Device and method for simulating multi-layer three-dimensional fracturing perforation blastholes of highly-deviated well

Abstract

The invention discloses a highly-deviated well multi-layer three-dimensional fracturing perforation shot hole simulation device and method. The simulation device comprises a fracturing fluid injection mechanism, a true triaxial hydraulic fracturing physical simulation experiment mechanism and a simulation sample. The simulation sample is arranged in a sample cavity of the true triaxial hydraulic fracturing physical simulation experiment mechanism, and the fracturing fluid injection mechanism is connected with the simulation sample; the simulation method comprises the following steps: manufacturing a simulation wellbore and a perforation module; connecting the adapter with the simulation wellbore; assembling a simulation sample; molding the simulation sample; assembling the simulation sample and a true triaxial hydrofracture physical simulation experiment mechanism; connecting a liquid injection pipeline with an injection pump; loading confining pressure; injecting fracturing fluid into the simulation sample; after the experiment is finished, the sample is moved out of the experiment cavity; and observing the simulated sample after the test. The device is reliable in structure, fine simulation of shot hole positions of highly-deviated wells with different hole deviation angles can be achieved, a new method is provided for hydraulic fracturing indoor experiment research, and the progress of multi-cluster perforation fracturing experiments towards the fine direction is promoted.

Description

Technical Field

[0001] The invention belongs to the technical field of hydraulic fracturing construction in petroleum engineering, and in particular relates to a device and method for simulating blastholes of multi-layer three-dimensional fracturing in highly deviated wells. Background Art

[0002] my country's offshore thin interbedded reservoirs hold enormous potential for development. However, due to the high input-output ratio, conventional development methods for these reservoirs often struggle to achieve high economic returns. To improve the effective utilization and development of these reservoirs and enhance effective well control and cumulative production in individual wells, a design aims to expand the unloading range of highly deviated wells by fracturing them through perforated blastholes. This approach, through fracture expansion, improves the well's actual sand extraction and production capacity. The inclination and azimuth of highly deviated wells result in a more complex distribution of ground stress around the wellbore than in vertical wells, significantly increasing the difficulty of initiating fractures. Therefore, perforation technology has become a key step in the fracturing treatment of highly deviated wells. Perforated blastholes are formed within the formation rock, significantly reducing the pressure required for fracture initiation and effectively improving stress concentration near the wellbore, laying the foundation for the successful implementation of subsequent hydraulic fracturing. At the same time, multi-stage and multi-cluster perforation fracturing operations on thin interbedded oil reservoirs can effectively form translaminar fractures in the reservoir, significantly increase the reservoir drainage area, and form a large number of oil and gas migration channels with high conductivity, which not only increases the initial production but is also more conducive to long-term stable production.

[0003] With the successful application of hydraulic fracturing in the unconventional oil and gas sector and the increasing difficulty of unconventional oil and gas extraction, the need for studying multi-cluster perforation fracturing in highly deviated wells is increasing, placing higher demands on the accuracy of multi-cluster perforation fracturing physical simulation experiments. To provide a solid experimental basis and reliable technical guidance for field fracturing design and construction plans, and to explore the impact of multiple factors such as perforation density and fracture propagation mechanism on the fracturing effect during multi-cluster perforation fracturing in highly deviated wells at different angles, indoor hydraulic fracturing physical simulation experiments require simulation results of blastholes in highly deviated wells at different well inclinations. Traditional hydraulic fracturing experiments cannot provide cementing methods for highly deviated wells that simulate blastholes, making it difficult to study the impact of perforation parameters on fracture propagation morphology in highly deviated wells at different well inclinations. Summary of the Invention

[0004] The present invention is proposed to solve the problems existing in the prior art, and its purpose is to provide a device and method for simulating blastholes of multi-layer three-dimensional fracturing and perforation in highly deviated wells.

[0005] The present invention is achieved through the following technical solutions:

[0006] A multi-layer three-dimensional fracturing perforation blasthole simulation device for highly deviated wells includes a fracturing fluid injection mechanism, a true triaxial hydraulic fracturing physical simulation experimental mechanism and a simulation sample; the simulation sample is placed in a sample cavity of the true triaxial hydraulic fracturing physical simulation experimental mechanism, and the fracturing fluid injection mechanism is connected to the simulation sample.

