检索结果-南通市图书馆

Numerical simulation of an acoustic field generated by a phased arc array in a fluid-filled cased borehole

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2014年第3期11卷 385-390页

作者： che xiaohua Qiao Wenxiao Wang Ruijia Zhao Yuhong State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum Key Laboratory of Earth Prospecting and Information Technology China University of Petroleum China National Oil & Gas Exploration & Development Company

Transducers that are widely applied in cement bond evaluation tools, such as cement bond logs and variable density logs, cannot radiate acoustic energy directionally because of the characteristics of monopole sources. A phased arc array transmitter, which is a novel transducer that differs from monopole and dipole transducers, is presented in this study. To simulate the acoustic field generated by a phased arc array in a fluid-filled cased borehole with different channelings, a 3D finite-difference time-domain method is adopted. The acoustic field generated by a traditional monopole source is also simulated and compared with the field generated by the phased arc array transmitter. Numerical simulation results show that the phased arc array radiates energy directionally in a narrow angular range in the borehole, thereby compressing the acoustic energy into a narrow range in the casing pipe, the cement, and the formation. We present the analyses of first-arrival waveforms and the amplitudes of casing waves at different azimuthal angles for the two different sources. The results indicate that employing a directional source facilitates azimuthal identification and analysis of possible channeling behind the casing pipe.

关键词： Phased arc array azimuthal angle first-arrival amplitude acoustic field cased borehole

Numerical simulation of an acoustic field generated by a phased arc array in a fluid-filled borehole

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2009年第3期6卷 225-229页

作者： che xiaohua Qiao Wenxiao State Key Laboratory of Petroleum Resource and Prospecting China University of Petroleum Beijing 102249 China

The acoustic tools widely used in borehole well logging and being developed in borehole acoustic reflection imaging do not have the function of azimuthal measurement due to a symmetric source, so they can not be used to evaluate the azimuthal character of borehole formation. In this paper, a 3D finite difference method was used to simulate the acoustic fields in a fluid-filled borehole generated by a traditional monopole source and a phased arc array. Acoustic waveforms were presented for both cases. The analysis of the simulated waveforms showed that different from the monopole source, the acoustic energy generated by the phased arc array transmitter mainly radiated to the borehole in a narrow azimuthal range, which was the key technique to implement azimuthal acoustic well logging. Similar to the monopole source, the waveforms generated by the phased arc array in the fluid-filled borehole also contain compressional （P） waves and shear （S） waves refracted along the borehole, which is the theoretical foundation of phased arc array acoustic well logging.

关键词： Phased arc array acoustic field acoustic well logging azimuth finite difference method

Effects of boundary conditions on vibrating mode of acoustic logging dipole transducer

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2008年第S2期51卷 195-200页

作者： QIAO WenXiao,che xiaohua & ZHANG Fei State Key Laboratory of Petroleum Resource and Prospecting,China University of Petroleum,Beijing 102249,China State Key Laboratory of Petroleum Resource and Prospecting China University of Petroleum Beijing China

Acoustic transducer is an important part of acoustic well logging tool. In this paper,ANSYS software package is used to design acoustic dipole transducer and simulate vibrating mode of the dipole transducer in different mechanical boundary conditions. The results show that boundary conditions influence the number of vibrating mode in the same frequency band and the frequency value of the same vibrating mode. Several acoustic dipole transducers are designed according to the results of numerical simulation and laboratory measurements. The basic frequency of vibrating mode of experi-ment has good agreement with that of simulation. The numerical simulation plays a good guidance role in designing,producing and correctly installing the acoustic dipole transducer.

关键词： acoustic dipole transducer vibrating mode basic frequency acoustic well logging

Numerical study on scanning radiation acoustic field in formations generated from a borehole

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2005年第2期48卷 247-256页

作者： che xiaohua1, ZHANG Hailan1, QIAO Wenxiao2 & JU Xiaodong2 1. Institute of Acoustics, Chinese Academy of Sciences, Beijing 100080, China 2. Faculty of Natural Resources & Information Technology, University of Petroleum, Beijing 102249, China Institute of Acoustics Chinese Academy of Sciences Beijing China Faculty of Natural Resources & Information Technology University of Petroleum Beijing China

