Single-stage multi-cluster fracturing method for ultra-deep shale gas, electronic device and medium

Abstract

The application discloses a single-stage multi-cluster fracturing method for ultra-deep shale gas, an electronic device and a medium. The method can comprise the following steps: calculating the formation fracture pressure of a horizontal section, and then calculating the inter-cluster interference stress; determining the perforation cluster position; calculating the bottom hole flowing pressure increase value, and controlling the bottom hole flowing pressure; according to the perforation cluster grouping condition, performing intra-fracture temporary plugging design and inter-fracture temporary plugging design on each group of perforation clusters in the fracturing section; and repeating the above steps to complete the reconstruction of all fracturing sections of the horizontal well. The application can increase the fracturing reconstruction volume of the ultra-deep shale gas by differentiating the perforation cluster position, batch starting and multi-cluster fracturing and the temporary plugging method, reduce the fracturing reconstruction cost, and help the ultra-deep shale gas to realize benefit development.

Description

Technical Field

[0001] This invention relates to the field of oil and gas reservoir development research technology, and more specifically, to a single-stage multi-cluster fracturing method, electronic equipment, and medium for ultra-deep shale gas. Background Technology

[0002] In recent years, significant progress has been made both domestically and internationally in drilling, completion, and fracturing technologies for deep shale gas formations. This has led to breakthroughs in exploration and reserve utilization in some areas. For example, in the Haynesville, Eagle Ford, and Canna Woodford blocks in North America, ultra-dense volumetric fracturing technology has been used for shale gas formations at depths below 4100m, achieving an average single-well EUR of 1.01×10⁸ to 1.47×10⁸ m³. 3 Commercial development has been achieved with a single well cost of less than US$12 million; the post-compression test production of wells such as Dongye Shen 2 and Dingye 7 in China has exceeded 40×10⁴ m³. 3 Good development benefits have been achieved. However, for ultra-deep shale gas formations with a vertical depth greater than 4500m, no breakthroughs have been made in volumetric fracturing technology, both domestically and internationally.

[0003] The main factors limiting the effectiveness of fracturing in ultra-deep shale gas reservoirs include: (1) the difficulty in forming complex fracture networks and the small volume of fracturing. Ultra-deep shale gas reservoirs are deep (>4500m) and have high formation fracturing pressure. Under the same well depth structure and horizontal section length, horizontal well fracturing in ultra-deep shale gas reservoirs requires higher construction pressure. Currently, 140MPa fracturing equipment usually cannot meet the construction requirements of large displacement (16-20m3 / min) in ultra-deep shale gas reservoirs; (2) ultra-deep shale reservoirs often have strong tectonic activity and high horizontal biaxial stress difference. For example, the horizontal biaxial stress difference in ultra-deep shale gas reservoirs in southeastern Sichuan, my country can reach 20MPa. Under high horizontal biaxial stress difference conditions, forming complex fracture networks requires higher net pressure, which currently cannot be met by fracturing equipment; in addition, ultra-deep shale gas reservoirs often have high temperature and high pressure formation conditions and strong rock plasticity. The above limiting conditions result in low complexity of fractures and small fracturing volume in ultra-deep shale gas reservoirs, and generally low post-fracturing production. (2) High well construction and stimulation costs. As vertical depth increases, drilling costs increase significantly. Due to the high pressure and low displacement of fracturing stimulation construction, fracturing costs increase. In order to enhance the stimulation effect, ultra-deep shale gas often adopts a single-stage low-cluster fracturing mode (single stage < 3 clusters), which will inevitably increase the number of stimulation stages per well, thus further increasing the fracturing stimulation cost.

