Continuous sand adding device for pressurized liquid carbon dioxide pipeline

Abstract

The invention belongs to the technical field of oil exploitation, and relates to an under-pressure liquid carbon dioxide pipeline continuous sand adding device which comprises a fracturing main pipe, a stirring kettle, a buffer tank, a liquid adding pipe, a material conveying assembly, a premixing main pipe, a plurality of feeding sand cylinders, a first pressurizing assembly and a plurality of second pressurizing assemblies. And the sand grains are preliminarily mixed with the high-pressure gaseous carbon dioxide after entering the premixing main pipe and enter the stirring kettle along with the high-pressure gaseous carbon dioxide. Gaseous carbon dioxide can be pressurized through the first pressurizing assembly to become high-pressure gaseous carbon dioxide, and sand grains are pressurized through each second pressurizing assembly, so that the sand grains are preliminarily mixed with the high-pressure gaseous carbon dioxide after entering the premixing main pipe and enter the stirring kettle along with the high-pressure gaseous carbon dioxide; the sand grains are mixed with the liquid carbon dioxide, continuous sand adding is carried out on the liquid carbon dioxide entering a fractured well, and the time needed by carbon dioxide dry sand adding fracturing is shortened.

Description

Technical Field

[0001] The invention belongs to the technical field of petroleum exploitation and relates to a continuous sand adding device for a pressurized liquid carbon dioxide pipeline. Background Art

[0002] Carbon dioxide dry fracturing with sand is a technology that uses liquid carbon dioxide as a fracturing fluid. Compared with water-based fracturing fluid, liquid carbon dioxide fracturing fluid has the advantages of less damage to reservoirs, strong fracture support ability, and high flowback efficiency. Liquid carbon dioxide dry fracturing technology has promoted the new development of fracturing technology and laid the foundation for the new development of oil and gas engineering applications.

[0003] At present, a sand mixing device is often used for carbon dioxide dry sand fracturing, including a tank body and a sand mixing pipe. The tank body is provided with a sand inlet and an air inlet. The inside of the tank body is in a high-pressure state. Sand particles are first loaded into the tank body from the sand inlet, and the sand inlet is closed to reduce the pressure leakage of the tank body. Then, gaseous carbon dioxide is filled into the tank body for cooling. After the sand particles and liquid carbon dioxide are mixed in the tank body, they are introduced into the sand mixing pipe and then introduced into the fracturing well through the sand mixing pipe.

[0004] However, since the tank body needs to maintain a high pressure state at all times, it needs to stop working each time the sand in the tank body is used up and can only work again after reloading the sand. This makes it impossible to add sand continuously during carbon dioxide dry sand fracturing, which increases the time required for carbon dioxide dry sand fracturing and reduces the working efficiency of carbon dioxide dry sand fracturing. Summary of the invention

[0005] The object of the present invention is to provide a pressurized liquid carbon dioxide pipeline continuous sand adding device, which can continuously add sand to hydraulic carbon dioxide during carbon dioxide dry sand adding fracturing, thereby reducing the time required for carbon dioxide dry sand adding fracturing.

[0006] To achieve the above purpose, the specific technical solution of a pressurized liquid carbon dioxide pipeline continuous sand adding device provided by the present invention is as follows:

[0007] A device for continuously adding sand to a pressurized liquid carbon dioxide pipeline comprises a fracturing main pipe, a stirring kettle and a buffer tank, wherein the fracturing main pipe is used to convey liquid carbon dioxide, the conveying front end of the fracturing main pipe is connected to the stirring kettle through a liquid adding pipe, the liquid adding pipe is used to convey part of the liquid carbon dioxide in the fracturing main pipe into the stirring kettle, the buffer tank stores gaseous carbon dioxide, the stirring kettle is connected to the conveying rear end of the fracturing main pipe through a material conveying assembly, the material conveying assembly is used to convey the mixed sand particles and liquid carbon dioxide into the fracturing main pipe, and further comprises:

[0008] The two ends of the premixing main pipe are connected to the stirring kettle and the buffer tank respectively;

[0009] A plurality of feeding sand cylinders are vertically and symmetrically arranged on both sides of the premixing main pipe, and the lower end of each feeding sand cylinder is connected to the premixing main pipe;

[0010] A first pressurizing component is disposed between the premixing main pipe and the buffer tank and is used to pressurize the gaseous carbon dioxide to convert the gaseous carbon dioxide into high-pressure gaseous carbon dioxide;

[0011] Multiple second pressurizing components correspond one to one with multiple feeding sand cylinders. Each second pressurizing component is arranged between the corresponding feeding sand cylinder and the premixing main pipe. Each second pressurizing component is used to pressurize the sand particles so that the sand particles are preliminarily mixed with the high-pressure gaseous carbon dioxide after entering the premixing main pipe and enter the mixing kettle along with the high-pressure gaseous carbon dioxide.

