Treatment system and treatment method for gathering and transporting crude oil and crude oil associated gas

Abstract

The invention relates to the field of oil-gas gathering and transportation of oil fields, and discloses a processing system and a processing method for gathering and transportation of crude oil and crude oil associated gas. The system comprises: a pre-water separation unit; a demulsification and heating reaction unit; a three-phase separation unit; the dehydration heat exchange mixing transportation unit comprises an in-station water mixing pipeline connected with a sewage outlet of the three-phase separation unit and an in-station sewage treatment pipeline connected with a free water outlet of the pre-water-separation separation unit; wherein the in-station sewage treatment pipeline is connected with the in-station water mixing pipeline through the water outlet and water mixing pipeline of the pre-water-separation separator; the water mixing unit is used for enabling part or all of free water separated by the water pre-separation unit to enter a water mixing pipeline through a water pre-separation separator, and enabling the free water to enter the in-station water mixing pipeline to be mixed with the sewage separated by the three-phase separation unit for heat exchange and heating to obtain heated sewage; and the heated sewage is externally conveyed to the wellhead of the oil well through an in-station watering pipeline for watering to obtain in-station liquid.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas gathering and transportation in oil fields, and in particular to a processing system and method for gathering and transportation of crude oil and crude oil associated gas. Background Art

[0002] After the oil produced fluid is produced by the pumping unit, it is collected and transported to the oil field centralized processing station through the transmission pipeline. The oil field centralized processing station will perform preliminary separation and processing of the oil, water and gas in the oil produced fluid, and then store or transport (external payment). The production links of the oil and gas gathering and processing process are roughly divided into: (1) well metering (2) single well gathering and gas gathering (3) oil, gas and water separation (4) crude oil dehydration, stabilization and storage (5) natural gas dehydration, light hydrocarbon recovery and hydrocarbon liquid storage (6) oil and gas transportation.

[0003] If the oil and gas gathering and transportation system is divided into four processes: gathering and transportation, dehydration, stabilization, and storage and transportation, according to the current statistical analysis of energy consumption in gathering and transportation production, the gathering and transportation energy consumption in these four processes accounts for about 60% to 80% of the total energy consumption of oil and gas gathering and transportation. At present, the crude oil settling tank is dehydrated and heated by a heating furnace, and then pumped and pressurized by a pump to be transported to the wellhead of the oil well through a water-mixing pipeline. The produced liquid is mixed with water, which is the mainstream water-mixing gathering and transportation method in the crude oil mixing process. However, this gathering and transportation method consumes a lot of energy, and the cost of crude oil in the centralized processing station of the oil field is high. As the development of the oil field enters the middle and late stages, the output of the oil field increases sharply, and the water content continues to rise. The centralized processing station of the oil field will consume more energy, and the overall income of the oil field will be seriously affected. Summary of the invention

[0004] The purpose of the present invention is to overcome the problem of huge energy consumption in the collection and transportation of crude oil output liquid mixed with water and treated at the centralized processing station in the middle and late stages of oil field development, and to provide a processing system and method for the collection and transportation of crude oil and associated gas. The system is suitable for the centralized treatment of crude oil output liquid in the late stage of oil field development, can save the cost during production operation, effectively adapt to the fluctuation of the output liquid volume of any oil field, and the treatment method of the system of the present invention can meet the safety and environmental protection requirements and improve the benefits of oil field development.

[0005] A first aspect of the present invention provides a processing system for gathering and transporting crude oil and crude oil associated gas, the system comprising:

[0006] The pre-water separation unit is used for the preliminary separation of oil, water and gas from the incoming liquid, and separates the crude oil saturated water mixture, crude oil associated gas A and most of the free water;

[0007] A demulsification and heating reaction unit, used for mixing and demulsifying a crude oil saturated water mixture with a demulsifier to obtain a mixed demulsified liquid, and heating the mixed demulsified liquid to obtain a heated mixed demulsified liquid;

[0008] A three-phase separation unit is used to separate the oil, gas and water three-phases of the heated mixed demulsified liquid to obtain purified crude oil, crude oil associated gas B and sewage;

[0009] The dehydration heat exchange blending unit includes an in-station water blending pipeline connected to the sewage outlet of the three-phase separation unit, and an in-station sewage treatment pipeline connected to the free water outlet of the pre-water separation unit;

[0010] Among them, the sewage treatment pipeline in the station is connected with the water injection pipeline in the station through the water inlet and outlet pipe of the pre-water separation separator, which is used to allow part or all of the free water separated by the pre-water separation unit to enter the water injection pipeline in the station through the water inlet and outlet pipe of the pre-water separation separator to mix with the sewage separated by the three-phase separation unit for heat exchange and temperature rise to obtain heated sewage. The heated sewage is transported to the wellhead of the oil well through the water injection pipeline in the station to be injected with water to obtain the incoming liquid.

[0011] A second aspect of the present invention provides a method for processing crude oil and crude oil associated gas gathering and transportation, the method is carried out in the system described in the present invention, the method comprising:

[0012] S1 Crude oil treatment: The incoming liquid is preliminarily separated into oil, water and gas in the pre-water separation unit to obtain crude oil saturated water mixed liquid, crude oil associated gas A and most of the free water. The separated crude oil saturated water mixed liquid enters the demulsification and heating reaction unit to mix and demulsify with the demulsifier to obtain a mixed demulsified liquid. The mixed demulsified liquid is heated in the demulsification and heating reaction unit and then enters the three-phase separation unit. The heated mixed demulsified liquid is then separated into oil, gas and water in the three-phase separation unit to obtain purified crude oil, crude oil associated gas B and sewage.

[0013] S2 Dehydration, heat exchange, blending and sewage treatment: Most of the free water separated by the pre-water separation unit enters the sewage treatment pipeline in the station, and the sewage separated by the three-phase separation unit enters the water blending pipeline in the station. After that, part or all of the free water separated by the pre-water separation unit enters the water blending pipeline in the station through the water inlet pipeline of the pre-water separator to mix with the sewage for heat exchange and temperature rise to obtain heated sewage. The heated sewage is transported to the wellhead of the oil well through the water blending pipeline in the station to be blended with water to obtain the incoming liquid.

[0014] Compared with the prior art, the present invention has at least the following beneficial effects:

[0015] (1) The present invention provides a system for collecting, transporting and processing crude oil output liquid and associated gas in the later stage of oil field development, wherein a pre-water separation unit first separates a large amount of free water and then enters a demulsification and heating reaction unit, which can significantly reduce the heating load of the heating furnace in the station. At the same time, the free water separated by the pre-water separation unit is effectively mixed with the high-temperature sewage removed by the downstream three-phase separation unit for heat exchange, and after being heated, it enters the water injection pipeline and enters the wellhead of each oil well for water injection, thereby avoiding the secondary heating loss of the water injected into the water injection heating furnace for heating in the settling tank of the traditional joint station. The energy consumption of crude oil processing in the oil field centralized processing station can be effectively reduced, and low-cost operation can be achieved. At the same time, the free water separated by the pre-water separation unit and the high-temperature sewage removed by the downstream three-phase separation unit are fully exchanged with each other in the pipeline, which also reduces the heating time of the water injection heating furnace in the traditional joint station, thereby improving the water injection efficiency of the oil well.

