A composite purification system for removing sulfur, water and carbon dioxide contained in oilfield associated gas

Abstract

This utility model relates to a composite purification system for removing sulfur, water, and carbon dioxide from associated gas in oil fields. The system includes an associated gas inlet pipe and is characterized by: a primary absorption tower, a secondary absorption tower, a compressor, a nitrogen source, and a heater. Both the primary and secondary absorption towers are equipped with 13X molecular sieves and 4A molecular sieves. The compressor is installed on the associated gas inlet pipe. The two ends of the primary inlet pipe are connected to the top of the primary absorption tower and the associated gas inlet pipe, respectively. A primary valve is installed on the primary inlet pipe. One end of a primary vent pipe is connected to the primary inlet pipe and is located near the top of the primary absorption tower. A secondary valve is installed on the primary vent pipe. A primary outlet pipe is connected to the bottom of the primary absorption tower. A sixth valve is installed on the primary outlet pipe. The nitrogen inlet pipe is connected to the nitrogen source, and the heater is installed on the nitrogen inlet pipe and located near the nitrogen source. This utility model has a simple structure, low cost, and is easy to move.

Description

Technical Field

[0001] This utility model relates to a composite purification system for removing sulfur, water and carbon dioxide from associated gas in oil fields. It belongs to the chemical industry and is used in the recovery of associated gas in oil fields. Background Technology

[0002] During oil extraction, a gas rich in hydrocarbons such as methane, ethane, and propane is produced, commonly known as oilfield vented air or associated gas. This gas is actually a valuable resource with recovery and reuse potential. However, because oilfield vented air is widely distributed, its volume is small, and its fluctuations are significant, using conventional pipeline transportation methods for recovery and treatment would face high investment costs and poor economic viability. Therefore, currently, most oilfield vented air is often directly vented and burned. This practice not only results in a huge waste of resources but also pollutes the environment, failing to meet national production safety and environmental protection requirements.

[0003] Currently, there are related recovery systems designed both domestically and internationally for the recovery and utilization of vented air from oil fields. However, these systems have high investment costs, require multiple units such as dehydration, deacidification, and desulfurization, are highly complex, and cannot be easily moved. Utility Model Content

[0004] The purpose of this invention is to overcome the above-mentioned shortcomings in the existing technology and to provide a composite purification system for removing sulfur, water and carbon dioxide contained in associated gas from oil fields that has a reasonable structural design and is easy to move.

[0005] The technical solution adopted by this utility model to solve the above problems is as follows: The composite purification system for removing sulfur, water and carbon dioxide contained in associated gas from oil fields includes an associated gas input pipe for connecting to the associated gas source of the oil field. Its structural features include: a No. 1 absorption tower, a No. 2 absorption tower, a No. 1 valve, a No. 2 valve, a No. 3 valve, a No. 4 valve, a No. 5 valve, a No. 6 valve, a No. 7 valve, a No. 8 valve, a compressor, a nitrogen source, a heater, a No. 1 input pipe, a No. 2 input pipe, a No. 1 output pipe, a No. 2 output pipe, and a nitrogen source. The system includes an input pipe, a first nitrogen pipe, a second nitrogen pipe, a first vent pipe, and a second vent pipe. Both the first and second absorption towers are equipped with 13X molecular sieves and 4A molecular sieves. The compressor is installed on the associated gas input pipe and close to the associated gas source. The two ends of the first input pipe are connected to the top of the first absorption tower and the associated gas input pipe, respectively. A first valve is installed on the first input pipe. The two ends of the second input pipe are connected to the top of the second absorption tower and the associated gas input pipe, respectively. Valve No. 1 is installed on Inlet Pipe No. 2. One end of Vent Pipe No. 1 is connected to Inlet Pipe No. 1 and is near the top of Absorber Tower No. 1. Valve No. 2 is installed on Vent Pipe No. 1. One end of Vent Pipe No. 2 is connected to Inlet Pipe No. 2 and is near the top of Absorber Tower No. 2. Valve No. 4 is installed on Vent Pipe No. 2. Outlet Pipe No. 1 is connected to the bottom of Absorber Tower No. 1. Valve No. 6 is installed on Outlet Pipe No. 1. Outlet Pipe No. 2 is installed at the bottom of Absorber Tower No. 2. Valve No. 8 is installed on Outlet Pipe No. 2. The nitrogen input pipe is connected to the nitrogen source. The heater is installed on the nitrogen input pipe and close to the nitrogen source. One end of the first nitrogen pipe is connected to the nitrogen input pipe, and the other end of the first nitrogen pipe is connected to the first output pipe and close to the bottom of the first absorption tower. The fifth valve is installed on the first nitrogen pipe. One end of the second nitrogen pipe is connected to the nitrogen input pipe, and the other end of the second nitrogen pipe is connected to the second output pipe and close to the bottom of the second absorption tower. The seventh valve is installed on the second nitrogen pipe.

