RU2545232C1 - Device for cleaning of bottom hole formation zone perforation and unsealing zone - Google Patents

Abstract

FIELD: oil-and-gas industry.

SUBSTANCE: proposed device comprises barrel rigidly secured at flow string and provided with holes made in its wall and perforated casing pipe section-case. Said flow string can displace up and down with working elements secured thereat along the case. Said barrel has opposite upper and lower working elements composed by fixed swirler case, swirler and swirler guide cone that make a circular slot. Inner spaces of working elements are aligned with the barrel wall holes. Additionally, said barrel is provided with bypass channel of directed overflow to communicate annulus under lower working element and that above it. Resilient shutter is arranged at the barrel lower end.

EFFECT: higher reliability and quality of cleaning, swabbing effect.

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Description

The invention relates to the oil and gas industry, and in particular to technologies for repairing wells and cleaning the bottom-hole formation zone (PZP).

The prototype of the claimed is a device for cleaning the perforation channels and processing the bottom-hole zone, including rigidly fixed to the tubing - tubing, having the form of a glass with holes in its walls made at an angle, the body and the rotor with holes in its walls, made with the possibility rotation, characterized in that the section of the perforated casing string is used as the device body, while the rotor is equipped with an impeller and sliding bearings rigidly fixed therein, and has It is possible to move the tubing with the device elements fixed on it along the device body. The angle of inclination of the impeller blades is opposite to the angle of inclination of the hole in the barrel wall / RF patent No. 2304700, publ. 08/20/2007 /.

The tubing is constantly moved by the hoist from the surface within the body of the device - a section of perforated casing. The working agent is pumped under pressure through a barrel rigidly fixed to the tubing, namely, through openings in its walls, made at an angle and equally distributed over the barrel cross section. The working agent flows out of the bore holes at high speed onto the impeller, which is rigidly fixed in the rotor. On the impeller blades, the energy of the pressure head of the jets of the working agent is converted into a pressure difference, which creates a moment of rotation on the impeller, rotating it and the rotor around the barrel. Plain bearings provide easy starting and stable rotation of the rotor. The working agent, passing through the impeller, moves to the rotor holes and expires from them in the form of several jets in the direction of the housing wall with perforations. The barrel with holes and the rotor with the impeller in the aggregate are a hydraulic machine or a turbine stage. The jets of the working agent also move in the direction of rotation of the rotor and, in addition, due to the movement of the tubing, along the body of the device, which ensures guaranteed multiple exposure of the jets of the working agent to all perforation holes found in the body and, accordingly, to all channels of perforation of the porous medium.

The prototype device, like the claimed one, is screwed onto the tubing shoe and also has an element generating a tangential flow, and the device is also moved up and down during processing during the perforation interval.

The prototype device is not effective enough for the following reasons.

1. The presence of a rotating element (rotor), which can jam, especially in conditions of a large number of mechanical impurities, determines the unreliability of the device.

2. During operation of the device, the repressive effect on the underlying perforation channels is not excluded; at the same time, when moving up, the device does not create a swab effect.

3. Due to the design features, it is impossible to create an apparatus with sufficient rotor torque and sufficient barrel strength to operate in small diameter casing strings (102 and 114 mm).

4. The design of the prototype device is quite complex and expensive to manufacture.

The problem to be solved and the expected technical result are to increase the efficiency and reliability of the device due to the lack of moving parts and to improve the quality of cleaning by creating a zone of reduced pressure and providing a swabbing effect when the tubing moves up. The device is effective in conditions of a large number of solids and in casing strings of small diameters (102 and 114 mm).

Thanks to two working elements of the device (which increases the multiplicity of processing and the probability of erosion of solid deposits by a factor of two), generating oppositely directed tangential flows, as well as the swabbing effect of an elastic seal and the presence of a zone of reduced pressure, a more complete and high-quality water-based erosion erosion and removal of solid deposits in the channels perforation and, consequently, better cleaning of the bottom hole.

The problem is solved in that the claimed device for cleaning the perforation and decalmatization channels of the bottomhole formation zone, including a barrel rigidly fixed to the tubing, having the form of a glass with holes in its wall, a case-section of a perforated casing string, and there is a possibility moving up and down tubing with the working elements of the device fixed on it along the device body, characterized in that the barrel is equipped externally with two oppositely directed upper and lower other working elements, consisting of a swirler, a swirler and a swirl guide cone, which are stationary relative to the barrel, forming an annular gap, the internal cavities of the working elements are aligned with the holes in the barrel wall, the barrel is additionally equipped with an overflow channel for directed overflow of the working medium, which communicates the annular space under the lower working an element with an annular space above the upper working element, an elastic obturator is rigidly fixed to the lower end of the barrel.

Figure 1 presents the inventive device, figure 2 is a General view of the swirl. Here:

1 - tubing

2 - casing - device housing

3, 4, 5, 6, 7 - perforation channels in the device body

8 - swirl case

9 - swirl

10 - swirl guide cone

11 - bypass channel directional overflow of the working environment

12 - elastic shutter

13 - zone of reduced pressure

14 - barrel device

15 - annular space

16 - upper tangential flow

17 - lower tangential flow.