[0012] The present invention is also characterized in that:

[0013] The first pressurizing component includes: a compressor, which is arranged between the premixing main pipe and the buffer tank, wherein the input end of the compressor is connected to the buffer tank, and the output end of the compressor is connected to the other end of the premixing main pipe.

[0014] A connecting pipe is arranged between the premixing main pipe and the compressor, and two ends of the connecting pipe are respectively connected to the end of the premixing main pipe and the output end of the compressor, and a first temperature-pressure integrated flowmeter is arranged on the connecting pipe.

[0015] The second pressurizing component includes: a piston cylinder, which is horizontally arranged below the feeding sand cylinder and close to the premixing main pipe, the piston cylinder is connected to the lower end of the feeding sand cylinder, and one end of the piston cylinder is connected to the premixing main pipe; an electric control piston, which is arranged at the other end of the piston cylinder and is used to drive the piston movement in the piston cylinder.

[0016] A plunger booster pump is provided on the liquid adding pipe, and the input end and the output end of the plunger booster pump are respectively connected to the liquid adding pipe. The plunger booster pump is used to pressurize the liquid carbon dioxide so that the liquid carbon dioxide remains in a liquid state and enters the stirring tank. A second temperature-pressure integrated flow meter is provided on the liquid adding pipe near the stirring tank.

[0017] A circulation pipe is arranged between the top of the stirring kettle and the buffer tank, and two ends of the circulation pipe are respectively connected with the stirring kettle and the buffer tank.

[0018] The feeding assembly includes: a first screw feeder, the input port of which is connected to the stirring kettle through a discharge pipe, the discharge pipe is arranged at the lower part of the stirring kettle, and the output port of the first screw feeder is connected to the fracturing main pipe.

[0019] Each feeding sand barrel is connected to a second screw conveyor, an input port of the second screw conveyor is used to input sand particles, and an output port of the second screw conveyor is communicated with the inside of the feeding sand barrel.

[0020] The pressurized liquid carbon dioxide pipeline continuous sand adding device of the present invention has the following advantages:

[0021] First, through the cooperation of the stirring kettle, the buffer tank, the liquid adding pipe, the premixing main pipe, multiple feeding sand cylinders, the first pressurizing component and the multiple second pressurizing components, the gaseous carbon dioxide can be pressurized by the first pressurizing component to convert the gaseous carbon dioxide into high-pressure gaseous carbon dioxide, and the sand particles can be pressurized by each second pressurizing component, so that the sand particles are initially mixed with the high-pressure gaseous carbon dioxide after entering the premixing main pipe and enter the stirring kettle with the high-pressure gaseous carbon dioxide, so that the sand particles are mixed with the liquid carbon dioxide, and the liquid carbon dioxide entering the fracturing well is continuously sanded, which reduces the time required for carbon dioxide dry sand fracturing and improves the work efficiency of carbon dioxide dry sand fracturing.

[0022] Secondly, through the coordination of the premixing main pipe, the stirring kettle and the conveying component, premixing and pressurization can be carried out in the premixing main pipe, main mixing and dispersion can be carried out after entering the stirring kettle, and finally, mixing can be carried out again in the conveying component, thus realizing three-stage mixing of premixing pressurization, main mixing dispersion and conveying feeding, thereby improving the mixing effect of sand particles and liquid carbon dioxide.

[0023] Third, the device can be quickly installed and arranged on site, has simple maintenance and a compact structure, and can meet the requirements of continuous pressurized sand mixing operations, with high mixing concentration, uniform dispersion and a high degree of automation. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0025] Figure 2 It is a schematic diagram of the main structure of the present invention;

[0026] Figure 3 It is a schematic diagram of the top view of the structure of the present invention;

[0027] Figure 4 It is a right view structural schematic diagram of the present invention;

[0028] Figure 5 It is a rear structural schematic diagram of the present invention.

