Oil well heating system

Abstract

The utility model provides an oil well heating system. The oil well heating system comprises a steam boiler, a mixer and a hot water injection device which are sequentially connected in series. The steam boiler is connected with the softened water tank through a boiler feed pump; the steam boiler is further connected with an air blower and a fuel supply box. The mixer is also connected with a well bottom produced liquid storage device through a liquid transfer pump; a Y-shaped filter is further arranged between the liquid transfer pump and the well bottom produced liquid storage device; the hot water injection device is arranged in the oil well. According to the system, the oil well is heated by using the device, the defects that the steam consumption is large and the energy consumption is high due to the fact that steam is easy to escape in a steam heating mode are overcome, and the beneficial effects of being high in temperature rising speed and uniform in heating are further achieved due to the fact that hot water is adopted for heating due to the characteristic of liquidity of liquid.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of crude oil production, and particularly relates to an oil well heating system. BACKGROUND

[0002] In the process of producing crude oil in an oil well, it is necessary to ensure that the crude oil in the formation can flow into the wellbore in a radial direction, and the underground crude oil flowing into the bottom of the wellbore can be lifted to the ground. In the process of lifting the underground crude oil, it is a process of heat dissipation and temperature drop. Because the underground crude oil contains a large amount of temperature-sensitive components, such as paraffin in thick oil and high condensate oil. In the process of lifting the oil well, as the temperature gradient of the formation decreases, the heat of the oil in the well is seriously lost. The temperature of the surface layer of the oil near the ground is low, and the paraffin will be condensed. The paraffin condensation directly increases the difficulty of oil production, and the load of the production equipment increases. Serious plugging phenomenon may occur. In order to solve this problem, the crude oil in the oil well needs to be heated to improve the temperature of the crude oil, so as to achieve temperature compensation, thereby improving the flow performance of the crude oil, so as to facilitate the production of the crude oil.

[0003] The existing heating methods include steam heating and electric heating. Large oil fields usually use electric heating. Although electric heating has the advantages of high heating efficiency and low pollution, the electric heater applied to crude oil heating still has problems such as uneven heating, slow heating speed, and incomplete heating. In addition, electric heating requires a complete power supply system and is not suitable for small-scale oil field production. Therefore, in small-scale oil field production, traditional steam heating is still the main method. However, steam heating has the problems of easy escape of steam, large steam consumption, and high energy consumption. CONTENT OF THE INVENTION

[0004] The present application provides an oil well heating system to solve the problem of large steam consumption and high energy consumption caused by the easy escape of steam in the existing steam heating method for heating the oil well.

[0005] The present application provides an oil well heating system, which comprises a steam boiler, a mixer and a hot water injection device connected in series.

[0006] The steam boiler is connected with a softened water tank through a boiler feed water pump.

[0007] The steam boiler is further connected with a blower and a fuel supply tank.

[0008] The mixer is further connected with a well bottom produced liquid storage device through a liquid circulating pump.

[0009] A Y-shaped filter is further arranged between the liquid circulating pump and the well bottom produced liquid storage device.

[0010] The hot water injection device is arranged in the oil well.

[0011] Optionally, a buffer device is provided between the mixer and the hot water injection device.

[0012] Optionally, a temperature sensor is provided on the buffer device, and the temperature sensor is electrically connected to the controller;

[0013] The controller is also electrically connected to the blower and steam boiler.

[0014] Optionally, the transfer pump and the mixer are connected to the drain line via a three-way valve.

[0015] Optionally, the buffer device includes a buffer housing;

[0016] The buffer shell contains a liquid reservoir, and the space between the outer wall of the liquid reservoir and the buffer shell is filled with a buffer layer.

[0017] A connecting tube is provided on each of the two opposite side walls of the reservoir. The connecting tube passes through the buffer shell and extends out of the buffer shell. The part of the connecting tube between the reservoir and the buffer shell is a retractable flexible tube. The connecting tube is fixedly connected to the buffer shell.

[0018] Optionally, the reservoir is also covered with a restraint net.

[0019] Optionally, the mixer includes a housing;

[0020] A partition is provided inside the shell along the radial direction, with space left between the top and bottom of the partition and the shell;

[0021] A gas distribution pipe is provided in the lower part of the shell along the axial direction of the shell. The inlet end of the gas distribution pipe is connected to the steam boiler. The gas distribution pipe is located between the partition and the shell.

[0022] A liquid distribution plate is provided in the upper part of the housing near the inlet end of the air distribution pipe, and a liquid inlet is provided on the housing above the liquid distribution plate.

[0023] The bottom of the shell has a liquid outlet, and the upper part of the shell has a vent located away from the liquid inlet.

