The? taper tap is a special fishing tool making thread on the inside wall of tube dropped objects such as drill pipe and oil tube, and the Die Collar is a special external fishing tool which is engaged on the outside wall of tubing objects such as oil tubing and drill pipe.
Lift nipple is designed to lift up or put down and screw on or off drill sting. It has two types. One with thread connector on two ends is named as type A, and another only with thread connector on bottom end is named as type B.
Liner hanger is a special tool to hang and cement liners. A liner hanger is made up of principle body, running tool and other tools etc for special purpose. Liner hangers are classified as two kinds of mechanical type which completes to hang liner by operating drill string and hydraulic type which completes to hang liner by hydraulic pressure. There are small step type, hydraulic type, guide track type, J-groove type as well as cuniform block type etc used in oil field, and among them, small step type, hydraulic and guide track type liner hanger are widely used.