[0029] Reference numerals:

[0030] 1. Mounting frame; 2. Mixing kettle; 3. Connecting pipe; 4. Feeding sand cylinder; 5. First screw conveyor; 6. Electric control piston; 7. Piston cylinder; 8. Premixing main pipe; 9. First temperature-pressure integrated flowmeter; 10. Compressor; 11. Buffer tank; 12. Liquid adding pipe; 13. Plunger booster pump; 14. Second temperature-pressure integrated flowmeter; 15. Pressure relief valve; 16. Circulation pipe; 17. Second screw conveyor; 18. Fracturing main pipe. DETAILED DESCRIPTION

[0031] The technical solution in the present application will be described clearly and in detail below in conjunction with the accompanying drawings. Among them, in the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B: "and / or" in the text is only a description of the association relationship of associated objects, indicating that there can be three relationships, such as A and / or B, which can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, "multiple" refers to two or more than two. The following terms "first" and "second" are used for descriptive purposes only and cannot be understood as implying or suggesting relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0032] like Figure 1As shown, the present invention provides a pressurized liquid carbon dioxide pipeline continuous sand adding device, comprising a mounting frame 1, a fracturing main pipe 18, a stirring kettle 2, a buffer tank 11, a premixing main pipe 8, a plurality of feeding sand cylinders 4, a liquid adding pipe 12, a first pressurizing assembly and a plurality of second pressurizing assemblies, the fracturing main pipe 18 is horizontally arranged in the mounting frame 1, the fracturing main pipe 18 is used to transport liquid carbon dioxide, one end of the fracturing main pipe 18 is connected to a liquid carbon dioxide supply assembly, the liquid carbon dioxide supply assembly is used to supply liquid carbon dioxide to the fracturing main pipe 18, the other end of the fracturing main pipe 18 is used to connect a fracturing well, the stirring kettle 2 and The buffer tanks 11 are respectively arranged in the mounting frame 1, and the conveying front end of the fracturing main pipe 18 is connected to the stirring tank 2 through the liquid adding pipe 12, and the liquid adding pipe 12 is used to deliver part of the liquid carbon dioxide in the fracturing main pipe 18 into the stirring tank 2. The buffer tank 11 is provided with gaseous carbon dioxide, and the stirring tank 2 is connected to the conveying rear end of the fracturing main pipe 18 through the feeding assembly, and the stirring tank 2 is used to mix the sand and the liquid carbon dioxide, and the feeding assembly is used to deliver the mixed sand and the liquid carbon dioxide into the fracturing main pipe 18. The premixing main pipe 8 is horizontally arranged in the mounting frame 1, and one end of the premixing main pipe 8 is connected to the stirring tank 2. The other end of the main pipe 8 is connected to the buffer tank 11, and multiple feeding sand barrels 4 are vertically symmetrically arranged on both sides of the premixing main pipe 8. Each feeding sand barrel 4 is connected to a sand supply component, and the sand is fed into the corresponding feeding sand barrel 4 through the sand supply component. The lower end of each feeding sand barrel 4 is connected to the premixing main pipe 8. The first pressurizing component is used to pressurize the gaseous carbon dioxide to convert the gaseous carbon dioxide into high-pressure gaseous carbon dioxide. The sand in the premixing main pipe 8 is purged by the high-pressure gaseous carbon dioxide, so that the sand enters the stirring tank 2. The multiple second pressurizing components correspond to the multiple feeding sand barrels 4 one by one, and each second pressurizing component Arranged between the corresponding feeding sand cylinder 4 and the premixing main pipe 8, each second pressurizing component is used to pressurize the sand particles, so that after the sand particles enter the premixing main pipe 8, they are preliminarily mixed with the high-pressure gaseous carbon dioxide and enter the mixing tank 2 along with the high-pressure gaseous carbon dioxide. After the sand particles in the mixing tank 2 are mixed with the liquid carbon dioxide, they are transported into the fracturing main pipe 18 under the action of the feeding component and enter the fracturing well along with the liquid carbon dioxide in the fracturing main pipe 18. The liquid carbon dioxide entering the fracturing well is continuously sanded, which reduces the time required for carbon dioxide dry sand fracturing and improves the working efficiency of carbon dioxide dry sand fracturing.

