SU145495A1 - Overshot for removing the inner tubing - Google Patents

Description

Overshots are known for extracting an inner core tube during core drilling.

A distinctive feature of the described overshot is that in its lower part there is a cylinder on the rod, in which the claws are fixed. This embodiment of the overshoot accelerates the process of extracting the inner core tube to the surface.

FIG. 1 shows a section overshot; in fig. 2 — A double column tube with a removable inner tube.

The overhead is a body /, inside of which is located a rod 2 with a mesh at the end of a cylinder 3 with grippers 4. The rod has a free stroke inside the body. The overhang is lowered inside the drill pipe on a cable, the end of which is secured in the cable lock 5.

The double column tube (see Fig. 2) consists of an outer core tube 6, an inner extraction tube 7, an adapter 8 and a small diamond multi-layer crown 9. At the upper end of the inner tube 7, an adapter with a pin ending fungus 10 is screwed to extract the tube 7 with the help of overshot. To prevent the pipe / in the axial direction from mixing, there are two stops 11, rotated on the axis 12 under the influence of springs 13. In the lower part of the pipe 7, a groove is cut into the length of the crown, which includes a retainer 14, which prevents the pipe from rotating during the core casting. In the upper part of the pipe 7, holes are drilled to allow the passage of the washing liquid and the spike. Finely ground porcelain is recommended for diamond drilling.

Removing the inner tube 7 (see Fig. 2) is carried out as follows.

No. 145495-2. When the overshot is lowered into the well, the stops // are moved apart by the body / overshot, the rod 2 is lowered, and the grippers 4 cling to the fungus / 0. When an overshot is lifted, the body of its first time remains in place (due to the free stroke of the rod), which ensures that the upper end of the pipe 7 rises above the stops // of the double core pipe.

The Institute AzNII notes the simplicity of the construction of the overshot and recommends it for industrial verification.

Subject invention

Overshot for removing the inner core tube, characterized in that, in order to accelerate the process of extracting this tube to the surface, in its lower part there is a cylinder on the rod, in which the clamps are fixed.