Foam capturing device for gas well

Abstract

The utility model belongs to the field of defoaming treatment of foam-containing gas, and particularly relates to a foam capturing device for a gas well. The foam capturing device for the gas well comprises an air inlet and an air outlet, and further comprises a foam capturing cavity used for being filled with foam capturing filler, the foam capturing cavity is communicated with the air inlet and the air outlet, the foam capturing cavity is connected with a defoaming agent filling mechanism, and the defoaming agent filling mechanism comprises a plurality of defoaming agent outlets formed in the foam capturing cavity. According to the defoaming device, the defoaming agent outlet is additionally formed in the foam capturing cavity to form a defoaming agent filling site, natural gas flow blows away the filled defoaming agent, the foam capturing filler plays a role in capturing the foam, and meanwhile, the mixing effect of the defoaming agent and the foam is enhanced, so that good defoaming is realized; airflow flowing out of the air outlet is prevented from carrying foam to enter a downstream process, and normal production of a gas well is guaranteed.

Description

Technical Field

[0001] The utility model belongs to the field of defoaming treatment of foam-containing gas, and in particular relates to a foam capturing device for a gas well. Background Art

[0002] In the production process of oil and gas fields, when a large amount of liquid accumulates in the wellbore and the formation energy cannot be used to remove the accumulated liquid, it is necessary to implement foam drainage and gas recovery operations, namely foam drainage operations. Although foam drainage operations can remove the accumulated liquid at the bottom of the well, they also bring about the problem of defoaming gas production.

[0003] After natural gas is extracted from the wellhead, it needs to pass through a gravity separator, a pre-filter, a molecular sieve dehydration device, and other treatments to finally obtain a natural gas product that meets the requirements. Among them, the gravity separator performs preliminary gas-water separation on the gas containing foam, the pre-filter realizes secondary dehydration separation, and the molecular sieve dehydration device can play the role of adsorption, drying, and dehydration. In order to avoid the adverse effects of foam in gas production on the production pipeline process, defoaming agents are generally added to the connecting pipeline before the pre-filter for defoaming, but the length of this part of the connecting pipeline is generally short and the defoaming agent and foam cannot be fully mixed, resulting in poor defoaming effect. However, due to the small volume and light weight of the foam, it is very easy to blow out of the pre-filter and enter the molecular sieve dehydration device.

[0004] In actual production, it is found that after entering the molecular sieve dehydration device, the foam is adsorbed on the surface of the molecular sieve packing. After high-temperature drying, a black colloid is formed on the surface of the molecular sieve packing. This black colloid prevents the molecular sieve packing from absorbing water, causing the molecular sieve packing to be contaminated and fail. Therefore, it is necessary to add a set of devices that do not affect the passage of gas but can eliminate liquid foam before the molecular sieve dehydration device, so as to prevent the foam from entering the downstream with the natural gas and affecting the downstream process.

[0005] The Chinese utility model patent with the announcement date of March 6, 2013 and the authorization announcement number of CN202762237U discloses an oil-water catcher, which includes a catch end and a fixed end, the catch end is connected to the fixed end, mesh holes are arranged on the upper and lower ends of the catch end, and a hollow structure (i.e., a foam catch chamber) is formed between the two end faces and the side of the catch end, and steel balls (i.e., foam catch fillers) are arranged in the hollow structure. The foam catch chamber is connected to the air inlet and the air outlet, and when the water, air, and oil mixture passes through the foam catch chamber, the foam contacts the steel balls and is punctured, and becomes liquid reflux, thereby playing the role of foam capture to a certain extent.

[0006] Since gas wells need to produce gas continuously, they carry a large amount of foam, and there are a large number of small-sized foams. This results in the steel wool being unable to effectively capture the foam, and some foam will still enter the downstream process with the airflow, which will have an adverse impact on the normal operation of the downstream process. Utility Model Content

[0007] The utility model aims to provide a foam capture device for a gas well, so as to solve the problem that the defoaming effect of the existing foam capture device needs to be improved.

[0008] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0009] A foam capture device for a gas well comprises an air inlet, an air outlet, and a foam capture chamber for loading foam capture filler. The foam capture chamber is communicated with the air inlet and the air outlet. The foam capture chamber is connected to a defoamer filling mechanism. The defoamer filling mechanism comprises a plurality of defoamer outlets arranged in the foam capture chamber.

[0010] The utility model is an improved invention, which forms a defoaming agent filling site by adding a defoaming agent outlet to the foam capturing chamber. The natural gas flow disperses the filled defoaming agent, and the foam capturing filler enhances the mixing effect of the defoaming agent and the foam while playing the function of capturing foam, thereby achieving good defoaming, preventing the airflow flowing out of the air outlet from carrying the foam into the downstream process, and ensuring the normal production of the gas well.

