Large-size hydraulic fracturing physical model sample preparation and horizontal well perforation completion simulation method

Abstract

The invention relates to the technical field of shale gas reservoir volume fracturing yield increase, and discloses a large-size hydraulic fracturing physical model sample preparation and horizontal well perforation completion simulation method.According to the large-size physical model sample preparation and horizontal well perforation completion simulation method, a natural outcrop is used for preparing a large-size physical model sample bearing higher pressure, and well bottom and well wall cracking caused by high pressure in the fracturing process is avoided; shaft damage and other adverse effects; according to different experiment requirements, on the premise that the integrity of the sample is guaranteed, different perforation well completion schemes are efficiently implemented, the crack initiation position of the crack is controlled, the hydraulic crack layer penetrating effect is improved, the indoor true triaxial fracturing test is closer to the actual construction fracturing working condition, and obtained hydraulic crack initiation and expansion rule experiment data are more accurate.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas reservoir development, in particular to a shale gas reservoir volume fracturing production enhancement technology, and more specifically to a large-scale hydraulic fracturing model sample preparation and horizontal well perforation completion simulation method. Background Art

[0002] my country has rich reserves of shale oil and gas resources and great development potential, but the rock layers of the resources are deep and the geological conditions are complex, making them difficult to exploit. Hydraulic fracturing (abbreviated as fracturing) technology is one of the key technologies for efficient and low-cost development of shale gas. At present, a perforation fracturing process of "small sections and multiple clusters" for horizontal wells has been formed on site. Whether multiple clusters of fractures can be evenly initiated and expanded has become one of the important factors in improving oil and gas recovery rates, and also determines the success or failure of fracturing operations.

[0003] Conducting indoor large-scale true triaxial fracturing physical simulation tests can study the factors affecting the initiation and expansion of hydraulic fractures and effectively understand the initiation and expansion mechanism of hydraulic fractures. At present, the samples used for hydraulic fracturing physical simulation tests are mainly artificial rock samples, whose rock mechanical properties and natural weak surface properties are quite different from the actual formation conditions, making it difficult to reflect the actual formation conditions. In addition, there are problems such as long preparation cycles. In addition, the completion method of large physical model samples is mainly open hole wells, and perforation completion methods are less common. PVC pipe slitting is often used to simulate perforation, which is quite different from the actual working conditions. There are problems such as weak wellbore pressure bearing capacity, poor hydraulic fracture penetration effect caused by the lack of stress concentration points, and easy leakage of fracturing fluid from the bottom of the well and the well wall. Furthermore, most of the existing perforation completion methods are to perforate from the outer surface of the sample toward the wellbore, and then fill the excess holes, which destroys the integrity of the sample and causes deviations in the fracturing test results. A small number of perforation methods use high-pressure water jetting from the inside of the wellbore to the outside. However, it is difficult to penetrate thicker metal wellbores with only water jetting, and the perforation efficiency is low. Summary of the invention

[0004] In order to solve the problems and shortcomings existing in the above-mentioned prior art, the present invention proposes a method for preparing a large-size hydraulic fracturing physical model sample and simulating horizontal well perforation completion. The present invention uses natural outcrops to prepare large-size physical model samples that can withstand higher pressures, so as to avoid adverse effects such as cracking of the well bottom and well wall, and wellbore damage caused by high pressure during fracturing. Moreover, according to different experimental requirements, on the premise of ensuring the integrity of the sample, different perforation and completion schemes are efficiently implemented to control the initiation position of the cracks, improve the penetration effect of the hydraulic fractures, make the indoor true triaxial fracturing test closer to the actual construction fracturing conditions, and make the obtained experimental data on the initiation and expansion laws of the hydraulic fractures more accurate.

