Stabilization method and device for crude oil

Abstract

The present application relates to the field of crude oil processing and gathering, and particularly relates to a method and device for stabilizing crude oil, which comprises: contacting crude oil to be stabilized with a material containing carbon dioxide to perform mass exchange, and separating to obtain stabilized crude oil and a carbon dioxide phase containing volatile components. The present application uses carbon dioxide to ensure that the stabilization process of crude oil and the efficient use of gas phase components can be realized at a lower temperature and pressure, saves energy consumption, reduces carbon emissions, improves the safety of the operation process, and reduces the loss of crude oil, further enhancing the safety of crude oil transportation.

Description

Technical Field

[0001] This invention relates to the field of crude oil processing and gathering, and more specifically to a method and apparatus for stabilizing crude oil. Background Technology

[0002] After crude oil is extracted from the ground, it enters a three-phase separator to separate the water and gas phases. However, the separated crude oil still contains a large amount of volatile components, such as methane, ethane, propane, and butane. These volatile components pose a danger to crude oil gathering and transportation, especially since the gathering and transportation process often involves temperature and pressure changes. Therefore, before gathering and transportation, crude oil needs to be treated to reduce its volatile component content. Generally, the goal is to reduce the C1-C4 components in crude oil to below 0.5 wt%. This process is called crude oil stabilization. Crude oil stabilization methods are generally divided into flash distillation and fractionation. Flash distillation includes negative pressure flash distillation and positive pressure flash distillation. Negative pressure flash distillation increases the vaporization rate of C1-C4 components at 0.05-0.07 MPa (absolute pressure) and 50-70℃, thereby extracting C1-C4 components from the crude oil. However, negative pressure flash evaporation has a small processing capacity and is limited by the vacuum level achievable by the compressor. Therefore, it can only be used to process crude oil with low C1-C4 content and is not suitable for most crude oils in my country. For conventional crude oil or crude oil with a high content of light components, positive pressure flash evaporation and fractionation methods should be used for crude oil stabilization. Both methods involve heating the crude oil and then passing it through a high-pressure stabilization tower. Mass and heat transfer between the gas and liquid phases occurs fully on the tower plates, causing the C1-C4 components to rapidly vaporize and ultimately be removed from the crude oil. The pressure and temperature of positive pressure flash evaporation are generally above 0.2-0.3 MPa and 120℃, while the temperature of fractionation is even higher, generally above 200℃. Therefore, both positive pressure flash evaporation and fractionation methods require a large amount of energy for heating and pressurization. Based on the characteristics of Chinese oil products, most crude oil stabilization processes require the use of positive pressure flash evaporation. Therefore, the crude oil stabilization process consumes a large amount of energy and is accompanied by considerable carbon emissions. Moreover, the high temperature and high pressure conditions also increase the danger of the operation.

[0003] In addition, some oilfields lack adequate gas processing facilities. The light gaseous components produced by traditional crude oil stabilization methods cannot be effectively purified, recovered, or transported, and can only be burned using flares, which further increases pollution and carbon emissions. Summary of the Invention

[0004] The purpose of this invention is to overcome the problems of poor safety, high energy consumption, high pollution, and large crude oil loss in the existing technology, and to provide a crude oil stabilization method and apparatus that has the characteristics of good safety, low energy consumption, good environmental protection, and small crude oil loss.

[0005] To achieve the above objectives, the first aspect of the present invention provides a method for stabilizing crude oil, the method comprising: contacting the crude oil to be stabilized with a carbon dioxide-containing material for mass transfer exchange, and separating the stabilized crude oil and a carbon dioxide phase containing volatile components.

