CN212428769U - Oil gas well underground foam generating device and oil production system - Google Patents

Abstract

The utility model provides an oil gas well is foam generating device and oil recovery system in pit. The utility model provides an oil gas is foam generating device in pit, including oil pipe, sleeve pipe and foam injector, the oil pipe outside is located to the sleeve pipe cover, has the annular space between oil pipe outer wall and the cover inside pipe wall, and the foam injector sets up in the annular space, and the foam injector includes the casing, has in the casing and pours into the chamber into and pours into the passageway into, pours into the chamber into through pouring into passageway and annular space intercommunication, is equipped with on the oil pipe outer wall and pours into the filling hole that the chamber communicates into, and the foam is through pouring into the passageway entering into pour. The utility model provides an oil gas well foam generating device in pit can resume oil gas well flowing ability in the short time, can make oil gas well resume production sooner.

Description

Oil gas well underground foam generating device and oil production system

Technical Field

The utility model relates to an oil field development technical field especially relates to an oil gas well is foam generating device and oil recovery system in pit.

Background

Oil and gas well engineering belongs to the first-level discipline of oil and gas engineering. Oil and gas wells are the essential information and material channels for the exploration and development of underground oil and gas resources.

The average daily oil production of a single well at the initial stage of oil-gas well development is high, natural energy exploitation and secondary oil extraction are mainly used, but after adjustment of multiple rounds and multiple cycles, the water content is gradually increased and even water flooding is caused, so that the oil-gas well stops spraying, but a large amount of residual oil gas still exists in an oil deposit and between a water injection well and an oil production well. In order to continuously produce residual oil and gas and recover the flowing capacity of an oil and gas well, in the prior art, the production is generally recovered by adopting the equal measures.

However, the method of converting the mechanical production to recover the self-injection capability of the oil-gas well has the problems of large one-time investment and long operation time.

SUMMERY OF THE UTILITY MODEL

The utility model provides an oil gas well is foam generating device and oil recovery system in pit, oil gas well is foam generating device in pit can resume oil gas well flowing ability in the short time, can make the oil gas well resume production sooner.

On the one hand, the utility model provides an oil gas well foam generating device in pit, including oil pipe, sleeve pipe and foam injector, the oil pipe outside is located to the sleeve pipe cover, has the annular space between oil pipe outer wall and the cover inside pipe wall, and the foam injector setting is in the annular space, and the foam injector includes the casing, has in the casing and pours into the chamber into and pours into the passageway into, pours into the chamber into the passageway and feeds through with the annular space into, is equipped with on the oil pipe outer wall and pours into the filling hole that the chamber feeds through into, and the foam gets into through pouring into the.

Optionally, the downhole foam generating device of the oil and gas well further comprises a packer arranged between the inner wall of the casing and the outer wall of the oil pipe and used for isolating the annular space, and the packer is positioned on one side of the foam injector, which is away from the wellhead of the oil and gas well.

Optionally, the housing is connected to the outer wall of the tubing, and the injection passage extends in the axial direction of the tubing.

Optionally, the injection cavity is located at an upper portion of the housing, the lower end of the injection passage is located on a bottom wall of the housing, and the upper end of the injection passage extends to a bottom of the injection cavity.

Optionally, the downhole foam generating device of the oil and gas well further comprises a plugging piece arranged in the injection cavity, and the plugging piece can move in the injection cavity and plug or open the upper end of the injection channel.

Optionally, the blocking member is connected to the housing by an elastic member.

Optionally, a connecting rod is connected between the blocking piece and the elastic piece, and the cross-sectional area of the connecting rod is smaller than that of the blocking piece.

Optionally, a baffle is further arranged in the injection cavity, and when the blocking piece blocks the upper end of the injection channel, a gap is formed between the baffle and the blocking piece;

the baffle plate is provided with a positioning hole, the connecting rod penetrates through the positioning hole, and the cross-sectional area of the positioning hole is smaller than the maximum cross-sectional area of the plugging piece.

Optionally, an inflation chamber is arranged on the inner top wall of the injection cavity, and a piston rod moving along the axial direction of the oil pipe is arranged in the inflation chamber; one end of the elastic piece is connected with the plugging piece, and the other end of the elastic piece is connected with the piston rod.

On the other hand, the utility model provides an oil recovery system, including the production tree and as above oil gas well foam generating device in pit, the production tree setting at the well head of oil gas well and with oil pipe intercommunication, and the production tree have with the intercommunication mouth of annular space intercommunication, pour into the foam in the production tree by the intercommunication mouth get into in the annular space.