[0011] Preferably, the foam capture device for gas wells comprises a fiber filter cartridge extending in the up-down direction, the foam capture chamber is an annular chamber surrounding the fiber filter cartridge, and the lower opening of the fiber filter cartridge forms the air inlet.

[0012] Further preferably, the foam capture device for the gas well comprises a top plate, a bottom plate and a side wall plate, the two ends of the fiber filter cartridge extend to the top plate and the bottom plate respectively and are fixed, a stuffing cover plate is also provided between the top plate and the bottom plate, the corresponding parts of the stuffing cover plate, the bottom plate, the fiber filter cartridge and the side wall plate form the foam capture cavity, there is a gap between the stuffing cover plate and the top plate, a gas outflow port is provided on the stuffing cover plate, and the side wall plate is provided with the gas outlet connected to the gap.

[0013] More preferably, the bottom plate is provided with a plurality of liquid outflow holes.

[0014] More preferably, the side wall plate has an interlayer space, the interlayer space forms a defoaming agent storage space, the defoaming agent filling mechanism includes a defoaming agent filling pipe connected to the interlayer space and extending into the foam capturing cavity, and the outlet of the defoaming agent filling pipe forms a defoaming agent outlet.

[0015] Preferably, gas produced in the gas well passes through the foam capture chamber from bottom to top, and multiple rows of defoamer outlets are arranged at intervals in the vertical direction of the foam capture chamber, and each row of defoamer outlets includes multiple defoamer outlets arranged at intervals along the circumference of the foam capture chamber.

[0016] Further preferably, the defoamer filling mechanism comprises a plurality of defoamer filling pipes, outlets of the defoamer filling pipes form defoamer outlets, and the defoamer filling pipes correspond to the defoamer outlets one by one.

[0017] More preferably, the foam capture device for gas wells comprises a cylinder with an interlayer, the inner wall surface of the cylinder constitutes the corresponding cavity wall surface of the foam capture cavity, the interlayer of the cylinder forms a defoaming agent storage space, and the defoaming agent filling pipe is connected to the defoaming agent storage space. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic structural diagram of a foam capture device for a gas well according to an embodiment of the utility model;

[0019] Figure 2 This is a working principle diagram of the foam capture device for gas wells on the gas well production pipeline of an embodiment of the utility model;

[0020] Among them, 1-air inlet; 2-air outlet; 3-foam capture chamber; 4-top plate; 5-bottom plate; 6-side wall plate, 60-interlayer space; 7-fiber filter cartridge, 70-holes; 8-filling cover plate, 80-gas outflow port; 9-gas buffer interval; 10-gas flow channel; 11-foam capture filler; 12-defoaming agent outlet; 13-defoaming agent filling pipe; 14-defoaming agent filling port; 15-installation section; 16-air inlet section; 17-liquid recovery section; 18-air outlet pipeline; 19-air inlet pipeline; 20-liquid discharge pipe; 21-liquid discharge valve. DETAILED DESCRIPTION

[0021] The technical concept of the utility model is to further bury a defoaming agent outflow pipe in the foam capture filter element on the basis of defoaming the foam in the gas production of the gas well by using a foam capture filter element such as a wire mesh filter element (i.e., a foam capture filler). After the defoaming agent flows out of the defoaming agent outflow pipe, the pressurized air flow can blow away the defoaming agent that flows out in a point-like manner. In this way, by setting up multiple defoaming agent outlets, it is convenient to achieve uniform distribution of the defoaming agent in the foam capture cavity. The air flow carrying the foam impacts the foam capture filter element and the defoaming agent, and the mixing effect between the defoaming agent and the foam is enhanced, which is conducive to achieving better elimination of foam in the air flow.

[0022] The utility model relates to a foam capture device for gas wells, comprising a foam capture chamber for loading foam capture filler, the foam capture chamber being connected to an air inlet and an air outlet, an air flow carrying foam enters the device from the air inlet, passes through the foam capture chamber, and then flows out from the air outlet of the device into the downstream, in addition to being filled with foam capture filler, a defoamer outflow pipe is also buried in the foam capture chamber, the defoamer flowing out of the defoamer outflow pipe interacts with the foam capture filler and foam to achieve efficient defoaming, thereby realizing foam capture.

[0023] Furthermore, by optimizing the arrangement of the fiber filter cartridge and the defoamer filling pipe, it is possible to further remove impurities and enhance the efficiency of foam removal, thereby ensuring the normal gas production process of the gas well.

[0024] The implementation process of the utility model is described in detail below in conjunction with specific embodiments.

[0025] The specific embodiment of the foam capture device for gas wells of the utility model is as follows: Figure 1 As shown, it includes an air inlet 1, an air outlet 2, a foam capture chamber 3 and a defoaming agent filling mechanism.

