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题名	相控扫描技术在声波测井的应用
作者	车小花
学位类别	博士
答辩日期	2005
授予单位	中国科学院声学研究所
授予地点	中国科学院声学研究所
关键词	相控线阵声波辐射器 偏转角 相控扫描 实轴积分 井外地层 反射声波成像测井
其他题名	Application of Phased Array Scanning Technique in Acoustic Well logging
中文摘要	应用实轴积分方法研究了充液井孔中的相控线阵声波辐射器向井外地层扫描辐射声场的方法。给出了相控线阵声波辐射器的二维谱、充液井孔中的相控线阵声波辐射器在井孔中产生的接收信号的二维谱以及改变影响辐射器性能的参数时在井外地层中产生的声场分布特征。数值计算结果表明，改变井孔中的相控线阵声波辐射器的阵元个数、相邻阵元间激励信号的延迟时间等参数可以控制辐射声束的角宽和入射于井壁的入射角。当辐射器产生的声束以小于第一临界角的偏转角入射到井壁上时，在井外地层中产生的纵波的偏转角近似满足平面波入射于平面界面时的折射定律。当井孔中的相控线阵的辐射声束角宽较小，且声束偏转角小于第一临界角时，井外声场的空间分布可以用无井孔均匀固体的相控线阵的指向性函数直接计算。利用相控扫描技术可以提高反射声波成像测井和井间声波勘探的空间分辨率和信噪比。在变源距条件下对按比例缩小的铝质模型井进行了实验测量，从测得的声波波形上观察到了非常明显的滑行纵波和来自模型井外边界的反射纵波信号。采用定向扫描接收处理方法，分别针对滑行纵波和反射纵波进行了处理。当接收主瓣的偏转角接近于第一临界角时，声全波波形中的滑行纵波得到了加强；当接收主瓣的偏转角约为第一临界角的0.63倍时，波形中的反射纵波得到了加强。因而，采用定向扫描接收技术，调节阵列接收器中每个阵元所接收的声波信号的延迟时间可以改善接收指向性，并进而改善接收波形资料的质量。本报告的研究结果可以为声波测井、反射声波成像测井和井间地震勘探仪器研制和资料处理提供基础。
英文摘要	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. Frequency-wavenumber spectrum of linear phased array transmitters and the acoustic waves generated from the transmitters in the fluid-filled borehole are depicted. 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 enhance investigation resolution and signal-to-noise ratio in crosswell seismic survey and borehole acoustic reflection imaging. Small scaled model wells which are made of aluminium are measured by experiment. Longitudinal waves and reflected longitudinal waves from the outside model interface are observed. The method of phased scanning receiving is applied in signal processing of the experimental data. When the steered angle of the receiving main lobe is close to the first critical angle, the amplitude of the longitudinal waves is improved. It is proven that the quality and the receiving directivity of the experimental data can be obviously improved by adjusting the delay time of neighboring element of a receiver array and stacking the shifting signals of different elements. The results presented in the paper are contributed to the developing and data processing of acoustic well-logging, borehole acoustic reflection imaging and cross-well seismic survey.
语种	中文
公开日期	2011-05-07
页码	60
内容类型	学位论文
源URL	[http://159.226.59.140/handle/311008/1046]
专题	声学研究所_声学所博硕士学位论文_1981-2009博硕士学位论文
推荐引用方式 GB/T 7714	车小花. 相控扫描技术在声波测井的应用[D]. 中国科学院声学研究所. 中国科学院声学研究所. 2005.

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