[0033] like Figure 1 , Figure 2 As shown, the first pressurizing component includes a compressor 10, which is arranged between the premixing main pipe 8 and the buffer tank 11. The input end of the compressor 10 is connected to the buffer tank 11, and the output end of the compressor 10 is connected to the other end of the premixing main pipe 8. The gaseous carbon dioxide in the buffer tank 11 is pressurized by the compressor 10 to become high-pressure gas carbon dioxide.

[0034] like Figure 1, Figure 3 As shown, a connecting pipe 3 is provided between the premixing main pipe 8 and the compressor 10, and both ends of the connecting pipe 3 are respectively connected to the end of the premixing main pipe 8 and the output end of the compressor 10, and a first temperature-pressure integrated flowmeter 9 is provided on the connecting pipe 3, and the pressure, temperature and flow of the high-pressure gas carbon dioxide entering the premixing main pipe 8 are detected by the first temperature-pressure integrated flowmeter 9.

[0035] like Figure 1 , Figure 2 As shown, the second pressurizing component includes a piston cylinder 7 and an electric-controlled piston 6. The piston cylinder 7 is horizontally arranged below the feeding sand cylinder 4. The position of the piston cylinder 7 is close to the premixing main pipe 8. The piston cylinder 7 is connected to the lower end of the feeding sand cylinder 4. The piston cylinder 7 is communicated with the feeding sand cylinder 4. One end of the piston cylinder 7 is connected to the premixing main pipe 8, that is, the piston cylinder 7 is communicated with the premixing main pipe 8. The electric-controlled piston 6 is arranged at the other end of the piston cylinder 7. The electric-controlled piston 6 is used to drive the piston in the piston cylinder 7 to move, so that the pressure inside the piston cylinder 7 increases, so as to pressurize the sand particles entering the premixing main pipe 8.

[0036] like Figure 1 , Figure 2 , Figure 5 As shown, a plunger booster pump 13 is provided on the liquid adding pipe 12, and the input end and the output end of the plunger booster pump 13 are respectively connected to the liquid adding pipe 12, and the plunger booster pump 13 is used to pressurize the liquid carbon dioxide so that the liquid carbon dioxide remains in a liquid state and enters the stirring tank 2, that is, the liquid adding pipe 12 is divided into two parts, consisting of a first liquid adding branch pipe and a second liquid adding branch pipe, the first liquid adding branch pipe is arranged between the plunger booster pump 13 and the fracturing main pipe 18, and the two ends of the first liquid adding branch pipe are respectively connected to the fracturing main pipe 18 and the input end of the plunger booster pump 13, the second liquid adding branch pipe is arranged between the plunger booster pump 13 and the stirring tank 2, and the two ends of the second liquid adding branch pipe are respectively connected to the output end of the plunger booster pump 13 and the stirring tank 2, and a second temperature-pressure integrated flowmeter 14 is arranged on the liquid adding pipe 12 near the stirring tank 2, and the pressure, temperature and flow of the liquid carbon dioxide entering the stirring tank 2 are detected by the second temperature-pressure integrated flowmeter 14.

[0037] like Figure 3 , Figure 4 As shown, a circulation pipe 16 is provided between the top of the stirring tank 2 and the buffer tank 11, and both ends of the circulation pipe 16 are respectively connected to the stirring tank 2 and the buffer tank 11. The gaseous carbon dioxide entering the stirring tank 2 is passed through the circulation pipe 16 connected to the top of the stirring tank 2 and enters the buffer tank 11 for recycling.

[0038] like Figure 1 , Figure 5As shown, the feeding assembly includes a first screw conveyor 17, the input port of the first screw conveyor 17 is connected to the mixing tank 2 through a discharge pipe, the discharge pipe is arranged at the lower part of the mixing tank 2, and the output port of the first screw conveyor 17 is connected to the fracturing main pipe 18. The gravity inlet and the boost outlet principle are used to overcome the pressure change in the mixing tank, so that the mixed liquid carbon dioxide and sand particles can enter the first screw conveyor 17 through the discharge pipe, and are transported into the fracturing main pipe 18 through the first screw conveyor 17.

