Carbon dioxide near-dry fracturing equipment and method thereof

Abstract

The invention discloses carbon dioxide near-dry fracturing equipment and a method thereof, and relates to the technical field of geology. Through the arrangement of the connecting part stabilizing mechanisms, the connecting parts of the pipelines are limited in the positioning rods on the two sides of the hollow pipe, the structural strength of the connecting parts is improved, the connecting parts can better resist mechanical stress caused by internal pressure changes, carbon dioxide is prevented from expanding when being transmitted through the pipelines, and the service life of the pipelines is prolonged. The internal pressure rise causes larger separating force to the joint, and the force can be effectively counteracted through the limitation of the positioning rod on the pipeline, so that the connection stability is ensured, the joint is effectively protected, the joint is ensured not to loosen or leak under high pressure difference, leakage and accidents are reduced, and the service life of the pipeline is prolonged. And furthermore, the hollow pipe is arranged in a hollow mode and is relatively light, the installation convenience of the stabilizing mechanism at the connecting position is improved, the stabilizing mechanism is easier to disassemble and replace in the subsequent maintenance process, and the maintenance time and cost are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of geology, and in particular to a carbon dioxide quasi-dry fracturing device and a method thereof. Background Art

[0002] The CO2 quasi-dry fracturing equipment is an overall system used to implement the CO2 quasi-dry fracturing technology, including core components such as high-pressure pumps, sand mixing equipment, and cooling units. The CO2 quasi-dry fracturing technology is a technology that combines conventional hydraulic fracturing and CO2 dry fracturing. It aims to reduce damage to the reservoir and improve the fracturing effect by using a small amount of water and CO2 mixture.

[0003] In the prior art, a large number of high-pressure manifold connections are designed for fracturing operations. The connection work needs to be repeatedly checked to confirm whether each connection is leaking. Under high-pressure conditions, manual inspection of leak points has great uncertainty, and multiple rechecks are required to determine the specific location of the leak, which further increases the operation time. Leakage inspections usually require experienced operators, and the occupation of this part of human resources also increases production costs to a certain extent. In addition, the fracturing operation environment is relatively harsh, and frequent leakage inspections will increase the labor intensity of workers and increase the probability of errors. Once the leakage problem is not discovered for a long time, it will cause equipment damage and require larger-scale repairs or replacements, which will greatly increase costs. Furthermore, leakage usually means the release of high-pressure gas or liquid, which will cause fire, explosion or poisoning accidents, seriously threatening the safety of on-site personnel and the surrounding environment. In addition, during the inspection process, personnel need to be in close contact with leaking equipment, which increases the danger faced by the staff. Frequent leakage inspections and maintenance put the equipment in an unsafe working state, increasing the potential for accidents. Manual inspections mainly rely on experience and professional judgment of on-site workers, which are highly subjective and have certain limitations.

[0004] Therefore, a carbon dioxide quasi-dry fracturing device and method are proposed to solve the above problems. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a carbon dioxide quasi-dry fracturing device and method thereof to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions: A carbon dioxide quasi-dry fracturing device and method thereof, comprising: a pipeline, wherein a connection stabilizing mechanism is provided at an outer ring connection of the pipeline, an auxiliary lubrication mechanism is provided on one side of the connection stabilizing mechanism, the auxiliary lubrication mechanism comprises a plug valve, and a valve plug is screwed in the plug valve;

[0007] The connection stabilizing mechanism is used to assist the stability of the connection between the two pipelines and prevent leakage caused by loose connection at the connection;

[0008] The auxiliary lubrication mechanism is used to clean the outer ring of the pipeline and lubricate the valve plug after the work is completed.

[0009] Preferably, the connection stabilizing mechanism includes a base, which is placed on the ground and arranged below the pipeline. A hollow tube is fixedly connected to the base, and the outer rings at both ends of the hollow tube are rotatably connected to auxiliary rings. A worm is fixedly connected to the base, and an arc-shaped worm gear is meshingly connected above the worm, and the arc-shaped worm gear is fixedly connected to the outer ring of any auxiliary ring. An airbag ring is fixedly connected to the inner wall of the hollow tube, and the airbag ring fits the outer ring of the connection of the two pipelines. A first positioning block is symmetrically fixedly connected to the auxiliary ring with the center of the circle as the axis, and a positioning rod is fixedly connected to the first positioning block. The end of the positioning rod away from the first positioning block is slidably connected to a second positioning block, and the second positioning block is fixedly connected to the hollow tube.

