the advantage of early gas...During deepwater managed pressure drilling(MPD),the gas kick may occur in abnormally high-pressure formations.If the traditional well control method is adopted,the treatment time is long and the advantage of early gas kick detection of MPD is lost.The dynamic managed pressure well-control(MPWC)method can be used to rapidly treat gas kick in deepwater MPD.In this paper,considering the effect of large-variable-diameter annulus and complex wellbore temperature in deepwater drilling,a simplified model of non-isothermal gas-liquid two-phase flow was established for dynamic deepwater MPWC simulation.Using this model,the response characteristics of outlet flow and wellhead backpressure were investigated.The results indicated that the gas fraction,outlet liquid flow rate,pit gain and wellhead backpressure presented complex alternating characteristics when gas moved upwards in the wellbore due to the large-variable-diameter annulus.The outlet liquid flow rate would be lower than the inlet flow rate and the pit gain would decrease before the gas moved to the wellhead.The variation trend of the wellhead backpressure was consistent with that of the pit gain.When the gas-liquid mixture passed through the choke,the expansion or compression of the gas caused part of the choke pressure drop to be supplemented or unloaded,delaying the response rate of the wellhead backpressure.The wellbore temperature,borehole diameter and seawater depth had different effects on outlet flow rate,pit gain and wellhead backpressure.This research could provide a new idea for well control methods in deepwater managed pressure drilling.展开更多
Fractured carbonate reservoirs are susceptible to blowout and lost circulation during drilling,which not only restricts drilling speed,but also poses big threat to well control.Moreover,there are few technical means a...Fractured carbonate reservoirs are susceptible to blowout and lost circulation during drilling,which not only restricts drilling speed,but also poses big threat to well control.Moreover,there are few technical means available to reconstruct pressure balance in the borehole.Accordingly,the fine managed pressure drilling was used in the drilling of Well GS19 in the Qixia Formation with super-high pressure and narrow density window,which is a success:①back pressure in the annular spaces will be adjusted to maintain a slightly over-balanced bottom-hole hydraulic pressure,and fluid level in the circulation tank will be kept in a slight dropping state to ensure that natural gas in the formation would not invade into the borehole in a massive volume;②inlet drilling fluid density will be controlled at around 2.35 g/cm^(3),back pressures in the annular be maintained at 2-5 MPa,and bottom-hole pressure equivalent circulation density be controlled at 2.46-2.52 g/cm^(3);③during managed pressure drilling operations,if wellhead pressure exceeds or expects to exceed 7 MPa,semi-blind rams will be closed.Fluids will pass through the choke manifold of the rig to the choke manifold specifically for pressure control before entering gas/liquid separators to discharge gas;④during tripping back pressure will be kept at less than 5 MPa,volume of injected drilling fluid will be higher than the theoretical volume during tripping out,whereas the volume of returned drilling fluid will be higher than the theoretical volume during the out-tripping.This technique has been applied successfully in the drilling of the Qixia Formation,Liangshan Formation and Longmaxi Formation with a total footage of 216.60 m,as a good attempt in complicated wells with both blowout and lost circulation risks,which can provide valuable experiences and guidance for handling similar complexities in the future.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
When gas invasion,especially overflow,occurs at the bottom hole in the process of managed pressure drilling(MPD),it is common to apply backpressure on the wellbore by adjusting the backpressure pump and throttle valve...When gas invasion,especially overflow,occurs at the bottom hole in the process of managed pressure drilling(MPD),it is common to apply backpressure on the wellbore by adjusting the backpressure pump and throttle valve,so as to rebuild bottom hole pressure balance.If it is still thought that the wellhead backpressure is loaded to the bottom hole instantaneously,there will be larger errors between the calculated wellbore parameters and the actual wellbore flow parameters,which will result in well control failure and even well blowout.In this paper,a pressure wave propagation equation suitable for the gaseliquid two-phase flow in the annulus was established based on the global averaged gaseliquid two-phase flow model to investigate the propagation velocity and time of backpressure wave in the wellbore.Then,gaseliquid interaction was introduced to carry out coupling solution on the equation set.It is shown that pressure wave velocity increases with the increase of drilling