Carbon dioxide pre-frac energizing fracturing apparatus

Abstract

The application discloses a carbon dioxide prepositioned energy-increasing fracturing equipment, which comprises a liquid carbon dioxide pumping group, a buffer tank, a booster manifold, a backflow manifold, a carbon dioxide separation device, a fracturing fluid pumping group, a sand mixing vehicle and a pump vehicle; a plurality of tank bodies in the liquid carbon dioxide pumping group are communicated with the buffer tank through an integrated manifold; the buffer tank is communicated with a liquid inlet end of the carbon dioxide separation device through the booster manifold; a liquid outlet end of the carbon dioxide separation device is communicated with the pump vehicle, and a gas outlet end of the carbon dioxide separation device is communicated with the buffer tank through the backflow manifold; a plurality of tank bodies in the fracturing fluid pumping group are communicated with the sand mixing vehicle through an integrated manifold, and the sand mixing vehicle is connected to connecting pipelines of the carbon dioxide separation device and the pump vehicle through a pipeline; the equipment can effectively separate gaseous carbon dioxide and dry ice from liquid carbon dioxide before the liquid carbon dioxide enters the pump vehicle, ensures normal operation of the pump vehicle and pipelines along a line, improves operation efficiency of carbon dioxide energy-increasing fracturing of an oil field and shortens operation time.

Description

Technical Field

[0001] This invention relates to the field of equipment technology for downhole operations in oil and gas fields, and in particular to a carbon dioxide pre-energized fracturing device. Background Technology

[0002] With the increasing demand for oil and gas in my country, unconventional oil and gas resources such as tight oil and gas have become strategic replacement targets for increasing reserves and production. Due to the extremely low permeability and underdeveloped pores in tight oil and gas reservoirs, fracturing is generally required to achieve industrial production capacity. The rotation of the fracturing fluid is a key factor affecting the successful development of tight oil and gas reservoirs. In tight formations, due to the extremely low permeability and small pore throats, water molecules may enter the tiny pore throats in the matrix during fracturing, forming liquid-phase traps and increasing the resistance to oil and gas flow. Capillary forces can also damage the relative permeability of the gas, adversely affecting production capacity.

[0003] Carbon dioxide possesses unique physical properties; it is a relatively inert compound, and its gas, liquid, and solid phases can interconvert during fracturing. Due to its unique physical and thermodynamic properties, and its ability to effectively meet the performance and operational requirements of fracturing fluids, liquid carbon dioxide fracturing has become an effective method for developing low-permeability tight oil and gas. During field operations, carbon dioxide can be injected into the wellbore in a liquid state below the critical temperature. Upon entering the perforation, the liquid carbon dioxide expands, changing from a liquid to a gaseous state. After fracturing, the carbon dioxide is returned in gaseous form, thus causing no damage to the formation facies, and the effect of capillary forces is negligible. Liquid carbon dioxide fracturing technology has the natural advantage of being non-damaging; after injection into the formation, it can increase formation energy, providing driving force for oil and gas flow. Carbon dioxide pre-storage volumetric fracturing has become an effective reservoir stimulation measure. However, in carbon dioxide-enhanced fracturing operations, the presence of gaseous carbon dioxide slugs in the pipeline and pump truck can cause the pump truck to stop, leading to the interruption of the carbon dioxide-enhanced fracturing operation and its inability to continue. If liquid carbon dioxide solidifies into dry ice, it can clog pipelines or valves, causing interruptions to enhanced fracturing operations. Conventional ground equipment struggles to prevent this from happening during enhanced fracturing operations, thus reducing operational efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a carbon dioxide pre-energized fracturing device that ensures the smooth pumping of carbon dioxide and fracturing fluid by pump trucks and pipelines along the pipeline.

[0005] Therefore, the technical solution of the present invention is as follows:

[0006] A carbon dioxide pre-empowered fracturing device includes a liquid carbon dioxide pumping unit, a buffer tank, a booster manifold, a reflux manifold, a carbon dioxide separator, a fracturing fluid pumping unit, a sand mixing truck, and a pump truck; wherein...

[0007] The liquid carbon dioxide pumping unit consists of at least two liquid carbon dioxide pumping devices arranged in parallel; the outlet end of each liquid carbon dioxide pumping device is connected to the inlet end of the first integrated manifold through a first delivery pipe, and the outlet end of the first integrated manifold is connected to the inlet end of the buffer tank through a second delivery pipe; an opening and closing control valve is provided on each first delivery pipe and the second delivery pipe.