[0010] Preferably, the auxiliary lubrication mechanism also includes a cover shell, which is fixedly connected to the outer ring of the auxiliary ring, an arc groove is provided on the outer ring of the cover shell at one end away from the auxiliary ring, an auxiliary tube is sleeved on the outer ring of the cover shell at one end away from the auxiliary ring, the lower end of the auxiliary tube is fixedly connected to the base, a guide groove is provided on the upper inner wall of the auxiliary tube, a multifunctional ring is slidably connected in the arc groove, and a T-bar is fixedly connected to the upper outer wall of the multifunctional ring.

[0011] Preferably, the auxiliary lubrication mechanism also includes a piston plate, the piston plate is fixedly connected to the end of the T-rod away from the multi-functional ring, the outer ring of the piston plate is slidably connected to a storage column, the storage column is fixedly connected to the plug valve, the end of the storage column away from the piston plate is fixedly connected to a conduit, the plug valve is fixedly connected to the end of the pipeline away from the base, the plug valve is fixedly connected to a liquid inlet valve, the end of the conduit away from the storage column is fixedly connected to the liquid inlet valve, and the outer ring of the valve plug is provided with a fluid groove.

[0012] Preferably, the worm gear has a built-in drive motor electrically connected to an external controller, the airbag ring is connected to an external inflation device, four groups of the first positioning block, positioning rod and second positioning block are arranged, and the first positioning block and the second positioning block are respectively staggered on the hollow tube and the auxiliary ring.

[0013] Preferably, the cover shell is composed of two circular tubes of different diameters, a wiping sheet is provided on the inner surface of the multifunctional ring, the T-bar is slidably connected in the arc groove, and the T-bar passes through the arc groove and is slidably connected in the guide groove.

[0014] Preferably, the storage column contains lubricating liquid, a lubricating liquid filling valve is provided on one side of the storage column, a one-way liquid outlet valve is built in the connection between the conduit and the storage column, and a flow port is opened in the middle of the valve plug to communicate with the inner cavity of the pipeline.

[0015] The carbon dioxide quasi-dry fracturing method comprises the following steps:

[0016] Step 1: Evaluate the characteristics of the target formation based on geological data, including rock mechanical parameters, geostress distribution and fracture development, design a fracturing plan based on the geological assessment results, and determine the fracturing scale, fracture layout and construction parameters;

[0017] Step 2: Ensure that all equipment involved, such as high-pressure pumps, booster equipment, pressurized sand mixing equipment, cooling units and monitoring equipment, are in good working condition, and prepare sufficient amounts of liquid carbon dioxide, proppant and chemical additives mainly composed of surfactants;

[0018] Step 3: Arrange the fracturing equipment, select the appropriate pipeline material and specifications according to the working medium, pressure and temperature requirements, connect the pipeline, use bolts and gaskets to tighten the connection, check whether the pipeline connection is firm, and ensure that there is no looseness or leakage;

[0019] Step 4: Align the plug valve with the connection port of the pipeline, insert the valve plug into the valve body, ensure that it fits the plug valve completely, and tighten the bolts with a wrench or wrench socket to ensure a firm connection;

[0020] Step 5: Start the high-pressure pump and start injecting the mixture into the target formation, and use monitoring equipment to track the injection pressure, flow rate, and temperature parameters in real time;

[0021] Step 6: After completing the injection of the designed amount of carbon dioxide and proppant, stop the high-pressure pump, perform necessary maintenance on the used equipment, and restore the site to its original state.