The utility model provides an oil gas well foam generating device and oil recovery system in pit, through set up the foam injector in the annular space between oil pipe and sleeve pipe, utilize the foam injector to pour into the foam in the oil pipe, the foam mixes the output with the liquid in the oil pipe to this reduces crude oil (natural gas) water viscosity, makes the oil gas well resume the flowing ability; specifically, be provided with the injection chamber and the injection channel of intercommunication in the casing of foam injector, injection channel and annular space intercommunication, the foam that gets into the annular space gets into through the injection channel and pours into the intracavity into, through set up on the oil pipe outer wall with pour into the filling hole of chamber intercommunication into, the foam that pours into the intracavity passes through the filling hole and gets into in the oil pipe with liquid mixing. The utility model discloses a set up the foam injection ware and pour into the foam into to oil pipe in, resume the flowing ability of oil gas well, the structure of foam injection ware is comparatively simple, and the cost is lower, and can make the oil gas well resume production in the short time, and efficiency is higher.

Drawings

In order to illustrate the embodiments of the present invention or the technical solutions in the prior art more clearly, a brief description will be given below of the drawings required for the description of the embodiments or the prior art, and it is obvious that the drawings in the following description are some embodiments of the present invention. For a person skilled in the art, without inventive effort, further figures can be obtained from these figures.

Fig. 1 is a schematic structural diagram of an underground foam generating device for an oil and gas well according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of another downhole foam generating device for an oil and gas well according to an embodiment of the present invention;

fig. 3 is a schematic view illustrating the cooperation between the baffle and the connecting rod according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a plenum chamber provided in an embodiment of the present invention;

fig. 5 is a schematic structural diagram of an oil recovery system according to an embodiment of the present invention.

Description of reference numerals:

1-an oil pipe; 11-an injection hole; 12-a nozzle; 2-a sleeve; 3-a foam injector; 31-a housing; 311-an implantation chamber; 312 — an injection channel; 313-a closure; 314-a resilient member; 315-connecting rod; 316-a baffle; 3161-positioning holes; 317-a plenum chamber; 3171-a piston rod; 4-an annular space; 5-a packer; 6-Christmas tree; 61-a communication port; 7-connecting the beams.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.

In the initial stage of development of the oil-gas well, natural energy (crude oil and natural gas) is mainly exploited, or secondary oil extraction is carried out, the oil-gas well has high output and high operation efficiency; after adjustment for multiple rounds and multiple cycles, the water content in the oil-gas well gradually rises and even is flooded in the later development period, and finally the oil-gas well stops jetting.

Although the oil and gas well stops spraying, a large amount of residual oil and gas still exist in the oil deposit, and a large amount of residual oil and gas also exist between the water injection well and the oil production well, and the oil and gas cannot be utilized due to the fact that the oil and gas well stops spraying.

In order to be able to continue producing residual hydrocarbons, it is necessary to restore the hydrocarbon well's flowing capacity. In the prior art, the self-blowing capacity of an oil-gas well is generally recovered by adopting modes such as machine-to-machine recovery and the like. However, the method of converting mechanical production is adopted to recover the self-blowing capacity of the oil-gas well, so that the investment is large at one time, the operation time is long, and the operation efficiency is low.

In order to make the oil gas well can resume the flowing ability in the short time, this embodiment provides an oil gas well foam generating device and oil recovery system in pit to make the oil gas well resume the flowing ability in the short time, make the oil gas well resume production sooner.

Example one

Fig. 1 is a schematic structural diagram of an underground foam generating device for an oil and gas well according to an embodiment of the present invention; fig. 2 is a schematic structural diagram of another downhole foam generating device for an oil and gas well according to an embodiment of the present invention; fig. 3 is a schematic view illustrating the cooperation between the baffle and the connecting rod according to an embodiment of the present invention; fig. 4 is a schematic structural diagram of a plenum chamber according to an embodiment of the present invention.

As shown in fig. 1 to 4, the present embodiment provides an oil gas well downhole foam generating device (hereinafter referred to as foam generating device), the foam generating device includes an oil pipe 1, a casing 2 and a foam injector 3, the casing 2 is sleeved outside the oil pipe 1, an annular space 4 is provided between an outer wall of the oil pipe 1 and an inner wall of the casing 2, the foam injector 3 is disposed in the annular space 4, the foam injector 3 includes a housing 31, an injection cavity 311 and an injection channel 312 are provided in the housing 31, the injection cavity 311 is communicated with the annular space 4 through the injection channel 312, an injection hole 11 communicated with the injection cavity 311 is provided on an outer wall of the oil pipe 1, foam enters the injection cavity 311 through the injection channel 312 and enters the oil pipe 1 through the injection hole 11.