[0005] In order to achieve the above-mentioned object of the invention, the technical solution of the present invention is as follows: A method for preparing a large-size hydraulic fracturing model sample and simulating horizontal well perforation completion mainly includes the following steps: Step S1. Select a natural outcrop in the field as a raw material for preparing a mold sample, use a large-scale cutting device to directly cut the selected natural outcrop into a cubic outcrop rock sample matching the size of the fracturing equipment, and then use an angle grinder to level the surface of the cubic outcrop.

[0006] Furthermore, in the present invention, the selected natural outcrop is usually one of shale, sandstone, granite and conglomerate, and the rock mechanical properties, mineral composition and degree of development of natural weak planes of the selected natural outcrop should be similar to the core properties of the block under study.

[0007] Furthermore, in the present invention, the size of the cube outcrop rock sample that matches the size of the fracturing equipment is generally 30 cm×30 cm×30 cm, and the fracturing equipment is a large-size true triaxial fracturing equipment independently developed by China University of Petroleum (Beijing). In addition, in order to ensure uniform loading of the triaxial confining pressure on the sample surface during the true triaxial fracturing test, the surface of the cube outcrop should be leveled.

[0008] Step S2. Use a water drill to vertically drill a blind hole with a preset diameter and depth in the center of the face of the cube outcrop, then chisel out the drilled rock column and remove the remaining rock blocks to ensure that the bottom of the hole is flat.

[0009] In this embodiment, it should be noted that the face center is the center of any surface of the cube outcrop parallel to the pressure direction of the overburden formation, and any surface parallel to the pressure direction of the overburden formation is the surface of the shale outcrop cube with clearly visible bedding. Further, the bottom of the hole is ensured to be flat so that the wellbore can be vertically placed in the center of the hole and does not exceed the height of the borehole surface.

[0010] In the present invention, the diameter and depth of the holes drilled in the cubic outcrop are 25 mm-35 mm and 20 cm-30 cm, respectively. When drilling holes, the drilled rock column can be used to analyze the distribution characteristics of natural fractures, bedding, texture, etc. in the vicinity of the wellbore to determine or optimize the subsequent perforation scheme; further, the distribution characteristics of the natural fractures, bedding, texture, etc. include the position, number, width, density, etc. in the height direction.

[0011] Step S3. Select a stainless steel pipe with preset inner and outer diameters according to the size of the rock sample and the size of the injection pipe used for fracturing to make a simulated wellbore. When making the wellbore, first cut the steel pipe so that its length matches the hole depth, and then use a threading machine to thread the outer wall of the steel pipe with preset thread spacing and thread depth.

[0012] In the present invention, the preset inner diameter and outer diameter of the steel pipe are 20 mm-30 mm and 25 mm-35 mm respectively. The inner diameter of the steel pipe is specifically determined according to the diameter of the injection pipe used for fracturing. The outer diameter of the steel pipe should be smaller than the hole diameter of the cubic outcrop to reserve a solid glue annulus. The length of the steel pipe is consistent with the hole depth.

[0013] In the present invention, the threading machine is an improved Tiger King SQ50B1 threading machine, which taps from both ends to make the outer surface of the steel pipe covered with threads; the preset thread spacing and thread depth of the outer wall of the steel pipe are 1 mm-3 mm and 0.5 mm-2 mm respectively. The smaller the thread spacing and the greater the thread depth, the firmer the consolidation, but the greater the risk of deformation of the steel pipe, which will affect the sealing of the injection tube after insertion.

[0014] Step S4. Use tape to seal one end of the threaded steel pipe, and then use a rubber-tipped dropper to slowly drip AB epoxy resin glue from the open end of the other end of the steel pipe to achieve bottom hole consolidation, and finally form a simulated wellbore.

[0015] In the present invention, before using tape to seal the steel pipe, the cooling oil adhered to the steel pipe after threading should be cleaned and the burrs should be cleaned; the tape sealing method is to first wrap it around the outer wall of the end to be consolidated of the threaded steel pipe for more than two turns, then use two tapes to close the end in a "cross" shape, and finally wrap it around the outer wall of the closed end for more than two turns again.

