EA015024B1 - Method and apparatus for removing liquid from a gas well - Google Patents

Abstract

A method of removing liquid from a gas well having a production tubing with a restriction therein run into the upper portion thereof and wherein a plunger lift system in arranged within the production tubing, the plunger lift system comprising an upper limiting means, a lower limiting means, a plunger that is capable of moving between the upper and lower limiting means, and a one-way valve situated at or above the upper limiting means that is capable of allowing fluid passage therethrough in an upward direction.

Description

The present invention relates to a method and system for removing liquid from gas wells.

Most gas wells during their operation also provide fluids. Fluids may end up in gas wells as a result of condensation, which occurs when the reservoir pressure is insufficient to ensure that some components remain in the gaseous state; such components are known as condensables, and include water, propane, butane, pentane, propylene, ethylene and acetylene. Another source of fluids in gas wells may be water that enters the gas-bearing formation from aquifers or other water-containing zones.

Gas wells that produce fluids are susceptible to fluid accumulation, with its column being formed at the bottom of the well. Fluid accumulation occurs when the flow rate of the produced gas is insufficient to naturally deliver the fluid to the surface. Liquids are usually transferred to the surface, both in the form of trapped droplets and in the form of a liquid film along the inner surface of the tubing. However, as the gas pressure in the manifold decreases with time, the gas flow rate also decreases. If the gas flow rate falls below the minimum value at which liquids can be delivered from a particular well by a gas stream, that is, below the critical velocity, the reverse fall of the liquid occurs and its accumulation begins. Although the gas can still pass through the liquid column in the form of bubbles or plugs, the hydrostatic equilibrium between the collector pressure and the back pressure created by the accumulated liquid column is ultimately achieved. At this point, the well becomes dead, that is, it does not produce gas, although the corresponding reserves still remain. Therefore, it is necessary to remove the liquid in order to maintain gas production.

Gas wells prone to fluid accumulation may be low pressure wells, in which fluid may begin to accumulate as soon as production begins. Alternatively, fluid-accumulated gas wells may be depleted wells in which the gas flow rate was initially sufficient to lift the fluid to the surface naturally, but then gas production from such a well reduced the reservoir pressure to such an extent that the accumulation of fluid began.

A widely used method of pumping fluid from gas wells is a plunger lift. A plunger lift is a cyclic operation in which the plunger (i.e., the piston) moves reciprocating between two longitudinally spaced positions in the tubing, usually between the lower end of the tubing and the location directly below, near or directly above the wellhead. As a rule, the plunger moves from the lower end of the tubing to the wellhead under the pressure of gas accumulating in the well under the plunger. Gas can accumulate in the well naturally or it can be pumped from the surface. When the plunger moves to the wellhead, it raises a column of fluid accumulated above it. This fluid is then removed from the wellhead, for example, through branch pipes. Usually, the well is stopped (i.e., production is stopped), thereby allowing the embedded system and the plunger to fall along the tubing under the influence of gravity. When the plunger reaches a column of fluid accumulated at the lower end of the tubing, the fluid flows around the plunger over the annular gap between the plunger and the inner surface of the tubing and (or) through the longitudinal channel passing through the plunger and accumulates above the plunger. The well is then transferred to production mode, and the pressure increasing under the plunger raises the plunger and the fluid column to the wellhead. The annular gap between the plunger and the inner surface of the tubing is such that, although liquid may overflow when the plunger falls through the liquid column, there is sufficient gas turbulence in this annular gap when the plunger is raised to create a hydraulic shutter that prevents at least some degree of reverse fall of the fluid located above the plunger.

Various types of plungers can be used in plunger lift systems. For example, two-piece plungers contain two elements that, when connected to each other, are capable of lifting liquids. These two elements of the plunger can independently fall through a rising gas flow or a multi-phase flow of liquid and gas, without significantly interfering with the upward movement of the flow. Therefore, a two-part plunger may be located in a gas well when production is underway, which reduces the time during which the well must be stopped or eliminates the need to stop the well. This can greatly accelerate plunger lift cycles.

