Novel electric submersible pump lifting string structure

Abstract

This invention belongs to the technical field of rodless lift in deep / ultra-deep well oil production, specifically relating to a novel submersible electric pump lift string structure, aiming to solve the problem of insufficient well fluid lift capacity in ultra-deep wells. The invention includes an upper tubing arranged in the casing, an upper electric pump connected to the lower end of the upper tubing, a conversion assembly connected to the lower end of the upper electric pump, and a lower electric pump connected to the lower end of the conversion assembly; the upper tubing, the upper electric pump connected to the upper tubing, the conversion assembly connected to the upper electric pump, and the lower electric pump are linearly connected and interconnected; the conversion assembly includes an upper connecting pipe connected to the lower end of the upper electric pump, a packer connected to the upper connecting pipe and having an internal conversion channel, and a lower connecting pipe connected to the conversion channel within the packer; the lower connecting pipe is connected and interconnected with the lower electric pump. This invention employs a relay lift method to relay lift the well fluid in ultra-deep wells, enabling greater pressure to lift the well fluid to the surface during extraction, thereby improving the well fluid transportation efficiency.

Description

Technical Field

[0001] This invention relates to the technical field of rodless lift for deep / ultra-deep well oil production, specifically to a novel submersible electric pump lift string structure. Background Technology

[0002] With the rapid development of drilling technology in my country, the number of ultra-deep and extra-deep wells being drilled is increasing. Currently, the fluid level of some ultra-deep and extra-deep wells has reached over 4,000 meters. As mining continues, the dynamic fluid level will continue to decrease, and the number of ultra-deep and extra-deep wells with fluid levels exceeding 4,000 meters will continue to increase.

[0003] However, during the transportation of well fluid, the oil pump is installed at a great depth, resulting in a long oil pipe that extends deep underground. As the well fluid is pumped into the oil pipe, the pressure decreases continuously during the ascent, leading to insufficient lifting capacity and preventing the fluid from reaching the surface smoothly. Summary of the Invention

[0004] To address the aforementioned problems in the prior art, namely the insufficient lifting capacity of well fluid in ultra-deep wells, this invention provides a novel submersible electric pump lifting string structure.

[0005] This application discloses a novel submersible electric pump lift string structure, which adopts the following technical solution:

[0006] A novel submersible electric pump lifting string structure includes an upper oil pipe arranged in a casing, an upper electric pump connected to the lower end of the upper oil pipe, a conversion assembly connected to the lower end of the upper electric pump, and a lower electric pump connected to the lower end of the conversion assembly; in the casing, the upper oil pipe, the upper electric pump connected to the upper oil pipe, the conversion assembly connected to the upper electric pump, and the lower electric pump are linearly connected and interconnected.

[0007] The conversion assembly includes an upper connecting pipe connected to and communicating with the lower end of the upper electric pump, a packer communicating with the upper connecting pipe and having a conversion channel inside, and a lower connecting pipe communicating with the conversion channel inside the packer; the lower connecting pipe is connected to and communicating with the lower electric pump.

[0008] By adopting the above technical solution, the lower electric pump is first started. The lower electric pump pressurizes and extracts the well fluid at its location, and delivers the extracted well fluid to the conversion channel opened on the packer of the conversion assembly. The lower electric pump lifts the fluid to a height of approximately 3000 meters. Due to the seal between the packer and the casing, the well fluid will be in the conversion channel on the packer. As the lifting capacity increases, the fluid level in the conversion channel continuously rises and enters the upper part of the packer. Since the lifting capacity of the lower electric pump is limited, when the sensor detects that the pressure of the well fluid in the upper part of the packer reaches the design value, the upper electric pump is automatically started to carry out relay lifting. The upper electric pump extracts and lifts the well fluid in the upper part of the packer, and lifts it again by 3000 meters through the upper tubing, lifting the well fluid to the wellhead, thus achieving relay lifting and achieving the purpose of lifting to depths of 6000 meters and above in ultra-deep wells.

[0009] By setting up a new type of submersible electric pump lifting string structure and adopting a relay lifting method, the well fluid in ultra-deep wells is lifted in a relay manner, so that the well fluid can be lifted to the surface with greater pressure during the well fluid extraction process, thereby improving the well fluid transportation efficiency.

[0010] Optionally, the upper connecting pipe is connected to the upper electric pump via a threaded connection or a flange connection; the upper end of the lower connecting pipe is connected to the lower end of the packer via a threaded connection or a flange connection; and the lower end of the lower connecting pipe is connected to the upper end of the lower electric pump via a threaded connection or a flange connection.

