Supercritical carbon dioxide cascade energizing jet fracturing device

Abstract

A liquid inlet is formed in the top end of the supercritical carbon dioxide cascade energizing jet flow fracturing device, and a liquid outlet is formed in the bottom end of the supercritical carbon dioxide cascade energizing jet flow fracturing device. A pressurizing baffle plate group is sequentially arranged in the inner cavity from top to bottom, and a pressurizing cavity is formed between every two adjacent pressurizing baffle plates; a magnetic top block is arranged above the center of each stage of pressurizing baffle, and the sizes of the magnetic top blocks are sequentially reduced from top to bottom; one end of the jacking column is connected into the pressurizing baffle, the other end of the jacking column penetrates through the corresponding magnetic suction jacking block, and the jacking column penetrating through the magnetic suction jacking block is sleeved with a spring; the middle pressurizing baffle is slidably connected with the lower portion of the inner cavity, and the other pressurizing baffles are fixedly connected with the inner cavity. Wherein the magnetic attraction force of each layer is larger than the spring elasticity of the layer, and the magnetic attraction force and the spring elasticity of each layer are sequentially increased from top to bottom. According to the utility model, the fluid mechanics principle is fully utilized, and the internal structure of the tubular column is optimized, so that the effective conversion and pressurization of the kinetic energy of fluid are realized, and the energy loss of the fluid in the conveying process is reduced.

Description

Technical Field

[0001] This utility model relates to the field of complex oil and gas reservoir stimulation technology, specifically to a supercritical carbon dioxide cascade-enhanced jet fracturing device. Background Technology

[0002] With the continuous development of oil and gas resources, traditional hydraulic fracturing technology can no longer meet the increasingly complex development needs of oil and gas reservoirs. Especially in the development of low-permeability and ultra-low-permeability oil and gas reservoirs, improving fracturing efficiency and effectiveness has become an urgent problem to be solved. Supercritical carbon dioxide (SCCO), as a novel fracturing fluid, is widely used in fracturing operations due to its unique physicochemical properties, such as low viscosity, high density, and good proppant carrying capacity. However, in practical applications, due to the long transport distance from surface storage equipment to the target underground reservoir, the kinetic energy of the SCCO fluid gradually decreases during transport, leading to a weakened proppant carrying capacity. Consequently, the energy transferred to the formation and the amount of proppant transported into the fractures also decrease, ultimately affecting the fracturing effect.

[0003] In existing supercritical carbon dioxide fracturing technologies, increasing pump pressure is typically used to improve fracturing efficiency. However, this method often leads to increased energy consumption, and the pressure and velocity attenuation issues during long-distance transport remain unresolved. Furthermore, due to insufficient proppant carrying capacity, proppant tends to accumulate in the wellbore and near-wellbore zone, resulting in poor fracturing performance and potentially triggering downhole accidents. Summary of the Invention

[0004] This invention addresses the problems of reduced fluid kinetic energy, insufficient sand-carrying capacity, and weak energy transfer to the formation in existing supercritical carbon dioxide technology by providing a supercritical carbon dioxide stepped energy-enhancing jet fracturing device.

[0005] The technical solution of this utility model is as follows:

[0006] A supercritical carbon dioxide stepped booster jet fracturing device has an inlet at the top and an outlet at the bottom. Its inner cavity is equipped with a series of booster baffles from top to bottom, with adjacent baffles forming a booster chamber. Each booster baffle has a magnetic top block above its center, with the size of the magnetic top blocks decreasing from top to bottom. It also includes a top column, one end of which is connected to the inside of the booster baffle, and the other end passes through the corresponding magnetic top block. A spring is fitted on the top column passing through the magnetic top block. The middle booster baffle is slidably connected to the lower part of the inner cavity, while the remaining booster baffles are fixedly connected to the inner cavity. The magnetic attraction force of each layer is greater than the spring force of that layer, and the magnetic attraction force and spring force increase sequentially from top to bottom.

[0007] The pressure boosting baffle assembly consists of three groups, which are arranged from top to bottom as a first-stage pressure boosting baffle, a second-stage pressure boosting baffle, and a third-stage pressure boosting baffle. The first-stage pressure boosting baffle and the second-stage pressure boosting baffle together form a first-stage pressure boosting chamber, and the second-stage pressure boosting baffle and the third-stage pressure boosting baffle together form a second-stage pressure boosting chamber.