Various other methods of extracting fluid from gas wells are also possible, but they all have their drawbacks.

For example, reducing the size of the tubing and thereby reducing the cross-sectional area of the flow can increase the gas flow rate in a given gas well. However, replacing the column is an expensive operation, and as the gas pressure decreases with time, it may be necessary to reduce the column cross-section again.

For extracting liquids from gas wells, it is also possible to use various downhole pumping devices; however, this requires energy consumption and use of expensive equipment to operate.

- 1 015024 ore. In addition, pumps are easily damaged by solid inclusions, such as sand, which may be present in a gas well. Such well pumping devices also experience problems with associated gas interfering with the pumping of fluids.

Alternatively, surfactants or a mixture of surfactants can be introduced into the gas well, which reduce the surface tension of the fluid, so that the foam can be raised at a lower critical rate than the rate required when pumping non-foamed fluid. However, although the use of surfactants is useful in dehydrated gas wells, liquid hydrocarbons do not foam well enough, and the produced fluid may require constant mixing to maintain foaming. The disadvantages of introducing a surfactant or mixture of surfactants into a gas well include the cost of chemicals and possible technical problems associated with the use of these chemicals. In addition, the installation of permanent equipment for the introduction of chemicals can be expensive and technically difficult. Moreover, the metered effect (injection of surfactants into the well) is added to the hydrostatic liquid column, which leads to the limitation of the time window during which the effect is effective.

Plunger lift systems are preferable, as they can operate without energy, and their installation is relatively cheap. In addition, there are ways to determine, prior to installation, whether a plunger lift will work in a given well. In addition, if, for example, for some reason the plunger lift system cannot work, then it can be relatively easily removed from the well, for example, by using an auxiliary wireline cable.

In each of the patents I8 2676547 and 2160291 described device lifting oil or other fluid from wells. The devices contain two plungers, each of which transfers its load only to parts of the well. Patent I8 7080692 discloses a plunger lift device that is installed in the well between the upper and lower plungers.

Existing lift systems still have at least one drawback, since the plunger must be able to move between the lower and upper limiting means, the tubing that is lowered into the well should not have any restrictions that could prevent such a movement. Consequently, some of the existing lift systems cannot be used in a gas well in which the tubing has such constrictions. These constrictions may create well valves or a reduction in the diameter of the tubing. In particular, existing plunger lift systems cannot be used in gas wells in which downhole relief valves are present in the tubing string.

There remains a need for a device and method that overcome or at least mitigate these problems. In particular, there remains a need for an improved device and method for extracting fluid from a gas well, having such restrictions as a non-return valve installed in the production tubing.

In accordance with the first aspect of the invention, a method is proposed for extracting liquid from a gas well with a tubing string having a constriction (constriction means) introduced into its upper part, with a plunger elevator system comprising an upper limiting means, a lower limiting means, a plunger installed in the tubing column adapted to move between the upper and lower limiting means, and a check valve installed at or above the upper limiting means and adapted to pass through Kania fluid upwardly through itself, but not passing it downwards, at which execution:

a) allow the liquid to accumulate in a gas well with a plunger fixed at the upper limiting means, until a liquid column is formed in the tubing above the lower limiting means;

b) release the plunger so that it falls to the lower limiting means through a column of fluid until it comes into contact with the lower limiting means;

c) allow the gas pressure in the gas well to increase under the plunger until the plunger and the liquid column are forcibly raised to the upper limiting means, so that the plunger interacts with the upper limiting means and at least part of the liquid column passes through check valve;

d) repeat steps (a) - (c).

One can imagine that in a cased well, the gas pressure at step (c) may also increase in the annular space between the tubing and the casing.

