RU1795104C - Drilling device - Google Patents

Abstract

Usage: drilling wells with reverse circulation and correcting the deviation of the well from the vertical. SUMMARY OF THE INVENTION A device comprises a housing with rock cutting tools and a core pipe with a crown at the end. The core conduit communicates with the lower end of the nozzle offset from the axis of the housing. The upper end of the nozzle is coaxially fixed in the housing. When the device rotates, rock cutting tools form the bottom of the well. The core formed by the crown, when the washing fluid is circulated back, is transported through the core pipe, the nozzle and carried to the surface through the drill string. 1 C.p. f-ls, 2 ill.

Description

The invention relates to the drilling of wells, namely, drilling of wells with reverse circulation of drilling fluid and correction of deviations of production from the vertical.

A method and apparatus is known for correcting deviation of a drill hole from a vertical using a parallelogram diverter that acts on the drill body by means of rope tension from the winch. This method is complex, ineffective, and has not found practical distribution.

The known device has rock cutting tools containing a crown and a channel system for drilling fluid. However, this device is ineffective in operation; T.KV does not provide reverse circulation of drilling fluid.

An object of the invention is to increase the efficiency of well drilling through the use of reverse circulation.

This goal is achieved in that the device for drilling wells, comprising a housing with rock cutting tools, a core pipe located coaxially to the housing, a crown connected to the lower end of the core pipe ahead of the rock cutting tools and the adapter of the drill string, is equipped with a pipe, the upper end of which is connected to an adapter, and the lower end is offset relative to the axis of the housing, while the cavity of the core pipe communicates with the cavity of the pipe; core pipe is made curved.

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In FIG. 1 shows a device for drilling wells; Figure 2 is a core removal diagram.

In the drawings of FIG. 1 and 2, the following designations are adopted: 1 - case, 2 - rock cutting tool, 3 core pipe, 4 - crown, 5 - drill string adapter, 6 - pipe, 7 - core drill, 8 - core bore, 0pr - diameter core wire, Dn pipe diameter. dK is the core diameter, R is the radius of the circle inscribed in the bend of the core wire.

The device operates as follows. The crown 4, located coaxially to the housing 1 ahead of the rock-cutting tools 2 (Fig. 1), drills the central part of the face. The rest of the slab is treated with rock cutting tools 2, mounted on the housing 1 connected to the adapter of the drill string 5. The rock destroyed by the rock cutting tools 2 is removed with the flow of circulating flushing fluid through the pipe 6. The lower end of which is offset from the axis of the device and is open in side of the face to enter the rock.

The crown 4 when moving the face accommodates a rock core 7 in its internal cavity (see figure 2), which further,

passing through the core wire 3, it enters the pipe b and passing through the adapter 5 along the drill string is issued to the surface by a flow of circulating fluid.

The core wire 3, at the core entrance 7, is coaxial to the crown 4, and further, due to the fact that the lower end of the nozzle is offset from the axis of the device, it has an elbow 8. It rests against this elbow, a column of rock

core 7 undergoes bending and breaks, and then, cramped by the rock again entering the core wire, is discharged into pipe 6 having transportable dimensions and not blocking the suction channel. For

to ensure free movement of core 7 in curved core wire 3, the diameter of the core wire Dnp is increased with respect to the inner diameter of the drill bit (core diameter) bq.

In order to avoid blocking of the nozzle 6 with core pieces, the length of which would exceed the diameter of the nozzle Dn, bending of the core wire 3 should be limited. So, in the case of bending the core wire along the radius (see figure 2), the latter is determined by the condition:

R

GL

Un

8 (Dnp - die)

+

Dnp - dK

Claims (2)

SUMMARY OF THE INVENTION 1. A device for drilling wells, comprising a housing with rock cutting tools, a core pipe located coaxially with the housing, a crown connected to the lower end of the core pipe ahead of the rock cutting tools, and an adapter for the drill string, characterized in that, with purpose to increase operating efficiency through the use of reverse circulation, it is equipped with a nozzle, the upper end of which is connected to the adapter, and the lower end is offset relative to the axis of the housing, while the cavity of the core receiving pipe is in communication with the cavity of the nozzle. 2. The device according to claim 1, with the exception that the core pipe is made curved.