[0008] The bottom of the inner cavity is provided with a crescent-shaped guide plate, which is at a 60° angle to the inner cavity. The crescent-shaped guide plate is provided with a frosted surface.

[0009] The primary pressure-boosting baffle is fixed to the inner cavity; a primary magnetic absorbing block is provided above the center of the primary pressure-boosting baffle, and a primary strong magnet is provided between the primary magnetic absorbing block and the primary pressure-boosting baffle; it also includes a primary top column, one end of which is connected to the inside of the primary pressure-boosting baffle, and the other end passes through the primary magnetic absorbing block. A primary spring is sleeved on the part of the primary top column that passes through the primary magnetic absorbing block, and the magnetic force of the primary strong magnet is greater than the elastic force of the primary spring; there are 4 primary top columns.

[0010] A secondary magnetic chuck is located above the center of the secondary booster baffle, and the secondary magnetic chuck is smaller than the primary magnetic chuck. A secondary strong magnet is located between the secondary magnetic chuck and the secondary booster baffle. The system also includes a secondary top column, one end of which is connected to the interior of the secondary booster baffle, and the other end of which passes through the secondary magnetic chuck. A secondary spring is fitted onto the portion of the secondary top column that passes through the secondary magnetic chuck, and the magnetic force of the secondary strong magnet is greater than the elastic force of the secondary spring. The secondary booster baffle is slidably connected to the inner cavity.

[0011] The three-stage pressure-boosting baffle is fixed to the inner cavity. A three-stage magnetic suction block is provided above the center of the three-stage pressure-boosting baffle. The three-stage magnetic suction block is smaller than the two-stage magnetic suction block. A three-stage strong magnet is provided between the three-stage magnetic suction block and the three-stage pressure-boosting baffle. It also includes a three-stage top column. One end of the three-stage top column is connected to the inside of the three-stage pressure-boosting baffle, and the other end passes through the three-stage magnetic suction block. A four-stage spring is sleeved on the part of the three-stage top column that passes through the three-stage magnetic suction block. The magnetic force of the three-stage strong magnet is greater than the elastic force of the four-stage spring.

[0012] A column is also provided between the secondary booster baffle and the tertiary booster baffle, and the secondary booster baffle and the column are connected by a three-stage spring.

[0013] The first-stage booster baffle is fixed to the inner cavity at both the top and bottom by a first-stage retainer. The second-stage booster baffle is provided with a second-stage retainer above the inner cavity, and the third-stage booster baffle is fixed to the inner cavity at the bottom by a third-stage retainer.

[0014] The elastic force of the first-level spring is less than the magnetic force of the first-level strong magnet, which is less than the elastic force of the second-level spring, which is less than the magnetic force of the second-level strong magnet, which is less than the elastic force of the third-level spring, which is less than the elastic force of the fourth-level spring, which is less than the magnetic force of the third-level strong magnet.

[0015] The technical advantages of this utility model are as follows:

[0016] (1) This utility model utilizes the principle of stepped pressurization to achieve a stepped increase in fluid pressure and velocity, ultimately achieving higher pressure and velocity ejection, thereby improving sand carrying capacity and increasing the energy transferred to the formation, thus improving the fracturing effect.

[0017] (2) This utility model makes full use of the principles of fluid mechanics. By optimizing the internal structure of the tubing string, it achieves effective conversion and pressurization of fluid kinetic energy and reduces energy loss of fluid during transportation. It has important practical application value for the development of complex oil and gas reservoirs. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of a supercritical carbon dioxide cascade-enhanced jet fracturing device according to the present invention.

[0019] Figure 2 This is a cross-sectional view of the AA line of the present invention.

[0020] Reference numerals: 1. Primary strong magnet; 2. Primary magnetic top block; 3. Primary pressure boosting baffle; 4. Primary spring; 5. Primary pressure boosting chamber; 6. Secondary strong magnet; 7. Secondary magnetic top block; 8. Secondary pressure boosting baffle; 9. Secondary spring; 10. Secondary pressure boosting chamber; 11. Tertiary spring; 12. Tertiary strong magnet; 13. Tertiary magnetic top block; 14. Tertiary pressure boosting baffle; 15. Quaternary spring; 16. Crescent-shaped guide plate; 17. Inner cavity; 18. Primary retainer; 19. Primary top column; 20. Secondary retainer; 21. Secondary top column; 22. Column; 23. Tertiary retainer; 24. Tertiary top column; 25. Liquid inlet; 26. Liquid outlet. Detailed Implementation

