径段 meaning in English

radial distance

The affects of slowness changes in serious hole collapse interval are not ignored
所以，在扩径段双发双收声系记录的时差数据有时需要进行扩径校正。
When interval of hole collapse does not change , the bigger change in hole diameter , the more poor the compensated ability
在沿井轴方向扩径段厚度一定的前提下，垂直于井轴方向的扩径量越大，双发双收声系的补偿效果越差。
But when interval of hole collapse is greater or less than the eigenvalue , the difference is small , and far more from the eigenvalue when interval of hole collapse is smaller
当沿井轴方向的扩径段厚度等于扩径厚度特征值时，补偿效果最差;而大于或者小于扩径厚度特征值时，补偿效果都会变好。