[0016] (2) The crude oil processing method in the station is simple and has eliminated the design of crude oil settling tanks in traditional joint stations, greatly reducing construction investment. The crude oil associated gas processing process is complete and can meet the effective utilization of crude oil associated gas under different demands, avoiding the high investment and high energy consumption of the complicated equipment process of traditional crude oil gathering and processing methods, saving production and operation costs. It can effectively adapt to the fluctuations in the output liquid volume of any oil field, while meeting safety and environmental protection requirements and improving the benefits of oil field development. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of a processing system for gathering and transporting crude oil and crude oil associated gas according to one embodiment of the present invention;

[0018] Figure 2 It is a schematic diagram of the existing crude oil and crude oil associated gas gathering and transportation processing system in Comparative Example 1;

[0019] Figure 3 It is a schematic diagram of the existing crude oil and crude oil associated gas gathering and transportation processing system in Example 2.

[0020] Description of Reference Numerals

[0021] 1. Pre-water separator 2. Safety valve

[0022] 3. Pre-water separator outlet valve 4. Coil heating furnace

[0023] 5. Three-phase separator water injection valve 6. Three-phase separator

[0024] 7. Three-phase separator outlet valve 8. Natural gas deoiler

[0025] 9. Natural gas cyclone separator 10. Natural gas compressor pry open fault vent valve

[0026] 11. Natural gas compressor skid 12. Natural gas water distributor

[0027] 13. Gas pipeline for internal use within the station 14. Venting pipeline within the station

[0028] 15. Dosing pipeline in the station 16. Water outlet valve of pre-water separator

[0029] 17. Valve for pre-water separator to enter heating furnace 18. Sewage pipe in the station

[0030] 19. Wastewater treatment pipeline within the station 20. Oil outlet valve of three-phase separator

[0031] 21. Valve for the water outlet and water inlet pipe of the pre-water separator

[0032] 22. Water mixing pipeline within the station 23. Purification oil tank

[0033] 24. Pre-water separator sewage pipe valve DETAILED DESCRIPTION

[0034] The endpoints and any values ​​of the ranges disclosed in this article 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 each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0035] Figure 1 This is one of the schematic diagrams of the crude oil and crude oil associated gas gathering and transportation processing system provided by the present invention. The schematic diagrams of other types of systems described in the specification are no longer listed separately, and the relevant embodiments are also listed as Figure 1 For example. Figure 1 As shown, the first aspect of the present invention provides a processing system for gathering and transporting crude oil and crude oil associated gas, the system comprising:

[0036] The pre-water separation unit is used for the preliminary separation of oil, water and gas from the incoming liquid to obtain crude oil saturated water mixed liquid, crude oil associated gas A and free water;

[0037] A demulsification and heating reaction unit, used for mixing and demulsifying a crude oil saturated water mixture with a demulsifier to obtain a mixed demulsified liquid, and heating the mixed demulsified liquid to obtain a heated mixed demulsified liquid;

[0038] A three-phase separation unit is used to separate the oil, gas and water three-phases of the heated mixed demulsified liquid to obtain purified crude oil, crude oil associated gas B and sewage;

[0039] The dehydration heat exchange blending unit includes an in-station water blending pipeline 22 connected to the sewage outlet of the three-phase separation unit, and an in-station sewage treatment pipeline 19 connected to the free water outlet of the pre-water separation unit;

[0040] Among them, the in-station sewage treatment pipeline 19 is connected to the in-station water injection pipeline 22 through the pre-water separation separator outlet water injection pipeline, which is used to allow part or all of the free water separated by the pre-water separation unit to enter the in-station water injection pipeline 22 through the pre-water separation separator outlet water injection pipeline to mix with the sewage separated by the three-phase separation unit for heat exchange and heating to obtain heated sewage. The heated sewage is transported to the wellhead of the oil well through the in-station water injection pipeline 22 to be injected with water to obtain the incoming liquid.

[0041] In the present invention, by combining the dehydration, heat exchange and blending unit, the pre-water separation unit, the demulsification, the heating reaction unit and the three-phase separation unit in the system, the daily energy consumption of the oilfield centralized processing station can be reduced while ensuring the normal operation of the oilfield gathering and processing system, meeting the safety and environmental protection requirements and improving the economic benefits of the later stage of oilfield development.

[0042] In the present invention, it can be understood by those skilled in the art that the incoming liquid is obtained by water of a certain temperature entering the water-injection network and being transported to the wellhead of the oil well for water-injection. In the present invention, the heated sewage can be pressurized by a water-injection pump and then enter the water-injection network and be transported to the wellhead of the oil well for water-injection and collection. The water-injection network is a conventional system in the field and will not be elaborated in the present invention. According to the present invention, in some preferred embodiments, a pre-water-dividing separator outlet and water-injection pipeline valve 21 is provided on the pre-water-dividing separator outlet and water-injection pipeline. By adopting the aforementioned embodiment, all or part of the free water from the pre-water-dividing separation unit can be mixed with the sewage separated by the three-phase separation unit for heat exchange and temperature increase as needed. When only part of the free water is mixed with the sewage separated by the three-phase separation unit for heat exchange and temperature increase, the other part of the free water can be used as sewage and enter the downstream sewage treatment system.

[0043] According to the present invention, a flow detection instrument can be set on the pre-water separation separator outlet water inlet pipe as needed to measure the amount of free water separated by the pre-water separation unit entering the station water inlet pipe 22, so as to adjust the opening of the pre-water separation separator outlet water inlet pipe valve 21.

[0044] According to the present invention, in some embodiments, the pre-water separation unit comprises a pre-water separation separator 1 .

[0045] In the present invention, it can be understood that the function of the pre-water separator 1 is to perform preliminary oil, water and gas separation on the incoming liquid. As long as the purpose of the present invention can be achieved, the structure of the pre-water separator 1 is not particularly limited. In some preferred embodiments, the pre-water separator 1 is a three-phase separation device, which has an oil-water chamber and a water chamber.

[0046] In the present invention, the three-phase separation device refers to a device that can separate the oil, gas and water in a fluid. The specific structure of the device is not limited and can be a conventional three-phase separator structure in the art.

[0047] According to the present invention, in some embodiments, the demulsification and heating reaction unit includes a heating furnace.

[0048] In the present invention, as long as the purpose of the present invention can be achieved, the form of the heating furnace is not particularly limited. In some embodiments, the heating furnace is a coil-type heating furnace 4.

[0049] In the present invention, compared with the prior art, the system of the present invention can save at least one set of heating furnaces, and at the same time can make the purified crude oil meet the requirement of water content lower than 0.5wt%.

[0050] According to the present invention, in some embodiments, the three-phase separation unit comprises a three-phase separator 6. By adopting the above-mentioned embodiment, the consumption of natural gas used for system heating can be saved as much as possible.

[0051] According to the present invention, in some embodiments, the sewage outlet of the three-phase separation unit is provided with a three-phase separator water injection valve 5. In the above embodiment, the sewage separated by the three-phase separator unit enters the water injection pipeline 22 in the station through the three-phase separator water injection valve 5.

[0052] According to the present invention, in order to conveniently control the outflow of free water in the pre-water separation unit, in some preferred embodiments, the system of the present invention also includes a free water flow interlocking control subsystem, which is used to interlock the outflow flow of free water in the pre-water separation unit.

[0053] According to the present invention, in some embodiments, the free water flow interlocking control subsystem includes a pre-water separation separator outlet valve 16 arranged at the free water outlet of the pre-water separation unit, and the pre-water separation separator outlet valve 16 is interlocked with the outlet flow of the pre-water separation unit, and the valve opening is automatically controlled by setting the outlet flow. With the aforementioned embodiment, the free water separated in the pre-water separation unit can pass through the sewage treatment pipeline 19 in the station, and enter the water mixing pipeline 22 in the station through the pre-water separation separator outlet water mixing pipeline to mix with the sewage separated by the three-phase separation unit for heat exchange and temperature increase; or enter the sewage treatment pipeline 19 in the station to the sewage treatment system in the station as sewage discharge treatment as needed.

