Gas combustion system and carbon dioxide flooding system

Abstract

The application relates to the technical field of oil exploitation and discloses a gas combustion system and a carbon dioxide oil displacement system, wherein the gas combustion system comprises a supply device, a fluidized bed boiler and a cyclone separator; the supply device is provided with a containing cavity for storing hydrocarbons, and the supply device is provided with a supply port in communication with the containing cavity; the fluidized bed boiler is provided with a hearth for burning the hydrocarbons, and the fluidized bed boiler is provided with a first boiler port, a second boiler port, a third boiler port and a fourth boiler port in communication with the hearth respectively, the first boiler port is in communication with the supply port, and the second boiler port is in communication with the atmosphere; and the cyclone separator is provided with a separation cavity for separating flue gas discharged from the hearth. The application can realize the combination of the carbon dioxide oil displacement technology and the gas combustion system in the technical field of oil exploitation, and provides a new idea for the preparation of carbon dioxide and oil displacement.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil exploitation, in particular to a gas combustion system and a carbon dioxide oil displacement system. BACKGROUND

[0002] The carbon dioxide oil displacement technology refers to injecting carbon dioxide gas into an oil layer, and then pressing out the oil to realize oil exploitation and improve the oil recovery rate. The current oil displacement technology includes water flooding, carbon dioxide flooding and the like, among which the carbon dioxide flooding has a wide application prospect. Meanwhile, the carbon dioxide flooding technology can effectively reduce the greenhouse gas emission and achieve the carbon capture effect.

[0003] In the related art, how to continuously obtain carbon dioxide in the process of using the carbon dioxide to displace oil is a technical problem to be solved. SUMMARY

[0004] The present application is made based on the discovery and understanding of the inventors on the following facts and problems:

[0005] In the process of researching the carbon dioxide oil displacement, the carbon dioxide acquisition is a key point of the carbon dioxide oil displacement. In the actual investigation, there is generally abundant natural gas near the oil field, which can be directly used to generate carbon dioxide and water vapor, thereby preparing for oil displacement.

[0006] The present application aims to at least solve one of the technical problems in the related art. To this end, the embodiments of the present application propose a gas combustion system and a carbon dioxide oil displacement system, which can realize the combination of the carbon dioxide oil displacement technology and the gas combustion system in the oil exploitation technology, and provide a new idea for the carbon dioxide preparation and oil displacement.

[0007] The gas combustion system of the present application comprises a supply device, a fluidized bed boiler and a cyclone separator, the supply device has a containing cavity for storing hydrocarbons, and the supply device is provided with a supply port in communication with the containing cavity;

[0008] The fluidized bed boiler has a hearth for burning hydrocarbons, and the fluidized bed boiler is provided with a first boiler port, a second boiler port, a third boiler port and a fourth boiler port in communication with the hearth, respectively, the first boiler port is in communication with the supply port, and the second boiler port is in communication with the atmosphere;

[0009] The cyclone separator has a separation chamber for separating flue gas discharged from the furnace, and the cyclone separator is provided with a first separation opening, a second separation opening and a third separation opening which respectively communicate with the separation chamber, the first separation opening communicates with the third boiler opening to allow flue gas in the furnace to enter the separation chamber, the second separation opening communicates with the fourth boiler opening to allow separation products in the separation chamber to enter the furnace, and the third separation opening is used for discharging water vapor and carbon dioxide in the separation chamber.

[0010] The gas combustion system can combust hydrocarbons and oxygen in the fluidized bed boiler to generate water vapor and carbon dioxide. At the same time, the cyclone separator can separate flue gas (carbon dioxide, water vapor and incompletely combusted hydrocarbons) in the fluidized bed boiler, and then the incompletely combusted hydrocarbons can be discharged into the fluidized bed boiler for complete combustion, and the separated carbon dioxide and water vapor can be prepared for oil displacement. That is, the present application realizes the combination of carbon dioxide oil displacement technology and circulating fluidized bed combustion system in oil exploitation technology, and provides a new idea for carbon dioxide preparation and oil displacement.

[0011] Optionally, the first boiler opening is located at the bottom of the fluidized bed boiler; and / or

[0012] the second boiler opening is located at the bottom of the fluidized bed boiler; and / or

[0013] the third boiler opening is located at the top of the fluidized bed boiler; and / or

[0014] the fourth boiler opening is located between the first boiler opening and the third boiler opening.

[0015] Optionally, the gas combustion system further comprises:

[0016] a vaporization tank connected between the supply opening and the first boiler opening, the vaporization tank having a vaporization chamber for vaporizing hydrocarbons.