The method of the present invention can also be used in an inclined borehole, provided that the deviation angle of the borehole from the vertical is less than 60 °, preferably less than 30 °, so that the plunger can fall under the action of gravity along the lift column.

Upper and lower limiting means are simply means preventing the plunger from moving further than required. However, it is preferable that the upper and lower limiting means do not delay the flow of fluid through the tubing.

The check valve can be installed either above or below the constriction in the tubing, up to

- 2 015024 respectfully directly under a narrowing. It is also envisaged that the check valve can be installed at the upper limiting means and can actually act as upper limiting means. If the constriction in the production string is a downhole valve, such as a downhole relief valve of an offshore gas well, the check valve may be separated from the well valve, for example, it may be located above the well valve or it may be incorporated into the well valve. Accordingly, the downhole valve can be a constriction in the tubing and also act as upper limiting means. Alternatively or additionally, the downhole valve may act as a check valve. This is due to the need to ensure relatively easy access during repairs.

If the check valve is above the upper limiting means, it is preferable that the volume of the liquid column formed in the tubing above the lower limiting means is significantly larger than the volume of the tubing between the upper limiting means and the check valve, so that the plunger pushes a significant portion of the liquid column through check valve. Therefore, it is preferable that the check valve is located directly above the upper limiting means.

Preferably, the plunger pushes through the check valve at least 75% of a liquid column, preferably at least 95%.

Preferably, the lower limiting means is located in the tubing at or near the lower end of the string.

In step (a), the gas well is in production mode. However, a gas flow or a multi-phase flow of gas and liquid can flow around a plunger fixed at the upper limiting means through an annular gap between the plunger and the inner surface of the tubing. The gas flow or multiphase flow of liquid and gas then passes through a non-return valve and further to the mouth of a gas well.

Preferably in step (b) the gas well is stopped. Preferably, in step (c), the gas well is started.

The check valve of the plunger lift system prevents the backward fall of the fluid pressed through it down the lift column. As should be well known to a specialist in the field of pumping liquids, the volume of gas increases with decreasing depth due to the expansion of gas at low pressures. Accordingly, the velocity of the gas passed through the check valve may be greater than the velocity of the gas in the lower part of the tubing. This can lead to the phenomenon that in the upper parts of the gas well the gas velocity may exceed the critical velocity. If the gas or multiphase flow through the check valve is above the critical speed, the fluid will naturally rise from the area above the check valve to the wellhead.

If the gas or multiphase flow through the check valve is below the critical speed, the fluid will accumulate above the check valve. Initially, this liquid may be sufficiently stirred to give a gas passage. However, in the end, it may be necessary to artificially lift this fluid accumulated in the tubing above the non-return valve to remove it. Due to the possibly increased gas flow rate or multiphase flow above the non-return valve and (or) a reduced liquid lift distance, the chosen artificial lift method is most likely more effective and / or economical to use in conjunction with the method of the present invention than using only the artificial lift method for delivering fluid from the lower end of the tubing.

Therefore, it is envisaged that the method according to the present invention may also include the operation of artificially raising fluid accumulated in the tubing above the check valve to the mouth of the gas well. For example, surfactants or a mixture of surfactants may be added to the fluid that has accumulated above the check valve, which creates foam that is lifted to the wellhead by a gas flow or a multiphase flow that passes through the check valve.

Alternatively, an additional plunger lift system may be used to lift fluid that has accumulated in the tubing above the check valve. Accordingly, the method according to this invention may also include the following operations:

d) installation of an additional plunger lift system in the tubing above the restriction in the tubing and above the check valve containing the upper limiting means located directly above or directly below the wellhead, the lower limiting means located at the narrowing or above it in the tubing and the return valve or above it, and the plunger, adapted to move between the upper and lower limiting means;

e) allowing another liquid column to accumulate above the constriction in the tubing column and above the check valve with the plunger of an additional plunger lift system attached to the upper limiting means;

g) the release of the plunger additional plunger lift system, so that the plunger PA

- 3 015024 gives to the lower limiting means an additional plunger lift system and through another fluid column until it comes into interaction with the lower limiting means an additional plunger lift system;

h) allowing the gas pressure under the plunger of the additional plunger lift system to increase until the plunger of the additional plunger lift system and another liquid column are forcibly raised to the upper limiting means of the additional plunger lift system, so that the plunger interacts with the upper restrictive means, and removing at least part of the liquid column at the wellhead; and

i) repetition of operations (d) - (i).

