RU2268994C2 - Well bottom zone cleaning device - Google Patents

Abstract

FIELD: oil industry, particularly devices for hydrodynamic well treatment.

SUBSTANCE: device comprises power source and energy converter linked to the power source and made as multiplicatory pulse generator. The energy converter is made as pre-cavitator and main cavitator. One of the cavitators is formed as cylindrical bush. Outer side bush surface has annular recesses so that annular Venturi pipes are created between inner casing pipe surface and cylindrical bush surface. The main cavitator has body in which guiding means with tail, as well as bush with conical orifice, disk spring assembly and disk spring fixing means are arranged. Annular cap is put on guiding means tail. The disk spring fixing means is formed so that the cap is spring-loaded against the bush having conical orifice. Through channels are defined by the guiding means and the body. The guiding means is secured in the body by cylindrical bush of pre-cavitator and by bush having conical orifice. The bush and spring-loaded annular cap may form conical annular channel on outer side and adjacent end surfaces of conical annular channel. The channel is adapted for working liquid circulation from power source so that annular jet is created and directed to inner surface of casing pipe and working liquid enters into annular grooves of pre-cavitator bush.

EFFECT: increased well productivity due to improved well bottom zone treatment.

8 cl, 2 dwg

Description

The invention relates to the oil industry, in particular, to devices for hydrodynamic influence on the bottom-hole zone with the aim of intensifying the processes of restoration of the operational characteristics of the wells, namely, to increase oil recovery, cleaning the bottom-hole zone of sediment, clogging rock particles and drilling mud residues, as well as those deposited in porous sediment of salts and asphaltene-resin-paraffin deposits.

So, it is known a device for influencing the bottom-hole zone of a well, which is an electrolytic generator of hydrodynamic pulses, including an electrolyzer. The cell is made in the form of electrodes placed coaxially and separated by a current-insulating diaphragm, and contains an explosive chamber with an ignition initiator (AS No. 977712).

Significant disadvantages of the known electrolytic generator are complexity, low maintainability and design imperfection, which leads to a significant complication of the technology of its application and limited operational capabilities.

Known and other designs of devices for influencing the bottom-hole zone are L.Kh. Ibragimov. "Theory and practice of using flooded high-speed turbulent jets and boiling adiabatic flows of influence on the bottom-hole zones of wells", M .: 1997, p. 46-74, which are structurally close to the claimed invention, but the closest to this invention is a device for cleaning bottom-hole zone of the well (RU 2138617), which contains an energy source and an energy converter connected to it in the form of a multiplier pulse generator and a molecular wave cavitator coupled to it.

The multiplier generator consists of a hollow body and a tubular rod located in it with a piston and valve, which are mounted on the rod with the possibility of axial movement. The housing is made with a bottom, which has a central hole and two peripheral ones, in which are located - in one throttle, and in the other - check valve.

Radial channels are made in the side wall of the central part of the housing.

The rod is installed in the central hole of the bottom of the housing and has an end cap on the opposite side, which overlaps its internal channel and forms a discharge chamber with the valve body and end face connected to the energy source and to the internal channel of the rod.

The discharge chamber is connected to the channel using radial holes in its side wall, located with the possibility of their overlapping by the valve wall during its working movement. The valve using a spring placed in the void formed between the walls of the valve and the housing and connected to the discharge chamber, pressed against the end face of the piston with the formation in the contact zone of the void, connected using an annular internal groove and radial holes in the piston wall to the radial channels of the side wall of the housing .

The molecular wave cavitator is made in the form of a glass, which is attached with an open end to the housing of the pulse generator along the periphery of its bottom. Radial channels with a connecting peripheral annular groove are made in the side wall of the cup, and the inner emptiness of the cup is connected by a throttle and a check valve to the pulse generator animation chamber formed between the piston end and the bottom of its body.

As can be seen from the previously described, the pulse generator has a complex and non-repairable design, in addition, significant energy consumption is required for its operation.

A significant drawback of this device is the low intensity of the cavitation field, since the cavitator design does not allow maximum use of the flow energy and does not ensure its uniform redistribution throughout the volume in the casing in the device zone. Therefore, the processing process is not efficient enough.

The basis of the invention is the task of increasing the productivity of, for example, oil wells due to better cleaning of the bottom-hole zone of the well while reducing energy consumption, by increasing the intensity of the cavitation field, intensifying the process of cleaning the bottom-hole zone.

This problem is solved by improving the known device, which has an energy source and an energy converter connected to it in the form of a multiplicative pulse generator and a molecular wave cavitator coupled to it, in accordance with the invention, the converter is made in the form of upstream and main cavitators.

The main cavitator has a housing that is connected on one side to the upstream cavitator and the second with a cylindrical sleeve; a guide with a shank is placed in the housing, on which an annular plug, a disk spring unit and means for fixing them are mounted so that the plug is spring-loaded to the hub.

The upstream cavitator is made in the form of a cylindrical sleeve and has annular recesses on the outer side surface. Annular recesses form annular venturi with the inner surface of the casing. To connect the upstream cavitator to the tubing, it has an adapter.

The above set of essential features allows us to achieve the previously indicated technical result by creating a cavitation field in the bottomhole formation zone by expiring a flooded high-speed pulsating flat turbulent ring jet and forming a secondary cavitation zone with the generation of molecular-wave vibrations.