[0006] Preferably, the present invention also includes a main vent pipe, wherein both the first vent pipe and the second vent pipe are connected to the main vent pipe.

[0007] Preferably, the present invention also includes a subsequent liquefaction process pipe, wherein both the first output pipe and the second output pipe are connected to the subsequent liquefaction process pipe.

[0008] Preferably, the present invention uses 13X molecular sieve and 4A molecular sieve located in the No. 1 absorption tower, with the 13X molecular sieve positioned above the 4A molecular sieve.

[0009] Preferably, the present invention uses 13X molecular sieve and 4A molecular sieve located in the No. 2 absorption tower, with the 13X molecular sieve positioned above the 4A molecular sieve.

[0010] Compared with the prior art, this utility model has the following advantages and effects: simple structure, reasonable design, only two absorption towers are needed to complete the absorption of carbon dioxide, water and sulfur contained in associated gas in oil fields, high integration, and easy to move. For example, it can be placed on a skid, making it flexible and convenient to use, with low cost and good economic efficiency. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of this utility model and / or the prior art, the drawings used in the description of the embodiments and / or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a schematic diagram of the structure of the composite purification system for removing sulfur, water and carbon dioxide contained in associated gas from oil fields, as described in this utility model embodiment.

[0013] In the diagram: 1-Valve No. 1; 2-Valve No. 2; 3-Valve No. 3; 4-Valve No. 4; 5-Valve No. 5; 6-Valve No. 6; 7-Valve No. 7; 8-Valve No. 8; 9-Associated gas source from the oilfield; 10-Compressor; 11-Nitrogen source; 12-Heater; 13-Associated gas input pipe from the oilfield; 14-Input pipe No. 1; 15-Input pipe No. 2; 16-Output pipe No. 1; 17-Output pipe No. 2; 18-Nitrogen input pipe; 19-Nitrogen pipe No. 1; 20-Nitrogen pipe No. 2; 21-Vent pipe No. 1; 22-Vent pipe No. 2; 23-Main vent pipe; 24-Subsequent liquefaction process pipe; T1-Absorber No. 1; T2-Absorber No. 2; F1-13X molecular sieve; F2-4A molecular sieve. Detailed Implementation

[0014] The present invention will be further described in detail below with reference to the accompanying drawings and through embodiments. The following embodiments are explanations of the present invention, but the present invention is not limited to the following embodiments.

[0015] Example

[0016] See Figure 1The composite purification system for removing sulfur, water, and carbon dioxide from associated gas in this embodiment includes an associated gas input pipe 13 connected to the associated gas source 9, an absorption tower T1, an absorption tower T2, valves 1, 2, 3, 4, 5, 6, 7, and 8, a compressor 10, a nitrogen source 11, a heater 12, an input pipe 14, an input pipe 15, an output pipe 16, an output pipe 17, a nitrogen input pipe 18, a nitrogen pipe 19, a nitrogen pipe 20, a vent pipe 21, a vent pipe 22, a main vent pipe 23, and a subsequent liquefaction process pipe 24.

[0017] In this embodiment, both absorption tower T1 (No. 1) and absorption tower T2 are equipped with 13X molecular sieve F1 and 4A molecular sieve F2. In absorption tower T1, 13X molecular sieve F1 is positioned above 4A molecular sieve F2. Similarly, in absorption tower T2, 13X molecular sieve F1 is positioned above 4A molecular sieve F2.

[0018] In this embodiment, the compressor 10 is installed on the associated gas input pipe 13 and close to the associated gas source 9. The two ends of the first input pipe 14 are respectively connected to the top of the first absorption tower T1 and the associated gas input pipe 13. The first valve 1 is installed on the first input pipe 14. The two ends of the second input pipe 15 are respectively connected to the top of the second absorption tower T2 and the associated gas input pipe 13. The third valve 3 is installed on the second input pipe 15.

