An electrolysis-assisted gas drainage and production device and method

Abstract

An electrolysis-assisted gas drainage and production device and method, which relate to the technical field of oil and gas development engineering, include a hydrogen electrode, an oxygen electrode, a foam generator, and an oxygen discharge pipe. Among them, the foam generator is detachably arranged inside the oil pipe and includes a throttle cover provided with multiple groups of throttle holes. The hydrogen electrode is detachably arranged at a position below the foam generator inside the oil pipe, is insulated from the oil pipe, and the hydrogen electrode can contact the liquid accumulation layer. The oxygen discharge pipe extends vertically into the well and contacts the liquid accumulation layer. The oxygen electrode is arranged in the oxygen discharge pipe and contacts the liquid accumulation layer through the bottom opening of the oxygen discharge pipe, and the hydrogen electrode and the oxygen electrode can be connected to an external power supply to form an electrolysis circuit. Among them, the hydrogen electrode is the cathode and the oxygen electrode is the anode. The present invention replenishes energy for the produced gas by electrolyzing the downhole liquid accumulation to generate hydrogen, and at the same time sets up a foam generation device for generating foam, thereby significantly improving the drainage effect for the bottom-hole formation water liquid accumulation, effectively keeping the well unobstructed, and improving the gas production efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas development engineering, and particularly relates to an electrolysis-assisted gas drainage and production device and method. Background Art

[0002] During the development of gas wells, affected by water production and formation energy, there is often a problem of bottom-hole liquid accumulation. The existence of bottom-hole liquid accumulation will seriously affect the production efficiency of gas wells. Therefore, in response to the liquid accumulation problem, the industry has developed a variety of methods for gas drainage and production, such as foam drainage gas production method, gas lift drainage gas production method, coiled tubing drainage gas production method. Among them, the foam drainage gas production method is to add a corresponding foaming agent to the liquid accumulation layer. The liquid accumulation is stirred by the produced gas and transformed into foam that is easily carried by the gas flow, so that it is carried out of the well together with the produced gas during the gas production process. This method has the characteristics of simple structure and low construction cost, and has been widely used in this field. However, this method has very limited effect on low-pressure and low-yield gas wells with insufficient formation energy. The amount of foam generated is small, and the amount of liquid carried by the produced gas is also low, which affects the effect of the foam drainage method. Obviously, it is very necessary to set up a foaming device dedicated to increasing the foam production. However, some sand grains existing in the liquid accumulation layer can also be carried out by the foam formed by the liquid accumulation layer, which may block the relevant foaming equipment, thus affecting the normal discharge of the foam. Therefore, it is also necessary to treat this part of the sand grains. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide an electrolysis-assisted gas drainage and production device and method, which effectively improve the efficiency of gas drainage and production and ensure the normal operation of the foam drainage method by the synergistic action of two methods: electrolyzing formation water to generate gas for energy supplementation and generating foam, and treating the sand grains carried in the foam.

[0004] To solve the above-mentioned at least one technical problem, the technical solution provided by the present invention is:

[0005] An electrolysis-assisted gas drainage and production device includes a hydrogen electrode, a foaming device, and an oxygen discharge pipe. Among them, the foaming device is detachably arranged inside the oil pipe and above the bottom-hole liquid accumulation layer. The foaming device includes at least one throttle cover that can completely divide the oil pipe into upper and lower parts. Multiple groups of throttle holes are vertically arranged on the throttle cover, which can allow the gas entering the oil pipe to pass through the throttle cover from bottom to top.

[0006] The hydrogen electrode is detachably arranged in a hydrogen electrode nipple. The hydrogen electrode nipple has the same diameter as the oil pipe, and is detachably arranged at the bottom of the oil pipe, and the hydrogen electrode is immersed in the liquid accumulation layer, and its position is higher than the perforation layer.

