Ground oil and gas gathering and transportation optimization system for gas drive development extraction section of low-permeability oil field

Abstract

The utility model discloses a low permeability oil field gas drive exploitation section ground oil gas gathering and transportation optimization system which comprises a well mouth, an oil-water separation tank and a gas purification tank, the tail end of the oil-water separation tank is sequentially connected with a well site oil storage tank and a combination station, and the tail end of the gas purification tank is connected with a first separation tank and a second separation tank. The top of the oil-water separation tank is respectively connected with the front and rear ends of the gas purification tank through a group of shunt pipes, and a purification assembly is arranged in the gas purification tank. According to the utility model, the extraction section of carbon dioxide injection oil extraction is specifically optimized, different working modes are adjusted according to different contents of carbon dioxide in the extracted gas monitored by the carbon dioxide monitor, the working efficiency is improved, the flow direction of the extracted gas is scientifically and reasonably distributed, the waste of resources is avoided, and the production cost is reduced. The recovery of carbon dioxide and the purification of impurities in produced gas are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of oil and gas gathering and transportation, in particular to an optimized system for surface oil and gas gathering and transportation in the production section of gas flooding development in low-permeability oilfields. Background Technique

[0002] Oil and gas gathering and transportation refers to the whole process of gathering the oil, associated natural gas and other products produced by scattered oil wells, and through necessary treatment and primary processing, the qualified oil and natural gas are respectively transported to refineries and natural gas users. It mainly includes processes such as oil and gas separation, oil and gas metering, crude oil dehydration, natural gas purification, crude oil stabilization, and light hydrocarbon recovery.

[0003] At present, water injection and gas injection development in low-permeability oilfields is becoming more and more common. Among them, the carbon dioxide flooding technology is used more frequently. The carbon dioxide flooding technology is a technology that injects carbon dioxide into the oil reservoir to improve the oil recovery rate of the oilfield. When carbon dioxide first contacts the formation crude oil, it cannot form a miscible phase. However, under the conditions of appropriate pressure, temperature and crude oil composition, carbon dioxide can form a miscible front. The supercritical fluid will extract heavier hydrocarbons from the crude oil and continuously concentrate the gas at the displacement front. Thus, carbon dioxide and crude oil become a miscible liquid, forming a single liquid phase, so that the formation crude oil can be effectively displaced to the production well.

[0004] However, at present, the traditional oil-gas-water separation system is still widely used for the surface oil and gas gathering and transportation system in the production section of gas injection production, and there is not much targeted optimization. Especially in the well fields of carbon dioxide flooding, a series of optimization measures are needed to improve the recovery efficiency of the produced gas. Content of the Utility Model

[0005] In view of the above problems, the utility model provides an optimized system for surface oil and gas gathering and transportation in the production section of gas flooding development in low-permeability oilfields.

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

[0007] An optimized system for surface oil and gas gathering and transportation in the production section of gas flooding development in low-permeability oilfields includes a wellhead, an oil-water separation tank connected to the wellhead through an oil transportation main pipeline, a gas purification tank connected to the wellhead through a gas transportation main pipeline. The end of the oil-water separation tank is sequentially connected to a well site storage oil tank and a joint station through a long-distance oil transportation pipeline. The end of the gas purification tank is respectively connected to a first separation tank and a second separation tank through a long-distance gas transportation pipeline. The top of the oil-water separation tank is connected to the front and rear ends of the gas purification tank through a group of shunt pipes, and a purification component is arranged inside the gas purification tank.

[0008] Furthermore, a carbon dioxide monitor is provided in the middle of the long-distance gas pipeline. A three-way valve is provided in the long-distance gas pipeline behind the carbon dioxide monitor. The three-way valve divides the long-distance gas pipeline into two sections and is respectively connected to the first separation tank and the second separation tank. The setting of the three-way valve can adjust the gas flow direction, so as to adjust the flow direction of the produced gas according to the content of carbon dioxide in the produced gas monitored by the carbon dioxide monitor.

[0009] Furthermore, a mist eliminator is provided at the inner top of the oil-water separation tank. The mist eliminator is connected to the bottom of the shunt pipe. A water outlet pipe is provided at the bottom of the oil-water separation tank. The mist eliminator can further separate the oil in the mist.

