The meandering channel deposit of the upper member of Neogene Guantao Formation in Shengli Chengdao extra-shallow sea oilfield is characterized by rapid change in sedimentary facies.In addition,affected by surface tid...The meandering channel deposit of the upper member of Neogene Guantao Formation in Shengli Chengdao extra-shallow sea oilfield is characterized by rapid change in sedimentary facies.In addition,affected by surface tides and sea water reverberation,the double sensor seismic data processed by conventional methods has low signal-to-noise ratio and low resolution,and thus cannot meet the needs of seismic description and oil-bearing fluid identification of thin reservoirs less than 10 meters thick in this area.The two-step high resolution frequency bandwidth expanding processing technology was used to improve the signal-to-noise ratio and resolution of the seismic data,as a result,the dominant frequency of the seismic data was enhanced from 30 Hz to 50 Hz,and the sand body thickness resolution was enhanced from 10 m to 6 m.On the basis of fine layer control by seismic data,three types of seismic facies models,floodplain,natural levee and point bar,were defined,and the intelligent horizon-facies controlled recognition technology was worked out,which had a prediction error of reservoir thickness of less than 1.5 m.Clearly,the description accuracy of meandering channel sand bodies has been improved.The probability semi-quantitative oiliness identification method of fluid by prestack multi-parameters has been worked out by integrating Poisson’s ratio,fluid factor,product of Lame parameter and density,and other prestack elastic parameters,and the method has a coincidence rate of fluid identification of more than 90%,providing solid technical support for the exploration and development of thin reservoirs in Shengli Chengdao extra-shallow sea oilfield,which is expected to provide reference for the exploration and development of similar oilfields in China.展开更多
We present an advanced schematic arrangement of the radio-wave spectrometer with a few parallel optical arms for processing the data flow. This arrangement includes two principal novelties. First of them consists in t...We present an advanced schematic arrangement of the radio-wave spectrometer with a few parallel optical arms for processing the data flow. This arrangement includes two principal novelties. First of them consists in the proposed design, where each individual optical arm exhibits its original performances providing parallel multi-band observations within a few different scales simultaneously. These optical arms have the beam shapers providing both the needed incident light polarization and apodization to increase the dynamic range. After parallel acousto-optical processing, data flows of all the optical arms are united by the joint CCD matrix on the stage of the combined electronic data processing. The second novelty is in usage of unique wide-aperture bastron-based acousto-optical cell providing one of the best performances at the middle-frequencies (about 500 MHz) in comparison with the other available crystalline materials in this range. Such multi-band capabilities have a number of applications in astrophysical scenarios at different scales: from objects in the distant universe to planetary atmospheres in the Solar system. Thus one yields the united versatile instrument, which provides comprehensive studies of astrophysical objects simultaneously with precise synchronization in various frequency ranges.展开更多
Recently,radiated electromagnetic interference(EMI)has become a research hotspot in power electronics systems,as the switching frequencies of power electronics systems have increased significantly with the adoption of...Recently,radiated electromagnetic interference(EMI)has become a research hotspot in power electronics systems,as the switching frequencies of power electronics systems have increased significantly with the adoption of wide-bandgap devices.In this article,a generalized radiated EMI model for power electronics converters with power cables is first reviewed.The radiated EMI model is then developed for a flyback power converter with critical ground impedance included.Based on the developed model,accurate high-frequency parameter extraction techniques and a radiated EMI prediction technique are developed and experimentally validated.Finally,essential measurement techniques are identified and developed to accurately extract parameters for accurate EMI prediction.The effects of the resolution bandwidth of the spectrum analyzer and critical PCB ground impedance on the radiated EMI are experimentally validated.PCB’s impact on the common-mode(CM)choke’s impedance and the radiated EMI is further validated.Techniques for minimizing the undesired near-field couplings in parameter extraction are discussed.The predicted EMI properly agreed with the measured EMI in the range of 30-230 MHz based on the EN550323 m class B standard.展开更多
基金Supported by the China National Science and Technology Major Project(2016zx05006)Sinopec Program for Science and Technology Development(P15156,P15159)。
文摘The meandering channel deposit of the upper member of Neogene Guantao Formation in Shengli Chengdao extra-shallow sea oilfield is characterized by rapid change in sedimentary facies.In addition,affected by surface tides and sea water reverberation,the double sensor seismic data processed by conventional methods has low signal-to-noise ratio and low resolution,and thus cannot meet the needs of seismic description and oil-bearing fluid identification of thin reservoirs less than 10 meters thick in this area.The two-step high resolution frequency bandwidth expanding processing technology was used to improve the signal-to-noise ratio and resolution of the seismic data,as a result,the dominant frequency of the seismic data was enhanced from 30 Hz to 50 Hz,and the sand body thickness resolution was enhanced from 10 m to 6 m.On the basis of fine layer control by seismic data,three types of seismic facies models,floodplain,natural levee and point bar,were defined,and the intelligent horizon-facies controlled recognition technology was worked out,which had a prediction error of reservoir thickness of less than 1.5 m.Clearly,the description accuracy of meandering channel sand bodies has been improved.The probability semi-quantitative oiliness identification method of fluid by prestack multi-parameters has been worked out by integrating Poisson’s ratio,fluid factor,product of Lame parameter and density,and other prestack elastic parameters,and the method has a coincidence rate of fluid identification of more than 90%,providing solid technical support for the exploration and development of thin reservoirs in Shengli Chengdao extra-shallow sea oilfield,which is expected to provide reference for the exploration and development of similar oilfields in China.
文摘We present an advanced schematic arrangement of the radio-wave spectrometer with a few parallel optical arms for processing the data flow. This arrangement includes two principal novelties. First of them consists in the proposed design, where each individual optical arm exhibits its original performances providing parallel multi-band observations within a few different scales simultaneously. These optical arms have the beam shapers providing both the needed incident light polarization and apodization to increase the dynamic range. After parallel acousto-optical processing, data flows of all the optical arms are united by the joint CCD matrix on the stage of the combined electronic data processing. The second novelty is in usage of unique wide-aperture bastron-based acousto-optical cell providing one of the best performances at the middle-frequencies (about 500 MHz) in comparison with the other available crystalline materials in this range. Such multi-band capabilities have a number of applications in astrophysical scenarios at different scales: from objects in the distant universe to planetary atmospheres in the Solar system. Thus one yields the united versatile instrument, which provides comprehensive studies of astrophysical objects simultaneously with precise synchronization in various frequency ranges.
文摘Recently,radiated electromagnetic interference(EMI)has become a research hotspot in power electronics systems,as the switching frequencies of power electronics systems have increased significantly with the adoption of wide-bandgap devices.In this article,a generalized radiated EMI model for power electronics converters with power cables is first reviewed.The radiated EMI model is then developed for a flyback power converter with critical ground impedance included.Based on the developed model,accurate high-frequency parameter extraction techniques and a radiated EMI prediction technique are developed and experimentally validated.Finally,essential measurement techniques are identified and developed to accurately extract parameters for accurate EMI prediction.The effects of the resolution bandwidth of the spectrum analyzer and critical PCB ground impedance on the radiated EMI are experimentally validated.PCB’s impact on the common-mode(CM)choke’s impedance and the radiated EMI is further validated.Techniques for minimizing the undesired near-field couplings in parameter extraction are discussed.The predicted EMI properly agreed with the measured EMI in the range of 30-230 MHz based on the EN550323 m class B standard.
