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周期性轴对称凹槽结构隔声特性数值模拟   总被引:4,自引:0,他引:4  
提出一种在钻铤上切割周期性轴对称凹槽方式构建隔声体,消除钻铤模式波的方法.结果表明,其隔声效果与凹槽深度H、长度L、凹槽数目N、凹槽截面形状以及钻铤壁厚有关.选择矩形截面凹槽、减小钻铤壁厚、增加凹槽深度都可有效提高隔声体的隔声效果,该结构最高可获得约36 dB的声衰减,基本满足随钻声波测井仪器对隔声效果要求.  相似文献   
2.
孔隙网络模型广泛地用于同多孔介质有关的微观模拟中. 本文简介了利用网络模型 研究储层渗流规律的基本思想、主要步骤以及网络模型同其它微观模型相比较的优 缺点, 总结了在微观渗流研究中使用的两大类网络模型(准静态网络模型和动态网 络模型)的特征及其适用范围, 综述了目前网络模型在研究渗流中的应用现状以及 国内外研究比较活跃的几个方面,最后分析了网络模型今后的发展趋向.  相似文献   
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Spectrum analysis of natural gamma ray spectral logging (SGR) data is a critical part of surface information processing systems. Due to the low resolution, which is an inherent weakness of SGR, and the low signal-to-noise ratio problem of logging measurements, SGR is usually treated with a low confidence level. The Direct Demodulation (DD) method is an advanced technique to solve modulation equations interactively under physical constraints. It has higher sensitivity and spatial resolution than the traditional methods and can effectively suppress the logging noise. Based on standard count rate spectral data obtained from the China Offshore Oil Logging Company SGR Calibration Facility, this paper presents the application of the DD method to gamma-ray logging. The results are compared with four traditional algorithmic methods, showing that the DD method is a credible choice, with higher sensitivity and higher spatial resolution in gamma-ray log interpretation. The Point-Spread-Function of the Shengli Oil Logging Company's natural gamma ray spectroscopy instrument is obtained for the first time. The quantities of various radionuclides in their calibration pits are also obtained. The DD method was applied successfully to gamma-ray logging, offering a new option for SGR logging algorithm selection.  相似文献   
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Spectrum analysis of natural gamma ray spectral logging (SGR) data is a critical part of surface informa- tion processing systems. Due to the low resolution, which is an inherent weakness of SGR, and the low signal-to-noise ratio problem of logging measurements, SGR is usually treated with a low confidence level. The Direct Demodulation (DD) method is an advanced technique to solve modulation equations interactively under physical constraints. It has higher sensitivity and spatial resolution than the traditional methods and can effectively suppress the logging noise. Based on standard count rate spectral data obtained from the China Offshore Oil Logging Company SGR Calibration Facility, this paper presents the application of the DD method to gamma-ray logging. The results are compared with four traditional algorithmic methods, showing that the DD method is a credible choice, with higher sensitivity and higher spatial resolution in gamma-ray log interpretation. The Point-Spread-Function of the Shengli Oil Logging Company's natural gamma ray spectroscopy instrument is obtained for the first time. The quantities of various radionuclides in their calibration pits are also obtained. The DD method was applied successfully to gamma-ray logging, offering a new option for SGR logging algorithm selection.  相似文献   
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