A fracturing process with alternating temporary plugging and energy enhancement in tight oil horizontal well fractures

Abstract

The present invention relates to the technical field of oil production engineering, and in particular to a fracturing process for alternating temporary plugging and energy enhancement in tight oil horizontal well fractures. The present invention obtains the oil layer thickness, the porosity of the tight oil horizontal well, and the length of the horizontal well by logging the tight oil horizontal well, and performs energy enhancement fracturing and temporary plugging fracturing alternately on the construction section of the tight oil horizontal well to improve the oil production effect after fracturing. In the energy enhancement fracturing section, the injection amount of carbon dioxide is calculated, which improves the adaptability of the present invention. The diffusion range is predicted before the temporary plugging fracturing section to determine the position of the temporary plugging fracturing construction section, which improves the fracturing efficiency. After a temporary plugging agent is injected to plug the end of the fracture during the temporary plugging fracturing construction, the diffusion characterization parameters for the temporary plugging fracturing are calculated, and the injection pressure when a low-viscosity fracturing fluid is injected again is adjusted, thereby effectively improving the horizontal well formation energy, increasing the fracture control volume, effectively mobilizing the reservoir crude oil, and improving the recovery degree.

Description

Technical Field

[0001] The present invention relates to the technical field of oil production engineering, and in particular to a fracturing process for alternating temporary plugging and energy enhancement in tight oil horizontal well fractures. Background Art

[0002] Tight oil horizontal wells belong to ultra-low permeability reservoirs, making water injection impossible and requiring extraction to rely on natural energy. Conventional fracturing methods suffer from issues such as insufficient stimulation and rapid post-fracturing production decline. A horizontal well fracturing process that can effectively increase formation energy and stimulate stimulation is urgently needed.

[0003] Chinese patent authorization announcement number: CN115992683A, discloses a formation fluid injection energization and temporary plugging and diversion coordinated fracturing method, comprising the following steps: selecting a deep formation development area, injecting a second preset volume of fracturing fluid into the development area at a second preset displacement to form a main fracture in the formation of the development area; obtaining construction parameters of the main fracture formation process, and calculating the main fracture length according to the construction parameters; determining the radius of the maximum principal stress field reversal zone within a certain area of ​​the main fracture according to the main fracture length; defining a dimensionless time, and calculating the main fracture length according to the dimensionless time. The optimal dimensionless time is determined based on the changing relationship between the dimensional time and the ratio of the radius of the maximum principal stress field inversion zone to the length of the main fracture; the optimal injection time is calculated based on the optimal dimensionless time, and injection fluid is injected into the deep formation of the development area at a third preset displacement, and the injection time is the optimal dimensionless time; a fourth preset volume of temporary plugging and diverting fluid is injected into the deep formation of the development area at a fourth preset displacement, and a fifth preset volume of fracturing fluid is injected into the deep formation of the development area at a fifth preset displacement, thereby forming multiple artificial fractures on the main fracture.

[0004] In existing technologies, carbon dioxide is used as an energizing medium to increase formation energy. However, technical background research shows that there is currently a lack of a process that integrates carbon dioxide energization and improvement of transformation effects for tight oil horizontal wells, making it difficult to fully utilize the energizing and displacement effects of carbon dioxide. At the same time, there are problems such as insufficient development and transformation, and rapid decline in production after fracturing. Summary of the Invention

[0005] To this end, the present invention provides a fracturing process that alternates temporary plugging and energy enhancement in the fractures of tight oil horizontal wells, which is used to solve the problems of lack of a process that integrates carbon dioxide energy enhancement and improvement of the transformation effect for tight oil horizontal wells, making it difficult to fully exert the energy enhancement and displacement effects of carbon dioxide, as well as insufficient transformation and rapid decline in production after fracturing.