[0054] According to the present invention, in some embodiments, the system of the present invention further comprises a crude oil level interlocking subsystem, which is used for the crude oil saturated water mixture to enter the demulsification and heating reaction unit when reaching the set liquid level, and for the purified crude oil to be led out of the three-phase separation unit when reaching the set liquid level.

[0055] According to the present invention, in some preferred embodiments, the crude oil level interlocking subsystem includes a pre-water separation separator inlet valve 17 provided at the crude oil saturated water mixed liquid outlet of the pre-water separation unit, and the pre-water separation separator inlet valve 17 is automatically interlocked with the liquid level of the pre-water separation unit. When the pre-water separation unit reaches the set liquid level, the separated crude oil saturated water mixed liquid passes through the pre-water separation unit and enters the demulsification and heating reaction unit, and includes a three-phase separator oil outlet valve 20 provided at the purified crude oil outlet of the three-phase separation unit, and the three-phase separator oil outlet valve 20 is automatically interlocked with the liquid level of the three-phase separation unit. When the liquid volume in the oil chamber of the three-phase separation unit reaches the set liquid level, the separated purified crude oil is led out of the three-phase separation unit.

[0056] According to the present invention, in some embodiments, the system of the present invention further comprises a crude oil associated gas processing unit for removing oil and water from the crude oil associated gas A and the crude oil associated gas B to obtain natural gas.

[0057] According to the present invention, in some preferred embodiments, along the material flow direction, the crude oil associated gas processing unit includes a natural gas deoiling sub-unit respectively connected to the crude oil associated gas A outlet of the pre-water separation unit and the crude oil associated gas B outlet of the three-phase separation unit, as well as a natural gas station self-use sub-unit and a natural gas export sub-unit each independently connected to the outlet of the natural gas deoiling sub-unit.

[0058] In the system of the present invention, a part of the natural gas can be selected as needed to be used by gas-consuming equipment within the station, and the other part can be exported.

[0059] According to the present invention, the purpose of the natural gas deoiling subunit is to remove the oil that may be mixed in the crude oil associated gas A and the crude oil associated gas B. As long as the purpose of the present invention can be achieved, the composition of the natural gas deoiling subunit is not particularly limited. In some embodiments, the natural gas deoiling unit includes a natural gas deoiler 8.

[0060] According to the present invention, the purpose of the natural gas station self-use subunit and the natural gas export subunit is to dehydrate the crude oil associated gas (including crude oil associated gas A and crude oil associated gas B) after entering their respective deoiling before self-use in the station or export. For example, when the station is self-used, the obtained natural gas can be used to supply natural gas to the demulsification and heating reaction unit for heating. The above-mentioned embodiment can better save the cost of using the system of the present invention for production operation.

[0061] According to the present invention, as long as the purpose of the present invention can be achieved, the composition of the natural gas station self-use subunit and the natural gas export subunit is not particularly limited. In some embodiments, the natural gas station self-use subunit includes a natural gas water separator 12.

[0062] According to the present invention, in some embodiments, along the material flow direction, the natural gas export sub-unit includes a natural gas cyclone separator 9 and a natural gas compressor skid 11 which are arranged in series with the natural gas deoiling sub-unit. In the aforementioned embodiment, the natural gas obtained by dehydration through the natural gas cyclone separator 9 can be pressurized and exported through the natural gas compressor skid 11.

[0063] According to the present invention, in order to ensure the safety of the system during operation, in some preferred embodiments, a natural gas compressor skid fault venting valve 10 is provided on the side line at the inlet of the natural gas compressor skid 11. In the aforementioned embodiment, when the natural gas compressor skid fault venting valve 10 is used for the natural gas compressor skid 11 fault venting, when the natural gas compressor skid 11 fails, the crude oil associated gas at the outlet of the natural gas cyclone separator 9 can be vented by this valve for emergency.

[0064] According to the present invention, in order to more conveniently control the withdrawal of crude oil associated gas A in the pre-water separation unit and the withdrawal of crude oil associated gas B in the three-phase separation unit, in some preferred embodiments, the crude oil associated gas processing unit also includes a crude oil associated gas pressure interlocking control subunit, which is used to control the withdrawal of crude oil associated gas A in the pre-water separation unit and the withdrawal of crude oil associated gas B in the three-phase separation unit.

[0065] According to the present invention, in some preferred embodiments, the crude oil associated gas pressure interlocking control subunit includes a pre-water separation separator outlet valve 3 arranged at the crude oil associated gas A outlet of the pre-water separation unit, and the pre-water separation separator outlet valve 3 is interlocked with the pressure of the pre-water separation separator outlet pipeline connecting the pre-water separation unit and the crude oil associated gas processing unit. When the air pressure in the pre-water separation separator outlet pipeline reaches the set pressure, the separated crude oil associated gas A enters the crude oil associated gas processing unit, and includes a three-phase separator outlet valve 7 arranged at the crude oil associated gas B outlet of the three-phase separation unit, and the three-phase separator outlet valve 7 is interlocked with the pressure of the three-phase separator outlet pipeline connecting the three-phase separation unit and the crude oil associated gas processing unit. When the pressure of the three-phase separator outlet pipeline reaches the set pressure, the separated crude oil associated gas B enters the crude oil associated gas processing unit.

[0066] According to the present invention, in order to ensure the safety of the system of the present invention when in use, in some embodiments, the system of the present invention also includes a safe venting unit, which includes a safety valve arranged at the outlet end of each unit in the system and an in-station venting pipeline 14 connected to each unit, and the outlet of each unit equipped with a safety valve is respectively connected to the in-station venting pipeline 14.

[0067] In the system of the present invention, the safety valves 2 that can be listed include the safety valve 2 arranged at the outlet end of the pre-water separator 1 in the pre-water separation unit, the safety valve 2 arranged at the outlet end of the three-phase separator 6 of the three-phase separation unit, the safety valve 2 arranged at the outlet end of the oil remover 8 in the crude oil associated gas processing unit, the safety valve 2 arranged at the outlet end of the natural gas cyclone separator 9 in the crude oil associated gas processing unit, the safety valve 2 arranged at the outlet end of the natural gas water separator 12; and the safety valve 2 arranged at the outlet end of the natural gas compressor skid 11.

[0068] According to the present invention, in some embodiments, the system of the present invention further comprises a purified oil collection unit connected to the purified crude oil of the three-phase separation unit.

[0069] According to the present invention, the function of the purified oil collection unit is to store the purified crude oil. As long as the purpose of the present invention can be achieved, the structure of the purified oil collection unit is not particularly limited. In some embodiments, the purified oil collection unit includes a purified oil tank 23.

[0070] According to the present invention, in some embodiments, the system described in the present invention also includes an in-station sewage pipe 18 connected to the pre-water separator 1 and the three-phase separator 6 respectively, which is used to discharge sewage when the pre-water separator is cleaned, and the sewage is discharged into the sewage tank in the station through the pre-water separator sewage pipe valve 24.

[0071] In the present invention, the system of the present invention may also be provided with pipelines for introducing various materials or leading out various materials as required. For example, an in-station dosing pipeline 15 for introducing a demulsifier into the system may be provided; an in-station self-use gas pipeline 13 may be provided to be connected to the outlet end of the natural gas water separator 12, so as to obtain the natural gas obtained by the natural gas water separator 12 for self-use.