[0016] In the present invention, when consolidating at the bottom of the well, the amount of AB epoxy resin glue dripped in is 3 ml-10 ml, so that the height of the solid glue is 1 cm-3 cm. The larger the height of the solid glue, the higher the bottom hole strength, but the smaller the perforation length range.

[0017] Step S5. Remove the sealing tape on the wellbore, place the entire wellbore vertically into the center of the hole with the consolidation end of the wellbore facing downward, and then use a rubber-tipped dropper to slowly drip AB epoxy resin glue from the annulus between the outer wall of the wellbore and the inner wall of the hole to achieve well wall consolidation.

[0018] In the present invention, the operation method for ensuring that the wellbore can be placed vertically in the center of the hole is, optionally, firstly evenly wrapping a waterproof tape of a certain thickness around the outer wall of the wellbore, then placing the wellbore into the hole and dripping glue from the annulus; optionally, after the glue dripping is completed, an external stabilizing frame is used to ensure that the wellbore does not deviate or fall over.

[0019] Furthermore, the amount of AB epoxy resin glue dripped in needs to fill the annulus. Since the volume of AB epoxy resin glue decreases when solidifying, and AB epoxy resin glue needs to fill the annulus, it needs to be supplemented by dripping multiple times after solidification.

[0020] Furthermore, in step S4 and step S5, the curing time of the AB epoxy resin glue is more than 24 hours, and curing is an exothermic process, so the curing time can be reduced by cooling.

[0021] Furthermore, in step S4 and step S5, the AB epoxy resin glue is slowly dripped in to ensure that the resin glue does not enter the inner wall of the steel pipe.

[0022] Step S6. Insert the hydraulic sandblasting perforating equipment gun into the simulated wellbore, and align the nozzle of the perforating gun head with the pre-perforating position by inserting, lifting and rotating the perforating gun to complete the preset perforating plan.

[0023] Furthermore, the hydraulic sandblasting perforating equipment is composed of a water inlet, a water storage tank, a booster pump, and a sand carrying (sand mixing) tank. The sand mixing tank is equipped with a sand carrying valve, and the sand output can be controlled by adjusting the valve.

[0024] Furthermore, the gun head of the hydraulic sandblasting perforating equipment is a consumable component and is designed to be detachable for easy replacement. At the same time, it is made of cemented carbide to improve durability under high-pressure sand-carrying flow abrasive conditions.

[0025] Furthermore, the nozzle (liquid outlet) of the hydraulic sandblasting perforating equipment gun head is designed to be 1 mm, which can meet the requirements of sand with suitable particle size to pass through, and at the same time can generate enough pressure to quickly penetrate the steel pipe. After repeated experiments, it was found that the suitable particle size of sand is 80 mesh garnet, and the sufficient pressure is above 25 MPa.

[0026] Furthermore, without considering the influence of perforation depth, the total perforation time, sand production time and sand output per unit should be controlled to ensure the consistency of hole diameter and perforation depth and eliminate irrelevant influencing factors.

[0027] Furthermore, the residual perforating sand inside the wellbore should be flushed out in time after perforating to avoid the residual sand from compacting and ensure the sealing effect after the injection pipe is inserted.

[0028] Furthermore, before the injection tube is inserted, sandpaper should be used to polish the wellbore entrance and inner wall to ensure the sealing effect after the injection tube is inserted.

[0029] Beneficial effects of the present invention: 1. The present invention selects and cuts field outcrops with rock mechanical properties and natural weak plane properties similar to those of the core of the studied block as rock samples for fracturing tests, which can more realistically simulate actual formation conditions and shorten the sample preparation cycle.

[0030] 2. After the simulated wellbore of the present invention is threaded, the well bottom and well wall are respectively consolidated, which can effectively improve the overall strength of cementing and avoid adverse effects such as cracking of the well bottom and well wall and wellbore damage caused by high pressure during fracturing.

