CN112855085A

CN112855085A - Submersible direct-drive screw pump gas lift composite lifting process suitable for offshore low-yield well

Info

Publication number: CN112855085A
Application number: CN202110072557.6A
Authority: CN
Inventors: 杨志; 郑浩然; 康露; 曾润; 陈杰; 陈勇
Original assignee: Southwest Petroleum University
Current assignee: Southwest Petroleum University
Priority date: 2021-01-20
Filing date: 2021-01-20
Publication date: 2021-05-28

Abstract

The invention relates to the field of petroleum and gas exploitation, and discloses an oil-submersible direct-drive screw pump gas-lift composite lifting process suitable for a marine low-yield well. The submersible direct-drive screw pump gas lift composite lifting process disclosed by the invention solves the problem of low lifting efficiency of the offshore low-yield well, saves the platform space, reduces the gas injection amount, improves the platform output pressure and output distance, and has practical significance for the exploitation of the offshore low-yield well.

Description

Submersible direct-drive screw pump gas lift composite lifting process suitable for offshore low-yield well

Technical Field

The invention relates to an air-entrapping and lifting composite lifting process of a submersible direct-drive screw pump, which is suitable for an offshore low-yield well.

Background

With the fact that part of oil fields produced at sea enter the middle and later period of production, the stratum productivity is continuously reduced, the production is lowered, and part of low-yield wells face the difficulty of production due to the fact that a proper artificial lifting mode is not available. In order to solve the exploitation problem of the low-yield well, the reasonable design of the proper lifting process is important for the characteristics of sand production, large well deviation, high gas-oil ratio and the like of the low-yield well of the offshore oil field. Compared with the same type of pump, the submersible direct-drive screw pump has good tolerance to gas, and the matched ground control device has the functions of stepless speed regulation, overvoltage, undervoltage, phase failure, over-temperature and the like. The gas lift technology has the advantages of simple wellhead and underground equipment, flexible lifting depth and displacement change, suitability for oil well conditions containing sand and corrosive media and the like. Therefore, the composite lifting process of the submersible direct-drive screw pump and the gas lift is provided to be applied to the exploitation of the offshore low-yield well.

Disclosure of Invention

The invention aims to overcome the defect that the traditional lifting process is applied to the exploitation of offshore low-yield wells, and provides a submersible direct-drive screw pump gas-lift composite lifting process suitable for offshore low-yield wells.

The technical scheme adopted by the invention is as follows:

the invention relates to an oil-submersible direct-drive screw pump gas-lift composite lifting process suitable for an offshore low-yield well.

Further, the gas injection pipeline penetrates through the upper centralizer, the lower centralizer and the upper packer and is fixed through the upper packer.

Furthermore, the oil pipe joint is used for connecting an installation oil pipe for installing the lower gas lift pipe column.

Furthermore, a suction inlet is arranged below the submersible speed reducer, so that well fluid flowing into the casing pipe enters the pump.

Furthermore, an upper check valve is arranged above the gas injection pipeline to prevent backflow.

Further, the gas injection pipeline is formed by connecting short pipes in a threaded mode.

Furthermore, the lower part of the submersible motor is provided with a supporting slip, and the lower centralizer plays a role in centralizing and reducing vibration for the submersible motor by clamping the supporting slip.

Furthermore, a lower single-flow valve is arranged on the lower gas lift pipe column to prevent well fluid from flowing into the lower oil pipe from the oil pipe joint.

Furthermore, a motor protector is arranged at the upper part of the submersible motor to play a role in protecting the submersible motor.

Furthermore, the upper part of the suction inlet is provided with an oil-submersible speed reducer which plays a role in speed reduction and buffering of the entering well fluid.

Furthermore, the upper packer and the lower packer act together to clamp the lower oil pipe so as to suspend the lower oil pipe in the casing.

The invention has the beneficial effects that:

1. the invention increases the gas injection depth, eliminates eccentric wear of the rod pipe fundamentally and improves the system efficiency;

2. according to the invention, because no oil pipe is connected between the two lifting technologies, the gas lift maintenance period is long, all pipe columns do not need to be lifted when the submersible direct-drive screw pump is maintained, and the maintenance cost is low;

3. the invention can adjust the discharge capacity of the submersible direct-drive screw pump through the ground control system matched with the submersible direct-drive screw pump, and is easy to match with the discharge capacity interval of the gas lift technology;

4. the invention is a composite lifting process, reduces the lifting height of the gas lift and the gas injection pressure of the gas lift;

5. according to the invention, the submersible direct-drive screw pump is used for pressurizing the well fluid again, so that the output pressure and the output distance of the platform are increased, and the space of the platform output supercharger and the operation and maintenance cost are saved.