mud density,but decreases with the increase of void fraction and virtual mass force coefficient.It changes drastically at first,and then slows down.What's more,when the void fraction is greater than 0.1 or the virtual mass force coefficient exceeds 0.2,the momentum between gas phase and liquid phase is fully exchanged,and the pressure wave velocity decreases slowly,approaching a stable value.In Well Penglai 9 in the Sichuan Basin,for example,the average time of single pressure wave propagation is about 50 s,and the total propagation time of 4 rounds is about 200 s,which accounts for more than 67%of the total time of system control response.It is indicated that the propagation velocity and time of the pressure wave in the annulus calculated by this method can greatly improve the accuracy of managed pressure response time of MPD drilling system and the control precision of adaptive throttle valve.展开更多
Irbesartan-hydrochlorothiazide is a commonly used antihypertensive drug,but potential adverse reactions such as hypokalemia should not be overlooked.This study analyzes a case of hypokalemia induced by irbesartan-hydr...Irbesartan-hydrochlorothiazide is a commonly used antihypertensive drug,but potential adverse reactions such as hypokalemia should not be overlooked.This study analyzes a case of hypokalemia induced by irbesartan-hydrochlorothiazide,exploring the drug’s association with hypokalemia and clinical treatment strategies.The patient experienced symptoms of muscle weakness and palpitations after taking irbesartan-hydrochlorothiazide and was diagnosed with hypokalemia through laboratory tests.Reviewing the patient’s medication history and disease progression,it was hypothesized that the drug’s potassium-wasting effect was the direct cause of the hypokalemia.After discontinuing the medication and initiating potassium supplementation,the patient’s potassium levels returned to normal,and symptoms significantly improved,further confirming the link between hypokalemia and the medication.This case suggests that clinicians should consider the risk of hypokalemia when treating hypertension,especially in patients with chronic kidney disease,the elderly,or those at risk for electrolyte disturbances.For patients who have already developed hypokalemia,potassium supplementation and adjustment of the treatment regimen are recommended to prevent further deterioration.Timely discontinuation of potential causative drugs is also advised.In summary,ensuring medication safety and preventing potential complications has significant clinical importance in recognizing and managing hypokalemia induced by irbesartan-hydrochlorothiazide.Future research should focus on optimizing treatment protocols and developing more effective strategies for preventing and managing related adverse reactions to improve patient quality of life.展开更多
The study considers gas compression properties,gas slippage,back pressure(BP),phase transition(PT),well depth,and differences in gas-liquid physical properties.A new temperature model for multiphase flow is proposed b...The study considers gas compression properties,gas slippage,back pressure(BP),phase transition(PT),well depth,and differences in gas-liquid physical properties.A new temperature model for multiphase flow is proposed by considering phase transition in the drilling process.The mathematical model of multiphase flow is solved using the finite difference method with annulus mesh division for grid nodes,and a module for multiphase flow calculation and analysis is developed.Numerical results indicate that the temperature varies along the annulus with the variation of gas influx at the bottom of the well.During the process of controlled pressure drilling,as gas slips along the annulus to the wellhead,its volume continuously expands,leading to an increase in the gas content within the annulus,and consequently,an increase in the pressure drop caused by gas slippage.The temperature increases with the increase in BP and decreases in gas influx rate and wellbore diameter.During gas influx,the thermal conductivity coefficient for the gas-drilling mud two phases is significantly weakened,resulting in a considerable change in temperature along the annulus.In the context of MPD,the method of slightly changing the temperature along the annulus by controlling the back pressure is feasible.展开更多
