脉冲超声波测井仪

一、引言超声测井是一种新的地震測井法,它是利用超声波来研究小間隔內（1-2米）鈷井剖面岩层的物理机械性貭。近年来,由于石油探測事业发展的需要,这种方法在地球物理勘探和地球物理测井中受到了广泛的注意。根据超声測井的試驗和应用的結果看来,这种方法可以簡捷、經济、精确、詳細地測定出岩石的物理机械性貭（纵波和横波的波速,波的吸收系数等等）及其随深度的变化。

A SUPERSONIC IMPULSE WELL-LOGGING INSTRUMENT

Well-logging by supersonic waves is a quick and accurate method for studying elastic properties of the rocks pierced by a bore-hole. This paper describes the construction of a supersonic impulse well-logging instrument built in our laboratory, chiefly after the scheme used by the Institute of Physics of the Earth of the Academy of Sciences, USSR. But pulse amplitude, repetition rate, circuit constants etc. are designed to suit the types of electron tubes available and the dimensions of the barium titanate transducers that can be prepared with the facilities in our laboratory. The principles of choice of the dimensions of the component parts, the transducers etc. are presented. One emitter and two detectors of supersonic impulses, together with their respective pro-amplifiers are built into the probe. On the other end of the cable there are the main oscillator, the four frequency divisors, the impulse generator which supplies energy to the supersonic emitter, and also the intermediate amplifier, the cathode-ray oscillograph, the time mark generator, and time delay circuits. Supersonic waves picked up by the two detectors and the time marks are displayed on the screen of the cathode-ray tube, and photographed together. From the difference between the time of arrival of the longitudinal refracted waves（ppp） and that between the transversal refracted waves（psp）, and the distance between the two detectors, the respective wave velocities Vp and Vs can be calculated. From these, the Poisson's ratio and Young's modulus of the rock can be deduced. Both indoor experiments and well-test data show that the instrument can work satisfactorily. Accuracy of results are discussed; future improvements are also suggested.