As shown in fig. 1, the foam generating device provided in this embodiment includes an oil pipe 1, a casing 2 and a foam injector 3, the casing 2 is sleeved outside the oil pipe 1, and in the case of a flowing well, oil gas such as crude oil or natural gas in the well flows into the ground through the oil pipe 1 and enters a gathering flow; for the mechanical production well, the oil pipe 1, the sucker rod and the deep well pump are combined to pump oil to the ground and enter a gathering and transportation process.

The casing 2 is fixedly connected with the well wall of the oil-gas well, the casing 2 and the well wall are usually sealed by cement, after the casing 2 is installed, a perforating gun is used for perforating at a position, corresponding to a target oil layer, on the casing 2, oil gas of the target oil layer flows into the well bottom through a rock stratum, a cement ring and the casing 2, and the oil gas at the well bottom enters the oil pipe 1 and is transmitted to the ground.

The main functions of the sleeve 2 are: 1. reinforcing the well wall and preventing the stratum from collapsing; 2. sealing different oil layers and water layers to realize layered mining; 3. the method is convenient for implementing measure operations such as fracturing, acidizing and the like and maintenance operations; 4. an oil-gas channel is formed and matched with the oil pipe 1 to achieve the purpose of oil extraction.

The mounting sequence of the casing 2 and the oil pipe 1 in the oil-gas well is as follows: after the oil-gas well is drilled, a casing 2 is put into the well, the casing 2 and the well wall are sealed by cement, and an oil pipe 1 is put into the casing 2. The oil pipe 1 is provided with downhole tools such as an oil packer, a pump and the like, a sucker rod is arranged in the oil pipe 1, the sucker rod pulls a piston of the pump to do up-and-down reciprocating motion, and oil gas is pumped to the ground.

For the problem that the oil gas well stops flowing, the oil gas well needs to recover the flowing ability, in the embodiment, the foam injector 3 is arranged in the annular space 4 between the inner wall of the casing 2 and the outer wall of the oil pipe 1, the foam is injected into the oil pipe 1 through the foam injector 3, so that the foam and the liquid in the oil pipe 1 are mixed and produced, the foam can reduce the surface tension of the liquid, the purpose of reducing the water-containing viscosity of crude oil (natural gas) is achieved, and the oil gas well recovers the flowing ability.

As shown in fig. 1, specifically, the housing 31 of the foam generator has an injection cavity 311 and an injection passage 312 therein, the injection cavity 311 is communicated with the injection passage 312, and the injection passage 312 is communicated with the annular space 4, the foam is injected into the annular space 4, the foam in the annular space 4 enters the injection cavity 311 through the injection passage 312, and further enters the oil pipe 1 through the injection cavity 311.

The position that the outer wall of oil pipe 1 corresponds to injection chamber 311 is provided with injection hole 11, and injection hole 11 intercommunication injection chamber 311 and oil pipe 1, the foam that injects in the chamber 311 accessible injection hole 11 gets into in oil pipe 1 to mix with the liquid in the oil pipe 1, with the aqueous viscosity of the interior oil gas of reduction oil pipe 1, resume oil gas well flowing ability.

It should be noted that the foam can be delivered into the annular space 4 from the outside, and the foam can be pressurized and injected into the annular space 4 by a delivery pump or the like, so that the foam in the annular space 4 has a certain speed and pressure, and the foam can smoothly enter the foam injector 3.

In addition, in order to make the foam entering the oil pipe 1 work well and improve the injection pressure and injection speed of the foam, the size of the injection hole 11 formed in the outer wall of the oil pipe 1 may be designed, for example, the injection hole 11 is a circular hole, the hole diameter of the injection hole 11 may be smaller, for example, the hole diameter of the injection hole 11 is between 1 mm and 3mm, so that the foam has a larger pressure and a higher speed when passing through the smaller injection hole 11, the distribution uniformity of the foam in the oil pipe 1 may be improved, and the effect of the foam for reducing the surface tension of the liquid may be improved.