The exploration and development of oil and gas resources in the Sichuan Basin is shifting to the deeper strata.The deep and ultra-deep wells in deep carbonate gas reservoirs are faced with many difficulties,such as mu...The exploration and development of oil and gas resources in the Sichuan Basin is shifting to the deeper strata.The deep and ultra-deep wells in deep carbonate gas reservoirs are faced with many difficulties,such as multiple pressure systems,poor drillability,ultra-high pressure,ultra-high temperature and high sulfur content,which bring great challenges to drilling and completion engineering.In order to ensure the smooth exploration and development of deep carbonate oil and gas resources in the Sichuan Basin,the overall concept of combiningfield practice and technological research is followed.During the 13th Five-Year Plan,a batch of ultra-deep wells(well depth about 8000 m)have been drilled fast and safely(such as Well SYX133 in the Shuangyushi structure),and great progresses have been achieved in the experimental research of the support technologies in drilling and completion of deep and ultra-deep wells.And the achievements are as follows.First,the optimization of non-standard well structure,combined with the application of precisely managed pressure drilling technology and under-pressure plugging technology,lays a foundation for the optimized fast drilling and the safe reaching of geological targets.Second,a high-efficiency customized PDC drill bit is comprehensively optimized,popularized and applied,which effectively improves the average rate of penetration(ROP)in difficult-to-drill formations.Third,the development and application of drillingfluids(e.g.being resistant to high temperature of 200 C and anti-composite brine)and active under-pressure plugging technology effectively reduces downhole complexities while drilling the complex for-mations,such as high temperature and high pressure brine and circulation loss.Fourth,when precisely managed pressure drilling and precisely managed pressure cementing methods are applied in the strata with a narrow density window,multiple pressure systems and pressure sensitivity,the average drilling and completionfluid loss is reduced by more than 90%,and the complexity treatment time is cut down by more than 85%,and the cementing quality pass rate is increased by more than 20%.Fifth,the integrated application of ROP improvement technologies and tools(e.g.air drilling)results in a great reduction of drilling cycle and cost.It is concluded that the experimental research achievements provide basic support for the fast development of natural gas resources in the Anyue Gas Field,Sichuan Basin,and the great discovery of the Permian and Devonian natural gas resources in the northwestern Sichuan Basin.What's more,in order to adapt to the development of the deep natural gas(over 9000 m)in the Sichuan Basin during the 14th Five-Year Plan,it is necessary to speed up researches on drilling and completion tech-nologies in nine aspects,e.g.high-temperature downhole tools and workingfluid.展开更多
Objective:To explore the association between economic status and educational level with self-management behavior(medication adherence,controlling body weight,reducing salt intake,performing physical exercise,reducing ...Objective:To explore the association between economic status and educational level with self-management behavior(medication adherence,controlling body weight,reducing salt intake,performing physical exercise,reducing alcohol consumption,abstaining from smoking,increasing fruit and vegetable consumption)among hypertensive women in Ghana.Methods:Cross-sectional data on 598 women were collected from the Ghana Demographic and Health Survey of 2014.The association between economic status and educational level with self-management behavior was measured by logistic regression methods.Results:Mean systolic blood pressure and diastolic blood pressure were 131.4 and 86.58 mm Hg,respectively.With regard to self-management behavior,81.8%of women reported taking medication to control high blood pressure,44.4%reported controlling body weight,22.5%reported reducing salt intake,48.3%reported performing physical exercise,74.2%reported reducing alcohol consumption,74.2%reported abstaining from alcohol and smoking,and 20.2%reported consuming more fruits and vegetables.Women living in the wealthiest households had significantly higher odds of maintaining healthy weight,reducing salt intake,and exercising.Conclusion:The findings imply that socioeconomic factors may play important roles in women’s adherence to blood pressure-controlling behavior.It is therefore suggested that policy makers focus on improving women’s economic status as a strategy to encourage cardiovascular health-promoting behavior.展开更多
Solid-state batteries have garnered global attention due to their high energy density and safety,holding the potential to replace traditional lithium-ion batteries in the electric vehicle,alleviating"range anxiet...Solid-state batteries have garnered global attention due to their high energy density and safety,holding the potential to replace traditional lithium-ion batteries in the electric vehicle,alleviating"range anxiety".However,a comprehensive solid-state battery management system to complement these batteries has not yet been systematically proposed.We attempt to construct a management system for solid-state batteries based on various characteristics,considering both the demand-and supply-side.This review first introduces the advantages and disadvantages of polymer-based,oxide-based,and sulfide-based solid electrolytes,as well as