Preferably, in step (g), the gas well is stopped. As should be clear to the person skilled in the art, the gas well in step (h) is in production mode.

In accordance with the second aspect of the present invention, there is provided a device for extracting liquid from a gas well with an tubing having a narrowing section introduced into its upper part, the apparatus including a plunger pumping system installed in the tubing and containing upper limiting means, lower limiting means, plunger , adapted to move between the upper and lower limiting means, and a check valve, adapted to pass through itself a flow of fluid introduced px and not letting it down, with a check valve installed at the upper limiting means or above it, the upper limiting means located at the narrowing of the cross section of the tubing or under it, and the lower limiting means located at the place where the gas from the gas well in the tubing accumulated fluid column.

The plunger lift system may also contain fasteners designed to hold the plunger at or near the upper limiting means until it is required to fall. For example, such a fastener may be mechanically or electrically driven means controlled from the surface. Alternatively, the upper fastening means may comprise an electromagnetic fastening means, also controlled from the surface. The power supply to such fastening means can be supplied from accumulators or through an electrical cable laid, for example, along the annular space between the production tubing and the casing of the well and then through the wall of the production tubing.

The plunger lift system may also contain a means for detecting that the volume of the liquid column (hydraulic load) is large enough, so that it is required to allow the plunger to fall to the lower limiting means and through the liquid column until it interacts with the lower limiting means . Such a tool could be, for example, a pressure measurement sensor located at the lower limiting means, where the measured pressure is correlated with the hydraulic load. Thus, the higher the pressure difference between the value at the wellhead and the lower limiting means, the more fluid is in the tubing.

The plunger lift system may also comprise means for detecting that the plunger has reached the lower limiting means. Such means comprise, for example, an electromagnetic sensor, a shock sensor and an acoustic sensor.

The upper limiting means of the plunger lift system is preferably a constriction in the tubing. Alternatively, the upper limiting means may be a local constriction within the tubing.

As discussed above, the check valve can be located above or below the constriction in the tubing. Preferably, the check valve is located below the restriction. More preferably, the check valve itself acts as an upper limiting means. In addition, as discussed above, the check valve can act as a constriction in the tubing. The downhole relief valve may be a contraction, and it may be separated from the check valve, or it may act as a check valve and / or upper limiting means.

To prevent damage to the plunger and (or) the tubing, the plunger lift system may also contain a shock suppressant designed to cushion the blow when the plunger collides with the lower or upper limiting means. The shock absorption means may act as an upper and / or lower limiting means. For example, a shock absorber, such as a spring shock absorber, may serve as the upper or lower limiting means. Alternatively, one or both of the shock absorbers may be attached either directly or indirectly to the plunger itself, for example, the spring damper may be attached to the upper and / or lower surfaces of the plunger.

Typically, the plunger of the plunger lift system has a cylindrical shape with a longitudinal axis of the cylinder aligned with the longitudinal axis of the tubing. Accordingly, the plunger is made of a dense material, such as titanium or steel with electroplated coating. Often the cylindrical surface of the plunger is provided with ribs or grooves contributing to the formation of turbulence in the annular gap between the plunger and the tubing. Normally cylindrical surface

- 4 015024 plunger provided with annular or spiral ribs or grooves.