[0004] Therefore, to achieve efficient development of ultra-deep shale gas, breakthroughs are needed in both creating complex fractures and reducing costs. Based on the experience of developing shallow and medium-depth shale gas, single-stage multi-cluster fracturing can effectively reduce the stimulation cost. In addition, by increasing the number of fracturing clusters and the controlled area of ​​the fracturing fractures, the simple fracture morphology can be compensated to some extent. However, there are many problems with the single-stage multi-cluster fracturing mode in ultra-deep shale gas reservoirs: (1) Inter-stage interference causes multi-cluster fractures to not initiate evenly. Due to the high initiation pressure of ultra-deep shale, once the dominant cluster initiates fracture, other clusters will find it difficult to initiate fractures or their expansion will be restricted. (2) Single-stage multi-cluster fracturing is not conducive to proppant addition. Under multi-cluster conditions, the liquid inflow of a single cluster decreases, the fracture width narrows, and the difficulty of proppant addition increases, which is not conducive to improving the long-term conductivity of the fractures. The above limitations make it common for ultra-deep shale gas fracturing stimulation to adopt a single-stage few-cluster fracturing mode.

[0005] Therefore, it is necessary to develop a single-stage multi-cluster fracturing method, electronic equipment, and media for ultra-deep shale gas.

[0006] The information disclosed in the background section of this invention is intended only to enhance the understanding of the general background of this invention, and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art. Summary of the Invention

[0007] This invention proposes a single-stage multi-cluster fracturing method, electronic equipment, and medium for ultra-deep shale gas. It can increase the fracturing volume of ultra-deep shale gas by differentially determining the location of perforation clusters, initiating multi-cluster fractures in batches, and using temporary plugging methods, while reducing the cost of fracturing and stimulation, thus helping to achieve profitable development of ultra-deep shale gas.

[0008] In a first aspect, embodiments of this disclosure provide a method for single-stage multi-cluster fracturing of ultra-deep shale gas, including:

[0009] Calculate the formation fracture pressure in the horizontal section, and then calculate the inter-cluster interference stress;

[0010] Determine the location of the perforation cluster;

[0011] Calculate the increase in bottom hole flowing pressure and control the bottom hole flowing pressure;

[0012] Based on the grouping of perforation clusters, temporary plugging designs within and between perforation clusters are implemented for each group within the fracturing section.

[0013] Repeat the above steps to complete the fracturing of all fracturing sections in the horizontal well.

[0014] Preferably, determining the location of the perforation cluster includes:

[0015] The location of perforation clusters is selected based on the formation fracture pressure profile of the horizontal wellbore, with 1 to 2 clusters as a group, and each segment is divided into 3 to 4 groups of perforation clusters.

[0016] The spacing between each cluster is adjusted according to the inter-cluster interference stress, so that the difference between the rupture pressure and the sum of the inter-cluster interference stress of each group of perforation clusters is less than a set threshold, and the difference between the rupture pressure and the sum of the inter-cluster interference stress of different groups of perforation clusters is greater than the set threshold.

[0017] Preferably, the set threshold is 3 MPa.

[0018] Preferably, the increase in bottom hole flowing pressure is:

[0019] △P 流压 =△P 井口 -△P 井筒 -△P 孔眼 -△P 缝内

[0020] Among them, △P 井筒 P represents the change in wellbore friction. 井筒 =1.385×10 6 *d 4.8 *L*Q 1.8 *α, d, L, Q, and α represent the wellbore diameter, wellbore length, fracturing fluid displacement, and fracturing fluid drag reduction rate, respectively. △P 孔眼 P represents the change in the frictional resistance of the orifice. 孔眼 =a2*Q 2 a2 is a fixed constant, ΔP 缝内 P represents the change in flow resistance within the gap. 缝内 =a3*β*Q 2 a3 is a fixed constant, and β is the filtration correlation coefficient.

[0021] Preferably, the temporary plugging design within the joint includes:

[0022] Based on the grouping of perforation clusters, a pumping procedure was designed for the first group of perforation clusters. By adjusting the sand ratio and liquid viscosity, a temporary plugging design was achieved within the perforation.

[0023] Preferably, the diameter of the temporary plugging ball is 1.5 times the diameter of the perforation hole.

