Composite drainage gas recovery device and method

Abstract

The invention belongs to the technical field of downhole tools of natural gas wells, and particularly discloses a composite drainage gas recovery device and method. Comprising a shell, a power generation device and a kinetic energy device are sequentially arranged in the shell in the axis direction, a heat energy device is arranged between the kinetic energy device and the shell, and the heat energy device is electrically connected with the power generation device. During working, the gas inlet of the shell (1) is connected with the gas outlet of a drainage gas recovery downhole device; the mixed liquid flows through the power generation device (2), and the power generation device (2) generates power and supplies electric energy to the heat energy device (4); the kinetic energy device (3) is used for increasing the pressure of mixed liquid and gas, meanwhile, the heat energy device (4) heats the kinetic energy device (3) to further increase the pressure, and meanwhile solid paraffin on the outer side of the kinetic energy device is subjected to hot melting. The exhaust efficiency is improved by increasing pressure in the kinetic energy device and accelerating gas flow, and meanwhile the exhaust efficiency is improved by arranging the heat energy device on the outer side of the kinetic energy device to melt solid paraffin.

Description

Technical Field

[0001] The present invention belongs to the technical field of downhole tools for natural gas wells, and particularly relates to a composite drainage gas production device and method. Background Art

[0002] During the process of natural gas exploitation, as the productivity of the gas well and the formation pressure decrease and the edge and bottom water coning occurs, formation water will enter the wellbore. When the flow rate of natural gas is insufficient to carry the liquid, liquid accumulation will occur in the gas well. Once liquid accumulates in the gas well, it will seriously affect the production of the gas well and even lead to the phenomenon of water flooding and blowout stopping. Liquid accumulation in gas wells is a common problem faced in the middle and late stages of the exploitation of water-bearing gas reservoirs. How to efficiently drain the liquid accumulated in the wellbore is the key to solving the problem of liquid-accumulated gas wells.

[0003] Vortex drainage gas production is a current advanced technology for solving liquid accumulation in gas wells. When gas and liquid enter the vortex tool, the flow rate of gas and liquid will be accelerated, thereby achieving the purpose of drainage gas production. The existing internal vortex design of drainage gas production tools can solve the problem of liquid carrying in the low flow rate area of the jet flow, effectively prevent the back pressure at the outlet of the jet nozzle from rising due to liquid accumulation above the jet generator and affecting the normal production of the gas well. The drainage gas production tool that combines throttling and vortex has greatly improved the efficiency of drainage gas production.

[0004] However, the existing drainage gas production tools still have the following problems: (1) There is a serious problem with the diversion groove of the existing drainage gas production tools. The existence of the vortex direction reduces the effective distance of the gas-liquid mixed fluid flowing in the vertical direction; (2) The flow channel size of the traditional vortex tool is fixed, which reduces the adaptability of the vortex tool in the field. Under different gas production rates, liquid production rates and pressure conditions, the required inner diameter of the flow channel varies greatly, and the fixed flow is obviously unreasonable; (1) For natural gas reservoirs, due to the change of the flow channel, the addition of the vortex tool increases the possibility of the formation of natural gas hydrates or wax deposition in high-wax gas reservoirs, especially more likely to form at the vortex tool. (4) For gas wells with serious liquid accumulation, the single vortex drainage gas production process technology has low efficiency. The foam drainage gas production process technology is another method for solving liquid accumulation in gas wells. How to combine the foam drainage gas production technology with the vortex drainage gas production process technology is still a difficult problem faced by gas wells with serious liquid accumulation.

[0005] In view of this, it is necessary to provide an adjustable and self-heating composite drainage gas production tool to solve the problems involved in the above background art. Summary of the Invention

[0006] The purpose of the present invention is to provide a composite drainage gas production device and method to solve the technical problem that natural gas hydrates or wax deposition in high-wax gas reservoirs are likely to occur in the existing drainage gas production device, especially more likely to form at the vortex tool, resulting in low drainage gas production efficiency.