Preferably, the plunger of the plunger lift system of the present invention consists of two parts. The first part of the plunger can have a channel passing through it, and the second part of the plunger can be adapted to shut off the specified channel when the first and second parts come into contact. The first part can be held at the upper limiting means in step a) (and in step

e) if it is performed), for example, with fastener, while the second part is separated from the first part and may fall to the lower limiting means in step a) (and operation e) if it is done).

Advantageously, the first part may comprise a cylindrical element with which the second part comes into tight contact, blocking the channel, so that the passage of fluid through the channel either stops or substantially decreases.

The channel may be centered in the cylindrical first part or may be offset. Preferably, the longitudinal axis of the channel is aligned with the longitudinal axis of the cylindrical first element. In operation, the two-part plunger is located in the tubing, and the longitudinal axis of the cylindrical first portion is aligned with the axial axis of the tubing. As a rule, the cylindrical first element is located in the lift column above the second part. Preferably, the bottom surface of the cylindrical first element is shaped to mate with the shape of the second part, for example, the second part may be spherical, and the bottom surface of the cylindrical first element may be concave, so that the hermetic contact of the first and second parts can be easily created. Alternatively, the second part may be a rod entering inside the channel of the cylindrical first element. Such rods can be provided with guides, for example, a series of protrusions outward at the base of the rod, so that such a rod remains aligned with the channel of the cylindrical first element.

In use, the cylindrical first element of the two-part plunger is held at the upper limiting means by the fastening means, while the second element falls downward along the lift column to the lower limiting means. If the second element falls, the gas stream or multiphase gas and liquid flow can go up around it. Thus, the second element can fall along the lift column without interrupting gas production. If necessary, the cylindrical first element can be released from the fastening means. When the cylindrical first element falls down through the tubing, it allows the gas flow or multiphase gas and liquid flow up through the channel. Accordingly, the cylindrical first element can also be released from the fastening means while the gas well is in production mode. When the cylindrical first element reaches a column of fluid accumulated over the lower limiting means, the liquid will be forced through the channel of the cylindrical first element and also flow around the plunger through the annular gap between the cylindrical first element and the inner surface of the tubing. When the cylindrical first element reaches the lower limiting means, it is hermetically connected to the second element, which basically interrupts the flow of liquid through the channel of the cylindrical first element. The first and second elements then remain connected to each other at the lower limiting means until the pressure under the two-part plunger increases sufficiently to raise both the two-part plunger and the liquid column above it upwards through the lift. column to the upper limiting means so that at least part of the liquid column was forced through the check valve. It may occur that the pressure is sufficient to lift the two-piece plunger and the corresponding liquid column as soon as the first element reaches the lower limiting means. Alternatively, the well may be blocked until the gas pressure is sufficiently increased.

Usually, the upper limiting means is provided with disconnecting means for disconnecting the first and second elements of the two-piece plunger in hermetic interaction, which depressurizes the channel of the cylindrical first element. Preferably, the disconnecting means does not prevent the passage of fluids upwardly through the channel of the cylindrical first element of the two-piece plunger. Usually, the disconnecting means protrude downward from the upper limiting means, and it can be inserted through the channel of the first element to disconnect the two-part plunger, forcibly withdrawing the second element from the sealed contact with the channel of the cylindrical first element. Usually, the downwardly protruding disconnecting means is a pipe whose length is greater than the length of the channel passing in the cylindrical first element. Alternatively, the downward protruding disconnecting means may be a rod with a diameter smaller than the diameter of the channel and a length greater than the length of the channel of the cylindrical first element. At first, the gas flow rate may be too high for the second element of the two-piece plunger to fall along the lift column. That is, the second element can be held by the gas stream near the channel passing through the first element. However, the second element cannot overlap the channel, since the rod pushes away the second element, preventing tight interaction with the channel, so that the fluid can flow around the second element and pass through the ring

- 5 015024 interval between the channel wall and the rod. If the downward protruding disconnecting means is a pipe, it is preferable that the lower end of the pipe be shaped to reduce the risk that the second element will block the channel in the cylindrical first element, preventing flow through it. For example, the lower end of the pipe may be cut at an angle, or holes may be made at the lower end of the pipe. When the gas flow weakens due to the accumulation of a liquid column in the tubing, the second element will fall to the lower restrictive means of the plunger lift system.