[0021] Example 1

[0022] A supercritical carbon dioxide stepped booster jet fracturing device has an inlet 25 at the top and an outlet 26 at the bottom. Its inner cavity 17 has a series of pressure-boosting baffles arranged from top to bottom, with adjacent baffles forming a pressure-boosting chamber. Each pressure-boosting baffle has a magnetic top block above its center, with the size of the magnetic top blocks decreasing from top to bottom. It also includes a top column, one end of which is connected to the inside of the pressure-boosting baffle, and the other end passes through the corresponding magnetic top block. A spring is fitted on the top column passing through the magnetic top block. The middle pressure-boosting baffle is slidably connected to the lower part of the inner cavity 17, while the remaining pressure-boosting baffles are fixedly connected to the inner cavity 17. The magnetic attraction force of each layer is greater than the spring force of that layer, and the magnetic attraction force and spring force increase sequentially from top to bottom.

[0023] Example 2

[0024] Based on Example 1, it also includes,

[0025] The pressure-boosting baffle assembly consists of three groups, arranged from top to bottom as a primary pressure-boosting baffle 3, a secondary pressure-boosting baffle 8, and a tertiary pressure-boosting baffle 14. The primary pressure-boosting baffle 3 and the secondary pressure-boosting baffle 8 form a primary pressure-boosting chamber 5, and the secondary pressure-boosting baffle 8 and the tertiary pressure-boosting baffle 14 form a secondary pressure-boosting chamber 10. A crescent-shaped guide plate 16 is provided at the bottom of the inner cavity 17, forming a 60° angle with the inner cavity 17. Each crescent-shaped guide plate 16 has a frosted surface.

[0026] Example 3

[0027] Based on Example 2, it also includes,

[0028] The primary pressure-boosting baffle 3 is fixed to the inner cavity 17; a primary magnetic suction block 2 is provided above the center of the primary pressure-boosting baffle 3, and a primary strong magnet 1 is provided between the primary magnetic suction block 2 and the primary pressure-boosting baffle 3; it also includes a primary top column 19, one end of which is connected to the inside of the primary pressure-boosting baffle 3, and the other end passes through the primary magnetic suction block 2. A primary spring 4 is sleeved on the part of the primary top column 19 that passes through the primary magnetic suction block 2, and the magnetic force of the primary strong magnet 1 is greater than the elastic force of the primary spring 4; there are 4 primary top columns 19.

[0029] A secondary magnetic top block 7 is provided above the center of the secondary booster baffle 8. The secondary magnetic top block 7 is smaller than the primary magnetic top block 2. A secondary strong magnet 6 is provided between the secondary magnetic top block 7 and the secondary booster baffle 8. It also includes a secondary top column 21. One end of the secondary top column 21 is connected to the interior of the secondary booster baffle 8, and the other end passes through the secondary magnetic top block 7. A secondary spring 9 is sleeved on the part of the secondary top column 21 that passes through the secondary magnetic top block 7. The magnetic force of the secondary strong magnet 6 is greater than the elastic force of the secondary spring 9. The secondary booster baffle 8 is slidably connected to the inner cavity 17.

[0030] The three-stage pressure-boosting baffle 14 is fixed to the inner cavity 17. A three-stage magnetic suction block 13 is provided above the center of the three-stage pressure-boosting baffle 14. The three-stage magnetic suction block 13 is smaller than the two-stage magnetic suction block 7. A three-stage strong magnet 12 is provided between the three-stage magnetic suction block 13 and the three-stage pressure-boosting baffle 14. It also includes a three-stage top column 24. One end of the three-stage top column 24 is connected to the inside of the three-stage pressure-boosting baffle 14, and the other end passes through the three-stage magnetic suction block 13. A four-stage spring 15 is sleeved on the part of the three-stage top column 24 that passes through the three-stage magnetic suction block 13. The magnetic force of the three-stage strong magnet 12 is greater than the elastic force of the four-stage spring 15.

[0031] A column 22 is also provided between the three-stage booster baffles 14, and the two-stage booster baffles 8 and the column 22 are connected by a three-stage spring 11.

[0032] The first-stage booster baffle 3 is fixed to the inner cavity 17 from both the top and bottom by a first-stage bracket 18. The second-stage booster baffle 8 is provided with a second-stage bracket 20 above the inner cavity 17. The third-stage booster baffle 14 is fixed to the inner cavity 17 from the bottom by a third-stage bracket 23.