[0019] In this embodiment, one end of the first vent pipe 21 is connected to the first input pipe 14 and is close to the top of the first absorption tower T1. The second valve 2 is installed on the first vent pipe 21. One end of the second vent pipe 22 is connected to the second input pipe 15 and is close to the top of the second absorption tower T2. The fourth valve 4 is installed on the second vent pipe 22. Both the first vent pipe 21 and the second vent pipe 22 are connected to the main vent pipe 23.

[0020] In this embodiment, the first output pipe 16 is connected to the bottom of the first absorption tower T1, the sixth valve 6 is installed on the first output pipe 16, the second output pipe 17 is installed at the bottom of the second absorption tower T2, the eighth valve 8 is installed on the second output pipe 17, and both the first output pipe 16 and the second output pipe 17 are connected to the subsequent liquefaction process pipe 24.

[0021] In this embodiment, the nitrogen input pipe 18 is connected to the nitrogen source 11. The heater 12 is installed on the nitrogen input pipe 18 and close to the nitrogen source 11. One end of the first nitrogen pipe 19 is connected to the nitrogen input pipe 18, and the other end of the first nitrogen pipe 19 is connected to the first output pipe 16 and close to the bottom of the first absorption tower T1. The fifth valve 5 is installed on the first nitrogen pipe 19. One end of the second nitrogen pipe 20 is connected to the nitrogen input pipe 18, and the other end of the second nitrogen pipe 20 is connected to the second output pipe 17 and close to the bottom of the second absorption tower T2. The seventh valve 7 is installed on the second nitrogen pipe 20.

[0022] In this embodiment, the upper layer of absorption tower T1 and absorption tower T2 is filled with 13X molecular sieve F1 for the absorption of carbon dioxide and hydrogen sulfide; the lower layer is filled with 4A molecular sieve F2 for dehydration.

[0023] The operation process of the composite purification system for removing sulfur, water and carbon dioxide from associated gas in oil fields in this embodiment is as follows.

[0024] 1. The associated gas in the associated gas source 9 of the oilfield is pre-pressurized by the compressor 10 and then enters the first absorption tower T1 through valve 1. At this time, valves 2 and 5 are both closed.

[0025] 2. The associated gas enters the No. 1 absorption tower T1 and passes through 13X molecular sieve F1 and 4A molecular sieve F2 in sequence. After passing through 13X molecular sieve F1, carbon dioxide and hydrogen sulfide are removed; after passing through 4A molecular sieve F2, water is removed.

[0026] 3. The associated gas purified by the No. 1 absorption tower T1 passes through the No. 6 valve 6 and then enters the subsequent liquefaction process through the subsequent liquefaction process pipe 24.

[0027] 4. When absorption tower T1 is in operation, absorption tower T2 is in regeneration. At this time, valves 8 and 3 are closed, while valves 7 and 4 are open.

[0028] 5. The nitrogen in nitrogen source 11 is heated by heater 12 and then enters the second absorption tower T2 through valve 7. The heated nitrogen carries away the carbon dioxide, hydrogen sulfide and water absorbed in the second absorption tower T2. Then it passes through valve 4 and is discharged to the outside through the main vent pipe 23.

[0029] 6. After the regeneration of the second absorption tower T2 is completed, turn off the heater 12 and continue to introduce nitrogen gas at room temperature into the second absorption tower T2 to cool it.

[0030] 7. After the second absorption tower T2 has cooled down, it has completed its regeneration and then begins absorption. The absorption method is the same as that of the first absorption tower T1.

[0031] 8. When absorption tower T2 is performing absorption, absorption tower T1 begins regeneration, and the regeneration method is the same as that for absorption tower T2.

[0032] Associated gas from the oilfield is purified through absorption towers T1 and T2 to obtain deacidified, dehydrated, and desulfurized natural gas, which can then be liquefied, stored, or transported for further liquefaction. This is because if the associated gas from the oilfield has not undergone deacidification, dehydration, and desulfurization treatment, subsequent liquefaction may result in freezing blockages or corrosion of containers and pipelines.

