Perforated wellbore, combined wellbore, hole abrasion simulation device and simulation method

Abstract

The present application provides a perforated wellbore, which includes: a cylinder body, which is tubular, and wellbore connection flanges are provided at both ends of the cylinder body for connecting adjacent wellbores; a perforating pipe, which is arranged on the cylinder body, the first end of the perforating pipe communicates with the inside of the cylinder body through perforation holes, and a perforating connection flange is formed at the second end thereof, and the perforating connection flange is used to connect with a connection pipeline flange of a perforating pipe connection pipeline so as to communicate the perforating pipe with the perforating pipe connection pipeline; and an internal liner, the outer wall of which is detachably connected to the inner wall of the perforating pipe. The present application is beneficial to studying the abrasion effect of solid proppant particles in the sand-carrying fluid on the internal liner installed at the perforation holes of the wellbore during the hydraulic fracturing transformation process, and is also beneficial to studying the influence of the number of perforation clusters, cluster spacing, the number of holes, hole diameter, construction parameters, etc. on the hole abrasion effect, so as to provide theoretical support for fracturing scheme design and fracturing construction analysis.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic fracturing, and particularly to a perforated wellbore, a combined wellbore, a hole erosion simulation device and a simulation method. Background Art

[0002] "Multi-stage and multi-cluster" fracturing of horizontal wells is an important stimulation measure for unconventional oil and gas development. During the hydraulic fracturing process, a large amount of proppant-carrying fluid is injected into the formation through the wellbore and perforation holes by a fracturing truck fleet to form fracture support fractures. When the proppant-carrying fluid flows through the wellbore to the perforation holes, the flow direction of the proppant-carrying fluid changes by 90°. At the same time, the diameter of the perforation holes is much smaller than that of the wellbore, resulting in a significant increase in the fluid flow velocity after the proppant-carrying fluid enters the perforation holes. Due to the change in the flow direction and the increase in the flow velocity, the erosion effect of the proppant in the proppant-carrying fluid on the perforation holes is greatly increased. During the "multi-stage and multi-cluster" fracturing of horizontal wells, the erosion effect of the perforation holes has an important impact on the shape and inner diameter of the perforation holes. At the same time, the change in the inner diameter of the perforations also has an important impact on the friction resistance of the perforation holes, the fluid flow velocity, and the flow diversion between perforation clusters.

[0003] Existing experimental simulation devices have conducted a large number of studies on the erosion effect of hydraulic jetting on holes, and have studied the erosion effect of different variables of hydraulic jetting on perforation holes through laboratory experiments and numerical simulations. Different variables of hydraulic jetting include jet velocity, nozzle diameter, abrasive, jet pressure, etc.

[0004] However, in the field of research on perforation hole erosion during the fracturing transformation process, the existing technology mainly focuses on numerical simulation. There is no experimental simulation device and simulation method for the erosion phenomenon of wellbore perforation holes during the hydraulic fracturing process in the existing technology. Therefore, the existing technology cannot study the erosion effect of solid proppant particles in the proppant-carrying fluid on the wellbore perforation holes through experimental simulation during the hydraulic fracturing transformation process, nor can it specifically study the influence of the number of perforation clusters, cluster spacing, number of holes, hole diameter, construction parameters, etc. on the hole erosion effect through experimental simulation, resulting in a lack of theoretical support for fracturing scheme design and fracturing construction analysis. Summary of the Invention

[0005] In view of the above problems in the existing technology, the present application proposes a perforated wellbore, a combined wellbore, a hole erosion simulation device and a simulation method. The present application is conducive to studying the erosion effect of solid proppant particles in the proppant-carrying fluid on the wellbore perforation holes during the hydraulic fracturing transformation process by using the perforated wellbore, and is also conducive to studying the influence of the number of perforation clusters, cluster spacing, number of holes, hole diameter, construction parameters, etc. on the hole erosion effect, thereby being conducive to providing theoretical support for fracturing scheme design and fracturing construction analysis.