[0006] A second aspect of the present invention provides a crude oil stabilization device, the device comprising:

[0007] A stabilization unit, and at least one carbon dioxide-containing material inlet located at the bottom to 1 / 2 height of the stabilization unit housing, at least one crude oil inlet located at 1 / 5-4 / 5 height of the stabilization unit housing, at least one carbon dioxide phase outlet containing volatile components located at the top to 1 / 2 height of the stabilization unit housing, and at least one stabilized crude oil outlet located at the bottom to 1 / 2 height of the stabilization unit housing, are used for contacting the crude oil to be stabilized with the carbon dioxide-containing material to carry out mass transfer exchange, and separating the stabilized crude oil and the carbon dioxide phase containing volatile components;

[0008] A light component recovery unit and / or oil reservoir connected to the outlet of the carbon dioxide phase containing volatile components, preferably the light component recovery unit includes at least one of a membrane gas separator, a cryogenic distillation separator, an adsorption separator, and an absorption separator, for recovering the carbon dioxide phase containing volatile components to obtain natural gas, condensate oil, and purified carbon dioxide.

[0009] A collection and transportation unit connected to the stabilized crude oil outlet is used for collecting and / or transporting the stabilized crude oil.

[0010] A first heat exchanger is used for heat exchange between the crude oil to be stabilized and the stabilized crude oil, and a second heat exchanger is used for heat exchange between the carbon dioxide phase containing volatile components and the carbon dioxide-containing material.

[0011] A third aspect of the present invention provides a method for stabilizing crude oil, the method being carried out in the apparatus described in the present invention, comprising:

[0012] (1) The crude oil to be stabilized and the stabilized crude oil are heat exchanged in the first heat exchanger and then injected into the stabilization unit through the crude oil inlet. The carbon dioxide-containing material and the carbon dioxide phase containing volatile components are heat exchanged in the second heat exchanger and then injected into the stabilization unit through the carbon dioxide-containing material inlet. The carbon dioxide-containing material and the crude oil to be stabilized are contacted in the stabilization unit and separated to obtain the stabilized crude oil and the carbon dioxide phase containing volatile components.

[0013] (2) The carbon dioxide phase containing volatile components is discharged from the volatile carbon dioxide phase outlet of the stabilization unit, and after heat exchange with the carbon dioxide-containing material in the second heat exchanger, it is sent to the light component recovery unit for recovery and processing to obtain natural gas, condensate oil and purified carbon dioxide, and / or

[0014] The carbon dioxide phase containing volatile components is discharged from the carbon dioxide phase outlet containing volatile components in the stabilization unit.

[0015] (3) The stabilized crude oil is output from the stabilized crude oil outlet of the stabilization unit, and after exchanging heat with the crude oil to be stabilized in the first heat exchanger, it is sent to the collection and / or transportation unit for the collection and / or transportation of the stabilized crude oil.

[0016] Through the above technical solution, the present invention has the following advantages:

[0017] This invention utilizes carbon dioxide to ensure a stable crude oil process and efficient utilization of gaseous components at lower temperatures and pressures, saving energy consumption, reducing carbon emissions, improving operational safety, reducing crude oil loss, and further enhancing safety in crude oil transportation. Attached Figure Description

[0018] Figure 1 This is a process flow diagram of a crude oil stabilization tower according to a preferred embodiment of the present invention.

[0019] Explanation of reference numerals in the attached figures

[0020] 1-Crude oil stabilization tower, 2-Tower tray, 3, 4-Centrifugal pump, 5, 6-Throttle valve, 7-First heat exchanger, 8-Second heat exchanger. Detailed Implementation

[0021] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0022] The first aspect of this invention provides a method for stabilizing crude oil, the method comprising:

[0023] The crude oil to be stabilized is brought into contact with a carbon dioxide-containing material for mass transfer exchange, and the stabilized crude oil and a carbon dioxide phase containing volatile components are separated.

[0024] This invention utilizes carbon dioxide to ensure a stable crude oil process and efficient utilization of gaseous components at lower temperatures and pressures, saving energy consumption, reducing carbon emissions, improving operational safety, reducing crude oil loss, and further enhancing safety in crude oil transportation.

