Gas injectable submersible electric pump system

Abstract

The present application relates to the field of oil injection and production, and particularly relates to a gas injection submersible electric pump system, which comprises a gas injection switch, a tail pipe suspension system, a submersible electric pump and a wellhead sealing device. The gas injection switch comprises a reset spring installed at the bottom of the gas injection switch, a gas injection switch piston arranged above the reset spring and capable of sliding up and down in the gas injection switch, a plug for pressing down and sealing the gas injection switch piston, and a vent hole arranged on the side wall of the gas injection switch and connecting the internal cavity of the gas injection switch with the tail pipe suspension casing. The present application switches the gas injection and production modes through the gas injection switch, realizes high-pressure gas injection and production with the same pipe column, uses anticorrosive materials to prolong the service life of the submersible electric pump, improves the system sealing performance, and improves the operation efficiency and reduces the cost.

Description

Technical Field

[0001] This invention relates to the field of oil injection and production, and specifically to a gas-injectable submersible electric pump system. Background Technology

[0002] Submersible electric pumps (SAPs) play a crucial role in the artificial lift of heavy and extra-heavy oils due to their large displacement and high head. With the continued development of oil reservoirs, gas injection has become a primary method for increasing production after formation water cut rises. However, due to limitations such as oxygen corrosion during gas injection and pump pressure resistance, the SSP must be withdrawn before the gas injection tubing can be lowered, significantly impacting subsequent production efficiency and cost. Therefore, finding a way to directly inject gas to shut down the well and start production without withdrawing the SSP, thereby improving operational efficiency and reducing costs, is a problem that needs to be solved. Summary of the Invention

[0003] To address the problems of low operational efficiency and high operating costs caused by the inability of existing technologies to inject gas and produce oil without using a submersible electric pump, this invention provides a gas-injectable submersible electric pump system. The specific technical solution of this invention is as follows:

[0004] A gas-injectable submersible electric pump system is characterized by comprising a gas injection switch, a tailpipe suspension system, a submersible electric pump, and a wellhead sealing device.

[0005] The tailpipe suspension system includes a top tailpipe suspension connector for communicating with and sealing the outer periphery of the oil pipe, a hollow tailpipe suspension sleeve connected to the top tailpipe suspension connector, a tailpipe suspended at the bottom, and a cable. The top tailpipe suspension connector uses a V-shaped sealing gasket made of AFLAS material.

[0006] The air injection switch and submersible electric pump are located inside the tailpipe suspension sleeve. The air injection switch is a tubular structure, sealed at the top below the tailpipe suspension connector and connected to the oil pipe. Internally, it has a return spring at the bottom and an air injection switch piston located above the return spring, which can slide up and down within the air injection switch. The air injection switch piston has a through hole in the middle, and the inner wall of the upper part of the through hole is a conical surface with a diameter gradually increasing from bottom to top. The plug can be inserted into the through hole, forming a seal with the conical surface when the plug is inserted. A conical rubber sealing ring made of AFLAS material is provided on the surface of the plug that mates with the conical surface. The air injection switch also includes an exhaust port on the side wall that connects the internal cavity of the air injection switch to the tailpipe suspension sleeve. When the return spring is in the compressed state, the exhaust port is open; when the return spring is in the uncompressed state, the exhaust port is sealed by the air injection switch piston.

[0007] The submersible pump and the cable are made of stainless steel.

[0008] The wellhead sealing device uses a flange and through-bar structure. The through-bar and the flange are sealed with an O-ring, and the O-ring is made of AFLAS material.

