设计了一种利用周期性非轴对称孔槽来消除钻铤模式波的隔声体结构,并采用三维有限元法对其隔声效果进行了数值模拟。结果表明:所提出的隔声体的隔声效果与孔槽圆弧的半径、孔槽间隔及孔槽的数目等有关;适当选取刻槽方式时,1m长的隔声体对单极子源激发的钻铤波的衰减可达22dB,但对偶极子源激发的挠曲波的衰减效果不明显。
In order to eliminate the collar waves, a sound-isolated structure grooved on the drill collar is designed, and the 3-Dimensional finite element method has been applied to numerically investigate the insulation of the grooved structure. The results show that the sound insulation effects of the grooved structure are decided by the radius, interval and number of the grooves, and the proper grooved structure can effectively attenuate the collar mode-wave in logging while drilling environments. The attenuation of the isolator with length of 1 m can reach 22 dB, but the attenuation effect relating to the flexural waves is not obvious.