The claimed combination of essential features is new, industrially applicable due to the absence of one of them, the technical result cannot be achieved.

For the concept of the essence of the invention, we present a list of figures depicting the inventive device:

Figure 1 is a longitudinal section of a device for cleaning the bottom-hole zone of a borehole;

figure 2 - shows a section aa of the device.

The main cavitator has a housing 1, a guide 2, a sleeve 3 with a conical hole and an annular plug 4, spring-loaded with cup springs 5.

The upstream cavitator is made in the form of a cylindrical sleeve 6, which has an adapter 7 for connecting to the tubing. The sleeve 3 with a spring-loaded annular plug 4 on the external lateral and adjacent end surfaces forms an annular conical channel "without hydraulic connection between each other." The guide 2 with the housing 1 forms the passage channels and is fixed in the housing 1 by a cylindrical sleeve 6 and a sleeve 3 with a conical hole.

The spring-loaded annular plug 4 with the guide 2 is made with the possibility of movement. The guide 2 has a metric thread made at the location of the Belleville springs 5, and is equipped with a shank 8 with a pipe thread. A pipe with a plug is suspended from the pipe thread, inside which a deep borehole pressure gauge is placed, and fixing means 10, for example a cup-like locknut, washer and nut, which are worn on a metric thread, with the possibility of regulating the elasticity of Belleville springs, is attached to the guide 2.

The cylindrical sleeve 6 of the upstream cavitator, installed upstream of the main cavitator, has annular grooves 9 on the outer lateral surface, which form annular venturi tubes with an inner surface of the casing.

It should be noted that the annular plug 4 on the inner surface has, for example, sealing rings 11, and the inner surface of the cylindrical sleeve 6 at the edges from the side of the connection with the tubing has a tapered cut cone 12 in cross section, and from the second edge, on the contrary, expanded 13.

A device for cleaning the bottom-hole zone of a well works as follows.

The working fluid from an energy source, such as a pump (not shown in Fig.) Is supplied, for example, through a tubing string (tubing, not shown in Fig.) Through the inner void of adapter 7, cylindrical sleeve 6, passage channels formed by the housing 1 and the guide 2, and enters the void formed by the conical hole of the sleeve 3 and the annular plug 4, spring-loaded with Belleville springs 5. Through the force created by the springs 5, the pressure increases in this void and the annular plug 4 begins to move into The result is a hydraulic connection between the annular conical channels.

Thus, a high-speed pulsating turbulent annular jet is formed, directed perpendicular to the inner surface of the casing, which creates shock pulses in the bottomhole formation zone. As a result of the outflow of a freely pulsating flooded jet and its interaction with the surface, vapor voids and gas phase bubbles (cavitation voids) of different sizes occur due to discontinuities in the continuity of the fluid flow.

When the pressure head changes in a gas-liquid medium, cavitation voids collapse, which is accompanied by the formation of directed fluid streams with significant kinetic energy, numerous hydraulic shocks occur, local pressure increases in the annulus, as a result of which the annular plug 4 returns to its initial position, Further, the cycle of the device is repeated.

With further movement of the working fluid in the annulus, the fluid enters the annular recesses 9 of the cylindrical sleeve 6 of the upstream cavitator. The annular grooves 9 form annular venturi tubes with the inner surface of the casing, resulting in the formation of additional vapor voids and gas phase bubbles along its entire length, which has an additional effect on the bottomhole formation zone.

Claims (8)

1. A device for cleaning the bottom of the well, containing an energy source and an energy converter connected to it in the form of a multiplier pulse generator, characterized in that the converter is made in the form of upstream and main cavitators, the first of which is made in the form of a cylindrical sleeve, the outer side surface of which has annular grooves with the possibility of formation of annular venturi tubes with the inner surface of the casing, and the main cavitator has a housing in which directing with a shank, on which an annular plug, a sleeve with a tapered bore is put on, a disk spring unit and means for fixing them in such a way that the plug is spring-loaded to the sleeve with a tapered bore, while the guide forms passage channels with the housing and is fixed in the housing by a cylindrical upstream sleeve cavitator and a sleeve with a conical bore, which has the possibility of formation with a spring-loaded annular plug on the outer side and adjacent end surfaces of the conical annular channel la hydraulic fluid from the energy source to generate and annular jet direction to the inner surface of the casing and the working fluid entering the annular groove of the cylindrical sleeve upstream cavitator. 2. The device according to claim 1, characterized in that the inner surface of the cylindrical sleeve along the edges from the side of the connection with the tubing (tubing) has a tapered cut cone in cross section, and from the second edge is expanded. 3. The device according to claim 1, characterized in that the guide has a metric thread made in the place of the Belleville springs, and the shank has a pipe thread 4. The device according to claim 3, characterized in that a pipe with a plug is attached to the pipe thread, made with the possibility of placing a deep borehole pressure gauge in it, and a metric means for fixing plate springs. 5. The device according to claim 1, characterized in that the annular plug on the inner surface has sealing rings. 6. The device according to claim 1 or 5, characterized in that a glass-like locknut, washer and nut are used as fixing means, which are mounted on a metric thread with the possibility of regulating the elasticity of the disk springs. 7. The device according to claim 1, characterized in that the upstream cavitator is configured to connect to an adapter that is connected to the tubing. 8. The device according to claim 7, characterized in that the connections are threaded.

Images