RU2131017C1 - Well remedial unit - Google Patents

Abstract

FIELD: equipment used in reconstruction of outdated and worn-out wells instead of drilling new ones and in operation of wells with defective flow strings. SUBSTANCE: well remedial unit includes tubing lowered into flow string. Tubing has well oval chambers and/or central nipples having transverse channels and landing socket with removable valve in the form of body with radial channels, axial channel and transverse channels hydraulically connected with axial one, and seals and retainer. Installed inside body is control member connected with rod of shutoff member. Installed to depth below nonsealed part of flow string is additional pipe string. Installed in annulus formed between pipe strings is cement bridge and/or one or several disconnertors hermetically isolating their hollows. In this case, tubing is installed inside additional pipe string and part of surface of well oval chamber above landing socket of removable valve is made squeezed from two sides into internal hollow and/or body of removable valve in central nipple is made with internal longitudinal nonaxial through channels hydraulically connecting hollows of tubing above and below central nipple. EFFECT: increased oil production, prolonged service life, improved reliability of well. 8 cl, 5 dwg

Description

 The invention relates to the oil industry and can be used to reconstruct obsolete and worn-out wells (for example, transferring them from one production facility to another or disaggregating the production facility by simultaneously or periodically operating several productive formations), instead of drilling new understudy wells, and also for well operation with defective (non-tight) production casing or several productive formations.

 A well-known well installation (Mirzadzhanzade A.X. Technology and equipment for oil production. M., Nedra, 1986, p. 118, 129. 130), selected as an analogue, including pumping pipes with shoe check valve lowered into production tubing string , landing units with axial, non-axial and radial channels for installing and fixing the start and operating valves, which are made in the form of a floor case with a seat and external seals, a control bellows element rigidly connected to the valve stem is installed inside the case installed with the possibility of landing in the saddle of the housing.

 A well-known well installation (Yu.V. Zaitsev. A guide on the gas-lift method of operating wells. M., Nedra, 1984, p. 32, 66, 72), selected as the closest analogue, including tubing pipes lowered into the production string. with a shoe check valve, with a disconnecting packer and with borehole oval chambers having transverse channels and off-axis landing slots for gas-lift valves made in the form of a hollow body with axial and transverse channels, seals and a clamp, inside the body it is installed The control bellows element is connected to the valve stem over the seat.

 A well-known downhole installation (RF Patent N 2067164, 6 E 21 B 43/00, 1996), selected as a prototype, includes tubing pipes lowered into the production string with a shoe check valve, landing nipple with inclined radial channels, non-axial through channels and axial passage sections of different internal diameters, in which removable gas lift valves are installed in the form of a hollow body with seals and a clamp, a control bellows element with a rod, Closely related to the shutter of a locking element in the form of a shutter-saddle.

 Known installations are not effective for wells having leaky production tubing strings, or wells operating with two productive oil-gas or oil-oil reservoirs. In the first case, the well cavity is hydraulically connected to an external source of the formation, which can lead to "griffins", a change in well pressure, an increase in water cut, or a breakthrough of gas, resulting in a decrease in well productivity. And in the second case, the installation does not allow the separation of oil-oil or oil-gas flows of different productive formations, as well as the possibility of their operation by the downhole gas-lift method.

 In addition, the downhole oval chamber in the proposed closest analogue has a welded guide element mounted in the inner wall of the chamber above the seat for guiding the valve, which reduces the degree of reliability (tightness) of the installation during operation. And also in the above prototype, the communicating channels of the internal cavity of the tubing above and below the valves are made in the central landing nipples of the removable valves, which is technologically difficult to manufacture, and also leads to an increase in the outer diameters of the central nipples, as a result of which their use for small pipe casing diameters.

 In addition, the sources cited do not provide for the use of combined installation options, at the same time equipped with borehole oval chambers and central landing nipples for removable gas-lift valves.

 The purpose of the invention is to increase the efficiency of well operation, reduce capital investments for drilling new wells and increase the reliability of the installation while expanding its functionality.