Accordingly, the device of the present invention may comprise an additional plunger lift system comprising upper limiting means located at or near the wellhead and lower limiting means located at or above the constriction in the tubing and above the check valve. If the non-return valve is installed below the restriction in the tubing, the lower limiting means of the additional plunger lift system respectively forms a constriction. If the non-return valve is installed above the restriction in the tubing, a check valve serves as the lower limiting means of the additional plunger lift system. Preferably, the additional plunger lift system also contains fastening means for keeping the plunger at or near the upper limiting means. Preferably, the additional plunger lift system also contains means for detecting that enough liquid has accumulated over the check valve, so that the plunger needs to be allowed to fall. Preferably a means is added for detecting that the plunger of the additional plunger lift system has reached the lower limiting means. Additional plunger lift system may also contain a means of damping shock, similar to that described above. Preferably, the plunger of the additional plunger lift system consists of two parts of the type described above, and in this case, the upper limiting means of the additional plunger lift system is provided with disconnecting means.

If there are more than one tapering in a gas well in a gas well, then in accordance with the invention, an appropriate number of plunger lift systems can be used to successfully lift fluid through each of the tangles in the production string to the wellhead.

If the device according to the invention is at least one additional plunger lift system, then it is provided that the device may also comprise a timer. Such a timer can release the plungers of the systems at different times. Thus, the lower plunger can transfer fluid through a constriction before the upper plunger starts lifting. Such transfer of fluid from one plunger to the next is effective and can prevent the optional lifting of one of the plungers, in particular when there is little or no fluid above the plunger.

Hereinafter, the invention will be described solely in an illustrative manner with reference to FIG. 1, which shows a simplified cross-section of the production tubing of an offshore gas well with a device made in accordance with the present invention.

In accordance with FIG. 1, the device comprises first and second plunger lift systems located in the lift column (4), respectively, below and above the downhole relief valve (5). The first plunger lift system comprises a plunger (1), upper limiting means (2), lower limiting means (3) and a one-way check valve (6) located above the limiting means (2) and below the downhole relief valve (5). Alternatively, the downhole relief valve is a check valve and also serves as an upper limiting means. The second plunger lift system comprises a plunger (7), upper limiting means (not shown) and lower limiting means (8) installed above the downhole relief valve (5). The plunger (1) of the first plunger lift system consists of two parts and contains a cylindrical first element (1) and a spherical second element (9), and the first element (1) is provided with a channel (10) passing through it in the longitudinal direction, and has a concave bottom surface (not shown). The upper limiting means (2) of the first plunger lift system is provided with disconnecting means (11), designed to remove the spherical second element (9) of the two-piece plunger from the hermetic clutch with the concave lower surface of the cylindrical first element. Disconnecting means (11) is a pipe extending downward from the upper limiting means (2), with the lower end cut off at an angle. A fastener (not shown), preferably a mechanical assembly, actuated by pressure, is inserted to hold the first element of the spirit part of the plunger (1) at or near the upper limiting means (2). The lower limiting means (3) of the first plunger lift system can optionally be provided with a means of damping the blow. The plunger (7) of the second plunger lift system is also a two-part plunger (7) comprising a cylindrical first element (7) and a spherical second element (12), with the cylindrical first element (7) provided with a channel (13) passing through it is in the longitudinal direction, and has a concave lower surface (not shown). Upper limiting means (not shown) second

- 6 015024 plunger lift system is wellhead equipment or it may be located near wellhead wellhead equipment, and it is provided with disconnecting means (not shown), for example, a rod protruding downward from wellhead equipment, and fastening means (not shown) designed to hold the first element of the two-part plunger of the second plunger lift system at or near the upper limiting means of the second plunger lift system (not shown). Preferably, the fastener is a conventional device such as an oiler. The lower limiting means (8) of the second plunger lift system can optionally be provided with a means of damping the blow.