[0007] To achieve the above object, the present invention is implemented by the following technical solutions:

[0008] In a first aspect, the present invention provides a composite drainage gas production device, including a housing. Inside the housing, a power generation device and a kinetic energy device are sequentially arranged along the axial direction. A heat energy device is arranged between the kinetic energy device and the housing, and the heat energy device is electrically connected to the power generation device.

[0009] A further improvement of the present invention is that the kinetic energy device includes a series of vortex fan groups. The output end of the vortex fan group is fixedly connected to a planetary reducer, the planetary reducer is rotationally connected to a core shaft, and a pressurization mechanism is arranged on the core shaft.

[0010] A further improvement of the present invention is that a Tesla flow guide cone is sleeved outside the planetary reducer. The outer diameter of the end of the Tesla flow guide cone far from the planetary reducer is larger than that of the end close to the planetary reducer, and the inner diameter of the end of the Tesla flow guide cone far from the planetary reducer is smaller than that of the end close to the planetary reducer.

[0011] A further improvement of the present invention is that a first reinforcing rib is arranged between the vortex fan group and the power generation device, and a second reinforcing rib is arranged between the vortex fan group and the Tesla flow guide cone.

[0012] A further improvement of the present invention is that the pressurization mechanism includes a number of expansion structures. Each expansion structure includes an annular skeleton structure, a main displacement member and a slave fixing member. One end of the annular skeleton structure is fixedly connected to the main displacement member, and the other end of the annular skeleton structure is fixedly connected to the slave fixing member. Both the main displacement member and the slave fixing member are sleeved on the core shaft.

[0013] A further improvement of the present invention is that both the main displacement member and the slave fixing member are threadedly connected to the core shaft.

[0014] A further improvement of the present invention is that the slave fixing member is fixed on the core shaft, and an elastic member is arranged between the main displacement member and the slave fixing member.

[0015] A further improvement of the present invention is that the heating device is an electric heating cylinder, and the electric heating cylinder is arranged outside the pressurization device.

[0016] A further improvement of the present invention is that the annular skeleton structures are all fixedly connected to the electric heating cylinder through fixed grids and are all slidably connected to the electric heating cylinder through movable grids.

[0017] In a second aspect, the present invention provides a method for using a composite drainage gas production device, including the following steps:

[0018] Connect the air inlet of the housing to the air outlet of the downhole device for drainage gas production;

[0019] The mixture gas flow passes through the power generation device, which generates electricity and supplies the electrical energy to the heat energy device;

[0020] The kinetic energy device is used to increase the pressure of the mixture gas, and at the same time, the heat energy device heats the kinetic energy device to further increase the pressure and melt the solid paraffin on the outside of the kinetic energy device.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] 1. In the present invention, the pressure is increased in the kinetic energy device to accelerate the gas flow and improve the exhaust efficiency. At the same time, a heat energy device is arranged outside the kinetic energy device to melt the solid paraffin to improve the exhaust efficiency;

[0023] 2. In the present invention, the turbine group converts the flowing energy into mechanical energy. On the one hand, during the rotation of the turbine, it helps to form low-density foam, promotes gas-liquid mixing and improves the recovery rate; on the other hand, the turbine rotation provides guarantee for the overall operation of the tool.

[0024] 3. The present invention adopts a straight-through flow channel, the width of the channel gradually decreases, and the depth of the channel changes periodically, which reduces the deposition of high-viscosity substances and improves the use effect of the existing drainage gas production process.

[0025] 4. The present invention adopts a self-heating system. The fluid drives the power generation device to rotate to increase the temperature inside the tool, avoiding the solidification of wax-containing substances inside the tool cavity in a low-temperature environment and increasing the service life of the tool.

[0026] 5. The eddy current groove of the eddy current drainage gas production tool is changed into a tapered direct current groove, which greatly improves the effective flow distance of gas and liquid in the vertical direction. In the traditional eddy current tool, the gas-liquid flow moves upward in the form of a rotating eddy current, resulting in a smaller effective distance and a poor eddy current effect. However, this improvement can greatly increase the effective distance of gas and liquid, thereby increasing the drainage gas production effect.