[0007] The oxygen discharge pipe connected to the ground extends vertically into the well and is immersed in the liquid accumulation layer. Among them, a diameter-expanded oxygen electrode short joint is detachably arranged at the bottom of the oxygen discharge pipe and immersed in the liquid accumulation layer. A cylindrical separation sleeve is detachably sleeved at the bottom of the oxygen electrode short joint. The through hole at the top of the separation sleeve is sleeved on the outer surface of the oxygen electrode short joint, so that the inside of the oxygen discharge pipe is communicated with the inside of the separation sleeve. A gas-liquid separator that only allows liquid to enter the inside of the separation sleeve is arranged at the bottom of the separation sleeve. The oxygen electrode is arranged in the oxygen electrode short joint and immersed in the liquid accumulation layer. The hydrogen electrode and the oxygen electrode can be connected to an external power supply to form an electrolysis circuit. Among them, the hydrogen electrode is the cathode and the oxygen electrode is the anode.

[0008] One embodiment of the present invention is that a fixing ring is detachably arranged inside the hydrogen electrode short joint. The fixing ring can completely divide the inside of the hydrogen electrode short joint into upper and lower parts. Among them, multiple groups of air guide holes communicating the upper and lower parts are arranged on the fixing ring. The hydrogen electrode is arranged through the center of the fixing ring and connected to the ground through a cable.

[0009] Further, the fixing ring is made of insulating ceramic material and is fixed inside the hydrogen electrode short joint by means of threaded connection.

[0010] Further, a fixing ring is also detachably arranged inside the oxygen electrode short joint. The oxygen electrode is arranged through the center of the fixing ring and connected to the ground through a cable.

[0011] One embodiment of the present invention is that the foam generator includes a separation cylinder and a throttle cover. Among them, the throttle cover is a dome-shaped structure with an upward arc surface. It is detachably arranged inside the oil pipe and completely divides the oil pipe into upper and lower parts. Multiple groups of throttle holes are vertically arranged on its dome part to communicate the upper and lower parts separated by the throttle cover;

[0012] The separation cylinder is detachably coaxially arranged on the inner surface of the oil pipe and is connected to the edge of the throttle cover. A sand prevention plate that completely divides the separation cylinder into upper and lower parts is also horizontally arranged inside the separation cylinder. Among them, multiple groups of sand prevention holes are vertically penetrated on the sand prevention plate, and sand prevention covers are correspondingly arranged below the sand prevention holes. The sand prevention cover is a vertical pipe body that continuously reduces in diameter from top to bottom, and its uppermost end is connected with the sand prevention hole with the same diameter;

[0013] An atomization power supply and multiple groups of atomization sheets are arranged on the upper surface of the sand prevention plate. The atomization sheets are correspondingly arranged above the sand prevention holes, and the atomization holes on the atomization sheets are all communicated with the sand prevention holes.

[0014] In addition, the present invention also discloses a method for electrolysis-assisted drainage gas production using the above device, including the following steps:

[0015] Step S1: Arrange an oxygen discharge pipe immersed in the bottom-hole liquid accumulation layer in the wellbore annulus according to the described device structure. An oxygen electrode immersed in the bottom-hole liquid accumulation layer and connected to the ground is arranged inside the oxygen discharge pipe. A foam generator and a hydrogen electrode connected to the ground are sequentially arranged in the tubing from top to bottom. The hydrogen electrode is immersed in the liquid accumulation layer and is located above the perforated layer.

[0016] Step S2: Power the hydrogen electrode and the oxygen electrode to form an electrolytic circuit to electrolyze the liquid accumulation layer, so that the gas generated at the oxygen electrode is discharged from the wellbore along the oxygen discharge pipe, and the gas generated at the hydrogen electrode enters the tubing together with the produced gas, passes through the foam generator, and then is produced.

[0017] In some embodiments, the oxygen discharge pipe is connected to a negative pressure source on the ground.

[0018] In some embodiments, the oxygen discharge pipe is connected to a chlorine separation device on the ground.

