RU2506405C1 - Device for implosive treatment of stratum - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil and gas industry, in particular, to the area of secondary recovery for productive stratum by vacuum. Device for implosive treatment contains a hollow housing with depression chamber and packer included into it. Cover is installed at the housing telescopically and fixed by a shear bolt; the cover is connected from the bottom to a rod with variable section and has a limiter. Limiter can interact with inner protrusion of the housing. At that rod with variable section can interact with overflow opening in the housing. The cover is connected to pipe string from the top. The rod with variable section is hollow and it communicates inner space of the pipe string with depression chamber. At that hollow rod with variable section has conical surface tapering bottom-up and having slope angle of 10-20°. The packer is made as interchangeable metal rings and rubber barrel-type seals.

EFFECT: improving reliability and efficiency of the device operation and excluding contamination of the wellhead site with products of implosive treatment.

2 dwg

Description

The invention relates to the oil industry, in particular to the field of secondary exposure to vacuum on the reservoir.

A device for implosive treatment of the formation (patent RU No. 2191897, IPC ЕВВ 43/25, ЕВВ 43/18 publ. 10/27/2002 in bull. No. 30), containing a hollow body with a depression chamber and a packer, characterized in that a cap connected to the rope and having a clamp and a rod of variable cross section, which is installed with the possibility of interaction with the transfer hole of the housing, is telescopically mounted and fixed with a shear screw on the case; a packer and a wedge are placed on the cylindrical surface of the cover, while the outer conical surface of the ina interacts with dies that are radially movable to the housing guide, and the axial movement of the packer relative to the lid is limited on one side by the wedge, and on the other by a latch lock, the lid also has a stopper that is installed to interact with the housing protrusion, and an abutment, installed with the possibility of interaction with the wedge, receiving holes are located below the guide of the housing.

The disadvantages of this device are:

- firstly, the complexity of the design, due to the large number of nodes and parts (dies, wedges);

- secondly, after lifting the device at the wellhead, the depression chamber is disassembled to clean it from the products of the implosion treatment of the formation directly at the wellhead, while the wellhead area is contaminated and the production culture is reduced;

- low reliability of fixing the dies of the device launched on the rope on the walls of the well, due to the low weight of the device (up to 5 kN) and the paraffin wall of the well in the bottomhole formation zone, while the dies slide down the walls of the well and the device is not fixed in the well;

- fourthly, low work efficiency, which is due to the fact that the hollow rod when filling the depression chambers has a constant annular gap, which does not provide a gradual and uniform filling of the depression chambers with implosion treatment products of the formation, therefore, after pressure equalization in the depression chambers and the under-packer space wells in the bottom-hole zone of the reservoir are not extracted contamination.

Also known is a device for implosive treatment of a formation (patent RU No. 2195550, IPC ЕВВ 43/25, ЕВВ 43/18 publ. 12/27/2002 in bull. No. 36), containing a hollow body with a depression chamber and a packer included in it, while the housing is telescopically mounted and fixed with a shear screw, a cover connected to the rope, with a latch, an additional depression chamber and a hollow rod of variable cross-section, which connects the depression chamber of the housing to the additional depression chamber and is installed with the possibility of interaction with the transfer hole the case, the packer and the wedge are placed on the cylindrical surface of the lid, while the outer conical surface of the wedge interacts with the dies, which are radially movable with the housing guide, and the axial movement of the packer relative to the lid is limited on one side by the wedge and on the other by the lid latch, the hollow rod has a limiter installed with the possibility of interaction with the protrusion of the housing, and a stop installed with the possibility of interaction with the wedge, below the guide of the housing are placed receiving holes.