[0031] 3. The present invention perforates from the inside of the simulated wellbore toward the surface of the sample during the simulated perforation completion, which can ensure the integrity of the sample; and the use of high-pressure water-carrying sand injection can efficiently penetrate the metal wellbore, which can meet the simulation of the "multi-cluster perforation" scheme with a large number of perforations.

[0032] 4. The present invention implements different perforation completion schemes by inserting, lifting and rotating inside a simulated wellbore, controls the initiation position of the cracks, improves the penetration effect of hydraulic fractures, makes the indoor true triaxial fracturing test closer to the actual construction fracturing conditions, and makes the experimental data on the initiation and expansion laws of hydraulic fractures more accurate.

[0033] 5. The present invention uses a detachable special hydraulic sandblasting perforating gun head, which is easy to replace and can meet the durability under the long-term abrasive working conditions of high-pressure sand-carrying flow. In addition, the nozzle of appropriate caliber can build up enough pressure to quickly penetrate the metal wellbore. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The foregoing and following detailed description of the present invention will become more apparent when read in conjunction with the following drawings, in which: Figure 1 The preparation of large-scale hydraulic fracturing model samples and the flow chart of horizontal well hydraulic sandblasting perforation completion provided by the embodiments of the invention; Figure 2 A schematic diagram of the structure of a physical model sample provided by an embodiment of the present invention; Figure 3 A diagram of hydraulic sandblasting perforation provided for an embodiment of the present invention; Figure 4 A schematic diagram of the hydraulic fracture morphology of a shale model sample after fracturing provided in an embodiment of the present invention.

[0035] In the figure: 1. Cube outcrop; 2. Bedding plane; 3. Annulus; 4. Threaded steel pipe; 5. Perforation; 6. Eyelet; 7. Stainless steel pipe; 8. Perforating gun; 9. Perforating gun head; 10. Nozzle; 11. Cross-cutting seam; 12. Bedding seam; 13. Longitudinal seam. DETAILED DESCRIPTION

[0036] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions for achieving the purpose of the present invention will be further described below through several specific embodiments. It should be noted that the technical solutions claimed for protection in the present invention include but are not limited to the following embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those skilled in the art without creative work shall fall within the scope of protection of the present invention.

[0037] Hydraulic fracturing (abbreviated as fracturing) technology is one of the key technologies for the efficient and low-cost development of shale gas. Conducting indoor large-scale true triaxial fracturing physical simulation tests can study the factors affecting the initiation and expansion of hydraulic fractures and effectively understand the initiation and expansion mechanism of hydraulic fractures. At present, the samples used for hydraulic fracturing physical simulation tests are mainly artificial rock samples. Their rock mechanical properties and natural weak surface properties are quite different from the actual formation conditions, making it difficult to reflect the actual formation conditions. In addition, there are problems such as long preparation cycles. In addition, the completion method of large physical model samples is mainly open hole wells, and perforation completion methods are less common. PVC pipe slitting is often used to simulate perforation, which is quite different from the actual working conditions. There are problems such as weak wellbore pressure bearing capacity, poor hydraulic fracture penetration effect caused by the lack of stress concentration points, and easy leakage of fracturing fluid from the bottom of the well and the well wall. Furthermore, most of the existing perforation completion methods are to perforate from the outer surface of the sample toward the wellbore, and then fill the excess holes, which destroys the integrity of the sample and causes deviations in the fracturing test results. A small number of perforation methods use high-pressure water jetting from the inside of the wellbore to the outside. However, it is difficult to penetrate thicker metal wellbores with only water jetting, and the perforation efficiency is low.