[0008] The booster manifold consists of a third delivery pipe, a first booster pump installed on the third delivery pipe, and an on / off control valve; one end of the third delivery pipe is connected to the liquid outlet on the side wall of the buffer tank; the reflux manifold consists of a reflux pipe and a one-way valve installed on the reflux pipe; one end of the reflux pipe is connected to the reflux port at the top of the buffer tank; the one-way valve ensures that the material in the pipe can only flow back into the buffer tank;

[0009] The carbon dioxide separation equipment includes a motor, a separation tank, and a storage tank. The separation tank includes a separation tank, a rotating shaft, a spiral blade assembly, a conical baffle, and stirring blades. A liquid inlet is located on the top side wall of the separation tank, which connects to the other end of a third conveying pipe. The rotating shaft is a shaft with an axial channel in its center, vertically positioned and centered inside the upper part of the separation tank, with its top end extending outwards through an opening at the top of the separation tank. The rotating shaft is rotatably fixed to the wall of the opening in the separation tank via a rotating bearing, with its top opening serving as the outlet and connecting to the other end of a return pipe, and its bottom opening serving as the inlet. The spiral blade assembly consists of multiple spiral blades evenly distributed and fixed on the outer wall of the rotating shaft along the circumference. The conical baffle is a cone-shaped baffle centered inside the separation tank, with its outer diameter gradually increasing from top to bottom. The separator has a cylindrical tube with multiple through holes evenly distributed on its surface and multiple vertically pointing spikes evenly distributed on its outer surface. A conical baffle is fixed below the rotating shaft at intervals by multiple steel rods evenly distributed circumferentially and vertically arranged. The maximum outer diameter of the conical baffle is the same as the inner diameter of the separator. A connecting cylinder is vertically fixed on the inner surface of the conical baffle. The stirring blades are a stirring structure composed of multiple inverted L-shaped blades arranged inverted circumferentially and fixed at the bottom of the connecting cylinder. The motor is set on one side of the separator with its output shaft vertically pointing upward. It forms a belt drive with the rotating shaft through a transmission belt. The storage tank is set on the other side of the separator. Its top side wall has a storage tank inlet connected to the liquid outlet of the separator through a gas supply pipe. Its bottom has a storage tank outlet connected to the liquid inlet of the pump truck through a fourth delivery pipe.

[0010] The fracturing fluid pumping unit consists of at least two fracturing fluid storage tanks. The outlet of each fracturing fluid storage tank is connected to the inlet of the second integrated manifold through a fifth delivery pipe, and each fifth delivery pipe is equipped with an on / off control valve. The outlet of the second integrated manifold is connected to the inlet of the sand mixing truck. The outlet of the sand mixing truck is connected to the fourth delivery pipe through a seventh delivery pipe. The pump truck pumps liquid carbon dioxide or fracturing fluid into the wellhead.

[0011] Furthermore, the liquid carbon dioxide storage tank is a horizontal tank composed of a protective layer, an insulation layer, and an anti-corrosion layer sequentially fitted from the outside in.

[0012] Furthermore, each liquid carbon dioxide pumping device includes a liquid carbon dioxide storage tank, a second booster pump, a cooling pump, a first pressure gauge, a thermometer, and a first ultrasonic liquid level monitor; the second booster pump and the cooling pump are respectively connected to the inner cavity of the liquid carbon dioxide storage tank through pipelines to maintain the liquid carbon dioxide in the tank at a preset pressure and temperature; the first pressure gauge and the thermometer are installed at the top of the liquid carbon dioxide storage tank to collect the real-time pressure and real-time temperature of the inner cavity of the tank; the first ultrasonic liquid level monitor is installed at the bottom of the liquid carbon dioxide storage tank to monitor the liquid level height of the liquid carbon dioxide in the tank.

[0013] Furthermore, both the first and second integrated manifolds consist of a pipe body and two supports; the pipe body is a cylindrical pipe body with manifold outlets at both ends, and multiple manifold inlets arranged in a straight line are evenly distributed on its side wall, with a cover provided at each manifold inlet; the pipe body is horizontally fixed on the top surface of the two supports, which are spaced apart and fixed to the ground.