[0024] Preferably, the inter-gap temporary plugging design includes:

[0025] The number of inter-slit temporary plugging balls is determined based on the number of perforations in the first group of perforations, thus realizing the inter-slit temporary plugging design.

[0026] Preferably, the last group of perforations in the fracturing section does not require intra-fracturing temporary plugging design or inter-fracturing temporary plugging design.

[0027] Secondly, embodiments of this disclosure also provide an electronic device, the electronic device comprising:

[0028] Memory, which stores executable instructions;

[0029] A processor that executes the executable instructions in the memory to implement the single-stage multi-cluster fracturing method for ultra-deep shale gas.

[0030] Thirdly, this disclosure also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the described single-stage multi-cluster fracturing method for ultra-deep shale gas.

[0031] The methods and apparatus of the present invention have other features and advantages that will be apparent from or will be set forth in detail in the accompanying drawings and following detailed description, which together serve to explain the particular principles of the invention. Attached Figure Description

[0032] The above and other objects, features and advantages of the present invention will become more apparent from the more detailed description of exemplary embodiments of the invention in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same parts.

[0033] Figure 1 A flowchart illustrating the steps of a single-stage multi-cluster fracturing method for ultra-deep shale gas according to an embodiment of the present invention is shown. Detailed Implementation

[0034] Preferred embodiments of the invention will now be described in more detail. While preferred embodiments of the invention are described below, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0035] This invention provides a method for single-stage multi-cluster fracturing of ultra-deep shale gas formations, comprising:

[0036] Calculate the formation fracture pressure in the horizontal section, and then calculate the inter-cluster interference stress;

[0037] Determine the location of the perforation cluster;

[0038] Calculate the increase in bottom hole flowing pressure and control the bottom hole flowing pressure;

[0039] Based on the grouping of perforation clusters, temporary plugging designs within and between perforation clusters are implemented for each group within the fracturing section.

[0040] Repeat the above steps to complete the fracturing of all fracturing sections in the horizontal well.

[0041] In one example, determining the location of the perforation cluster includes:

[0042] The location of perforation clusters is selected based on the formation fracture pressure profile of the horizontal wellbore, with 1 to 2 clusters as a group, and each segment is divided into 3 to 4 groups of perforation clusters.

[0043] The spacing between each cluster is adjusted according to the inter-cluster interference stress, so that the difference between the rupture pressure of each group of perforation clusters and the sum of the inter-cluster interference stress is less than a set threshold, and the difference between the rupture pressure of different groups of perforation clusters and the sum of the inter-cluster interference stress is greater than the set threshold.

[0044] In one example, the threshold is set to 3 MPa.

[0045] In one example, the increase in bottom hole flowing pressure is:

[0046] △P 流压 =△P 井口 -△P 井筒 -△P 孔眼 -△P 缝内

[0047] Among them, △P 井筒 P represents the change in wellbore friction. 井筒 =1.385×10 6 *d 4.8 *L*Q 1.8 *α, d, L, Q, and α represent the wellbore diameter, wellbore length, fracturing fluid displacement, and fracturing fluid drag reduction rate, respectively. △P 孔眼 P represents the change in the frictional resistance of the orifice. 孔眼 =a2*Q 2 a2 is a fixed constant, ΔP 缝内 P represents the change in flow resistance within the gap. 缝内 =a3*β*Q 2 a3 is a fixed constant, and β is the filtration correlation coefficient.

[0048] In one example, the intra-suture temporary plugging design includes:

[0049] Based on the grouping of perforation clusters, a pumping procedure was designed for the first group of perforation clusters. By adjusting the sand ratio and liquid viscosity, a temporary plugging design was achieved within the perforation.

[0050] In one example, the diameter of the temporary plugging ball is 1.5 times the diameter of the perforation orifice.

[0051] In one example, the interstitial plugging design includes:

[0052] The number of inter-slit temporary plugging balls is determined based on the number of perforations in the first group of perforations, thus realizing the inter-slit temporary plugging design.