anode and cathode materials with higher specific capacities and promising applications.It lists the cycling performance and safety demonstrated by assembled solid-state pouch cells.Then,we systematically analyzes the differences between all-solid-state batteries and traditional lithium-ion batteries,proposing the demands and development directions for all-solid-state battery management from multiple dimensions.Finally,we build an all-solid-state battery management system from aspects such as signal monitoring,model building,aging,and early warning of failure,which includes three parts:the electric management system,the thermal management system,and the pressure management system.This review aims to provide researchers with new insights and ideas,promoting the efficient development and industrial upgrading of battery management technology.展开更多
In order to reduce the non production time of drilling,improve the efficiency and safety of drilling,improve the economic effect of managed pressure drilling(MPD),and realize the intelligent control construction of di...In order to reduce the non production time of drilling,improve the efficiency and safety of drilling,improve the economic effect of managed pressure drilling(MPD),and realize the intelligent control construction of digital oilfield.Based on the pressure control in MPD,this paper analyzes the pressure control drilling system,takes the wellhead back pressure as the controlled parameter,calculates the mathematical model of the throttle valve according to the characteristics of the throttle valve,the basic parameters and boundary conditions of pressure control drilling,and puts forward an improved particle swarm Optimization PID neural network(IPSO-PIDNN)model.By means of remote communication,VR technology can realize remote control of field control equipment.The real-time control results of IPSO-PIDNN are compared with those of traditional PID neural network(PIDNN)and traditional Particle Swarm Optimization PID neural network(PSO-PIDNN).The results show that IPSO-PIDNN model has good self-learning characteristics,high optimization quality,high control accuracy,no overshoot,fast response and short regulation time.Thus,the advanced automatic control of bottom hole pressure in the process of MPD is realized,which provides technical guarantee for the well control safety of MPD.展开更多
基金supported by grants from the National Key Research&Development Program of China(Nos.2023YFC2506900 and 2018YFC2001800)the National High Level Hospital Clinical Research Funding(Nos.2022CR74 and 2022CR78 of Peking University First Hos pital)Braun Anesthesia Scientific Research Fund(No.BBDF-2019-004).
文摘To the Editor:Postoperative organ injuries and complications are the leading causes of perioperative morbidity and mortality.Although many retrospective studies have revealed the association between intraoperative hypotension and perioperative organ injury,[1]the results of prospective randomized trials with regard to tight blood pressure management and clinical outcomes were inconsistent.[2–4]Organ injury could be also provoked by surgery-induced stress.Dexmedetomidine has been validated to attenuate the over-expression of stress mediators;however,whether perioperative dexmedetomidine can improve clinical outcomes remains uncertain.[5,6]Therefore,this 2×2 factorial randomized trial was designed to investigate whether targeted blood pressure management with/without dexmedetomidine administration could minimize the occurrence of a composite of major organ injuries and complications within 30 days in moderateto-high risk patients after major non-cardiac surgery.
文摘Objective:To explore the application of“tertiary hospitals-secondary hospitals and nursing care institutions-community-family”four-dimensional linkage care model in peritoneal dialysis patients.Methods:99 cases of peritoneal dialysis patients were divided into 47 cases in the control group and 52 cases in the intervention group.In the control group,the routine discharge follow-up model was adopted;in the intervention group,the hospital-led medical unit was adopted as the basis of the“tertiary hospitals-secondary hospitals and nursing care institutions-community-family”quadruple linkage care model,and the patients’systolic blood pressure was compared with those in the control group before and after discharge.The systolic blood pressure,diastolic blood pressure,N-terminal brain natriuretic peptide,and sodium were compared between the two groups.Results:The systolic blood pressure,diastolic blood pressure,N-terminal brain natriuretic peptide,and blood sodium of patients in the intervention group were significantly better than those of the control group(all P<0.001).Conclusion:Based on the“tertiary hospital-secondary hospital and nursing home-community-family”quadratic care model,the blood pressure control rate of elderly peritoneal dialysis patients can be increased to meet the standard,reduce the symptoms of the disease,and improve the satisfaction.
