SU1268711A1 - Apparatus for drilling holes under protection of casing - Google Patents

Abstract

The invention relates to the mining industry and is intended for drilling shallow wells with coring under the protection of the casing. In order to increase the efficiency of work by impacting the casing, the rock-breaking tool 4 is made in the form of a gear crown with a shank 6. The shank 6 is located in the casing pipe 5 s (L 1LL / u L /// /// /// xx / / y / // y /// /// / l Fig.}

Description

possibility of limited axial re-stage. For this, the shank 6 has a protrusion 7, and a protrusion 8 is made at the lower end of the casing 5. In the case where the casing string hangs in the well. the serrated projections of the wedge-shaped form of one surface relative to the serrated projections of the other surface create a shock effect on the casing and cause it to descend into the well. 3 il.

The invention relates to the mining industry, in particular to devices for rotary drilling of shallow wells with coring under the protection of the casing.

The purpose of the invention is to increase the working efficiency by means of the impacting of the casing.

FIG. 1 shows the proposed device, a longitudinal section; in fig. 2 shows section A-A in FIG. one; in fig. 3 is a view B in FIG. 1.

A device for drilling squalves under the protection of a casing string consists of a drill rod 1, a core receiver tube 2, which is connected with rock cutting tool 4 having a shank 6 located in the casing pipe 5 with a slotted joint 3. The rock-breaking tool 4 is made in the form of a gear crown. The shank 6 is located in the casing with the possibility of limited axial movement, and the movement stops are made in the area of the protrusion 7 on the shank and the protrusion 8 on the lower end of the casing. The device has a percussion mechanism, the interacting toothed surfaces 9 and 10 of which are located respectively on the protrusions 7 and 8.

The proposed device works

in the following way. I

The torque from the drive of the drilling rig (not shown) is transmitted to the drilling rig 1, the core-borne pipe 2 and through the spline joint 3 to the rock-breaking tool 4 that forms the borehole. As the well deepens, the rock enters the internal cavity of the core-receiver pipe 2, which, when filled, is extracted to the surface and cleaned, and then set back to its previous position. In the absence of resistance, the promotion of the casing composed of the casing 5j can occur under the action of its own weight. Otherwise, the casing is immersed forcibly, due to the impact of two gear surfaces 9 and 10. This occurs when the casing is suspended in the well, and the rock-breaking tool is in the lowest position relative to the end of the casing 5, In this position, the serrated wedge-shaped Surface shapes 9 (FIG. 2) move along similar protrusions of surface 10, creating a shock effect on the casing, causing it to sink into the well.

The magnitude of the free stroke of the rock-breaking tool 4 relative to the casing string is determined by the maximum height of the stable non-fixed interval of the borehole.

Claims (1)

Invention Formula A device for drilling wells under the protection of the casing string includes rock cutting tool, core tube, drilling rig, casing tube and percussion mechanism in the form of interacting gear surfaces, characterized in that, in order to increase the efficiency of work by percussion immersion of the casing string, the rock bending tool is made crown with shank placed in the casing with the possibility of limited axial movement, and axial movement limiters are made in the form the protrusions on the shank and on the casing pipe 14, while the core-receiving pipe is connected with the gear crown with the possibility of axial movement and joint rotation, and the gear surfaces of the percussion mechanism are located on the projections of the limiters for the axial movement of the shank. Fig.Z