[0017] Optionally, the gas combustion system further comprises:

[0018] a spraying device arranged in the furnace and communicating with the first boiler opening for spraying hydrocarbons into the furnace.

[0019] Optionally, the gas combustion system further comprises:

[0020] a first fan arranged in the second boiler opening for sending gas into the furnace.

[0021] Optionally, the gas combustion system further comprises:

[0022] An air separation device is in communication with the second boiler port.

[0023] Optionally, the gas combustion system further comprises:

[0024] A second fan is provided between the second separation port and the fourth boiler port to send gas into the furnace.

[0025] Optionally, the fluidized bed boiler comprises a wind distribution plate provided in the furnace and located at the second boiler port to change the gas flow into the furnace through the second boiler port.

[0026] Optionally, the fluidized bed boiler comprises a superheater buried pipe provided in the furnace.

[0027] The carbon dioxide oil displacement system of the present application comprises:

[0028] A gas combustion system according to any one of claims 1-9;

[0029] A gas injection well, one end of which is in communication with the third separation port;

[0030] A horizontal well, one end of which is in communication with the other end of the gas injection well;

[0031] An oil outlet well, one end of which is in communication with the other end of the horizontal well;

[0032] An oil storage tank having a storage cavity for storing oil, the storage cavity being in communication with the other end of the oil outlet well. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 is a schematic diagram of the carbon dioxide oil displacement system of an embodiment of the present application.

[0034] REFERENCE NUMERALS:

[0035] 1 - supply device, 1a - containing cavity, 1b - supply port, 2 - vaporization tank, 3 - fluidized bed boiler, 3a - furnace, 3b - first boiler port, 3c - second boiler port, 3d - third boiler port, 3e - fourth boiler port, 3f - wind distribution plate, 3g - superheater buried pipe, 4 - cyclone separator, 4a - separation cavity, 4b - first separation port, 4c - second separation port, 4d - third separation port, 5 - injection device, 6 - first fan, 7 - air separation device, 8 - second fan, 9 - gas injection well, 10 - horizontal well, 11 - oil outlet well, 12 - oil storage tank. DETAILED DESCRIPTION

[0036] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0037] The following describes an embodiment of the gas combustion system for carbon dioxide-assisted oil recovery according to the present invention, with reference to the accompanying drawings. Figure 1 As shown, the gas combustion system of this embodiment includes a supply device 1, a fluidized bed boiler 3, and a cyclone separator 4.

[0038] The supply device 1 has a receiving cavity 1a for storing hydrocarbons, and a supply port 1b communicating with the receiving cavity 1a. The fluidized bed boiler 3 has a furnace 3a for burning hydrocarbons, and a first boiler port 3b, a second boiler port 3c, a third boiler port 3d, and a fourth boiler port 3e communicating with the furnace 3a respectively. The first boiler port 3b is connected to the supply port 1b, and the second boiler port 3c is connected to the atmosphere. The cyclone separator 4 has a separation cavity 4a for separating the flue gas discharged from the furnace 3a, and a first separation port 4b, a second separation port 4c, and a third separation port 4d communicating with the separation cavity 4a respectively. The first separation port 4b is connected to the third boiler port 3d to allow the flue gas in the furnace 3a to enter the separation cavity 4a, the second separation port 4b is connected to the fourth boiler port 3e to allow the separated material in the separation cavity 4a to enter the furnace 3a, and the third separation port 4d is used to discharge water vapor and carbon dioxide from the separation cavity 4a.

[0039] The gas combustion system of this invention can generate steam and carbon dioxide by burning hydrocarbons and oxygen in a fluidized bed boiler 3. Simultaneously, a cyclone separator 4 can separate the flue gas (carbon dioxide, steam, and incompletely burned hydrocarbons) in the fluidized bed boiler 3. The incompletely burned hydrocarbons are then discharged back into the fluidized bed boiler 3 for complete combustion, and the separated carbon dioxide and steam can be used to prepare for oil displacement. In other words, this invention combines carbon dioxide enhanced oil recovery (CEM) technology with a circulating fluidized bed combustion system in oil extraction, providing a new approach to carbon dioxide production and oil displacement.

[0040] The following describes some specific embodiments of a gas combustion system for carbon dioxide-assisted oil recovery.