[0025] In this invention, the contact conditions can be selected from a wide range. According to a preferred embodiment of this invention, the contact conditions include: a temperature of 20-150°C, preferably 20-100°C, more preferably 20-80°C; and / or a pressure of 0.1-10 MPa, preferably 0.1-5 MPa, more preferably 0.1-2 MPa.

[0026] According to a preferred embodiment of the present invention, the mass ratio of the crude oil to be stabilized to the carbon dioxide-containing material is 100:1-1:1, preferably 50:1-5:1. By adopting the aforementioned preferred scheme, energy consumption can be further saved, carbon emissions reduced, operational safety improved, crude oil loss reduced, and safety enhanced during crude oil transportation.

[0027] According to a preferred embodiment of the present invention, the carbon dioxide content in the carbon dioxide-containing material is not less than 80%, preferably not less than 90%.

[0028] According to a preferred embodiment of the present invention, the content of volatile components in the stabilized crude oil is 0-2 wt%, preferably 0-1 wt%, and more preferably 0-0.5 wt%.

[0029] According to a preferred embodiment of the present invention, the volatile component comprises C1-C4 hydrocarbon components, such as methane, ethane, propane, butane, etc.

[0030] According to a preferred embodiment of the present invention, the method further includes: performing phase separation treatment on the crude oil to be stabilized before contacting the carbon dioxide-containing material to initially remove the gas phase and water therein.

[0031] According to a preferred embodiment of the present invention, the method further includes: injecting a carbon dioxide phase containing volatile components into the reservoir to enhance oil recovery. The light components of crude oil can effectively reduce the miscibility pressure between carbon dioxide and crude oil, thereby significantly improving the oil displacement efficiency of carbon dioxide.

[0032] According to a preferred embodiment of the present invention, the method further includes: sending the carbon dioxide phase containing volatile components for recovery treatment to obtain natural gas, condensate oil, and purified carbon dioxide, preferably recycling the purified carbon dioxide back into the carbon dioxide-containing materials. By adopting the aforementioned preferred scheme, the recovery and utilization of light components and the recycling of carbon dioxide can be achieved.

[0033] A second aspect of the present invention provides a crude oil stabilization device, the device comprising:

[0034] A stabilization unit, and at least one carbon dioxide-containing material inlet located at the bottom to 1 / 2 height of the stabilization unit housing, at least one crude oil inlet located at 1 / 5-4 / 5 height of the stabilization unit housing, at least one carbon dioxide phase outlet containing volatile components located at the top to 1 / 2 height of the stabilization unit housing, and at least one stabilized crude oil outlet located at the bottom to 1 / 2 height of the stabilization unit housing, are used for contacting the crude oil to be stabilized with the carbon dioxide-containing material to carry out mass transfer exchange, and separating the stabilized crude oil and the carbon dioxide phase containing volatile components;

[0035] A light component recovery unit and / or oil reservoir connected to the outlet of the carbon dioxide phase containing volatile components, preferably the light component recovery unit includes at least one of a membrane gas separator, a cryogenic distillation separator, an adsorption separator, and an absorption separator, for recovering the carbon dioxide phase containing volatile components to obtain natural gas, condensate oil, and purified carbon dioxide.

[0036] A collection and transportation unit connected to the stabilized crude oil outlet is used for collecting and / or transporting the stabilized crude oil.

[0037] A first heat exchanger is used for heat exchange between the crude oil to be stabilized and the stabilized crude oil, and a second heat exchanger is used for heat exchange between the carbon dioxide phase containing volatile components and the carbon dioxide-containing material.

[0038] By employing the device of this invention, energy consumption can be further saved, carbon emissions reduced, operational safety improved, crude oil loss reduced, and safety enhanced during crude oil transportation.

[0039] According to a preferred embodiment of the present invention, the stabilizing unit includes at least one carbon dioxide-containing material inlet disposed at the bottom to 1 / 3 of the height of the stabilizing unit housing, preferably at the bottom to 1 / 4 of the height.