[0039] like Figure 1 , Figure 2 As shown, the upper part of each feeding sand barrel 4 is a closed structure, and each feeding sand barrel 4 is funnel-shaped. The upper part of each feeding sand barrel 4 is connected to a second screw conveyor 17, and the input port of the second screw conveyor 17 is used to input sand particles, and the input port of the second screw conveyor 17 is connected to a sand particle supply assembly, and the output port of the second screw conveyor 17 is connected to the inside of the feeding sand barrel 4. The sand particles can be continuously transported into the feeding sand barrel 4 through the second screw conveyor 17, and the flow rate entering the feeding sand barrel 4 can also be adjusted through the second screw conveyor 17. The number of the feeding sand barrels 4 is preferably four, and the four feeding sand barrels 4 are respectively vertically arranged on both sides of the premixing main pipe 8 in pairs, and the sand particles are alternately transported to the premixing main pipe 8 through the four feeding sand barrels 4.

[0040] Among them, a stirring component is arranged in the stirring kettle 2, and the stirring component includes a stirring motor, a stirring shaft and multiple stirring blades. The stirring motor is arranged at the top of the stirring kettle 2, and the stirring shaft is vertically arranged in the stirring kettle 2. The upper end of the stirring shaft passes through the top of the stirring kettle 2 and is connected to the output end of the stirring motor. Multiple stirring blades are arranged on the stirring shaft. The stirring motor drives the stirring shaft to rotate, and the stirring shaft drives the multiple stirring blades to rotate, so as to stir the liquid carbon dioxide and sand particles entering the stirring kettle 2.

[0041] Among them, a heat exchange interlayer is arranged inside the side wall of the stirring tank 2, and a cooling circulation component is arranged inside the heat exchange interlayer. The cooling circulation component is used to perform low-temperature circulation refrigeration of the cold medium to reduce the internal temperature of the stirring tank 2 and reduce the gasification of liquid carbon dioxide.

[0042] like Figure 1 , Figure 3 , Figure 4 As shown, a pressure relief valve 15 is arranged on the top of the stirring tank 2 , and an electric-controlled air release pipeline and a temperature and pressure tester are arranged on the pressure relief valve 15 to control the opening and closing of the pressure relief valve 15 .

[0043] Working principle: When in use, the four second screw conveyors 17, the electric control piston 6, the compressor 10, the plunger booster pump 13, the stirring motor and the first screw conveyor 17 are started, so that the four feeding sand barrels 4 alternately convey sand to the premixing main pipe 8. The electric control piston 6 at the bottom of each feeding sand barrel 4 is started, driving the piston in the piston cylinder 7 to move, so that the pressure inside the piston cylinder 7 increases, pressurizing the sand entering the premixing main pipe 8, increasing the pressure in the premixing main pipe 8, and at the same time, the gaseous carbon dioxide in the buffer tank 11 of the compressor 10 is pressurized to become high-pressure gas carbon dioxide that enters the premixing main pipe 8, and the sand in the premixing main pipe 8 is pressed. The mixing tank 2 is purged to allow the sand particles to enter the mixing tank 2 along with the high-pressure gaseous carbon dioxide. At the same time, the plunger booster pump 13 pressurizes the liquid carbon dioxide diverted from the fracturing main pipe 18 to keep it in liquid form and transport it into the mixing tank 2. The stirring motor drives a plurality of stirring blades to rotate through the stirring shaft to stir the liquid carbon dioxide and the sand particles. After the mixture is evenly mixed, the mixture enters the first screw conveyor 17 through the suction pipe at the bottom. The mixed liquid carbon dioxide and sand particles are transported into the fracturing main pipe 18 through the first screw conveyor 17. The liquid carbon dioxide in the fracturing main pipe 18 enters the fracturing well to perform carbon dioxide dry fracturing with sand.

[0044] It is to be understood that the present invention is described by some embodiments, and it is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.