[0014] Furthermore, a second pressure gauge is installed at the top of the buffer tank to collect the pressure inside the buffer tank; an ultrasonic liquid level monitor is installed at the bottom of the buffer tank to monitor the liquid carbon dioxide level inside the tank.

[0015] Furthermore, a third ultrasonic liquid level monitor is installed on the bottom side wall of the storage tank to monitor the liquid level inside the tank.

[0016] Furthermore, in the conical septum, the diameter of the through hole is 3~8mm; the spike is a conical spike with a height of 2~6mm.

[0017] Compared with existing technologies, this carbon dioxide pre-empowered fracturing equipment can effectively separate gaseous carbon dioxide and dry ice from liquid carbon dioxide before it enters the pump truck, ensuring the normal operation of the pump truck and pipelines along the pipeline, improving the efficiency of carbon dioxide-enhanced fracturing in oil fields, and shortening the operation time. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the carbon dioxide pre-energized fracturing device of the present invention;

[0019] Figure 2 This is a schematic diagram of the integrated manifold structure of the carbon dioxide pre-energized fracturing equipment of the present invention;

[0020] Figure 3 This is a schematic diagram of the carbon dioxide separation device in the carbon dioxide pre-energized fracturing equipment of the present invention. Detailed Implementation

[0021] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to those skilled in the art that embodiments of the invention may be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid confusion with embodiments of the invention.

[0022] To fully understand the embodiments of the present invention, detailed structures will be presented in the following description. Obviously, the implementation of the embodiments of the present invention is not limited to the specific details familiar to those skilled in the art. Preferred embodiments of the present invention are described in detail below; however, in addition to these detailed descriptions, the present invention may have other embodiments. In the description of the present invention, terms such as "inner side," "outer side," "longitudinal," "transverse," "upper," "lower," "top," and "bottom," indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and not as requiring the present invention to be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the present invention.

[0023] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings:

[0024] See Figure 1 The carbon dioxide pre-energized fracturing equipment includes a liquid carbon dioxide pumping unit, an integrated manifold unit, a buffer tank 3, a booster manifold, a reflux manifold, a carbon dioxide separation unit 5, a fracturing fluid pumping unit, a sand mixing truck 9, and a pump truck 10.

[0025] The liquid carbon dioxide pumping unit consists of two parallel liquid carbon dioxide pumping devices to ensure the supply of liquid carbon dioxide during the pumping process; each liquid carbon dioxide pumping device includes a liquid carbon dioxide storage tank 1, a second booster pump 11, a cooling pump 12, a first pressure gauge 13, a thermometer 14, and a first ultrasonic liquid level monitor 15; specifically,

[0026] Liquid carbon dioxide storage tank 1 is used to store liquid carbon dioxide. Its tank body is a horizontal tank composed of a protective layer, an insulation layer, and a corrosion-resistant layer, sequentially fitted from the outside in. The internal volume of the tank is 50~80m³. 3 Preferably, the protective layer of the tank is made of carbon steel (such as Q235-B type carbon steel), the anti-corrosion layer is made of temperature and pressure resistant material (such as 16MnDR), and the heat insulation layer is formed by filling the annular cavity between the protective layer and the anti-corrosion layer with hot perlite and then drawing a vacuum.

[0027] The second booster pump 11 and the cooling pump 12 are located on the adjacent side of the liquid carbon dioxide storage tank 1 and are respectively connected to the bottom of the inner cavity of the liquid carbon dioxide storage tank 1 so that the liquid carbon dioxide stored in the inner cavity of the tank can be maintained within a certain pressure and temperature range; specifically, the second booster pump 11 and the cooling pump 12 should be able to ensure that the pressure of the liquid carbon dioxide in the tank is ≥2.5Mpa and the temperature is ≤-15℃.

[0028] The first pressure gauge 13 and thermometer 14 are installed on the top of the liquid carbon dioxide storage tank 1, and their detection ends are located at the top of the inner cavity of the tank to collect the real-time pressure and real-time temperature of the inner cavity of the tank, thereby monitoring whether the pressure inside the carbon dioxide storage tank 1 is lower than the pressure critical value and whether the temperature is lower than the temperature critical value.

[0029] The first ultrasonic liquid level monitor 15 is installed at the bottom of the liquid carbon dioxide storage tank 1, and its detection end is located at the critical height of the liquid level warning at the bottom of the inner cavity of the tank, so that when the liquid carbon dioxide level in the tank is lower than the critical liquid level, the first ultrasonic liquid level monitor 15 will detect it and issue an alarm.