[0053] In one example, the last group of perforations within the fracturing section does not require intra-fracturing temporary plugging design or inter-fracturing temporary plugging design.

[0054] Specifically, this invention utilizes differentiated perforation cluster division to fully leverage inter-cluster interference stress. Combined with operational parameters such as flow rate and fracturing fluid viscosity, it precisely controls the slow, step-like increase of bottomhole flowing pressure, thereby enabling the phased initiation and filling of multiple fracture clusters. Subsequently, through temporary plugging and other measures, it achieves balanced transformation of all clusters. The core of this invention lies in the method for selecting perforation cluster locations, the method for controlling bottomhole flowing pressure, and the method for achieving efficient temporary plugging.

[0055] (1) Differentiated determination of perforation cluster location: Typically, deep / ultra-deep shale gas fracturing involves 2-4 clusters per segment. During the fracture creation stage, all 2-4 clusters of fractures are initiated using a gel (or ultra-high viscosity slickwater) and rapid flow rate increase. In the method of this invention, 6-8 clusters are per segment. By selecting sweet spot locations and considering inter-cluster interference, 1-3 clusters of fractures are grouped together, ensuring that clusters within the same group have similar initiation pressures (<0-3MPa), while different groups have significantly different initiation pressures (>3MPa).

[0056] (2) Batch fracturing and fracture filling: The key to achieving batch fracturing of multiple clusters of fractures is to accurately control the bottom hole pressure, gradually increasing it step by step. If the bottom hole pressure rises too quickly, multiple perforation clusters will fracture simultaneously, resulting in numerous simultaneous fluid inlets, poor energy concentration, and difficulty in adding sand. Simultaneously, if the bottom hole pressure gradually increases, even perforation clusters within the same group will compete for fracturing. Once a perforation cluster fractures first, it will inhibit the fracturing of other perforation clusters in the same group, failing to achieve the effect of simultaneously fracturing a group of perforation clusters. First, by pumping gel, the flow rate is gradually increased step by step until the bottom hole pressure exceeds the fracturing pressure of all clusters in the first group. After the first group of fractures fractures, it inhibits the fracturing of other clusters, thus allowing the bottom hole pressure to be increased by another 2-3 MPa without causing other clusters to fracture. A pumping procedure is designed with the goal of single-group fracturing, and sand is added. Subsequently, near-wellbore fracture channels are sealed with a high-concentration temporary plugging agent. Then, the fluid inlet channels of the opened perforated clusters are sealed using a temporary plugging ball. It is calculated that 50%–75% of the fluid inlet channels are sealed to control the generation of a 3–5 MPa activation pressure within the wellbore at the moment of plugging, thus initiating the fracturing of the next set of fractures. Six to eight fracturing clusters are completed using the above method.

[0057] The specific implementation steps of this method are as follows:

[0058] 1) Calculate the fracture pressure in the horizontal section of the formation.

[0059] Based on well logging, well logging and rock mechanics experimental data, the formation fracture pressure profile of the horizontal wellbore section was calculated.

[0060] 2) Calculate inter-cluster interference stress

[0061] Based on reservoir rock characteristics and construction conditions, the inter-cluster interference stress at different cluster spacings was calculated.

[0062] 3) Select the location of the perforation cluster

[0063] Based on the formation fracture pressure profile of the horizontal wellbore, the location of perforation clusters is selected, with 1-2 clusters per group. Within the same group, the fracture pressure of the perforation clusters is similar. Each segment is divided into 3-4 groups of perforation clusters. Then, the spacing between each cluster is adjusted according to the inter-cluster interference stress to make the sum of the fracture pressure and inter-cluster interference stress of each group of perforation clusters as similar as possible (<3MPa), and to ensure that the fracture pressure and the sum of the inter-cluster interference stress of different groups of perforation clusters have significant differences (>3MPa).