[0007] In the above technical solution, the fracturing fluid injection mechanism includes an injection pump group, a multi-channel flow control mechanism and an adapter connected in sequence; the injection pump group includes two injection pumps, each of which is connected to a three-way valve, and the other path of the three-way valve is connected to the multi-channel flow control mechanism through a main line; the multi-channel flow control mechanism includes multiple groups of flow control units, and the flow control unit includes branch lines and solenoid valves, flow meters and pressure gauges arranged in sequence on the branch lines.

[0008] In the above technical solution, the adapter includes a coaxially connected screw lock head and a transition cavity, multiple liquid flows are formed in the screw lock head and the transition cavity, and multiple pipeline joints are arranged on the end face of the transition cavity away from one end of the screw lock head; the liquid flow channel in the screw lock head is connected to the liquid flow channel and the pipeline joint in the transition cavity in a one-to-one correspondence; the other end of the branch line is connected to the liquid flow channel in the screw lock head.

[0009] In the above technical solution, the simulated sample includes a rock sample and a simulated wellbore. The simulated wellbore is embedded in the rock sample. A wellbore packer is provided at the bottom end of the simulated wellbore. A plurality of perforating modules are provided on the simulated wellbore.

[0010] In the above technical solution, the specifications of the rock sample are 300mm×300mm×300mm, and the rock sample is an outcrop rock sample or a concrete rock sample.

[0011] In the above technical solution, the simulated wellbore consists of a vertical wellbore, a horizontal wellbore and an inclined wellbore connected in sequence; the angle between the horizontal wellbore and the inclined wellbore is adjusted according to the simulation requirements.

[0012] In the above technical solution, the perforating module is arranged on the inclined wellbore; the outer walls of both ends of the perforating module are sleeved with sealing rubber rings; the perforating module is connected to the pipeline joint through a simulated perforating pipeline; a plurality of guide grooves are provided in the simulated wellbore, and the simulated perforating pipeline is embedded in the guide grooves; the perforating module is a hollow cylindrical structure, and through holes are formed on its top and bottom surfaces. The inclined wellbore passes through the through holes on the top and bottom surfaces of the perforating module, and the perforating module is welded and fixed to the inclined wellbore; the inner diameter of the perforating module is larger than the outer diameter of the inclined wellbore; and a plurality of perforating holes are evenly distributed on the circumferential wall of the perforating module.

[0013] A simulation method for the aforementioned multi-layer three-dimensional fracturing and perforating blasthole simulation device for highly deviated wells comprises the following steps:

[0014] (I) Manufacturing simulated wellbore and perforation modules;

[0015] (II) Installing the adapter into the simulated wellbore;

[0016] (III) assembling the simulated wellbore and the rock sample to form a simulated specimen;

[0017] (IV) Simulation specimen molding;

[0018] (V) moving the simulated sample into the sample chamber of the true triaxial hydraulic fracturing physical simulation experimental system;

[0019] (VI) connecting the injection line to the fracturing fluid injection pump;

[0020] (VII) Applying three-dimensional confining pressure to the simulated specimen;

[0021] (VIII) injecting the fracturing fluid into the simulated sample;

[0022] (IX) After the experiment is completed, gradually turn off the injection pump group; after the pressure relief is completed, remove the simulated sample;

[0023] (Ⅹ) The removed specimen is mechanically cut or dissected to observe the morphology of the crack network inside the specimen.

[0024] In the above technical solution, the step (III) is specifically as follows:

[0025] When concrete rock samples are used as rock specimens, the simulated specimens are prepared as follows: a simulated wellbore with the adapter, perforating module, and simulated perforating pipeline installed is placed in the center of a cement mold. Subsequently, cement slurry is evenly injected into the mold until the specimen reaches a size of 300 mm × 300 mm × 300 mm.

[0026] When the rock sample is an outcrop rock sample or a downhole core, a wellbore is first drilled on the rock sample, and then the simulated wellbore is placed in the wellbore.

[0027] In the above technical solution, the step (IV) of simulating sample forming is specifically as follows:

[0028] When concrete rock samples are used as rock samples, the samples are left to stand and wait for the cement to completely solidify and wrap around the wellbore and perforation module;

[0029] When the rock sample is an outcrop rock sample or a downhole core, the annulus between the rock sample and the simulated wellbore is cemented with glue;

[0030] When the rock sample is an outcrop rock sample or downhole core and the size is less than 300×300mm, it is wrapped with concrete to achieve the target size.