[0030] The integrated manifold assembly consists of a first integrated manifold and a second integrated manifold (b); see also Figure 2 The integrated manifold consists of a pipe body 201 and two supports 202. The two supports 202 are identical triangular supports, which are fixed to the ground at intervals. The pipe body 201 is a cylindrical pipe with manifold outlets 204 at both ends, and multiple manifold inlets 203 are evenly distributed on its side wall in a straight line. The pipe body 201 is fixed to the top surface of the two supports 202 in a horizontal manner, and the manifold outlets 204 and each manifold inlet 203 on the pipe body 201 are at the same height as the liquid outlet end on the liquid carbon dioxide storage tank 1. Each manifold inlet 203 is provided with a cover. When in use, the manifold inlets 203 that are not connected to an external pipeline are closed by the cover.

[0031] The two manifold inlets 203 on the first integrated manifold are connected to the liquid outlets of the two liquid carbon dioxide storage tanks 1 through two first delivery pipes and form a connection. Each first delivery pipe is equipped with an opening and closing control valve to control the opening and closing state of the first delivery pipe.

[0032] Buffer tank 3 is used for temporary storage and pressure buffering of liquid carbon dioxide; specifically, it is a container with an internal volume of 50~200 m³. 3The tank body has an inlet and an outlet on the opposite side, and a reflux port on the top. The inlet of the buffer tank 3 is connected to the two manifold outlets 204 on the first integrated manifold through the second delivery pipe, and each second delivery pipe is equipped with an opening and closing control valve to control the opening and closing state of the second delivery pipe. The second delivery pipe consists of two branch pipes connected to one end of the main pipe. One end of the main pipe is connected to the inlet of the buffer tank 3, and the two ends of the branch pipes are respectively connected to the two manifold outlets 204 on the first integrated manifold.

[0033] A second pressure gauge 16 is installed on the top of the buffer tank 3. The probe of the second pressure gauge 16 is located at the top of the inner cavity of the tank to collect the real-time pressure of the inner cavity of the buffer tank 3, and then monitor whether the pressure in the buffer tank 3 is lower than the pressure critical value. An ultrasonic liquid level monitor 17 is installed at the bottom of the buffer tank 3. The probe of the ultrasonic liquid level monitor 17 is located at the liquid level warning critical height at the bottom of the inner cavity of the tank, so that when the liquid carbon dioxide level in the tank is lower than the critical liquid level, the ultrasonic liquid level monitor 17 will detect it and issue an alarm.

[0034] The booster manifold consists of a third delivery pipe, a first booster pump 4, and an on / off control valve. One end of the third delivery pipe is connected to the outlet of the buffer tank 3, and the other end is connected to the carbon dioxide separator 5. The first booster pump 4 is installed on the third delivery pipe to maintain the pressure in the pipe. The on / off control valve is installed on the third delivery pipe to control the opening and closing state of the third delivery pipe. As a preferred embodiment, the first booster pump 4 is installed near the outlet of the buffer tank 3, and the on / off control valve is installed near the inlet 5031 of the carbon dioxide separator 5.

[0035] The reflux manifold consists of a reflux pipe and a one-way valve 7; one end of the reflux pipe is connected to the reflux port of the buffer tank 3 and forms a connection, and the other end is connected to the carbon dioxide separator 5; the one-way valve 7 is installed on the reflux pipe and allows the gas-liquid mixture in the reflux pipe to flow only from the carbon dioxide separator 5 to the buffer tank 3.

[0036] See Figure 3 The carbon dioxide separation device 5 includes a motor 501, a separation tank, and a storage tank 502;

[0037] The separation tank includes a separation tank 503, a rotating shaft 504, a spiral blade assembly 505, a conical baffle 506, and stirring blades 507; specifically,

[0038] The top side wall of the separator 503 is provided with a separator inlet 5031 and the bottom is provided with a separator outlet 5032; the separator inlet 5031 is connected to the other end of the third conveying pipe and forms a communication.

[0039] The rotating shaft 504 is a shaft with an axial channel in the center. Its top opening serves as the air outlet and is connected to the other end of the return pipe through a rotary sealing joint to form a communication. Its bottom opening serves as the air inlet 5041. The rotating shaft 504 is vertically and centrally located on the upper side inside the separator 503, and the top of the rotating shaft 504 is located on the outside of the separator 503 through an opening in the top of the separator 503. The rotating shaft 504 is rotatably fixed at the opening of the separator 503 through a rotary bearing, and a sealing element is provided between the rotating shaft 504, the rotating shaft, and the wall of the opening to make the inner cavity of the separator 503 a closed chamber.