[0022] Compared with the prior art, the present invention provides a carbon dioxide quasi-dry fracturing device and method thereof, which has the following beneficial effects:

[0023] 1. By setting up a stabilizing mechanism at the connection, the connection of the pipeline is restricted within the positioning rods on both sides of the hollow tube, thereby improving the structural strength of the connection, enabling it to better resist the mechanical stress caused by changes in internal pressure, and preventing carbon dioxide from expanding when transmitted through the pipeline. The increase in internal pressure causes a greater separation force on the connection, and the restriction of the pipeline by the positioning rod can effectively offset these forces. Compared with the prior art, which uses manual inspection and only uses bolts and gaskets for fastening connections, the stability of the connection cannot be guaranteed. Under the setting of the stabilizing mechanism at the connection, the stability of the connection is better guaranteed, and the connection is further effectively protected to ensure that the connection will not loosen or leak under high pressure difference, thereby reducing the occurrence of leakage and accidents, thereby reducing long-term maintenance and repair costs. Furthermore, the hollow setting of the hollow tube is relatively light, which improves the installation convenience of the stabilizing mechanism at the connection, and is easier to disassemble and replace in subsequent maintenance, thereby reducing maintenance time and cost.

[0024] 2. Through the setting of the airbag ring, the connection of the pipeline is inflated and sealed. According to the shape of the pipeline connection, the pressure is evenly distributed to form a more perfect sealing surface, which effectively reduces the occurrence of small leaks. In addition, under the continuous operation of the external inflation device of the airbag ring, the continuous inflation of the airbag ring can form a continuous and dynamically adjusted sealing environment at the connection, ensuring that the sealing quality is always in the best state, reducing the sealing failure caused by over-tightening or uneven tightening, and further improving the overall sealing quality.

[0025] 3. Through the setting of the auxiliary lubrication mechanism, under the forward and reverse rotation movement of the auxiliary ring, the drive cover shell rotates forward and reverse, so that the T-rod controls the reciprocation of the multifunctional ring on the pipeline to clean the surface of the pipeline, and then when the auxiliary positioning rod is fitted with the pipeline, it prevents the presence of impurities on the pipeline from being embedded or attached to the pipe wall and changing the surface microstructure. This change will cause the surface roughness to decrease, thereby reducing the friction coefficient of the contact surface. The lower friction coefficient means that under the same positive pressure, the friction force will be reduced, thereby reducing the friction force between the positioning rod and the pipeline surface, and improving the tightening force of the positioning rod on the pipeline. Furthermore, while the T-rod reciprocates to drive the multifunctional ring for cleaning, the T-rod simultaneously serves as a drive for the lubrication operation. While the T-rod reciprocates, it controls the lubricating liquid in the storage column to be transported into the catheter, so that the valve plug is automatically lubricated after use, reducing the torque required for opening and closing the plug valve, realizing the rapid opening and closing of the plug valve, improving work efficiency, reducing the workload and error rate of manual maintenance, and extending the service life of the plug valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0027] Figure 2This is a structural diagram of the connection stabilizing mechanism and auxiliary lubrication mechanism of the present invention;

[0028] Figure 3 This is a structural diagram of the hollow tube of the present invention;

[0029] Figure 4 This is a disassembled structural diagram of the connection stabilizing mechanism of the present invention;

[0030] Figure 5 This is a cross-sectional structural diagram of the cover shell and auxiliary pipe of the present invention;

[0031] Figure 6 This is a disassembled structural diagram of the auxiliary lubrication mechanism of the present invention;

[0032] Figure 7 For the present invention Figure 6 The structure diagram at A is enlarged;

[0033] Figure 8 This is a disassembled structural diagram of the auxiliary lubrication mechanism of the present invention;

[0034] Fig. 9 This is a structural diagram of the local auxiliary lubrication mechanism of the present invention.

[0035] In the figure:

[0036] 1. Pipeline;

[0037] 2. Connection stabilizing mechanism; 21. Base; 22. Hollow tube; 23. Auxiliary ring; 24. Worm; 25. Arc worm gear; 26. Airbag ring; 27. First positioning block; 28. Positioning rod; 29. ​​Second positioning block;

[0038] 3. Auxiliary lubrication mechanism; 31. Cover; 32. Arc groove; 33. Auxiliary pipe; 34. Guide groove; 35. Multifunctional ring; 36. T-bar; 37. Piston plate; 38. Storage column; 39. Conduit; 310. Plug valve; 311. Liquid inlet valve; 312. Valve plug; 313. Fluid groove. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] The present invention is further described in detail below based on the accompanying drawings and embodiments.