[0006] To achieve the above objectives, the present invention provides a fracturing process for alternating temporary plugging and energy enhancement in tight oil horizontal well fractures, comprising:

[0007] Step S1, performing well logging on a tight oil horizontal well, wherein the well logging includes obtaining the oil layer thickness, porosity, and horizontal well length;

[0008] Step S2, performing energy-enhanced fracturing on the construction section of the tight oil horizontal well, including perforating the construction section, injecting carbon dioxide and low-viscosity fracturing fluid to form fractures, and injecting high-viscosity fracturing fluid carrying proppant into the fractures to complete the energy-enhanced fracturing;

[0009] The injection amount of carbon dioxide is determined based on the thickness, porosity and length of the oil layer;

[0010] Step S3, determining the diffusion range by measuring the change of electromagnetic intensity at different positions on the surface of the construction section during the energy-boosting fracturing process, so as to determine the construction distance relative to the construction section, and performing temporary plugging and fracturing on the construction section, including:

[0011] The construction section is perforated, low-viscosity fracturing fluid is injected to form fractures, high-viscosity fracturing fluid carrying proppant is injected into the fractures, and then a temporary plugging agent is injected to plug the ends of the fractures. Gradient diffusion characteristic difference values ​​and diffusion ranges are determined based on changes in electromagnetic intensity at different surface locations corresponding to the construction section to calculate diffusion characterization parameters for temporary plugging fracturing. The injection pressure when the low-viscosity fracturing fluid is injected again is adjusted based on the diffusion characterization parameters. After the low-viscosity fracturing fluid is injected to open branch fractures at the corresponding injection pressure, high-viscosity fracturing fluid is injected to carry proppant into the branch fractures to complete temporary plugging fracturing.

[0012] Step S4, repeating steps S2 and S3 until all construction sections cover the tight oil horizontal well.

[0013] Furthermore, in step S2, the injection amount of carbon dioxide is calculated according to formula (1):

[0014]

[0015] In formula (1), represents the injection rate of carbon dioxide, represents the porosity, represents the injection volume empirical coefficient, represents the oil layer thickness, represents the control radius, represents the horizontal well length, represents the conversion coefficient between the mass of liquid carbon dioxide and gaseous carbon dioxide at formation temperature and pressure, and represents the length correlation coefficient.

[0016] Furthermore, in step S2, the length correlation coefficient n is a variable parameter, and n is positively correlated with the length of the horizontal well.

[0017] Furthermore, in step S3, the diffusion range is determined according to the change of electromagnetic intensity at different locations on the surface of the construction section corresponding to the energy-boosting fracturing process, including:

[0018] Determine the ground location point corresponding to the perforation point,

[0019] Determine the farthest point where the electromagnetic intensity can be measured to meet the change conditions as the diffusion point;

[0020] Determining a distance between the ground location point and the diffusion point, and determining the distance as a diffusion range;

[0021] The change condition includes that the change amplitude of the electromagnetic intensity is greater than a predetermined change amplitude threshold value.

[0022] Furthermore, in step S3, the construction distance is determined according to the diffusion range, wherein:

[0023] The construction distance is positively correlated with the diffusion range.

[0024] Furthermore, in step S3, the gradient diffusion characteristic difference value is determined according to the change of electromagnetic intensity at different positions on the surface corresponding to the construction section, including:

[0025] Determine the ground location point corresponding to the perforation point,

[0026] Determining a first measurement point at a first reference distance from the ground location point and a second measurement point at a second reference distance from the ground location point;

[0027] Determining the difference between the average electromagnetic intensity at the first measurement point and the average electromagnetic intensity at the second measurement point during the period of injecting low-viscosity fracturing fluid to form a fracture, to obtain a gradient diffusion characteristic difference value;

[0028] The first measurement point, the second measurement point, and the ground location point are located on the same straight line, and the first reference distance is smaller than the second reference distance.

[0029] Furthermore, in step S3, the diffusion characterization parameter of temporary plugging fracturing is calculated according to formula (2):

[0030]

[0031] In formula (2), represents the diffusion characterization parameter, represents the gradient diffusion characteristic difference value, represents the reference gradient diffusion characteristic difference value, represents the diffusion range, represents the reference diffusion range, represents the gradient diffusion characteristic difference value influence coefficient, and represents the diffusion range influence coefficient.

[0032] Furthermore, in step S3, the injection pressure of the low-viscosity fracturing fluid is adjusted according to the diffusion characterization parameter, wherein:

[0033] If the diffusion characterization parameter is greater than the baseline diffusion characterization parameter threshold, reducing the injection pressure;

[0034] If the diffusion characterization parameter does not exceed the baseline diffusion characterization parameter threshold, the injection pressure is kept unchanged;

[0035] If the diffusion characterization parameter is less than the baseline diffusion characterization parameter threshold, increase the injection pressure.