[0040] The spiral blade assembly 505 consists of four spiral blades, which are evenly distributed and fixed along the circumferential direction on the outer wall of the rotating shaft 504 located inside the separation tank 503.

[0041] The conical partition 506 is a conical cylinder with multiple through holes 5061 evenly distributed on it, and multiple vertically upward spikes 5062 evenly distributed on its outer surface; preferably, the diameter of the through holes 5061 is 3~8mm; the spikes 5062 are conical spikes with a height of 2~6mm; the conical partition 506 is centrally located below the rotating shaft 504 in the separation tank 503 with its outer diameter gradually increasing from top to bottom, and is connected to the bottom of the rotating shaft 504 by four steel rods 508 evenly distributed circumferentially and vertically arranged; specifically, the top end of the steel rod 508 is on the bottom end face of the rotating shaft 504, and the bottom end is fixed on the outer surface of the conical partition 506;

[0042] The maximum outer diameter of the conical partition 506 is the same as the inner diameter of the separator 503, so as to divide the inner cavity of the separator 503 into an upper chamber and a lower chamber. The conical partition 506 is used to block the blocky dry ice from moving downward and prevent blockage of the outlet. At the same time, the dry ice particles remaining in the upper chamber are decomposed into liquid carbon dioxide or gaseous carbon dioxide under the rotational cutting action of the spiral blade assembly 505 and the impact and crushing action of the spikes 5062. The gaseous carbon dioxide flows back to the buffer tank 3 from the air inlet 5041, while the liquid carbon dioxide flows into the lower chamber through the through hole 5061.

[0043] The top of the connecting cylinder 509 is vertically fixed to the inner surface of the conical partition 506; the stirring blade 507 is composed of four L-shaped blades, which are inverted and fixed to the bottom end face of the connecting cylinder 509 in the circumferential direction to form a stirring structure.

[0044] The motor 501 is installed on the left side of the separator 503 with its output shaft facing vertically upward; the output shaft end of the motor 501 and the top end of the rotating shaft 504 are fitted with belts, so that the output shaft of the motor 501 and the rotating shaft 504 are connected by a belt drive.

[0045] The storage tank 502 is arranged side-by-side on the right side of the separator 503, and it has an internal cavity volume of 20m³. 3 The vertical tank body has a liquid storage tank 502 with a liquid storage tank inlet 5021 on the top side wall and a liquid storage tank outlet 5022 at the bottom. The liquid storage tank inlet 5021 is connected to the outlet 5032 of the separator tank through a gas transmission pipe. The liquid storage tank outlet 5022 is connected to the liquid inlet of the pump truck 10 through a fourth transmission pipe. A third ultrasonic liquid level monitor 18 is installed on the bottom side wall of the liquid storage tank 502. The detection end of the third ultrasonic liquid level monitor 18 is located at the liquid level warning critical height at the bottom of the inner cavity of the tank to monitor the liquid carbon dioxide level in the liquid storage tank 502. When the liquid level in the liquid storage tank 502 is low, the power of the pump truck 10 is reduced to keep the liquid level within the normal range, thereby ensuring the normal pumping operation of the pump truck 10.

[0046] The fracturing fluid pumping unit consists of two fracturing fluid storage tanks 8. Two manifold inlets 203 on the second integrated manifold are connected to the liquid outlets of the two fracturing fluid storage tanks 8 via two fifth delivery pipes, forming a communication. Each fifth delivery pipe is equipped with an opening / closing control valve to control its opening / closing state. Two manifold outlets 204 on the second integrated manifold are connected to the inlet of the sand mixing truck 9 via a sixth delivery pipe. The sixth delivery pipe consists of two branch pipes connected to one end of the main pipe. One end of the main pipe is connected to the inlet of the sand mixing truck 9, and the two ends of the branch pipes are connected to the two manifold outlets 204 on the second integrated manifold. The outlet of the sand mixing truck 9 is connected to the fourth delivery pipe via a seventh delivery pipe, allowing the pump truck 10 to pump liquid carbon dioxide or fracturing fluid to the wellhead 19. An opening / closing control valve is installed on the seventh delivery pipe.

