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
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
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 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.