[0010] Furthermore, the shunt pipe is divided into two sections. One section of the shunt pipe is communicated with the main gas pipeline at the front end of the gas purification tank, and the other section of the shunt pipe is communicated with the long-distance gas pipeline at the rear end of the gas purification tank. Solenoid valves are provided on both sections of the shunt pipe. Through the setting of the shunt pipe, the reflux direction of the reflux produced gas can be adjusted according to the content of carbon dioxide in the produced gas monitored by the carbon dioxide monitor.

[0011] Furthermore, the purification assembly includes a primary filter barrel for preliminarily filtering the produced gas. A sleeve is provided outside the primary filter barrel. The front end of the primary filter barrel is connected to the main gas pipeline. The distance between the inner wall of the sleeve and the outer wall of the primary filter barrel is 0.5 to 1 times the diameter of the primary filter barrel. A plurality of slots are provided in the circumferential direction of the sleeve. A secondary filter cover is rotatably sleeved outside the sleeve. Rotating rings are provided at both ends of the secondary filter cover. A plurality of filter plates are provided between the two rotating rings. The number of the filter plates corresponds to the number of the slots. A driving motor for driving the rotating ring to rotate is provided at the inner top of the gas purification tank. Through the setting of the purification assembly, the purification method can be adjusted according to the content of carbon dioxide in the produced gas monitored by the carbon dioxide monitor. When the carbon dioxide content in the produced gas is low, it indicates that there are more impurity gases. The filter plates are opened to strengthen the filtration. At other times, the filter plates do not need to be enabled, which improves the working life of the filter plates.

[0012] Furthermore, the number of the slots and the filter plates is 3 to 6. It can achieve a good filtration effect.

[0013] The beneficial effects of the present utility model are:

[0014] (1) The oil-gas gathering and transportation optimization system of the present utility model is specifically optimized for the production section of carbon dioxide injection for oil production. Different working modes are adjusted according to the different contents of carbon dioxide in the produced gas monitored by the carbon dioxide monitor, which improves the working efficiency, scientifically and reasonably distributes the flow direction of the produced gas, avoids resource waste, and improves the recovery of carbon dioxide and the purification of impurities in the produced gas;

[0015] (2) The purification component of the present utility model can adjust the purification method according to the content of carbon dioxide in the produced gas monitored by the carbon dioxide monitor. When the carbon dioxide content in the produced gas is low, it indicates that there are more impurity gases, and the filter plate is turned on to strengthen the filtration. At other times, the filter plate does not need to be enabled, which improves the working life of the filter plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of the system of the present utility model.

[0017] Figure 2 It is a schematic diagram of the internal structure of the oil-water separation tank and the gas purification tank of the present utility model.

[0018] Figure 3 It is a schematic diagram of the front structure of the purification component of the present utility model.

[0019] Figure 4 It is a schematic diagram of the back structure of the purification component of the present utility model.

[0020] Wherein, 1 - wellhead, 11 - main oil pipeline, 12 - main gas pipeline, 2 - oil-water separation tank, 21 - mist eliminator, 22 - water outlet pipe, 3 - gas purification tank, 4 - long-distance oil pipeline, 5 - well site storage oil tank, 6 - combined station, 7 - long-distance gas pipeline, 71 - first separation tank, 72 - second separation tank, 73 - carbon dioxide monitor, 74 - three-way valve, 8 - shunt pipe, 81 - solenoid valve, 9 - purification component, 91 - primary filter barrel, 92 - sleeve, 93 - slotted opening, 94 - rotating ring, 95 - filter plate, 96 - drive motor. SPECIFIC EMBODIMENTS

