Ultra-long-range phase change huff and puff oil production unit

Abstract

An ultra-long-range phase change injection oil production device includes tubing that passes through a wellhead flange and is inserted into a casing. A crude oil outlet is located at the upper end of the tubing, and a lower check valve is located at the lower end, ensuring that water-bearing crude oil can only enter the tubing from the casing. A heating device is located inside the tubing, above the lower check valve, to heat the water-bearing crude oil entering the tubing and generate steam. A limiting sleeve is located at the lower part of the tubing, and a sliding lifter is supported on the limiting sleeve. The sliding lifter has a sliding clearance fit with the inner wall of the tubing and slides upward under the action of steam, thereby pushing the water-bearing crude oil upward. An upper check valve is located on the tubing, above the sliding lifter, ensuring that the water-bearing crude oil, after being pushed upward, can only enter the upper part of the tubing from bottom to top through the upper check valve. The advantages are: low mechanical wear throughout the operation, high reliability, long stroke of the sliding lifter, high working efficiency, and low operating noise; moreover, it eliminates the need for a wellhead heating device, resulting in low oil production costs.

Description

Technical Field

[0001] This invention pertains to oil production equipment, and particularly relates to an ultra-long-range phase change huff and puff oil production equipment. Background Technology

[0002] Currently, most oilfields in China are in the mid-to-late stages of oil production, resulting in high water content and low yields. The primary extraction method remains pumping units, which are the main lifting equipment in rod-type pumping systems. Based on the presence or absence of a walking beam, they can be categorized as beam-type or beamless pumping units. The main problems with pumping units include low extraction efficiency, short stroke, high mechanical wear, high operating noise, and environmental pollution. Furthermore, the extracted oil may sometimes be at low temperatures and condense, requiring auxiliary heating at the wellhead before it can be transported, which increases production costs and reduces efficiency. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide an ultra-long-range phase change injection oil production device with low mechanical wear, long stroke, high working efficiency, and no need for wellhead heating device.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] An ultra-long-range phase change injection oil production device includes a tubing that passes through a wellhead flange and is inserted into a casing. A crude oil outlet is located at the upper end of the tubing, and a lower check valve is located at the lower end of the tubing, allowing water-bearing crude oil to enter the tubing only from the casing. A heating device is located inside the tubing, above the lower check valve, to heat the water-bearing crude oil entering the tubing and generate steam. A limiting sleeve is located at the lower part of the tubing, and a sliding lifter is supported on the limiting sleeve. The sliding lifter has a sliding clearance fit with the inner wall of the tubing and is used to slide upwards under the action of steam, thereby pushing the water-bearing crude oil upwards.

[0006] An upper check valve is installed on the oil pipe above the sliding lift, so that the water-containing crude oil can only enter the upper part of the oil pipe from bottom to top through the upper check valve after being pushed up.

[0007] As a further preferred embodiment, the sliding lift includes a hollow shaft with a sliding assembly on it. The sliding assembly slides and clearances with the inner wall of the oil pipe. A linear motor is provided above the sliding assembly, and a sealing plug is provided at the output end of the linear motor for controlling the upper port switch of the hollow shaft.

[0008] As a further preferred embodiment, the sliding assembly is composed of multiple clamping plates and sliding sleeves arranged at intervals, the sliding sleeves being made of non-metallic wear-resistant material, and each sliding sleeve being clamped between two adjacent clamping plates.

[0009] As a further preferred embodiment, a mounting sleeve is connected to the sliding assembly, the linear motor is fixed inside the mounting sleeve, and multiple strip-shaped holes are evenly distributed on the outer wall of the mounting sleeve, allowing the water-containing crude oil to enter the upper part of the sliding assembly through the open sealing plug and the strip-shaped holes.

[0010] As a further preferred embodiment, a battery and a microcontroller are installed inside the mounting sleeve on top of the linear motor. The battery is electrically connected to the linear motor through the microcontroller to control the operation of the linear motor. A pressure sensor is installed on the sealing cover at the upper end of the mounting sleeve. The signal output terminal of the pressure sensor is connected to the microcontroller to detect the oil pressure on the sliding lift and transmit it to the microcontroller.