In the present embodiment, the number of injection holes 11 may be set according to the specific conditions of the oil and gas well, for example, in the case of the oil and gas well with low water viscosity, fewer injection holes 11 may be set, for example, 1 injection hole 11 or 2 to 3 injection holes 11; in the case of a crude oil (natural gas) in an oil and gas well with high water viscosity, more water injection holes may be provided, for example, 5 to 8 injection holes 11, or even more injection holes 11, and the plurality of injection holes 11 may be uniformly or non-uniformly distributed in the area where the plurality of injection holes 11 are provided, which is not limited in this embodiment.

As shown in fig. 1, in order to further adjust the spray state of the foam in the oil pipe 1, a nozzle 12 may be provided in the injection hole 11 on the outer wall of the oil pipe 1, and the diameter of the injection hole 11 may be appropriately larger to fit the contour size of the nozzle 12.

The nozzle 12 has a flow passage therein, and the foam enters the oil pipe 1 through the flow passage of the nozzle 12. The flow passages with different shapes and sizes can adjust the form of the foam entering the oil pipe 1.

For example, the flow passage in the nozzle 12 may be a straight flow passage with a smaller diameter, so that the pressure of the foam can be increased, and the foam forms a dispersed mist in the oil pipe 1; the flow passage in the nozzle 12 may also be a variable diameter flow passage, the diameter of the flow passage is gradually reduced from the outer wall of the oil pipe 1 to the inner wall of the oil pipe 1, for example, the flow passage is a tapered passage, so that the pressure of the foam is gradually increased in the flowing process of the foam in the flow passage, the spraying range of the foam can be further increased, the mist degree of the foam can be further refined, and the effect of the foam can be enhanced.

As shown in fig. 1 and 2, in order to enable the foams in the annular space 4 to enter the foam injector 3, a packer 5 can be further arranged between the inner wall of the casing 2 and the outer wall of the oil pipe 1, the packer 5 is used for isolating the annular space 4, and the packer 5 is positioned on one side of the foam injector 3, which is far away from the wellhead of the oil-gas well.

When the foam is moved down by the well head, can cross 3 flow direction shaft bottoms of foam injector, can lose partial foam like this to because the foam has decurrent velocity of flow after getting into annular space 4, including the action of gravity of foam self, most foam can not utilized by foam injector 3, the utilization ratio of the foam that can greatly reduced like this, the foam reduces the effect that the aqueous viscosity of oil gas can not reach the preferred in 1 oil pipe, and is not obvious to the improvement effect of oil gas well recovery flowing ability.

Through the side of deviating from the well head of oil gas well at foam injector 3, set up packer 5 in the below of foam injector 3 promptly, packer 5 is connected between 2 inner walls of sleeve pipe and 1 outer wall of oil pipe, and packer 5 can cut off annular space 4 in the axial.

After the foam enters the annular space 4 from the wellhead, the moving range of the foam is limited in the annular space 4 above the packer 5, and the foam is injected into the annular space 4 under pressure, so that the foam has better fluidity, the foam above the packer 5 can smoothly enter the foam injector 3, and the utilization rate of the foam is higher.

Along with in the foam constantly pours into annular space 4 into, the foam removes to packer 5 top and is blockked, blocks that the foam in packer 5 department produces pressure to the foam of its top, can make in the foam that back got into all gets into foam injector 3 to improve the foam utilization ratio, guarantee that the foam has better effect to the aqueous viscosity that reduces oil gas in oil pipe 1, can shorten the time that the oil gas well resumes the flowing ability simultaneously, improve the operating efficiency.

As shown in fig. 1 and 2, for the installation of the foam injector 3 and the flow of foam in the foam injector 3, in particular, the housing 31 of the foam injector 3 may be attached to the outer wall of the oil pipe 1, and the injection passage 312 may extend in the axial direction of the oil pipe 1.

To secure the foam injector 3 in the annular space 4 between the oil pipe 1 and the casing 2, the foam injector 3 may be mounted on the outer wall of the oil pipe 1, and in some embodiments the housing 31 of the foam injector 3 may be pressed against the outer wall of the oil pipe 1.

Illustratively, a part of the side wall of the housing 31 corresponding to the injection cavity 311 is tightly attached to the outer wall of the oil pipe 1, the surface of the housing 31 attached to the outer wall of the oil pipe 1 is welded or bonded to the outer wall of the oil pipe 1, and the injection holes 11 are formed in the part of the side wall and the outer wall of the oil pipe 1, so that the foam injected into the injection cavity 311 enters the oil pipe 1.