During operation, the liquid column (14) is allowed to accumulate above the lower limiting means (3) of the first plunger lift system, while the cylindrical first element (1) of the two-part plunger is held at the upper limiting means (2) by fastening means (not shown ). When the volume of the liquid column (14) reaches a critical value at which gas production falls to an unacceptable level, the gas well is usually stopped and the first element (1) of the two-part plunger is released from the fastener (not shown) and allows it fall. When the first element (1) falls, the gas or multiphase mixture of gas and liquid passes through the channel (10). When the cylindrical first element (11) reaches the column (14), the liquid is forced through the channel (10) and through the annular gap between the plunger (1) and the inner surface of the tubular string (4) until the first element (I) comes in sealed contact with the second spherical element (9) of the two-piece plunger. After that, the gas pressure under the two-piece (1 and 9) plunger and, if possible, in the annular space between the tubing and the casing of the cased gas well, is allowed to increase, until the two-piece plunger and the column (14) of the liquid will not be extruded to the upper limiting means (2). In general, the two-part plunger is squeezed out to the upper limiting means (2) when the well is started (displaced by the initial pressure drop that occurs when the well is started). As the two-piece (1 and 9) plunger approaches the upper limiting means (2), a column of fluid above the plunger passes through a check valve. When the two-part plunger of the first plunger lift system of the upper limiting means (2) reaches the second element of the two-piece plunger (9), the second element of the two-piece plunger (9) is forcibly separated from the first element (1) by a release tool (11), and the fastening means is activated (not shown) designed to hold the plunger at the upper limiting means. If the gas flow rate is initially high enough to prevent the second element (9) of the two-piece plunger from falling, then the beveled end of the downward-flowing pipe (11) will prevent the second element (9) of the two-part plunger from passing the gas or the multiphase fluid through the pipe (Ii) When the gas flow rate decreases (for example, due to fluid accumulation), the second element (9) of the two-part plunger will fall to the lower limiting means (3) of the first plunger lift system. Then the cycle can be repeated.

The fluid raised through the check valve (6) by the first plunger lift system will accumulate above the check valve in the form of a column (15) of fluid. As soon as the volume of the liquid column (15) above the check valve (6) exceeds a certain critical value at which gas production falls to an unacceptable level, the first element (7) of the two-piece plunger of the second plunger lift system is released from the fastening means (not shown) and give him the opportunity to fall. When the first element (7) of the plunger of the second plunger lift system reaches the liquid column (15), the liquid begins to be forced through the channel 13, passing in the longitudinal direction through the first element (7), and through the annular gap between the plunger (7) and the inner surface of the lift column (4) until the first element (7) comes into tight contact with the second element (12) of the two-part plunger of the second plunger lift system. The gas is then allowed to accumulate under the plunger (elements 7 and 12) of the second plunger lift system until the plunger and the column (15) of the fluid are squeezed out to the upper limiting means (not shown) of the second plunger lift system. When the plunger of the second plunger lift system reaches the wellhead equipment, the fluid is removed from the wellhead (not shown) through a branch pipe. When the plunger reaches the wellhead, the fastener designed to hold the first element (7) at the wellhead can be activated, and the protruding rod forcibly removes the spherical second element (12) of the two-part plunger from sealed contact with the channel of the cylindrical first element that the second element (12) is given the opportunity to fall to the lower limiting means (8). Then the cycle can be repeated. If desired, the fasteners may be associated with a timer (not shown), so that the first elements (1 and 7) of the first and second plunger lift systems may be allowed to fall at different times.