[0006] In a first aspect, the present invention provides a perforated wellbore, which includes: a cylinder body, which is tubular, and wellbore connection flanges are provided at both ends of the cylinder body, and the wellbore connection flanges are used to connect adjacent wellbores; a perforating pipe, which is arranged on the cylinder body, the first end of the perforating pipe communicates with the inside of the cylinder body through perforation holes, and a perforating connection flange is formed at the second end thereof, and the perforating connection flange is used to connect with a connection pipeline flange of a perforating pipe connection pipeline so as to communicate the perforating pipe with the perforating pipe connection pipeline; and an internal liner, the outer wall of which is detachably connected to the inner wall of the perforating pipe. The perforated wellbore of this embodiment includes a detachable internal liner. The internal liner is replaced before each simulation. By observing the changes of the internal liner before and after the simulation, it is beneficial to study the abrasion effect of solid proppant particles in the sand-carrying fluid on the perforation holes of the wellbore during the hydraulic fracturing transformation process, and it is also beneficial to study the influence of the number of perforation clusters, cluster spacing, hole number, hole diameter and construction parameters on the hole abrasion effect, so as to provide theoretical support for the design of the fracturing plan and the analysis of the fracturing construction.

[0007] In an embodiment of the first aspect, the outer wall of the internal liner is threadedly connected to the inner wall of the perforating pipe. Through this embodiment, it is beneficial to the rapid replacement of the internal liner.

[0008] In an embodiment of the first aspect, the hole body of the internal liner is a cylindrical hole for simulating perforation holes; one end of the hole of the internal liner close to the perforating connection flange is a regular hexagonal prism-shaped hole for engaging with a hexagonal wrench, so as to install the internal liner in the perforating pipe. Through this embodiment, the cylindrical hole is used to characterize the abrasion effect of solid proppant particles in the sand-carrying fluid on the internal liner installed at the perforation holes of the wellbore during the hydraulic fracturing transformation process; the regular hexagonal prism-shaped hole is used to engage with a hexagonal wrench, so that the internal liner can be installed in the perforating pipe labor-savingly by using the hexagonal wrench.

[0009] In a second aspect, the present invention further provides a combined wellbore, which includes the perforated wellbore of the first aspect and any of its embodiments. By using this combined wellbore, it is possible to study the abrasion effect of solid proppant particles in the sand-carrying fluid on the internal liner installed at the perforation holes of the wellbore during the hydraulic fracturing transformation process, and it is also beneficial to study the influence of the number of perforation clusters, cluster spacing, hole number, hole diameter and construction parameters on the hole abrasion effect, so as to provide theoretical support for the design of the fracturing plan and the analysis of the fracturing construction.

[0010] In an embodiment of the second aspect, the combined wellbore further includes a non-perforated wellbore, and the non-perforated wellbore includes a cylinder body, the cylinder body is tubular and wellbore connection flanges are provided at both ends thereof, and the wellbore connection flanges are used to connect adjacent wellbores. Through this embodiment, a non-perforated wellbore is provided for the simulation, which is beneficial to the smooth progress of the simulation.

[0011] In one embodiment of the second aspect, the combined wellbore is a single-stage multi-cluster perforated wellbore, which includes the perforated wellbore and the non-perforated wellbore arranged alternately, and both ends of the combined wellbore are the non-perforated wellbores. Through this embodiment, it is beneficial to study the influence of the number of perforation clusters, the perforation cluster spacing, the number of perforation holes, the size of perforation holes, etc. on the degree of hole erosion.

[0012] In one embodiment of the second aspect, the combined wellbore is a single-stage single-cluster perforated wellbore, with the non-perforated wellbores at both ends, and a plurality of perforated wellbores connected end to end are arranged between the two non-perforated wellbores. Through this embodiment, it is beneficial to study the influence of the number of perforation holes, the perforation phase angle, the size of perforation holes, etc. on the degree of hole erosion.

[0013] In the third aspect, the present invention also provides a hole erosion simulation device, which includes the combined wellbore of the second aspect and any of its embodiments. Using this simulation device, it is possible to study the erosion effect of solid proppant particles in the sand-carrying fluid on the internal liner installed at the perforation holes of the wellbore during the hydraulic fracturing transformation process, and it is also beneficial to study the influence of the number of perforation clusters, cluster spacing, hole quantity, hole diameter, and construction parameters, etc. on the hole erosion effect, thereby being beneficial to providing theoretical support for fracturing plan design and fracturing construction analysis.