基金supported by the National Key Technologies Research and Development Program(2021YFF1200602)the National Science Fund for Excellent Overseas Scholars(0401260011)+1 种基金the National Defense Science and Technology Innovation Fund of Chinese Academy of Sciences(c02022088)Tianjin Science and Technology Program(20JCZDJC00810).
文摘Dear Editor,The primary objective of the letter is to emphasize the importance of personalized management of arterial blood pressure(ABP)in the context of off-pump coronary artery bypass grafting(CABG)surgery.Coronary artery disease,a leading global cause of mortality,necessitates a substantial number of cardiac surgeries,with approximately 400,000 CABG operations conducted annually in the United States.Postoperative heart failure(HF)is a common occurrence after CABG surgery,with readmission rates within 30 d due to HF ranging from 12% to 16%.
基金supported by the Youth Program of National Natural Science Foundation of China(Grant No.52104012)the Key Program of the National Natural Science Foundation of China(Grant No.51734010)+2 种基金the China Postdoctoral Science Foundation(Grant No.2021M693494)Science Foundation of China University of Petroleum,Beijing(Grant No.2462020XKBH011)the Key Natural Science Projects of Scientific Research Plan in Colleges and Universities of Xinjiang Uygur Autonomous Region(Grant No.XJEDU2021I028)。
文摘During deepwater managed pressure drilling(MPD),the gas kick may occur in abnormally high-pressure formations.If the traditional well control method is adopted,the treatment time is long and the advantage of early gas kick detection of MPD is lost.The dynamic managed pressure well-control(MPWC)method can be used to rapidly treat gas kick in deepwater MPD.In this paper,considering the effect of large-variable-diameter annulus and complex wellbore temperature in deepwater drilling,a simplified model of non-isothermal gas-liquid two-phase flow was established for dynamic deepwater MPWC simulation.Using this model,the response characteristics of outlet flow and wellhead backpressure were investigated.The results indicated that the gas fraction,outlet liquid flow rate,pit gain and wellhead backpressure presented complex alternating characteristics when gas moved upwards in the wellbore due to the large-variable-diameter annulus.The outlet liquid flow rate would be lower than the inlet flow rate and the pit gain would decrease before the gas moved to the wellhead.The variation trend of the wellhead backpressure was consistent with that of the pit gain.When the gas-liquid mixture passed through the choke,the expansion or compression of the gas caused part of the choke pressure drop to be supplemented or unloaded,delaying the response rate of the wellhead backpressure.The wellbore temperature,borehole diameter and seawater depth had different effects on outlet flow rate,pit gain and wellhead backpressure.This research could provide a new idea for well control methods in deepwater managed pressure drilling.