[0041] In this embodiment of the invention, the hydrocarbon is a gas, preferably methane. Specifically, oil fields are generally located near abundant natural gas resources, the main component of which is methane gas. Carbon dioxide can be produced by burning methane to provide a gas source for carbon dioxide flooding. Meanwhile, the products of the reaction between methane and oxygen are carbon dioxide and water, which can be used for carbon dioxide flooding, water flooding, and gas-water mixed flooding.

[0042] In some embodiments, as shown in Figure 1 The supply device 1 has a containing cavity 1a for storing hydrocarbon, which can be in gaseous or liquid state. The hydrocarbon in the present application is methane, which is in liquid state in the supply device 1, facilitating transportation and storage. The supply device 1 is provided with a supply port 1b in communication with the containing cavity 1a.

[0043] In some embodiments, as shown in Figure 1 The fluidized bed boiler 3 has a furnace 3a for burning hydrocarbon, and is provided with a first boiler port 3b, a second boiler port 3c, a third boiler port 3d and a fourth boiler port 3e in communication with the furnace 3a respectively. The first boiler port 3b is in communication with the supply port 1b, and the hydrocarbon in the supply device 1 can enter the furnace 3a through the first boiler port 3b and the supply port 1b, and the hydrocarbon can be burned in the furnace 3a to generate carbon dioxide and water vapor. The second boiler port 3c is in communication with the atmosphere, and air can enter the furnace 3a through the second boiler port 3c and the atmosphere source continuously to promote the combustion of hydrocarbon in the furnace 3a.

[0044] Specifically, the fluidized bed boiler 3 is used as the reactor, which has the properties of strong heat and mass transfer and constant temperature easy to maintain. In the process of fluidized combustion, the two-phase flow of bed material particles and gas makes it have good heat transfer performance, ensuring uniform temperature distribution in the fluidized bed, preventing local heat accumulation, controlling the reaction temperature of hydrocarbon, and avoiding explosion.

[0045] In some embodiments, the amount of flue gas generated by the combustion of hydrogen-oxygen compounds (methane) is small, and in order to achieve rapid fluidization inside the furnace 3a, the fluidization wind speed of the furnace 3a cannot be set too high, and the fluidization wind speed in the furnace 3a is controlled to be 1 m / s ~ 2 m / s.

[0046] In some embodiments, the temperature in the furnace 3a is controlled to be 880℃ ~ 980℃. Specifically, the temperature of the combustion of hydrogen-oxygen compounds (methane) is relatively high, about 1500℃, in order to prevent the particles in the furnace 3a from slagging due to the excessively high temperature in the furnace, the average temperature of the furnace needs to be controlled to be 880℃ ~ 980℃, which is still higher than the general circulating fluidized bed combustion temperature, but since the reactants are methane and pure oxygen, the problem of increased NOx emissions caused by excessively high temperature does not need to be considered.

[0047] In some embodiments, as shown in Figure 1 The fluidized bed boiler 3 includes a wind distribution plate 3f arranged in the furnace 3a, which is located at the second boiler port 3c to change the airflow entering the furnace 3a through the second boiler port 3c.

[0048] Specifically, the air distribution plate 3f can control the flow rate of the gas entering from the second boiler port 3c, i.e., can reduce the flow rate of the gas, control the reaction speed between the gas and the hydroxide, and avoid the explosion of the gas and the hydroxide.

[0049] In some embodiments, as shown in FIG. 1, the fluidized bed boiler 3 includes a superheater embedded tube 3g arranged in the furnace 3a. Figure 1

[0050] Specifically, arranging the superheater embedded tube 3g in the fluidized bed boiler 3 can reduce the temperature in the furnace 3a, and avoid the damage of the fluidized bed boiler 3 caused by the temperature in the furnace 3a. That is, the superheater embedded tube 3g controls the temperature in the furnace 3a to be within a set range, and prevents the temperature in the furnace 3a from being too high.

[0051] In some embodiments, a water-cooled wall is arranged around the fluidized bed boiler 3, so as to control the temperature of the furnace 3a to be within a set range, and prevent the fluidized bed boiler 3 from over-temperature.

[0052] In some embodiments, as shown in FIG. 1, the cyclone separator 4 has a separation chamber 4a for separating the flue gas discharged from the furnace 3a. The cyclone separator 4 can separate the flue gas discharged from the furnace 3a, separate carbon dioxide and water vapor, and then return the unburned hydrocarbon compounds to the furnace 3a for continuous combustion. The cyclone separator 4 is provided with a first separation port 4b, a second separation port 4c and a third separation port 4d which respectively communicate with the separation chamber 4a. The first separation port 4b communicates with the third boiler port 3d to allow the flue gas in the furnace 3a to enter the separation chamber 4a. The second separation port 4b communicates with the fourth boiler port 3e to allow the separated substances in the separation chamber 4a to enter the furnace 3a. The third separation port 4d is used to discharge water vapor and carbon dioxide in the separation chamber 4a. Figure 1 In some embodiments, as shown in FIG. 1, the first boiler port 3b is located at the bottom of the fluidized bed boiler 3.

