RU2626842C1 - Wellhead baffle and method for removing solid impurities from wellhead baffle - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: wellhead baffle for liquids and mechanical impurities contains a body with a bottom, in the upper part of which there is a device for separating the gas-liquid flow into phases, and the lower part is a storage tank for liquid and mechanical impurities. Inside the body, there are two vertical pipes, one of which is designed to supply compressed gas to the bottom of the body, and the other one is to discharge liquid mixture with solid impurities. The lower end of the vertical pipe for supplying compressed gas to the bottom of the body is located higher than the lower end of the vertical pipe for discharging liquid mixture with solid impurities. There are pipes in the baffle for wet gas inlet and dry gas outlet. According to the method for removing solid impurities from the wellhead baffle, compressed gas for bubbling is fed through a vertical pipe, which loosens and mixes the solid impurities on the bottom of the baffle body and mixes them with liquid, located in baflle storage tank. After that, the liquid mixture with solid impurities is withdrawn from the baffle through the vertical pipe for mixing the liquid with solid impurities.

EFFECT: ensuring uninterrupted operation of the baffle.

14 cl, 3 dwg

Description

The invention is intended to remove solid (mechanical) impurities, in particular sand (sand sediment), from the bottom of apparatus operating under excessive gas pressure (separators), in particular from a wellhead well chipper. This invention can be applied in the oil, gas, chemical and other industries.

It is known that during the operation of apparatuses into which gas is supplied with liquid and mechanical impurities, operating under excessive gas pressure, a sufficiently large amount of liquid and mechanical impurities gradually accumulate in their bottom. Impurities accumulating on the bottom precipitate, condense, and it is periodically necessary to dispose of them.

Known devices for removing liquid from devices operating under excessive gas pressure, including a drain pipe with a locking device, manually controlled and / or mechanically remotely controlled by a pneumatic or electric drive. Commands for periodic opening and closing of the locking device are formed by a special controller, depending on the amount of accumulated liquid.

For example, from SU 222097, a device is known for automatically removing liquid from an apparatus operating under excessive gas pressure. The device contains a pneumatic software device, a shut-off valve, hydraulic resistance and a pressure switch with a normally closed shut-off element. The pressure switch input is connected to a normally open chamber of the time delay relay, and its output is connected to the atmosphere. The power line of the software device is connected to a normally closed shut-off chamber of the command relay, and through a variable choke to its control chamber and to a normally closed cut-off camera of a time delay relay, whose control chamber is connected through a variable choke to a normally open camera of the command relay and its output line .

It is also known a device for automatically removing liquid from an apparatus operating under excessive gas pressure (SU 203699), which comprises a power supply unit and a pneumatic logic device acting on an actuating shut-off valve mounted on a discharge line. In this case, the pneumatic logic device is connected by means of pulse delay elements to a pressure switch equipped with a blind chamber connected to a discharge line.

In these devices (apparatuses) gas is under excess pressure, liquid and mechanical impurities accumulate in the lower part of the device (apparatus). Periodically, at the command of a special controller or manually, a shut-off drain valve is opened and excess liquid under gas pressure is removed into a special container or pipeline.

The main disadvantage of these devices is that the mechanical impurities deposited at the bottom of the apparatus are not removed, gradually accumulate and create a plug, which can negatively affect the further operation of the apparatus. There is a need to attract additional resources to remove them. In particular, it may be necessary to stop the unit to clean it. All this entails financial losses.

As an alternative, the TORE®TRAP wellhead sand removal system can be used. To remove sand, pressurized water is introduced into the apparatus, which, thanks to the TORE®TRAP device, is mixed with sand and then removed from the apparatus together with sand. However, this device can only be used if there is an additional source of water nearby (near water bodies), or there is a need for an additional device containing a container of water that will be supplied to the device under pressure.

The main disadvantage of this device is the need for an additional source of fluid, which entails additional financial costs.

As the closest analogue, one can take patent RU 2569427, 11.27.2015, from which a wellhead wellhead chipper of liquids and solids is known, including a housing with a lid and a bottom, in the upper part of which there is an apparatus for separating a gas-liquid flow into phases (gas, liquid, and mechanical impurities), and the lower part is a storage tank for liquid and mechanical impurities, in addition, a shell is located around the casing, and in the upper part of the casing there is a pipe for the entrance of gas-liquid sweat Single, while the lower portion of the sleeve tube is mounted to the gas outlet. Accumulated solids (e.g. sand) can be removed through a process hole in the bottom of the housing. However, this procedure requires the attraction of additional labor and requires additional financial investments. In addition, sand located in the sediment at the bottom of the storage tank gradually hardens and the process of its removal is significantly complicated.

