【摘要】 本文是直接针对声法石油测井的需要提出的,假定体系为准弹性均质固体中的流体柱,测井声系用局部表面振动的中心圆柱模拟。采用二维快速Fourier变换(FFT)算法,对不同频率的声源在各种岩性下的声场进行了计算,得到了一系列记录点的声压波形曲线。这些曲线清楚地表明有四种波群存在,计算了它们的速度,误差低于4％;同时也给出了衰减特性曲线。 计算结果表明,物理模型是可取的,计算方法与程序可靠,为开展全信息测井研究提供了理论依据和有效手段。更多还原

【Abstract】 This article is presented out of to the necessity of the acoustic logging of petroleum wells.The system is assumed to be a fluid cylinder surrounded by a uniform quasi elastic solid medium and the acoustic logging tool is simulated by a central rod with local vibrating surface.The two dimension fast Fourier Transform(FFT)algorithm is adopted.Sound fields in rocks of different properties using different source frequencies are calculated and the sound pressure waveform curves on a series of recording points are obtained.These curves clearly indicate the existence of four kinds of wave groups.The error of their calculated velocities is less than 4%.The characterestic attenuation curve is also given.The results of calculation show that the physical model is acceptable and the method of calculation and the computing program are reliable and thus provide a theoretical basis and an elegant method for holographic study of oil well logging.更多还原