[0038] Based on this, the embodiment of the present invention proposes a method for preparing a large-scale hydraulic fracturing physical model sample and simulating horizontal well perforation completion. The present invention first uses natural outcrops to prepare cubic rock samples that match the size of the fracturing equipment, and then determines the parameters of the simulated wellbore according to the size of the rock sample and the size of the injection pipe used for fracturing, processes the simulated wellbore according to the parameters, and finally puts the simulated wellbore into the cubic outcrop rock sample and consolidates the bottom of the well and the well wall, and finally inserts the hydraulic sandblasting perforating equipment gun into the wellbore, and by inserting, lifting, and rotating the perforating gun, the nozzle of the perforating gun head is aligned with the pre-perforating position, and finally the preset perforating scheme is completed. The physical model sample prepared by the method of the present invention can make the test results closer to the actual construction fracturing conditions during the subsequent indoor true triaxial fracturing test, so that the obtained experimental data of the hydraulic fracture initiation and expansion law are more accurate.

[0039] This embodiment discloses a method for preparing a large-scale hydraulic fracturing physical model sample and simulating horizontal well perforation and completion. This embodiment uses the natural outcrop of the Longmaxi Formation collected in the Changning area of ​​the Sichuan Basin in China. By cleaning the weathered rock layer near the outcrop, mechanical means are used to excavate large rocks along the thickness direction of the shale. The shale outcrop has an average siliceous mineral content of 51.7%, an average carbonate mineral content of 9.5%, an average clay mineral content of 33.2%, and an average pyrite content of 5.6%, which is similar to the properties of the downhole core in the Changning-Weiyuan block of the Longmaxi Formation under study, and can simulate the actual formation conditions more realistically. The specific physical model sample preparation and perforation completion simulation process are as follows.

[0040] Step S1. Use a large-scale cutting device to cut a natural outcrop selected in the field into a cubic outcrop 1 matching the size of the fracturing equipment as a rock sample, and use an angle grinder to level the surface of the cubic outcrop 1.

[0041] In this embodiment, large-scale cutting equipment is used to directly cut the outcrop in the field. The size of the cubic outcrop after cutting is 30 cm×30 cm×30 cm. The outcrop size can adapt to the large-scale true triaxial fracturing equipment independently developed by China University of Petroleum (Beijing).

[0042] Step S2. Use a water drill to vertically drill a hole 6 of a preset diameter and depth in the center of the face of the cubic outcrop 1, chisel out the rock column drilled under and remove the remaining rock blocks to ensure that the bottom of the hole is flat.

[0043] In this embodiment, the structure of the prepared large-scale shale outcrop cubic fracturing mold sample can be referred to in the attached manual. Figure 2 As shown, it contains a bedding plane 2, and the horizontal well trajectory is parallel to the bedding plane. Therefore, in order to simulate a horizontal well, a hole 6 with a preset diameter and depth should be drilled vertically from the center of the face of the cubic outcrop 1. The diameter and depth of the hole 6 are 30 mm and 26 cm, respectively.

[0044] Furthermore, in this embodiment, the drilled rock column can be used to analyze the distribution characteristics of natural fractures near the wellbore to determine or optimize subsequent perforation schemes. For example, the perforation 5 should avoid directly connecting with natural fractures near the wellbore.

[0045] Step S3. Select a stainless steel pipe 7 with a preset inner diameter and outer diameter according to the size of the rock sample and the size of the injection pipe used for fracturing to make a simulated wellbore. When making the simulated wellbore, first cut the stainless steel pipe 7 so that its length matches the hole depth, and then use a threading machine to thread the outer wall of the steel pipe with a preset thread spacing and thread depth to finally form a threaded steel pipe 4.

[0046] In this embodiment, the inner diameter and outer diameter of the stainless steel pipe 7 used to make the simulated wellbore are 22 mm and 25 mm respectively, and the inner diameter of the stainless steel pipe 7 is adapted to the outer diameter of the injection pipe of 21.5 mm, and a 5 mm annulus 3 is reserved for dripping glue to achieve well wall consolidation. Before threading the steel pipe, adjust the clamp and the tooth plate to the same height, adjust the tapping spacing and tapping depth to 1.5 mm and 1 mm respectively, tap from both ends, so that the outer surface of the stainless steel pipe 7 is covered with threads, and the thread spacing and thread depth of the outer wall thread of the steel pipe obtained by processing are 1 mm-3 mm and 0.5 mm-2 mm respectively.