[0040] According to a preferred embodiment of the present invention, the stabilizing unit includes at least one crude oil inlet disposed at a height of 1 / 4-3 / 4, preferably 1 / 3-2 / 3, of the stabilizing unit housing.

[0041] According to a preferred embodiment of the present invention, the stabilizing unit includes at least one carbon dioxide phase outlet containing volatile components, disposed at the top to 2 / 3 of the height of the stabilizing unit housing, preferably at the top to 3 / 4 of the height.

[0042] According to a preferred embodiment of the present invention, the stabilizing unit includes at least one stable crude oil outlet disposed at the bottom to 1 / 3 of the height of the stabilizing unit housing, preferably at the bottom to 1 / 4 of the height.

[0043] According to a preferred embodiment of the present invention, the stabilizing unit includes a booster pump and valves disposed at each inlet and outlet.

[0044] In this invention, the stabilizing unit can be a conventional selection in the art. According to a preferred embodiment of this invention, the stabilizing unit is a stabilizing tower, which includes 2-50 tower plates arranged along the axial direction, preferably 5-40, and more preferably 10-30.

[0045] According to a preferred embodiment of the present invention, the tray includes at least one of a sieve tray, a bubble cap tray, a valve tray, a tongue-shaped tray, and a perforated tray; more preferably, it includes at least one of a sieve tray, a valve tray, and a perforated tray; and even more preferably, it includes at least one of a sieve tray and a perforated tray. By adopting the aforementioned preferred embodiments, energy consumption can be further saved, carbon emissions reduced, operational safety improved, crude oil loss reduced, and safety enhanced during crude oil transportation.

[0046] A third aspect of the present invention provides a method for stabilizing crude oil, the method being carried out in the apparatus described in the present invention, comprising:

[0047] (1) The crude oil to be stabilized and the stabilized crude oil are heat exchanged in the first heat exchanger and then injected into the stabilization unit through the crude oil inlet. The carbon dioxide-containing material and the carbon dioxide phase containing volatile components are heat exchanged in the second heat exchanger and then injected into the stabilization unit through the carbon dioxide-containing material inlet. The carbon dioxide-containing material and the crude oil to be stabilized are contacted in the stabilization unit and separated to obtain the stabilized crude oil and the carbon dioxide phase containing volatile components.

[0048] (2) The carbon dioxide phase containing volatile components is discharged from the volatile carbon dioxide phase outlet of the stabilization unit, and after heat exchange with the carbon dioxide-containing material in the second heat exchanger, it is sent to the light component recovery unit for recovery and processing to obtain natural gas, condensate oil and purified carbon dioxide, and / or

[0049] The carbon dioxide phase containing volatile components is discharged from the carbon dioxide phase outlet containing volatile components in the stabilization unit.

[0050] (3) The stabilized crude oil is output from the stabilized crude oil outlet of the stabilization unit, and after exchanging heat with the crude oil to be stabilized in the first heat exchanger, it is sent to the collection and / or transportation unit for the collection and / or transportation of the stabilized crude oil.

[0051] By employing the aforementioned method of the present invention, energy consumption can be further saved, carbon emissions reduced, operational safety improved, crude oil loss reduced, and safety enhanced during crude oil transportation.

[0052] In this invention, the injection flow rate of crude oil can be selected from a wide range. According to a preferred embodiment of this invention, the injection flow rate of crude oil is 5-5000 tons / day, preferably 20-2000 tons / day, and more preferably 50-1000 tons / day.

[0053] In this invention, the injection flow rate of the carbon dioxide-containing material can be selected within a wide range. According to a preferred embodiment of this invention, the injection flow rate of the carbon dioxide-containing material is 0.1-1000 tons / day, preferably 0.4-400 tons / day, and more preferably 1-200 tons / day.

[0054] The present invention will be described in detail below through examples. In the following examples, the mass fraction of each component was determined by chromatographic and mass spectrometric analysis methods.

[0055] Example 1

[0056] The composition of crude oil A after dehydration and degassing by the three-phase separator is shown in Table 1.