[0072] A second aspect of the present invention provides a method for processing crude oil and crude oil associated gas gathering and transportation, the method is carried out in the system described in the present invention, the method comprising:

[0073] S1 Crude oil treatment: The incoming liquid is preliminarily separated into oil, water and gas in the pre-water separation unit to obtain crude oil saturated water mixed liquid, crude oil associated gas A and most of the free water. The separated crude oil saturated water mixed liquid enters the demulsification and heating reaction unit to mix and demulsify with the demulsifier to obtain a mixed demulsified liquid. The mixed demulsified liquid is heated in the demulsification and heating reaction unit and then enters the three-phase separation unit. The heated mixed demulsified liquid is then separated into oil, gas and water in the three-phase separation unit to obtain purified crude oil, crude oil associated gas B and sewage.

[0074] S2 Dehydration, heat exchange, blending and sewage treatment: The free water separated by the pre-water separation unit enters the sewage treatment pipeline 19 in the station, and the sewage separated by the three-phase separation unit enters the water blending pipeline 22 in the station. After that, part or all of the free water separated by the pre-water separation unit enters the water blending pipeline 22 in the station through the water inlet pipeline of the pre-water separation separator to mix with the sewage for heat exchange and temperature increase to obtain heated sewage. The heated sewage is transported to the wellhead of the oil well through the water blending pipeline 22 in the station to be blended with water to obtain the incoming liquid.

[0075] In the treatment method of the present invention, steps S1 and S2 only serve as labels to illustrate the treatment process in the treatment method of the present invention, and do not represent the treatment order. It can be understood that the incoming liquid is subjected to preliminary oil, water and gas separation in the pre-water separation unit, and most of the free water can be separated, and the crude oil saturated water mixture still contains a small amount of remaining free water.

[0076] In the present invention, a low-cost, simple and efficient dehydration heat exchange blending treatment and pre-dehydration treatment are combined, and compared with the sedimentation treatment in the existing joint station, the method flow of the present invention belongs to a short process flow, and free water has been separated in the pre-dehydration treatment, and less liquid enters the back-end treatment, which can further reduce the load. Under the condition of ensuring the normal operation of the oilfield gathering and processing system, it can reduce the daily energy consumption of the oilfield centralized processing station, meet the safety and environmental protection requirements, and improve the economic benefits of the later stage of oilfield development.

[0077] According to the present invention, in some embodiments, in step S1, the incoming liquid comes from an oil-water mixture mixed with water at the wellhead of the oil well.

[0078] In the present invention, it is understood that the crude oil in the wellhead of the oil well contains a portion of associated gas, and the associated gas is continuously precipitated in the early stage of the treatment in the method of the present invention.

[0079] According to the present invention, in some preferred embodiments, the water content of the incoming liquid is greater than 90wt%, preferably 91wt%-99wt%. The above embodiments can better collect and transport crude oil, and the treatment method of the present invention can not only obtain purified crude oil with a water content of less than 0.5%, but also reduce the daily energy consumption of the oilfield centralized processing station.

[0080] According to the present invention, as long as the purpose of the present invention can be achieved, the flow rate of the liquid entering the station can be selected as needed, for example, it can be 20-30m 3 / h, for example 26.46m 3 / h、20m 3 / h.

[0081] According to the present invention, in some embodiments, in step S1, the pre-water separator inlet heating furnace valve 17 in the crude oil level interlocking subsystem is automatically interlocked with the liquid level of the pre-water separator unit. When the pre-water separator 1 reaches the set liquid level (for example, 1200 mm), the separated crude oil saturated water mixture passes through the pre-water separator inlet heating furnace valve 17 and enters the emulsification and heating reaction unit. The demulsifier is mixed with the separated crude oil saturated water mixture through the station dosing pipeline 15 for demulsification reaction to obtain a mixed demulsified liquid. After the mixed demulsified liquid is heated in the demulsification and heating reaction unit, it enters the three-phase separation unit for oil, gas and water three-phase separation. The three-phase separator oil outlet valve 20 is automatically interlocked with the liquid level of the three-phase separation unit. When the liquid volume in the oil chamber of the three-phase separation unit reaches the set liquid level, the separated purified crude oil enters the purified oil tank 23 modified in the purified oil collection unit for storage.

[0082] According to the present invention, the demulsifier in step S1 can be selected as needed, and the present invention has no special limitation on this.

[0083] According to the present invention, as long as the purpose of the present invention can be achieved, the flow rate of the demulsifier can be selected as needed, for example, it can be 50-70 L / h, for example 60 L / h.

[0084] According to the present invention, as long as the purpose of the present invention can be achieved, the flow rate of the crude oil saturated water mixture can be selected as needed, for example, it can be 10-20m 3 / h, for example 17.5m 3 / h、18.13m 3 / h.

[0085] According to the present invention, as long as the purpose of the present invention can be achieved, the heating temperature is not particularly limited. In some embodiments, the heating temperature is 60-70°C.

[0086] According to the present invention, as long as the purpose of the present invention can be achieved, the water flow rate in the pre-water separator 1 is not particularly limited, for example, 1-20m 3 / h, for example 2.5m 3 / h、8.3m 3 / h.

[0087] According to the present invention, as long as the purpose of the present invention can be achieved, the flow rate of purified crude oil is not particularly limited, for example, 0.5-3m 3 / h, for example 0.8m 3 / h、1.5m 3 / h.

[0088] According to the present invention, in some embodiments, in step S2, the pre-water separator outlet valve 16 in the free water flow interlocking control subsystem is interlocked with the outlet flow of the pre-water separator unit, and the valve opening is automatically controlled by setting the outlet flow, and the separated free water enters the sewage treatment pipeline 19 in the station, and the sewage separated by the three-phase separation unit 6 enters the station water mixing pipeline 22 through the three-phase separation unit water mixing valve 5, and the pre-water separator outlet water mixing pipeline valve 21 on the pre-water separator outlet water mixing pipeline controls all or part of the free water to enter the station water mixing pipeline 22 to mix with the sewage for heat exchange and temperature increase, wherein the flow detection instrument set on the pre-water separator outlet water mixing pipeline is used to measure the amount of free water separated by the pre-water separator unit entering the station water mixing pipeline 22, so as to adjust the opening of the pre-water separator outlet water mixing pipeline valve 21. The heated sewage enters the station water mixing pipeline 22 together and is pressurized by the water mixing pump and transported to the wellhead of the oil well for water mixing.

[0089] According to the present invention, there is no special limitation on the setting of water flow rate, and those skilled in the art can set it according to actual needs, that is, the outlet valve 16 of the pre-water separator is interlocked with the flow detection instrument of the upstream pipeline, and the opening of the outlet valve of the pre-water separator is automatically adjusted according to the flow rate to ensure stable flow rate.

[0090] According to the present invention, as long as the purpose of the present invention can be achieved, the conditions of the pre-water separation unit and the three-phase separation unit are not particularly limited. In some preferred embodiments, the working pressure of the pre-water separation unit is greater than the working pressure of the three-phase separation unit. The above-mentioned embodiment can make the free water separated by the pre-water separation unit enter the water mixing pipeline 22 in the station more smoothly and mix with the sewage from the three-phase separation unit for heat exchange and temperature increase. The heated sewage enters the water mixing pipeline 22 in the station together and is pressurized by the water mixing pump and transported to the wellhead of the oil well for water mixing.

[0091] According to the present invention, as long as the purpose of the present invention can be achieved, there is no special restriction on the working pressure of the pre-water separation unit and the working pressure of the three-phase separation unit, and they can be selected according to actual needs. For example, the working pressure of the pre-water separation unit is 0.3MPa, and the working pressure of the three-phase separation unit is 0.25MPa.