[0041] Example

[0042] Please refer to Figures 1 to 4As shown:

[0043] In order to solve the problems mentioned in the technical solution, the embodiment of the present application provides a carbon dioxide quasi-dry fracturing device and method thereof, including: a pipeline 1, a connection stabilizing mechanism 2 is provided at the outer ring connection of the pipeline 1, an auxiliary lubrication mechanism 3 is provided on one side of the connection stabilizing mechanism 2, the auxiliary lubrication mechanism 3 includes a plug valve 310, and a valve plug 312 is screwed in the plug valve 310;

[0044] The connection stabilizing mechanism 2 is used to assist the stability of the connection between the two pipelines 1 to prevent leakage caused by loose connection at the connection. The connection stabilizing mechanism 2 includes a base 21, which is placed on the ground and arranged below the pipeline 1. A hollow tube 22 is fixedly connected to the base 21. The outer rings at both ends of the hollow tube 22 are rotatably connected to auxiliary rings 23. A worm 24 is fixedly connected to the base 21. The worm 24 is mainly used to drive the arc-shaped worm gear 25 to drive the auxiliary ring 23 to rotate, so as to fit with the pipeline 1 to prevent the pipeline 1 from loosening due to internal gas expansion during use. The worm 24 has a built-in drive motor and is electrically connected to an external controller. An arc-shaped worm gear 25 is meshed and connected above the worm 24. The arc-shaped worm gear 25 is fixedly connected to any one The outer ring of the auxiliary ring 23, the inner wall of the hollow tube 22 is fixedly connected with an airbag ring 26, the airbag ring 26 is mainly used to inflate and seal the connection after the two pipelines 1 are connected, the airbag ring 26 is connected with an external inflation device, the airbag ring 26 is attached to the outer ring of the connection of the two pipelines 1, the auxiliary ring 23 is symmetrically fixedly connected with a first positioning block 27 with the center of the circle as the axis, the first positioning block 27 is fixedly connected with a positioning rod 28, the end of the positioning rod 28 away from the first positioning block 27 is slidably connected with a second positioning block 29, the second positioning block 29 is fixedly connected to the hollow tube 22, the first positioning block 27, the positioning rod 28, and the second positioning block 29 are arranged in four groups, and the first positioning block 27 and the second positioning block 29 are staggered on the hollow tube 22 and the auxiliary ring 23 respectively;

[0045] For further examples, please refer to Figures 5 to 9 As shown:

[0046] The auxiliary lubrication mechanism 3 is used to clean the outer ring of the pipeline 1 and lubricate the valve plug 312 after the work is completed. The auxiliary lubrication mechanism 3 also includes a cover shell 31. The cover shell 31 is composed of two round tubes with different diameters. The cover shell 31 is fixedly connected to the outer ring of the auxiliary ring 23. The cover shell 31 is mainly used to protect part of the structure of the connection stabilization mechanism 2 to prevent it from being impacted during use. The outer ring of the end of the cover shell 31 away from the auxiliary ring 23 is provided with an arc groove 32, and the outer ring of the end of the cover shell 31 away from the auxiliary ring 23 is provided with an auxiliary pipe 33. The auxiliary pipe 33 The lower end is fixedly connected to the base 21, a guide groove 34 is provided on the inner wall above the auxiliary tube 33, a multifunctional ring 35 is slidably connected in the arc groove 32, a wiping sheet is provided on the inner surface of the multifunctional ring 35, a T-bar 36 is fixedly connected to the outer wall above the multifunctional ring 35, the T-bar 36 is mainly used to push the multifunctional ring 35 to slide on the pipeline 1 to clean the pipeline 1, and at the same time push the lubricating liquid in the storage column 38 to flow into the conduit 39, the T-bar 36 is slidably connected in the arc groove 32, and the T-bar 36 penetrates the arc groove 32 and is slidably connected in the guide groove 34;