[0027] 6. The present invention patent sets an automatic heating device, which uses the energy of the gas well itself to drive the heating device, so that the whole eddy current tool is in a heating state, avoiding the production of hydrates or wax deposition, and increasing the drainage gas production effect.

[0028] 7. The inlet end is provided with fan blades and a vortex fan group. The presence of the fan blades and the vortex fan group will increase the implementation effect of the eddy current drainage gas production process technology and the foam drainage gas production process technology. The rotation of the fan blades and the vortex fan group will increase the bubble effect of the foam drainage agent, thereby reducing the fluid mixing density, increasing the flow distance, and improving the drainage gas production effect.

[0029] 8. The flow channel size of traditional eddy current tools is fixed, which reduces the adaptability of eddy current tools in the field. Under different gas production rates, liquid production rates, and pressure conditions, the required inner diameter of the flow channel varies greatly. Fixed flow is obviously unreasonable. The design of the annular skeleton structure will cause the movable grid to expand and contract periodically, thereby changing the flow channel size. The greater the gas-liquid flow velocity, the higher the frequency of expansion and contraction, increasing the effect of gas drainage and production.

[0030] 9. This tool can be applied to highly deviated wells. The existence of the eddy current groove in traditional eddy current tools will cause the flowing liquid to move forward in the form of eddy currents. In highly deviated wells, due to the existence of the gravity component, the effective gas-liquid flow distance will be reduced. The improved tapered straight flow groove of this tool can avoid this problem. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The attached drawings forming a part of this invention are used to provide a further understanding of the invention. The schematic embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0032] In the drawings:

[0033] Figure 1 is a schematic diagram of the downhole of a composite gas drainage and production device provided by the present invention;

[0034] Figure 2 is a schematic diagram at the air inlet of a composite gas drainage and production device provided by the present invention;

[0035] Figure 3 is a schematic diagram of the overall structure of a composite gas drainage and production device provided by the present invention;

[0036] Figure 4 is a schematic diagram of the internal structure of a composite gas drainage and production device provided by the present invention;

[0037] Figure 5 is a side sectional view of a composite gas drainage and production device provided by the present invention;

[0038] Figure 6 is a partial sectional view of the electric energy device and part of the kinetic energy device in a composite gas drainage and production device provided by the present invention;

[0039] Figure 7 is a schematic diagram of the annular skeleton structure in a composite gas drainage and production device provided by the present invention;

[0040] Figure 8 is a sectional view of the Tesla current conductor in a composite gas drainage and production device provided by the present invention;

[0041] Figure 9Schematic diagram of the main displacement member and the secondary fixing member in a composite drainage and gas production device provided by the present invention.

[0042] In the figure: housing 1, wedge-shaped guide surface 11, annular clamping groove 12, wedge-shaped protrusion 13, power generation device 2, wire 21, first reinforcing rib 22, power device 3, vortex fan group 31, planetary reducer 32, core shaft 33, pressurization mechanism 34, annular skeleton structure 341, main displacement member 342, secondary fixing member 343, elastic member 344, heat energy device 4, Tesla flow guide cone 5, second reinforcing rib 51, fishing head 6, sliding member 61, fishing connection member 62, elastic clamping member 7. Specific embodiments

[0043] The present invention will be described in detail below with reference to the drawings and in conjunction with embodiments. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0044] The following detailed descriptions are all exemplary descriptions, aiming to provide further detailed descriptions of the present invention. Unless otherwise specified, all technical terms used in the present invention have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs. The terms used in the present invention are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present invention.

[0045] Embodiment 1

[0046] A composite drainage and gas production device, as Figures 1 to 9 shown, includes a housing 1 and a fishing head 6. One end of the housing 1 is axially connected to the fishing head 6. The bottom circumference of the other end of the housing 1 is provided with a wedge-shaped guide surface 11. Above the wedge-shaped guide surface 11, an annular clamping groove 12 is opened on the housing 1. The outer diameter of the annular clamping groove 12 is smaller than the outer diameter of the wedge-shaped guide surface 11. A plurality of wedge-shaped protrusions 13 are evenly arranged between the wedge-shaped guide surface 11 and the annular clamping groove 12. Inside the housing 1, a power generation device 2 and a power device 3 are sequentially arranged along the axis from the end far away from the fishing head 6. A plurality of heat energy devices 4 are evenly arranged between the power device 3 and the housing 1. The heat energy device 4 is electrically connected to the power generation device 2.