[0057] Table 1

[0058] C1 cut 0.07％ C12 cut 3.80％ C23 cut 3.16％ C2 cut 0.14％ C13 cut 4.25％ C24 cut 3.29％ C3 cut 0.44％ C14 cut 3.94％ C25 cut 3.43％ C4 cut 1.02％ C15 cut 3.63％ C26 cut 3.57％ C5 cut 1.90％ C16 cut 3.51％ C27 cut 3.70％ C6 cut 2.41％ C17 cut 3.50％ C28 cut 3.84％ C7 cut 3.97％ C18 cut 3.14％ C29 cut 3.98％ C8 cut 4.51％ C19 cut 2.13％ C30 cut 4.11％ C9 cut 3.79％ C20 cut 2.75％ C32 cut 4.39％ C10cut 2.81％ C21 cut 2.88％ C36 cut 4.93％ C11cut 4.01％ C22 cut 3.02％

[0059] The mass fraction of C1-C4 components in crude oil A is 1.66%.

[0060] The process flow diagram for crude oil stabilization using CO2 is as follows: Figure 1 As shown.

[0061] At 0.11 MPa, the crude oil to be stabilized exchanges heat with the stabilized crude oil in heat exchanger (7), increasing the temperature of the crude oil to be stabilized from 25°C to 42.5°C, while the temperature of the stabilized crude oil decreases from 50°C to 30°C. CO2 exchanges heat with the CO2 phase containing volatile components in heat exchanger (8), increasing the temperature from 25°C to 48°C, while the temperature of the CO2 phase containing volatile components decreases from 50°C to 33°C. After heat exchange, the crude oil to be stabilized and CO2 are kept at a constant temperature of 50°C by a heater (not shown in the figure) before entering the crude oil stabilization tower.

[0062] After stable start-up, the temperature and pressure of the crude oil stabilization tower were kept constant at 50℃ and 0.105MPa, respectively. Crude oil was injected into the stabilization tower via a centrifugal pump at a flow rate of 500 tons / day. CO2 was injected into the stabilization tower at a flow rate of 25 tons / day, controlled by a throttling valve. The stabilization tower contained 18 perforated trays with 10mm sieve diameters. The unstabilized crude oil inlet was on the 10th tray, and the CO2 inlet was below the 1st tray. The stabilized crude oil was discharged from the bottom of the tower via a centrifugal pump at a flow rate of 487 tons / day, while the CO2 phase, rich in volatile components, was discharged from the top of the tower via a throttling valve at a flow rate of 38 tons / day. The composition of the stabilized crude oil and the CO2 phase containing volatile components is shown in Table 2. The mass fraction of C1-C4 components in the stabilized crude oil was 0.40%, meeting the requirement of <0.5%. Moreover, the crude oil entering the CO2 phase accounted for only 2.79% of the total crude oil. Therefore, the CO2 crude oil stabilization method only resulted in a 2.79% crude oil loss. Compared to the positive pressure flash evaporation method (Comparative Example 1), crude oil loss was reduced by 47.7%. Furthermore, the stabilized crude oil contains 0.19% CO2. In the event of a leak in the gathering and transportation system, this CO2 will escape from the crude oil, temporarily isolating it from oxygen and diluting the concentration of flammable gases, further reducing the risk of fire and explosion. The stabilized crude oil enters the gathering and transportation system and is transported to the refinery via pipeline. The miscibility pressure of CO2 rich in volatile components with crude oil is lower than that of pure CO2; therefore, after compression, its injection into the reservoir can effectively improve the CO2 displacement efficiency.

[0063] Table 2

[0064]

[0065]

[0066] Using the method of this embodiment, C1-C4 components can be removed from crude oil at lower temperatures and pressures, achieving crude oil stabilization. Compared with the traditional positive pressure flash evaporation method (Comparative Example 1), the method of this embodiment reduces operating temperature and pressure, thereby saving energy consumption, improving process safety, increasing CO2 utilization, and reducing carbon emissions. Moreover, using the method of this embodiment can reduce crude oil loss by 47.7%. The small amount of CO2 dissolved in the stabilized crude oil can provide temporary isolation protection in the event of a leak during gathering and transportation, further improving the safety of gathering and transportation.