Or, one side of the injection cavity 311 is in an opening form, the opening corresponds to the outer wall of the oil pipe 1, the edge of the opening is tightly attached to the outer wall of the oil pipe 1, the edge of the opening is connected to the outer wall of the oil pipe 1 in a welding or bonding form, the outer wall of the oil pipe 1 and the shell 31 of the foam injector 3 jointly form the injection cavity 311, and only the injection hole 11 is formed in the outer wall of the oil pipe 1.

As shown in fig. 1 and 2, in order to connect the foam injector 3 more firmly, a connection beam 7 may be provided between the housing 31 of the foam injector 3 and the outer wall of the oil pipe 1, and the housing 31 of the foam injector 3 and the outer wall of the oil pipe 1 may be connected by the connection beam 7 to further fix the foam injector 3. For example, the connecting beam 7 may be made of metal such as iron or stainless steel.

The injection channel 312 in the housing 31 may be opened along the axial direction of the oil pipe 1, so that the extension direction of the injection channel 312 is the same as that of the annular space 4, the arrangement of the injection channel 312 is convenient, and the foam flows along the extension direction of the annular space 4 as a whole, which is more favorable for the foam to enter the injection channel 312 and enter the injection cavity 311 along the injection channel 312.

In one embodiment, the injection passage 312 is located in an upper portion of the housing 31, and the injection cavity 311 is located in a lower portion of the housing 31. The inlet of the injection channel 312 may be opened at the top of the housing 31, and the outlet of the injection channel 312 is communicated with the injection cavity 311 below; thus, the foam flowing down the well head, under pressure and gravity, may enter the injection passage 312 directly from the inlet of the injection passage 312.

In another embodiment, the injection chamber 311 may be located at an upper portion of the housing 31, and the lower end of the injection passage 312 may be located on the bottom wall of the housing 31, with the upper end of the diurnal passage extending to the bottom of the injection chamber 311. As shown in fig. 1 and fig. 2, in the present embodiment, for the form in which the injection cavity 311 and the injection passage 312 are arranged along the axial direction of the oil pipe 1, the injection passage 312 may be disposed below the injection cavity 311.

After the foam flows to the lower part of the foam injector 3 along the annular space 4, the packer 5 generates reaction force to the foam due to the blocking of the packer 5, the foam flows upwards and then enters the injection channel 312 from the inlet of the injection channel 312, and the foam overcomes the gravity to enter the injection cavity 311 due to the very light mass of the foam through the injection pressure of the foam and the acting force of the packer 5.

It should be noted that, by arranging the injection passage 312 below the injection cavity 311 and extending the injection passage 312 from bottom to top along the axial direction of the oil pipe 1, the injection condition of the foam can be further controlled to control the working condition of the foam injector 3, so as to control the working condition of the foam injector 3 according to the actual condition of the oil and gas well.

The operation state of the foam injector 3 is controlled under the injection cavity 311 by using the injection channel 312, and specifically, the foam generating apparatus may further include a blocking member 313 disposed in the injection cavity 311 of the foam injector 3, and the blocking member 313 may move in the injection cavity 311 and block or open the upper end of the injection channel 312.

As shown in fig. 1 and 2, by providing a movable blocking member 313 in the injection chamber 311 of the foam injector 3, the blocking member 313 blocks or opens the upper end of the injection passage 312 during the movement, wherein the blocking member 313 can move downward in the injection chamber 311 and block the upper end of the injection passage 312, or the blocking member 313 moves upward to open the upper end of the injection passage 312.

When the plugging member 313 plugs the upper end of the injection passage 312, the foam in the annular space 4 cannot enter the injection cavity 311, and therefore cannot enter the oil pipe 1 through the injection cavity 311; when the closing member 313 opens the upper end of the injection passage 312, the foam in the annular space 4 can enter the injection cavity 311 through the injection passage 312 and then enter the oil pipe 1 through the injection hole 11.

In this embodiment, the foam generator may have two working states, one is that the foam generator is in an open state, and at this time, the foam may enter the oil pipe 1 to reduce the water-containing viscosity of the crude oil (natural gas) in the oil pipe 1; the other is that the foam generator is in a closed state, and at the moment, foam cannot enter the oil pipe 1, cannot be mixed with liquid in the oil pipe 1 and cannot play a role.

In specific application, the working state of the foam generating device can be automatically adjusted by adjusting the specific condition of injecting the foam into the annular space 4, and the foam injector 3 can be adjusted to be in an open state when the liquid in the oil pipe 1 needs to be treated and the self-blowing capacity of the oil-gas well needs to be recovered; and after the oil and gas well normally spouts or the ability of spouting is recovered, the foam injector 3 can be adjusted to be in a closed state.