[0019] The technical effects achieved by the present invention are as follows:

[0020] 1. By electrolyzing formation water underground in the well, the present invention generates hydrogen to supplement energy for the produced gas, and is provided with a foam generation device for generating foam, so that the carrying efficiency is improved. At the same time, the electrolysis itself can also consume formation water, thereby significantly improving the drainage effect for bottom-hole formation water accumulation, effectively keeping the well unobstructed, increasing the gas production rate, and expanding the applicable range of the foam drainage method.

[0021] 2. In the present invention, a sand removal device is provided to remove the sand particles carried into the throttle cover by the foam, avoiding sand particle blockage of the throttle cover, ensuring normal foam generation in the foam generator, and guaranteeing the normal construction of foam drainage.

[0022] 3. The present invention can effectively separate the anode product and the cathode product, avoiding the risk of combustion and explosion caused by their mixing, thereby effectively ensuring construction safety.

[0023] 4. Compared with other drainage methods, the device structure in the electrolysis method adopted by the present invention is simple, and the construction and maintenance costs are relatively low. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0025] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0026] Figure 2 is the top view of the fixing ring in the present invention;

[0027] Figure 3 is the cross-sectional view of the foam generator in the oil pipe in the present invention;

[0028] Figure 4 is the axonometric view of the foam generator in the present invention;

[0029] Figure 5 is the cross-sectional view of the sand control plate in the present invention;

[0030] Figure 6 is the cross-sectional view at the oxygen electrode stub in the present invention;

[0031] In the figure: 1 - oil pipe, 2 - hydrogen electrode stub, 3 - hydrogen electrode, 4 - fixing ring, 5 - foam generator, 6 - oxygen electrode, 7 - oxygen electrode stub, 8 - oxygen discharge pipe, 9 - casing, 10 - liquid accumulation layer, 11 - perforated layer, 12 - separation sleeve, 13 - gas-liquid separator, 41 - air guide hole, 51 - separation cylinder, 52 - throttle cover, 53 - throttle hole, 54 - sand control plate, 541 - sand control hole, 542 - atomization sheet, 543 - sand control cover, 544 - atomization power supply. Specific Embodiments

[0032] The present invention will be further described in detail below in conjunction with the embodiments and the accompanying drawings.

[0033] To make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention.

[0034] Embodiment: Refer to Figure 1, An electrolysis-assisted gas drainage and production device, including a hydrogen electrode 3, a foamer 5, and an oxygen discharge pipe 8. Among them, the foamer 5 is detachably arranged inside the oil pipe 1 and above the liquid accumulation layer 10. The foamer 5 at least includes a throttle cover 52 that can completely divide the oil pipe 1 into upper and lower parts. A plurality of groups of throttle holes 53 are vertically arranged on the throttle cover 52, allowing the gas entering the oil pipe 1 to pass through the throttle cover 52 from bottom to top. In actual production, the formation produced water accumulates at the bottom of the well to form a liquid accumulation layer 10, covering the perforation layer 11 of the produced natural gas. In the prior art, usually, a foaming agent is injected into the annulus of the oil pipe 1. The natural gas produced by the perforation layer 11 agitates in the liquid accumulation layer 10 with the added foaming agent to generate foam, and is carried by the natural gas flow to rise along the oil pipe 1 to the ground. Therefore, in this embodiment, after the natural gas carries the foam to the throttle cover 52 with a porous structure, the liquid accumulated in the foam can generate more stable foam in the throttle holes 53, thus effectively improving the carrying efficiency of the natural gas for the foam.

[0035] In this embodiment, the foamer 5 includes a separation cylinder 51 and a throttle cover 52. From Figure 3 , Figure 4 , it can be seen that the throttle cover 52 is a dome-shaped structure with an upward arc surface. It is detachably arranged inside the oil pipe 1, completely dividing the oil pipe 1 into upper and lower parts. A plurality of groups of throttle holes 53 are vertically arranged on its dome part to connect the upper and lower parts separated by the throttle cover 52. The separation cylinder 51 is detachably arranged coaxially inside the oil pipe 1, and the parts where it contacts the throttle cover 52 and the oil pipe 1 are connected. Refer to Figure 5 , a sand prevention plate 54 that horizontally divides the separation cylinder 51 into upper and lower parts is also arranged inside the separation cylinder 51. Among them, a plurality of groups of sand prevention holes 541 are vertically arranged on the sand prevention plate 54 for connecting the upper and lower surfaces of the sand prevention plate 54. Sand prevention covers 543 are correspondingly arranged below the sand prevention holes 541. The sand prevention cover 543 is a vertical pipe body with a continuously decreasing diameter from top to bottom, and its uppermost end is connected with the sand prevention hole 541 with the same diameter;

