偶极子横波测井方法的实验研究

A Laboratory Study on the Dipole Shear Wave Logging

刘子华等：偶极子横波测并方法的实验研究，测井技术，１９９６（３）２０，１５７～１６１。最近，研制出两种新的偶极子声源，一种是片状的，另一种是圆管状的。对两种声源的性能进行了实验比较，发现室内混凝土模型井中观测到的偶极子声波（弯曲波）波形的首波相速度近似等于混凝土横波速度，其视频率约为单极子声波频率的一半，即１０ｋＨＺ左右。实验还表明，在短源距时测定弯曲波参数较为方便。

Recently,two new dipole acoustic sources-one is made of bimorphs and theother cylindrical piezocrystals-have been developed.Their properties are compared experimentally in detail' The experimental results show that the phase velocity of the first arrival of the dipole acoustic waves (fie-cure waves)in model well,which is made of steel pipe covered in concrete,is approximate to the shear wave velocity of cement,and that its apparent frequency is as half as that of monopole headwave (about 10kHz).It is also found that it is easier to measure the fie-cure wavevelocity under the condition of short spacing.