[0092] According to the present invention, in some preferred embodiments, the method of the present invention further includes: Step S3 of crude oil associated gas processing: when the air pressure in the outlet pipeline of the pre-water separator reaches the set pressure, the separated crude oil associated gas A enters the natural gas deoiler 8 in the crude oil associated gas processing unit, when the pressure in the outlet pipeline of the three-phase separator reaches the set pressure, the outlet valve 7 of the three-phase separator automatically opens, and the separated crude oil associated gas B enters the natural gas deoiler 8 in the crude oil associated gas processing unit, and the crude oil associated gas A and the crude oil associated gas B are deoiled in the natural gas deoiler 8 to obtain purified crude oil associated gas, and the purified crude oil associated gas is divided into two parts, one part enters the natural gas water separator 12 for crude oil associated gas dehydration, and the dehydrated crude oil associated gas enters the downstream in-station self-use gas pipeline 13 for self-use of gas-consuming equipment in the station, and the other part of the purified crude oil associated gas enters the natural gas cyclone separator 9 for pre-natural gas dehydration, and the dehydrated natural gas enters the natural gas compressor skid 11 for pressurized external transmission.

[0093] According to the present invention, as long as the purpose of the present invention can be achieved, the flow rate of the purified crude oil associated gas entering the natural gas water separator 12 is not particularly limited, for example, 8000-12000m 3 / d, for example, 10000m 3 / d.

[0094] According to the present invention, as long as the purpose of the present invention can be achieved, the flow rate of the crude oil associated gas after purification entering the natural gas cyclone separator 9 is not particularly limited, for example, 7000-8000m 3 / d.

[0095] According to the present invention, as long as the purpose of the present invention can be achieved, there is no special restriction on the set pressures of the air outlet pipe of the pre-water separator and the air outlet pipe of the three-phase separator, and they can be selected according to actual processing requirements. For example, the set pressure of the air outlet pipe of the pre-water separator is 0.3MPa, and the set pressure of the air outlet pipe of the three-phase separator is 0.25MPa.

[0096] According to the present invention, in the processing method of gathering and transporting crude oil and crude oil associated gas, if a fault occurs, the safe venting unit of the present invention can be used for venting. For example, when the gas phase pressure in the pre-water separator 1 in the pre-water separation unit reaches the safety pressure setting value, the crude oil associated gas separated by the pre-water separator enters the station venting pipeline 14 through the safety valve 2 at its outlet end. The working process of the safety valve of the three-phase separator 6, the natural gas oil remover 8, the natural gas cyclone separator 9, the natural gas compressor skid 11, and the natural gas water separator 12 is the same as that of the pre-water separator safety valve 2. In addition, the natural gas compressor skid fault venting valve 10 is used for the natural gas compressor skid 11 fault venting. When the natural gas compressor skid 11 fails, the crude oil associated gas at the outlet of the natural gas cyclone separator 9 can be vented by this valve for emergency.

[0097] The present invention will be described in detail below by way of examples. The examples are carried out in the above-mentioned crude oil and crude oil associated gas gathering and transportation processing system, such as Figure 1 As shown: the pre-water separation unit includes a pre-water separation separator 1 (a three-phase separation device), the three-phase separation unit includes a three-phase separator 6, and the demulsification and heating reaction unit includes a coil heating furnace 4.

[0098] The processing methods for gathering and transporting crude oil and associated gas include:

[0099] S1 Crude oil processing: the incoming liquid is preliminarily separated into oil, water and gas in the pre-water separator 1, and the crude oil saturated water mixture, crude oil associated gas A and most of the free water are separated. The pre-water separator inlet heating furnace valve 17 is automatically interlocked with the liquid level of the pre-water separator 1. When the pre-water separator 1 reaches the set liquid level, the separated crude oil saturated water mixture passes through the pre-water separator inlet heating furnace valve 17 and enters the coil-type heating furnace 4. The demulsifier in the coil passes through the station dosing pipeline 15 and is mixed with the separated crude oil saturated water mixture for demulsification reaction to obtain a mixed demulsified liquid. After being heated in the demulsification and heating reaction unit, the mixed demulsified liquid enters the three-phase separator 6 for oil, gas and water three-phase separation. The three-phase separator oil outlet valve 20 is automatically interlocked with the liquid level of the three-phase separator 6. When the liquid volume in the oil chamber of the three-phase separator 6 reaches the set liquid level, the separated purified crude oil enters the purified oil tank 23 for storage;

[0100] S2 Dehydration, heat exchange, blending and sewage treatment: The pre-water separator outlet valve 16 in the free water flow interlocking control subsystem is interlocked with the pre-water separator outlet flow. The valve opening is automatically controlled by setting the outlet flow. The separated free water enters the station sewage treatment pipeline 19, and the sewage separated by the three-phase separator 6 enters the station water blending pipeline 22 through the three-phase separator water blending valve 5. Among them, because the set working pressure of the pre-water separator 1 is higher than the set working pressure of the three-phase separator 6, the free water separated by the pre-water separator 1 can pass through the pre-water separator outlet water into the water blending pipeline valve The gate 21 enters the water mixing pipe 22 in the station and mixes with the sewage separated by the three-phase separator 6 for heat exchange and temperature increase. The flow detection instrument set on the water inlet and water mixing pipe of the pre-water separation separator is used to measure the amount of free water separated by the pre-water separation unit entering the water mixing pipe 22 in the station, so as to adjust the opening of the valve 21 of the water inlet and water mixing pipe of the pre-water separation separator; the heated sewage enters the water mixing pipe 22 in the station together and is pressurized by the water mixing pump and transported to the wellhead of the oil well for water mixing to obtain the incoming liquid, which continues to enter the system for the collection and transportation of crude oil and crude oil associated gas;

[0101] S3 Crude oil associated gas processing: When the air pressure in the outlet pipeline of the pre-water separator reaches the set pressure, the separated crude oil associated gas A enters the natural gas deoiler 8 in the crude oil associated gas processing unit. When the pressure in the outlet pipeline of the three-phase separator reaches the set pressure, the outlet valve 7 of the three-phase separator automatically opens, and the separated crude oil associated gas B enters the crude oil associated gas processing unit and enters the natural gas deoiler 8 in the crude oil associated gas processing unit. The crude oil associated gas A and the crude oil associated gas B are deoiled in the natural gas deoiler 8 to obtain purified crude oil associated gas. The purified crude oil associated gas is divided into two parts, one part enters the natural gas water separator 12 for crude oil associated gas dehydration, and the dehydrated crude oil associated gas enters the downstream in-station self-use gas pipeline 13 for self-use of gas-consuming equipment in the station; the other part of the purified crude oil associated gas enters the natural gas cyclone separator 9 for pre-natural gas dehydration, and the dehydrated natural gas enters the natural gas compressor skid 11 for pressurized external transmission.

[0102] In the following comparative example 1: Figure 2 As shown, Figure 2The schematic diagram of the existing crude oil and crude oil associated gas collection and transportation processing system is taken as an example of the existing crude oil collection and transportation processing method of another crude oil centralized processing station in Northeast China (Qinjiatun Joint Station in Northeast China). Liquid from each oil field block enters the station through the crude oil collection and transportation pipeline, and the liquid entering the station enters the buffer tank for liquid buffering and establishes a stable liquid level, and then enters the three-phase separator for oil, gas and water three-phase separation; the three-phase separator is a heating three-phase separator, and the liquid entering the station is heated to the operating temperature required by the three-phase separator after entering the three-phase separator, and is mixed with the demulsifier in the dosing pipeline for demulsification reaction in the three-phase separator to separate the purified crude oil, crude oil associated gas and free water; the purified crude oil enters the purification oil tank in the station for storage, and is loaded and transported out through the loading pump;

[0103] The separated crude oil associated gas enters the downstream natural gas separator for further natural gas purification treatment, and then enters the station's own gas pipeline after treatment, and is used for heating gas consumption by equipment such as heating furnaces in the station;

[0104] The separated free water enters the water blending sedimentation tank in the station. Part of the free water is pressurized and transported out through the water blending pump, and then heated up by the water blending heating furnace in the station and then transported to the wellheads of various oil wells for water blending and oil collection. The other part of the free water enters the sewage treatment system in the station for further purification and filtration.