[0036] An atomizing power source 544 and a plurality of atomizing sheets 542 are provided on the upper surface of the sand-proof plate 54. The atomizing sheets 542 are arranged one by one above the sand-proof holes 541, and the atomizing holes on the atomizing sheets 542 are all connected to the sand-proof holes 541. It can be seen that a group of sand-proof plates 54 are actually provided below the throttling cover 52. Since the accumulated liquid layer also contains a large amount of sand particles, when the natural gas carries the foam upward, the foam surface will carry a certain amount of sand particles in addition to the accumulated liquid. These sand particles may block the throttling holes 53 widely present on the foamer 5 when passing through the foamer 5. Therefore, a sand-proof plate 54 with an atomizing sheet 542 is used to reduce and control the amount of sand particles entering the foamer 5. Among them, the sand-proof cover 543 is a positive funnel-shaped structure. To ensure the effect, the reduced diameter portion at the bottom can reduce the possibility of sand particles entering the sand-proof holes 541. On the one hand, it can generate swirling turbulence outside the sand control cover 543, disturbing the flow direction of the gas-liquid flow at the bottom of the sand control cover 543, so that most of the sand particles carried in the gas-liquid flow escape from the gas-liquid flow, effectively reducing the amount of sand carried in the fluid, and the atomizing holes on the atomizing sheet 542 are all connected with the sand control hole 541. The basic structure of the atomizing sheet 542 is a vibrating sheet with an atomizing hole, and its vibration energy is provided by the atomizing power supply 544. When the fluid passes through the atomizing hole, the vibration generated by it breaks up the fluid into smaller droplets, thereby producing an atomization effect. Therefore, when the atomizing hole of the atomizing sheet 542 in this embodiment is connected with the sand control hole 541, the liquid in the gas-liquid flow entering the sand control hole 541 can pass through the atomizing hole smoothly, while a small amount of solid as sand particles is difficult to pass through the atomizing hole, thereby achieving full removal of sand particles in the gas-liquid flow.

[0037] The hydrogen electrode 3 and the oxygen electrode 6 constitute the electrolysis auxiliary part of the present invention, which is composed of Figure 1 As shown, the hydrogen electrode 3 is detachably arranged in the hydrogen electrode short section 2 and connected to the ground through a cable. The hydrogen electrode short section 2 has the same diameter as the oil pipe 1 and is detachably arranged at the bottom of the oil pipe 1. Figure 2 A fixing ring 4 capable of completely separating the hydrogen electrode short section 2 is detachably provided inside the fixing ring 4, and a plurality of gas guide holes 41 are provided through the fixing ring 4 to allow gas to pass through the fixing ring 4. The hydrogen electrode 3 is provided through the fixing ring 4 and is immersed as a whole at a position where the bottom hole liquid accumulation layer 10 is higher than the perforation layer 11.

[0038] See also Figure 1, corresponding to the hydrogen electrode 3, the present invention uses the oxygen electrode 6 as the anode of electrolysis, and the oxygen discharge pipe 8 where the oxygen electrode 6 is located extends vertically into the wellbore and is immersed in the liquid accumulation layer 10. It can be directly arranged in the annulus. In some well groups developed with dual tubing, the oxygen discharge pipe 8 can also be arranged inside another group of tubing 1 outside the tubing 1 where the hydrogen electrode 3 is located, facilitating gas discharge. The bottom of the oxygen discharge pipe 8 is also detachably provided with an enlarged oxygen electrode short joint 7 immersed in the liquid accumulation layer 10, and the oxygen electrode 6 is arranged in the oxygen electrode short joint 7. Similar to the hydrogen electrode short joint 2, a fixing ring 4 is also detachably arranged inside the oxygen electrode short joint 7. The oxygen electrode 6 is arranged through the center of the fixing ring 4 and is connected to the ground through a cable inside the oxygen discharge pipe 8.