[0067] Example 2

[0068] The components of crude oil B are shown in Table 3.

[0069] Table 3

[0070] C1 cut 0.04％ C12 cut 3.94％ C23 cut 2.43％ C2 cut 0.31％ C13 cut 4.21％ C24 cut 2.54％ C3 cut 1.03％ C14 cut 4.00％ C25 cut 2.64％ C4 cut 1.60％ C15 cut 3.85％ C26 cut 2.75％ C5 cut 2.16％ C16 cut 3.25％ C27 cut 2.85％ C6 cut 3.09％ C17 cut 3.11％ C28 cut 2.96％ C7 cut 5.72％ C18 cut 3.21％ C29 cut 3.06％ C8 cut 7.59％ C19 cut 3.00％ C30 cut 3.17％ C9 cut 5.43％ C20 cut 2.12％ C32 cut 3.38％ C10cut 3.78％ C21 cut 2.22％ C36 cut 3.80％ C11cut 4.45％ C22 cut 2.33％

[0071] The mass fraction of C1-C4 components in crude oil B is 2.98%.

[0072] The process flow diagram for crude oil stabilization using CO2 is as follows: Figure 1 As shown.

[0073] At 0.11 MPa, the crude oil to be stabilized exchanges heat with the stabilized crude oil in heat exchanger (7), increasing the temperature of the crude oil to be stabilized from 25°C to 42°C, while decreasing the temperature of the stabilized crude oil from 50°C to 30°C. CO2 exchanges heat with the CO2 phase containing volatile components in heat exchanger (8), increasing the temperature from 25°C to 48.5°C, while decreasing the temperature of the CO2 phase containing volatile components from 50°C to 33°C. After heat exchange, the crude oil to be stabilized and CO2 are kept at a constant temperature of 50°C by a heater (not shown in the figure) before entering the crude oil stabilization tower.

[0074] After stable start-up, the temperature and pressure of the crude oil stabilization tower were kept constant at 50℃ and 0.105MPa, respectively. Crude oil was injected into the stabilization tower via a centrifugal pump at a flow rate of 500 tons / day. CO2 was injected into the stabilization tower at a flow rate of 50 tons / day, controlled by a throttling valve. The stabilization tower contained 20 perforated trays with 10mm sieve diameters. The unstabilized crude oil inlet was on the 10th tray, and the CO2 inlet was below the 1st tray. The stabilized crude oil was discharged from the bottom of the tower via a centrifugal pump at a flow rate of 473.2 tons / day, while the CO2 phase, rich in volatile components, was discharged from the top of the tower via a throttling valve at a flow rate of 76.8 tons / day. The composition of the stabilized crude oil and the CO2 phase containing volatile components is shown in Table 4. The mass fraction of C1-C4 components in the stabilized crude oil was 0.44%, meeting the requirement of <0.5%. Moreover, the crude oil entering the CO2 phase accounted for 5.56% of the total crude oil. Therefore, the CO2 crude oil stabilization method resulted in a 5.56% crude oil loss. Compared to the positive pressure flash evaporation method (Comparative Example 2), crude oil loss was reduced by 49.9%. Furthermore, the stabilized crude oil contains 0.21% CO2. In the event of a leak in the gathering and transportation system, this CO2 will escape from the crude oil, temporarily isolating it from oxygen and diluting the concentration of flammable gases, further reducing the risk of fire and explosion. The stabilized crude oil enters the gathering and transportation system and is transported to the refinery via pipeline. The miscibility pressure of CO2 rich in volatile components with crude oil is lower than that of pure CO2; therefore, after compression, its injection into the reservoir can effectively improve the CO2 displacement efficiency.

