SU859609A1 - Automatic depth apparatus for closing borehole shaft - Google Patents

Description

(54) AUTOMATIC DEPTH DEVICE FOR BREAKING THE BOTTOM SHORT The invention relates to oil production, in particular, to structures of deep-seated devices that automatically shut down the wellbore immediately after the cessation of fluid extraction from the well, both in the flow and in the mechanized method of its production. A device for blocking flow wells is known, providing automatic shut-off of the well bore with an increase in flow rate above the optimum and allowing to perform work on repairing the well’s downhole equipment without plugging it 1. However, to put the well equipped with the above device into operation, it is necessary to create an pressure or on the scraper wire to lower the weight into the well, which puts the upper balancing valve in the “Open” position, i.e. the device is semi-automatic, since it does not automatically open the valve of the device for the passage of the produced fluid during the start-up of the well. The closest to the proposed technical entity is a depth device for blocking the wellbore before underground repair, performed as a cylindrical body with radial holes mounted on the packer, in which a rigidly connected nozzle, movable cup, mounted between the body and the nozzle, is concentrically placed. and piston. This device is fully automatic, as it provides the wellbore overlap when the liquid is withdrawn from it and connects the sub-packer space with the nadpakner one when the well is put into operation without performing any additional operations 2. However, during the extraction of fluid from the well, the upper spring Constantly in the most loaded state and subjected to cyclic alternating loads. This leads to premature spring breakage and, consequently, to a decrease in the service life of the device as a whole.

The operation of the device is associated with significant axial movements of the movable sleeve (piston). The magnitude of the axial displacement is directly proportional to the size of the holes through which the produced fluid from the sub-packer space enters the supra-packer space. Increased well production requires an increase in the size of these holes, which leads to an increase in the axial displacement of the glass (piston).

In addition, during the extraction of products consisting of a three-phase mixture, oil, gas and water, due to the constantly changing phase ratio of the mixture, the movable cup (piston) is constantly shaved axially, since during the extraction of the liquid it is held in spring condition washed by its upstream of produced fluid. As a result, the wear of the mating surfaces of these elements increases, resulting in gaps and impaired tightness of the device shut-off devices, i.e., when the device is triggered, the liquid in the sub-paccine space does not cut off from the liquid in the above-packer space. The device as a whole ceases to comply with the requirements imposed on non-requirements. Thus, despite the high reliability of operation, as a result of a decrease in the functional reliability, the operational reliability of the device as a whole turns out to be very low.

The purpose of the invention is to improve the operational reliability of the device by eliminating cyclic alternating loads, significant axial movements and vibration of the movable sleeve.

This goal is achieved by the fact that the device is equipped with working and control spring-loaded pistons and lower and upper spools with axial channels, the working piston being installed in the lower part of the nozzle and rigidly connected with the lower spool and the piston that is rigidly connected with the movable glass and a spring loaded control piston is installed in the upper part of the nozzle and rigidly connected with the upper spool, the upper and lower spools forming a chamber in communication with the supra-packer and sub-packer spaces, and under Vision glass is made with inclined slots, in which clamps of its extreme upper and lower positions are installed.

FIG. 1 shows a device for extracting fluid from a well to the surface, a longitudinal section; in fig. 2 is a view A of FIG. one; in fig. 3 - device with a blocked borehole; lengthwise cut; FIG. 4 is a view B of FIG. 3

