ND—S114型套管内割刀的研究与应用

针对油水井大修施工取换套管作业中使用ＮＤ—Ｊ１１４型机械式内割刀切割套管时操作工艺复杂、成功率低等缺点，研制开发了ＮＤ—Ｓ１１４型套管内割刀。这是一种利用水力学原理，从井下套管柱内部切割套管的专用工具，可在任意井深位置切割及打捞井下落鱼套管和套管附件，操作过程十分简单方便。切割刀具镶焊硬质合金，大大改善了刀具的切削性能，提高了切削速度和使用寿命，解决了以往高钢级套管（如Ｐ１１０套管）不易切削的难题。两年多以来３８井次的切割作业成功率都达到１００％，取出套管７万余ｍ。

Development and application of Model ND-S114 casing internal cutter

In the light of the shortcomings of the mechanical internal cutter for use in the operation of well workover, a hydraulic internal cutter, named NDS114 casing internal cutter, is developed. The cutter can be used for cutting or fishing downhole casing and accessories at arbitrary depth, and the operation is very easy. With hard metals inserted and welded, the cutter has good cutting ability and high cutting speed and long service life. Application of the cutter on 38 wells indicates that the cutter operates perfectly.