[0024] Optionally, an air guide chamber is provided between the top of the partition and the shell, and the air guide chamber is connected to an air distribution plate provided between the air guide chamber and the air distribution pipe through a conduit;

[0025] The air distribution plate is separated from the liquid distribution plate by a partition.

[0026] This application provides an oil well heating system. By setting up a mixer, steam produced by a steam boiler is mixed with produced fluid stored at the bottom of the well to form hot water with high temperature. The hot water is then introduced into a hot water injection device for injection into the oil well to heat the oil well. The system of this application heats the oil well by using the above-mentioned device, which overcomes the disadvantages of steam heating, such as easy steam escape, resulting in high steam consumption and high energy consumption. Moreover, due to the fluidity of the liquid, hot water heating also has the beneficial effects of fast heating speed and uniform heating. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of an oil well heating system provided in an embodiment of this application;

[0029] Figure 2 This is a schematic diagram of the structure of a buffer device provided in an embodiment of this application;

[0030] Figure 3 A schematic cross-sectional view of the liquid reservoir provided in an embodiment of this application;

[0031] Figure 4 This is a schematic diagram of the structure of a mixer provided in one embodiment of this application;

[0032] Figure 5 This is a schematic cross-sectional view of a mixer provided in an embodiment of this application.

[0033] Explanation of reference numerals in the attached figures:

[0034] 1. Steam boiler; 2. Mixer; 3. Hot water injection device; 4. Softened water tank; 5. Fuel supply tank; 6. Well bottom produced fluid storage device; 7. Buffer device; 8. Controller; 9. Sewage pipeline; 10. Boiler feed pump; 11. Blower; 20. Transfer pump; 21. Shell; 22. Baffle; 23. Air distribution pipe; 24. Liquid distribution plate; 25. Air guide chamber; 61. Y-shaped filter; 70. Temperature sensor; 71. Buffer shell; 72. Liquid storage bladder; 73. Buffer layer; 74. Restraint net; 100. Three-way valve; 201. Liquid inlet; 202. Liquid outlet; 203. Exhaust port; 251. Air distribution plate. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are also within the scope of protection of this application.

[0036] like Figure 1 As shown, this application provides an oil well heating system, including a steam boiler 1, a mixer 2, and a hot water injection device 3 connected in series.

[0037] Steam boiler 1 is connected to softened water tank 4 via boiler feed water pump 10;

[0038] The steam boiler 1 is also connected to the blower 11 and the fuel supply box 5 respectively;

[0039] The mixer 2 is also connected to the bottom-of-well produced fluid storage device 6 via a transfer pump 20;

[0040] A Y-shaped filter 61 is also installed between the transfer pump 20 and the bottom-hole produced fluid storage device 6;

[0041] The hot water injection device 3 is installed in the oil well.

[0042] In actual production, because the produced fluid at the bottom of the well contains ions that are prone to scaling or corrosion, the mixer 2 is also connected to a scale inhibitor and corrosion inhibitor storage tank. Scale inhibitors (such as ethylenediaminetetraacetic acid, aminotrimethylenephosphonic acid, etc.) and corrosion inhibitors (such as ferric nitrate, copper nitrate, etc.) are added to the mixer 2 through the scale inhibitor and corrosion inhibitor storage tank to reduce scaling or corrosion of the equipment and pipelines, thereby extending the service life of the equipment.

[0043] In this application, the hot water injection device 3 is, for example, a common pipe structure, or a hollow columnar structure that is closed at one end and connected to the mixer 2 at the other end, and has multiple drain holes on the side wall.

[0044] During operation, the boiler feedwater pump 10 pumps softened demineralized water from the softened water tank 4 into the steam boiler 1. Simultaneously, the fuel supply tank 5 supplies fuel (such as oil or compressed gas) to the furnace of the steam boiler 1, while the blower 11 draws in outside air to provide oxygen for fuel combustion. The heat generated by fuel combustion vaporizes the softened water, forming high-pressure steam (170~180℃, 0.8MPa). This steam exits the steam boiler 1 and enters the mixer 2 as a heat source. Meanwhile, the well-produced fluid stored in the well-produced fluid storage device 6, after being filtered by the Y-shaped filter 61, is transferred to the mixer 2 by the transfer pump 20 (at this time, the three-way valve is switched to connect the transfer pump 20 and the mixer 2, while the drain line 9 is blocked). After mixing with the steam, the fluid is heated to form hot water at a temperature of 85~90℃. This hot water is then supplied to the hot water injection device 3 for heating the oil well.