Drawings

FIG. 1: the invention discloses a schematic diagram of a submersible direct-drive screw pump gas lift composite lifting process pipe column;

the attached drawings are marked as follows: 1. the safety valve comprises a safety valve, 2, an upper check valve, 3, an upper centralizer, 4, a screw pump discharge port, 5, a rotor, 6, a stator, 7, an oil-submersible speed reducer, 8, a suction port, 9, an oil-submersible cable, 10, a motor protector, 11, an air injection pipeline, 12, an oil-submersible motor, 13, a supporting slip, 14, a lower centralizer, 15, an oil pipe joint, 16, an upper packer, 17, a lower check valve, 18, an air lift valve, 19, a casing pipe, 20, an oil pipe and 21, a lower packer

Detailed Description

The invention is further described below with reference to the accompanying drawings.

As shown in attached figure 1, the invention relates to an oil-submersible direct-drive screw pump gas-lift composite lifting process suitable for an offshore low-yield well, which mainly comprises a safety valve 1, an upper check valve 2, an upper centralizer 3, a screw pump discharge port 4, a rotor 5, a stator 6, an oil-submersible speed reducer 7, a suction inlet 8, an oil-submersible cable 9, a motor protector 10, a gas injection pipeline 11, an oil-submersible motor 12, a supporting slip 13, a lower centralizer 14, an oil pipe joint 15, an upper packer 16, a lower check valve 17, a gas lift valve 18, a casing pipe 19, an oil pipe 20 and a lower packer 21 from top to bottom in sequence. Wherein the tubing joint 15 is used for connecting an installation tubing for installing a lower gas lift string.

In the invention, the lower part of the submersible motor 12 is provided with a supporting slip 13, and the supporting slip 13 is clamped by a lower centralizer 14, thereby having the functions of centralizing and reducing vibration of the submersible motor 12.

In the present invention, the gas injection pipe 11 passes through the upper centralizer 3, the lower centralizer 14, and the upper packer 16, and is fixed by the upper packer 16.

In the invention, a suction inlet 8 is arranged below the submersible speed reducer 7, so that well fluid flowing into a casing 19 enters a pump.

In the present invention, the lower gas lift column is provided with a lower single flow valve 17 to prevent well fluid from flowing from the tubing joint 15 into the lower tubing 20.

In the present invention, the upper packer 16 and the lower packer 21 cooperate to retain the lower tubing 20 suspended in the casing 19. The pipe column installation process comprises the following steps: the installation oil pipe connected with the gas lift pipe column through an oil pipe joint 15 is put in, the lower part of the gas injection pipe 11 fixed in the upper packer 16 is also put in, the lower part of the gas injection pipe 11 is not provided with the check valve 2, after the lower part reaches the putting position, the upper packer 16 and the lower packer 21 are set to block the gas lift pipe column, the rotary installation oil pipe is disconnected from the connection with the gas lift pipe column, the installation oil pipe is lifted up, then the oil pipe with the submersible direct-drive screw pump pipe column structure is put in, the oil pipe is hung above the gas lift pipe column, the middle parts of the two pipe columns are not connected, finally the upper part of the gas injection pipe 11 with the upper check valve 2 is put in, and the upper part is in threaded connection with the lower part.

The specific implementation mode of the invention is as follows: gas is injected into an air injection pipeline 11, enters an annular space between an upper packer 16 and a lower packer 21, enters an oil pipe 20 through a gas lift valve 18, the density of well fluid is reduced, the gas lift process is completed, the well fluid flows upwards along the oil pipe 20, flows into a sleeve pipe 19 at an oil pipe joint 15, continues to flow upwards in the sleeve pipe 19, cools an oil submersible motor 12 in the sleeve pipe 19 in the flow process, enters an oil submersible speed reducer 7 through a suction inlet 8 when reaching the suction inlet 8, then enters a screw pump, is continuously pressurized in the pump through the rotation of a rotor 5 in a stator 6, is discharged from a screw pump discharge outlet 4, the oil submersible direct-drive screw pump lifting process is completed, and finally the well fluid flows towards the oil pipe.

The concrete connection mode of each part of the invention adopts conventional means such as mature bolts, rivets, welding and the like in the prior art, machinery, parts and equipment adopt conventional models in the prior art, and the connection adopts the conventional connection mode in the prior art, so that detailed description is omitted.

Claims

1. A submersible direct-drive screw pump gas-lifting compound lifting process suitable for offshore low-yield wells, which is mainly composed of a safety valve (1), an upper check valve (2), an upper centralizer (3), and a screw pump discharge. outlet (4), rotor (5), stator (6), submersible reducer (7), suction port (8), submersible cable (9), motor protector (10), gas injection pipe (11), Submersible motor (12), supporting slips (13), lower centralizer (14), oil pipe joint (15), upper packer (16), lower check valve (17), gas lift valve (18), The casing (19), the oil pipe (20), and the lower packer (21) are composed of the gas injection pipeline (11) passing through the upper centralizer (3), the lower centralizer (14), and passing through the upper packer (16) FIXED.

2. a kind of submersible direct drive screw pump gas lift compound lift technology suitable for offshore low-yield wells according to claim 1, it is characterized in that: described gas lift string is in submersible direct drive screw pump string the lower part, and there is no oil pipe (20) connection between the two lifting processes.