[0047] The auxiliary lubrication mechanism 3 also includes a piston plate 37, which is fixedly connected to the end of the T-bar 36 away from the multifunctional ring 35. The outer ring of the piston plate 37 is slidably connected to a storage column 38, which is filled with lubricating liquid. A lubricating liquid filling valve is provided on one side of the storage column 38. The storage column 38 is fixedly connected to the plug valve 310, and the end of the storage column 38 away from the piston plate 37 is fixedly connected to a conduit 39. The conduit 39 is provided with a one-way liquid outlet valve at the connection of the storage column 38. The plug valve 310 is fixedly connected to the plug valve 310. 10 is fixedly connected to one end of the pipeline 1 away from the base 21, the plug valve 310 is fixedly connected with a liquid inlet valve 311, and the liquid inlet valve 311 is mainly used for the lubricating liquid to flow to the valve plug 312 for lubrication, the conduit 39 is fixedly connected to the liquid inlet valve 311 at one end away from the storage column 38, the valve plug 312 is provided with a flow port in the middle part to communicate with the inner cavity of the pipeline 1, and the outer ring of the valve plug 312 is provided with a fluid groove 313, and the fluid groove 313 is mainly used for assisting the lubricating liquid to flow on the valve plug 312.

[0048] A carbon dioxide quasi-dry fracturing method comprises the following steps:

[0049] Step 1: Evaluate the characteristics of the target formation based on geological data, including rock mechanical parameters, geostress distribution and fracture development, design a fracturing plan based on the geological assessment results, and determine the fracturing scale, fracture layout and construction parameters;

[0050] Step 2: Ensure that all equipment involved, such as high-pressure pumps, booster equipment, pressurized sand mixing equipment, cooling units and monitoring equipment, are in good working condition, and prepare sufficient amounts of liquid carbon dioxide, proppant and chemical additives mainly composed of surfactants;

[0051] Step 3: Arrange the fracturing equipment, select the appropriate material and specification of pipeline 1 according to the working medium, pressure and temperature requirements, connect pipeline 1, use bolts and gaskets to tighten the connection, check whether the connection of pipeline 1 is firm, and ensure that there is no looseness or leakage;

[0052] Step 4: Align the plug valve 310 with the connection port of the pipeline 1, insert the valve plug 312 into the valve body, ensure that it fits the plug valve 310 completely, and tighten the bolts with a wrench or a wrench socket to ensure a secure connection;

[0053] Step 5: Start the high-pressure pump and start injecting the mixture into the target formation, and use monitoring equipment to track the injection pressure, flow rate, and temperature parameters in real time;

[0054] Step 6: After completing the injection of the designed amount of carbon dioxide and proppant, stop the high-pressure pump, perform necessary maintenance on the used equipment, and restore the site to its original state.

[0055] Everything in the above example works like this:

[0056] In the initial state: the two pipelines 1 are in a connected state, the connection part of the pipeline 1 is located in the airbag ring 26, the multifunctional ring 35 is in contact with the outer circle of the end of the pipeline 1 away from the airbag ring 26, the arc groove 32 is located at the end of the guide groove 34 close to the hollow tube 22, and the lubricating liquid in the storage column 38 is not squeezed into the liquid inlet valve 311 through the conduit 39.

[0057] The following is a working process of the connection stabilizing mechanism 2 for assisting the stability of the connection between the two pipelines 1 and preventing leakage caused by a loose connection:

[0058] When in use, the built-in power supply of the worm 24 is started through an external controller to drive the worm 24 to rotate counterclockwise. When the worm 24 rotates counterclockwise, the arc-shaped worm wheel 25 is driven to rotate counterclockwise under the action of meshing transmission. Then, when the arc-shaped worm wheel 25 rotates counterclockwise, the auxiliary ring 23 rotates counterclockwise on the hollow tube 22 synchronously, thereby driving the first positioning block 27 connected to the auxiliary ring 23 to deflect counterclockwise. Under the action of this deflection, the positioning rods 28 connected to the first positioning block 27 all move toward the center of the hollow tube 22. When the positioning rods 28 deflect, the positioning rods 28 are close to each other, and the parallel distance between the positioning rods 28 is shortened. The positioning rod 28 slides in the second positioning block 29 toward the end away from the first positioning block 27, so as to control the centering offset between the positioning rods 28 to be close, fit with the outer surface of the pipeline 1, and tighten the connection of the pipeline 1. When the positioning rod 28 moves in the centering, the front end of the connection of the pipeline 1 is clamped to further prevent the two pipelines 1 from loosening and falling off due to subsequent internal gas expansion. After the positioning rod 28 fits with the pipeline 1, the external inflation device of the airbag ring 26 is started, and the airbag ring 26 is expanded. During the expansion of the airbag ring 26, the connection ends of the two pipelines 1 are adapted and blocked to further prevent leakage at the connection.