[0033] Furthermore, it should be noted that the specific embodiments described in this specification may differ in the shape and name of their components. The above description is merely illustrative of the structure of this utility model. All equivalent or simple variations made based on the structure, features, and principles described in this utility model patent concept are included within the protection scope of this utility model patent. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to replace them, as long as they do not deviate from the structure of this utility model or exceed the scope defined in these claims, all of which should fall within the protection scope of this utility model.

Claims

1. A composite purification system for removing sulfur, water, and carbon dioxide from associated gas in oil fields, comprising an associated gas inlet pipe (13) for connecting to an associated gas source (9), characterized in that: It also includes Absorption Tower No. 1 (T1), Absorption Tower No. 2 (T2), Valve No. 1 (1), Valve No. 2 (2), Valve No. 3 (3), Valve No. 4 (4), Valve No. 5 (5), Valve No. 6 (6), Valve No. 7 (7), Valve No. 8 (8), Compressor (10), Nitrogen Source (11), Heater (12), Input Pipe No. 1 (14), Input Pipe No. 2 (15), Output Pipe No. 1 (16), Output Pipe No. 2 (17), Nitrogen Input Pipe (18), Nitrogen Pipe No. 1 (19), Nitrogen Pipe No. 2 (20), Vent Pipe No. 1 (21), and Vent Pipe No. 2 (22). Both Absorption Tower No. 1 (T1) and Absorption Tower No. 2 (T2) contain... The system is equipped with 13X molecular sieve (F1) and 4A molecular sieve (F2). The compressor (10) is installed on the associated gas input pipe (13) and close to the associated gas source (9). The two ends of the first input pipe (14) are respectively connected to the top of the first absorption tower (T1) and the associated gas input pipe (13). The first valve (1) is installed on the first input pipe (14). The two ends of the second input pipe (15) are respectively connected to the top of the second absorption tower (T2) and the associated gas input pipe (13). The third valve (3) is installed on the second input pipe (15). One end of the first vent pipe (21) is connected to the first input pipe (14). The first absorption tower (T1) is located on the top of the first vent pipe (21), and the second valve (22) is installed on the first vent pipe (21). One end of the second vent pipe (22) is connected to the second input pipe (15) and is located near the top of the second absorption tower (T2). The fourth valve (4) is installed on the second vent pipe (22). The first output pipe (16) is connected to the bottom of the first absorption tower (T1). The sixth valve (6) is installed on the first output pipe (16). The second output pipe (17) is installed at the bottom of the second absorption tower (T2). The eighth valve (8) is installed on the second output pipe (17). The nitrogen input pipe (18) and the nitrogen source (11) are connected to the first vent pipe (21). The heater (12) is installed on the nitrogen input pipe (18) and close to the nitrogen source (11). One end of the first nitrogen pipe (19) is connected to the nitrogen input pipe (18), and the other end of the first nitrogen pipe (19) is connected to the first output pipe (16) and close to the bottom of the first absorption tower (T1). The fifth valve (5) is installed on the first nitrogen pipe (19). One end of the second nitrogen pipe (20) is connected to the nitrogen input pipe (18), and the other end of the second nitrogen pipe (20) is connected to the second output pipe (17) and close to the bottom of the second absorption tower (T2). The seventh valve (7) is installed on the second nitrogen pipe (20).

2. The composite purification system for removing sulfur, water, and carbon dioxide from associated gas in oil fields according to claim 1, characterized in that: It also includes a main vent pipe (23), wherein the first vent pipe (21) and the second vent pipe (22) are both connected to the main vent pipe (23).

3. The composite purification system for removing sulfur, water, and carbon dioxide from associated gas in oil fields according to claim 1, characterized in that: It also includes a subsequent liquefaction process pipe (24), wherein the first output pipe (16) and the second output pipe (17) are both connected to the subsequent liquefaction process pipe (24).

4. The composite purification system for removing sulfur, water, and carbon dioxide from associated gas in oil fields according to claim 1, characterized in that: The 13X molecular sieve (F1) and 4A molecular sieve (F2) are located in the No. 1 absorption tower (T1), with the 13X molecular sieve (F1) located above the 4A molecular sieve (F2).

5. The composite purification system for removing sulfur, water, and carbon dioxide from associated gas in oil fields according to claim 1, characterized in that: The 13X molecular sieve (F1) and 4A molecular sieve (F2) are located in the second absorption tower (T2), with the 13X molecular sieve (F1) located above the 4A molecular sieve (F2).

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