[0039] As Figure 6 shown, a cylindrical separation sleeve 12 is detachably sleeved on the oxygen electrode short joint 7. The top through hole of the separation sleeve 12 is sleeved on the outer surface of the oxygen electrode short joint 7, so that the inside of the oxygen discharge pipe 8 is communicated with the inside of the separation sleeve 12. A gas-liquid separator 13 that only allows liquid to enter the inside of the separation sleeve 12 and discharges gas to the outside of the separation sleeve 12 is arranged at the bottom of the separation sleeve 12. Such as the gas anchor used in the prior art. In such a structure, the liquid in the bottom hole liquid accumulation can pass through the gas-liquid separator 13 and enter the inside of the separation sleeve 12 to contact the oxygen electrode 6, and is electrolyzed by the oxygen electrode 6 to generate oxygen, which is discharged to the ground along the oxygen discharge pipe 8. However, gases such as natural gas and hydrogen that may be carried in the liquid accumulation cannot pass through the gas-liquid separator 13 and can only be sent to the ground along the tubing 1. In this way, it is ensured that the oxygen generated by the oxygen electrode 6 will not contact the gas, and the explosion risk that may be caused by gas mixing is reduced as much as possible. Among them, the depth of the oxygen electrode 6 and the oxygen electrode short joint 7 below the bottom hole liquid level can also be arbitrarily determined according to actual needs, not limited to only the liquid accumulation layer 10 or the perforation layer 11.

[0040] During construction, the hydrogen electrode 3 will be energized as the cathode, and the oxygen electrode 6 will be energized as the anode. The oxygen generated by the electrolysis of the anode has a density less than that of water and can be automatically discharged to the ground along the oxygen discharge pipe 8 under the action of water seal. Oxygen is generated at the oxygen electrode 6, and hydrogen is generated at the cathode. The water in the bottom hole liquid accumulation layer 10 is electrolyzed. The hydrogen obtained after the electrolysis of the cathode will be mixed with the produced natural gas in the formation to supplement the energy of the natural gas. At the same time, this process also consumes the liquid accumulation, achieving the function of supplementing energy for the foam-carrying gas on the one hand and reducing the total amount of liquid accumulation on the other hand.

[0041] In addition, in some embodiments, the diameter of the part of the oxygen discharge pipe 8 below the oxygen electrode 6 is larger than the part above the oxygen electrode 6, that is, as Figure 1 shown, the lower part is larger and the upper part is smaller. On the one hand, this can save the material for making the oxygen discharge pipe 8, reduce the space it occupies in the annulus, and reduce the construction difficulty of arranging the oxygen discharge pipe 8. On the other hand, the relatively thin upper part of the oxygen discharge pipe 8 can also produce a certain capillary effect, facilitating the conduction of the oxygen-formed bubbles to the ground.

[0042] Further, a method for electrolysis-assisted gas drainage and production based on the above-mentioned device for electrolysis-assisted gas drainage and production mainly includes the following steps:

[0043] Step S1: Arrange an oxygen discharge pipe immersed in the bottom-hole liquid accumulation layer in the wellbore according to the device structure. An oxygen electrode immersed in the bottom-hole liquid accumulation layer and connected to the ground is arranged inside the oxygen discharge pipe. A foamer and a hydrogen electrode connected to the ground are sequentially arranged in the tubing from top to bottom, wherein the hydrogen electrode is immersed in the liquid accumulation layer and above the perforation layer;

[0044] Step S2: Supply power to the hydrogen electrode and the oxygen electrode to form an electrolysis circuit to electrolyze the liquid accumulation layer, so that the gas generated at the oxygen electrode is discharged from the wellbore along the oxygen discharge pipe, and the gas generated at the hydrogen electrode enters the tubing together with the produced gas, passes through the foamer, and then is produced.