[0053] Figure 1 In some embodiments, as shown in FIG. 1, the second boiler port 3c is located at the bottom of the fluidized bed boiler 3.

[0054] In some embodiments, as shown in FIG. 1, the third boiler port 3d is located at the top of the fluidized bed boiler 3. Figure 1 In some embodiments, as shown in FIG. 1, the fourth boiler port 3e is located between the first boiler port 3d and the third boiler port 3c.

[0055] Figure 1 In some embodiments, as shown in FIG. 1, the fourth boiler port 3e is located between the first boiler port 3d and the third boiler port 3c.

[0056] In some embodiments, as shown in FIG. 1, the fourth boiler port 3e is located between the first boiler port 3d and the third boiler port 3c. Figure 1 In some embodiments, as shown in FIG. 1, the fourth boiler port 3e is located between the first boiler port 3d and the third boiler port 3c.

[0057] Figure 1 ​​​​As shown, the gas combustion system further comprises a vaporization tank 2, which is connected between the supply port 1b and the first boiler port 3b, and has a vaporization cavity for vaporizing the hydrocarbon.

[0058] Specifically, when the hydrogen compound in the supply device 1 is in liquid state, the vaporization tank 2 can vaporize the liquid hydrogen compound, so as to ensure that the vaporized hydrogen compound can be fully combusted in the fluidized bed boiler 3.

[0059] In some embodiments, as shown, Figure 1 As shown, the gas combustion system further comprises a spraying device 5, which is arranged in the hearth 3a and communicates with the first boiler port 3b, for spraying the hydrocarbon into the hearth 3a.

[0060] Specifically, the spraying device 5 can spray the vaporized hydrogen compound into the hearth 3a, so as to promote the combustion of the hydrogen compound. In addition, the speed of spraying the hydrogen compound into the hearth 3a can be controlled by the spraying device 5, so as to control the combustion speed of the hydrogen compound.

[0061] In some embodiments, as shown, Figure 1 As shown, the gas combustion system further comprises a first air blower 6, which is arranged in the second boiler port 3c, for sending the gas into the hearth 3a. Specifically, the first air blower 6 can send the air into the hearth 3a.

[0062] In some embodiments, as shown, Figure 1 As shown, the gas combustion system further comprises an air separation device 7, which communicates with the second boiler port 3c.

[0063] Specifically, the air separation device 7 can separate the air to obtain high-purity pure oxygen, so as to avoid other gases entering the hearth 3a to affect the combustion of the hydrogen compound.

[0064] In some embodiments, as shown, Figure 1 As shown, the gas combustion system further comprises a second air blower 8, which is arranged between the second separation port 4c and the fourth boiler port 3e, for sending the gas into the hearth 3a.

[0065] Specifically, the second air blower 8 can send the gas in the atmosphere into the hearth 3a to increase the oxygen content in the hearth 3a, so as to ensure that the hydrogen compound can be fully combusted, by arranging the second air blower 8 between the second separation port 4c and the fourth boiler port 3e.

[0066] Optionally, the second separation port 4c can be provided with an air separation device to obtain high-purity oxygen.

[0067] The carbon dioxide oil displacement system in the present application comprises a gas combustion system, a gas injection well 9, a horizontal well 10, an oil outlet well 11 and an oil storage tank 12. The gas combustion system is the above-mentioned gas combustion system, one end of the gas injection well 9 is communicated with the third separation port 4d, one end of the horizontal well 10 is communicated with the other end of the gas injection well 9, one end of the oil outlet well 11 is communicated with the other end of the horizontal well 10, and the oil storage tank 12 has a storage cavity for storing oil, and the storage cavity is communicated with the other end of the oil outlet well 11. Specific embodiment 1

[0069] On a 130t / h circulating fluidized bed boiler 3, the methane combustion heat value is 55000kJ / kg, the methane fuel consumption in the fluidized bed boiler 3 is 8.27t / h, and the excess oxygen coefficient is 1.1, the pure oxygen consumption is 18.19t / h. After using the boiler to burn, the steam generated per hour is 130t, the steam pressure is 13.73MPa, the steam temperature is 540℃, and at the same time, 24.81t of flue gas composed of carbon dioxide and water can be generated per hour for oil displacement. Specific embodiment 2