[0047] Step S4. Use tape to seal one end of the threaded steel pipe 4, and then use a rubber-tipped dropper to slowly drip AB epoxy resin glue from the open end of the other end of the steel pipe to the sealed end of the steel pipe to achieve bottom hole consolidation.

[0048] In this embodiment, before using the adhesive tape for sealing, clean the cooling oil stuck on the steel pipe after threading and use a file to clean the burrs; first wrap it twice along the outer wall of the end to be consolidated of the threaded steel pipe 4, then use two tapes to close the end in a cross shape, and finally wrap it twice again along the outer wall of the closed end. The dripping amount of the AB epoxy resin glue is 5 ml, and the height of the solid glue is 1.5 cm. The threaded steel pipe 4 after dripping glue is placed vertically in a container filled with cold water to accelerate solidification and shorten the bottom hole consolidation period.

[0049] Step S5. Remove the sealing tape, place the threaded steel pipe 4 vertically into the center of the hole 6 with the consolidation end of the threaded steel pipe 4 facing downward, and then use a rubber-tipped dropper to slowly drip AB epoxy resin glue into the annulus 3 formed between the outer wall of the threaded steel pipe 4 and the inner wall of the hole. The AB epoxy resin glue is consolidated in the annulus 3, and finally the well wall is consolidated.

[0050] In this embodiment, after removing the sealing tape of the threaded steel pipe 4, it is also necessary to inject water from the unconsolidated end of the threaded steel pipe 4 to observe whether the consolidated end leaks water, so as to preliminarily judge the consolidation quality. Furthermore, when consolidating the well wall, the amount of AB epoxy resin glue slowly dripped along the annulus 3 should finally fill the annulus. After dripping the glue, the flow process of the resin glue is accompanied by the extrusion of bubbles, and the liquid level of the annulus 3 will drop. Therefore, it is necessary to add glue dripping once every 1 hour, and a total of 2 times.

[0051] Step S6. Insert the hydraulic sandblasting perforating equipment gun 8 into the wellbore, and align the nozzle 10 of the perforating gun head 9 with the pre-perforating hole 5 position by inserting, lifting and rotating the perforating gun 8 to complete the preset perforating plan.

[0052] In this embodiment, 80 mesh garnet is used as the perforating sand. The perforating scheme is formed by the experimental requirements and the weak surface distribution of the drilled rock column. The perforating scheme is set to spiral perforation, with a total of 5 clusters of perforations, 3 perforations in each cluster, a phase of 120° between holes, 0.5 cm between holes, and 2.5 cm between clusters. The perforating depth is controlled, and the overall perforating time is determined to be 2 minutes based on the pre-perforating time, of which the sand-adding perforating time is 1.5 minutes. Figure 3As shown, the perforating gun 8 is inserted into the wellbore, and the nozzle 10 of the perforating gun head 9 is aligned with the position 5 to be perforated by rotating and lifting the perforating gun 8. The water inlet valve is opened, and the booster pump is turned on after the water inlet pressure is stable. When the water outlet pressure is stable between 25-30 MPa, the sand-carrying valve is opened, and the high-pressure water flows through the sand tank, carrying sand particles and ejected from the small-diameter nozzle 10, penetrating the threaded steel pipe 4 and the annulus 3 and injecting into the cubic outcrop 1 to a certain depth (1 cm). After the perforation is completed, the perforating gun head 9 is used to repeatedly clean the residual sand inside the wellbore without adding sand and turning on the booster pump, so as to prevent the residual sand from hardening and affecting the sealing of the injection pipe after insertion.

