超声匹配层对油井超声透射系数的影响

Influence of matching layer on transmission coefficient of ultrasonic in oil wells

文章提出了一种采用匹配层增大超声在油井中透射系数的方法,并利用声压及振动速度在介质分界处连续性的条件得到了声波在油井中的透射系数。透射系数的大小与匹配层、井液、套管、水泥层及岩层等的物理参数有关。根据数值计算得出:当井液密度、水泥层密度、匹配层半径增大时,透射系数增大;当匹配层的声速、密度增大时,透射系数降低。这说明能运用匹配层改变超声在油井中的透射系数。

In this paper,a method is described for increasing the transmission coefficient of ultrasonic in oil well by using a matching layer.The transmission coefficient is obtained according to the wave propagation and the continuous boundary condition on the sound pressure and the vibration velocity,when the drum matching layer is put on the ultrasonic transducer in oil well.The performance parameter of the matching layer and the well liquid and the casing pipe and the cement layer and the rock have an effect on the transmission coefficient.It is reported that the transmission coefficient will increase as the mass density of the well liquid and the cement layer and the radius of the matching layer increase,and that the transmission coefficient will decrease as the mass density and the velocity of sound of the matching layer increase.This shows that the transmission coefficient of ultrasonic in oil well can be changed by using the matching layer.