[0036] Furthermore, in step S1, the well needs to be washed with clean water until the water quality at the inlet and outlet of the tight oil horizontal well is consistent.

[0037] Furthermore, the method further includes step S5, wherein after all construction is completed, the well is shut down for pressure diffusion.

[0038] Compared with the prior art, the present invention obtains the oil layer thickness, porosity and length of the tight oil horizontal well by logging the tight oil horizontal well, and performs alternating construction of energy-boosting fracturing and temporary plugging fracturing on the construction section of the tight oil horizontal well to improve the oil production effect after fracturing. In the energy-boosting fracturing section, the injection amount of carbon dioxide is calculated, which improves the adaptability of the present invention. The diffusion range is predicted before the temporary plugging fracturing section to determine the position of the temporary plugging fracturing construction section, which improves the fracturing efficiency. After the temporary plugging agent is injected to plug the end of the crack during the temporary plugging fracturing construction, the diffusion characterization parameters for the temporary plugging fracturing are calculated, and the injection pressure when the low-viscosity fracturing fluid is injected again is adjusted, thereby effectively improving the horizontal well formation energy, increasing the fracture control volume, effectively mobilizing the reservoir crude oil, and improving the recovery degree.

[0039] In particular, the present invention performs energy-enhanced fracturing by calculating the injection amount of carbon dioxide. In actual practice, when performing the carbon dioxide injection operation, the injection amount of carbon dioxide needs to be determined, and the injection amount of carbon dioxide will be affected by many factors. Injecting an inappropriate amount of carbon dioxide may not only cause waste of carbon dioxide, but also reduce mining efficiency. Based on the above problems, the present invention determines the carbon dioxide injection amount formula in combination with actual conditions, improves the precise control of the carbon dioxide injection amount, improves mining efficiency, and effectively improves the alternation of temporary plugging and energy enhancement in the fracture to improve the oil production effect after fracturing.

[0040] In particular, the present invention determines the construction distance relative to the construction section through the diffusion range. In actual situations, the energized fracturing section will produce many fine cracks. If the diffusion range is not predicted, the selected position of the plugging fracturing section may be too close or too far. If it is too close, it will interfere with the cracks of the energized fracturing, and if it is too far, some areas will not be fractured. Both situations will lead to a decrease in the final production. To solve the above problems, the present invention predicts the diffusion range and determines the position of the plugging fracturing section outside the diffusion range, providing a data basis for the subsequent adjustment of the injection pressure of the low-viscosity fracturing fluid.

[0041] In particular, the present invention calculates the diffusion characterization parameters by determining the gradient diffusion characteristic difference value and the diffusion range, thereby providing data support for the subsequent adjustment of the injection pressure of the low-viscosity fracturing fluid. In actual situations, when opening branch fractures, the injection pressure of the low-viscosity fracturing fluid may not be appropriate. Moreover, due to the different geological properties of different construction sections, excessive injection pressure under the influence of multiple factors may cause excessive diffusion of the fractures and interfere with the fractures of the energy-enhanced fracturing. Excessive injection pressure may reduce the diffusion range of the fractures. Both situations will lead to a decrease in subsequent production. In order to solve the above problems, the present invention proposes to adjust the injection pressure of the low-viscosity fracturing fluid based on the diffusion characterization parameters. If the diffusion characterization parameter is greater than the baseline diffusion characterization parameter threshold, the injection pressure is reduced. If the diffusion characterization parameter does not exceed the baseline diffusion characterization parameter threshold, the injection pressure is kept unchanged. If the diffusion characterization parameter is less than the baseline diffusion characterization parameter threshold, the injection pressure is increased, thereby effectively improving the horizontal well formation energy, increasing the fracture control volume, effectively mobilizing the reservoir crude oil, and improving the recovery rate.