The present invention is aimed at developing the uninterrupted operation of the chipper (including its self-cleaning) without attracting additional resources.

The wellhead wellbore chipper of liquids and solids includes a housing with a bottom. An apparatus for separating the gas-liquid flow into phases (gas and liquid, including mechanical impurities) is installed in the upper part of the chipper, and the lower part is a storage tank for liquid and mechanical impurities. Two vertical pipes are located inside the housing, one of which is used to supply compressed gas to the bottom of the housing, and the other to discharge a mixture of liquid with solid impurities.

The lower end of the vertical pipe for supplying compressed gas to the bottom of the housing, as a rule, is positioned higher than the lower end of the vertical pipe to discharge a mixture of liquids with solid impurities to reduce or eliminate the gas content in the drained liquid.

At least one additional vertical pipe may be disposed in the housing for discharging the settled liquid without solid impurities.

The lower end of the additional vertical pipe to withdraw the settled liquid is located above the lower ends of the main vertical pipes for supplying compressed gas to the bottom of the housing and for discharging a mixture of liquid with solid impurities. At the same time, a drainage hole can be located in the upper part of the additional vertical pipe so that after the cycle of removing the settled liquid it (liquid) is not higher than the level of liquid that accumulates in the lower part of the chipper.

Vertical pipes can be located either one in the other, or separately.

At the bottom of the vertical pipe for supplying compressed gas is a gas flow swirl.

A technological hole is made in the bottom of the housing.

Around the housing is a shell, in the lower part of which a technological hole can be made.

The proposed device allows the following method for removing solid impurities from a wellhead wellhead chipper. Through a vertical pipe serves compressed gas for sparging. A gas stream flowing out from the lower end of the pipe loosens and mixes solid impurities at the bottom of the chipper body and mixes them with the liquid in the accumulator tank of the chipper, after which the mixed liquid with solid impurities is removed from the chipper through a vertical pipe for a mixture of liquid with solid impurities. At the same time, compressed gas for bubbling begins to be supplied to the chipper prior to the beginning of the discharge of liquid with solid impurities from the chipper, and cease to be supplied simultaneously with the cessation of the discharge of the mixture from the chipper.

Sludge liquid can be drained by an additional vertical pipe in the periods between removal of a mixture of liquid with solid impurities.

Compressed gas for bubbling can be taken from the pipeline, through which the gas stream with impurities is supplied to the chipper or from the outlet of the fountain fittings of the well or from the annulus formed by the elevator and / or production string lowered into the well.

The invention is illustrated by drawings.

In FIG. 1 schematically shows a General view of the wellhead wellhead chipper liquids and solids with the location of the pipes one in the other.

In FIG. 2 shows the wellhead wellhead chipper of liquids and solids with a shell and with a separate arrangement of vertical pipes.

In FIG. 3 shows a cycle diagram characterizing the operation of the main components in the process of accumulation of liquid and sand and their discharge.

The wellhead wellbore chipper for liquids and solids consists of a vertical housing 1 with a bottom 2. Housing 1 consists of two parts, the upper of which has a device 3 for separating the gas-liquid flow into phases, and the lower part is a storage tank 4 for liquids and solids . In the upper part of the body 1 of the chipper is located pipe 5 for the entry of wet gas. Inside the housing 1 there are two vertical pipes 6 and 7, one of which (6) is designed to supply compressed gas to the bottom 2 of the housing 1, and the other (7) to discharge a mixture of liquid with solid impurities. The lower end 6a of the vertical pipe 6 for supplying compressed gas to the bottom 2 of the housing 1 is located higher than the lower end 7a of the vertical pipe 7 for discharging a mixture of liquid with solid impurities. In the housing 1, it is possible to arrange at least one additional vertical pipe 8 to withdraw the settled liquid without solid impurities. In this case, the end face 8a of the additional vertical pipe 8 for discharging the settled liquid is located above the ends 6a and 7a of the vertical pipes 6 and 7 for supplying compressed gas to the bottom of the body and for discharging a mixture of liquid with solid impurities. In the upper part of the additional pipe, a drainage hole is possible (not indicated in the drawings). At the ends of the pipes, locking devices 6b, 7b and 8b may be located.

Vertical pipes, it is possible to arrange both one in the other (see Fig. 1), and separately (see Fig. 2).