Specifically, when the blowout of the oil and gas well is stopped and the flowing capacity of the oil and gas well needs to be recovered, the pressure of the foam injected into the annular space 4 can be increased, for example, the injection amount of the foam is increased and the injection speed of the foam is increased, at the moment, the foam flows from the injection channel 312 to the injection cavity 311 under a larger pressure, the pressure of the foam can overcome the gravity of the blocking piece 313 and jack up the blocking piece 313 upwards, and therefore the foam can enter the injection cavity 311 and then enter the oil pipe 1.

After the oil and gas well normally self-spouts or has recovered the self-spouting ability, can reduce the foam pressure of pouring into annular space 4, for example reduce foam injection volume, reduce foam injection speed, even stop to pour into the foam into annular space 4, the foam pressure in annular space 4 drops this moment, shutoff piece 313 because the action of gravity blocks up and is being poured into the passageway 312 upper end, foam injector 3 is closed state this moment.

By arranging the injection channel 312 below the injection cavity 311 and arranging the movable plugging piece 313 in the injection cavity 311, the injection condition of foam is controlled according to the actual condition of an oil-gas well, so that the foam pressure can jack the plugging piece 313 upwards to open the upper end of the injection channel 312, or the plugging piece 313 seals the upper end of the injection channel 312 under the action of self gravity, the working state of the foam injector 3 is controlled, the automation degree of the foam generating device can be improved, and the working efficiency of the foam generating device is improved.

In this embodiment, the operating condition of foam injector 3 is controlled through the effect of foam to shutoff piece 313, and the area of contact of foam and shutoff piece 313 is little, and required power is less, helps energy saving, reduces the injection requirement of foam, is favorable to accelerating the efficiency that oil gas well resumes production.

The blocking member 313 may be made of metal, plastic or other materials, and the blocking member 313 may be solid or hollow, which is not limited in this embodiment. It will be appreciated that the block piece 313 should be guaranteed not to be corroded by the foam, since the block piece 313 will come into contact with the foam.

As shown in fig. 1 and 2, the blocking element 313 can be connected to the housing by means of an elastic element 314. With respect to the securement of the closure member 313 within the injection lumen 311, in some embodiments, the closure member 313 may not be connected to the injection lumen 311, i.e., the closure member 313 may be free to move within the injection lumen 311; alternatively, in order to prevent the blocking member 313 from being moved to an excessive extent to affect the injection cavity 311, the blocking member 313 may be coupled to the inner wall of the housing 31 of the injection cavity 311 by the elastic member 314, for example, the inner wall of the injection cavity 311 and the blocking member 313 may be coupled by a spring.

By connecting the blocking member 313 to the inner wall of the housing 31 by means of the elastic member 314, the elastic member 314 has an elastic force so as not to completely restrict the movement of the blocking member 313, and the blocking member 313 can be moved toward or away from the upper end of the injection passage 312, during which the elastic member 314 can be switched between an extended state and a compressed state.

In order to more easily realize the connection between the blocking member 313 and the elastic member 314, as shown in fig. 1 and 2, in the present embodiment, a connection rod 315 may be connected between the blocking member 313 and the elastic member 314, and a cross-sectional area of the connection rod 315 may be smaller than that of the blocking member 313.

To reduce the impact of the movement of the closure member 313 on the injection cavity 311, the closure member 313 may be spherical, so that the contact or collision between the closure member 313 and the inner wall of the injection cavity 311 is less likely to cause damage to the injection cavity 311. In this case, a connection rod 315 may be disposed between the blocking member 313 and the elastic member 314 in order to facilitate connection of the blocking member 313 and the elastic member 314.

The tie bars 315 may also limit the direction of movement of the blocking member 313, e.g., the tie bars 315 may protrude toward the top wall of the injection chamber 311, which may cause the blocking member 313 to tend to move up and down between the top and bottom of the injection chamber 311, which may enable the blocking member 313 to more quickly and efficiently open or close the upper end of the injection passage 312.

The cross-sectional area of the connecting bar 315 may be smaller than that of the blocking member 313, so that the connecting bar 315 may be prevented from occupying too much space of the injection cavity 311, thereby ensuring smooth flow of foam in the injection cavity 311, and simultaneously preventing the movement of the blocking member 313 from being affected by the excessive volume of the connecting bar 315.