[0042] In particular, the present invention adopts a fracturing process of alternating temporary plugging and energy enhancement in the fractures of tight oil horizontal wells. In actual situations, during the fracturing construction process, usually only energy enhancement fracturing construction or only temporary plugging fracturing construction is carried out. The operation is single, resulting in low cracking efficiency and thus low mining efficiency. In order to improve the final mining efficiency, the present invention considers alternating fracturing construction of energy enhancement and temporary plugging, thereby making the cracking directions of the fractures different, effectively improving the horizontal well formation energy, increasing the fracture control volume, effectively mobilizing the reservoir crude oil, and improving the recovery rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 Schematic diagram of the method steps of a fracturing process for alternating temporary plugging and energy enhancement in a tight oil horizontal well fracture according to an embodiment of the invention;

[0044] Figure 2 A logic block diagram for determining that the farthest point in an embodiment of the present invention is a diffusion point;

[0045] Figure 3 A logic block diagram for determining the injection pressure when injecting low-viscosity fracturing fluid according to an embodiment of the present invention;

[0046] Figure 4 This is a schematic diagram of the cracks after completion of the fracturing process of alternating temporary plugging and energy enhancement in the fractures of a tight oil horizontal well according to an embodiment of the invention. DETAILED DESCRIPTION

[0047] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are merely used to explain the present invention and are not intended to limit the present invention.

[0048] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0049] It should be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0050] See also Figures 1 to 4 As shown, Figure 1 This is a schematic diagram of the method steps of the fracturing process for alternating temporary plugging and energy enhancement in tight oil horizontal well fractures according to an embodiment of the invention. Figure 2 A logic block diagram for determining that the farthest point in an embodiment of the invention is a diffusion point. Figure 3 A logic block diagram for determining the injection pressure when injecting low-viscosity fracturing fluid according to an embodiment of the invention. Figure 4 A schematic diagram of the cracks after completion of a fracturing process for alternating temporary plugging and energy enhancement in a tight oil horizontal well fracture according to an embodiment of the invention. A fracturing process for alternating temporary plugging and energy enhancement in a tight oil horizontal well fracture according to the present invention comprises:

[0051] Step S1, performing well logging on a tight oil horizontal well, wherein the well logging includes obtaining the oil layer thickness, the porosity of the tight oil horizontal well, and the length of the horizontal well;

[0052] Step S2, performing energy-enhanced fracturing on the construction section of the tight oil horizontal well, including perforating the construction section, injecting carbon dioxide and low-viscosity fracturing fluid to form fractures, and injecting high-viscosity fracturing fluid carrying proppant into the fractures to complete the energy-enhanced fracturing;

[0053] The injection amount of carbon dioxide is determined based on the thickness of the oil layer, the porosity of the tight oil horizontal well, and the length of the horizontal well;

[0054] Step S3, determining the diffusion range by measuring the change of electromagnetic intensity at different positions on the surface of the construction section during the energy-boosting fracturing process, so as to determine the construction distance relative to the construction section, and performing temporary plugging and fracturing on the construction section, including:

[0055] The construction section is perforated, low-viscosity fracturing fluid is injected to form a fracture, high-viscosity fracturing fluid is injected to carry proppant into the fracture, and then a temporary plugging agent is injected to plug the end of the fracture. The gradient diffusion characteristic difference value and the diffusion range are determined based on the change of electromagnetic intensity at different positions on the surface corresponding to the construction section to calculate the diffusion characterization parameter for temporary plugging fracturing. The injection pressure when the low-viscosity fracturing fluid is injected again is adjusted according to the diffusion characterization parameter. After the low-viscosity fracturing fluid is injected at the corresponding injection pressure, high-viscosity fracturing fluid is injected to carry the proppant into the fracture to complete the temporary plugging fracturing.

[0056] Step S4, repeating steps S2 and S3 until all construction sections cover the tight oil horizontal well.

[0057] Specifically, there is no specific limitation on the process of performing fracturing, and those skilled in the art can set it according to their needs. For example, before well washing, a scraping and well-passing string should be set in the tight oil horizontal well, and a well control device for fracturing should be configured;

[0058] After well washing, a fracturing string should be run into the tight oil horizontal well, a fracturing wellhead should be installed, and a fracturing manifold should be connected. This is an existing technology and will not be described in detail.

[0059] It is understandable that in order to ensure that downhole pressure can be effectively controlled and blowouts can be prevented, the well control device must be located between the wellhead and the drilling operation area and must be no less than 15 meters away from the wellhead.