[0011] By adopting the above technical solution, the assembly and connection of the lifting column structure can be facilitated.

[0012] Optionally, the packer is an up-and-down packer.

[0013] By adopting the above technical solution, it is convenient to install the packer in the designated position in the casing.

[0014] Optionally, a sensor is provided in the upper connecting pipe, and the sensor is electrically connected to the upper electric pump.

[0015] By adopting the above technical solution, the sensor controls the automatic start of the electric pump.

[0016] Optionally, the sensor is a pressure sensor.

[0017] By adopting the above technical solution, the sensor can more easily monitor the amount of well fluid in the conversion channel and control the start-up of the electric pump.

[0018] Optionally, the packer is provided with a pressure relief hole that penetrates the packer, and a pressure relief valve is installed on the upper side of the pressure relief hole, with the pressure relief valve arranged in the pressure relief hole.

[0019] By adopting the above technical solution, the oil well will produce some gas during the lifting process. The gas will affect the pump efficiency of the electric pump. Therefore, a pressure relief hole and a pressure relief valve are installed at the packer. When the pressure reaches the set value, the pressure will be automatically relieved.

[0020] Optionally, the pressure relief valve is a one-way valve.

[0021] The beneficial effects of this invention are:

[0022] (1) By setting up a new type of submersible electric pump lifting tubing structure and adopting a relay lifting method, the well fluid in the ultra-deep well is relayed to lift the well fluid to the surface during the well fluid extraction process, thereby improving the well fluid transportation efficiency.

[0023] (2) By setting up a pressure relief design, it is convenient to carry out downhole pressure relief. Attached Figure Description

[0024] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0025] Figure 1 This is a schematic diagram of the novel submersible electric pump lift string structure in this embodiment.

[0026] Explanation of reference numerals in the attached diagram: 1. Upper oil pipe; 2. Upper electric pump; 3. Conversion assembly; 31. Upper connecting pipe; 32. Packer; 33. Lower connecting pipe; 34. Conversion channel; 35. Pressure relief hole; 36. Pressure relief valve; 4. Lower electric pump; 5. Sensor. Detailed Implementation

[0027] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0028] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0029] This invention provides a novel submersible electric pump lift string structure. (Refer to...) Figure 1The novel submersible electric pump lifting string structure includes an upper oil pipe 1 arranged in the casing, an upper electric pump 2 connected to the lower end of the upper oil pipe 1, a conversion assembly 3 connected to the lower end of the upper electric pump 2, and a lower electric pump 4 connected to the lower end of the conversion assembly 3. In the casing, the upper oil pipe 1, the upper electric pump 2 connected to the upper oil pipe 1, the conversion assembly 3 connected to the upper electric pump 2, and the lower electric pump 4 are linearly connected and interconnected, and the lower electric pump 4 extends more than 4,000 meters underground.

[0030] One end of the upper oil pipe 1 is connected to the ground, and the other end extends into the casing and is located below the ground.

[0031] The upper electric pump 2 is fixedly connected to the upper oil pipe 1 at one end located below ground, and the upper electric pump 2 is connected to the upper oil pipe 1.

[0032] The conversion assembly 3 includes an upper connecting pipe 31, a packer 32, and a lower connecting pipe 33. The upper end of the upper connecting pipe 31 is connected to the lower end of the upper electric pump 2, and the upper connecting pipe 31 is connected to the inlet of the upper electric pump 2. The upper connecting pipe 31 can be connected to the upper electric pump 2 via a threaded connection or a flange connection. The packer 32 is arranged in a sleeve, and the packer 32 is designed for easy placement within the sleeve. A conversion channel 34 is provided in the packer 32, and the upper end of the conversion channel 34 is connected to the lower end of the upper connecting pipe 31. The upper end of the lower connecting pipe 33 is connected to the lower end of the packer 32, and the upper end of the lower connecting pipe 33 is connected to the lower end of the conversion channel 34. The upper end of the lower connecting pipe 33 and the lower end of the packer 32 can be connected via a threaded connection or a flange connection, thus achieving connection and communication between the lower connecting pipe 33 and the packer 32. The lower end of the lower connecting pipe 33 can be connected to the upper end of the lower electric pump 4 by means of threaded connection or flange connection, and the lower connecting pipe 33 is connected to the outlet of the lower electric pump 4, thereby realizing the connection between the lower electric pump 4, the lower connecting pipe 33, the conversion channel 34 of the packer 32, the upper connecting pipe 31, the upper electric pump 2, and the upper oil pipe 1.