[0047] Specifically, the power generation device 2 is an impeller generator. When gas and liquid pass through the power generation device 2, the impeller is driven to rotate, thereby generating electricity. The power generation device 2 supplies power to the heat energy device 4 through the wire 21.

[0048] Specifically, the kinetic energy device 3 includes a fan group 31, a planetary reducer 32, a core shaft 33, and a pressurizing mechanism 34. One end of the planetary reducer 32 is fixedly connected to the fan group 31, and the other end of the planetary reducer 32 is rotatably connected to the core shaft 33. A pressurizing mechanism 34 is sleeved on the core shaft 33. The flowing natural gas drives the planetary reducer 32 to rotate through the fan group 31. The core shaft 33 is connected to the output end of the planetary reducer 32 and extends into the pressurizing mechanism 34. The core shaft 33 is driven by the planetary reducer 32 to cause the pressurizing mechanism 34 to expand and contract to increase the flow rate of the natural gas.

[0049] Specifically, a Tesla flow guiding cone 5 is sleeved outside the planetary reducer 32. The outer diameter of the Tesla flow guiding cone 5 at the end close to the fishing head 6 is larger than the outer diameter at the end close to the power generation device 2, and the inner diameter of the Tesla flow guiding cone 5 at the end close to the fishing head 6 is smaller than the inner diameter at the end close to the power generation device 2. The inner diameter of the Tesla flow guiding cone 5 is larger than the outer diameter of the core shaft 33. The Tesla flow guiding cone 5 is arranged in a streamline shape in the direction of the vortex fan towards the expansion structure 345, so that the foamy gas-liquid mixture generated by the vortex fan is more likely to flow into the space between the electrothermal element and the pressurizing mechanism 34. And an annular one-way flow channel is formed between the end of the Tesla flow guiding cone 5 connected to the expansion structure 345 and the expansion structure 345, so that the foamy gas-liquid mixture passes through the one-way flow channel to achieve the one-way guiding effect.

[0050] Specifically, a first reinforcing rib 22 is provided between the fan group 31 and the power generation device 2, and a second reinforcing rib 51 is provided between the fan group 31 and the Tesla flow guiding cone 5.

[0051] Specifically, a first hole is opened in the first reinforcing rib 22, a second hole is opened in the second reinforcing rib 51, and a through hole is opened in the outer shell 1 between the first hole and the second hole. The wire 21 passes through the through hole to protect the wire 21.

[0052] Specifically, the pressurizing structure 34 includes a plurality of expansion structures. A plurality of expansion structures are sleeved on the core shaft 33. Each expansion structure includes an annular skeleton structure 341, a main displacement member 342, a slave fixing member 343, and an elastic member 344. The main displacement member 342 is slidably sleeved on the core shaft 33, the slave fixing member 343 is fixedly sleeved on the core shaft 33, the annular skeleton structure 341 is a folding structure, one end of the annular skeleton structure 341 is fixed to the slave fixing member 343, the other end of the annular skeleton structure 341 is fixed to the main displacement member 342, and an elastic member 344 is provided between the main displacement member 342 and the slave fixing member 343.

[0053] Specifically, the heating device 2 is an electric heating cylinder, which is cylindrical in shape, and its outer peripheral wall is embedded in the inner wall of the outer shell 1, and the inner wall of the heating device 2 is sleeved outside the pressurizing device 34.

[0054] Specifically, the pressurization structure 34 further includes a fixed grid and a movable grid. Each annular skeleton structure 341 is fixedly connected to the electric heating cylinder through the fixed grid, and each annular skeleton structure 341 is slidably connected to the electric heating cylinder through the movable grid. When the annular skeleton structure 341 expands and contracts periodically, its movable grid tightly abuts against the inner wall of the electric heating cylinder, and a seal is formed between the fixed grid, the movable grid, the annular skeleton structure 341 and the electric heating cylinder. When the annular skeleton structure 341 is in a contracted state, the movable grid is away from the inner wall of the electric heating cylinder. At this time, an expansion channel is formed between the pressurization mechanism 34 and the electric heating cylinder. Through the relaxation of the pressurization mechanism 34 itself, the foamy gas-liquid mixture fully mixed in the fan group 31 is pressurized to increase the flow rate of the fluid.