[0105] When the water content of the purified oil of the three-phase separator exceeds the standard, a part of the crude oil emulsion separated by the three-phase separator enters the water-added settling tank. The water-added settling tank can pressurize this part of the crude oil emulsion through the dehydration pump and then pump it into the inlet pipeline of the three-phase separator for circulating dehydration treatment.

[0106] In the following comparative example 2: Figure 3 As shown, Figure 3 The treatment process is basically the same as that in the present invention, the only difference is that the free water separated by the pre-water separator does not enter the water mixing pipeline in the station, and the separated free water all enters the downstream sewage treatment system. The other treatment processes are consistent with the other treatment processes in the present invention. The specific process is:

[0107] S1 The oil wellhead pipes and oil-drawn liquid enter the oilfield centralized processing station. The incoming liquid enters the pre-water separator for preliminary oil, water and gas separation into crude oil saturated water mixture, crude oil associated gas A and most of the free water; the pre-water separator enters the heating furnace valve and the pre-water separator liquid level is automatically interlocked. When the pre-water separator reaches the set liquid level, the separated crude oil saturated water mixture passes through the pre-water separator and enters the coil heating furnace valve. The demulsifier passes through the station dosing pipeline and is mixed with the separated crude oil saturated water mixture for demulsification reaction to obtain a mixed demulsified liquid; the mixed demulsified liquid is heated to a certain temperature in the demulsification and heating reaction unit to obtain a heated mixed demulsified liquid. The heated mixed demulsified liquid enters the three-phase separator for oil, gas and water three-phase separation. The phase separator oil outlet valve is automatically interlocked with the liquid level of the three-phase separator. When the liquid volume in the oil chamber of the three-phase separator reaches the set liquid level, the separated purified crude oil enters the purified oil tank for storage;

[0108] The valve of the pre-water separator sewage pipeline in the S2 free water flow interlocking control subsystem is interlocked with the pre-water separator outlet flow. The valve opening is automatically controlled by setting the outlet flow. Most of the separated free water enters the sewage pipeline and then all enters the sewage treatment process in the downstream process for further filtration and treatment.

[0109] S3 When the gas pressure in the outlet pipeline of the pre-water separator reaches the set pressure, the separated crude oil associated gas A enters the natural gas deoiler in the crude oil associated gas processing unit. When the pressure in the outlet pipeline of the three-phase separator reaches the set pressure, the outlet valve of the three-phase separator automatically opens, and the separated crude oil associated gas B enters the crude oil associated gas processing unit and enters the natural gas deoiler in the crude oil associated gas processing unit. The crude oil associated gas A and the crude oil associated gas B are deoiled in the natural gas deoiler to obtain purified crude oil associated gas. The purified crude oil associated gas is divided into two parts. One part enters the natural gas water separator for crude oil associated gas dehydration. The dehydrated crude oil associated gas enters the downstream in-station self-use gas pipeline for self-use of gas-consuming equipment in the station; the other part of the purified crude oil associated gas enters the natural gas cyclone separator for pre-natural gas dehydration. The dehydrated natural gas enters the natural gas compressor skid for pressurization and external When the air pressure in the outlet pipeline of the pre-water separator reaches the set pressure, the separated crude oil associated gas A enters the natural gas deoiler in the crude oil associated gas processing unit. When the pressure in the outlet pipeline of the three-phase separator reaches the set pressure, the outlet valve of the three-phase separator automatically opens, and the separated crude oil associated gas B enters the crude oil associated gas processing unit. The crude oil associated gas A and the crude oil associated gas B are deoiled in the natural gas deoiler to obtain purified crude oil associated gas. The purified crude oil associated gas is divided into two parts, one part enters the natural gas water separator for crude oil associated gas dehydration, and the dehydrated crude oil associated gas enters the downstream in-station self-use gas pipeline for self-use of gas-consuming equipment in the station; the other part of the purified crude oil associated gas enters the natural gas cyclone separator for pre-natural gas dehydration, and the dehydrated natural gas enters the natural gas compressor skid for pressurized external transmission.

[0110] Example 1

[0111] The crude oil and crude oil associated gas gathering and transportation processing system of the present invention is applied in the crude oil gathering and transportation processing method of the Sujiatun Oilfield centralized processing station in Northeast China:

[0112] In step S1, the incoming liquid (35°C) comes from the oil-water mixture after being mixed with water (40°C) at the wellhead of the oil well; the water content in the incoming liquid is 94.5wt%; the flow rate of the incoming liquid is 26.46m 3 / h; the oil-water chamber of the pre-water separator 1 is set at a liquid level of 1200mm; the flow rate of the crude oil saturated water mixture is 18.13m 3 / h; the flow rate of demulsifier is 60L / h; the heating temperature is 60℃, and the temperature of the crude oil saturated water mixture after heating is 54℃; the set liquid level of the water volume in the three-phase separator 6 is 1600mm; the flow rate of purified crude oil is 1.5m 3 / h; the water content of the purified crude oil is less than 0.5wt%;

[0113] The water flow rate in the pre-water separator 1 is 8.3m 3 / h; the working pressure of the pre-water separator 1 is set to 0.3MPa; the working pressure of the three-phase separator 6 is set to 0.25MPa;

[0114] The set pressure in the outlet pipe of the pre-water separator is 0.3MPa; the set pressure in the outlet pipe of the three-phase separator is 0.25MPa; the flow rate of the purified crude oil associated gas entering the natural gas water separator 12 is 10000m 3 / d; the flow rate of crude oil associated gas after purification entering natural gas cyclone separator 9 is 7000m 3 / d.

[0115] From January 6, 2022 to January 15, 2022, a total of 6550m 3 Entered the station to get fluid, consumed 14750m 3 natural gas.

[0116] Compared with the comparative example 1, the amount of natural gas consumed per thousand cubic meters of liquid treated is about 2251m 3 Compared with the comparative example 1, the amount of natural gas consumed per thousand cubic meters of liquid treated is reduced by about 351m 3 .

[0117] Compared with the comparative example 2, the amount of natural gas consumed per thousand cubic meters of liquid treated is about 2251m 3 Compared with the comparative example 2, the amount of natural gas consumed per thousand cubic meters of liquid treated is reduced by about 40m 3 .

[0118] Example 2

[0119] The crude oil and crude oil associated gas gathering and transportation processing system of the present invention is applied in the crude oil gathering and transportation processing method of the Sujiatun Oilfield centralized processing station in Northeast China:

[0120] In step S1, the incoming liquid is an oil-water mixture mixed with water (40°C) at the wellhead of the oil well; the water content of the incoming liquid is 96wt%; the flow rate of the incoming liquid is 20m 3 / h; the oil-water chamber of the pre-water separator 1 is set at a liquid level of 1200mm; the flow rate of the crude oil saturated water mixture is 17.5m 3 / h; the flow rate of demulsifier is 60L / h; the heating temperature is 60℃; the set liquid level of the water chamber 6 of the three-phase separator is 1800mm; the flow rate of purified crude oil is 0.8m 3 / h; the water content of the purified crude oil is less than 0.5wt%;

[0121] The water flow rate in the pre-water separator 1 is 2.5m 3 / h; the working pressure of the pre-water separator 1 is set to 0.3MPa; the working pressure of the three-phase separator 6 is set to 0.25MPa;

[0122] The set pressure in the outlet pipe of the pre-water separator is 0.3MPa; the set pressure in the outlet pipe of the three-phase separator is 0.25MPa; the flow rate of the purified crude oil associated gas entering the natural gas water separator 12 is 10000m 3 / d; the flow rate of crude oil associated gas after purification entering natural gas cyclone separator 9 is 8000m 3 / d.

