Seismic waves from a magnitude 8.3 earthquake in Japan were consistently recorded by five nearly identical gPhone gravity meters in Colorado. Good correlation was also found in the response of two different types of g...Seismic waves from a magnitude 8.3 earthquake in Japan were consistently recorded by five nearly identical gPhone gravity meters in Colorado. Good correlation was also found in the response of two different types of gravity meters and a standard seismometer in Walferdange, Luxembourg to an earthquake of magnitude 8.2 in Japan, indicating that all of them were capable of measuring the surface waves reliably. The gravity meters, however, recorded 11 separate arrivals of Raleigh waves, while the seismometer only one. Thus the gravity meters may be useful for obtaining new information in the study of seismic velocities, attenuation and dispersion.展开更多
Kick and loss are two complicated incidents that affect the construction safety in oil and gas well drilling.The commonly-used kick/loss monitoring methods are disadvantageous with monitoring lag and low metering prec...Kick and loss are two complicated incidents that affect the construction safety in oil and gas well drilling.The commonly-used kick/loss monitoring methods are disadvantageous with monitoring lag and low metering precision,which may cause well collapse,pipe sticking and well blowouts due to untimely detection and improper treatment.In this paper,a new type of kick/loss monitoring and metering system was designed based upon a comparative analysis of several kick/loss monitoring methods commonly used on rig sites.This new system has the functions of early monitoring and alarm,kick/loss velocity metering,total loss metering and automatic filling,and its feasibility was verified through laboratory experiments.And the following research results were obtained.First,the monitoring tank of this new system is divided into two chambers,i.e.,a main chamber and a secondary chamber.The return of drilling fluid partially flows back to the shale shaker through the main chamber,and the rest overflows into the secondary chamber.Second,the internal cross section area of the secondary chamber is small,which increases the response sensitivity to liquid level change,so kick/loss can be detected in time.Third,the water head of the outlet pipeline of the main chamber remains constant and the outlet flow is stable,so kick/loss velocity and total kick/loss can be calculated quantitatively based on the change of liquid level in the secondary chamber.And the monitoring error of kick/loss velocity is less than 8%.Fourth,in the process of tripping out,the drilling fluid in the monitoring tank flows into the wellbore under the action of self weight to keep the full liquid level of the wellbore all the time.As a result,lagged filling and partial filling are eliminated.In conclusion,this new kick/loss monitoring system is economical and practical,and giving a full play to the advantages of ground survey and alarm timely and accurately.展开更多
This study presents the results of the preliminary tests performed using a kerma-area product (KAP) meter in order to verify its usefulness as a monitor chamber in a clinical X ray system, which will be used in ioniza...This study presents the results of the preliminary tests performed using a kerma-area product (KAP) meter in order to verify its usefulness as a monitor chamber in a clinical X ray system, which will be used in ionization chambers’ quality control program. The tests performed were repeatability, surface measurement uniformity, linearity with tube current, measurement variation changing the distance and field size, KAP chamber radiation attenuation, and energy dependence. The KAP meter has presented a good repeatability (a maximum variation of 0.4%);its surface has a homogeneous response (a maximum variation of 1.0% among the different irradiated regions);the response is linear with the tube current and the variation of the PKA along the distance is less than 3.43%. On the other hand, the results obtained for chamber attenuation and energy dependence show that some corrections must be applied when the measurements are made. The results have shown a good performance of the KAP meter, confirming that it is possible to use this instrument as a monitor chamber. However, it is important to highlight that some correction factors for energy dependence and chamber radiation attenuation must be considered.展开更多
电力计量装置运行状态监测对保障电网安全运行具有重要意义。针对传统监测系统存在的时延高、准确率低等问题,构建基于5G的电力计量装置运行状态异常监测系统。该系统采用3层架构设计,底层部署多种传感器实时采集数据,中间层利用5G构建...电力计量装置运行状态监测对保障电网安全运行具有重要意义。针对传统监测系统存在的时延高、准确率低等问题,构建基于5G的电力计量装置运行状态异常监测系统。该系统采用3层架构设计,底层部署多种传感器实时采集数据,中间层利用5G构建低时延、高可靠链路,上层运行改进的孤立森林算法进行异常判定。实验结果表明,该系统在较差网络环境下仍保持95.2%的检测准确率,平均检测时延不超过485 ms,误报率和数据包丢失率分别低至0.92%和0.024%,远优于传统通用分组无线业务(General Packet Radio Service,GPRS)系统。展开更多
文摘Seismic waves from a magnitude 8.3 earthquake in Japan were consistently recorded by five nearly identical gPhone gravity meters in Colorado. Good correlation was also found in the response of two different types of gravity meters and a standard seismometer in Walferdange, Luxembourg to an earthquake of magnitude 8.2 in Japan, indicating that all of them were capable of measuring the surface waves reliably. The gravity meters, however, recorded 11 separate arrivals of Raleigh waves, while the seismometer only one. Thus the gravity meters may be useful for obtaining new information in the study of seismic velocities, attenuation and dispersion.