In order to protect the elastic member 314, i.e. the injection cavity 311, and prevent the blocking member 313 from being influenced or damaged by the movement of the elastic member 314 and the injection cavity 311 due to an excessive range, in a possible embodiment, a baffle 316 may be further disposed in the injection cavity 311, and when the blocking member 313 blocks the upper end of the injection channel 312, a gap is formed between the baffle 316 and the blocking member 313; the baffle 316 is provided with a positioning hole 3161, the connecting rod 315 is inserted into the positioning hole 3161, and the cross-sectional area of the positioning hole 3161 is smaller than the maximum cross-sectional area of the blocking piece 313.

As shown in fig. 2 and 3, the baffle 316 is disposed in the injection cavity 311, the baffle 316 is provided with a positioning hole 3161, and the connecting rod 315 passes through the positioning hole 3161, wherein the cross-sectional area of the positioning hole 3161 is smaller than the maximum cross-sectional area of the blocking member 313, and taking the blocking member 313 as a sphere as an example, the cross-sectional area of the positioning hole 3161 is smaller than the cross-sectional area of the central plane of the blocking member 313. In this way, the blocking member 313 is stopped by the stop 316 during the movement in a direction away from the upper end of the injection channel 312, so as to prevent the elastic member 314 from being compressed too much or the blocking member 313 from colliding with the wall of the injection chamber 311.

It should be noted that, as shown in fig. 2, when the blocking member 313 is in a position for blocking the upper end of the injection passage 312, there should be a gap between the blocking plate 316 and the blocking member 313, so that when the foam lifts the blocking member 313, the blocking member 313 has a certain moving space, and the blocking member 313 can move away from the upper end of the injection passage 312, so that the foam can enter the injection cavity 311 through the injection passage 312.

To further control the movement of the closure member 313, as shown in fig. 1, 2 and 4, in some embodiments, the inner top wall of the injection cavity 311 may be provided with an air plenum 317, and a piston rod 3171 moving along the axial direction of the oil pipe 1 may be provided in the air plenum 317; one end of the elastic member 314 is connected to the blocking member 313, and the other end is connected to the piston rod 3171.

By providing the inflation chamber 317 on the inner top wall of the injection chamber 311, and providing the piston rod 3171 axially movable along the oil pipe 1 in the inflation chamber 317, a closed chamber is formed between the piston rod 3171 and the inner wall of the inflation chamber 317, and the closed chamber can be filled with inert gas such as nitrogen or helium.

The elastic member 314 connected to the blocking member 313 is connected to the piston rod 3171, so that when the blocking member 313 moves to drive the elastic member 314 to extend or compress, the elastic force of the elastic member 314 can act on the piston rod 3171, the piston rod 3171 can move in the inflatable chamber 317, and the gas in the inflatable chamber 317 expands or compresses to do work, so that the acting force applied to the elastic member 314 by the blocking member 313 is buffered, thereby protecting the elastic member 314 and prolonging the service life of the elastic member 314.

According to the downhole foam generating device and the oil extraction system for the oil and gas well, the foam injector is arranged in the annular space between the oil pipe and the casing pipe, the foam is injected into the oil pipe by the foam injector, and the foam and the liquid in the oil pipe are mixed and produced, so that the water-containing viscosity of crude oil (natural gas) is reduced, and the self-blowing capacity of the oil and gas well is recovered; specifically, be provided with the injection chamber and the injection channel of intercommunication in the casing of foam injector, injection channel and annular space intercommunication, the foam that gets into the annular space gets into through the injection channel and pours into the intracavity into, through set up on the oil pipe outer wall with pour into the filling hole of chamber intercommunication into, the foam that pours into the intracavity passes through the filling hole and gets into in the oil pipe with liquid mixing. The utility model discloses a set up the foam injection ware and pour into the foam into to oil pipe in, resume the flowing ability of oil gas well, the structure of foam injection ware is comparatively simple, and the cost is lower, and can make the oil gas well resume production in the short time, and efficiency is higher.

Example two

Fig. 5 is a schematic structural diagram of an oil recovery system according to an embodiment of the present invention. As shown in fig. 5, the present embodiment provides an oil production system, which includes a christmas tree 6 and the foam generating device of the first embodiment, the christmas tree 6 is disposed at the wellhead of the oil and gas well and is communicated with the oil pipe 1, the christmas tree 6 has a communication port 61 communicated with the annular space 4, and the foam injected into the christmas tree 6 enters the annular space 4 through the communication port 61.