[0060] The injection amount of carbon dioxide is calculated according to formula (1):

[0061]

[0062] In formula (1), M represents the injection amount of carbon dioxide, Represents porosity, P v represents the injection volume empirical coefficient, A represents the oil layer thickness, B represents the control radius, H represents the horizontal well length, S represents the conversion coefficient between the mass of liquid carbon dioxide and gaseous carbon dioxide at formation temperature and pressure, and n represents the length correlation coefficient.

[0063] In this embodiment, P v Take 0.3, S take 506;

[0064] In this embodiment, the average porosity is 12.2%, the half-thickness of the oil layer is 2.0 m, the control radius is 250 m, the horizontal well length is 300 m, and the length correlation coefficient is 11. Then, the injection amount of carbon dioxide in this section M = 12.2 × 0.3 × π × 2 × 250 × 300 / 506 / 11 = 3100 t.

[0065] Specifically, the length correlation coefficient n is a variable parameter, and n is positively correlated with the length of the horizontal well.

[0066] In the embodiment, the horizontal well length H is compared with the reference horizontal well length H0.

[0067] Optional, n = H / H0;

[0068] Among them, H0 represents the benchmark construction length, and H0 is selected within [15m, 20m].

[0069] Specifically, the diffusion range is determined based on the change in electromagnetic intensity at different locations on the surface of the construction section during the energy-boosting fracturing process, including:

[0070] Determine the ground location point corresponding to the perforation point,

[0071] Determine the farthest point where the electromagnetic intensity can be measured to meet the change conditions as the diffusion point;

[0072] Determining a distance between the ground location point and the diffusion point, and determining the distance as a diffusion range;

[0073] The change condition includes that the change amplitude of the electromagnetic intensity is greater than a predetermined change amplitude threshold value.

[0074] It can be understood that the perforation point is underground, the ground position point is on the surface, the perforation point and the ground position point are in the same straight line, and the straight line is perpendicular to the horizontal plane.

[0075] It is understandable that as the fracturing fluid diffuses underground along the cracks, it will cause the electromagnetic intensity at the corresponding position on the ground to change, which will not be elaborated here.

[0076] Specifically, the predetermined change amplitude threshold value P0 is pre-set, wherein the change intensity average Pe when the electromagnetic intensity at different positions on the surface of several construction sections corresponding to the energized fracturing process changes is obtained in advance, and P0 is set to Pe×g, where g represents the change coefficient, 0.75<g<0.85.

[0077] Specifically, there is no specific limitation on the testing method of electromagnetic intensity at different locations on the ground. For example, wide-area electromagnetic monitoring technology can be used. It supplies alternating current to the wellbore on the ground to stimulate the fracturing fluid in the cracks to produce an electromagnetic antenna effect, and deploys a receiving system on the surface to measure the electromagnetic intensity in real time. Of course, other methods can also be used, which will not be repeated here.

[0078] Specifically, the construction distance is determined based on the diffusion range, where the construction distance is positively correlated with the diffusion range.

[0079] In an embodiment, the diffusion range F is compared with a predetermined diffusion range F0,

[0080] If F>F0, then set

[0081] If F≤F0, set V=V0;

[0082] Among them, F0 represents the predetermined diffusion range, F0 is selected within [5m, 10m], V0 represents the benchmark construction distance, V0 is selected within the interval [10m, 15m], and V represents the construction distance.

[0083] Specifically, the gradient diffusion characteristic difference value is determined according to the change of electromagnetic intensity at different locations on the surface of the construction section, including:

[0084] Determine the ground location point corresponding to the perforation point,

[0085] Determining a first measurement point at a first reference distance from the ground location point and a second measurement point at a second reference distance from the ground location point;

[0086] Determining the difference between the average electromagnetic intensity at the first measurement point and the average electromagnetic intensity at the second measurement point during the period of injecting low-viscosity fracturing fluid to form a fracture, to obtain a gradient diffusion characteristic difference value;

[0087] The first measurement point, the second measurement point, and the ground location point are located on the same straight line, and the first reference distance is smaller than the second reference distance.

[0088] It can be understood that the gradient diffusion characteristic difference value is always a positive number.

[0089] The first reference distance is selected within the interval [1m, 5m], and the second reference distance is selected within the interval (5m, 10m].