[0055] Specifically, one end of the outer shell 1 away from the fishing head 6 is connected to the gas outlet of the downhole device for drainage gas production by thread connection or clamping. When the gas-liquid inlet of the adjustable and self-heating composite drainage gas production tool is thread-connected to the downhole device for drainage gas production, an internal thread or external thread for thread connection with the downhole device for drainage gas production can be provided at the gas-liquid inlet of the adjustable and self-heating composite drainage gas production tool. However, considering that when using thread connection, when it is necessary to replace the adjustable and self-heating composite drainage gas production tool of different models, the existing downhole device for drainage gas production needs to be taken out of the deep well and then thread-connected, and the replacement process is particularly complicated.

[0056] Specifically, the outer shell 1 is arranged in the gas outlet pipe of the downhole device for drainage gas production. A groove is provided on the outer wall of the gas outlet pipe, and an elastic clamping member 7 is arranged in the groove. The elastic clamping member 7 cooperates with the wedge-shaped convex block 13 to fixedly connect the outer shell 1 to the gas outlet pipe.

[0057] Specifically, the mutual separation and approach between the main displacement member 342 and the slave fixing member 343 can be driven by setting two threads in opposite directions, or by moving one end and then rebounding through the elastic member 344 to achieve periodic mutual separation and approach.

[0058] Specifically, in the process of realizing the mutual separation between the main displacement member 342 and the slave fixing member 343, the core shaft 33 is subjected to the rotational torque force of the planetary reducer 32. Through the rotation of the core shaft 33, the outer wall of the core shaft 33 drives the slave fixing member 343 to rotate, so that the main displacement member 342 spirally rotates away from the outer ring. At this time, the elastic member 344 is in a stretched state.

[0059] Since the main displacement member 342 and the slave fixing member 343 reciprocate axially periodically, the annular skeleton structure 341 expands and contracts periodically, thereby pressurizing the natural gas passing through the power device 3 to increase the flow rate of the natural gas.

[0060] Specifically, the fishing head 6 includes a sliding member 61 and a fishing connection member 62 coaxially connected to the sliding member 61. One end of the core shaft 33 away from the planetary reducer 32 slides axially along the sliding member 61 and is rotatably connected. The fishing connection member 62 is fixedly connected to the inner wall of the housing 1. When the core shaft 33 is rotating, while the core shaft 33 rotates itself, it also makes a periodic reciprocating motion along the axial direction of the sliding member 61. In addition, the fishing connection member 62 is used to connect with a fishing tool, so as to achieve the effect of replacing the adjustable and self-heating composite drainage gas production tool by fixedly connecting with the gas outlet end of the housing 1.

[0061] Embodiment 2

[0062] A method for using a composite drainage gas production device includes the following steps:

[0063] Connect the air inlet of the housing 1 to the gas outlet of the drainage gas production downhole device;

[0064] The mixed liquid gas flows through the power generation device 2, and the power generation device 2 generates electricity and supplies the electric energy to the heat energy device 4;

[0065] The kinetic energy device 3 is used to increase the pressure of the mixed liquid gas. At the same time, the heat energy device 4 heats the kinetic energy device 3 to further increase the pressure, and at the same time melts the solid paraffin on the outer side of the kinetic energy device.