[0045] This application provides an oil well heating system. By setting up a mixer 2, the steam produced by the steam boiler 1 is mixed with the well bottom produced fluid stored in the well bottom produced fluid storage device 6 to form hot water with high temperature. The hot water is then introduced into the hot water injection device 3 for injection into the oil well to heat the oil well. The system of this application heats the oil well by using the above-mentioned device, which overcomes the disadvantages of steam heating, such as easy steam escape, resulting in high steam consumption and high energy consumption. Moreover, the use of hot water heating has the beneficial effects of fast heating speed and uniform heating due to the fluidity of the liquid.

[0046] like Figure 1 As shown, optionally, a buffer device 7 is provided between the mixer 2 and the hot water injection device 3.

[0047] In this application, the buffer device 7 can effectively reduce the pipeline pressure changes caused by fluctuations in the liquid flow rate output from the mixer 2, thus ensuring a stable output liquid flow.

[0048] like Figure 1 As shown, optionally, a temperature sensor 70 is provided on the buffer device 7, and the temperature sensor 70 is electrically connected to the controller 8;

[0049] The controller 8 is also electrically connected to the blower 11 and the steam boiler 1.

[0050] During use, the temperature sensor 70 monitors the change in liquid temperature in the buffer device 7 in real time and transmits the corresponding temperature data to the controller 8. When the temperature in the buffer device 7 is detected to be lower than the preset low value, the controller 8 controls the blower 11 to increase the air flow and controls the steam boiler 1 to increase the fuel inlet opening, thereby increasing the degree of combustion in the furnace and increasing the temperature of the steam output by the steam boiler, thereby increasing the temperature of the liquid in the buffer device 7.

[0051] like Figure 1 As shown, optionally, the transfer pump 20 and the mixer 2 are connected to the drain line 9 via a three-way valve 100.

[0052] In this application, if the water pressure supplied by the transfer pump 20 is too high or the liquid level in the mixer 2 is too high, the three-way valve 100 can be switched to connect the sewage pipeline 9 and the transfer pump 20 and block the mixer 2, so that the well bottom produced fluid pumped by the transfer pump 20 can be transferred into the sewage pipeline 9 for treatment.

[0053] like Figure 2 As shown, optionally, the buffer device 7 includes a buffer shell 71;

[0054] A liquid storage bladder 72 is provided inside the buffer shell 71, and a buffer layer 73 is filled in the space between the outer wall of the liquid storage bladder 72 and the buffer shell 71.

[0055] A connecting tube is provided on each of the two opposite side walls of the reservoir 72. The connecting tube passes through the buffer shell 71 and extends out of the buffer shell 71. The part of the connecting tube between the reservoir 72 and the buffer shell 71 is a retractable flexible tube. The connecting tube is fixedly connected to the buffer shell 71.

[0056] In this application, when hot water enters the buffer device 7, it will enter the storage bladder 72 (the storage bladder is a bladder-like structure with a certain elasticity made of materials such as rubber) through the pipeline for temporary storage, and then be discharged from the storage bladder 72 to the hot water injection device 3 for use in heating the oil well.

[0057] Since the space between the outer wall of the reservoir 72 and the buffer shell 71 is filled with a buffer layer 73 (the buffer layer 73 is made of an elastic material such as rubber or a spring), when the flow rate of the liquid entering the buffer device 7 fluctuates, the buffer layer 73 can absorb the sudden pressure change in the reservoir 72 caused by the fluctuation of the liquid flow rate, thereby ensuring the stability of the liquid flow output from the buffer device 7.

[0058] like Figure 3 As shown, optionally, the reservoir 72 is also covered with a restraint net 74.

[0059] In this application, the reservoir 72 is also covered by a restraint net 74. The restraint net 74 can prevent the reservoir 72 from being damaged due to excessive expansion and can effectively extend the service life of the reservoir 72. The restraint net 74 is made of materials such as nylon.

[0060] like Figure 4 and Figure 5 As shown, optionally, the mixer 2 includes a housing 21;

[0061] A partition 22 is provided inside the housing 21 in the radial direction, and there is space between the top and bottom of the partition 22 and the housing 21.

[0062] A gas distribution pipe 23 is provided in the lower part of the shell 21 along the axial direction of the shell 21. The inlet end of the gas distribution pipe 23 is connected to the steam boiler 1. The gas distribution pipe 23 is located between the partition plate 22 and the shell 21.

[0063] A liquid distribution plate 24 is provided in the upper part of the housing 21 near the input end of the air distribution pipe 23, and a liquid inlet 201 is provided on the housing 21 above the liquid distribution plate 24.