The disadvantages of this device are:

- firstly, the complexity of the design, due to the large number of nodes and parts (dies, wedges);

- secondly, after lifting the device at the wellhead, the depression chamber is disassembled to clean it from the products of the implosion treatment of the formation directly at the wellhead, while the wellhead area is contaminated and the production culture is reduced;

- low reliability of fixing the dies of the device launched on the rope on the walls of the well, due to the low weight of the device (up to 5 kN) and the paraffin wall of the well in the bottomhole formation zone, while the dies slide down the walls of the well and the device is not fixed in the well;

- fourthly, low work efficiency, which is due to the fact that the hollow rod when filling the depression chambers has a constant annular gap, which does not provide a gradual and uniform filling of the depression chambers with implosion treatment products of the formation, therefore, after pressure equalization in the depression chambers and the under-packer space wells in the bottom-hole zone of the reservoir are not extracted contamination.

The closest in technical essence and the achieved result is a device for implosive treatment of the formation (patent RU No. 2194851, IPC ЕВВ 43/25, ЕВВ 43/18 publ. 12/20/2002 in bull. No. 35), containing a hollow body with a depression included in it a camera and a packer, while a cap connected to a rope with a rod of variable cross-section having a limiter that is mounted to interact with the inner protrusion of the case, is telescopically mounted and fixed with a shear screw on the housing; n with the possibility of interaction with the overflow hole of the housing, and on the cylindrical surface of the housing there is a packer, below which there are receiving holes, and the axial movement of the packer relative to the housing is limited on one side by the stop of the housing and on the other by the lid.

The disadvantages of this device are:

- firstly, low reliability associated with the low probability of the shear screw breaking under the influence of excessive pressure when the packer is not seated and the seam is not cut off, and when the device is unloaded to the bottom of the shear, the destruction of the shear screw is also unlikely due to the low weight of the device (up to 5 kN), it is also unlikely that the packer will be sealed in the well due to the pressure drop in the well;

- secondly, low work efficiency, which is due to the fact that the hollow rod when filling the depression chambers has a constant annular gap, which leads to a sharp response of the device and does not provide a gradual and uniform “pulling” of contaminants from remote areas of the bottomhole formation zone and filling them of the depression chamber, therefore, after pressure equalization in the depression chambers and the under-packer space of the well, some of the contaminants remain not extracted in the bottomhole formation zone;

- thirdly, after lifting the device at the wellhead, a depression chamber is disassembled to clean it from the products of the implosion treatment of the formation directly at the wellhead, while the wellhead area is contaminated and the production culture is reduced.

An object of the invention is to increase the reliability and efficiency of the device, as well as the elimination of contamination of the estuarine area with products of implosive treatment of the formation and increasing the culture of production.

The problem is solved by a device for implosive treatment of a formation containing a hollow body with a depression chamber and a packer, a cover connected to the bottom with a variable cross-section rod having a limiter, which is installed with the possibility of interaction with the internal protrusion of the body, is telescopically mounted and fixed with a shear screw the rod of variable cross section is installed with the possibility of interaction with the transfer hole of the housing, and on the cylindrical surface of the housing is placed Ker, below which there are receiving holes, and the axial movement of the packer relative to the housing on the one hand is limited by the emphasis of the housing, and on the other by a lid,

What is new is that the cap is connected to the pipe string from above, and the rod of variable cross-section is hollow and communicates the interior of the pipe string with a depression chamber, while the hollow rod of variable cross-section is equipped with a conical surface that tapers from the bottom up and is made with an angle of inclination of 10-20 ° moreover, the bottom of the hollow body is equipped with a shank with a check valve, passing from bottom to top, while the packer is made in the form of alternating metal rings and rubber barrel seals, with rubber barrel seals Packer features have the ability to radially expand and tightly interact with the inner wall of the well under the weight of the pipe string after the device rests on the bottom of the well.

Figure 1 schematically shows the device assembly before implosion treatment of the reservoir.

Figure 2 schematically shows the device in the process of washing the products of implosion treatment of the reservoir.