[0053] Before the fracturing experiment, sandpaper and files were used to clean the AB epoxy resin glue that accidentally dripped into the inner wall of the wellbore to ensure the smooth inner wall of the wellbore and avoid the unevenness inside the wellbore that affects the sealing after the injection pipe is inserted. The fracturing experiment used a large-scale true triaxial fracturing equipment independently developed by China University of Petroleum (Beijing). When simulating on-site fracturing operations, the overburden pressure (σ v ) is applied perpendicular to the bedding plane 2, the maximum horizontal principal stress (σ H ) is applied perpendicular to the wellbore, the minimum horizontal principal stress (σ h ) is applied in the direction parallel to the wellbore. The hydraulic fracture morphology of the prepared large-scale shale outcrop cubic fracturing model specimen after fracturing is shown in Figure 3 As shown, hydraulic fracturing produces two transverse fractures 11, two bedding fractures 12 and two longitudinal fractures 13. The initiation and expansion of the fractures are good, the hydraulic fractures have a good layer penetration effect, and the wellbore can still maintain structural integrity after being subjected to high pressure.

[0054] The above description is only a preferred embodiment of the present invention and does not constitute any form of hindrance to the present invention. Any simple modification or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for preparing a large-scale hydraulic fracturing model sample and simulating horizontal well perforation completion, characterized in that: The following steps are involved: Step S1. Processing the natural outcrop into a rock sample with a cubic structure, and drilling a hole in the center of the surface of the cubic rock sample; Step S2. Determine the simulated wellbore parameters according to the rock sample size and the size of the injection pipe used for fracturing, and process the simulated wellbore, wherein the outer wall of the simulated wellbore is provided with threads; Step S3. seal one end of the simulated wellbore, and drip a plugging glue from the other open end of the wellbore to the sealed end of the wellbore to achieve bottom hole consolidation; Step S4. Place the wellbore into the center of the hole with the consolidation end of the wellbore facing downward, and fill the annulus between the wellbore and the hole with cementing medium to achieve wellbore wall consolidation; Step S5. Insert the hydraulic sandblasting perforating equipment gun into the wellbore, and align the nozzle of the perforating gun head with the pre-perforating position by inserting, lifting and rotating the perforating gun to complete the preset perforating plan.

2. The method for preparing a large-scale hydraulic fracturing model sample and simulating horizontal well perforation completion according to claim 1 is characterized in that: The rock mechanical properties, mineral composition and degree of development of natural weak planes of the selected natural outcrops are similar to the core properties of the studied block.

3. The method for preparing a large-scale hydraulic fracturing model sample and simulating horizontal well perforation completion according to claim 1, characterized in that: The face center is the center of any surface of the cubic outcrop parallel to the pressure direction of the overlying rock formation.

4. The method for preparing a large-scale hydraulic fracturing model sample and simulating horizontal well perforation completion according to claim 3 is characterized in that: Any surface parallel to the pressure direction of the overlying strata is a surface of the outcrop cube with clearly visible stratification.

5. The method for preparing large-scale hydraulic fracturing model specimens and simulating horizontal well perforation completion according to claim 1, characterized in that: When drilling holes, the rock column drilled is used to analyze the distribution characteristics of natural fractures, bedding and texture near the wellbore to determine or optimize the perforation plan.

6. The method for preparing large-scale hydraulic fracturing model specimens and simulating horizontal well perforation completion according to claim 1, characterized in that: Use tape to seal one end of the simulated wellbore. When sealing, first wrap it around the outer wall of the wellbore to be consolidated for more than two turns, then use two strips of tape to close the end of the wellbore in a cross shape, and finally wrap it around the outer wall of the closed end for more than two turns again.

7. The method for preparing large-scale hydraulic fracturing model specimens and simulating horizontal well perforation completion according to claim 1, characterized in that: The gun head of the hydraulic sandblasting perforating equipment is made of hard alloy material.

8. The method for preparing large-scale hydraulic fracturing model specimens and simulating horizontal well perforation completion according to claim 1, characterized in that: The cementing medium fills the annulus after being consolidated.

9. The method for preparing a large-scale hydraulic fracturing model sample and simulating horizontal well perforation completion according to claim 1, characterized in that: The nozzle diameter of the hydraulic sandblasting perforating equipment gun head is 1 mm.

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