[0045] There is a risk of explosion when the oxygen generated by electrolysis is mixed with hydrogen and natural gas. To eliminate such risks, in some embodiments, the oxygen discharge pipe can be connected to a negative pressure source on the ground, and the negative pressure source directly pumps the oxygen generated by electrolysis to the ground to improve the oxygen discharge efficiency.

[0046] The position of the hydrogen electrode is higher than the perforation layer. Since the densities of natural gas and hydrogen are both less than that of water, the hydrogen generated by electrolysis of the hydrogen electrode can mix with the natural gas produced in the fracture layer along the trend, which not only supplements the energy of the natural gas but also decomposes and reduces the liquid accumulation, improving the foam generation efficiency while reducing the total liquid volume and comprehensively improving the efficiency of gas drainage and production.

[0047] In addition, during the electrolysis process, the formation liquid accumulation usually contains a certain amount of salts, and their anionic groups are mostly chloride ions. Therefore, a small amount of chlorine gas is extremely likely to be generated during the electrolysis of the oxygen electrode. Further, the oxygen discharge pipe is connected to a chlorine separation device on the ground to separate the small amount of chlorine gas mixed in the oxygen generated in the oxygen discharge pipe.

[0048] Among them, the electrolysis voltage and current can be selected according to the characteristics of the bottom-hole liquid accumulation, the wellbore pressure and temperature conditions, so as to achieve precise control of the electrolysis process, avoid excessive gas generation and affect the normal drainage and production process. For the selection of anode and cathode materials, materials commonly used in the art with corrosion resistance and good electrical conductivity can be selected to ensure that the electrolysis efficiency is not affected during long-term operation.

[0049] In summary, the present invention combines the physical characteristics of water seal and gas density. The designed anode pipeline can ensure that oxygen will not mix with other gases in the wellbore when discharged from the anode, and the hydrogen generated at the cathode is used to supplement the production energy and generate foam. On the basis of ensuring the safe separation of gases, the efficiency of bottom-hole liquid drainage is effectively improved. This solution conforms to the natural law of gas flow and can enhance the ability of gas wells to produce gas continuously and efficiently.

[0050] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and should not be construed as a limitation to the present invention.