[0011] As a further preferred embodiment, an upper spring and a lower spring are respectively provided at the upper and lower ends of the sliding assembly. The upper spring is sleeved outside the mounting sleeve and is higher than the mounting sleeve, and is used to buffer the sliding lift when it slides to the upper and lower stops.

[0012] As a further preferred embodiment, a support sleeve is provided on the valve seat of the lower check valve, and the heating device is installed in the upper part of the support sleeve; strip-shaped notches are evenly distributed along the circumferential direction at the lower end of the support sleeve, so that the water-containing crude oil can enter the oil pipe through the lower check valve and the strip-shaped notches.

[0013] As a further preferred embodiment, the lower one-way valve is composed of a valve seat and a steel ball. The valve seat is connected to the lower end of the oil pipe by a threaded seal. A conical valve port is provided at the upper end of the central hole of the valve seat. The steel ball is located inside the conical valve port and can move up and down within the support sleeve.

[0014] As a further preferred embodiment, the heating device is an electric heater, whose power supply wire passes through the oil pipe seal and is connected to the power supply via a thermostat located on the wellhead flange.

[0015] The beneficial effects of this invention are as follows:

[0016] A heating device located inside the tubing, above the lower check valve, heats the water-bearing crude oil entering the tubing. This causes the water in the crude oil to turn into steam, which gradually expands in the lower part of the tubing. This steam pushes the sliding lift upwards along the tubing. The upward movement of the sliding lift pushes the water-bearing crude oil upwards and through the upper check valve into the upper part of the tubing. This process is repeated to push the water-bearing crude oil that has entered the upper part of the tubing out through the crude oil outlet at the upper end of the tubing. The entire working process has low mechanical wear, high reliability, long stroke of the sliding lift, high working efficiency, and low operating noise. Moreover, the extracted crude oil can flow and be transported smoothly without the need for a wellhead heating device, resulting in low oil production costs. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the present invention;

[0018] Figure 2 yes Figure 1 A magnified view of a portion of the image.

[0019] Figure 3 This is a circuit block diagram of a linear motor.

[0020] In the diagram: 1. Lower check valve; 2. Support sleeve; 3. Heating device; 4. Casing; 5. Oil pipe; 6. Limit sleeve; 7. Sliding lifter; 8. Pressure sensor; 9. Upper check valve; 10. Crude oil outlet; 11. Upper spring; 12. Mounting sleeve; 13. Linear motor; 14. Sealing plug; 15. Clamping plate; 16. Sliding sleeve; 17. Hollow shaft; 18. Lower spring; 19. Temperature controller; 20. Wellhead flange. Detailed Implementation

[0021] The invention will now be further described with reference to the accompanying drawings.

[0022] like Figure 1-3 As shown, the present invention relates to an ultra-long-range phase change injection oil production device, including an oil pipe 5 that passes through a wellhead flange 20 and is inserted into a casing 4. A crude oil outlet 10 is provided radially at the upper end of the oil pipe 5 and a valve is installed on the crude oil outlet 10. A lower check valve 1 is provided at the lower end of the oil pipe 5 so that water-containing crude oil can only enter the oil pipe 5 from the casing 4. A heating device 3 is provided inside the oil pipe 5 above the lower check valve 1 to heat the water-containing crude oil entering the oil pipe 5 and generate steam.

[0023] The lower one-way valve 1 is composed of a valve seat and a steel ball. The valve seat is connected to the lower end of the oil pipe 5 by a threaded seal. A conical valve port is provided at the upper end of the central hole of the valve seat. The steel ball is located inside the conical valve port and can move up and down inside the support sleeve 2.

[0024] The support sleeve 2 is fixed to the valve seat of the lower one-way valve 1. Multiple strip-shaped notches 201 are evenly distributed along the circumference at the lower end of the support sleeve 2, allowing water-bearing crude oil to enter the tubing 5 through the lower one-way valve 1 and the strip-shaped notches 201. The heating device 3 is installed in the upper part of the support sleeve 2. This heating device 3 is an electric heater, and its power supply wire passes through the support sleeve 2 and the tubing 5 in a sealed manner, and is connected to a power source via a temperature controller 19 located on the wellhead flange 20.