文摘Fractured carbonate reservoirs are susceptible to blowout and lost circulation during drilling,which not only restricts drilling speed,but also poses big threat to well control.Moreover,there are few technical means available to reconstruct pressure balance in the borehole.Accordingly,the fine managed pressure drilling was used in the drilling of Well GS19 in the Qixia Formation with super-high pressure and narrow density window,which is a success:①back pressure in the annular spaces will be adjusted to maintain a slightly over-balanced bottom-hole hydraulic pressure,and fluid level in the circulation tank will be kept in a slight dropping state to ensure that natural gas in the formation would not invade into the borehole in a massive volume;②inlet drilling fluid density will be controlled at around 2.35 g/cm^(3),back pressures in the annular be maintained at 2-5 MPa,and bottom-hole pressure equivalent circulation density be controlled at 2.46-2.52 g/cm^(3);③during managed pressure drilling operations,if wellhead pressure exceeds or expects to exceed 7 MPa,semi-blind rams will be closed.Fluids will pass through the choke manifold of the rig to the choke manifold specifically for pressure control before entering gas/liquid separators to discharge gas;④during tripping back pressure will be kept at less than 5 MPa,volume of injected drilling fluid will be higher than the theoretical volume during tripping out,whereas the volume of returned drilling fluid will be higher than the theoretical volume during the out-tripping.This technique has been applied successfully in the drilling of the Qixia Formation,Liangshan Formation and Longmaxi Formation with a total footage of 216.60 m,as a good attempt in complicated wells with both blowout and lost circulation risks,which can provide valuable experiences and guidance for handling similar complexities in the future.
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Project supported by General Program of National Natural Science Foundation of China“Wellbore Multi-phase Flow Coupling Mechanism Research-Formations Based on Precise Backpressure Control”(No.:51474073)“Research on Wellbore Temperature Field and Pressure Field Distribution Laws of Deep Unbalanced Drilling Based on Thermal-fluid Coupling”(No.:51374077).
文摘When gas invasion,especially overflow,occurs at the bottom hole in the process of managed pressure drilling(MPD),it is common to apply backpressure on the wellbore by adjusting the backpressure pump and throttle valve,so as to rebuild bottom hole pressure balance.If it is still thought that the wellhead backpressure is loaded to the bottom hole instantaneously,there will be larger errors between the calculated wellbore parameters and the actual wellbore flow parameters,which will result in well control failure and even well blowout.In this paper,a pressure wave propagation equation suitable for the gaseliquid two-phase flow in the annulus was established based on the global averaged gaseliquid two-phase flow model to investigate the propagation velocity and time of backpressure wave in the wellbore.Then,gaseliquid interaction was introduced to carry out coupling solution on the equation set.It is shown that pressure wave velocity increases with the increase of drilling mud density,but decreases with the increase of void fraction and virtual mass force coefficient.It changes drastically at first,and then slows down.What's more,when the void fraction is greater than 0.1 or the virtual mass force coefficient exceeds 0.2,the momentum between gas phase and liquid phase is fully exchanged,and the pressure wave velocity decreases slowly,approaching a stable value.In Well Penglai 9 in the Sichuan Basin,for example,the average time of single pressure wave propagation is about 50 s,and the total propagation time of 4 rounds is about 200 s,which accounts for more than 67%of the total time of system control response.It is indicated that the propagation velocity and time of the pressure wave in the annulus calculated by this method can greatly improve the accuracy of managed pressure response time of MPD drilling system and the control precision of adaptive throttle valve.
文摘Irbesartan-hydrochlorothiazide is a commonly used antihypertensive drug,but potential adverse reactions such as hypokalemia should not be overlooked.This study analyzes a case of hypokalemia induced by irbesartan-hydrochlorothiazide,exploring the drug’s association with hypokalemia and clinical treatment strategies.The patient experienced symptoms of muscle weakness and palpitations after taking irbesartan-hydrochlorothiazide and was diagnosed with hypokalemia through laboratory tests.Reviewing the patient’s medication history and disease progression,it was hypothesized that the drug’s potassium-wasting effect was the direct cause of the hypokalemia.After discontinuing the medication and initiating potassium supplementation,the patient’s potassium levels returned to normal,and symptoms significantly improved,further confirming the link between hypokalemia and the medication.This case suggests that clinicians should consider the risk of hypokalemia when treating hypertension,especially in patients with chronic kidney disease,the elderly,or those at risk for electrolyte disturbances.For patients who have already developed hypokalemia,potassium supplementation and adjustment of the treatment regimen are recommended to prevent further deterioration.Timely discontinuation of potential causative drugs is also advised.In summary,ensuring medication safety and preventing potential complications has significant clinical importance in recognizing and managing hypokalemia induced by irbesartan-hydrochlorothiazide.Future research should focus on optimizing treatment protocols and developing more effective strategies for preventing and managing related adverse reactions to improve patient quality of life.