[0075] Table 4

[0076]

[0077]

[0078] Using the method of this embodiment, C1-C4 components can be removed from crude oil at lower temperatures and pressures, achieving crude oil stabilization. Compared with the traditional positive pressure flash evaporation method (Comparative Example 2), the method of this embodiment reduces operating temperature and pressure, thereby saving energy consumption, improving process safety, increasing CO2 utilization, and reducing carbon emissions. Moreover, using the method of this embodiment can reduce crude oil loss by 49.9%. The small amount of CO2 dissolved in the stabilized crude oil can provide temporary isolation protection in the event of a leak during gathering and transportation, further improving the safety of gathering and transportation.

[0079] Example 3

[0080] This embodiment is the same as Embodiment 2, except that CO2 rich in volatile components is injected into the membrane gas separator. Since the kinetic diameter of CO2 is smaller than that of the light components of crude oil, it can pass through the separation membrane to obtain purified CO2, while the light components of crude oil are blocked and thus purified and enriched to obtain natural gas and condensate products.

[0081] Comparative Example 1

[0082] Similar to Example 1, but using a positive pressure flash stabilization method at 150°C and 0.2 MPa, the resulting gas-liquid two-phase composition is shown in Table 5. After stabilization, the mass fraction of C1-C4 components in the crude oil decreased to 0.39%, meeting the requirement of <0.5%. However, the removed gas phase accounted for 5.34% of the total crude oil mass. Therefore, using the positive pressure flash stabilization method results in a 5.34% loss of crude oil, and it also requires energy consumption to heat the crude oil to 150°C.

[0083] Table 5

[0084]

[0085]

[0086] Comparative Example 2

[0087] Similar to Example 2, but using a positive pressure flash stabilization method at 150°C and 0.2 MPa, the resulting gas-liquid two-phase composition is shown in Table 6. After stabilization, the mass fraction of C1-C4 components in the crude oil decreased to 0.44%, meeting the requirement of <0.5%. However, the removed gas phase accounted for 11.09% of the total crude oil mass. Therefore, using the positive pressure flash stabilization method results in an 11.09% loss of crude oil, and it also requires energy consumption to heat the crude oil to 150°C.

[0088] Table 6

[0089]

[0090]

[0091] As can be seen from the results in Tables 1-6, Examples 1-3 using the scheme of the present invention have significantly better effects than Comparative Examples 1-2, and can save energy consumption, reduce carbon emissions, improve the safety of the operation process, reduce crude oil loss, and enhance the safety of crude oil transportation.

[0092] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for stabilizing crude oil, characterized in that, The method includes: The crude oil to be stabilized is brought into contact with a material containing carbon dioxide for mass transfer exchange, and the stabilized crude oil and a carbon dioxide phase containing volatile components are separated. The volatile component is a C1-C4 hydrocarbon component; The carbon dioxide content in the carbon dioxide-containing material is not less than 80%; The mass ratio of the crude oil to carbon dioxide-containing material to be stabilized is 50:1-5:1 (calculated as carbon dioxide). The contact conditions include: a temperature of 20-150℃ and a pressure of 0.1-2MPa; The crude oil stabilization method is carried out in a stabilization unit, which includes: A stabilization tower, and at least one carbon dioxide-containing material inlet located at the bottom to half the height of the stabilization tower shell, at least one crude oil inlet located at 1 / 5 to 4 / 5 the height of the stabilization tower shell, at least one carbon dioxide phase outlet containing volatile components located at the top to half the height of the stabilization tower shell, and at least one stabilized crude oil outlet located at the bottom to half the height of the stabilization tower shell, are used for contacting the crude oil to be stabilized with the carbon dioxide-containing material to carry out mass transfer exchange, and separating the stabilized crude oil and the carbon dioxide phase containing volatile components.

2. The method according to claim 1, wherein, The conditions for contact include: The temperature ranges from 20 to 100℃.

3. The method according to claim 2, wherein, The conditions for contact include: The temperature ranges from 20 to 80℃.

4. The method according to claim 1, wherein, The carbon dioxide content in the carbon dioxide-containing material is not less than 90%; and / or The content of volatile components in the stabilized crude oil is 0-2 wt%.