[0031] The beneficial effects of the present invention are:

[0032] The present invention provides a device and method for simulating the initiation and expansion of fractures in a stratum containing perforated blastholes during three-dimensional fracturing of multiple layers in a highly deviated well, which can simulate the blasthole positions of the highly deviated well and conduct fracturing experiments in highly deviated wells with different well inclination angles.

[0033] The present invention can simulate highly deviated wells and variable angle working conditions. Through the design of the adjustable inclined tube in the device, the wellbore angle can be flexibly adjusted, and it can be adapted within the range of 90° to 180°, accurately simulating the perforation and fracturing operations of highly deviated wells and working conditions with different inclination angles, and meeting the experimental requirements of complex wellbore conditions; the present invention can realize the quantitative research of indoor physical simulation experiments such as natural flow distribution, constant flow distribution, temporary plugging of seams, and multi-layer three-dimensional fracturing, and promote the development of indoor hydraulic fracturing simulation experiments in the direction of refinement and quantification; the perforation method of the present invention is modularized, and the perforation of the same height layer and the spiral perforation can be switched by replacing the perforation module, and the perforation scheme under the dense cutting fracturing scheme can be optimized; the present invention provides an experimental basis for the three-dimensional development and construction plan of highly deviated wells by designing and processing simulated wellbores of highly deviated wells with different inclination angles, combining cement wrapping and crack observation technology, and can further optimize the segmented cluster fracturing parameters and the multi-layer three-dimensional well network layout plan. The present invention provides an innovative method for indoor experimental research on multi-layer three-dimensional fracturing in highly deviated wells, promotes the development of indoor hydraulic fracturing simulation technology towards refinement, quantification and adaptability to multiple working conditions, and has important engineering value and scientific research significance.

[0034] The present invention has no special requirements for the material of the experimental samples, only requiring that the samples meet the dimensions specified by the indoor true triaxial hydraulic fracturing device; when full-diameter downhole cores or field outcrops are unavailable, cement samples with properties similar to those of the reservoir can be used to carry out experiments.

[0035] The present invention has a reasonable design structure and can simulate hydraulic fracturing under the fracturing construction parameters of most thin interbedded reservoirs in China; it has a significant promoting effect on clarifying the influence of perforation patterns and different well inclination angles on crack propagation behavior during multi-cluster fracturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a structural schematic diagram of the fracturing fluid injection mechanism of the present invention;

[0037] Figure 2 It is a structural diagram of the transfer joint of the present invention;

[0038] Figure 3 It is a schematic diagram of the assembly structure of the true triaxial hydraulic fracturing physical simulation experimental mechanism and the simulation specimen in the present invention;

[0039] Figure 4 This is a schematic diagram of the assembly structure of the simulated wellbore and the adapter in the present invention;

[0040] Figure 5 It is a schematic diagram of the assembly structure of the simulated wellbore and the simulated perforating pipeline in the present invention;

[0041] Figure 6 It is a structural schematic diagram of the perforating module in the present invention;

[0042] Figure 7 yes Figure 6 Middle AA section view.

[0043] in:

[0044] 1. Fracturing fluid injection mechanism; 11. Injection pump assembly; 12. Multi-channel flow control mechanism; 13. Adapter; 111. Injection pump; 112. Three-way valve; 121. Solenoid valve; 122. Flow meter; 123. Pressure gauge; 131. Screw lock; 132. Transition chamber; 133. Pipeline connector;

[0045] 2. True triaxial hydraulic fracturing physical simulation experimental institution;

[0046] 3. Simulated specimen; 31. Rock specimen; 32. Simulated wellbore; 321. Vertical wellbore; 322. Horizontal wellbore; 323. Inclined wellbore;

[0047] 33. Perforating module; 331. Perforating blasthole; 34. Sealing rubber ring; 35. Simulated perforating pipeline; 36. Anti-skid column.

[0048] For ordinary technicians in this field, other relevant drawings can be obtained based on the above drawings without any creative work. DETAILED DESCRIPTION

[0049] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0050] Example 1

[0051] like Figures 1 to 7 As shown, a multi-layer three-dimensional fracturing perforation blasthole simulation device for highly deviated wells includes a fracturing fluid injection mechanism 1, a true triaxial hydraulic fracturing physical simulation experimental mechanism 2, and a simulation sample 3; the simulation sample 3 is placed in the sample cavity of the true triaxial hydraulic fracturing physical simulation experimental mechanism 2, and the fracturing fluid injection mechanism 1 is connected to the simulation sample 3;

[0052] The fracturing fluid injection mechanism 1 comprises an injection pump group 11, a multi-channel flow control mechanism 12 and an adapter 13 connected in sequence;

[0053] The injection pump group 11 includes two injection pumps 111 connected to a three-way valve 112, and the other end of the three-way valve 112 is connected to the multi-channel flow control mechanism 12 through a main line;

[0054] The multi-channel flow control mechanism 12 includes multiple flow control units, each of which includes a branch line and a solenoid valve 121, a flow meter 122, and a pressure gauge 123 sequentially arranged on the branch line.