[0025] A limiting sleeve 6 is provided at the lower part of the oil pipe 5. External threads are provided at both ends of the limiting sleeve 6. The oil pipe 5 is disconnected at the limiting sleeve 6 and connected by a threaded seal through the limiting sleeve 6. A sliding lifter 7 is supported on the limiting sleeve 6 inside the oil pipe 5. The sliding lifter 7 is in sliding clearance fit with the inner wall of the oil pipe 5 and is used to slide upward under the action of steam, thereby pushing the water-containing crude oil upward. An upper one-way valve 9 is provided on the oil pipe 5 above the sliding lifter 7, so that the water-containing crude oil can only enter the upper part of the oil pipe 5 from bottom to top through the upper one-way valve 9 after being pushed upward.

[0026] The sliding lift 7 includes a hollow shaft 17, on which a sliding assembly is sleeved and fixed by a nut 21. The sliding assembly slides with a clearance fit against the inner wall of the oil pipe 5. A linear motor 13 is provided above the sliding assembly, and a sealing plug 14 is provided at the output end of the linear motor 13 for controlling the upper port switch of the hollow shaft 17. The sliding assembly is composed of multiple annular clamping plates 15 and sliding sleeves 16 arranged at intervals. In this embodiment, three clamping plates and two sliding sleeves are used as an example. The sliding sleeves 16 are made of non-metallic wear-resistant materials such as polytetrafluoroethylene, and each sliding sleeve 16 is clamped between two adjacent clamping plates 15.

[0027] An mounting sleeve 12 is threadedly connected to the clamping plate 15 at the upper end of the sliding assembly. The linear motor 13 is a small fixed shaft telescopic push rod motor and is fixed inside the mounting sleeve 12. Multiple strip holes are evenly distributed on the outer wall of the mounting sleeve 12, so that the water-containing crude oil can enter the upper part of the sliding assembly through the open sealing plug 14 and the strip holes.

[0028] A sealing cover is fixed to the upper end of the mounting sleeve 12. A high-temperature resistant battery and a microcontroller are installed inside the mounting sleeve 12 on the linear motor 13. The battery is electrically connected to the linear motor 13 through the microcontroller and is used to control the operation of the linear motor 13. An oil pressure sensor 8 is fixed on the sealing cover. The signal output terminal of the pressure sensor 8 is connected to the signal input terminal of the microcontroller and is used to detect the oil pressure on the sliding lift 7 and transmit it to the microcontroller.

[0029] An upper spring 11 and a lower spring 18 are fixed on the clamps at the upper and lower ends of the sliding assembly, respectively. The upper spring 11 is sleeved outside the mounting sleeve 12 and is higher than the mounting sleeve 12, and is used to buffer the sliding lift 7 when it slides to the upper stop point and the lower stop point.

[0030] The upper one-way valve 9 has the same structure as the lower one-way valve 1. Both ends of the valve seat of the upper one-way valve 9 are provided with external threads. The oil pipe 5 is disconnected at the valve seat of the upper one-way valve 9 and connected to the valve seat by thread sealing. The length of the oil pipe 5 between the lower one-way valve 1 and the limiting sleeve 6 is 2-10 meters, and the length of the oil pipe 5 between the limiting sleeve 6 and the upper one-way valve 9 is 100-500 meters, thereby realizing the ultra-long stroke of the sliding lift 7.

[0031] The steps for working are as follows:

[0032] 1. The water-containing crude oil in the casing 4 flows into the oil pipe 5 through the lower one-way valve 1. At the same time, since the sealing plug 14 of the sliding lift 7 is in the open state, the water-containing crude oil flows upward through the central hole of the hollow shaft 17. The pressure sensor 8 detects that the oil pressure value of the sliding lift 7 continues to increase until the liquid level in the oil pipe 5 is equal to that in the casing 4. The steel ball of the lower one-way valve 1 automatically falls back and closes by gravity.