[0026] The air inlet 1 and the air outlet 2 are the air inlet and the air outlet of the device. There is no special requirement for the shape of the air inlet 1 and the air outlet 2. They can meet the gas transmission requirements of the gas well production pipeline. Generally, they can be set to be circular. The airflow carrying the foam mainly passes through the air inlet 1, the foam capture chamber 3 and the air outlet 2, and then enters the downstream process, such as the molecular sieve dehydration process.

[0027] The foam capture chamber 3 is a place for achieving foam defoaming and separation (i.e., foam capture) in the air flow, and is connected to the air inlet 1 and the air outlet 2 to meet the air flow transmission requirements. The design of the foam capture chamber 3 is described as follows:

[0028] like Figure 1 As shown, the foam capture device for gas wells includes a top plate 4, a bottom plate 5 and a side wall plate 6. A fiber filter cartridge 7 is provided between the top plate 4 and the bottom plate 5. Both ends of the fiber filter cartridge 7 extend to the middle of the top plate 4 and the bottom plate 5 and are fixed thereto. A stuffing cover plate 8 is also provided between the top plate 4 and the bottom plate 5. The stuffing cover plate 8 is spaced apart and parallel to the top plate 4. At this time, the corresponding parts of the stuffing cover plate 8, the bottom plate 5, the fiber filter cartridge 7 and the side wall plate 6 form a foam capture chamber 3, which is an annular chamber surrounding the fiber filter cartridge.

[0029] The lower opening of the fiber filter cartridge 7 forms an air inlet 1, a gas outlet 80 is provided on the packing cover plate 8, the gap between the packing cover plate 8 and the top plate 4 forms a gas buffer gap 9, and an air outlet 2 is provided at the side wall plate position corresponding to the gas buffer gap 9. The hollow inner cavity of the fiber filter cartridge 7 forms a gas flow channel 10, and the holes 70 on the fiber filter cartridge 7 form the entrance for the airflow to enter the foam capture chamber, so that the airflow flows through the air inlet 1, the gas flow channel 10, the holes 70 on the fiber filter cartridge, the foam capture chamber 3, the gas buffer gap 9, and flows out from the air outlet 2. The fiber filter cartridge 7 can play a part in filtering out foam and impurities, and can accurately filter solid impurities in the gas, thereby further optimizing the treatment effect on gas production in the gas well.

[0030] The foam capture cavity 3 is filled with a foam capture filler 11, which is a hard mesh. The foam enters the foam capture cavity 3 under the airflow and collides with the foam capture filler 11, and becomes liquid after being broken and flows out of the foam capture cavity 3. A defoamer outlet 12 is also arranged in the foam capture cavity 3, and the defoamer outlet 12 is buried in the foam capture filler 11. The defoamer flowing out of the defoamer outlet 12 is "spread" to the surroundings under the action of the airflow, and counterflow contacts and mixes with the foam carried by the airflow. The presence of the hard mesh foam capture filler 11 further strengthens the interaction between the defoamer and the foam, and strengthens the defoaming effect.

[0031] like Figure 1 As shown, the foam capture filler 11 is a wire mesh filter element, which has high hardness and low cost. The foam capture chamber 3 is connected to a defoamer filling mechanism, which is mainly used to fill the defoamer into the foam capture chamber 3 through the defoamer outlet 12. Generally, the defoamer filling pipe 13 extending into the foam capture chamber is provided to fill the defoamer into the foam capture chamber 3, and its outlet forms the defoamer outlet 12. The design form of the defoamer filling pipe 13 is now described as follows:

[0032] like Figure 1 As shown, the side wall plate 6 is formed by the inner and outer walls being sleeved, and there is an annular interval between the inner and outer walls, which forms an interlayer space 60. The upper end of the outer wall is provided with a defoamer filling port 14 connected to the interlayer space, and the inner wall is provided with a defoamer filling pipe 13, one end of which is connected to the interlayer space 60 and the other end of which extends obliquely upward to the middle of the foam capture chamber 3. The defoamer filling pipes 13 are divided into two rows in the vertical direction, and each row of defoamer filling pipes should be 2 or more and are arranged at intervals along the circumference of the inner wall of the foam capture chamber 3. The defoamer filling pipes 13 need to be reasonably arranged according to actual needs. The more the number of defoamer filling pipes 13, the greater the defoamer consumption. Since the gas is introduced from the bottom and sent out from the top, in order to ensure the effect of the defoamer, the defoamer filling pipes 13 are arranged in an oblique upward manner, so that the introduced defoamer can basically be evenly distributed on the cross section of the foam capture chamber 3 under the action of the airflow, thereby ensuring the effectiveness of the defoaming effect.