[0055] The adapter 13 includes a coaxially connected screw lock head 131 and a transition cavity 132. Multiple liquid channels are formed in the screw lock head 131 and the transition cavity 132. A plurality of pipeline connectors 133 are provided on the end surface of the transition cavity 132 away from the screw lock head. The liquid flow channel in the screw lock head 131 is connected to the liquid flow channel in the transition cavity 132 and the pipeline connectors 133 in a one-to-one correspondence. The other end of the branch line is connected to the liquid flow channel in the screw lock head 131.

[0056] The fracturing fluid injection mechanism 1 delivers the fracturing fluid to an independent perforating module through the main pipeline and branch pipelines, thus realizing independent fluid supply to each perforating cluster;

[0057] The true triaxial hydraulic fracturing physical simulation experimental device 2 adopts the indoor experimental device based on true triaxial acid fracturing disclosed in the patent with publication number CN 110439544A and patent name "An indoor experimental device based on true triaxial acid fracturing and acid fracturing simulation method";

[0058] The simulated sample 3 includes a rock sample 31 and a simulated wellbore 32. The simulated wellbore 32 is embedded in the rock sample 31. A wellbore packer 34 is provided at the bottom of the simulated wellbore 32. A plurality of perforation modules 33 are provided on the simulated wellbore 32.

[0059] The rock sample 31 has a size of 300 mm × 300 mm × 300 mm. The rock sample 31 is mainly an outcrop rock sample, and may also be combined with a concrete rock sample or other artificial rock sample.

[0060] The simulated wellbore 32 consists of a vertical wellbore 321, a horizontal wellbore 322, and an inclined wellbore 323 connected in sequence. The angle between the horizontal wellbore 322 and the inclined wellbore 323 can be adjusted according to the actual simulation experiment requirements, and can simulate highly deviated wells with different well inclination angles, thereby meeting the needs of wellbore simulation at different angles and studying the influence of well inclination angle on the direction and morphology of fracture propagation. The horizontal wellbore 322 and the inclined wellbore 323 are connected at a determined angle during the wellbore processing step. The adjustment of the wellbore inclination angle according to requirements enables the device to meet the experimental requirements of various well types and enhances the adaptability of the experiment.

[0061] The upper end of the inclined wellbore 323 is provided with a plurality of anti-skid columns 36, which are used to increase the contact area between the wellbore and the glue to prevent it from being pulled out; the anti-skid columns 36 are arranged above the perforating module 33;

[0062] The perforating modules 33 are arranged on the inclined wellbore 323; the outer walls of both ends of each perforating module 33 are sleeved with isolation rubber rings 34; the isolation rubber rings 34 can achieve layer isolation and fluid control by forming an effective seal between the wellbore or different formations, preventing interlayer flow and guiding the fluid to flow along a predetermined path;

[0063] The perforating module 33 is connected to the pipeline joint 133 through the simulated perforating pipeline 35; a plurality of guide grooves are provided in the simulated wellbore 32, and the simulated perforating pipeline 35 is embedded in the guide grooves;

[0064] The perforating module 33 is a hollow cylindrical structure with through holes formed on its top and bottom surfaces. The inclined wellbore 323 passes through the through holes on the top and bottom surfaces of the perforating module 33, and the perforating module 33 is welded and fixed to the inclined wellbore 323.

[0065] The inner diameter of the perforating module 33 is larger than the outer diameter of the inclined wellbore 323;

[0066] A plurality of perforation holes 331 are evenly distributed on the circumferential wall of the perforation module 33 . The number, size and arrangement of the perforation holes can be pre-designed and processed to simulate different perforation parameters.

