SU1649084A1 - Plugging-back tool - Google Patents

Abstract

The invention relates to a drilling technique. The purpose of the invention is to improve the quality of plugging and increase productivity. The device contains a container (K) 1 for the cement mixture. In the upper part of K 1 there is a transverse partition 2 with a central opening 3, a hollow cylinder (PC) 6 rigidly connected with it with a cover and a valve. The valve consists of two interconnected parts - rod (Ø) 4 and piston 5. PC 6 is installed above the partition 2 with a gap and through channel 7 is hydraulically connected to the annular space. In the opening 3, an W 4 is placed, and a piston 5 is located in the PC 6. In the lower part of K 1 there is an end cap consisting of two plugs 9 and 10. The stopper 9 is made below with a conical recess. The plug 10 has a counter side conical surface and is installed in a recess with the possibility of forming a hermetic cavity. A drill pipe device is lowered into the well. The stopper 10 due to the hydrostatic pressure has a spreading effect on the stopper 9, pressing it against the walls of K 1. A liquid is pumped into the column. The piston 5 is displaced upward into the PC 6 and pulls Ø 4 out of the hole 3. The liquid enters K 1 and forces the nei into the plug and the mixture. In this case, the column is raised by the length K 1. The plug 10 is pressed into the plug 9, expanding it to the walls of the well, 2 sludge. J

Description

The invention relates to a drilling technique and is intended to plug-in the absorption zones of the washing liquid or to fix unstable intervals during the drilling of wells in one descent-ascent of the backfill tool.

The purpose of the invention is to improve the quality of plugging and increase productivity.

Figure 1 shows the cement plug d, General view; figure 2 - the same, in the working position.

The backing projectile includes a container 1 for a grouting mixture, in the upper part of which a transverse partition 2 with a central opening 3 is installed. In opening 3 there is a valve stem 4 connected to the piston 5 of the valve, which is located in a hollow cylinder 6 with a lid mounted above the partition 2 with a gap and rigidly connected with the container 1. The cylinder 6 through the channel 7 is hydraulically connected with the annular space. In the bottom of the container there is an inner circle.

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The bead shoulder 8, and below it, the end cap, is made of two plugs 9 and 10. The stopper 9 has a conical recess below, and the stopper 10 is made with a counter side conical surface and is installed in the recess with the possibility of forming a hermetic cavity. The stopper 10 is made of a harder material than the stopper 9.

The breakdown unit is part of the projectile in the event that the tamper material is used in a dry form, and the quick-hardening mixture that is transported in a liquid state is not ready. It consists of a spring-loaded piston 11, worn on a pipe 12, having radial holes 13 and articulated with a conical sleeve 14 with longitudinal conical ridges corresponding to planes of dies 15 rigidly connected with plate springs 16 with a landing shoulder 17. At the bottom of the conical sleeve 14 there is a longitudinal groove (not shown in the drawings) in which the trowel 18 is placed in the form of an elastic ring. The end of the sleeve 14 has a threaded connection with the breakout member 19. When the cement shells are lowered to a considerable depth, a technological washer 20 is installed between the back surface of the upper part of the plug 9 and the collar 8.

The procedure for working with the projectile is as follows.

The plugs 9 and 10 come together with the provision of a suction phenomenon achieved by bleeding off air. The assembled plug together with the washer 20 is pressed into the lower part of the container 1 with a force of several (for example, 3 times) exceeding the weight of the contents of the latter. It is also permissible to use glue.

When the septum 2 is removed, the cavity of the container 1 is filled with a ready-made fast-hardening mixture in a liquid state or with a dry preformed (packaged) grouting material. In the case of a dry cement material, a stand-off unit is placed on top of it, and then the partition 2, the piston 5 and part of the container are installed, including cylinder 6, which is attached to the rest of the container, for example, by means of a threaded joint.

A projectile thus assembled on a drill string having a check valve (not shown in FIG.) Is lowered into the well. During the descent, the tube 10 due to the hydrostatic pressure of the liquid column in the well has an arching effect on the tube 9, pressing it against the wall of the container 1, since the washer 20 prevents it from moving upwards, thus achieving the necessary tightness. From the penetration of liquid in the upper part of the container 1 protects the rod 4.

When a given depth is reached, fluid is pumped into the drill string. When this piston 5 is displaced up, displaced

0, a certain volume of fluid above it enters the annular cavity through channel 7, and the stem 4 associated with it releases an opening 3 through which the fluid in the drill string enters the

5 container 1 and fills it. When an overpressure pump creates pressure, the contents of container 1, including the plug, are moved to the wellbore. The drill string while raising on

0 container size 1.

The hydrostatic pressure of the fluid in the well presses (the plug 10 into the plug 9, which, radically expands, overlaps the wellbore. Simultaneously with the cement material, the standoff moves to the stop of its landing collar 17 into the circular shoulder 8. Piston 11, compressing the spring (see FIG. 2) will open the holes 13 for

0 movement of the fluid injected from the surface, and the dies 15, being in the upper position relative to the conical bushing-. freely pass through the circular collar 8 as far as it will go, the landing collar volume 17 into the collet 8.

At the beginning of the drilling of packaged cement material, the conical sleeve 14 moves upward and wedges the plates 15 in the container 1, thereby achieving fixation of the tooling unit in the container and transfer of torque from the drill string to the tooling unit. When the projectile is rotated, the mixture with the trowel 18 is pressed and

5 is rubbed into the cracks of the borehole walls.

Claims (1)

The invention has a backing projectile including a container for a cement mix with an end cap at the bottom and a valve at the top, characterized in that, in order to improve the quality of plugging and increase labor productivity, it is provided with a transverse partition with a central opening installed at the top. parts of the container, and a hollow cylinder with a lid located in the latter above the transverse partition with a gap rigidly connected with it and having a hydraulic connection with the annular space, the valve is made in the form of a piston installed in the cylinder and a stem connected with it, placed in the central opening of the transverse partition, and the end cap is made of two plugs. one of which has a conical recess below, and the other is installed in the latter with the possibility of forming a hermetic cavity and has a counter lateral conical surface. FIG ( h 2 Fig2