At the bottom of the vertical pipe 6 for supplying compressed gas, a gas flow swirl may be located to more efficiently create a swirl flow.

In the bottom 2 of the housing 1 perform a technological hole 14 for draining the liquid and mechanical impurities into the pipeline disposal system. At the outlet of the hole there is a locking element with a manual or electric pneumatic actuator (not shown in the drawing).

Around the casing 1, it is possible to arrange the shell 9 with the cover 10. The flow of the separated gas flows through the annular gap between the casing 2 and the shell 9. Since the gas entering the chipper from the well has a positive temperature, water and solids do not turn into ice. This allows you to use the chipper without special heating at low ambient temperatures. A technological hole is made in the lower part of the shell (not indicated in the drawings).

It is also possible in housing 1 to place at least one overflow pipe 11 for draining the fluid, which extends from the side of housing 1 and shell 9, while a drain hole is located on an additional pipe at its upper point inside the housing (not shown in the drawing).

Between the housing 1 and the casing 9 it is possible to install a pipe 12 to remove accumulations of liquid and / or mechanical impurities not separated in the apparatus 3 from the bottom of the cavity between the casing 1 and the casing 9.

Downhole estuarine chipper liquids and solids works as follows.

The warm flow of the gas-liquid mixture (gas, liquid, mechanical impurities) is supplied to the vertical housing 1 through the inlet pipe 5 located in its upper part and enters the apparatus 3 for separating the gas-liquid flow with mechanical impurities into phases (gas, liquid, solid), in which, due to gas-dynamic effects (rotation), all kinds of mechanical impurities and liquid are separated from the gas. So, for example, the apparatus 3 for separation into phases may consist of a deflector and a separation bag. When the flow hits the deflector, a significant part of the liquid and mechanical impurities flows down the deflector. For example, when using the mouth of a gas or oil well as part of a strapping, a large amount of liquid and an insignificant amount of mechanical impurities arrive with the gas.

In the case of filling the storage tank 4 with liquid, there are several options for draining it. So, for example, gravity fluid can be drained from the overflow fitting into the overflow pipe 11. It is also possible to drain the fluid through an additional vertical drain pipe 8 through a locking device that can be opened using a manual drive, an air or electric motor. Moreover, in the overflow and additional pipes, drainage holes are provided to exclude stagnation of water in these pipes after a fluid discharge cycle. The liquid levels in the pipes 11 and 8 and in the housing 1 are aligned due to the flow of gas through the drainage holes.

During the operation of the chipper in the bottom 2, mechanical impurities accumulate, in particular sand, which gradually compacts and can turn into an impenetrable stone cork. For this reason, the operation of wells with removal of solids is undesirable. However, when using the proposed device, the use of such wells becomes possible.

To remove the sand sediment from the storage tank 4, it is necessary to loosen the sediment before starting the removal, to support the suspension for a while in suspension in a liquid so that the grains of sand do not settle to the bottom during sparging. To do this, compressed gas is supplied through a vertical pipe 6 under high pressure (greater than in the chipper), the gas exits from the swirl holes (if any), creating a vortex flow. The sand and liquid in the storage tank 4 are mixed. At the command of the controller or manually, the locking device is opened and the mixture of liquid with solid impurities (sand) is discharged through a vertical pipe 7.

Gas for sparging of accumulated liquid and solid impurities can be taken from the pipeline through which the gas stream with impurities is supplied to the chipper or from the outlet of the fountain fittings of the well, as well as from the annulus formed by the lift and / or production string lowered into the well.

Thus, no additional devices containing gas are involved, and gas is taken directly from the well.

In the case of a chipper with a shell, a small part of mechanical impurities between the body and the shell cannot be ruled out. For the selection of mechanical impurities in the lower part of the shell, it is possible to make a technological hole (not indicated in the drawings) and a special drain pipe 12.

In FIG. 1 and 2, position 13 denotes a pipe for the exit of the dried gas.

In FIG. 3 is a cyclic diagram in the form of a graphic image characterizing the operation of the main components of a wellhead wellhead chipper (STR) in the process of accumulation of liquid and sand and their discharge.

The period of time from the moment a gas stream with liquid and sand arrives until the accumulative part of the STR from the liquid and sand is completely empty makes up the production cycle. In the process of working open source software cycles are repeated. The amount of sand entering the STR along with gas depends on the working flow rate of the well, the intensity of the removal of fluid and sand. Since the operation of the well with the removal of a large amount of sand is not allowed, in real conditions the volume of incoming sand is much smaller in volume than the volume of incoming liquid. The manufacturing process usually involves several stages, or phases.