[0059] By setting the connection stabilizing mechanism 2, the connection of the pipeline 1 is restricted within the positioning rods 28 on both sides of the hollow tube 22, thereby improving the structural strength of the connection, enabling it to better resist the mechanical stress caused by internal pressure changes, and preventing carbon dioxide from expanding when transmitted through the pipeline 1. The internal pressure increase causes a greater separation force on the connection. The restriction of the pipeline 1 by the positioning rods 28 can effectively offset these forces. Compared with the prior art, which uses manual inspection and only uses bolts and gaskets for fastening connections, the stability of the connection cannot be guaranteed. With the setting of the connection stabilizing mechanism 2, the stability of the connection is better guaranteed, and the connection is further effectively protected to ensure that the connection will not loosen or leak under high pressure difference, thereby reducing the occurrence of leakage and accidents, thereby reducing long-term maintenance and repair costs. Furthermore, the hollow setting of the hollow tube 22 is relatively light, which improves the installation convenience of the connection stabilizing mechanism 2, and is easier to disassemble and replace in subsequent maintenance, thereby reducing maintenance time and cost.

[0060] By setting the airbag ring 26, the connection of the pipeline 1 is inflated and sealed. According to the shape of the connection of the pipeline 1, the pressure is evenly distributed to form a more perfect sealing surface, which effectively reduces the occurrence of small leaks. Moreover, under the continuous operation of the external inflation device of the airbag ring 26, the continuous inflation of the airbag ring 26 can form a continuous and dynamically adjusted sealing environment at the connection, ensuring that the sealing quality is always in the best state, reducing the sealing failure caused by over-tightening or uneven tightening, and further improving the overall sealing quality.

[0061] Please refer to the above working process Figures 1 to 4 .

[0062] The following is the working process of the auxiliary lubrication mechanism 3 for cleaning the outer ring of the pipeline 1 and lubricating the valve plug 312 after the work is completed:

[0063] When in use, the counterclockwise rotation of the auxiliary ring 23 synchronously drives the cover shell 31 fixed thereto to rotate counterclockwise synchronously, and the counterclockwise rotation of the cover shell 31 causes the arc groove 32 opened inside it to rotate synchronously with the counterclockwise rotation of the cover shell 31, so that the counterclockwise rotation of the arc groove 32 drives the T-shaped rod 36 to slide in the arc groove 32 and the guide groove 34 in the direction close to the auxiliary ring 23, and then under the movement of the T-shaped rod 36, the multifunctional ring 35 is synchronously driven to approach the auxiliary ring 23. At this time, the multifunctional ring 35 slides on the pipeline 1 and cleans the pipeline 1 through the internal wiper. After cleaning, the T-shaped rod 36 moves in the direction away from the auxiliary ring 23. At this time, the multifunctional ring 35 synchronously moves in the direction away from the auxiliary ring 23 and moves to the end of the cover shell 31 away from the auxiliary ring 23.

[0064] Furthermore, when the T-shaped rod 36 moves toward the auxiliary ring 23, the movement of the T-shaped rod 36 drives the piston plate 37 to move in the storage column 38 toward the end away from the storage column 38. At this time, the space in the storage column 38 increases, and the lubricating liquid enters the storage column 38 through the filling valve provided on the storage column 38.