[0033] Sensor 5 is installed in the upper connecting pipe 31. Sensor 5 is electrically connected to the upper electric pump 2. Sensor 5 is a pressure sensor used to detect the pressure in the conversion channel 34.

[0034] In addition, a pressure relief hole 35 is provided on the packer 32, the pressure relief hole 35 penetrates the packer 32, and a pressure relief valve 36 is installed on the upper side of the pressure relief hole 35. The pressure relief valve 36 is arranged in the pressure relief hole 35 and is a one-way valve.

[0035] The working process of the novel submersible electric pump lift string structure disclosed in this application is as follows: First, the lower electric pump 4 is started, and the lower electric pump 4 pressurizes and extracts the well fluid at its location. The extracted well fluid is transported to the conversion channel 34 opened on the packer 32 of the conversion component 3. The lower electric pump 4 lifts to a height of about 3000 meters. Since the packer 32 is sealed with the casing, the well fluid will be in the conversion channel 34 on the packer 32. As the lifting capacity increases, the liquid level in the conversion channel 34 continuously rises and enters the upper part of the packer 32. Since the lifting capacity of the lower electric pump 4 is limited, when the sensor 5 detects that the pressure of the well fluid in the upper part of the packer 32 reaches the design value, the upper electric pump 2 is automatically started to carry out relay lifting. The upper electric pump 2 extracts and lifts the well fluid in the upper part of the packer 32, and lifts it again by 3000 meters through the upper tubing 1, lifting the well fluid to the wellhead, realizing relay lifting, and achieving the purpose of lifting ultra-deep wells of 6000 meters and above. During the lifting process, the oil well will produce some gas, which will affect the pumping efficiency of the lower electric pump 4. Therefore, a pressure relief hole 35 and a pressure relief valve 36 are provided at the packer 32 to automatically relieve pressure when the pressure reaches the set value.

[0036] By setting up a new type of submersible electric pump lifting string structure and adopting a relay lifting method, the well fluid in ultra-deep wells is lifted in a relay manner, so that the well fluid can be lifted to the surface with greater pressure during the well fluid extraction process, thereby improving the well fluid transportation efficiency.

[0037] The term "comprising" or any other similar term is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus / device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent in such process, method, article, or apparatus / device.

[0038] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A novel submersible electric pump lifting string structure, characterized in that: It includes an upper oil pipe (1) arranged in the casing, an upper electric pump (2) connected to the lower end of the upper oil pipe (1), a conversion assembly (3) connected to the lower end of the upper electric pump (2), and a lower electric pump (4) connected to the lower end of the conversion assembly (3); in the casing, the upper oil pipe (1), the upper electric pump (2) connected to the upper oil pipe (1), the conversion assembly (3) connected to the upper electric pump (2), and the lower electric pump (4) are linearly connected and interconnected; The conversion assembly (3) includes an upper connecting pipe (31) connected to and communicating with the lower end of the upper electric pump (2), a packer (32) communicating with the upper connecting pipe (31) and having a conversion channel (34) inside, and a lower connecting pipe (33) communicating with the conversion channel (34) inside the packer (32); the lower connecting pipe (33) is connected to and communicating with the lower electric pump (4).

2. The novel submersible electric pump lifting string structure according to claim 1, characterized in that: The upper connecting pipe (31) is connected to the upper electric pump (2) by means of threaded connection or flange connection; the upper end of the lower connecting pipe (33) is connected to the lower end of the packer (32) by means of threaded connection or flange connection; the lower end of the lower connecting pipe (33) is connected to the upper end of the lower electric pump (4) by means of threaded connection or flange connection.

3. The novel submersible electric pump lift string structure according to claim 1, characterized in that: The packer (32) is an upward-lifting and downward-lowering packer (32).

4. The novel submersible electric pump lift string structure according to claim 1, characterized in that: A sensor (5) is installed in the upper connecting pipe (31), and the sensor (5) is electrically connected to the upper electric pump (2).

5. The novel submersible electric pump lift string structure according to claim 4, characterized in that: Sensor (5) is a pressure sensor.

6. The novel submersible electric pump lift string structure according to claim 1, characterized in that: The packer (32) has a pressure relief hole (35) that penetrates the packer (32), and a pressure relief valve (36) is installed on the upper side of the pressure relief hole (35). The pressure relief valve (36) is arranged in the pressure relief hole (35).

7. The novel submersible electric pump lift string structure according to claim 6, characterized in that: The pressure relief valve (36) is a one-way valve.

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