Special electric heating boiler system for oil field steam injection

Abstract

The utility model discloses a kind of special electric heating boiler systems of oilfield steam injection, several layers of electric heater, evaporation section tube bundle and the superheating section tube bundle located above evaporation section tube bundle are installed in the sealed space surrounded by thermal insulation wall body.Evaporation section tube bundle's water inlet end is connected with the drainage end of high-pressure pump;Evaporation section tube bundle's saturated steam discharge end is connected with the water vapor inlet end of steam-water separator, the steam outlet end of steam-water separator is connected with the steam inlet end of superheating section tube bundle, and the steam outlet end of superheating section tube bundle is connected with the steam inlet end of mixing device.The water outlet end of steam-water separator is connected with the water inlet end of mixing device, and the steam outlet end of mixing device is used to connect oilfield steam injection pipeline.The utility model uses electric energy to replace fossil fuel combustion to solve carbon emission problem, and fully utilizes saturated water and its heat energy separated by steam-water separator.The separated saturated water carries part of inorganic salt and is taken out of boiler system, reducing the accumulation and deposition of inorganic salt in boiler.

Description

Technical Field

[0001] This utility model relates to the technical field of auxiliary equipment for oilfield development. Specifically, it relates to a steam-electric boiler system used for steam injection in oilfields. Background Technology

[0002] Existing oilfield steam injection boilers mostly use coal, carbon, gas, or oil as fuel, resulting in problems such as high carbon emissions and large fluctuations in thermal efficiency. For example, Chinese utility model patent CN201546689U discloses "a superheated steam boiler for oilfield steam injection," which adopts a coal-fired chain grate combustion system and a natural steam-water circulation structure. Another example is Chinese utility model patent CN210087302U, which discloses "a clean carbon boiler oil well steam injection heating system," which utilizes the heat released from burning clean carbon to heat flowing water, turning it into steam, and then injects steam into the oil well through the oil well steam injection unit for heating.

[0003] Chinese utility model patent CN210267168U discloses a "solar thermal oilfield steam injection boiler system," which uses solar energy to convert into electrical energy to heat water and generate steam for oilfield steam injection, solving the pollution emission problem of conventional fossil fuel combustion in oilfields. Wastewater from the steam generator is continuously and evenly connected to an expansion tank through a high-pressure boiler discharge valve at the wastewater outlet. The wastewater undergoes tangential movement within a cylindrical baffle in the middle of the expansion tank's outer shell and immediately vaporizes into secondary steam. After steam-water separation, the remaining wastewater is discharged to a discharge pool through pipelines. However, the still relatively hot water and its thermal energy after steam-water separation are not fully utilized, resulting in high water consumption and reduced overall heat exchange efficiency.

[0004] On the other hand, although the water entering the oilfield steam injection boiler has been pretreated, it still contains some inorganic salts. The long-term accumulation of these inorganic salts can easily cause scaling in the boiler system and even tube rupture. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a special electric heating boiler system for oilfield steam injection. First, it uses electric heating to replace fossil fuel combustion to solve the carbon emission problem and further improve the utilization rate of water and its thermal energy. Second, it reduces the accumulation of inorganic salts by removing inorganic salts from the boiler system in saturated steam.

[0006] The technical solution of this utility model is as follows:

[0007] An electric boiler system for oilfield steam injection includes a sealed space enclosed by an insulated wall. Several layers of electric heaters are installed within this sealed space. An evaporation section tube bundle and a superheated section tube bundle located above the evaporation section tube bundle are also installed within the sealed space. The system further includes a high-pressure pump, a steam-water separator, and a mixer located outside the insulated wall. The water inlet of the evaporation section tube bundle is connected to the drain of the high-pressure pump via a water supply pipe passing through the insulated wall. The saturated steam outlet of the evaporation section tube bundle is connected to the steam inlet of the steam-water separator via an evaporation section outlet pipe passing through the insulated wall. The steam outlet of the steam-water separator is connected to the steam inlet of the superheated section tube bundle via a superheated section inlet pipe passing through the insulated wall. The steam outlet of the superheated section tube bundle is connected to the steam inlet of the mixer via a superheated section outlet pipe passing through the insulated wall. The water outlet of the steam-water separator is connected to the water inlet of the mixer via a pipeline. The steam outlet of the mixer is used to connect to the oilfield steam injection pipeline.

[0008] Preferably, an inlet regulating valve is installed on the pipeline between the steam-water separator and the mixer.

[0009] Preferably, the insulated wall is composed of multiple layers of fire-resistant fiber materials.

[0010] Preferably, the evaporation section tube bundle and the superheating section tube bundle are respectively made of boiler steel tubes made of 15CrMoG.