[0047] The specific working process of this carbon dioxide pre-energized fracturing equipment is as follows:

[0048] Liquid carbon dioxide from multiple carbon dioxide storage tanks 1 is collected in buffer tank 3 via a first integrated pipe. A first booster pump 4 delivers the liquid carbon dioxide from buffer tank 3 to separation tank 503. Motor 501 starts and drives shaft 504 to rotate at 50-300 r / min, which in turn drives the spiral blade assembly 505, conical baffle 506, and stirring blade 507 to rotate at high speed, agitating the liquid carbon dioxide in separation tank 503 and generating strong centrifugal force. If gaseous carbon dioxide is present inside the liquid carbon dioxide, it will move towards the center of separation tank 503 under the influence of centrifugal force and flow towards the inlet end 5041, then flow back along the return path... The flow pipe 6 returns to the buffer tank 3 via the one-way valve 7; if there is blocky dry ice inside the liquid carbon dioxide, the dry ice will move towards the center of the separator 503 under the action of centrifugal force. During the process of moving towards the center, the dry ice will encounter the spikes 5062 on the conical partition 506. Under the action of the spikes 5062, the dry ice will be crushed and begin to move towards the low-pressure area of ​​the inlet end 5041. Under different pressures, the dry ice will be transformed into liquid carbon dioxide or gaseous carbon dioxide; the liquid carbon dioxide separated from the separator enters the storage tank 502 through the pipeline and is then transported to the pump truck 10; the pump truck 10 starts to work, using a construction pump pressure of 8~10Mpa and a flow rate of 0.8~1m 3 A flow rate of / min allows liquid carbon dioxide to enter the wellbore and formation through wellhead 19; this process is the liquid carbon dioxide pumping stage. After the liquid carbon dioxide pumping stage is completed, the liquid carbon dioxide pumping pipeline is shut off, and 400~1000m³ of fracturing fluid is added to the fracturing fluid storage tank 8. 3 The fracturing fluid flows into the sand mixing truck 9 through the second integrated manifold, and the pump truck 10 starts working again, using a construction pump pressure of 60~70MPa and 8~9m 3 The fracturing fluid is discharged at a rate of / min, allowing it to enter the wellbore and formation through wellhead 19; at this point, the entire carbon dioxide-enhanced fracturing process is complete.

[0049] In summary, the content of this invention is not limited to the above-described embodiments. Those skilled in the art can propose other embodiments within the technical guiding principles of this invention, but these embodiments are all included within the scope of this invention.