As shown in fig. 5, the oil recovery system provided by this embodiment includes a christmas tree 6 and a foam generating device, the christmas tree 6 is disposed at a wellhead of an oil-gas well, and the christmas tree 6 is communicated with the oil pipe 1, and is used for conveying oil gas in the oil pipe 1 to a ground gathering and transportation system.

The Christmas tree 6 is also provided with a communication port 61, and the communication port 61 is communicated with the annular space 4 between the oil pipe 1 and the casing 2. The foam is injected through the Christmas tree 6, the foam in the Christmas tree 6 enters the annular space 4 through the communicating port 61, the foam in the annular space 4 enters the injection cavity 311 through the injection channel 312 of the foam injector 3, and then enters the oil pipe 1 through the injection hole 11 on the outer wall of the oil pipe 1 of the injection cavity 311, the foam entering the oil pipe 1 and the liquid in the oil pipe 1 are mixed and produced, so that the purpose of reducing the water-containing viscosity of crude oil (natural gas) is achieved, and the self-spraying capability of the oil-gas well is recovered.

The structure, function and operation principle of the foam generating device are described in detail in the first embodiment, and are not described herein again.

The oil recovery system that this embodiment provided, including production tree and foam generating device, foam generating device includes oil pipe, sleeve pipe and foam injector, injects the foam through the production tree to the annular space between oil pipe and the sleeve pipe, through set up the foam injector in the annular space, foam in the annular space passes through in the foam injector injects the oil pipe, utilizes the effect of foam to liquid in the oil pipe, reduces the water viscosity of oil gas in the oil pipe to make the oil gas well resume the flowing ability. The foam generating device is simple in structure, low in cost, capable of recovering the self-blowing capacity of the oil and gas well in a short time and high in efficiency.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention.

Claims (10)

1. The utility model provides an oil gas is foam generating device in pit, its characterized in that, includes oil pipe, sleeve pipe and foam injector, the cover pipe box is located the oil pipe outside, the oil pipe outer wall with annular space has between the inside pipe wall, the foam injector sets up in the annular space, the foam injector includes the casing, injection chamber and injection channel have in the casing, the injection chamber passes through injection channel with the annular space intercommunication, be equipped with on the oil pipe outer wall with the filling hole of injection chamber intercommunication, the foam passes through injection channel gets into the injection chamber and by the filling hole gets into in the oil pipe.

2. An oil and gas well downhole foam generating device as claimed in claim 1, further comprising a packer disposed between the inner wall of the casing and the outer wall of the tubing and separating the annular space, the packer being located on a side of the foam injector facing away from a wellhead of the oil and gas well.

3. An oil and gas well downhole foam generating device as claimed in claim 2, wherein the housing is connected to an outer wall of the tubing, the injection passage extending in an axial direction of the tubing.

4. An oil and gas well downhole foam generating device as claimed in any one of claims 1 to 3, wherein the injection chamber is located at an upper portion of the housing, the lower end of the injection channel is located on the bottom wall of the housing, and the upper end of the injection channel extends to the bottom of the injection chamber.

5. An oil and gas well downhole foam generating device as claimed in claim 4, further comprising a blocking member disposed within the injection cavity, the blocking member being movable within the injection cavity and blocking or unblocking an upper end of the injection passage.

6. An oil and gas well downhole foam generating device as claimed in claim 5, wherein the block piece is connected to the housing by a resilient member.

7. An oil and gas well downhole foam generating device as claimed in claim 6, wherein a connecting rod is connected between the block piece and the resilient member, the cross-sectional area of the connecting rod being smaller than the cross-sectional area of the block piece.

8. An oil and gas well downhole foam generating device as claimed in claim 7, wherein a baffle is further provided in the injection cavity, and a gap is provided between the baffle and the blocking piece when the blocking piece blocks the upper end of the injection channel;

the baffle plate is provided with a positioning hole, the connecting rod penetrates through the positioning hole, and the cross-sectional area of the positioning hole is smaller than that of the plugging piece.

9. An oil and gas well downhole foam generating device as claimed in claim 6, wherein the inner top wall of the injection cavity is provided with a plenum chamber, and a piston rod moving along the axial direction of the oil pipe is arranged in the plenum chamber; one end of the elastic piece is connected with the plugging piece, and the other end of the elastic piece is connected with the piston rod.

10. An oil recovery system comprising a Christmas tree and the oil and gas well downhole foam generating device of any one of claims 1-9, the Christmas tree being arranged at a wellhead of the oil and gas well and communicating with an oil pipe, and the Christmas tree having a communication port communicating with an annular space, foam injected into the Christmas tree entering the annular space through the communication port.

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