Numerical study on scanning radiation acoustic field in formations generated by linear phased array transmitters in a fluid-filled borehole is carried out using a real axis integration (RAI) method. The main lobe width of the acoustic beams and the incident angle on the borehole wall can be controlled by means of adjusting parameters, such as the element number and the delay time between the neighboring array elements of linear phased array transmitter. The steered angle of longitudinal waves generated in the formation satisfies the Snell’s law for plane waves when the incident angle on the borehole wall is less than the first critical angle. When the lobe width of the acoustic beams is narrow and the steered angle is less than the first critical angle, the acoustic field in the formation can be approximately calculated given that the linear phased array is put in the formation without borehole. The technique of scanning radiation acoustic field can be applied to enhancing investigation resolution and signal-to-noise ratio in crosswell seismic survey and borehole acoustic reflection imaging.

关键词： formation, linear phased array transmitter, steered angle, RAI, scanning radiation.

在线全文

学校读者我要写书评

暂无评论

声波测井高灵敏度宽带接收器研究

中国石油大学学报（自然科学版） 2014年第6期38卷 54-60页

作者：吴金平乔文孝车小花中国石油大学油气资源与探测国家重点实验室北京102249 中国石油大学地球探测与信息技术重点实验室北京102249

采用有限元法与实验测量相结合对可应用于声波测井的高灵敏度宽带接收器进行研究。通过 ANSYS 对接收器的优化分析表明,接收器的性能主要受陶瓷片长度和厚度的影响,减少陶瓷片长度有利于拓宽工作频带,增加陶瓷片厚度有利于提高接收灵敏... 详细信息

采用有限元法与实验测量相结合对可应用于声波测井的高灵敏度宽带接收器进行研究。通过 ANSYS 对接收器的优化分析表明,接收器的性能主要受陶瓷片长度和厚度的影响,减少陶瓷片长度有利于拓宽工作频带,增加陶瓷片厚度有利于提高接收灵敏度。优化后接收器的性能指标如下：接收器的工作频率为1-30 kHz,频带内接收灵敏度平均值为-204.85 dB,灵敏度起伏量小于2.3 dB。在此基础上,加工制作接收器并进行实验测试,测试结果与计算结果基本吻合,证实了接收器具有高灵敏度、宽频带的特点。

关键词：声波测井接收器工作频率接收灵敏度

在线全文

学校读者我要写书评

暂无评论

主动调Q次级拉曼模激光器的研究

光学学报 2020年第6期40卷 95-103页

作者：车潇华徐杰李恒达丁双红烟台大学光电信息科学技术学院山东烟台264005

利用主动调Q的自拉曼激光器,抑制主要频移拉曼模,使次级拉曼模受激拉曼散射输出新波长的拉曼光。首先,进行理论推导得到包含两个拉曼项的主动调Q归一化速率方程,由典型的实验装置参数和常用晶体参数对归一化拉曼增益系数、归一化损耗比... 详细信息

利用主动调Q的自拉曼激光器,抑制主要频移拉曼模,使次级拉曼模受激拉曼散射输出新波长的拉曼光。首先,进行理论推导得到包含两个拉曼项的主动调Q归一化速率方程,由典型的实验装置参数和常用晶体参数对归一化拉曼增益系数、归一化损耗比、归一化初始反转粒子数进行取值。其次,通过数值模拟研究归一化参量对两束拉曼光脉冲的影响,找到可以实现次级拉曼模受激拉曼散射的参量取值范围。最后,利用实验参数计算得到的归一化变量值进行数值模拟,对结果进行分析并给出优化方案。

关键词：激光器次级拉曼模拉曼激光器速率方程数值模拟

TI地层声学各向异性随钻评价方法的数值研究

在线全文

学校读者我要写书评

暂无评论

中国石油大学学报（自然科学版） 2014年第4期38卷 65-73页

作者：王瑞甲乔文孝车小花鞠晓东中国石油大学油气资源与探测国家重点实验室北京102249 中国石油大学北京市地球探测与信息技术重点实验室北京102249

采用三维有限差分方法模拟偶极子声源在含钻铤的各向异性地层井孔中激发的声场,研究地层各向异性对偶极模式波频散特征的影响,并提出从随钻四分量偶极子声波数据中提取地层快、慢横波慢度及其各向异性的方法。结果表明,偶极子声源在各... 详细信息

