packoff shoe 封隔套管鞋

annular packoff 环形封隔

cable packoff 电缆头密封

packoff sub 密封短管

split packoff 拼合式封隔装置

packoff adapter 密封接头

packoff bushing 密封补心

wireline packoff 电缆操作的封隔器

packoff element 封隔元件

packoff preventers 封隔防护设备