The bold arrows in Fig. 1 show the directions of the flow of the working fluid pumped from the surface into the tubing 1, including the upper 16 and lower 17 tangential flow, as well as the flow of the working medium through the bypass channel 11.

Unfilled arrows in figure 1 show the direction of removal of the disintegrated squid by the influx of formation fluid from the perforation channels 4, 5, 7.

The arrows in channels 3 and 6 indicate the process of hydromonitor erosion of the squid by tangential flows.

The device is rigidly fixed, for example, screwed onto the tubing shoe 1 or a flexible coiled tubing, and lowered into the perforation zone of the casing 2 using a lift, i.e. combine with the body of the device, after which the device is ready for use.

The combination of elements 8, 9 and 10, rigidly mounted on the barrel 14, the applicants call the working element of the device; while the internal cavities of the working elements are aligned with the holes in the wall of the barrel 14, and the mating sections of the casing of the swirler 8 and the guide cone of the swirl 10 form an annular gap; optimally, the width of the annular gap is determined by the thickness of the swirler 9.

The bypass channel of the directed overflow of the working medium 11 communicates the annular space 15 under the lower working element with the annular space 15 above the upper working element, which avoids repression to the underlying perforation interval during operation of the device.

The device operates as follows.

To start the device into operation, they start pumping the working medium from the surface in the tubing 1 (which can be used effectively any liquids, as well as gas-liquid mixtures of GHS) and at the same time using the hoist to move the tubing string 1 up and down, and accordingly the layout inside the case the claimed device is in the perforation zone of the casing string 2.

The working medium, passing through openings communicating the internal cavity of the barrel 14 with the internal cavity of the swirl case 8, passes through the swirl 9, acquires a rotationally directed movement (directed upward in the upper working element or downward in the lower working element) and expires in the form of directed tangential streams 16, 17 through the annular gap of the corresponding working element, formed by the mating sections of the casing of the swirler 8 and the guide cone of the swirl 10. The combination of elements 8, 9 and 10 of the applicants They are a working element of the device.

Since the device is equipped with the two working elements described above - the upper and lower - and oppositely directed, the tangential flows 16, 17 generated by them expire through the annular gap formed by the mating portions of the swirler body 8 and the swirl guide cone 10 in opposite directions: the upper tangential flow 16 leaves up the annulus 15, and the lower flow 17 also goes up into the annulus 15 through the bypass channel of the directed overflow of the working medium 11. T kaya hydraulic working medium movement scheme provides positive pressure reduction in the zone 13 (injection effect).

Regardless of the direction of movement of the arrangement in the perforation interval, the outflowing tangential flows 16, 17 from the upper and lower working elements, when combined with the perforation channels 3 and 6 of the device body, carry out a liquid-based erosion of solid deposits in the cavity of perforation channels 3 and 6 and excite high-frequency acoustic fluctuations, which also contributes to the effective disintegration of solid deposits (calcifying material).

The perforation channels 4 and 5 located in zone 13 experience a depressive effect, which provokes the influx of formation fluid through them, which carries out disintegrated masonry deposits, which are subsequently removed to the surface by the flow of the working medium.

The elastic shutter 12 has a dual purpose:

1) prevents the tangential flow 17 from going down, bypassing the bypass channel of the directed overflow of the working medium 11, i.e. prevents repressive effects on the perforation channel 7;

2) when the device moves up, it creates a rarefaction zone underneath it, which also contributes to the inflow of formation fluid through channel 7, which removes disintegrated masonry deposits from it (swabbing effect).

The proposed device when moving it up and down in the perforation interval allows you to clean all the perforation channels and, accordingly, the PZP from the squid.

Thus, the efficiency and reliability of the device are improved due to the lack of moving parts and to improve the quality of cleaning by creating a zone of low pressure and providing a swab effect when the tubing moves up. The device is effective in conditions of a large number of solids and in casing strings of small diameters (102 and 114 mm).

Due to the two working elements of the device (which increases the multiplicity of processing and the probability of erosion of solid deposits by a factor of two), generating oppositely directed tangential flows, as well as the swabbing effect of the elastic shutter and the presence of a zone of reduced pressure, a more complete and high-quality water-based erosion erosion and removal of solid deposits from the channels perforation and, consequently, better cleaning of the bottom hole.

Claims (1)

A device for cleaning perforation and decalmatization channels of the bottom-hole formation zone, including a barrel rigidly fixed on a tubing, having the form of a glass with holes in its wall, a body-section of a perforated casing string, and it is possible to move up and down tubing with fixed on it the working elements of the device along the body of the device, characterized in that the barrel is equipped externally with two oppositely directed upper and lower stationary working elements, consisting of movable relative to the barrel of the swirler body, swirl and guide cone of the swirl, forming an annular gap, the internal cavities of the working elements are aligned with the holes in the barrel wall, the barrel is additionally equipped with an overflow channel for the directed overflow of the working medium, which communicates the annulus below the lower working element with the annulus above the upper a working element, an elastic shutter is rigidly fixed on the lower end of the barrel.

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