[0067] Example 2

[0068] A method for simulating 3D fracturing and perforating blastholes in a highly deviated well with multiple layers includes the following steps:

[0069] (I) Manufacturing simulated wellbore and perforation modules

[0070] Determine the inclination angle of the highly deviated well to be simulated, as well as the location and number of perforation holes according to the experimental plan, and manufacture and install the simulated wellbore and perforation module with the corresponding angle;

[0071] (II) Install the adapter into the simulated wellbore

[0072] Connect simulated perforating lines of different lengths (representing different fracturing fluid injection paths) to the middle line connector of the adapter in sequence. Then, install the simulated perforating lines one by one in order of length (from long to short) along the guide groove inside the simulated wellbore, ensuring that each perforating module is fully connected to the simulated perforating line to form a complete fluid channel.

[0073] (III) Assembling the simulated wellbore and the rock sample to form a simulated sample

[0074] When concrete rock samples are used as rock specimens, the simulated specimens are prepared as follows: Masking tape is cut to an appropriate width (i.e., the width between the upper and lower isolation rubber rings in a perforation module is just enough to cover the perforations) and evenly applied along the perforations. A simulated wellbore with the adapter, perforation module, and simulated perforation pipeline installed is placed in the center of a cement mold. Cement slurry is then evenly injected into the mold until the specimen reaches a size of 300 mm × 300 mm × 300 mm.

[0075] When using outcrop rock samples or downhole cores as rock samples, pre-treat the rock samples before placing the simulated wellbore into the pre-treated rock samples. The wellbore simulates the wellbore structure used in oil and gas production. It is necessary to ensure that the wellbore has a regular geometry, the diameter fully matches the subsequent simulated wellbore installation, and the wellbore wall is smooth and uniform to avoid the impact of processing errors on the experiment. The final wellbore drilling depth should be consistent with the cutting area of ​​the simulated formation to lay the foundation for subsequent fracture propagation experiments.

[0076] The pretreatment of the rock sample is specifically as follows:

[0077] (1) Cut and process the surface according to the size requirements (300×300mm) to obtain rock samples;

[0078] (2) drilling a wellbore on the rock sample processed in step (1); the diameter of the wellbore is 2 cm, and the depth of the wellbore is determined by the number of perforating modules;

[0079] (3) Cutting the rock sample at the appropriate location:

[0080] The specific requirements for the slot position are as follows: the perforation holes in the middle of the perforation module should be aligned with the slot, and the slot should be located between the upper and lower isolation rubber rings of the corresponding perforation module to ensure that the liquid discharged from the perforation holes in the middle of the perforation module can completely enter the slot, achieving the purpose of simulating the perforation holes in the real formation;

[0081] (IV) Simulation sample molding

[0082] When concrete rock samples are used as rock samples, the samples are left to stand and wait for the cement to completely solidify and wrap around the wellbore and perforation module;

[0083] When the rock sample is an outcrop rock sample or downhole core and its size meets the requirement of 300×300mm, the annulus between the rock sample and the simulated wellbore is cemented with glue. During the cementing process, the stability of the simulated wellbore at its inclination angle must be ensured so that it fits perfectly with the wellbore and all annular gaps are filled. After the cement is cured, a high-strength support structure is formed to ensure that the wellbore does not move at high inclinations. The reliability of the cementing operation directly affects the subsequent fracturing fluid flow path and the stability of the experimental results.

[0084] The specific method of glue injection is as follows: glue is injected into the wellbore immediately after each perforating module 33 is lowered, and the glue liquid will always be between two adjacent perforating modules 33. Alternatively, several packers can be lowered at once, and then glue is injected, so that the glue liquid is located above the top packer and below the end face of the rock drill hole. Tests have shown that the strength of both methods meets the requirements.

[0085] When rock samples are outcrop samples or downhole cores with dimensions less than 300×300mm, they must be encased in concrete to achieve the target size and ensure accurate loading of triaxial in-situ stresses. After cementing operations are completed, the concrete encasing process simulates the confining pressure environment of the formation. During concrete pouring, it is necessary to ensure that the three-dimensional encapsulation of the core is completely uniform, forming an external constraint layer with high rigidity and compressive resistance. Under the simulation conditions of highly deviated wells, the concrete encasing process must pay special attention to its adaptability to the inclination angle of the inclined pipe to ensure that the mechanical response of the formation pressure in the inclination direction is consistent with the actual working conditions. This step can truly simulate the confining pressure effect in the formation of highly deviated wells and is of great significance to the experimental results of fracture network expansion.