[0064] 4) Calculate the bottom hole flowing pressure

[0065] The increase in wellhead pressure during fracturing is:

[0066] △P 井口 =△P 井筒 +△P 孔眼 +△P 缝内 +△P 流压

[0067] Among them, △P 井筒 P represents the change in wellbore friction. 井筒 =1.385×10 6 *d 4.8 *L*Q 1.8 *α, d, L, Q, and α represent the wellbore diameter, wellbore length, fracturing flow rate, and fracturing fluid drag reduction rate, respectively. For a fixed perforation cluster, d and L are constants; therefore, P 井筒 =a1*Q 1.8 *α, a1 are fixed constants; △P 孔眼 This represents the change in the frictional resistance of the orifice; similarly, P... 孔眼 =a2*Q 2 a2 is a fixed constant; ΔP 缝内 P represents the change in flow resistance within the gap. 缝内 =a3*β*Q 2 a3 is a fixed constant, β is the filtration correlation coefficient; ΔP 流压 This represents the increase in bottom hole flowing pressure.

[0068] 5) Bottom hole flowing pressure control strategy

[0069] According to the bottom hole flowing pressure calculation formula in step 4), α and β are related to the properties of the fracturing fluid. Therefore, by controlling the discharge rate and fluid properties, the bottom hole flowing pressure can be precisely controlled, so that the single step increase of the bottom hole flowing pressure is controlled within 3MPa.

[0070] 6) Design the pumping procedure

[0071] Based on the grouping of perforation clusters, a pumping procedure was designed for the first group of perforation clusters to meet the requirements for discharge rate, liquid volume, and sand addition.

[0072] 7) Design temporary plugs inside the joint

[0073] In the later stage of the first group of perforation cluster modification, the sand ratio and liquid viscosity were adjusted to achieve end sand removal, while a high concentration of temporary plugging agent was applied to the tail to increase the flow resistance of the fracturing fluid in the fracture.

[0074] 8) Design temporary plugs for joints

[0075] The number of temporary plugging balls is determined based on the number of perforations in the first group of perforations. The diameter of the temporary plugging balls is 1.5 times the diameter of the perforations. The plugging efficiency of the temporary plugging balls is calculated as 75%. The goal is to control 50% to 75% of the perforations in the first group of perforations to be plugged. The specific number of plugged perforations depends on the temporary plugging efficiency in step 7). If the flow resistance in the gap increases significantly after the temporary plugging agent in step 7), the number of temporary plugging balls in step 8) should be appropriately reduced.

[0076] 9) Use microseismic monitoring to monitor crack propagation.

[0077] 10) Repeat steps 4)-9) to complete the fracturing and sand addition of the remaining perforation clusters. Since the fracturing of this section will be completed after the last perforation cluster is finished, no temporary plugging is required in or between the fractures during the pumping of the last perforation cluster.

[0078] 11) Repeat steps 1)-10) to complete the fracturing of all fracturing sections in the horizontal well.

[0079] 12) Use production and diaphragm technology to test the post-compression gas production effect.

[0080] The present invention also provides an electronic device, comprising: a memory storing executable instructions; and a processor executing the executable instructions in the memory to implement the above-described single-stage multi-cluster fracturing method for ultra-deep shale gas.

[0081] The present invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described single-stage multi-cluster fracturing method for ultra-deep shale gas.

[0082] To facilitate understanding of the solutions and effects of the embodiments of the present invention, three specific application examples are given below. Those skilled in the art should understand that these examples are merely for the purpose of understanding the present invention, and any specific details therein are not intended to limit the present invention in any way.

[0083] Example 1

[0084] Figure 1A flowchart illustrating the steps of a single-stage multi-cluster fracturing method for ultra-deep shale gas according to an embodiment of the present invention is shown.