[0065] Furthermore, after the fracturing operation is completed, the connection stabilizing mechanism 2 operates in the reverse direction according to the above working content to release the blockage of the connection of the pipeline 1. Then, in this state, the auxiliary ring 23 rotates clockwise in the opposite direction, thereby controlling the cover 31 to rotate clockwise synchronously. Under the setting of the arc groove 32, the T-shaped rod 36 is pushed to move in the direction of the storage column 38, so that the piston plate 37 moves forward in the storage column 38, pushing the lubricating fluid stored in the storage column 38 to be squeezed into the conduit 39, and then enters the inside of the plug valve 310 through the liquid inlet valve 311. The lubricating fluid is applied to the valve plug 312 through the setting of the fluid groove 313, so as to avoid the situation that the plug valve 310 cannot be opened due to lack of timely lubrication after the fracturing operation is completed;

[0066] Through the setting of the auxiliary lubrication mechanism 3, under the forward and reverse rotation movement of the auxiliary ring 23, the cover 31 is driven to rotate forward and reverse, so as to control the reciprocation of the multifunctional ring 35 on the pipeline 1 through the T-bar 36, so as to clean the surface of the pipeline 1, and then to prevent the existence of impurities on the pipeline 1 from being embedded or attached to the pipe wall when the auxiliary positioning rod 28 is attached to the pipeline 1, and changing the microstructure of the surface. This change will cause the surface roughness to decrease, thereby reducing the friction coefficient of the contact surface. A lower friction coefficient means that under the same positive pressure, the friction force will be reduced, so that the positioning rod 28 and the pipeline 1 are closer. When the friction force of the surface restriction is reduced, the tightening force of the positioning rod 28 on the pipeline 1 is increased. Furthermore, while the T-rod 36 reciprocates to drive the multi-function ring 35 for cleaning, the T-rod 36 simultaneously serves as a drive for lubrication. The T-rod 36 reciprocates while controlling the lubricating liquid in the storage column 38 to be transported to the conduit 39, so that the valve plug 312 is automatically lubricated after use, reducing the torque required for opening and closing the plug valve 310, realizing rapid opening and closing of the plug valve 310, improving work efficiency, reducing the workload and error rate of manual maintenance, and extending the service life of the plug valve 310.

[0067] Please refer to the above working process Figures 5 to 9 .

[0068] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0069] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A carbon dioxide quasi-dry fracturing device, comprising: A pipeline (1), characterized in that a connection stabilizing mechanism (2) is provided at an outer ring connection of the pipeline (1), an auxiliary lubrication mechanism (3) is provided on one side of the connection stabilizing mechanism (2), the auxiliary lubrication mechanism (3) comprises a plug valve (310), and a valve plug (312) is screwed into the plug valve (310); The connection stabilizing mechanism (2) is used to assist in stabilizing the connection between the two pipelines (1) and to prevent leakage caused by a loose connection at the connection; The auxiliary lubrication mechanism (3) is used to clean the outer ring of the pipeline (1) and lubricate the valve plug (312) after the work is completed.

2. A carbon dioxide quasi-dry fracturing device according to claim 1, characterized in that: The connection stabilizing mechanism (2) comprises a base (21), the base (21) is placed on the ground, the base (21) is arranged below the pipeline (1), a hollow tube (22) is fixedly connected to the base (21), both ends of the outer ring of the hollow tube (22) are rotatably connected to auxiliary rings (23), a worm (24) is fixedly connected to the base (21), an arc-shaped worm wheel (25) is meshedly connected above the worm (24), and the arc-shaped worm wheel (25) is fixedly connected to any one of the auxiliary rings (23). ), the inner wall of the hollow tube (22) is fixedly connected with an airbag ring (26), the airbag ring (26) is fitted to the outer circle of the connection between the two pipelines (1), the auxiliary ring (23) is symmetrically fixedly connected with a first positioning block (27) with the center of the circle as the axis, the first positioning block (27) is fixedly connected with a positioning rod (28), the end of the positioning rod (28) away from the first positioning block (27) is slidably connected with a second positioning block (29), and the second positioning block (29) is fixedly connected to the hollow tube (22).