[0033] 2. When the liquid levels in the oil pipe 5 and the casing 4 are equal, the pressure sensor 8 detects that the oil pressure on the sliding lift 7 has reached a stable value. The linear motor 13 is started by the microcontroller controller, which drives the sealing plug 14 to close the upper port of the hollow shaft 17, thus sealing and isolating the upper and lower spaces of the sliding lift 7.

[0034] 3. The heating device 3 is started by the thermostat to start heating rapidly. Since the heating device 3 is in the water-containing crude oil, as the heating temperature rises, the water in the water-containing crude oil gradually turns into steam. The volume of steam in the heating space at the bottom of the oil pipe 5 gradually expands, pushing the sliding lift 7 to slide upward and pushing the water-containing crude oil liquid above it to move upward and flow through the upper one-way valve 9 to the top of the upper one-way valve 9.

[0035] 4. Until the sliding lift 7 can no longer move upward after being pushed up by the upper spring 11 against the upper one-way valve 9, the steel ball of the upper one-way valve 9 will automatically close by gravity. At this time, the heating device 3 will stop heating and steam will no longer be generated.

[0036] 5. As the temperature decreases, the steam in oil pipe 5 gradually cools into water, and its volume gradually decreases. At this time, a pressure difference is formed between oil pipe 5 and casing 4, causing the water-containing crude oil to be automatically drawn into oil pipe 5 through the lower one-way valve 1 until the pressure inside and outside oil pipe 5 is balanced. At the same time, when the pressure sensor 8 detects that the oil pressure on the sliding lift 7 has reached the lower limit of the pressure setting, the microcontroller controller controls the linear motor 13 to start, driving the sealing plug 14 to open the upper port of the hollow shaft 17, and the sliding lift 7 automatically falls back to the limit sleeve 6 by its own gravity.

[0037] 6. Control the heating device 3 to reheat, repeat the above process until the water-bearing crude oil that has entered the upper part of the tubing 5 is pushed out of the tubing 5 through the crude oil outlet at the upper end of the tubing 5, thus achieving oil production. After repeating the cycle, stop production when the liquid level in the downhole casing 4 is lower than the limit sleeve 6 of the heating space, and resume production after the liquid level recovers.

[0038] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An ultra-long-range phase change huff-and-puff oil recovery device, characterized in that: The system includes tubing that passes through the wellhead flange and is inserted into the casing. A crude oil outlet is located at the upper end of the tubing, and a lower check valve is located at the lower end, ensuring that water-bearing crude oil can only enter the tubing from the casing. A heating device is located inside the tubing, above the lower check valve, to heat the water-bearing crude oil entering the tubing and generate steam. A limiting sleeve is located at the lower part of the tubing, and a sliding lifter is supported on the limiting sleeve. The sliding lifter has a sliding clearance fit with the inner wall of the tubing and is used to slide upwards under the action of steam, thereby pushing the water-bearing crude oil upwards. An upper check valve is installed on the oil pipe above the sliding lift, so that the water-containing crude oil can only enter the upper part of the oil pipe from bottom to top through the upper check valve after being pushed up. The sliding lift includes a hollow shaft with a sliding assembly on it. The sliding assembly slides and clearance-fits with the inner wall of the oil pipe. A linear motor is located above the sliding assembly and is controlled by a microcontroller. A sealing plug is provided at the output end of the linear motor to control the upper port switch of the hollow shaft. A pressure sensor is located at the upper end of the sliding lift. Its working principle is as follows: (1) The water-containing crude oil in the casing flows into the oil pipe through the lower check valve. At the same time, because the sealing plug of the sliding lift is in the open state, the water-containing crude oil flows upward through the central hole of the hollow shaft. The pressure sensor detects that the oil pressure value of the sliding lift continues to increase until the oil pipe and the liquid level in the casing are equal. The steel ball of the lower check valve automatically falls back and closes by gravity. (2) When the oil level in the tubing and the casing are equal, the pressure sensor detects that the oil pressure on the sliding lift has reached a stable value. The linear motor is started by the microcontroller, which drives the sealing plug to close the upper port of the hollow shaft, thus sealing and isolating the upper and lower spaces of the sliding lift. (3) The heating device is started by controlling the thermostat to start heating rapidly. Since the heating device is in the water-containing crude oil, as the heating temperature rises, the water in the water-containing crude oil gradually turns into steam. The volume of steam in the heating space at the bottom of the oil pipe gradually expands, pushing the sliding lift to slide upward and pushing the water-containing crude oil liquid above it to move upward and flow through the upper one-way valve to the top of the upper one-way valve. (4) Until the sliding lift reaches the upper check valve, the steel ball of the upper check valve will automatically close by gravity. At this time, the heating device will stop heating and steam will no longer be generated. (5) As the temperature drops, the steam in the oil pipe gradually cools into water and its volume gradually shrinks. At this time, a pressure difference is formed between the oil pipe and the casing, which causes the water-containing crude oil to be automatically drawn into the oil pipe through the lower check valve until the pressure inside and outside the oil pipe is balanced. At the same time, when the pressure sensor detects that the oil pressure on the sliding lift reaches the lower limit of the pressure setting, the single-chip microcomputer controller controls the linear motor to start, which drives the sealing plug to open the upper port of the hollow shaft. The sliding lift automatically falls back to the limit sleeve by its own gravity. (6) Control the heating device to reheat and repeat the above process until the water-containing crude oil that has entered the upper part of the tubing is pushed out of the tubing through the crude oil outlet at the upper end of the tubing to achieve oil production; after repeating the cycle, stop production when the liquid level in the downhole casing is lower than the limit sleeve position of the heating space, and continue production after the liquid level recovers to the height.