[0085] like Figure 1 As shown, the single-stage multi-cluster fracturing method for ultra-deep shale gas includes: Step 101, calculating the formation fracturing pressure in the horizontal section, and then calculating the inter-cluster interference stress; Step 102, determining the location of the perforation clusters; Step 103, calculating the bottom hole flowing pressure increase and controlling the bottom hole flowing pressure; Step 104, according to the perforation cluster grouping, designing intra-fracture temporary plugging and inter-fracture temporary plugging for each group of perforation clusters in the fracturing section; Step 105, repeating the above steps to complete the fracturing of all sections of the horizontal well.

[0086] A certain ultra-deep shale gas horizontal well X has a reservoir vertical depth of 4800m, a thickness of 30m, a Young's modulus of 40GPa, a Poisson's ratio of 0.2, a biaxial horizontal stress difference of 20MPa, and a horizontal section length of 1500m. Volumetric fracturing stimulation is performed using the ultra-deep shale gas single-stage multi-cluster fracturing method provided in this patent. The specific implementation steps are as follows:

[0087] 1) Based on well logging interpretation data and core mechanics data, the formation fracture pressure in the horizontal section is calculated to be 121-129 MPa, with relatively large differences in formation fracture pressure in the horizontal section.

[0088] 2) Based on the brittle characteristics of the formation, the inter-cluster interference stress is calculated to be 6.2-0.6 MPa when the cluster spacing is 6-15 m and the fracture width (fracture opening) is 1 cm.

[0089] 3) Based on the differences in formation in the horizontal section and the perforation cluster selection method of the present invention, the first fracturing section is divided into 6 clusters, with 2 clusters forming a group, an average cluster spacing of 9.6m, a section length of 70m, and 6 perforations per cluster with a diameter of 12mm.

[0090] 4) Based on the bottom hole flowing pressure calculation, the fracturing fluid drag reducer concentration is 0.8% and the flow rate is 6.5 m³ / h. 3 At a flow rate of 124 MPa at the bottom hole, the first group of perforations can be fully fractured. After fracture initiation, the flow rate will be increased to 8 m³ / min. 3 / min.

[0091] 5) The pumping procedure is designed according to two clusters, with a single cluster liquid volume of 1000m³. 3 Sand volume 50m 3 .

[0092] 6) In the later stage of fracturing of the first group of perforation clusters, use 30 / 50 mesh proppant and 20% sand ratio to remove sand from the ends, and then quickly inject 200 kg of temporary plugging agent.

[0093] 7) Based on the changes in bottom hole flowing pressure, deploy 15 18mm temporary plugging balls.

[0094] 8) Repeat steps 4)-7) to complete the fracturing of the second and third groups of perforation clusters in the first segment.

[0095] 9) Repeat steps 2)-8) to complete the fracturing of the entire well from the 2nd to the 20th stage.

[0096] 10) Microseismic monitoring and profiling tests showed that the fractures in multiple clusters were well-initiated and propagated in a balanced manner, and the gas production contribution rate of each cluster was relatively balanced.

[0097] Example 2

[0098] This disclosure provides an electronic device comprising: a memory storing executable instructions; and a processor executing the executable instructions in the memory to implement the aforementioned single-stage multi-cluster fracturing method for ultra-deep shale gas.

[0099] An electronic device according to an embodiment of the present disclosure includes a memory and a processor.

[0100] This memory is used to store non-transitory computer-readable instructions. Specifically, the memory may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may, for example, include random access memory (RAM) and / or cache memory. The non-volatile memory may, for example, include read-only memory (ROM), hard disk, flash memory, etc.

[0101] The processor may be a central processing unit (CPU) or other form of processing unit with data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions. In one embodiment of this disclosure, the processor is used to execute computer-readable instructions stored in the memory.

[0102] Those skilled in the art will understand that, in order to solve the technical problem of how to achieve a good user experience, this embodiment may also include well-known structures such as communication buses and interfaces, and these well-known structures should also be included within the protection scope of this disclosure.

[0103] For a detailed description of this embodiment, please refer to the corresponding descriptions in the foregoing embodiments, which will not be repeated here.

[0104] Example 3

[0105] This disclosure provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the described single-stage multi-cluster fracturing method for ultra-deep shale gas.