[0086] (V) moving the simulated specimen into the specimen chamber of the true triaxial hydraulic fracturing physical simulation experimental system; adjusting the position of the simulated specimen to ensure that the simulated wellbore and perforation module are aligned with the center of the pressure loading system; installing the three-way pressure plate, sealing gasket and other auxiliary components to achieve a tight mechanical connection and seal between the simulated specimen and the experimental system;

[0087] (VI) connecting the injection line to the fracturing fluid injection pump;

[0088] (VII) Start the three-dimensional confining pressure loading system and apply three-dimensional confining pressure to the test sample; the confining pressure loading must be kept stable and loaded step by step according to the confining pressure value of the experimental design to avoid the sample being damaged by sudden stress; during the confining pressure loading process, the computer monitoring system is used to ensure that the three-dimensional confining pressure remains balanced;

[0089] (VIII) starting the injection pump group and injecting the pre-mixed fracturing fluid into the sample according to the injection pressure and flow rate parameters set in the experimental plan; monitoring the injection pressure-time curve, the flow rate and pressure distribution of each cluster of fractures in real time by computer;

[0090] (IX) The experiment ends when the injection pressure-time curve shows a significant decrease (indicating that the crack propagation has stopped). After the experiment, the injection pump group is gradually turned off, and the confining pressure loading pump group is operated to perform a gradual pressure relief operation of the three-way confining pressure. After the pressure relief is completed, the cluster injection pipeline is disconnected from the injection pump group, and the sample is removed from the experimental chamber.

[0091] (Ⅹ) The removed specimens are mechanically cut or dissected to observe the morphology of the fracture network inside the specimens, including the length, width, direction of the fractures and the interaction between the fractures; combined with the experimental data, the coupling relationship between the fracture network morphology and the fluid flow characteristics is analyzed; by comparing the experimental results of different perforation schemes, inclination settings and injection strategies, a scientific basis is provided for optimizing the multi-cluster fracturing design of highly deviated wells.

[0092] The present invention adopts a multi-layer stereo fracturing simulation experiment, and the sample preparation can reflect the multi-layer system, that is, concrete samples with different formulations are used to simulate the stereo fracturing development conditions of reservoirs with different physical properties; multiple wellbores can be pre-buried in the sample and connected to the injection pump through multiple pipelines; when making the wellbores, the layer where the wellbores are placed can be controlled by changing the wellbores' length to simulate the vertical multi-layer stereo development conditions; at the same time, by changing the relative positions between the wellbores, the stereo fracturing development effects of the reservoir under different well networks and well spacing conditions can be simulated; by controlling the electrically controlled valves on the pipelines connecting the wellbores and the injection pumps, the overall transformation effects of different well networks on the reservoirs under different flow rates can be studied, providing a reliable experimental basis for the preparation of stereo development plans in actual engineering.

[0093] The applicant declares that the above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the scope of protection and disclosure of the present invention.

Claims

1. A multi-layer three-dimensional fracturing and perforating blasthole simulation device for highly deviated wells, characterized by: The invention comprises a fracturing fluid injection mechanism (1), a true triaxial hydraulic fracturing physical simulation experimental mechanism (2) and a simulation sample (3); the simulation sample (3) is placed in a sample cavity of the true triaxial hydraulic fracturing physical simulation experimental mechanism (2), and the fracturing fluid injection mechanism (1) is connected to the simulation sample (3).

2. The multi-layer three-dimensional fracturing and perforating blasthole simulation device for highly deviated wells according to claim 1 is characterized by: The fracturing fluid injection mechanism (1) comprises an injection pump group (11), a multi-channel flow control mechanism (12) and an adapter (13) connected in sequence; the injection pump group (11) comprises two injection pumps (111) both connected to a three-way valve (112), the other path of the three-way valve (112) being connected to the multi-channel flow control mechanism (12) via a main line; the multi-channel flow control mechanism (12) comprises multiple groups of flow control units, each of which comprises a branch line and a solenoid valve (121), a flow meter (122) and a pressure gauge (123) arranged in sequence on the branch line.

3. The multi-layer three-dimensional fracturing and perforating blasthole simulation device for highly deviated wells according to claim 2 is characterized by: The adapter (13) comprises a coaxially connected screw lock head (131) and a transition cavity (132), wherein multiple liquid flows are formed in the screw lock head (131) and the transition cavity (132), and multiple pipeline joints (133) are provided on the end face of the transition cavity (132) away from one end of the screw lock head; the liquid flow channel in the screw lock head (131) is connected to the liquid flow channel in the transition cavity (132) and the pipeline joints (133) in a one-to-one correspondence; and the other end of the branch line is connected to the liquid flow channel in the screw lock head (131).