2. The ultra-long-range phase change huff-and-puff oil recovery device according to claim 1, characterized in that: The sliding assembly consists of multiple clamping plates and sliding sleeves arranged at intervals. The sliding sleeves are made of non-metallic wear-resistant material, and each sliding sleeve is clamped between two adjacent clamping plates.

3. The ultra-long-range phase change huff-and-puff oil recovery device according to claim 1, characterized in that: in A mounting sleeve is connected to the sliding assembly, and the linear motor is fixed inside the mounting sleeve. Multiple strip holes are evenly distributed on the outer wall of the mounting sleeve, allowing water-containing crude oil to enter the upper part of the sliding assembly through the open sealing plug and the strip holes.

4. The ultra-long-range phase change huff-and-puff oil recovery device according to claim 3, characterized in that: in Inside the mounting sleeve, above the linear motor, are a battery and a microcontroller. The battery is electrically connected to the linear motor via the microcontroller to control its operation. A pressure sensor is located on the sealing cover at the top of the mounting sleeve. The signal output of the pressure sensor is connected to the microcontroller to detect the oil pressure on the sliding lift and transmit it to the microcontroller.

5. The ultra-long-range phase change huff-and-puff oil recovery device according to any one of claims 1-4, characterized in that: in The sliding assembly has an upper spring and a lower spring at its upper and lower ends, respectively. The upper spring is sleeved outside the mounting sleeve and is higher than the mounting sleeve, and is used to buffer the sliding lift when it slides to the upper and lower stops.

6. The ultra-long-range phase change huff-and-puff oil recovery device according to claim 1, characterized in that: A support sleeve is provided on the valve seat of the lower check valve, and the heating device is installed in the upper part of the support sleeve; strip-shaped notches are evenly distributed along the circumference at the lower end of the support sleeve, so that the water-containing crude oil can enter the oil pipe through the lower check valve and the strip-shaped notches.

7. The ultra-long-range phase change huff-and-puff oil recovery device according to claim 1 or 6, characterized in that: The lower one-way valve is composed of a valve seat and a steel ball. The valve seat is connected to the lower end of the oil pipe by a threaded seal. A conical valve port is provided at the upper end of the central hole of the valve seat. The steel ball is located inside the conical valve port and can move up and down inside the support sleeve.

8. The ultra-long-range phase change huff-and-puff oil recovery device according to claim 1 or 6, characterized in that: The heating device is an electric heater, whose power supply wire passes through the oil pipe seal and is connected to the power supply via a thermostat located on the wellhead flange.

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