[0106] A computer-readable storage medium according to embodiments of the present disclosure stores non-transitory computer-readable instructions. When these non-transitory computer-readable instructions are executed by a processor, all or part of the steps of the methods described in the foregoing embodiments of the present disclosure are performed.

[0107] The aforementioned computer-readable storage media include, but are not limited to: optical storage media (e.g., CD-ROM and DVD), magneto-optical storage media (e.g., MO), magnetic storage media (e.g., magnetic tape or portable hard drive), media with built-in rewritable non-volatile memory (e.g., memory card), and media with built-in ROM (e.g., ROM cartridge).

[0108] Those skilled in the art should understand that the above description of the embodiments of the present invention is only intended to illustrate the beneficial effects of the embodiments of the present invention, and is not intended to limit the embodiments of the present invention to any of the examples given.

[0109] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A method for single-stage multi-cluster fracturing of ultra-deep shale gas formations, characterized in that, include: Calculate the formation fracture pressure in the horizontal section, and then calculate the inter-cluster interference stress; Determine the location of the perforation cluster; Calculate the increase in bottom hole flowing pressure and control the bottom hole flowing pressure; Based on the grouping of perforation clusters, temporary plugging designs within and between perforation clusters are implemented for each group within the fracturing section. Repeat the above steps to complete the fracturing of all sections of the horizontal well; Determining the location of the perforation cluster includes: Select the location of perforation clusters based on the formation fracture pressure profile of the horizontal wellbore, grouping them into sets of 1-2 clusters, and dividing each segment into 3-4 groups of perforation clusters; The spacing between each cluster is adjusted according to the inter-cluster interference stress so that the difference between the rupture pressure and the sum of the inter-cluster interference stress of each group of perforation clusters is less than a set threshold, and the difference between the rupture pressure and the sum of the inter-cluster interference stress of different groups of perforation clusters is greater than the set threshold. The set threshold is 3 MPa; The temporary plugging design within the joint includes: Based on the grouping of perforation clusters, a pumping procedure was designed for the first group of perforation clusters. By adjusting the sand ratio and liquid viscosity, a temporary plugging design was achieved within the crack. The inter-gap temporary plugging design includes: The number of inter-slit temporary plugging balls is determined based on the number of perforations in the first group of perforations, thus realizing the inter-slit temporary plugging design.

2. The single-stage multi-cluster fracturing method for ultra-deep shale gas as described in claim 1, wherein, The increase in bottom hole flowing pressure is: △P 流压 =△P 井口 -△P 井筒 -△P 孔眼 -△P 缝内 Among them, △P 井筒 P represents the change in wellbore friction. 井筒 =1.385×10 6 d 4.8 L Q 1.8 α, d, L, Q, and α represent the wellbore diameter, wellbore length, fracturing flow rate, and fracturing fluid drag reduction rate, respectively, and ΔP 孔眼 P represents the change in the frictional resistance of the orifice. 孔眼 =a2 Q 2 a2 is a fixed constant, ΔP 缝内 P represents the change in flow resistance within the gap. 缝内 =a3 β Q 2 a3 is a fixed constant, and β is the filtration correlation coefficient.

3. The single-stage multi-cluster fracturing method for ultra-deep shale gas as described in claim 1, wherein, The diameter of the temporary plugging ball is 1.5 times the diameter of the perforation hole.

4. The single-stage multi-cluster fracturing method for ultra-deep shale gas formations according to claim 1, wherein, The last group of perforations in the fracturing section does not require intra-fracturing temporary plugging design or inter-fracturing temporary plugging design.

5. An electronic device, characterized in that, The electronic device includes: Memory, which stores executable instructions; A processor that executes the executable instructions in the memory to implement the single-stage multi-cluster fracturing method for ultra-deep shale gas as described in any one of claims 1-4.

6. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the single-stage multi-cluster fracturing method for ultra-deep shale gas as described in any one of claims 1-4.

Images