声波测井网络理论Ⅰ:声源信号的产生方法和数值模拟

Network Theory of Sonic Logging I:Methods for Generating Sonic Source Signals and Their Numerical Simulations.

利用薄球壳压电换能器的等效电路可以解析地确定在薄球壳压电换能器被电激励信号激发过程中 ,周围耦合介质对它的作用力和它的瞬态响应。给出了用驱动电压信号激励换能器使其辐射出马鞍组特殊测井需要的声源信号。由于薄球壳换能器在所有的方向上均匀地向外辐射声波信号 ,因此在声波测井的正演研究和数值模拟中 。

By utilizing the equivalent circuit of thin spherical shell transducer, both the effective force of surrounding coupling fluid on a thin spherical shell transducer during excitation by a driving-voltage signal and its transient response can be determined by developing an equivalent circuit. The transducer acts like an electrical-acouistic filter during logging.The properties of both driving-voltage signal and transducer determine that of the radiated acoustic signal. For a transducer, by choosing suitable driving-voltage signal, we can make the transducer radiate the desired acoustic signal to satisfy different logging requirements. Because the thin spherical shell transducer polarized in radial direction radiates acoustic signals evenly in all directions, it can be equivalent to an omnidirectional point source used in the numerical value simulation and forward research of the acoustic logging.