[0009] This invention switches between gas injection and production modes by depressing and resetting the gas injection switch piston within the gas injection switch, enabling high-pressure gas injection and production within the same tubing string even when not in operation. This invention extends the service life of the submersible pump (SPMP) through the following methods: the plug seals the gas injection switch piston during gas injection, preventing high-pressure gas from entering the SPMP; the anti-gas lock reduces the impact of free nitrogen in the oil on the SPMP; and the use of stainless steel improves the corrosion resistance of the SPMP and the cable. This invention utilizes a tailpipe suspension joint with a stainless steel pipe and V-shaped gasket combined sealing structure, a flange and through-bar structure, and a wellhead sealing device sealed with four O-rings, improving the sealing performance of the gas-injectable SPMP system and increasing operational efficiency. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the invention during gas injection;

[0011] Figure 2 This is a schematic diagram of the gas injection switch during gas injection;

[0012] Figure 3 This is a schematic diagram of the invention during production;

[0013] Figure 4 This is a schematic diagram of the gas injection switch during production.

[0014] The labels on the attached drawings are as follows: 1-Production pipeline; 2-Earth conditioner; 3-Diluentizing pipeline; 4-Tailpipe suspension connector; 5-Tailpipe suspension casing; 6-Submersible electric pump; 7-Tailpipe; 8-Wellhead sealing device; 9-Cable; 10-Gas injection switch; 11-Anti-gas lock; 12-Plug; 13-Gas injection switch piston; 14-Reset spring; 15-Exhaust port. Detailed Implementation

[0015] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0016] The present invention discloses a gas-injectable submersible electric pump system, including a gas injection switch 10 for controlling the gas injection and production mode and protecting the submersible electric pump, a tailpipe suspension system for supporting and sealing, a submersible electric pump 6 with an anti-gas lock 11 located inside the tailpipe suspension system for lifting crude oil, and a wellhead sealing device 8 for sealing the wellhead.

[0017] The tailpipe suspension system includes a tailpipe suspension upper connector 4 located at the top for communicating with and sealing the outer periphery of the oil pipe, a hollow tailpipe suspension sleeve 5 connected to the tailpipe suspension upper connector, a tailpipe 7 suspended at the bottom, and a cable 9.

[0018] The air injection switch 10 and the submersible electric pump 6 are located inside the tailpipe suspension sleeve 5. The air injection switch 10 is a tubular structure, with its top sealed and connected to the tailpipe suspension upper connector 4 below and communicating with the oil pipe. Inside, there is a return spring 14 at the bottom and an air injection switch piston 13 above the return spring 14 that can slide up and down inside the air injection switch. The air injection switch piston 13 has a through hole in the middle. The inner wall of the upper part of the through hole is a conical surface with a diameter that gradually increases from bottom to top. The through hole and the conical surface are both corresponding to the plug 12. A conical rubber sealing ring is provided on the surface of the plug 12 that mates with the conical surface. The sealing ring is made of AFLAS material. The plug 12 can be embedded in the through hole and form a seal with the conical surface. The air injection switch 10 also includes an exhaust port 15 disposed on the side wall, which connects the internal cavity of the air injection switch 10 with the tailpipe suspension sleeve 5. When the return spring 14 is in the pressed state, the exhaust port 15 is connected, and when the return spring 14 is in the unpressed state, the exhaust port 15 is sealed by the air injection switch piston 13.

[0019] The process of electric pump air injection is as follows Figure 1 and Figure 2 As shown, a plug 12 is inserted into the well through the top of the tree 2, and the plug 12 falls into the gas injection switch 10. The tail of the plug 12 enters the through hole in the middle of the gas injection switch piston 13. The plug 12 is also equipped with a conical rubber sealing ring made of AFLAS material. The sealing ring and the conical surface on the upper surface of the gas injection switch piston 13 form a seal, isolating the submersible pump 6. When gas is injected, the high-pressure gas pushes the plug 12 and the gas injection switch piston 13 downwards until the vent hole 15 is exposed. At this time, the gas injection switch 10 switches to the gas injection mode, and the high-pressure gas is injected directly into the bottom of the well through the vent hole 15 of the gas injection switch 10, the tailpipe suspension system, and the tailpipe 7, thereby realizing high-pressure gas injection in the electric pump well without operation.