[0071] On a 150t / h circulating fluidized bed boiler, the methane combustion heat value is 55000kJ / kg, the methane fuel consumption in the fluidized bed boiler 3 is 7.77t / h, and the excess oxygen coefficient is 1.1, the pure oxygen consumption is 17.10t / h. After using the boiler to burn, the steam generated per hour is 150t, the steam pressure is 9.81MPa, the steam temperature is 540℃, and at the same time, 23.31t of flue gas composed of carbon dioxide and water can be generated per hour for oil displacement.

[0072] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0073] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0074] In the present application, unless specifically defined otherwise, the terms "mount", "connected", "connecting", "fixed", "unfixed", and the like are to be construed in a broad sense, for example, they can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection, or communication with each other; can be direct connection, or indirect connection via intermediate medium; can be internal communication of two elements, or interaction between two elements, unless specifically defined otherwise. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0075] In the present application, unless specifically defined otherwise, the first feature is "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact via an intermediate medium. Moreover, the first feature "on", "above" and "over" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "under", "below" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0076] In the present application, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" and the like mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, different embodiments or examples described in the present specification and the features of different embodiments or examples can be combined and combined by those skilled in the art without contradiction.

[0077] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and cannot be construed as limiting the present application, and the changes, modifications, replacements and variations of the above embodiments made by those skilled in the art are within the scope of the present application.

Claims

1. A gas combustion system for carbon dioxide flooding, characterized by, Comprising: a supply device having a containing cavity for storing hydrocarbon, the supply device being provided with a supply port in communication with the containing cavity; a fluidized bed boiler having a hearth for burning hydrocarbon, the fluidized bed boiler being provided with a first boiler port, a second boiler port, a third boiler port and a fourth boiler port in communication with the hearth respectively, the first boiler port being in communication with the supply port, the second boiler port being in communication with the atmosphere; a cyclone separator having a separating cavity for separating flue gas discharged from the hearth, the cyclone separator being provided with a first separating port, a second separating port and a third separating port in communication with the separating cavity respectively, the first separating port being in communication with the third boiler port to allow flue gas in the hearth to enter the separating cavity, the second separating port being in communication with the fourth boiler port to allow separation product in the separating cavity to enter the hearth, the third separating port being for discharging water vapor and carbon dioxide in the separating cavity; a vaporization tank connected between the supply port and the first boiler port, the vaporization tank having a vaporization cavity for vaporizing hydrocarbon.

2. The gas combustion system for carbon dioxide flooding of claim 1, wherein, the first boiler port is located at the bottom of the fluidized bed boiler; and / or the second boiler port is located at the bottom of the fluidized bed boiler; and / or the third boiler port is located at the top of the fluidized bed boiler; and / or the fourth boiler port is located between the first boiler port and the third boiler port.

3. The gas combustion system for carbon dioxide flooding of claim 1, wherein, Further comprising: an injection device provided in the hearth and in communication with the first boiler port for injecting hydrocarbon into the hearth.

4. The gas combustion system for carbon dioxide flooding of claim 1, wherein, Further comprising: a first air blower provided in the second boiler port for sending gas into the hearth.

5. The gas combustion system for carbon dioxide flooding of claim 1, wherein, Further comprising: an air separation device in communication with the second boiler port.

6. The gas combustion system for carbon dioxide flooding of claim 1, wherein, Further comprising: a second air blower provided between the second separating port and the fourth boiler port for sending gas into the hearth.

7. The gas combustion system for carbon dioxide flooding of any one of claims 1-6, wherein, The fluidized bed boiler comprises a wind distribution plate provided in the hearth, the wind distribution plate being located at the second boiler port to change the air flow into the hearth from the second boiler port.

8. The gas combustion system for carbon dioxide flooding of any one of claims 1-6, wherein, The fluidized bed boiler comprises a superheater embedded tube provided in the hearth.

9. A carbon dioxide flooding system, characterized by, Comprising: a gas combustion system according to any one of claims 1-8; a gas injection well, one end of the gas injection well being in communication with the third separating port; a horizontal well, one end of the horizontal well being in communication with the other end of the gas injection well; an oil outlet well, one end of the oil outlet well being in communication with the other end of the horizontal well; an oil storage tank having a storage cavity for storing oil, the storage cavity being in communication with the other end of the oil outlet well.

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