[0066] When the gas-liquid passes through the vortex fan group 31 formed by multiple vortex fans, it provides power for the vortex fan group 31. On the one hand, the vortex fan group 31 fully mixes the gas-liquid to form a foamy gas-liquid mixture. On the other hand, the vortex fan group 31 drives the planetary reducer 32 to rotate, and the planetary reducer 32 provides a rotational torque for the core shaft 33. Through the rotation of the core shaft 33, the pressurizing mechanism 34 expands and contracts periodically, so that the adjustable and self-heating composite drainage gas production tool is automatically pressurized to increase the flow rate of the foamy gas-liquid mixture. At the same time, the heat energy device 4 that generates electricity by the power generation device 2 and is arranged around the power device 3 generates heat to melt the solid paraffin on the outer periphery of the power device 3, so as to effectively improve the drainage gas production effect in the coiled tubing during downhole operations and improve the natural gas production efficiency while ensuring the normal working state of the adjustable and self-heating composite drainage gas production tool.

[0067] As is known by technical common sense, the present invention can be implemented by other embodiments that do not depart from its spiritual essence or essential features. Therefore, the above-disclosed embodiments are illustrative in all aspects and are not the only ones. All changes within the scope of the present invention or within the scope equivalent to the present invention are included in the present invention.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications or equivalent substitutions can still be made to the specific embodiments of the present invention, and any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered by the protection scope of the claims of the present invention.

Claims

1. A composite drainage gas production device, characterized in that, It includes a housing (1), inside which there are successively arranged a power generation device (2) and a kinetic energy device (3) along the axial direction. There is a heat energy device (4) between the kinetic energy device (3) and the housing (1), and the heat energy device (4) is electrically connected to the power generation device (2).

2. The composite drainage gas production device according to claim 1, wherein, The kinetic energy device (3) includes a series of vortex fan groups (31) in sequence. The output end of the vortex fan group (31) is fixedly connected to a planetary reducer (32). The planetary reducer (32) is rotationally connected to a core shaft (33), and a pressurization mechanism (34) is provided on the core shaft (33).

3. The composite drainage gas production device according to claim 2, characterized in that, A Tesla flow guide cone (5) is sleeved outside the planetary reducer (32). The outer diameter of the end of the Tesla flow guide cone (5) far from the planetary reducer (32) is larger than that of the end close to the planetary reducer (32), and the inner diameter of the end of the Tesla flow guide cone (5) far from the planetary reducer (32) is smaller than that of the end close to the planetary reducer (32).

4. The composite drainage gas production device according to claim 3, characterized in that, There is a first reinforcing rib (22) between the vortex fan group (31) and the power generation device (2), and a second reinforcing rib (51) between the vortex fan group (31) and the Tesla flow guide cone (5).

5. The composite drainage gas production device according to claim 2, characterized in that, The pressurization mechanism (34) includes a number of expansion structures. Each expansion structure includes an annular skeleton structure (341), a main displacement member (342), and a slave fixing member (343). One end of the annular skeleton structure (341) is fixedly connected to the main displacement member (342), and the other end of the annular skeleton structure (341) is fixedly connected to the slave fixing member (343). Both the main displacement member (342) and the slave fixing member (343) are sleeved on the core shaft (33).

6. The composite drainage gas production device according to claim 5, wherein, Both the main displacement member (342) and the slave fixing member (343) are threadedly connected to the core shaft (33).

7. The composite drainage gas production device according to claim 5, wherein, The slave fixing member (343) is fixed on the core shaft (33), and an elastic member (344) is provided between the main displacement member (342) and the slave fixing member (343).

8. The composite drainage gas production device according to claim 5, characterized in that The heating device (2) is an electric heating cylinder, and the electric heating cylinder is arranged outside the pressurization device (34).

9. The composite drainage gas production device according to claim 8, wherein, Each annular skeleton structure (341) is fixedly connected to the electric heating cylinder through a fixed grid and is slidably connected to the electric heating cylinder through a movable grid.

10. A method for using a composite drainage gas production device, based on the composite drainage gas production device according to any one of claims 1 to 9, characterized in that, It includes the following steps: Connect the air inlet of the housing (1) to the gas outlet of the device under the drainage and gas production well; The mixed liquid gas flows through the power generation device (2), and the power generation device (2) generates electricity and supplies the electric energy to the heat energy device (4); The kinetic energy device (3) is used to increase the pressure of the mixed liquid gas. At the same time, the heat energy device (4) heats the kinetic energy device (3) to further increase the pressure and melt the solid paraffin outside the kinetic energy device at the same time.

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