[0090] Specifically, the diffusion characterization parameters for temporary plugging fracturing are calculated according to formula (2):

[0091]

[0092] In formula (2), X represents the diffusion characterization parameter, Y represents the gradient diffusion characteristic difference value, Y0 represents the reference gradient diffusion characteristic difference value, Z represents the diffusion range, Z0 represents the reference diffusion range, α represents the gradient diffusion characteristic difference value influence coefficient, and β represents the diffusion range influence coefficient.

[0093] The benchmark gradient diffusion characteristic difference value is obtained by pre-calculation, wherein the gradient diffusion characteristic difference values ​​during several temporary plugging and fracturing processes can be recorded in advance, and the average gradient diffusion characteristic difference value △D is solved, and D0 is set to be g×△D, where g is the gradient diffusion characteristic difference value accuracy coefficient, 1.02<g<1.12.

[0094] The benchmark diffusion range is obtained by pre-calculation. The diffusion ranges during several temporary plugging and fracturing processes can be recorded in advance, and the average diffusion range △R is solved. R0 is set to p×△N, where p is the diffusion range accuracy coefficient, 1.15<h<1.2.

[0095] In this embodiment, α is set to 0.52 and β is set to 0.48.

[0096] Specifically, the injection pressure when injecting the low-viscosity fracturing fluid is adjusted according to the diffusion characterization parameter, wherein:

[0097] If the diffusion characterization parameter is greater than the baseline diffusion characterization parameter threshold, reducing the injection pressure, optionally, the reduction amount is 0.1 to 0.3 times the initial injection pressure;

[0098] If the diffusion characterization parameter does not exceed the baseline diffusion characterization parameter threshold, the injection pressure is kept unchanged;

[0099] If the diffusion characterization parameter is less than the baseline diffusion characterization parameter threshold, the injection pressure is increased, optionally by an amount of 0.1 to 0.3 times the initial injection pressure.

[0100] Specifically, X0 represents the baseline diffusion characterization parameter, and X0 is [0.95, 1.25].

[0101] Specifically, clean water is used to wash the well until the water quality at the inlet and outlet is consistent.

[0102] It is understandable that consistent water quality at the inlet and outlet is one of the important criteria for ensuring the effectiveness of well washing. During the entire well washing process, all relevant data need to be recorded in detail, including well washing time, flow rate, water quality parameters, etc., for subsequent analysis and reference.

[0103] Specifically, the process also includes step S5, where after all the construction is completed, the well is shut down for pressure diffusion.

[0104] Specifically, after shutting in the well, the well is sealed, the pressure is diffused, the well is opened, the fracturing string in the well is pulled out, and the pump is lowered to start production. This is a necessary step and will not be elaborated on.

[0105] In this embodiment, it is determined that the well blocking time does not exceed 20 days, which will not be described in detail.

[0106] Thus far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present invention.

Claims

1. A fracturing process for alternating temporary plugging and energy enhancement in tight oil horizontal well fractures, characterized in that: include: Step S1, performing well logging on a tight oil horizontal well, wherein the well logging includes obtaining the oil layer thickness, porosity, and horizontal well length; Step S2, performing energy-enhanced fracturing on the construction section of the tight oil horizontal well, including perforating the construction section, injecting carbon dioxide and low-viscosity fracturing fluid to form fractures, and injecting high-viscosity fracturing fluid carrying proppant into the fractures to complete the energy-enhanced fracturing; The injection amount of carbon dioxide is determined based on the thickness, porosity and length of the oil layer; Step S3, determining the diffusion range by measuring the change of electromagnetic intensity at different positions on the surface of the construction section during the energy-boosting fracturing process, so as to determine the construction distance relative to the construction section, and performing temporary plugging and fracturing on the construction section, including: The construction section is perforated, low-viscosity fracturing fluid is injected to form fractures, high-viscosity fracturing fluid carrying proppant is injected into the fractures, and then a temporary plugging agent is injected to plug the ends of the fractures. Gradient diffusion characteristic difference values ​​and diffusion ranges are determined based on changes in electromagnetic intensity at different surface locations corresponding to the construction section to calculate diffusion characterization parameters for temporary plugging fracturing. The injection pressure when the low-viscosity fracturing fluid is injected again is adjusted based on the diffusion characterization parameters. After the low-viscosity fracturing fluid is injected to open branch fractures at the corresponding injection pressure, high-viscosity fracturing fluid is injected to carry proppant into the branch fractures to complete temporary plugging fracturing. Step S4, repeating steps S2 and S3 until all construction sections cover the tight oil horizontal well.