 The positive effect of the application of the invention is expressed in increasing oil production and increasing the service life of the well and the reliability of the installation. In particular, the invention can significantly reduce capital investments for additional drilling of backup wells, since old worn-out wells can be reconstructed (updated) using the proposed installation.

The goal is achieved through the following solutions:
an additional string of pipes of constant or variable cross-section is installed to a depth below the leaky section of the production string; in the annular space formed between the pipe strings, a cement bridge and / or one or several hermetically isolating cavities of disconnectors are installed, while tubing ) constant or variable cross-section with downhole oval chambers and / or with central nipples installed inside an additional pipe string, and part of the surface of the downhole the shaft chamber above the seat of the removable valve is pressed from both sides into the internal cavity, and / or the body of the removable valve in the central nipple is made with internal longitudinal non-axial through channels hydraulically communicating tubing cavities above and below the central nipple; these solutions make it possible to isolate leaky zones of the production string of pipes, use downhole equipment for the small diameter of the production string of pipes, operate wells with several productive formations and / or use combined versions of downhole equipment;
the shutter element shutter is made in the form of a piston with longitudinal through channels and is installed above or below the seat surface of the saddle with transverse throttling channels, which is located in the cylinder so that the transverse throttling channels coincide with the cylinder channels;
disconnectors of the additional pipe string are installed above and / or below the leaky section of the production string of pipes, which allows hermetically isolate the damaged or additionally perforated section of the production string of pipes;
the additional pipe string is equipped with one or more downhole oval chambers with removable valves, which allows you to adjust the pressure (flow rate) of the medium of the additional reservoir and / or pump the solution into the sub-packer zone when killing the well, and also provides the ability to remove the valve from the chamber using cable technology for changes in its size and operating parameters;
the additional pipe string and / or tubing is equipped with a column disconnector and / or telescopic connection, which allows you to disconnect the pipe string from the packer for lifting, and / or eliminates the additional stress on the pipe string that occurs when the borehole temperature and pressure change, and also allows the use of combined options packers;
in the annular space between the tubing and the additional pipe string, a disconnector of their cavity is installed to exclude hydraulic communication;
the lower central nipple has a two-stage outer surface with additional transverse channels, and the upper stage forms an annular space with the tubing cavity, which allows the use of traditional valves, for example, type 5G-25, 3G-25, VK 1, etc., and blind plugs;
The tubing and / or additional pipe string are equipped with a check valve to exclude the effect of pipe pressure on the bottom of the well, as well as to fit the packer and / or crimp pipes and downhole equipment;
The tubing under the disconnector is additionally equipped with a borehole oval chamber or a central nipple with a removable valve for pumping the solution into the sub-packer zone when killing the well.

 In FIG. 1 is a flow diagram of a well installation; in FIG. 2 - a central nipple with a removable valve; in FIG. 3 - borehole oval chamber; in FIG. 4 - two-stage central nipple with a traditional valve; in FIG. 5 - central nipple with removable blind plug.