- 7 015024

Claims (9)

CLAIM 1. A method of extracting fluid from a gas well with an elevator column that has a restriction introduced into its upper part and in which a plunger elevator system is installed comprising an upper restriction means, a lower restriction means, a plunger adapted to move between the upper and lower restriction means, and a check valve installed at or above the upper restriction means and adapted to pass the fluid upward, but not letting it pass downward, moreover, when performing the method: a) provide the opportunity for fluid to accumulate in a gas well with a plunger at the upper restrictive means until a column of liquid forms above the lower restrictive means in the lift column, b) release the plunger so that it falls to the lower restrictive means through a column of liquid until it comes into contact with the lower restrictive means, c) allow the gas pressure in the well to increase under the plunger until the plunger and the liquid column are forcedly raised to the upper restriction means, so that the plunger comes into contact with it, and at least part of the liquid column passes through the check valve, d) repeat steps (a) - (c). 2. The method according to claim 1, in which a plunger is used, comprising two parts: a first part having a channel passing through it and held at the upper restrictive means in step (a), and a second part separated from the first part so that it falls to the lower restrictive means in step (a), and adapted to block the channel of the first part when the first and second parts come in contact with each other. 3. The method according to claim 1 or 2, carried out in a cased gas well, in which at step (c) the pressure in the annular space between the casing and the lift string increases. 4. The method according to any one of the preceding paragraphs, in which additionally: e) install an additional plunger elevator system in the elevator column above the specified narrowing of the cross section in the elevator column and above the check valve, comprising an upper restriction means located directly above or directly below the wellhead, a lower restriction means located at or near the restriction in the elevator column and at or above the check valve, and a plunger adapted to move between the upper and lower restrictive means, f) provide the opportunity for another column of liquid to accumulate over the constriction in the elevator column and above the check valve when the plunger of the additional plunger lift system is held at the upper restrictive means, g) release the plunger of the additional plunger lift system, so that it falls to the lower restrictive means of the additional plunger lift system and through another column of liquid until it comes into contact with this lower restrictive means of the additional plunger lift system, h) allow the gas pressure to increase under the plunger of the additional plunger lift system until the plunger of the additional plunger lift system and another column of liquid are raised to the upper restrictive means of the additional plunger lift system so that the plunger comes into interaction with the upper restriction means, and removing at least a portion of the fluid column at the wellhead, and i) repeat steps (e) - (h). 5. The method according to claim 4, in which the plunger release time is controlled in step (g) so that the plunger interacts with the lower restrictive means of the additional plunger lift system after the indicated part of the liquid column passes through the check valve in step ( in). 6. A device for extracting fluid from a gas well with an elevator column having a restriction introduced into its upper part, the device including a plunger elevator system installed in the elevator column and containing an upper restriction means, a lower restriction means, a plunger adapted to move between the upper and lower restrictive means, and a check valve capable of passing the fluid flow upward and not passing it down and installed at or above the upper restrictive means, By the way, the upper restrictive means is located at or near the constriction in the elevator column, and the lower restrictive means is located at the place where a liquid column accumulates during the extraction of gas from the well in the elevator column, while the plunger elevator system also contains fastening means designed to hold the release of the plunger at or near the upper restrictive means. 7. The device according to claim 6, in which the plunger contains a first part having a channel passing through it, and adapted for connection with the possibility of release with fastening means, and - 8 015024 the second part, detachable from the first part and adapted to block the channel of the first part, when the first and second parts come in contact with each other. 8. The device according to claim 6 or 7, which also includes an additional plunger lift system installed in the elevator column above the first plunger lift system and containing an upper restriction means, a lower restriction means and a plunger adapted to move between these upper and lower restriction means, the lower restriction means is installed at the constriction in the elevator column or above it, and the additional plunger elevator system also contains fastening means designed for Zhaniya releasably plunger at the upper limiting means or the vicinity thereof. 9. The device of claim 8, further comprising a timer for actuating the fastening means of the additional plunger lift system to release its plunger. Eurasian Patent Organization, EAPO Russia, 109012, Moscow, Maly Cherkassky per., 2