[0123] From April 6, 2022 to April 15, 2022, a total of 7890m 3 Entered the station to get liquid, consuming 17833m 3 natural gas.

[0124] Compared with the comparative example 1, the amount of natural gas consumed per thousand cubic meters of liquid treated is about 2260m 3 Compared with the comparative example 1, the amount of natural gas consumed per thousand cubic meters of liquid treated is reduced by 341m 3 .

[0125] Compared with the comparative example 2, the amount of natural gas consumed per thousand cubic meters of liquid treated is about 2260m 3 Compared with the comparative example 1, the amount of natural gas consumed per thousand cubic meters of liquid treated is reduced by 31m 3 .

[0126] Comparative Example 1

[0127] The existing sedimentation crude oil gathering and transportation processing method is applied in the crude oil gathering and transportation processing method of Qinjiatun Joint Station in Northeast China:

[0128] The temperature of the incoming liquid is 35℃, the water content is 94%, and the flow rate of the incoming liquid is 120m 3 / h; the set liquid level of the water chamber of three-phase separators 1 and 2 is 1600mm; the operating temperature of the two three-phase separators is 65℃; the flow rate of demulsifier is 120L / h; the flow rate of purified crude oil is 7.2m 3 / h; the water content of the purified crude oil is less than 0.5wt%;

[0129] Among them, the water flow rate in the three-phase separator connected to a buffer tank is 105m 3 / h; the water outflow rate in the three-phase separator connected to another buffer tank is 15m 3 / h; the working pressure of the two three-phase separators is set to 0.25MPa; the outlet flow rate of the water injection pipeline of the water injection buffer tank is 70m 3 / h.

[0130] The set pressure in the outlet pipes of the two three-phase separators is 0.25MPa; the flow rate of the purified crude oil associated gas entering the natural gas separator is 150m 3 / d; the operating temperature of the two water-mixed heating furnaces is 65℃.

[0131] From February 15, 2022 to February 16, 2022, a total of 5760m 3 Entered the station to collect liquid, consuming 14987m 3 Natural gas (including gas consumption of 2 water-blended heating furnaces and 1 three-phase separator).

[0132] Comparative Example 2

[0133] A crude oil and crude oil associated gas gathering and transportation processing system similar to the present invention is used in the crude oil gathering and transportation processing method of the Sujiatun Oilfield centralized processing station in Northeast China:

[0134] In step S1, the incoming liquid (35°C) comes from the oil-water mixture after being mixed with water (40°C) at the wellhead of the oil well; the water content in the incoming liquid is 91wt%; the flow rate of the incoming liquid is 26.46m 3 / h; the oil-water chamber of the pre-water separator 1 is set at a liquid level of 1100mm; the flow rate of the crude oil saturated water mixture is 22.3m 3 / h; the flow rate of demulsifier is 75L / h; the heating temperature is 55℃, and the temperature of the crude oil saturated water mixture after heating is 50℃; the flow rate of purified crude oil is 1.6m 3 / h; the water content of the purified crude oil is less than 0.5wt%;

[0135] The water flow rate in the pre-water separator 1 is 4.3m 3 / h; the working pressure of the pre-water separator 1 is set to 0.3MPa; the working pressure of the three-phase separator 6 is set to 0.25MPa;

[0136] The set pressure in the outlet pipe of the pre-water separator is 0.3MPa; the set pressure in the outlet pipe of the three-phase separator is 0.25MPa; the flow rate of the purified crude oil associated gas entering the natural gas water separator 12 is 10000m 3 / d; the flow rate of crude oil associated gas after purification entering natural gas cyclone separator 9 is 7000m 3 / d.

[0137] From March 1, 2022 to March 10, 2022, a total of 6610m 3 Entered the station to get fluid, consumed 15150m 3 natural gas.

[0138] Through the above embodiments and comparative examples, it can be seen that the system of the present invention saves daily operating costs and effectively solves the problem of high energy consumption of oil field centralized processing stations in the later stage of oil field development; at the same time, the crude oil processing method in the station is simple, and the design of the crude oil settling tank in the traditional joint station is cancelled, which greatly reduces the construction investment; the natural gas processing process is complete, and while ensuring that the gas quality meets the standards, a recovery and external transmission process of crude oil associated gas is established, which ensures the effective utilization of crude oil associated gas under different needs.

[0139] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A crude oil and crude oil associated gas gathering and transportation processing system, characterized in that: The system includes: The pre-water separation unit is used for the preliminary separation of oil, water and gas from the incoming liquid, and separates the crude oil saturated water mixture, crude oil associated gas A and most of the free water; A demulsification and heating reaction unit, used for mixing and demulsifying a crude oil saturated water mixture with a demulsifier to obtain a mixed demulsified liquid, and heating the mixed demulsified liquid to obtain a heated mixed demulsified liquid; A three-phase separation unit is used to separate the oil, gas and water three-phases of the heated mixed demulsified liquid to obtain purified crude oil, crude oil associated gas B and sewage; The dehydration heat exchange blending unit includes an in-station water blending pipeline connected to the sewage outlet of the three-phase separation unit, and an in-station sewage treatment pipeline connected to the free water outlet of the pre-water separation unit; Among them, the sewage treatment pipeline in the station is connected with the water injection pipeline in the station through the water inlet and outlet pipe of the pre-water separation separator, which is used to allow part or all of the free water separated by the pre-water separation unit to enter the water injection pipeline in the station through the water inlet and outlet pipe of the pre-water separation separator to mix with the sewage separated by the three-phase separation unit for heat exchange and heating to obtain heated sewage. The heated sewage is transported to the wellhead of the oil well through the water injection pipeline in the station to be injected with water to obtain the incoming liquid.

2. The processing system according to claim 1, wherein: The water outlet and water inlet pipe of the pre-water separation separator is provided with a valve of the water outlet and water inlet pipe of the pre-water separation separator; and / or The pre-water separation unit comprises a pre-water separation separator, and the pre-water separation separator is preferably a three-phase separation device; and / or The demulsification and heating reaction unit comprises a heating furnace, and preferably the heating furnace is a coil heating furnace; and / or The three-phase separation unit includes a three-phase separator.

3. The processing system according to claim 1 or 2, wherein: The sewage outlet of the three-phase separation unit is provided with a three-phase separator water injection valve; and / or The system also includes a free water flow interlocking control subsystem for interlocking control of the outflow flow of free water in the pre-water separation unit. Preferably, the free water flow interlocking control subsystem includes a pre-water separation separator outlet valve arranged at the free water outlet of the pre-water separation unit, and the pre-water separation separator outlet valve is interlocked with the outlet flow of the pre-water separation unit, and the valve opening is automatically controlled by setting the outlet flow.

4. A processing system according to any one of claims 1 to 3, wherein: The system also includes a crude oil level interlocking subsystem, which is used for the crude oil saturated water mixture to enter the demulsification and heating reaction unit when it reaches the set liquid level, and for the purified crude oil to be led out of the three-phase separation unit when it reaches the set liquid level; Preferably, the crude oil level interlocking subsystem includes a pre-water separation separator inlet valve for a heating furnace provided at the outlet of the crude oil saturated water mixture of the pre-water separation unit, and the pre-water separation separator inlet valve for a heating furnace is automatically interlocked with the liquid level of the pre-water separation unit. When the pre-water separation unit reaches the set liquid level, the separated crude oil saturated water mixture passes through the pre-water separation unit and enters the demulsification and heating reaction unit, and includes a three-phase separator oil outlet valve provided at the outlet of the purified crude oil of the three-phase separation unit, and the three-phase separator oil outlet valve is automatically interlocked with the liquid level of the three-phase separation unit. When the liquid volume in the oil chamber of the three-phase separation unit reaches the set liquid level, the separated purified crude oil is led out of the three-phase separation unit.