[0033] The elastic force of the first-stage spring 4 is less than the magnetic force of the first-stage strong magnet 1, the elastic force of the second-stage spring 9, the magnetic force of the second-stage strong magnet 6, the elastic force of the third-stage spring 11, the elastic force of the fourth-stage spring 15, and the magnetic force of the third-stage strong magnet 12.

[0034] The specific implementation process of this embodiment is as follows:

[0035] First, the supercritical carbon dioxide stepped booster jet fracturing device of this invention is installed at the bottom of the fracturing pipeline. The supercritical carbon dioxide fracturing fluid enters from the top through the pipeline and accumulates and becomes pressurized after being blocked by the first-stage booster baffle 3. When the pressure exceeds the first-stage strong magnet 1, the first-stage magnetic chuck block 2 is lowered by hydraulic pressure. As the pressure increases, the first-stage magnetic chuck block 2 compresses the first-stage spring 4, and the first-stage magnetic chuck block 2 and the first-stage booster baffle 3 form a fluid channel. The supercritical carbon dioxide fracturing fluid that is pressurized at the top quickly enters the first-stage booster chamber 5. Then, the pressure in the first-stage booster chamber 5 is the same as the external pressure, and the first-stage magnetic chuck block 2 returns to its original position under the combined force of the first-stage strong magnet 1 and the first-stage spring 4. The above steps are then repeated until the pressure in the first-stage booster chamber 5 breaks through the resistance of the second-stage strong magnet 6 and the second-stage spring 9.

[0036] Subsequently, after the high-pressure supercritical carbon dioxide fracturing fluid in the primary pressurization chamber 5 enters the secondary pressurization chamber 10, as the fluid pressure increases, both the primary pressurization chamber 5 and the secondary pressurization chamber 10 are simultaneously filled with high-pressure supercritical carbon dioxide fracturing fluid. At this time, high-pressure supercritical carbon dioxide fracturing fluid continues to flow into the primary pressurization chamber 5, and the secondary magnetic chuck 7 closes under the action of the secondary strong magnet 6 and the secondary spring 9. The secondary pressurization baffle 8 begins to descend under the high pressure of the primary pressurization chamber 5, and the secondary magnetic chuck 7 closes more tightly, increasing the pressure in the secondary pressurization chamber 10. As the pressure in the primary pressurization chamber 5 increases, the secondary pressurization baffle 8 descends to the compression limit of the tertiary spring 11, and the fluid pressure in the secondary pressurization chamber 10 breaks through the resistance limit of the tertiary strong magnet 12 and the quaternary spring 15, and is rapidly ejected from the flow channel formed by the tertiary pressurization baffle 14.

[0037] Subsequently, the ejected high-pressure supercritical carbon dioxide fracturing fluid impacts the abrasive surface of the crescent-shaped guide plate 16. The abrasive surface can promote the rotational kinetic energy of the supporting sand, and the azimuth angle of the crescent-shaped guide plate 16 can also increase the flow of the high-pressure supercritical carbon dioxide fracturing fluid, forming a high-pressure, high-speed swirling supercritical carbon dioxide fracturing fluid before ejection.

[0038] Supercritical carbon dioxide fracturing fluid, accelerated by step-by-step pressurization, is ejected from the bottom, creating a high-pressure jet effect on the fracturing formation. This further enhances the proppant-carrying capacity of the supercritical carbon dioxide fracturing fluid, resulting in efficient proppant carrying and energy concentration.

Claims

1. A supercritical carbon dioxide stepped-energy-enhanced jet fracturing device, wherein a liquid inlet (25) is provided at the top and a liquid outlet (26) is provided at the bottom; characterized in that: The inner cavity (17) is provided with a pressure baffle group from top to bottom, and the adjacent pressure baffles form a pressure chamber; a magnetic top block is provided above the center of each pressure baffle, and the size of the magnetic top block decreases from top to bottom; it also includes a top column, one end of which is connected to the inside of the pressure baffle, and the other end passes through the corresponding magnetic top block. A spring is sleeved on the top column that passes through the magnetic top block; the pressure baffle in the middle is slidably connected to the bottom of the inner cavity (17), and the remaining pressure baffles are fixedly connected to the inner cavity (17); wherein, the magnetic attraction force of each layer is greater than the spring force of that layer, and the magnetic attraction force and spring force of each layer increase from top to bottom.