5. The method according to claim 4, wherein, The content of volatile components in the stabilized crude oil is 0-1 wt%.

6. The method according to claim 4, wherein, The content of volatile components in the stabilized crude oil is 0-0.5 wt%.

7. The method according to claim 1, wherein, The method further includes: performing phase separation treatment on the crude oil to be stabilized before contacting the carbon dioxide-containing material.

8. The method according to any one of claims 1-7, wherein, The method further includes: injecting a carbon dioxide phase containing volatile components into the reservoir to enhance oil recovery and / or sending it for recycling to obtain natural gas, condensate, and purified carbon dioxide.

9. The method according to claim 8, wherein, The purified carbon dioxide is recycled back into the carbon dioxide-containing materials.

10. The method according to claim 1, wherein, The stabilizing device includes: A light component recovery unit and / or oil reservoir connected to the outlet of the carbon dioxide phase containing volatile components are used for the recovery and treatment of the carbon dioxide phase containing volatile components to obtain natural gas, condensate oil and purified carbon dioxide. A collection and transportation unit connected to the stabilized crude oil outlet is used for collecting and / or transporting the stabilized crude oil. A first heat exchanger is used for heat exchange between the crude oil to be stabilized and the stabilized crude oil, and a second heat exchanger is used for heat exchange between the carbon dioxide phase containing volatile components and the carbon dioxide-containing material.

11. The method according to claim 10, wherein, The light component recovery unit includes at least one of a membrane gas separator, a cryogenic distillation separator, an adsorption separator, and an absorption separator.

12. The method according to claim 1, wherein, The stabilizing tower includes, At least one carbon dioxide-containing material inlet is located at the bottom to one-third of the height of the stabilizer shell; and / or At least one crude oil inlet is located at 1 / 4 to 3 / 4 of the height of the stabilizer tower shell; and / or At least one carbon dioxide phase outlet containing volatile components is provided at the top to 2 / 3 height of the stabilizer tower shell; and / or At least one stabilized crude oil outlet is provided at the bottom to one-third of the height of the stabilizer shell, and / or Booster pumps and valves are installed at each inlet and outlet.

13. The method according to claim 1, wherein, The stabilizing tower includes, At least one carbon dioxide-containing material inlet is located at the bottom to one-quarter height of the stabilizer shell; and / or At least one crude oil inlet is located at 1 / 3 to 2 / 3 of the height of the stabilizer tower shell; and / or At least one carbon dioxide phase outlet containing volatile components is provided at the top to 3 / 4 height of the stabilizer tower shell; and / or At least one stabilized crude oil outlet is provided at the bottom to 1 / 4 height of the stabilizer tower shell.

14. The method according to claim 1, wherein, The stabilizing tower includes 2-50 trays arranged along the axial direction.

15. The method according to claim 14, wherein, The number of trays is 5-40.

16. The method of claim 14, wherein, The number of trays is 10-30.

17. The method of claim 14, wherein, The tray includes at least one of the following: sieve tray, bubble cap tray, valve tray, tongue-shaped tray, and inclined hole tray.

18. The method according to claim 14, wherein, The tray includes at least one of sieve trays, valve trays, and inclined hole trays.

19. The method of claim 14, wherein, The trays include one or both of the following: perforated trays and slanted perforated trays.

20. The method according to claim 1, wherein, The crude oil injection flow rate is 5-5000 tons / day; The injection flow rate of the carbon dioxide-containing material is 0.1-1000 tons / day.

21. The method according to claim 1, wherein, The crude oil injection flow rate is 20-2000 tons / day; The injection flow rate of the carbon dioxide-containing material is 0.4-400 tons / day.

22. The method according to claim 1, wherein, The crude oil injection flow rate is 50-1000 tons / day; The injection flow rate of the carbon dioxide-containing material is 1-200 tons / day.

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