Claims

1. A carbon dioxide pre-energized fracturing device, characterized in that, This includes a liquid carbon dioxide pumping unit, a buffer tank (3), a booster manifold, a return manifold, a carbon dioxide separation unit (5), a fracturing fluid pumping unit, a sand mixing truck (9), and a pump truck (10); among which, The liquid carbon dioxide pumping unit consists of at least two parallel liquid carbon dioxide pumping devices; the outlet of each liquid carbon dioxide pumping device is connected to the inlet of the first integrated manifold through a first delivery pipe, and the outlet of the first integrated manifold is connected to the inlet of the buffer tank (3) through a second delivery pipe; an opening and closing control valve is provided on each first delivery pipe and the second delivery pipe. The booster manifold consists of a third delivery pipe, a first booster pump (4) installed on the third delivery pipe, and an on / off control valve; one end of the third delivery pipe is connected to the liquid outlet on the side wall of the buffer tank (3); the return manifold consists of a return pipe and a one-way valve (7) installed on the return pipe; one end of the return pipe is connected to the return port at the top of the buffer tank (3); the one-way valve (7) ensures that the material in the pipe can only return to the buffer tank (3); The carbon dioxide separation device (5) includes a motor (501), a separation tank, and a storage tank (502); the separation tank includes a separation tank (503), a rotating shaft (504), a spiral blade assembly (505), a conical baffle (506), and stirring blades (507); the top side wall of the separation tank (503) is provided with a separation tank inlet (5031), which is connected to the other end of the third conveying pipe; the rotating shaft (504) is a shaft with an axial channel in the center, which is vertically and centrally located inside the upper side of the separation tank (503). The top of the shaft extends out through the top opening of the separator (503) to the outside of the separator (503); the shaft (504) is rotatably fixed to the wall of the opening of the separator (503) by a rotating bearing, with its top opening serving as the outlet end connected to the other end of the return pipe, and its bottom opening serving as the inlet end (5041); the spiral blade assembly (505) consists of multiple spiral blades evenly distributed and fixed on the outer wall of the shaft (504) along the circumferential direction; the conical partition (506) is a spacer whose outer diameter gradually increases from top to bottom. A conical cylinder is set inside the separator (503), with multiple through holes (5061) evenly distributed on it, and multiple vertically pointing spikes (5062) evenly distributed on its outer surface; a conical partition (506) is fixed below the rotating shaft (504) by multiple steel rods (508) evenly distributed around the circumference and vertically arranged; the maximum outer diameter of the conical partition (506) is the same as the inner diameter of the separator (503); a connecting cylinder (509) is vertically fixed on the inner surface of the conical partition (506), and stirring blades (506) are used. 07) Set at the bottom of the connecting cylinder (509); the motor (501) is set on one side of the separator (503) with its output shaft facing vertically upward, and it forms a belt drive with the rotating shaft (504) through the transmission belt; the storage tank (502) is set on the other side of the separator (503), and its top side wall is provided with a storage tank inlet (5021) connected to the separator outlet (5032) through the gas transmission pipe, and its bottom is provided with a storage tank outlet (5022) connected to the pump truck (10) through the fourth transmission pipe. The fracturing fluid pumping unit consists of at least two fracturing fluid storage tanks (8). The outlet of each fracturing fluid storage tank (8) is connected to the inlet of the second integrated manifold through the fifth delivery pipe, and each fifth delivery pipe is equipped with an opening and closing control valve. The outlet of the second integrated manifold is connected to the inlet of the sand mixing truck (9). The outlet of the sand mixing truck (9) is connected to the fourth delivery pipe through the seventh delivery pipe. The pump truck (10) pumps liquid carbon dioxide or fracturing fluid into the wellhead (19).

2. The carbon dioxide pre-energized fracturing equipment according to claim 1, characterized in that, The liquid carbon dioxide storage tank (1) is a horizontal tank composed of a protective layer, an insulation layer and an anti-corrosion layer, which are sequentially fitted from the outside to the inside.

3. The carbon dioxide pre-energized fracturing equipment according to claim 1, characterized in that, Each liquid carbon dioxide pumping device includes a liquid carbon dioxide storage tank (1), a second booster pump (11), a cooling pump (12), a first pressure gauge (13), a thermometer (14), and a first ultrasonic liquid level monitor (15); the second booster pump (11) and the cooling pump (12) are respectively connected to the inner cavity of the liquid carbon dioxide storage tank (1) through pipelines to maintain the preset pressure and temperature of the liquid carbon dioxide in the tank; the first pressure gauge (13) and the thermometer (14) are installed at the top of the liquid carbon dioxide storage tank (1) to collect the real-time pressure and real-time temperature of the inner cavity of the tank; the first ultrasonic liquid level monitor (15) is installed at the bottom of the liquid carbon dioxide storage tank (1) to monitor the liquid level height of the liquid carbon dioxide in the tank.

4. The carbon dioxide pre-energized fracturing equipment according to claim 1, characterized in that, Both the first and second integrated manifolds consist of a pipe body (201) and two supports (202); the pipe body (201) is a cylindrical pipe body with manifold outlets (204) at both ends, and multiple manifold inlets (203) are evenly distributed on its side wall in a straight line, and each manifold inlet (203) is provided with a cover; the pipe body (201) is horizontally fixed on the top surface of the two supports (202), and the two supports (202) are fixed to the ground at intervals.

5. The carbon dioxide pre-energized fracturing equipment according to claim 1, characterized in that, A second pressure gauge (16) is installed on the top of the buffer tank (3) to collect the pressure inside the buffer tank (3); an ultrasonic liquid level monitor (17) is installed at the bottom of the buffer tank (3) to monitor the liquid level of the liquid carbon dioxide inside the tank.

6. The carbon dioxide pre-energized fracturing equipment according to claim 1, characterized in that, A third ultrasonic liquid level monitor (18) is installed on the bottom side wall of the storage tank (502) to monitor the liquid level inside the tank.

7. The carbon dioxide pre-energized fracturing equipment according to claim 1, characterized in that, In the conical septum (506), the diameter of the through hole (5061) is 3~8mm; the spike (5062) is a conical spike with a height of 2~6mm.

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