5. The processing system according to any one of claims 1 to 4, wherein: The system also includes a crude oil associated gas processing unit, which is used to remove oil and water from the crude oil associated gas A and the crude oil associated gas B to obtain natural gas; Preferably, along the material flow direction, the crude oil associated gas processing unit includes a natural gas deoiling sub-unit respectively connected to the crude oil associated gas A outlet of the pre-water separation unit and the crude oil associated gas B outlet of the three-phase separation unit, as well as a natural gas station self-use sub-unit and a natural gas export sub-unit each independently connected to the outlet of the natural gas deoiling sub-unit.

6. The system according to claim 5, wherein: The natural gas deoiling unit comprises a natural gas deoiler; and / or The self-use subunit in the natural gas station includes a natural gas water distributor; and / or Along the material flow direction, the natural gas export sub-unit includes a natural gas cyclone separator and a natural gas compressor skid which are arranged in series with the natural gas deoiling sub-unit; Preferably, a natural gas compressor skid fault venting valve is provided on the side line at the inlet of the natural gas compressor skid.

7. The system according to claim 5 or 6, wherein: The crude oil associated gas processing unit also includes a crude oil associated gas pressure interlocking control subunit, which is used to control the extraction of the crude oil associated gas A from the pre-water separation unit and the extraction of the crude oil associated gas B from the three-phase separation unit; Preferably, the crude oil associated gas pressure interlocking control subunit includes a pre-water separation separator outlet valve arranged at the crude oil associated gas A outlet of the pre-water separation unit, and the pre-water separation separator outlet valve is interlocked with the pressure of the pre-water separation separator outlet pipeline connecting the pre-water separation unit and the crude oil associated gas processing unit. When the air pressure in the pre-water separation separator outlet pipeline reaches the set pressure, the separated crude oil associated gas A enters the crude oil associated gas processing unit, and includes a three-phase separator outlet valve arranged at the crude oil associated gas B outlet of the three-phase separation unit, and the three-phase separator outlet valve is interlocked with the pressure of the three-phase separator outlet pipeline connecting the three-phase separation unit and the crude oil associated gas processing unit. When the pressure of the three-phase separator outlet pipeline reaches the set pressure, the separated crude oil associated gas B enters the crude oil associated gas processing unit.

8. The system according to any one of claims 1 to 7, wherein: The system further comprises a safety venting unit, which comprises a safety valve provided at the outlet of each unit in the system and an in-station venting pipeline connected to each unit, and the outlet of each unit equipped with a safety valve is respectively connected to the in-station venting pipeline; and / or The system further comprises a purified oil collection unit connected to the purified crude oil of the three-phase separation unit, and preferably the purified oil collection unit comprises a purified oil tank.

9. A method for gathering and transporting crude oil and associated gas, the method being carried out in the system according to any one of claims 1 to 8, the method comprising: S1 Crude oil treatment: The incoming liquid is preliminarily separated into oil, water and gas in the pre-water separation unit to obtain crude oil saturated water mixed liquid, crude oil associated gas A and most of the free water. The separated crude oil saturated water mixed liquid enters the demulsification and heating reaction unit to mix and demulsify with the demulsifier to obtain a mixed demulsified liquid. The mixed demulsified liquid is heated in the demulsification and heating reaction unit and then enters the three-phase separation unit. The heated mixed demulsified liquid is then separated into oil, gas and water in the three-phase separation unit to obtain purified crude oil, crude oil associated gas B and sewage. S2 Dehydration, heat exchange, blending and sewage treatment: Most of the free water separated by the pre-water separation unit enters the sewage treatment pipeline in the station, and the sewage separated by the three-phase separation unit enters the water blending pipeline in the station. After that, part or all of the free water separated by the pre-water separation unit enters the water blending pipeline in the station through the water inlet pipeline of the pre-water separator to mix with the sewage for heat exchange and temperature rise to obtain heated sewage. The heated sewage is transported to the wellhead of the oil well through the water blending pipeline in the station to be blended with water to obtain the incoming liquid.

10. The method according to claim 9, wherein: In step S1, the incoming liquid is an oil-water mixture mixed with water at the wellhead of the oil well, and the water content in the incoming liquid is preferably greater than 90wt%, preferably 91wt%-99wt%; and / or In step S1, the pre-water separator in the crude oil level interlocking subsystem is automatically interlocked with the liquid level of the pre-water separator unit. When the pre-water separator reaches the set liquid level, the separated crude oil saturated water mixture passes through the pre-water separator in the heating furnace valve and enters the emulsification and heating reaction unit. The demulsifier is mixed with the separated crude oil saturated water mixture through the station dosing pipeline for demulsification reaction to obtain a mixed demulsified liquid. After the mixed demulsified liquid is heated in the demulsification and heating reaction unit, it enters the three-phase separation unit for oil, gas and water three-phase separation. The oil outlet valve of the three-phase separator is automatically interlocked with the liquid level of the three-phase separation unit. When the liquid volume in the oil chamber of the three-phase separation unit reaches the set liquid level, the separated purified crude oil enters the purified oil tank modified in the purified oil collection unit for storage; and / or In step S1, the heating temperature is 60-70°C.

11. The method according to claim 9 or 10, wherein: In step S2, the outlet valve of the pre-water separator in the free water flow interlocking control subsystem is interlocked with the outlet flow of the pre-water separation unit, and the valve opening is automatically controlled by setting the outlet flow, and the separated free water enters the sewage treatment pipeline in the station, and the sewage separated by the three-phase separation unit enters the water mixing pipeline in the station through the three-phase separation unit water mixing valve, and the pre-water separator outlet water inlet water mixing pipeline valve on the pre-water separator outlet water inlet water mixing pipeline controls all or part of the free water to enter the water mixing pipeline in the station to mix with the sewage for heat exchange and temperature increase, and the heated sewage enters the water mixing pipeline in the station together and is pressurized and transported to the wellhead of the oil well through the water mixing pump for water mixing; Preferably, the working pressure of the pre-water separation unit is greater than the working pressure of the three-phase separation unit.

12. The method according to any one of claims 9 to 11, wherein: The method also includes: step S3 of crude oil associated gas processing: when the air pressure in the outlet pipeline of the pre-water separator reaches the set pressure, the separated crude oil associated gas A enters the natural gas deoiler in the crude oil associated gas processing unit, when the pressure in the outlet pipeline of the three-phase separator reaches the set pressure, the outlet valve of the three-phase separator automatically opens, and the separated crude oil associated gas B enters the crude oil associated gas processing unit and the natural gas deoiler in the crude oil associated gas processing unit, the crude oil associated gas A and the crude oil associated gas B are deoiled in the natural gas deoiler to obtain purified crude oil associated gas, the purified crude oil associated gas is divided into two parts, one part enters the natural gas water separator for crude oil associated gas dehydration, the dehydrated crude oil associated gas enters the downstream in-station self-use gas pipeline for self-use of gas-consuming equipment in the station, and the other part of the purified crude oil associated gas enters the natural gas cyclone separator for pre-natural gas dehydration, and the dehydrated natural gas enters the natural gas compressor skid for pressurized external transmission.

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