[0064] The bottom of the housing 21 is provided with a liquid outlet 202, and the upper part of the housing 21 is provided with a vent 203 away from the liquid inlet 201.

[0065] In this application, during use, a certain amount of water is first injected into the casing 21 via the transfer pump 20 to submerge the gas distribution pipe 23. Then, high-temperature steam is introduced into the gas distribution pipe 23, traveling from bottom to top from the bottom of the casing 21 of the mixer 2. Simultaneously, the bottom-hole produced fluid pumped in by the transfer pump 20 is input through the inlet 201. After entering the casing 21, the input bottom-hole produced fluid falls into the distribution plate 24 and then falls through the through hole at the bottom of the distribution plate 24. It contacts and exchanges heat with the upward-moving steam, absorbing the steam. The temperature of the liquid droplets that have absorbed the steam rises, and they then fall to the bottom of the casing 21. Some of the steam that comes into contact with the falling droplets is not absorbed by the droplets. Since the bottom-hole produced fluid contains a small amount of dissolved gases such as oxygen, these gases are discharged from the hot water during the heating process and released to the outside through the exhaust port 203.

[0066] In this application, the liquid distribution tray 24 is a box structure with multiple through holes at the bottom and an open top. The top of the liquid distribution tray 24 is fixedly connected to the inner top wall of the housing 21 (by welding or threaded connection).

[0067] like Figure 4 and Figure 5 As shown, optionally, an air guide chamber 25 is provided between the top of the partition 22 and the housing 21, and the air guide chamber 25 is connected to the air distribution plate 251 provided between the air guide chamber 25 and the air distribution pipe 23 through a conduit.

[0068] The air distribution plate 251 is separated from the liquid distribution plate 24 by the partition plate 22.

[0069] In this application, some of the steam that comes into contact with and exchanges heat with the liquid droplets leaking from the liquid distribution plate 24 will continue to rise. (Since the lower end of the baffle 22 is close to the bottom of the shell 21, the lower end of the baffle 22 is submerged in the liquid during normal use, and the steam cannot pass through the lower end of the baffle 22 to the other side.) The rising steam will gather in the air guide chamber 25, and then enter the air distribution plate 251 through the conduit. It will then be discharged from the through hole at the bottom of the air distribution plate 251 into the heated liquid for secondary absorption and heat exchange.

[0070] In this application, the steam distribution plate 251 is a hollow, flat shell structure with multiple through holes at the bottom for discharging steam.

[0071] An oil well heating system, the working process of which is as follows:

[0072] During operation, the boiler feed pump 10 pumps the softened demineralized water from the softened water tank 4 into the steam boiler 1. Simultaneously, the fuel supply tank 5 supplies fuel (such as oil or compressed gas) to the furnace of the steam boiler 1. At the same time, the blower 11 draws in outside air into the furnace to provide the oxygen required for fuel combustion. The heat generated by fuel combustion heats and vaporizes the softened water, forming high-pressure steam (170~180℃, 0.8MPa). The steam is discharged from the steam boiler 1 and enters the mixer 2 as a heat source. Meanwhile, the well-produced fluid stored in the well-produced fluid storage device 6, after being filtered by the Y-shaped filter 61, is transferred to the mixer 2 by the transfer pump 20 (at this time, the three-way valve 100 is switched to connect the transfer pump 20 and the mixer 2, while the drain line 9 is blocked). After mixing with the steam, the mixture is heated to form hot water.

[0073] When heating is carried out in mixer 2, a certain amount of water is first injected into the shell 21 through the transfer pump 20 to cover the gas distribution pipe 23 and the gas distribution plate 251. Then, high temperature steam is introduced into the gas distribution pipe 23 and travels from bottom to top from the bottom of the shell 21 of mixer 2. At the same time, the bottom produced fluid pumped in by the transfer pump 20 is input from the inlet 201. After entering the shell 21, the input bottom produced fluid falls into the distribution plate 24 and falls out through the through hole at the bottom of the distribution plate 24. The liquid droplets come into contact with the rising steam for heat exchange and absorb the steam. The temperature of the steam-absorbing droplets rises and they fall to the bottom of the shell 21. Some of the steam that comes into contact with the falling droplets is not absorbed by the droplets and continues to rise (because the lower end of the baffle 22 is close to the bottom of the shell 21, the lower end of the baffle 22 is submerged in the liquid during normal use, and the steam cannot pass through the lower end of the baffle 22 to the other side). The rising steam will collect in the gas guide chamber 25 and then enter the gas distribution plate 251 through the conduit. It will then be discharged from the through hole at the bottom of the gas distribution plate 251 into the heated liquid for secondary absorption and heat exchange. Since a small amount of gas such as oxygen is dissolved in the produced fluid at the bottom of the well, these gases are discharged from the hot water during the heating process and discharged to the outside through the exhaust port 203.

