1. Usage
The hoisting wrenches are divided into external and internal types. They work together during operation and are mainly used for raising and lowering the drill string, lowering the casing, and removing and tightening the drill pipe threads.
2. Types are classified according to the size of the drill pipe they can grip: B-type hoisting wrench and casing hoisting wrench; according to the operation method: manual hoisting wrench and hydraulic large wrench. Currently, B-type hoisting wrench and hydraulic large wrench are widely used in domestic sites. The gripping size range of B-type hoisting wrench is φ88.9 - φ298.4mm. By replacing the wrench head, different-sized pipes can be lifted and lowered.
3. Classification of large wrenches
The large wrench is the main tool for connecting the drill string. Currently, the manual large wrenches used at the wellhead mainly include DB large wrench, SDD large wrench, B-type large wrench, and C-type large wrench. DB large wrench: The main working size is 3-½" to 8-¼", and the enlarged wrench head can reach 17". Torque range: 3-½" to 8-¼": 65000 ft-lb, 8" to 17": 40000 ft-lb. SDD large wrench: The main working size is 4" to 8-½", and the enlarged wrench head can reach 17". B-type large wrench: It is mainly used for removing and tightening the casing, with a size range of 3-½" to 13-3/8", and the extended wrench head can be up to 25-½". C-type large wrench: This is a portable large wrench, with a size range of 2-3/8" to 10-¾", and the maximum torque is 35000 ft-lb.
4. Maintenance and usage
1) Keep the hoisting rod flexible to facilitate leveling;
2) The valve is flexible, safe and reliable, and has sufficient elasticity;
3) After assembly of each wrench head, the hinge is flexible and the safety pin is complete;
4) When the teeth are worn down to 1/4 of the original height, a new tooth plate should be replaced;
5) Regularly lubricate the moving parts for maintenance;
6) The hoisting wrench suspension rope should be as high as possible;
5. Notes ⑴ Select an appropriate 5# jaw to ensure that the clamping size matches the size of the drill pipe. ⑵ The swivel clamp should be placed on the drill pipe joint. The upper and lower jaws should be 30-50mm away from the sealing surface of the joint. The inner and outer jaws should form an angle between 45° and 90°. When tightening, the outer jaw should be on top and the inner jaw should be below. When loosening, the outer jaw should be below and the inner jaw should be above. ⑶ When replacing the jaw teeth, do not aim at the wellhead and be careful not to injure your fingers or have the jaw teeth break off and injure someone. ⑷ When applying the clamp, do not place your fingers between the 3# long jaw and the 4# short jaw to prevent squeezing your fingers.