[0021] Embodiment 1

[0022] As Figure 1 、 2As shown in the figure, an optimized system for surface oil and gas gathering and transportation in the production section of gas flooding development in low-permeability oilfields includes a wellhead 1, an oil-water separation tank 2 connected to the wellhead 1 through an oil transmission main pipeline 11, a gas purification tank 3 connected to the wellhead 1 through a gas transmission main pipeline 12. The end of the oil-water separation tank 2 is successively connected to a wellsite storage oil tank 5 and a joint station 6 through a long-distance oil transmission pipeline 4. The end of the gas purification tank 3 is connected to a first separation tank 71 and a second separation tank 72 respectively through a long-distance gas transmission pipeline 7. A carbon dioxide monitor 73 is provided in the middle of the long-distance gas transmission pipeline 7. A three-way valve 74 is provided in the long-distance gas transmission pipeline 7 behind the carbon dioxide monitor 73. The three-way valve 74 divides the long-distance gas transmission pipeline 7 into two sections and is respectively connected to the first separation tank 71 and the second separation tank 72. The top of the oil-water separation tank 2 is connected to the front and rear ends of the gas purification tank 3 respectively through a group of shunt pipes 8. A mist eliminator 21 is provided at the inner top of the oil-water separation tank 2. The mist eliminator 21 is connected to the bottom of the shunt pipe 8. A water outlet pipe 22 is provided at the bottom of the oil-water separation tank 2. The shunt pipe 8 is divided into two sections. One section of the shunt pipe 8 is communicated with the gas transmission main pipeline 12 at the front end of the gas purification tank 3, and the other section of the shunt pipe 8 is communicated with the long-distance gas transmission pipeline 7 at the rear end of the gas purification tank 3. Solenoid valves 81 are provided on both sections of the shunt pipe 8. A purification component 9 is provided inside the gas purification tank 3;

[0023] As Figure 2 , 3 , as shown in Figure 4, the purification component 9 includes a primary filter barrel 91 for preliminarily filtering the produced gas. A sleeve 92 is provided outside the primary filter barrel 91. The front end of the primary filter barrel 91 is connected to the gas transmission main pipeline 12. The distance between the inner wall of the sleeve 92 and the outer wall of the primary filter barrel 91 is 0.5 to 1 times the diameter of the primary filter barrel 91. Four slots 93 are provided circumferentially on the sleeve 92. A secondary filter cover is rotatably sleeved outside the sleeve 92. Rotating rings 94 are provided at both ends of the secondary filter cover. Four filter plates 95 are provided between the two rotating rings 94. The number of filter plates 95 corresponds to the number of slots 93. A driving motor 96 for driving the rotation of the rotating ring 94 is provided at the inner top of the gas purification tank 3. The driving motor 96 is a commercially available industrial gear reduction motor.

[0024] Embodiment 2

[0025] This embodiment is basically the same as Embodiment 1, and the difference lies in that the set numbers of the slots 93 and the filter plates 95 are different.

[0026] The numbers of the slots 93 and the filter plates 95 are 3.

[0027] Embodiment 3

[0028] This embodiment is basically the same as Embodiment 1, and the difference lies in that the set numbers of the slots 93 and the filter plates 95 are different.

[0029] The numbers of the slots 93 and the filter plates 95 are 6.

[0030] Working principle: The working principle of the optimized system of the present utility model will be briefly described below.

[0031] During use, the produced fluid enters the inside of the oil-water separation tank 2 through the main oil pipeline 11. The separated water is discharged through the water outlet pipe 22, and the separated oil enters the well site storage oil tank 5 through the long-distance oil pipeline 4 and finally enters the combined station 6.

[0032] The produced gas enters the inside of the purification component 9 through the main gas pipeline 12 after preliminary separation at the wellhead 1. First, it is filtered through the primary filter barrel 91, enters the inside of the gas purification tank 3 through the slotted opening 93 of the sleeve 92, and is then transported by the long-distance gas pipeline 7. At this time, the purification method is adjusted according to the carbon dioxide content in the produced gas monitored by the carbon dioxide monitor 73. If the monitored carbon dioxide content is greater than 72%, the produced gas enters the inside of the first separation tank 71 through the three-way valve 74, preparing to reinject the gas with a high carbon dioxide content. If the monitored carbon dioxide content is greater than 50% and less than 72%, the produced gas enters the inside of the second separation tank 72 through the three-way valve 74 to separate the carbon dioxide from the produced gas. If the monitored carbon dioxide content is less than 50%, it indicates that there are more impurity gases in the produced gas and further filtration is required. The driving motor 96 is started to drive the rotating ring 94 to rotate, so that the filter plate 95 blocks the position where the slotted opening 93 is located, and the produced gas must pass through the secondary filtration of the filter plate 95 before it can enter the inside of the gas purification tank 3 and be transported by the long-distance gas pipeline 7.