3. The carbon dioxide quasi-dry fracturing equipment according to claim 1, characterized in that: The auxiliary lubrication mechanism (3) further comprises a cover shell (31), wherein the cover shell (31) is fixedly connected to the outer ring of the auxiliary ring (23), an arc groove (32) is provided on the outer ring of the end of the cover shell (31) away from the auxiliary ring (23), an auxiliary tube (33) is sleeved on the outer ring of the end of the cover shell (31) away from the auxiliary ring (23), the lower end of the auxiliary tube (33) is fixedly connected to the base (21), a guide groove (34) is provided on the upper inner wall of the auxiliary tube (33), a multifunctional ring (35) is slidably connected in the arc groove (32), and a T-shaped rod (36) is fixedly connected to the upper outer wall of the multifunctional ring (35).

4. A carbon dioxide quasi-dry fracturing device according to claim 3, characterized in that: The auxiliary lubrication mechanism (3) further comprises a piston plate (37), wherein the piston plate (37) is fixedly connected to one end of the T-shaped rod (36) away from the multifunctional ring (35), the outer ring of the piston plate (37) is slidably connected to a storage column (38), the storage column (38) is fixedly connected to a plug valve (310), the end of the storage column (38) away from the piston plate (37) is fixedly connected to a conduit (39), the plug valve (310) is fixedly connected to one end of the pipeline (1) away from the base (21), the plug valve (310) is fixedly connected to a liquid inlet valve (311), the end of the conduit (39) away from the storage column (38) is fixedly connected to the liquid inlet valve (311), and the outer ring of the valve plug (312) is provided with a fluid groove (313).

5. The carbon dioxide quasi-dry fracturing equipment according to claim 2, characterized in that: The worm (24) has a built-in drive motor electrically connected to an external controller, the airbag ring (26) is connected to an external inflation device, and four groups of the first positioning block (27), the positioning rod (28), and the second positioning block (29) are provided. The first positioning block (27) and the second positioning block (29) are respectively arranged in an alternating manner on the hollow tube (22) and the auxiliary ring (23).

6. The carbon dioxide quasi-dry fracturing equipment according to claim 3, characterized in that: The cover shell (31) is composed of two circular tubes of different diameters. The inner surface of the multifunctional ring (35) is provided with a wiping sheet. The T-shaped rod (36) is slidably connected in the arc groove (32). The T-shaped rod (36) penetrates the arc groove (32) and is slidably connected in the guide groove (34).

7. The carbon dioxide quasi-dry fracturing equipment according to claim 4, characterized in that: The storage column (38) contains lubricating liquid, a lubricating liquid filling valve is arranged on one side of the storage column (38), a one-way liquid outlet valve is arranged at the connection between the conduit (39) and the storage column (38), and a flow opening is arranged in the middle of the valve plug (312) to communicate with the inner cavity of the pipeline (1).

8. A carbon dioxide quasi-dry fracturing method, applied to a carbon dioxide quasi-dry fracturing device as claimed in any one of claims 1 to 7, characterized in that: The following steps are involved: Step 1: Evaluate the characteristics of the target formation based on geological data, including rock mechanical parameters, geostress distribution and fracture development, design a fracturing plan based on the geological assessment results, and determine the fracturing scale, fracture layout and construction parameters; Step 2: Ensure that all equipment involved, such as high-pressure pumps, booster equipment, pressurized sand mixing equipment, cooling units and monitoring equipment, are in good working condition, and prepare sufficient amounts of liquid carbon dioxide, proppant and chemical additives mainly composed of surfactants; Step 3: Arrange the fracturing equipment, select appropriate materials and specifications of the pipeline (1) according to the working medium, pressure and temperature requirements, connect the pipeline (1), use bolts and gaskets to tighten the connection, and check whether the connection of the pipeline (1) is firm to ensure that there is no looseness or welding leakage; Step 4: Align the plug valve (310) with the connection port of the pipeline (1), insert the valve plug (312) into the valve body, ensure that it fits completely with the plug valve (310), and tighten the bolts with a wrench or a wrench socket to ensure a secure connection; Step 5: Start the high-pressure pump and start injecting the mixture into the target formation, and use monitoring equipment to track the injection pressure, flow rate, and temperature parameters in real time; Step 6: After completing the injection of the designed amount of carbon dioxide and proppant, stop the high-pressure pump, perform necessary maintenance on the used equipment, and restore the site to its original state.

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