 The installation (Fig. 1) includes tubing 1 tubing 2 lowered into the production string (can be of different diameters) with downhole oval chambers 3 or central nipples 4, or with combined downhole oval chambers 3 and central nipples 4 having transverse channels 5 and mounting socket 6 with a removable valve 7. To a depth below the untight section 8 of the production string 1 (damaged or perforated section in the area of the additional formation), an additional pipe string 9 is installed (may be with different ametrami). In the annular space formed between the pipe columns 1 and 9, there is a cement bridge 10 or one or several cavities 11 of hermetically insulating their disconnectors 12, for example in the form of packers, or a combined version of the cement bridge 10 and disconnector 12 is installed. with downhole oval chambers 3 and / or with central nipples 4 are installed inside an additional pipe string 9. The downhole oval chamber 3 can be equipped with traditional gas lift valves of the type 5G-25, 3G-25, VK-1, M30-25, KU-25 and etc. Disconnectors 12 of the additional pipe string 9 are installed above and / or below the leaky section 8 of the production string of pipes 1. The disconnector 12 may have a check valve 13 for pumping the solution into the sub-packer zone when the formation is plugged. An additional pipe string 9 beneath or above the disconnector 12 may be equipped with one or more downhole oval chambers 14 with removable valves 15 for plugging the formation or regulating the pressure (flow) of the medium. And also, the additional pipe string 9 can be equipped with a column disconnector 16 for lifting the pipe string 9 from the well without a packer 12, and / or a telescopic connection 17 to eliminate excess voltage on the pipe string 9 when the temperature and pressure change. In the annular space between the tubing 2 and the additional pipe string 9, a disconnector 12 (for example, in the form of a packer) of their cavity can be installed. The tubing 2 can be additionally equipped with a check valve 18 to eliminate the effect of pipe pressure on the bottomhole formation zone. Also, the tubing 2 under the packer 12 can be additionally equipped with a downhole oval chamber 3 or a central nipple 4 with a removable valve 7 for killing or regulating the operation of the well.

 The removable valve 7 (Fig. 1, 2) is made in the form of a housing 19 with radial 20, axial 21 and transverse 22 channels hydraulically connected to it, seals 23 and a retainer 24. A control element 25 is installed inside the housing 19 (for example, in the form of a bellows or movable piston) with an outer cylinder 26 having radial channels 27. The control element 25 is connected to the rod 28 of the locking element in the form of a "shutter 29 - seat 30". Moreover, the shutter 29 can be made in the form of a ball, piston, cone, etc. Moreover, the shutter 29 (Fig. 2) in the form of a piston can be installed above (B. I.1) or under (B. I.2) the seat surface of the seat 30, and have longitudinal through channels 31. The internal cavity of the control element 25 can be filled with compressed gas through the charging unit 32 or / and a spiral adjustable spring 33 can be installed in this cavity. The housing 19 of the removable valve in the central nipple 5 is made with internal longitudinal non-axial through channels 34 hydraulically communicating along awns tubing above and below the central pin 4.

 To increase the tightness of the installation, part of the surface 35 of the borehole oval chamber 3 (Fig. 3) above the landing socket 6 for the removable valve is made pressed from both sides into the internal cavity for guiding the removable valve.

 The lower central nipple 4 (Fig. 4) can have two-stage 36 and 37 outer surfaces with additional transverse channels 38, and the upper stage 37 forms an annular space 39 for supplying gas through the channels 38 with the tubing 2 cavity. In this case, the lower nipple 4 can be a removable traditional valve 7 is installed (for example, 5G-25, 3G-25, VK 1) or blind plug 40 (Fig. 5).

 Using a packer or packers 12 (Fig. 1) of an additional pipe string 9, the reliability (tightness, durability) of isolation of the internal cavity 11 or zone of the defect 8 of the production string of pipes 1 from the bottomhole zone of the well increases, or the possibility of simultaneous or periodic operation of several reservoirs appears. Placing the borehole chamber 14 on an additional pipe string 9, above and / or below the packer 12, allows to install a control valve 15 in its socket 6 (Fig. 3) for operation or to install a blind plug 40 (Fig. 5) in order to stop the operation of the corresponding formation.

 Downhole installation works as follows (Fig. 1). When the well is operated by the gas-lift method, the working gas is injected into the tubing cavity 2 or into the annular space between the columns 9 and 2. In this case, the working gas passing through the valves 7 enters the cavity (channel) of the produced formation fluid and provides its rise to the surface, and by lowering the bottomhole pressure, the working gas injection point passes to the underlying valve 7 and, ultimately, the upper valves 7 close with a decrease in pressure at their depth, so that gas flows only through the lower (working) valve 7. When closing When a high-pressure gas is introduced into the tubing cavity 2, its breakthrough through the shoe 2 can be eliminated by using a non-return valve 18 or by installing a blind plug 40 in the lower central nipple 4 (Fig. 5).