基金support by the financial support of the National Nature Science Foundation of China(No.52274001,No.52074018)China Petrochemical Corporation(No.p21069)The financial support of Fundamental Research Funds for the Central Universities(buctrc202017)。
文摘The study considers gas compression properties,gas slippage,back pressure(BP),phase transition(PT),well depth,and differences in gas-liquid physical properties.A new temperature model for multiphase flow is proposed by considering phase transition in the drilling process.The mathematical model of multiphase flow is solved using the finite difference method with annulus mesh division for grid nodes,and a module for multiphase flow calculation and analysis is developed.Numerical results indicate that the temperature varies along the annulus with the variation of gas influx at the bottom of the well.During the process of controlled pressure drilling,as gas slips along the annulus to the wellhead,its volume continuously expands,leading to an increase in the gas content within the annulus,and consequently,an increase in the pressure drop caused by gas slippage.The temperature increases with the increase in BP and decreases in gas influx rate and wellbore diameter.During gas influx,the thermal conductivity coefficient for the gas-drilling mud two phases is significantly weakened,resulting in a considerable change in temperature along the annulus.In the context of MPD,the method of slightly changing the temperature along the annulus by controlling the back pressure is feasible.
基金supported by the National Research Council of Science and Technology Major Project“Sichuan Basin Large-scale Carbonate Cas Fiekd Development Demonstration Project”(No.:2016ZX05052).
文摘The exploration and development of oil and gas resources in the Sichuan Basin is shifting to the deeper strata.The deep and ultra-deep wells in deep carbonate gas reservoirs are faced with many difficulties,such as multiple pressure systems,poor drillability,ultra-high pressure,ultra-high temperature and high sulfur content,which bring great challenges to drilling and completion engineering.In order to ensure the smooth exploration and development of deep carbonate oil and gas resources in the Sichuan Basin,the overall concept of combiningfield practice and technological research is followed.During the 13th Five-Year Plan,a batch of ultra-deep wells(well depth about 8000 m)have been drilled fast and safely(such as Well SYX133 in the Shuangyushi structure),and great progresses have been achieved in the experimental research of the support technologies in drilling and completion of deep and ultra-deep wells.And the achievements are as follows.First,the optimization of non-standard well structure,combined with the application of precisely managed pressure drilling technology and under-pressure plugging technology,lays a foundation for the optimized fast drilling and the safe reaching of geological targets.Second,a high-efficiency customized PDC drill bit is comprehensively optimized,popularized and applied,which effectively improves the average rate of penetration(ROP)in difficult-to-drill formations.Third,the development and application of drillingfluids(e.g.being resistant to high temperature of 200 C and anti-composite brine)and active under-pressure plugging technology effectively reduces downhole complexities while drilling the complex for-mations,such as high temperature and high pressure brine and circulation loss.Fourth,when precisely managed pressure drilling and precisely managed pressure cementing methods are applied in the strata with a narrow density window,multiple pressure systems and pressure sensitivity,the average drilling and completionfluid loss is reduced by more than 90%,and the complexity treatment time is cut down by more than 85%,and the cementing quality pass rate is increased by more than 20%.Fifth,the integrated application of ROP improvement technologies and tools(e.g.air drilling)results in a great reduction of drilling cycle and cost.It is concluded that the experimental research achievements provide basic support for the fast development of natural gas resources in the Anyue Gas Field,Sichuan Basin,and the great discovery of the Permian and Devonian natural gas resources in the northwestern Sichuan Basin.What's more,in order to adapt to the development of the deep natural gas(over 9000 m)in the Sichuan Basin during the 14th Five-Year Plan,it is necessary to speed up researches on drilling and completion tech-nologies in nine aspects,e.g.high-temperature downhole tools and workingfluid.