The production work cycle is characterized by a certain structure. The working period consists of the time of accumulation of liquid and mechanical impurities and discharge of the liquid separately without impurities or with impurities. The system for draining the liquid from the storage tank 4 operates as follows:

The moment of inclusion in the work and the beginning of receipt in the STR of the gas flow with liquid and solid impurities (for example, sand) - (τ ₀ ). Liquid and sand, separated from the gas, settle in the storage tank. Sand and liquid sediment levels gradually increase. Well-known level sensors (not shown in the drawings) can be used to monitor the current level values. Periodically, manually or at the command of the controller, at the times (τ ₁ ; τ ₃ ; τ ₅ ), the shut-off device opens and liquid is drained without sand through the drain pipe 8 or 11. After the shut-off devices are shut off at times (τ ₂ ; τ ₄ ; τ ₆ ) drainage of the settled liquid without sand ceases.

To remove sand sediment, you must first mix it with liquid. To do this, in the lower part of the storage tank below the liquid level through the vertical pipe 6, gas is supplied through the shut-off device under excessive pressure. Gas enters through pipe 6 and exits through openings in the swirler (if any). Due to the supply of gas under pressure, sand is mixed with liquid. After some time at the moment (τ ₇ ), the shut-off device on the drain pipe is opened manually or by command of the controller and the mixture of liquid with sand is discharged through the vertical pipe 7 for disposal. After the discharge of liquid with sand at the moment (τ ₈ ), the shut-off device is closed and the next cycle of accumulation and discharge of liquid begins.

The present invention allows for the smooth operation of the chipper without attracting additional resources (and labor) in automatic or manual modes.

Claims (14)

1. A wellhead wellbore chipper for liquids and mechanical impurities, including a body with a bottom, in the upper part of which there is an apparatus for separating gas-liquid flow into phases, and the lower part is a storage tank for liquid and mechanical impurities, and two vertical pipes are located inside the body, one of which is intended for supplying compressed gas to the bottom of the housing, and the other for outputting a mixture of liquid with solid impurities, while the bottom end of the vertical pipe for supplying compressed gas to the bottom the housing is located higher than the lower end of the vertical pipe for discharging a mixture of liquid with solid impurities, in addition, in the chipper pipes are installed for the inlet of wet gas and the outlet of dried gas. 2. The chipper according to claim 1, characterized in that at least one additional vertical pipe is located in the housing for withdrawing the settled liquid without solid impurities. 3. The chipper according to claim 2, characterized in that the end face of the additional vertical pipe for discharging settled liquid is located above the ends of the vertical pipes for supplying compressed gas to the bottom of the body and for discharging a mixture of liquid with solid impurities. 4. The chipper according to any one of claims 1 to 2, characterized in that the vertical pipes are in one another or separately. 5. The chipper according to claim 1, characterized in that in the lower part of the vertical pipe for supplying compressed gas there is a gas flow swirl. 6. The chipper according to claim 1, characterized in that a technological hole is made in the bottom of the housing. 7. The chipper according to claim 1, characterized in that a shell with a lid is located around the housing. 8. The chipper according to claim 7, characterized in that a technological hole is made in the lower part of the shell. 9. The method of removing solid impurities from the wellhead well chipper according to claims 1 to 8, characterized in that compressed gas for bubbling is fed through a vertical pipe, which loosens and mixes solid impurities at the bottom of the chipper body and mixes them with the liquid in the storage tank chipper, after which the mixture of liquid with solid impurities is removed from the chipper through a vertical pipe for a mixture of liquid with solid impurities. 10. The method according to claim 9, characterized in that the compressed gas for bubbling begins to be supplied to the chipper prior to the discharge of liquid with solid impurities from the chipper. 11. The method according to claim 9, characterized in that the supply of compressed gas for bubbling is stopped to be supplied to the chipper simultaneously with the cessation of the discharge of the mixture from the chipper. 12. The method according to claim 9, characterized in that in the periods between removal of the mixture of liquids with solid impurities, the settled liquid is drained through an additional vertical pipe. 13. The method according to claim 9, characterized in that the compressed gas for sparging is taken from the pipeline, through which the gas stream with impurities is supplied to the chipper or from the outlet of the fountain fittings of the well. 14. The method according to claim 9, characterized in that the compressed gas for sparging is taken from the annulus formed by the lift and / or production columns lowered into the well.

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