[0033] In addition, the produced gas remaining in the produced fluid discharged by the mist eliminator 21 inside the oil-water separation tank 2 enters the shunt pipe 8. Similarly, if the monitored carbon dioxide content is less than 50%, it indicates that there are more impurity gases in the produced gas, and the solenoid valve 81 on the corresponding main gas pipeline 12 is opened to return the residual produced gas to the gas purification tank 3 for deep purification treatment. If the monitored carbon dioxide content is greater than 50%, the solenoid valve 81 on the corresponding long-distance gas pipeline 7 is opened to directly return the residual produced gas to the long-distance gas pipeline 7.

Claims

1. A surface oil and gas gathering and transportation optimization system for the production section of a low-permeability oilfield gas drive development, characterized in that: The invention comprises a wellhead (1), an oil-water separation tank (2) connected to the wellhead (1) via an oil main pipeline (11), and a gas purification tank (3) connected to the wellhead (1) via a gas main pipeline (12); the end of the oil-water separation tank (2) is connected to a well site oil storage tank (5) and a joint station (6) in sequence via a long oil pipeline (4); the end of the gas purification tank (3) is connected to a first separation tank (71) and a second separation tank (72) via a long gas pipeline (7); the top of the oil-water separation tank (2) is connected to the front and rear ends of the gas purification tank (3) via a group of manifolds (8); and a purification component (9) is provided inside the gas purification tank (3).

2. The surface oil and gas gathering and transportation optimization system for low permeability oil field gas drive development and production section according to claim 1 is characterized in that: A carbon dioxide monitor (73) is provided in the middle of the long gas pipeline (7), and a three-way valve (74) is provided on the long gas pipeline (7) behind the carbon dioxide monitor (73). The three-way valve (74) divides the long gas pipeline (7) into two sections and is respectively connected to the first separation tank (71) and the second separation tank (72).

3. The surface oil and gas gathering and transportation optimization system for low permeability oil field gas drive development and production section according to claim 1 is characterized in that: A mist collector (21) is provided at the top of the oil-water separation tank (2), the mist collector (21) is connected to the bottom of the diversion pipe (8), and a water outlet pipe (22) is provided at the bottom of the oil-water separation tank (2).

4. The surface oil and gas gathering and transportation optimization system for low permeability oil field gas drive development and production section according to claim 1 is characterized in that: The diverter pipe (8) is divided into two sections, one section of the diverter pipe (8) is connected to the main gas transmission line (12) at the front end of the gas purification tank (3), and the other section of the diverter pipe (8) is connected to the long gas transmission line (7) at the rear end of the gas purification tank (3). Solenoid valves (81) are provided on both sections of the diverter pipe (8).

5. The surface oil and gas gathering and transportation optimization system for low permeability oil field gas drive development and production section according to claim 1 is characterized in that: The purification component (9) comprises a primary filter barrel (91) for preliminary filtering of produced gas, a sleeve (92) being provided outside the primary filter barrel (91), the front end of the primary filter barrel (91) being connected to the gas transmission main line (12), the distance between the inner wall of the sleeve (92) and the outer wall of the primary filter barrel (91) being 0.5 to 1 times the diameter of the primary filter barrel (91), a plurality of slots (93) being provided in the circumferential direction of the sleeve (92), a secondary filter cover being rotatably sleeved outside the sleeve (92), rotating rings (94) being provided at both ends of the secondary filter cover, a plurality of filter plates (95) being provided between the two rotating rings (94), the number of the filter plates (95) corresponding to the number of the slots (93), and a driving motor (96) for driving the rotating ring (94) to rotate.

6. The surface oil and gas gathering and transportation optimization system for the production section of low permeability oilfield gas drive development according to claim 5 is characterized in that: The number of the slots (93) and the filter plates (95) is 3 to 6.

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