 In the installation (Fig. 1), the central nipples 4 have inner bore diameters decreasing from top to bottom, corresponding to the diameters of the valves 7 (Fig. 2) so that they can be sequentially removed and planted into the socket 6. Gas is supplied through the transverse channels 5 of the central nipple 4 or through radial channels 20 (Fig. 2) of the housing 19 into the cavity of the valve 7. At the same time, the shutter 29 (for example, in the form of a ball - Fig. 2, or the piston - BI1) with the control element 25 moves upward, opens the passage section of the valve 7 for gas into the cavity of the mined seams th liquid.

 When using the shutter 29 under the seat 30, it closes with increasing pressure of the medium (Fig. 2 - B.1.2), otherwise the shutter 29, moving downward, opens the valve 7.

 The cavity between the pipe columns or the internal tubing cavity can be used as a replacement chamber for the accumulation of formation fluid during the operation of wells, for example, with periodic gas lift.

 With a downhole gas lift, the production string of pipes 1 is perforated in zone 8 of the additional productive gas formation (Fig. 1), from where formation gas flows through the valve 15 of the chamber 14 into the annular cavity between the pipes 9 and 2. At the same time, the gas pressure after the valve 15 is regulated (stabilized) and / or a predetermined amount of gas entering the cavity between the pipes 9 and 2 is maintained. Further, this gas enters the tubing 2 through the valves 7 and ensures the development and operation of the oil reservoir.

 If it is necessary to transfer the well to a compressor gas lift, a blind plug is installed instead of valve 15 (Fig. 5), which allows hermetically isolating the perforated zone 8 of production casing 1, for example, on an additional gas reservoir.

 When operating two layers, their products are sent to the wellhead separately through the tubing 2 and through the annular space between the pipes 9 and 2, which allows you to adjust the work and measure the flow rate of each layer separately.

Claims (8)

 1. A downhole installation, including tubing (tubing), lowered into the production string, with oval boreholes and / or central nipples having transverse channels and a seat with a removable valve in the form of a housing with transverse radial, axial and hydraulically connected to it channels, seals and a retainer, a cylinder with a channel is installed inside the housing, a control element connected to the rod of the shutter-seat locking element, characterized in that to a depth below the unsealed portion and the production string of pipes installed an additional string of pipes of constant or variable cross-section, in the annular space formed between the pipes, a cement bridge and / or one or more hermetically isolating cavities of disconnectors is installed, while tubing pipes of constant or variable cross-section with bore oval chambers and / or with central nipples are installed inside an additional pipe string, and part of the surface of the borehole oval chamber above the landing socket will be removed The valve is made pressed from both sides into the internal cavity and / or the removable valve housing in the central nipple is made with internal longitudinal non-axial through channels that hydraulically communicate the tubing cavities above and below the central nipple.  2. Installation according to claim 1, characterized in that the shutter element is made in the form of a piston with longitudinal through channels and installed above or below the seat surface of the saddle with transverse throttling channels, which is located in the cylinder so that the transverse throttling channels coincide with the cylinder channels .  3. Installation according to claim 1, characterized in that the disconnectors of the additional pipe string are installed above and / or below the leaky section of the production pipe string.  4. Installation according to claim 1, characterized in that the additional column of pipes and / or tubing is equipped with one or more downhole oval chambers with removable valves for regulating the pressure or flow rate of the medium.  5. Installation according to claim 1, characterized in that the additional pipe string and / or tubing is equipped with a column disconnector and / or telescopic connection.  6. Installation according to p. 1, characterized in that in the annular space between the tubing and additional pipe columns installed disconnector of their cavity.  7. Installation according to claim 1, characterized in that the lower central nipple has a two-stage outer surface with additional transverse channels, the upper stage forming an annular space with the cavity of the tubing.  8. Installation according to claim 1, characterized in that the tubing and / or additional pipe string are equipped with a check valve and / or an oval chamber located below the disconnector or a central nipple with a removable valve.

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