A device for implosive stimulation of a formation (see Fig. 1) consists of a hollow body 1 with a depression chamber 2 included and a packer 3. A cover 5 is telescopically mounted and fixed with a shear screw 4 on the body 1 and connected to the bottom with a rod of variable cross section 6, having a limiter 7, which has the ability to interact with the internal protrusion 8 of the housing 1. In the upper part of the cover is installed knockdown valve 9.

On the cylindrical surface of the housing 1 is placed a packer 3, below which there are receiving holes 10, which can be of any cross section. The axial movement of the packer 3 relative to the housing 1 on one side is limited by the stop 11 of the housing 1, and with the other cover 5.

The cover 5 is connected from above to the column pipe 12. The rod of variable cross-section 6 is hollow and communicates the inner space 13 of the pipe string 12 with the depression chamber 2.

The hollow rod of variable cross section 6 is equipped with a conical surface 14, tapering from the bottom up and made with an angle of inclination: a = 10-20 °, which allows you to change the flow area of the transfer hole 15 of the housing 1 during operation.

The rod of variable cross section 6 is installed with the possibility of interaction with the transfer hole 10 of the housing 1.

Bottom of the hollow body 1 is equipped with a shank 16 with a check valve 17, passing from the bottom up.

Packer 3 (see figure 2) is made in the form of alternating metal rings 18 and rubber barrel-shaped seals 19.

The rubber barrel-shaped seals 19 of the packer 3 have the possibility of radial expansion and tight interaction with the inner wall of the well 20 under the weight of the pipe string 12 after the device rests on the bottom 21 (see Fig. 1) of the well 20 (see Fig. 2).

Unauthorized fluid flows are eliminated with seals 22, 23.

The device operates as follows.

At the wellhead 20 (see FIG. 1), the device in its initial position is assembled by means of a sleeve 24 (see FIG. 2) connected to the pipe string 12.

The device is lowered onto the pipe string 12 (see FIG. 1) until the lower end of the liner 16 abuts against the bottom hole 21 of the well 20. During the lowering of the pipe string 12 (see FIG. 1), the check valve 17 is closed, which prevents the depression chamber 2 from filling up downhole fluid, due to which atmospheric pressure is maintained in the depression chamber 2 and in the inner space 13 of the pipe string 2.

Then lift the device above the bottom 21 of the well 20 by 1-2 meters and fix the weight of the device, for example, 140 kN, using the weight indicator installed on the wellhead 20.

Then, the pipe string 12 is partially unloaded to the bottom 21 of the well, for example, by 4-5 kN, with this, the shear screw 4 is destroyed and the cover 5, together with the hollow rod of variable cross section 6 and the relief valve 9, are moved downward relative to the stationary one under the weight of the pipe string 12 case 1, rested on the bottom 21 of the well 20 through the shank 16, while the packer 3 begins to compress, i.e. rubber barrel-shaped seals 19 (see figure 2) of the packer 3 radially expand and enter into tight interaction with the inner wall of the well 20.

The ability to control the destruction of the shear screw 4 and the operation of the packer 3 by the weight indicator improves the reliability of the device and guarantees the sequence of technological operations during the operation of the device.

At the same time, the rod of variable cross section 6 with a large cross section - S passes through the seal 23 of the transfer hole 15 (see Fig. 1) and is placed by the conical surface 14 opposite the inner protrusion 8 of the housing 1. As a result, the transfer hole 15 and the depression chamber 2 partially which initially atmospheric pressure gradually and evenly without sharp jerks begins to fill with liquid from the annular space 25 of the well 20 through the receiving holes 10, thereby creating an implosive effect on the formation 26 through and perforation interval 27.

The conical surface 14, tapering from the bottom up and made with an angle of inclination: a = 10-20 °, which is determined empirically, allows you to smoothly change the throughput of the overflow hole 15, which ensures the most efficient treatment of the formation 26, i.e. uniformly “pulls” pollution products from remote sections of the bottomhole formation zone 26 through the annular space 25 of the well 20 into the depression chamber 2 of the device.