[0051] As mentioned above, the above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in the embodiments of the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. An electrolysis-assisted gas drainage and production device, characterized in that It includes a hydrogen electrode (3), a foamer (5), and an oxygen discharge pipe (8). Among them, the foamer (5) is detachably arranged inside the oil pipe (1) and above the liquid accumulation layer (10) at the bottom of the well. The foamer (5) at least includes a throttle cover (52) that can completely divide the oil pipe (1) into upper and lower parts. A plurality of groups of throttle holes (53) are vertically arranged on the throttle cover (52), which can allow the gas entering the oil pipe (1) to pass through the throttle cover (52) from bottom to top; The hydrogen electrode (3) is detachably arranged in the hydrogen electrode nipple (2). The hydrogen electrode nipple (2) has the same diameter as the oil pipe (1). The hydrogen electrode nipple (2) is detachably arranged at the bottom of the oil pipe (1), and the hydrogen electrode (3) is immersed in the liquid accumulation layer (10), and the position of the hydrogen electrode (3) is higher than the perforation layer (11); The oxygen discharge pipe (8) connected to the ground extends vertically into the well and is immersed in the liquid accumulation layer (10). Among them, an oxygen electrode nipple (7) with an enlarged diameter is detachably arranged at the bottom of the oxygen discharge pipe (8) and immersed in the liquid accumulation layer (10). A cylindrical separation sleeve (12) is detachably sleeved at the bottom of the oxygen electrode nipple (7). The top through hole of the separation sleeve (12) is sleeved on the outer surface of the oxygen electrode nipple (7), so that the inside of the oxygen discharge pipe (8) is communicated with the inside of the separation sleeve (12). A gas-liquid separator (13) that only allows liquid to enter the inside of the separation sleeve (12) is arranged at the bottom of the separation sleeve (12). The oxygen electrode (6) is arranged in the oxygen electrode nipple (7) and immersed in the liquid accumulation layer (10). The hydrogen electrode (3) and the oxygen electrode (6) can be connected to an external power supply to form an electrolytic circuit. Among them, the hydrogen electrode (3) is the cathode and the oxygen electrode (6) is the anode; The foamer (5) includes a separation cylinder (51) and a throttle cover (52). Among them, the throttle cover (52) is a dome-shaped structure with an upward arc surface. The throttle cover (52) is detachably arranged inside the oil pipe (1) and completely divides the oil pipe (1) into upper and lower parts. A plurality of groups of throttle holes (53) are vertically arranged on the dome part of the throttle cover (52) to communicate the upper and lower parts separated by the throttle cover (52); The separation cylinder (51) is detachably coaxially arranged on the inner surface of the oil pipe (1) and is connected to the edge of the throttle cover (52). A sand prevention plate (54) that completely divides the separation cylinder (51) into upper and lower parts is horizontally arranged inside the separation cylinder (51). Among them, a plurality of groups of sand prevention holes (541) are vertically penetrated through the sand prevention plate (54). Sand prevention covers (543) are correspondingly arranged below the sand prevention holes (541). The sand prevention cover (543) is a vertical pipe body that continuously reduces in diameter from top to bottom, and the uppermost end of the sand prevention cover (543) is connected with the same diameter as the sand prevention hole (541); An atomization power supply (544) and a plurality of groups of atomization sheets (542) are arranged on the upper surface of the sand prevention plate (54). The atomization sheets (542) are correspondingly arranged above the sand prevention holes (541), and the atomization holes on the atomization sheets (542) are all communicated with the sand prevention holes (541).

2. The electrolysis-assisted gas drainage and production device according to claim 1, wherein: A fixing ring (4) is detachably arranged inside the hydrogen electrode nipple (2). The fixing ring (4) can completely divide the inside of the hydrogen electrode nipple (2) into upper and lower parts. Among them, a plurality of air guide holes (41) communicating the upper and lower parts are arranged on the fixing ring (4). The hydrogen electrode (3) is arranged through the center of the fixing ring (4) and is connected to the ground through a cable.

3. The electrolysis-assisted gas drainage and production device according to claim 2, wherein: The fixing ring (4) is made of insulating ceramic material and is fixed inside the hydrogen electrode nipple (2) by means of threaded connection.

4. The electrolysis-assisted gas drainage and production device according to claim 2, wherein: A fixing ring (4) is also detachably arranged inside the oxygen electrode nipple (7). The oxygen electrode (6) is arranged through the center of the fixing ring (4) and is connected to the ground through a cable.

5. An electrolysis-assisted gas drainage and production method, characterized in that, Using the device described in any one of claims 1-4 for drainage gas production, comprising the following steps: Step S1: Arrange an oxygen discharge pipe immersed in the bottom-hole liquid accumulation layer in the wellbore according to the device structure. An oxygen electrode immersed in the bottom-hole liquid accumulation layer and connected to the ground is arranged inside the oxygen discharge pipe. A foam generator and a hydrogen electrode connected to the ground are sequentially arranged from top to bottom in the tubing string. Among them, the hydrogen electrode is immersed in the liquid accumulation layer and is located above the perforation layer. Step S2: Supply power to the hydrogen electrode and the oxygen electrode to form an electrolytic circuit to electrolyze the liquid accumulation layer, so that the gas generated at the oxygen electrode is discharged from the wellbore along the oxygen discharge pipe, and the gas generated at the hydrogen electrode enters the tubing string together with the produced gas, passes through the foam generator and is then produced.

6. The electrolysis-assisted gas drainage and production method according to claim 5, wherein: The oxygen discharge pipe (8) is connected to a negative pressure source on the ground.

7. The electrolysis-assisted gas drainage and production method according to claim 5, wherein: The oxygen discharge pipe (8) is connected to a chlorine separation device on the ground.

Images