4. The multi-layer three-dimensional fracturing and perforating blasthole simulation device for highly deviated wells according to claim 1 is characterized in that: The simulated sample (3) comprises a rock sample (31) and a simulated wellbore (32), wherein the simulated wellbore (32) is embedded in the rock sample (31), a wellbore packer is provided at the bottom end of the simulated wellbore (32), and a plurality of perforation modules (33) are provided on the simulated wellbore (32).

5. The multi-layer three-dimensional fracturing and perforating blasthole simulation device for highly deviated wells according to claim 4 is characterized in that: The rock sample (31) has a specification of 300mm×300mm×300mm, and the rock sample (31) is an outcrop rock sample or a concrete rock sample.

6. The multi-layer three-dimensional fracturing and perforating blasthole simulation device for highly deviated wells according to claim 4 is characterized by: The simulated wellbore (32) consists of a vertical wellbore (321), a horizontal wellbore (322) and an inclined wellbore (323) connected in sequence; the angle between the horizontal wellbore (322) and the inclined wellbore (323) is adjusted according to simulation requirements.

7. The multi-layer three-dimensional fracturing and perforating blasthole simulation device for highly deviated wells according to claim 4 is characterized by: The perforating module (33) is arranged on the inclined wellbore (323); the outer walls of both ends of the perforating module (33) are sleeved with sealing rubber rings (34); the perforating module (33) is connected to the pipeline joint (133) through the simulated perforating pipeline (35); a plurality of guide grooves are arranged in the simulated wellbore (32), and the simulated perforating pipeline (35) is embedded in the guide grooves; the perforating module (33) is a hollow cylindrical structure, and through holes are formed on the top and bottom surfaces of the perforating module (33); the inclined wellbore (323) passes through the through holes on the top and bottom surfaces of the perforating module (33), and the perforating module (33) is welded and fixed to the inclined wellbore (323); the inner diameter of the perforating module (33) is larger than the outer diameter of the inclined wellbore (323); and a plurality of perforating holes (331) are evenly distributed on the circumferential wall of the perforating module (33).

8. A simulation method using the multi-layer three-dimensional fracturing and perforating blasthole simulation device for highly deviated wells according to any one of claims 1 to 7, characterized in that: The following steps are involved: (I) Manufacturing simulated wellbore and perforation modules; (II) Installing the adapter into the simulated wellbore; (III) assembling the simulated wellbore and the rock sample to form a simulated specimen; (IV) Simulation specimen molding; (V) moving the simulated sample into the sample chamber of the true triaxial hydraulic fracturing physical simulation experimental system; (VI) connecting the injection line to the fracturing fluid injection pump; (VII) Applying three-dimensional confining pressure to the simulated specimen; (VIII) injecting the fracturing fluid into the simulated sample; (IX) After the experiment is completed, gradually turn off the injection pump group; after the pressure relief is completed, remove the simulated sample; (Ⅹ) The removed specimen is mechanically cut or dissected to observe the morphology of the crack network inside the specimen.

9. The method for simulating 3D fracturing and perforating blastholes in highly deviated wells according to claim 8, characterized in that: The step (III) is specifically as follows: When concrete rock samples are used as rock specimens, the simulated specimens are prepared as follows: a simulated wellbore with the adapter, perforating module, and simulated perforating pipeline installed is placed in the center of a cement mold. Subsequently, cement slurry is evenly injected into the mold until the specimen reaches a size of 300 mm × 300 mm × 300 mm. When the rock sample is an outcrop rock sample or a downhole core, a wellbore is first drilled on the rock sample, and then the simulated wellbore is placed in the wellbore.

10. The method for simulating 3D fracturing and perforating blastholes in highly deviated wells according to claim 8, characterized in that: The step (IV) of simulating sample forming is specifically as follows: When concrete rock samples are used as rock samples, the samples are left to stand and wait for the cement to completely solidify and wrap around the wellbore and perforation module; When the rock sample is an outcrop rock sample or a downhole core and the size meets the requirement of 300×300mm, the annulus between the rock sample and the simulated wellbore is cemented; When the rock sample is an outcrop rock sample or downhole core and the size is less than 300×300mm, it is wrapped with concrete to achieve the target size.

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