[0011] Preferably, the tube panels of both the evaporation section tube bundle and the superheated section tube bundle are installed using a support and suspension method.

[0012] Preferably, the electric heater uses an iron-chromium-aluminum heating wire with added rare earth elements.

[0013] More preferably, the heating wire mounting area is constructed using high-alumina wire-supporting bricks.

[0014] The beneficial effects of this utility model are as follows:

[0015] First, the boiler water of this utility model first undergoes desalination, deoxygenation, and heating pretreatment. Then, it is pressurized by a high-pressure pump and sent to the evaporation section for heating and evaporation. After being heated in the evaporation section, the saturated steam dryness reaches 75-80%. It is then sent to the steam-water separator outside the furnace for steam-water separation. The separated saturated steam is then sent to the superheating section for superheating to about 395°C. The saturated water separated by the steam-water separator and the superheated steam from the superheating section are mixed in the mixer and then turned into superheated steam at about 350°C for use by the user.

[0016] The carbon emission problem was solved by using electricity to replace the combustion of fossil fuels, and the saturated water and its heat energy separated by the steam-water separator were fully utilized.

[0017] Secondly, the saturated steam heated in the evaporation section is discharged from the boiler system and sent to the steam-water separator outside the furnace for steam-water separation. The separated saturated water carries some inorganic salts out of the boiler system, reducing the accumulation and deposition of inorganic salts in the boiler. Attached Figure Description

[0018] Figure 1 This is a system flowchart of an embodiment of the present invention, used to illustrate the working principle of the present invention;

[0019] Figure 2 This is a front view structural diagram of an embodiment of the present utility model;

[0020] Figure 3 This is a side view structural diagram of an embodiment of the present utility model;

[0021] Figure 4 This is a top view of an embodiment of the present invention.

[0022] Explanation of reference numerals in the attached diagram: 1. Insulated wall; 2. Mixer; 3. Inlet water regulating valve; 4. Steam-water separator; 5. High-pressure pump; 6. Evaporation section tube bundle; 7. Electric heater; 8. Superheated section tube bundle; 9. Water supply pipe; 10. Evaporation section steam outlet pipe; 11. Superheated section steam inlet pipe; 12. Superheated section steam outlet pipe; Z. Evaporation section; G. Superheated section. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0024] like Figure 2 , Figure 3 and Figure 4 An embodiment of the dedicated electric boiler system of this utility model includes a sealed space enclosed by an insulated wall 1, within which several layers of electric heaters 7 of varying heights are installed. An evaporation section tube bundle 6 and a superheated section tube bundle 8 located above the evaporation section tube bundle 6 are also installed within the sealed space. The evaporation section tube bundle 6 is located in the upper evaporation section Z within the sealed space, and the superheated section tube bundle 8 is located in the lower superheated section G within the sealed space. Both the evaporation section Z and the superheated section G are equipped with electric heaters 7.

[0025] Combination Figure 1This embodiment also includes a high-pressure pump 5, a steam-water separator 4, and a mixer 2 disposed outside the insulation wall 1. The water inlet of the evaporation section tube bundle 6 is connected to the drain of the high-pressure pump 5 via a water supply pipe 9 passing through the insulation wall 1. The water inlet of the high-pressure pump 5 is used to connect to a water source (such as pretreated boiler water). The saturated steam discharge end of the evaporation section tube bundle 6 is connected to the steam inlet of the steam-water separator 4 via an evaporation section steam outlet pipe 10 passing through the insulation wall 1. The steam outlet of the steam-water separator 4 is connected to the steam inlet of the superheated section tube bundle 8 via a superheated section steam inlet pipe 11 passing through the insulation wall 1. The steam outlet of the superheated section tube bundle 8 is connected to the steam inlet of the mixer 2 via a superheated section steam outlet pipe 12 passing through the insulation wall 1. The water outlet of the steam-water separator 4 is connected to the water inlet of the mixer 2 via a pipeline with an inlet regulating valve 3. The steam outlet of the mixer 2 is used to connect to an oilfield steam injection pipeline.

[0026] The steam-water separator used in this invention separates saturated steam and saturated water. It is a commercially available product, such as the MQF series steam-water separator manufactured and sold by Xinxiang Mait Filtration Equipment Co., Ltd. The mixer used connects to the high-temperature, high-pressure superheated steam at the superheated section outlet and the saturated water outlet of the steam-water separator, respectively, and outputs adjustable-dryness steam to the steam injection well via injection. It is also a commercially available product, such as the HQS type mixer manufactured and sold by Hunan Wen'an Electromechanical Equipment Co., Ltd.