[0033] Finally, the defoaming agent and the defoamed liquid flow out from the holes on the bottom plate 5 , and part of the liquid falls from the holes 70 on the fiber filter cartridge 7 . Figure 1 In the invention, the bottom plate is a perforated plate, and the through holes evenly spaced on the perforated plate constitute the liquid outflow holes.

[0034] Figure 2The schematic diagram of the use of the foam capture device for gas wells of the utility model is shown. A foam capture device is added between the gas well pre-filter and the molecular sieve dehydration device. The foam capture device includes an installation section 15, an air intake section 16, and a liquid recovery section 17 which are sequentially arranged at the upper and lower parts. An annular support is arranged in the installation section 15. The foam capture device for gas wells of the above embodiment is placed on the annular support. An air outlet pipeline 18 is connected to the installation section 15. The inlet of the air outlet pipeline 18 is opposite to the air outlet 2 of the foam capture device for gas wells. The air intake section 16 is connected to the air intake pipeline 19. The outlet of the air intake pipeline 19 enters the interior of the device through the air intake section 16, and then enters the foam capture device for gas wells through the air intake 1 of the foam capture device for gas wells. The liquid recovery section 17 is used to receive the liquid flowing out of the foam capture device. The lower part of the liquid recovery section 17 is a concave circular shape and is connected to a discharge pipe 20 and a discharge valve 21. When the liquid contained in the liquid recovery section 17 reaches a certain amount, it is discharged by the discharge pipe.

[0035] During operation, the gas produced by the gas well carrying foam enters the foam capture equipment from the upstream pipeline via the air inlet pipeline 19, and then enters the foam capture device from the air inlet 1 of the foam capture device for the gas well. After the foam is captured in the foam capture chamber 3, the foam is eliminated, and the gas flow flows out of the foam capture device through the air outlet 2, and then enters the downstream process, such as the molecular sieve dehydration device, through the air outlet pipeline 18. Since the foam in the air flow is eliminated, the foam is prevented from contaminating the molecular sieve filler, the service life of the molecular sieve is increased, and the normal production of the gas well is guaranteed.

Claims

1. A foam capture device for a gas well, comprising an air inlet, an air outlet, and a foam capture cavity for filling a foam capture filler, wherein the foam capture cavity is connected to the air inlet and the air outlet, and characterized in that: The foam capture chamber is connected to a defoaming agent filling mechanism, and the defoaming agent filling mechanism includes a plurality of defoaming agent outlets arranged in the foam capture chamber.

2. The foam capture device for gas wells according to claim 1, characterized in that: The foam capture device for gas wells comprises a fiber filter cartridge extending in the up-down direction, the foam capture chamber is an annular chamber surrounding the fiber filter cartridge, and the lower opening of the fiber filter cartridge forms the air inlet.

3. The foam capture device for gas wells according to claim 2, characterized in that: The foam capture device for gas wells includes a top plate, a bottom plate and a side wall plate. The two ends of the fiber filter cartridge extend to the top plate and the bottom plate respectively and are fixed. A stuffing cover plate is also provided between the top plate and the bottom plate. The corresponding parts of the stuffing cover plate, the bottom plate, the fiber filter cartridge and the side wall plate form the foam capture cavity. There is a gap between the stuffing cover plate and the top plate. A gas outflow port is provided on the stuffing cover plate. The side wall plate is provided with the gas outlet connected to the gap.

4. The foam capture device for gas wells according to claim 3, characterized in that: The bottom plate is provided with a plurality of liquid outflow holes.

5. The foam capture device for gas wells according to claim 3, characterized in that: The side wall plate has an interlayer space, which forms a defoaming agent storage space. The defoaming agent filling mechanism includes a defoaming agent filling pipe connected to the interlayer space and extending into the foam capturing cavity. The outlet of the defoaming agent filling pipe forms a defoaming agent outlet.

6. The foam capture device for gas wells according to claim 1, characterized in that: Gas produced in the gas well passes through the foam capture chamber from bottom to top, and multiple rows of defoamer outlets are arranged at intervals in the upper and lower directions of the foam capture chamber, and each row of defoamer outlets includes multiple defoamer outlets arranged at intervals along the circumference of the foam capture chamber.

7. The foam capture device for gas wells according to claim 6, characterized in that: The defoamer filling mechanism comprises a plurality of defoamer filling pipes, outlets of the defoamer filling pipes form defoamer outlets, and the defoamer filling pipes correspond to the defoamer outlets one by one.

8. The foam capture device for gas wells according to claim 7, characterized in that: The foam capture device for gas wells comprises a cylinder with an interlayer, the inner wall surface of the cylinder constitutes the corresponding cavity wall surface of the foam capture cavity, the interlayer of the cylinder forms a defoamer storage space, and the defoamer filling pipe is connected to the defoamer storage space.

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