2. The supercritical carbon dioxide stepped-enhanced jet fracturing device according to claim 1, characterized in that: The pressure boosting baffle group consists of 3 groups, which are, from top to bottom, a first-stage pressure boosting baffle (3), a second-stage pressure boosting baffle (8) and a third-stage pressure boosting baffle (14). The first-stage pressure boosting baffle (3) and the second-stage pressure boosting baffle (8) form a first-stage pressure boosting chamber (5), and the second-stage pressure boosting baffle (8) and the third-stage pressure boosting baffle (14) form a second-stage pressure boosting chamber (10).

3. The supercritical carbon dioxide stepped-enhanced jet fracturing device according to claim 2, characterized in that: The bottom of the inner cavity (17) is provided with a crescent-shaped guide plate (16), which is at a 60° angle to the inner cavity (17). The crescent-shaped guide plate (16) is provided with a frosted surface.

4. The supercritical carbon dioxide stepped-enhanced jet fracturing device according to claim 2, characterized in that: The first-stage pressure baffle (3) is fixed in the inner cavity (17); a first-stage magnetic top block (2) is provided above the center of the first-stage pressure baffle (3), and a first-stage strong magnet (1) is provided between the first-stage magnetic top block (2) and the first-stage pressure baffle (3); it also includes a first-stage top column (19), one end of the first-stage top column (19) is connected to the inside of the first-stage pressure baffle (3), and the other end passes through the first-stage magnetic top block (2). A first-stage spring (4) is sleeved on the part of the first-stage top column (19) that passes through the first-stage magnetic top block (2), and the magnetic force of the first-stage strong magnet (1) is greater than the elastic force of the first-stage spring (4); the number of the first-stage top columns (19) is 4.

5. The supercritical carbon dioxide stepped-enhanced jet fracturing device according to claim 3, characterized in that: A secondary magnetic chuck block (7) is provided above the center of the secondary booster baffle (8). The secondary magnetic chuck block (7) is smaller than the primary magnetic chuck block (2). A secondary strong magnet (6) is provided between the secondary magnetic chuck block (7) and the secondary booster baffle (8). A secondary top column (21) is also provided. One end of the secondary top column (21) is connected to the interior of the secondary booster baffle (8), and the other end passes through the secondary magnetic chuck block (7). A secondary spring (9) is sleeved on the part of the secondary top column (21) that passes through the secondary magnetic chuck block (7). The magnetic force of the secondary strong magnet (6) is greater than the elastic force of the secondary spring (9). The secondary booster baffle (8) is slidably connected to the inner cavity (17).

6. The supercritical carbon dioxide stepped-enhanced jet fracturing device according to claim 4, characterized in that: The three-stage pressure baffle (14) is fixed in the inner cavity (17). A three-stage magnetic suction block (13) is provided above the center of the three-stage pressure baffle (14). The three-stage magnetic suction block (13) is smaller than the two-stage magnetic suction block (7). A three-stage strong magnet (12) is provided between the three-stage magnetic suction block (13) and the three-stage pressure baffle (14). It also includes a three-stage top column (24). One end of the three-stage top column (24) is connected to the inside of the three-stage pressure baffle (14), and the other end passes through the three-stage magnetic suction block (13). A four-stage spring (15) is sleeved on the part of the three-stage top column (24) that passes through the three-stage magnetic suction block (13). The magnetic force of the three-stage strong magnet (12) is greater than the elastic force of the four-stage spring (15).

7. The supercritical carbon dioxide stepped-enhanced jet fracturing device according to claim 6, characterized in that: A column (22) is also provided between the secondary booster baffle (8) and the tertiary booster baffle (14), and the secondary booster baffle (8) and the column (22) are connected by a three-stage spring (11).

8. The supercritical carbon dioxide stepped-energy-enhanced jet fracturing device according to claim 7, characterized in that: The first-stage booster baffle (3) is fixed to the inner cavity (17) above and below by a first-stage bracket (18). The second-stage booster baffle (8) is provided with a second-stage bracket (20) above the inner cavity (17). The third-stage booster baffle (14) is fixed to the inner cavity (17) below by a third-stage bracket (23).

9. The supercritical carbon dioxide stepped-enhanced jet fracturing device according to claim 8, characterized in that: The elastic force of the first-level spring (4) is less than the magnetic force of the first-level strong magnet (1) and less than the elastic force of the second-level spring (9) and less than the magnetic force of the second-level strong magnet (6) and less than the elastic force of the third-level spring (11) and less than the elastic force of the fourth-level spring (15) and less than the magnetic force of the third-level strong magnet (12).

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