As the depression chamber 2 is filled with liquid and implosion treatment products, the pipe string 12 continues to be unloaded to zero, i.e. until 14 kN is completely unloaded, while the rubber barrel-shaped seals 19 (see FIG. 2) of the packer 3 continue to radially expand and are pressed against the inner wall of the well 20, and the conical surface 14 (see FIGS. 1 and 2) of the hollow rod of variable cross section 6 lowers down until a smaller section - S _{1 of the} hollow rod of variable cross section 6 is established opposite the seal 23, i.e. the transfer hole 15 opens at maximum throughput.

The pressure in the depression chamber 2 and the in-tube space 25 of the well 20 is equalized.

Then they lift the string of pipes 12 by H = 4-5 meters, while the device returns to its original position, i.e. the rod of variable cross-section 6 with the cover 5 and the knock-off valve 9 is raised upward, while the rod of variable cross-section 6 with a large section - S is placed opposite the seal 23 (see figure 2) and seals the transfer hole 15 (see figure 1), and rubber barrel-shaped seals 19 (see FIG. 2) of the packer 3 extend from the inner wall of the well 20 and are radially compressed inward.

Then backwash, for example, in one and a half times the volume of the well 20, i.e. pumping a process fluid, for example fresh water, with a density of 1000 kg / m ³ , from the wellhead 20 into the annulus 25 through a check valve 17, which opens under the pressure of the pumping process fluid, for example 9 MPa, from the depression chamber 2 and the inner space 13 of the pipe string 12 the products of the formation 26 are removed into the gutter tank (not shown in FIGS. 1 and 2); at the end of the washing, the check valve 17 closes.

Conducting a backwash allows you to utilize the products of the formation treatment directly into the gutter, which eliminates the disassembly of the depression chamber to clean it from the products of the implosion treatment of the formation and avoids contamination of the wellhead area, while increasing the production culture.

Further, the load is discharged into the inner space 13 of the pipe string 12 (not shown in FIGS. 1 and 2), for example, a segment of a hollow rod with a diameter of 22 mm and a length of 2 meters. As a result, the knockdown valve 9 (see Fig. 2) is destroyed and the inner space 25 of the well 20 communicates with the inner space 13 of the pipe string 2. Next, the pipe string 12 is lifted with the device at the wellhead 20, while the pipe is being raised by the process fluid 12 from its internal space 13 flows into the annular space 25 of the well 20, which eliminates the overflow of the process fluid from the pipe string 12 when it rises at the wellhead 20 and contamination in the well area. After that, operational equipment is lowered into the well 20 and its operation is continued.

The design of the proposed device can improve the reliability and efficiency of the device, as well as to eliminate contamination of the estuary area with products of implosive treatment of the formation and to increase the production culture during the work.

Claims (1)

A device for implosive treatment of a formation, comprising a hollow body with a depression chamber and a packer, is telescopically mounted and fixed with a shear screw on the body, which is connected from below to a rod of variable cross section having a limiter that is installed to interact with the internal protrusion of the body, the rod of variable cross section is installed with the possibility of interaction with the overflow hole of the housing, and on the cylindrical surface of the housing there is a packer, below which are placed openings, moreover, the axial movement of the packer relative to the housing is limited on one side by the stop of the housing and on the other by a cover, characterized in that the cover is connected to the pipe string from above and the rod of variable cross section is hollow and communicates the interior of the pipe string with a depression chamber, this hollow rod of variable cross section is equipped with a conical surface, tapering from the bottom up and made with an angle of inclination of 10-20 °, and the bottom of the hollow body is equipped with a shank with a check valve, passing from the bottom up, that the packer is in the form of alternating rubber and metal rings barrel-shaped seals, the barrel-shaped rubber packer seals have the ability to radially expand and sealingly engaged with the inner wall of the well under the weight of the pipe string after the stop device downhole.

Images