[0020] The process of electric pump production is as follows Figure 3 and Figure 4 As shown, after the gas injection stops, the reset spring 14 inside the gas injection switch 10 pushes the gas injection switch piston 13 upward to reset, the vent 15 is sealed, and then the blockage 12 is removed using a retrieval tool. At this time, the production process is resumed, and thin oil is injected through the dilution pipe 3. The submersible electric pump 6 can be turned on to lift the oil to the production pipe 1, thereby achieving the purpose of quickly resuming production after the gas injection is completed, realizing production without operation.

[0021] This enables dual-process operation of high-pressure gas injection and production within the same tubing column without requiring actual operation.

[0022] The present invention uses a corrosion-resistant submersible electric pump 6 and a cable 9 made of stainless steel, which improves the overall corrosion resistance of the submersible electric pump 6 and extends its service life.

[0023] The anti-gas lock 11 is located in the middle of the submersible electric pump 6, which can reduce the impact of free nitrogen gas after gas injection on the submersible electric pump 6, ensure stable production of the submersible electric pump 6, and extend its service life.

[0024] The tailpipe suspension connector 4 utilizes an innovative combined sealing structure of stainless steel pipe and gasket. The gasket has been improved to a V-shaped structure, resulting in more uniform expansion under pressure. The rubber material is preferably AFLAS, which offers superior corrosion resistance against heavy oil, enhancing the sealing performance of the tailpipe suspension system. The wellhead sealing device 8 innovatively employs a flange and through-bar structure. The through-bar and flange are sealed with four O-rings made of AFLAS, significantly improving the wellhead through-bar sealing capability. These methods enhance the overall system's sealing performance and improve operational efficiency.

[0025] It should be noted that the specific embodiments described above enable those skilled in the art to more fully understand the present invention, but do not limit the present invention in any way. Therefore, although the present invention has been described in detail with reference to the accompanying drawings and embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the present invention. In short, all technical solutions and improvements that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the present invention patent.

Claims

1. A gas-injectable submersible electric pump system, characterized in that... This includes the gas injection switch, tailpipe suspension system, submersible electric pump, and wellhead sealing device; The tailpipe suspension system includes a tailpipe suspension upper connector located at the top for communicating with and sealing the outer periphery of the oil pipe, a hollow tailpipe suspension sleeve connected to the tailpipe suspension upper connector, a tailpipe suspended at the bottom, and a cable. The air injection switch and the submersible electric pump are located inside the tailpipe suspension sleeve. The air injection switch is a tubular structure with its top sealed and connected to the lower part of the tailpipe suspension connector and the oil pipe. It has a return spring at the bottom and an air injection switch piston above the return spring that can slide up and down inside the air injection switch. The air injection switch piston has a through hole in the middle, into which the plug can be inserted. The air injection switch also includes an exhaust hole on the side wall that connects the internal cavity of the air injection switch to the tailpipe suspension sleeve. When the return spring is in the compressed state, the exhaust hole is open, and when the return spring is in the uncomfortable state, the exhaust hole is sealed by the air injection switch piston.

2. The gas-injectable submersible electric pump system according to claim 1, characterized in that... The submersible pump and the cable are made of stainless steel.

3. The gas-injectable submersible electric pump system according to claim 1, characterized in that... The tailpipe suspension connector uses a V-shaped sealing gasket, and the V-shaped sealing gasket is made of AFLAS material.

4. The gas-injectable submersible electric pump system according to claim 1, characterized in that... The wellhead sealing device uses a flange and through-bar structure. The through-bar and the flange are sealed with an O-ring, and the O-ring is made of AFLAS material.

5. The gas-injectable submersible electric pump system according to claim 1, characterized in that, The inner wall of the upper part of the through hole is a conical surface with a diameter that gradually increases from bottom to top, and the plug forms a seal with the conical surface when it is inserted into the through hole.

6. The gas-injectable submersible electric pump system according to claim 5, characterized in that... A conical rubber sealing ring is provided on the surface of the plug that mates with the conical surface, and the sealing ring is made of AFLAS material.

7. The gas-injectable submersible electric pump system according to claim 1, characterized in that... The submersible electric pump is equipped with an anti-air lock.

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