文摘Objective:To explore the association between economic status and educational level with self-management behavior(medication adherence,controlling body weight,reducing salt intake,performing physical exercise,reducing alcohol consumption,abstaining from smoking,increasing fruit and vegetable consumption)among hypertensive women in Ghana.Methods:Cross-sectional data on 598 women were collected from the Ghana Demographic and Health Survey of 2014.The association between economic status and educational level with self-management behavior was measured by logistic regression methods.Results:Mean systolic blood pressure and diastolic blood pressure were 131.4 and 86.58 mm Hg,respectively.With regard to self-management behavior,81.8%of women reported taking medication to control high blood pressure,44.4%reported controlling body weight,22.5%reported reducing salt intake,48.3%reported performing physical exercise,74.2%reported reducing alcohol consumption,74.2%reported abstaining from alcohol and smoking,and 20.2%reported consuming more fruits and vegetables.Women living in the wealthiest households had significantly higher odds of maintaining healthy weight,reducing salt intake,and exercising.Conclusion:The findings imply that socioeconomic factors may play important roles in women’s adherence to blood pressure-controlling behavior.It is therefore suggested that policy makers focus on improving women’s economic status as a strategy to encourage cardiovascular health-promoting behavior.
基金funded by the National Natural Science Foundation of China(NSFC,Nos.52377211,52107230,U20A20310,and 52176199)the Fundamental Research Funds for the Central Universities.Xiaodong Wu gratefully acknowledge the financial support from the National Key R&D Program of China(No.2022YFE0207300)support from National Engineering Research Center of New Energy Vehicles and Power Systems and Shanghai Key Lab of Vehicle Aerodynamics and Vehicle Thermal Management Systems.
文摘Solid-state batteries have garnered global attention due to their high energy density and safety,holding the potential to replace traditional lithium-ion batteries in the electric vehicle,alleviating"range anxiety".However,a comprehensive solid-state battery management system to complement these batteries has not yet been systematically proposed.We attempt to construct a management system for solid-state batteries based on various characteristics,considering both the demand-and supply-side.This review first introduces the advantages and disadvantages of polymer-based,oxide-based,and sulfide-based solid electrolytes,as well as anode and cathode materials with higher specific capacities and promising applications.It lists the cycling performance and safety demonstrated by assembled solid-state pouch cells.Then,we systematically analyzes the differences between all-solid-state batteries and traditional lithium-ion batteries,proposing the demands and development directions for all-solid-state battery management from multiple dimensions.Finally,we build an all-solid-state battery management system from aspects such as signal monitoring,model building,aging,and early warning of failure,which includes three parts:the electric management system,the thermal management system,and the pressure management system.This review aims to provide researchers with new insights and ideas,promoting the efficient development and industrial upgrading of battery management technology.
基金This paper is supported by Sichuan applied basic research fund(No.2016JY0049).
文摘In order to reduce the non production time of drilling,improve the efficiency and safety of drilling,improve the economic effect of managed pressure drilling(MPD),and realize the intelligent control construction of digital oilfield.Based on the pressure control in MPD,this paper analyzes the pressure control drilling system,takes the wellhead back pressure as the controlled parameter,calculates the mathematical model of the throttle valve according to the characteristics of the throttle valve,the basic parameters and boundary conditions of pressure control drilling,and puts forward an improved particle swarm Optimization PID neural network(IPSO-PIDNN)model.By means of remote communication,VR technology can realize remote control of field control equipment.The real-time control results of IPSO-PIDNN are compared with those of traditional PID neural network(PIDNN)and traditional Particle Swarm Optimization PID neural network(PSO-PIDNN).The results show that IPSO-PIDNN model has good self-learning characteristics,high optimization quality,high control accuracy,no overshoot,fast response and short regulation time.Thus,the advanced automatic control of bottom hole pressure in the process of MPD is realized,which provides technical guarantee for the well control safety of MPD.
