Mechanical Internal Cutter

The ND-J type internal cutter is a down-hole cutting tool designed to cut casings, tubings and drill pipes mechanically. It owns some advantages of simple structure, reliable performance, high cutting efficiency. In order not to cut casings, tubing couplings, before run in hole, the cutter shall be kept away from collar position, if condition is allowed, it can be used with collar finder. It can be used with releasing spear, the cut off pipe strings can be either pulled out of hole with cutter or caught out by fishing tools alone.

Working principle

When internal cutter is run in estimated depth down-hole, right to rotate mandrel of cutter for three circles so that sliding sleeve separates off sliding sheet. At the time,the friction block closes against pipe wall due to the function of spring, the parts on centralizing body and slips don't rotate in pace with mandrel but move up due to engagement of sliding sleeve and sliding sheet, also at the time, down the drill string the slip diameter is expanded due to sloping function of slip cone-shaped body, the slip bites the inner wall of pipe, then cutter is anchor bolted on pipe wall. In this case, lift up mandrel about 10mm, then lower and rotate mandrel slowly, so that three cutters radial open up depending on cutter push block, cutting operation can be done. The cutting operation is not finished until mandrel press against end Face of thrust ring. When lift up mandrel, under double functions of blade spring and its self-weight, three cutters separate off inclined Face and take back blade edges, additionally, sliding sleeve and slip sheet come back to original engagement depending on slip sheet spring and structure of tooth threads. Meanwhile, the slip cone moves up in pace with mandrel so that slip looses cutting tools bolted on pipe wall and continues to move up until upper cone-shaped face of guide nut with draw against tooth face of locking ring before pull out of tools cut..

When ordering please specify:

•     Pipe size and weight to be cut.

•     Top connection

Specifications - Mechanical Internal Cutter