[0074] As the produced fluid is added to the bottom of the well, the liquid level inside the casing 21 gradually rises. Steam discharged from the gas distribution pipe 23 enters the liquid, further heating it. The high velocity of the steam jet also acts as a stirrer, ensuring the produced fluid is heated evenly. The hot water, heated to a preset temperature (85~90℃), is discharged from the outlet 202 and flows into the buffer device 7 for temporary storage.

[0075] When hot water enters the buffer device 7, it will pass through a pipe into the storage bladder 72 for temporary storage, and then be discharged from the storage bladder 72 into the hot water injection device 3 to supply the oil well for heating.

[0076] During use, if the water pressure supplied by the transfer pump 20 is too high or the liquid level in the mixer 2 is too high, the three-way valve 100 can be switched to connect the sewage pipeline 9 and the transfer pump 20 and block the mixer 2, so that the well bottom produced fluid pumped by the transfer pump 20 can be transferred to the sewage pipeline 9 for treatment.

[0077] During use, the temperature sensor 70 monitors the change in liquid temperature in the buffer device 7 in real time and transmits the corresponding temperature data to the controller 8. When the temperature in the buffer device 7 is detected to be lower than the preset low value, the controller 8 controls the blower 11 to increase the air flow and controls the steam boiler 1 to increase the fuel inlet opening, thereby increasing the degree of combustion in the furnace and increasing the temperature of the steam output by the steam boiler, thereby increasing the temperature of the liquid in the buffer device 7.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. An oil well heating system, characterized in that, It includes a steam boiler (1), a mixer (2), and a hot water injection device (3) connected in series. The steam boiler (1) is connected to the softened water tank (4) via a boiler feed water pump (10); The steam boiler (1) is also connected to a blower (11) and a fuel supply box (5); The mixer (2) is also connected to the bottom-of-well produced fluid storage device (6) via a transfer pump (20); A Y-shaped filter (61) is also provided between the fluid transfer pump (20) and the bottom-hole produced fluid storage device (6). The hot water injection device (3) is installed in the oil well.

2. The oil well heating system according to claim 1, characterized in that, A buffer device (7) is provided between the mixer (2) and the hot water injection device (3).

3. The oil well heating system according to claim 2, characterized in that, A temperature sensor (70) is provided on the buffer device (7), and the temperature sensor (70) is electrically connected to the controller (8); The controller (8) is also electrically connected to the blower (11) and the steam boiler (1).

4. The oil well heating system according to claim 1, characterized in that, The transfer pump (20) and the mixer (2) are connected to the drain line (9) via a three-way valve (100).

5. The oil well heating system according to claim 2, characterized in that, The buffer device (7) includes a buffer shell (71); The buffer shell (71) is provided with a liquid storage bladder (72), and the space between the outer wall of the liquid storage bladder (72) and the buffer shell (71) is filled with a buffer layer (73). The liquid storage bladder (72) has connecting pipes on its opposite side walls. The connecting pipes pass through the buffer shell (71) and extend out of the buffer shell (71). The part of the connecting pipe between the liquid storage bladder (72) and the buffer shell (71) is a retractable flexible tube. The connecting pipe is fixedly connected to the buffer shell (71).

6. The oil well heating system according to claim 5, characterized in that, The reservoir (72) is also covered with a restraint net (74).

7. The oil well heating system according to any one of claims 1 to 6, characterized in that, The mixer (2) includes a housing (21); A partition (22) is provided inside the housing (21) in the radial direction, and a space is left between the top and bottom of the partition (22) and the housing (21); A gas distribution pipe (23) is provided in the lower part of the housing (21) along the axial direction of the housing (21). The input end of the gas distribution pipe (23) is connected to the steam boiler (1). The gas distribution pipe (23) is located between the partition (22) and the housing (21). A liquid distribution plate (24) is provided in the upper part of the housing (21) near the input end of the air distribution pipe (23), and a liquid inlet (201) is provided on the housing (21) above the liquid distribution plate (24). The bottom of the housing (21) is provided with a liquid outlet (202), and the upper part of the housing (21) is provided with a vent (203) away from the liquid inlet (201).

8. The oil well heating system according to claim 7, characterized in that, An air guide chamber (25) is provided between the top of the partition (22) and the shell (21). The air guide chamber (25) is connected to the air distribution plate (251) provided between the air guide chamber (25) and the air distribution pipe (23) through a conduit. The air distribution plate (251) is separated from the liquid distribution plate (24) by a partition (22).

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