Automatic depth device for blocking the wellbore contains

housing 1 installed in the well on the packer2. A nozzle 3 rigidly connected to it is placed inside the housing, and a movable sleeve 4 is placed in the annular space between the housing 1 and nozzle 3. Holes 5 are made in case 1, holes 6 are made in moveable glass 4, and holes 7 are also made in nozzle 3. fluids from the well, when the device communicates the sub-packer space with the overpack, the holes 6, 5 and 7 coincide with each other. In the lower part, the movable cup 4 is rigidly connected to the pressure gauge 8, which is pressured by the environment of the subpacker space. The lower part of the nozzle 3 is made in the form of a chamber I, where the lower spool 9 and the working piston 10 are located, both of which are rigidly interconnected with each other, as well as with the movable cup 4 and the piston 8. The upper part of the nozzle 3 is made in the form of a sealed chamber II with the channel in which the control piston 11 is placed, spring-loaded 12. A control medium of the subpacker space interacts with the control piston 11. The control piston 11 is rigidly connected to the upper spool 13, which also, like the lower spool 9, is placed, is in chamber I of nozzle 3. In the lower 9 and upper m 13 of the spool axial channels 14 are made. The cavity of the chamber is connected by a channel 15 s. overpacker

0 space, and the channel. 16 m - with subpacker. In the walls of the movable cup 4 there are inclined grooves 17, in which clamps 18 of the extreme upper and lower positions of the cup 4 are mounted fixed on the device body 1.

The device works as follows. After the pump stops, the pressure in the space above the packer 2 will increase due to an increase in the fluid level in the well. As a result, the control piston 11 starts to descend, compressing the spring 12. At the same time, the upper spool 13 rigidly connected with the control piston P moves down and opens the opening of the channel 16 connecting the chamber cavity with the sub-packer space. As a result, the pressure in cavity III and in the axial channels 14 connected with it through the upper 13 and lower 9 spools of cavities I and IV increases and becomes equal to

° subpacker pressure. Due to the difference in the areas of the working piston 10 and the piston 8, the working piston 10 together with the lower valve 9 moves down and opens the opening of the channel 15 connecting the cavity of the chamber I with the supra-packer space. Due to the fact that the working piston 10 is rigidly connected with the piston 8 and the movable cup 4, the latter receive

axial downward movement with simultaneous radial rotation. The body of the movable cup 4 closes the holes 5 in the housing 1 and 7 in the pipe 3. This ensures that the supply of liquid from the sub-packer space to the nadpacker space is stopped. The wellbore is blocked. When the wellbore (Fig. 3) is blocked, the upper spool 13 closes the opening of the channel 15 connecting the cavity of the chamber I with the supra-packer space. The opening of the channel 16 connecting the cavity of the chamber I with the subpacker space is open. The pressure in the cavity of the chamber is equal to the pressure in the subpacker space.

After the pump is lowered into the well and its commissioning, the pressure in the overpack space decreases due to a decrease in the fluid level in the well.

The control piston 11, due to a decrease in the pressure of the fluid in the overpack space, under the action of the spring 12 moves upwardly together with the upper spool 13. The upper spool 13 opens the opening of the channel 15 connecting the cavity of the chamber I with the above-packer space, linking the cavity of chamber I with the sub-packer space. The pressure in the chamber becomes equal to the above-packer pressure. Due to the decrease in pressure on the working piston 10 with respect to the pressure on the piston 8, the latter, together with the working piston 10, the lower spool 9 and the movable cup 4, moves upwards. The movement continues until the lower spool 9 covers the aperture of the channel 15 connecting the cavity of the chamber with the above-packer space. As a result of the axial movement of the movable cup 4 upwards and its simultaneous rotation around the axis (carried out as a result of the interaction of the working surfaces of the inclined grooves 17 of the movable cup 4 with the latches 18 installed directly in the device case 1), the holes 5, 6 and 7 are aligned, the sub-packer and overpacker space. Well is ready for operation.

Saving when using the proposed device reduces to

the number of underground repairs of the well (the number of lifts and installations of the device is reduced, together with this, the damping and subsequent well development after repair), as well as an increase in the current oil production, as the well overhaul period increases. The economic effect on one well with a flow rate of 40 tons / day with a well depth of 1500 m will be about 2 thousand rubles per year. In general, the industry will save about 5-10 million rubles a year.

Claims (2)

1. USSR author's certificate number 432278, cl. E 21 B 43/12, 1974. 2. USSR author's certificate  No. 184207, cl. E 21 V 33/12, 1966 (prototype).