基金supported by the National Major Science and Technology Project"Drilling and Completion Technology for Efficient Development of Low Permeability Oil and Gas Reservoirs-Key Tools and Equipment for Drilling Speed Enhancement and Efficiency Improvement in Complex Formations"(No.:2016ZX05021-003).
文摘Kick and loss are two complicated incidents that affect the construction safety in oil and gas well drilling.The commonly-used kick/loss monitoring methods are disadvantageous with monitoring lag and low metering precision,which may cause well collapse,pipe sticking and well blowouts due to untimely detection and improper treatment.In this paper,a new type of kick/loss monitoring and metering system was designed based upon a comparative analysis of several kick/loss monitoring methods commonly used on rig sites.This new system has the functions of early monitoring and alarm,kick/loss velocity metering,total loss metering and automatic filling,and its feasibility was verified through laboratory experiments.And the following research results were obtained.First,the monitoring tank of this new system is divided into two chambers,i.e.,a main chamber and a secondary chamber.The return of drilling fluid partially flows back to the shale shaker through the main chamber,and the rest overflows into the secondary chamber.Second,the internal cross section area of the secondary chamber is small,which increases the response sensitivity to liquid level change,so kick/loss can be detected in time.Third,the water head of the outlet pipeline of the main chamber remains constant and the outlet flow is stable,so kick/loss velocity and total kick/loss can be calculated quantitatively based on the change of liquid level in the secondary chamber.And the monitoring error of kick/loss velocity is less than 8%.Fourth,in the process of tripping out,the drilling fluid in the monitoring tank flows into the wellbore under the action of self weight to keep the full liquid level of the wellbore all the time.As a result,lagged filling and partial filling are eliminated.In conclusion,this new kick/loss monitoring system is economical and practical,and giving a full play to the advantages of ground survey and alarm timely and accurately.
文摘This study presents the results of the preliminary tests performed using a kerma-area product (KAP) meter in order to verify its usefulness as a monitor chamber in a clinical X ray system, which will be used in ionization chambers’ quality control program. The tests performed were repeatability, surface measurement uniformity, linearity with tube current, measurement variation changing the distance and field size, KAP chamber radiation attenuation, and energy dependence. The KAP meter has presented a good repeatability (a maximum variation of 0.4%);its surface has a homogeneous response (a maximum variation of 1.0% among the different irradiated regions);the response is linear with the tube current and the variation of the PKA along the distance is less than 3.43%. On the other hand, the results obtained for chamber attenuation and energy dependence show that some corrections must be applied when the measurements are made. The results have shown a good performance of the KAP meter, confirming that it is possible to use this instrument as a monitor chamber. However, it is important to highlight that some correction factors for energy dependence and chamber radiation attenuation must be considered.
文摘电力计量装置运行状态监测对保障电网安全运行具有重要意义。针对传统监测系统存在的时延高、准确率低等问题,构建基于5G的电力计量装置运行状态异常监测系统。该系统采用3层架构设计,底层部署多种传感器实时采集数据,中间层利用5G构建低时延、高可靠链路,上层运行改进的孤立森林算法进行异常判定。实验结果表明,该系统在较差网络环境下仍保持95.2%的检测准确率,平均检测时延不超过485 ms,误报率和数据包丢失率分别低至0.92%和0.024%,远优于传统通用分组无线业务(General Packet Radio Service,GPRS)系统。