2. The fracturing process of alternating temporary plugging and energy enhancement in tight oil horizontal well fractures according to claim 1, characterized in that: In step S2, the injection amount of carbon dioxide is calculated according to formula (1): In formula (1), M represents the injection amount of carbon dioxide, represents porosity, P v represents the injection volume empirical coefficient, A represents the oil layer thickness, B represents the control radius, H represents the horizontal well length, S represents the conversion coefficient between the mass of liquid carbon dioxide and gaseous carbon dioxide at formation temperature and pressure, and n represents the length correlation coefficient.

3. The fracturing process of alternating temporary plugging and energy enhancement in tight oil horizontal well fractures according to claim 2, characterized in that: In step S2, the length correlation coefficient n is a variable parameter, and n is positively correlated with the length of the horizontal well.

4. The fracturing process of alternating temporary plugging and energy enhancement in tight oil horizontal well fractures according to claim 1, characterized in that: In step S3, the diffusion range is determined according to the change of electromagnetic intensity at different locations on the surface of the construction section during the energized fracturing process, including: Determine the ground location point corresponding to the perforation point, Determine the farthest point where the electromagnetic intensity can be measured to meet the change conditions as the diffusion point; Determining a distance between the ground location point and the diffusion point, and determining the distance as a diffusion range; The change condition includes that the change amplitude of the electromagnetic intensity is greater than a predetermined change amplitude threshold value.

5. The fracturing process of alternating temporary plugging and energy enhancement in tight oil horizontal well fractures according to claim 1, characterized in that: In step S3, the construction distance is determined based on the diffusion range, wherein: The construction distance is positively correlated with the diffusion range.

6. The fracturing process of alternating temporary plugging and energy enhancement in tight oil horizontal well fractures according to claim 4, characterized in that: In step S3, the gradient diffusion characteristic difference value is determined according to the change of electromagnetic intensity at different locations on the surface corresponding to the construction section. include, Determine the ground location point corresponding to the perforation point, Determining a first measurement point at a first reference distance from the ground location point and a second measurement point at a second reference distance from the ground location point; Determining the difference between the average electromagnetic intensity at the first measurement point and the average electromagnetic intensity at the second measurement point during the period of injecting low-viscosity fracturing fluid to form a fracture, to obtain a gradient diffusion characteristic difference value; The first measurement point, the second measurement point, and the ground location point are located on the same straight line, and the first reference distance is smaller than the second reference distance.

7. The fracturing process for alternating temporary plugging and energy enhancement in tight oil horizontal well fractures according to claim 6, characterized in that: In step S3, the diffusion characterization parameter of temporary plugging fracturing is calculated according to formula (2): In formula (2), X represents the diffusion characterization parameter, Y represents the gradient diffusion characteristic difference value, Y0 represents the reference gradient diffusion characteristic difference value, Z represents the diffusion range, Z0 represents the reference diffusion range, α represents the gradient diffusion characteristic difference value influence coefficient, and β represents the diffusion range influence coefficient.

8. The fracturing process for alternating temporary plugging and energy enhancement in tight oil horizontal well fractures according to claim 1, characterized in that: In step S3, the injection pressure of the low-viscosity fracturing fluid is adjusted according to the diffusion characterization parameter, wherein: If the diffusion characterization parameter is greater than the baseline diffusion characterization parameter threshold, reducing the injection pressure; If the diffusion characterization parameter does not exceed the baseline diffusion characterization parameter threshold, the injection pressure is kept unchanged; If the diffusion characterization parameter is less than the baseline diffusion characterization parameter threshold, increase the injection pressure.

9. The fracturing process for alternating temporary plugging and energy enhancement in tight oil horizontal well fractures according to claim 1, characterized in that: In step S1, the well needs to be washed with clean water until the water quality at the inlet and outlet of the tight oil horizontal well is consistent.

10. The fracturing process for alternating temporary plugging and energy enhancement in tight oil horizontal well fractures according to claim 1, characterized in that: The process also includes step S5, where after all the construction is completed, the well is shut down for pressure diffusion.

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