Slipper spear is composed of upper joint, spear rod, slide block and blocking key.
When the spear rod and slider enter the fish cavity, the slider slides down by self weight, the slide block and the inclined plane produce relative displacement, and the distance between the slider and the center line of the spear increases, and the size of the fishing is gradually increased until contact with the inner wall of the fish cavity. The upward radial movement of the drill tools and the upward movement of the spear rod force the slider to bite the inner wall of the falling object and grasp the falling object.
The slider spear is an internal fishing tool, it can fish drilling rod, oil pipe, sleeve milling pipe, liner, packer, distributor, and other falling objects with inner holes, and can also reverse the falling objects.
1. Considering the water hole of excretory liquid, preventing the release of the fluid from the oil drilling tools
in the drill and causing the drop of the liquid level in the well or the pollution of the environment, the fishing tool with water hole or the joint with the water hole should be taken.
2. When fishing for large diameter falling objects, it should be considered whether the drilling tools above the spear should be entered into the fish cavity, otherwise the upper part of the spear should install the limitation devices to limit the depth.
3. The problem of catching a spear into the well should be considered when fishing. If the spear is inserted outside the fish cavity, it is easy to cause the deformation of the head and the falling of slider, and increase the difficulty of the work in the next step.
4. If a giant torque is needed, the thread rotation of the spear, joint, drill tool and other tools in the well should be taken into consideration, so as to prevent the accidents when fishing and reversing and the construction progress.
5. When the top-fish is covered by sand and has a high sand column, it is not suitable to use the slider and spear to catch in order to prevent the sand sinking and sticking.
If you use the slider and spear to reverse, the drill tools should be lifted in advance, so that the spear and the fish cavity could be tightened in case of slipping.