采用三维有限差分方法模拟偶极子声源在含钻铤的各向异性地层井孔中激发的声场,研究地层各向异性对偶极模式波频散特征的影响,并提出从随钻四分量偶极子声波数据中提取地层快、慢横波慢度及其各向异性的方法。结果表明,偶极子声源在各种地层井孔中均可激发对横波慢度的方位各向异性敏感的偶极模式波:对于快速地层,F2模式的低频部分对地层横波慢度及其方位各向异性最为敏感;对于中速和慢速地层,弯曲波较高频率部分对地层横波慢度较为敏感。采用各向同性地层建模的方法可以较为准确地提取地层的快、慢横波慢度,提取结果的误差小于4%。

关键词：随钻测井声波测井各向异性偶极子

利用流-固交界面上的伪瑞利波幅度进行液位检测的实验测量

在线全文

学校读者我要写书评

暂无评论

声学学报 2014年第5期39卷 633-638页

作者：刘拓乔文孝车小花段文星赵玉宏中国石油大学油气资源与探测国家重点实验室北京102249 北京市地球探测与信息技术重点实验室北京102249 中国石油海外勘探开发公司北京100044

基于流-固交界面上的伪瑞利波衰减依赖半空间流体性质这一特点,提出了一种利用伪瑞利波幅度测量液位的声学方法,并设计实验对其可行性进行了探讨。首先简要介绍了该方法的理论基础,回顾了前一篇文章的数值模拟工作所得到的重要结论;而... 详细信息

基于流-固交界面上的伪瑞利波衰减依赖半空间流体性质这一特点,提出了一种利用伪瑞利波幅度测量液位的声学方法,并设计实验对其可行性进行了探讨。首先简要介绍了该方法的理论基础,回顾了前一篇文章的数值模拟工作所得到的重要结论;而后在水槽内进行实验,使用两个源距固定的横波换能器分别激发和接收铝制柱体表面的伪瑞利波,测量了不同液面高度下的脉冲伪瑞利波幅度及其主频偏移,并与数值模拟结果进行了比较。实验结果表明,测量所得的伪瑞利波幅度变化范围略小于数值模拟所得到的结果,但二者在反映变化规律上具有较好的一致性,即:随着液面高度的升高,脉冲伪瑞利波幅度近似呈指数下降,与此同时主频向低频偏移,偏移量近似呈线性规律增大。本文的研究结果从实验上验证了这一检测方法的可行性和有效性。

关键词：伪瑞利波实验测量幅度测量液位检测交界面利用数值模拟液面高度

在线全文

学校读者我要写书评

暂无评论

多极子声波测井的裂缝识别与评价

石油与天然气地质 2020年第6期41卷 1263-1272页

作者：车小花赵腾乔文孝吕文雅樊建明中国石油大学(北京)油气资源与探测国家重点实验室北京102249 北京市地球探测与信息技术重点实验室北京102249 中国石油长庆油田分公司勘探开发研究院陕西西安710021

多极子声波测井在油田应用广泛,对地层裂缝进行评估和分析是其一个重要应用。简要介绍了多极子声波测井在裂缝识别中的国内外研究现状,并简述了多种现有的利用多极子声波测井资料评价裂缝的新方法。以鄂尔多斯盆地X井区实际的多极子声... 详细信息

多极子声波测井在油田应用广泛,对地层裂缝进行评估和分析是其一个重要应用。简要介绍了多极子声波测井在裂缝识别中的国内外研究现状,并简述了多种现有的利用多极子声波测井资料评价裂缝的新方法。以鄂尔多斯盆地X井区实际的多极子声波测井资料处理为例,利用纵横波时差比判断裂缝倾角、井孔模式波声衰减判断裂缝倾角和有效性、斯通利波反射系数确定裂缝位置。利用横波时差各向异性和快慢横波频谱差异估计裂缝发育程度、快横波面方位确定裂缝走向。结合实际电成像测井资料进行了进一步的对比和验证,并对上述方法在裂缝评价中的作用与干扰因素进行了归纳总结。综合应用多种方法进行裂缝识别,可以获取更多的裂缝参数,克服单一方法的部分多解性,从而使基于多极子声波资料的裂缝评价更加准确合理。

关键词：声衰减斯通利波反射系数纵横波时差比各向异性多极子声波测井裂缝评价