Claims

1. A device for continuously adding sand to a pressurized liquid carbon dioxide pipeline, comprising a fracturing main pipe (18), a stirring tank (2) and a buffer tank (11), wherein the fracturing main pipe (18) is used to transport liquid carbon dioxide, the front end of the fracturing main pipe (18) is connected to the stirring tank (2) via a liquid adding pipe (12), the liquid adding pipe (12) is used to send part of the liquid carbon dioxide in the fracturing main pipe (18) into the stirring tank (2), the buffer tank (11) stores gaseous carbon dioxide, the stirring tank (2) and the rear end of the fracturing main pipe (18) are connected via a material feeding component, the material feeding component is used to feed the mixed sand particles and liquid carbon dioxide into the fracturing main pipe (18), characterized in that: Also includes: The two ends of the premixing main pipe (8) are respectively connected to the stirring tank (2) and the buffer tank (11); A plurality of feeding sand cylinders (4) are vertically symmetrically arranged on both sides of the premixing main pipe (8), and the lower end of each feeding sand cylinder (4) is connected to the premixing main pipe (8); A first pressurizing component is disposed between the premixing main pipe (8) and the buffer tank (11) and is used to pressurize the gaseous carbon dioxide to convert the gaseous carbon dioxide into high-pressure gaseous carbon dioxide; A plurality of second pressurizing components correspond one to one with the plurality of feeding sand barrels (4), each second pressurizing component is arranged between the corresponding feeding sand barrel (4) and the premixing main pipe (8), and each second pressurizing component is used to pressurize the sand particles so that the sand particles are initially mixed with the high-pressure gaseous carbon dioxide after entering the premixing main pipe (8) and enter the stirring kettle (2) along with the high-pressure gaseous carbon dioxide.

2. The pressurized liquid carbon dioxide pipeline continuous sand adding device according to claim 1, characterized in that: The first pressurizing component comprises: a compressor (10) arranged between the premixing main pipe (8) and the buffer tank (11), the input end of the compressor (10) being connected to the buffer tank (11), and the output end of the compressor (10) being connected to the other end of the premixing main pipe (8).

3. The continuous sand adding device for pressurized liquid carbon dioxide pipeline according to claim 2 is characterized in that: A connecting pipe (3) is provided between the premixing main pipe (8) and the compressor (10), and two ends of the connecting pipe (3) are respectively connected to the end of the premixing main pipe (8) and the output end of the compressor (10), and a first temperature-pressure integrated flow meter (9) is provided on the connecting pipe (3).

4. The continuous sand adding device for pressurized liquid carbon dioxide pipeline according to claim 1, characterized in that: The second pressurizing assembly comprises: a piston cylinder (7) horizontally arranged below the feeding sand cylinder (4) and located close to the premixing main pipe (8), the piston cylinder (7) being connected to the lower end of the feeding sand cylinder (4), and one end of the piston cylinder (7) being connected to the premixing main pipe (8); and an electric control piston (6) arranged at the other end of the piston cylinder (7), the electric control piston (6) being used to drive the piston in the piston cylinder (7) to move.

5. The pressurized liquid carbon dioxide pipeline continuous sand adding device according to claim 1, characterized in that: The liquid adding pipe (12) is provided with a plunger booster pump (13), the input end and the output end of the plunger booster pump (13) are respectively connected to the liquid adding pipe (12), the plunger booster pump (13) is used to pressurize the liquid carbon dioxide so that the liquid carbon dioxide remains in a liquid state and enters the stirring tank (2), and the liquid adding pipe (12) is provided with a second temperature-pressure integrated flow meter (14) at a position close to the stirring tank (2).

6. The pressurized liquid carbon dioxide pipeline continuous sand adding device according to claim 1, characterized in that: A circulation pipe (16) is provided between the top of the stirring tank (2) and the buffer tank (11), and both ends of the circulation pipe (16) are respectively connected to the stirring tank (2) and the buffer tank (11).

7. The pressurized liquid carbon dioxide pipeline continuous sand adding device according to claim 1, characterized in that: The feeding assembly comprises: a first screw feeder (17), the input port of which is connected to the stirring tank (2) via a discharge pipe, the discharge pipe being arranged at the lower part of the stirring tank (2), and the output port of the first screw feeder (17) being connected to the fracturing main pipe (18).

8. The pressurized liquid carbon dioxide pipeline continuous sand adding device according to claim 1, characterized in that: Each of the feeding sand barrels (4) is connected to a second screw conveyor (17), the input port of the second screw conveyor (17) is used to input sand particles, and the output port of the second screw conveyor (17) is connected to the inside of the feeding sand barrel (4).

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