[0027] The boiler water first undergoes desalination and deoxygenation pretreatment, and is preheated to its saturation temperature (e.g., 104℃). Then, it is pressurized by high-pressure pump 5 and sent to evaporation section Z for heating and evaporation. After heating in evaporation section Z, the saturated steam (temperature approximately 337℃) has a dryness of 75-80%. It is then sent to external steam-water separator 4 for steam-water separation. The separated saturated steam is then sent to superheating section G for superheating to approximately 395℃. The saturated water separated by steam-water separator 4 and the superheated steam from superheating section G are mixed in mixer 2, resulting in superheated steam at approximately 350℃ for user use. By adjusting the opening of the inlet regulating valve 3, the dryness of the superheated steam is controlled. Combined with the adjustment of the input power, the superheated steam output is controlled in real time to adapt to the wellhead steam injection parameters and usage requirements.

[0028] The insulation wall 1 described in this embodiment uses multi-layer refractory fiber material, effectively providing thermal insulation and reducing heat loss from the equipment. Both the evaporation section tube bundle 6 and the superheated section tube bundle 8 described in this embodiment use high-temperature and pressure-resistant high-chromium-molybdenum (15CrMoG) boiler steel tubes to meet the heat exchange requirements of high-temperature and high-pressure superheated steam, ensuring the safe and stable operation of the system equipment. The tube panels are installed using a support and hanging method. The electric heater 7 described in this embodiment uses iron-chromium-aluminum heating wire with added rare earth elements, which significantly improves the oxidation resistance and high-temperature strength of the heating alloy, allowing the maximum operating temperature to be increased to 1350℃~1400℃. This is crucial for boilers that generate high-temperature and high-pressure superheated steam, ensuring the stability of the heating element at high temperatures. The heating wire installation area is constructed using high-alumina wire-supporting brickwork.

[0029] In this embodiment, the electrical system adopts two incoming lines. The first incoming line, consisting of three phases A, B, and C, uses a fixed power. The second incoming line, consisting of three phases A', B', and C', uses an adjustable power, which allows for real-time adjustment of the power of the evaporation section and the superheating section, facilitating power adjustment of the equipment according to load changes.

Claims

1. A special electric heating boiler system for oil field steam injection, comprising a sealed space surrounded by a heat insulation wall (1), and a plurality of layers of electric heaters (7) installed in the sealed space, characterized in that: The sealing space is also provided with an evaporation section tube bundle (6) and a superheating section tube bundle (8) above the evaporation section tube bundle (6); the system further comprises a high-pressure pump (5), a steam-water separator (4) and a mixing device (2) arranged outside the heat-insulating wall (1); the water inlet end of the evaporation section tube bundle (6) is connected to the water outlet end of the high-pressure pump (5) through a water supply pipe (9) penetrating through the heat-insulating wall (1); the saturated steam outlet end of the evaporation section tube bundle (6) is connected to the water vapor inlet end of the steam-water separator (4) through an evaporation section outlet pipe (10) penetrating through the heat-insulating wall (1); the steam outlet end of the steam-water separator (4) is connected to the steam inlet end of the superheating section tube bundle (8) through a superheating section inlet pipe (11) penetrating through the heat-insulating wall (1); the steam outlet end of the superheating section tube bundle (8) is connected to the steam inlet end of the mixing device (2) through a superheating section outlet pipe (12) penetrating through the heat-insulating wall (1); the water outlet end of the steam-water separator (4) is connected to the water inlet end of the mixing device (2) through a pipeline; and the steam outlet end of the mixing device (2) is used for connecting an oilfield steam injection pipeline.

2. The special-purpose electric heating boiler system for oilfield steam injection according to claim 1, characterized in that: An inlet water regulating valve (3) is arranged on the pipeline between the steam-water separator (4) and the mixing device (2).

3. The special-purpose electric heating boiler system for oil field steam injection according to claim 1 or 2, characterized in that: The heat-insulating wall (1) is composed of multiple layers of refractory fiber material.

4. The special-purpose electric heating boiler system for oil field steam injection according to claim 1 or 2, characterized in that: The evaporation section tube bundle (6) and the superheating section tube bundle (8) are made of 15CrMoG boiler steel pipes.

5. The special-purpose electric heating boiler system for oil field steam injection according to claim 1 or 2, characterized in that: The tube panels of the evaporation section tube bundle (6) and the superheating section tube bundle (8) are all arranged in a support hanging mode.

6. The special-purpose electrically heated boiler system for oil field steam injection according to claim 1 or 2, characterized in that: The electric heater (7) is made of iron-chromium-aluminum electric heating wires with rare earth elements added.

7. The electrically heated boiler system for oil field steam injection according to claim 6, characterized in that: The electric heating wire installation part is built with high-aluminum wire laying bricks.

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