[0014] In one embodiment of the third aspect, the simulation device further includes: a stirring and pumping system, which configures and stirs the fracturing fluid and proppant to form a sand-carrying fluid and pumps the uniformly configured fracturing fluid or sand-carrying fluid to the combined wellbore; a reflux collection system for liquid reflux and proppant collection, whose first end is communicated with the perforation pipe connection pipeline on the combined wellbore; its second end is communicated with the stirring device in the stirring and pumping system, and a control system for controlling the operation of the simulation device and recording simulation data. Through this embodiment, it can be applied to simulate the influence of a small amount of proppant and a large amount of proppant on the hole erosion effect, can be used to study the erosion effect of solid proppant particles in the sand-carrying fluid on the internal liner installed at the perforation holes of the wellbore during the hydraulic fracturing transformation process, and it is also beneficial to study the influence of the number of perforation clusters, cluster spacing, hole quantity, hole diameter, and construction parameters, etc. on the hole erosion effect, thereby being beneficial to providing theoretical support for fracturing plan design and fracturing construction analysis.

[0015] In an embodiment of the third aspect, the mixing and pumping system includes: a water source for supplying water required for simulation to the simulation device; a proppant automatic addition device for supplying proppant to the simulation device; a mixing device connected to the water source and the proppant automatic addition device for configuring fracturing fluid and mixing the fracturing fluid and proppant to form a sand-carrying fluid; a high-capacity liquid injection pump for pumping the fracturing fluid or the sand-carrying fluid and controlling the flow rate of the liquid entering the combined wellbore; a flow meter located between the high-capacity liquid injection pump and the inlet of the combined wellbore; and a pressure gauge also located between the high-capacity liquid injection pump and the inlet of the combined wellbore. Through this embodiment, the mixing and pumping system can mix the fracturing fluid or the sand-carrying fluid and transport the mixed fracturing fluid or sand-carrying fluid to the combined wellbore to ensure the smooth progress of the simulation.

[0016] In an embodiment of the third aspect, the reflux collection system includes: at least one collection device connected to the perforated wellbore for collecting proppant; and a pipeline connector located on the pipeline connecting the collection device and the mixing device in the mixing and pumping system. Through this embodiment, the reflux collection system can assist in realizing the reflux of the liquid and the collection of the proppant to ensure the smooth progress of the simulation.

[0017] In an embodiment of the third aspect, the collection device includes: a tee connected to the perforated pipe connection pipeline; an inlet pipeline connected to the perforated wellbore; and a cleaning liquid discharge port for discharging residual liquid or cleaning liquid. Through this embodiment, it can be ensured that when simulating the abrasion effect of a small amount of proppant on the internal liner installed at the perforation holes, the collection device can collect the proppant, and when simulating the abrasion effect of a large amount of proppant on the internal liner installed at the perforation holes, the proppant can bypass the collection device and directly enter the pipeline connector for circulating flow, thus ensuring the smooth progress of the simulation.

[0018] In an embodiment of the third aspect, a flow meter and a pressure gauge are provided on the pipeline connecting the perforated pipe connection pipeline and the collection device. Through this embodiment, the flow meter and the pressure gauge are respectively used to measure the flow rate and pressure of the mixed liquid flowing from the perforated wellbore into the tee, so as to facilitate the real-time regulation of the simulation device by the control system.

[0019] In an embodiment of the third aspect, the outlet end of the combined wellbore is connected to the pipeline connector. Through this embodiment, the safety of the combined wellbore during the simulation and the cleaning of the combined wellbore after the simulation can be ensured.

[0020] In an embodiment of the third aspect, the control system includes a power supply, a controller, and a recording computer that are communicatively connected to each other. Through this embodiment, it is beneficial to the automated operation of the simulation device.

[0021] In an embodiment of the third aspect, the controller is communicatively connected to the proppant automatic addition device, the stirring device, the large-displacement liquid injection pump, each flowmeter, and each pressure gauge. Through this embodiment, it is beneficial for the controller to control each device and collect analog data in real time.

[0022] Fourth aspect, the present invention also provides a simulation method using the perforation erosion simulation device of the third aspect and any of its embodiments. The simulation method includes the following steps: setting liquid parameters, proppant parameters, and combined wellbore parameters; the mixing and pumping system pumps the sand-carrying fluid into the combined wellbore through the inlet end of the combined wellbore, and the sand-carrying fluid is the mixed fracturing fluid and proppant; part of the sand-carrying fluid flows through the inner liner of the perforated wellbore to the pipeline connector and then circulates back to the mixing device; changing the liquid parameters, proppant parameters, and combined wellbore parameters and repeating the simulation. Using this simulation method, it is possible to provide a feasible simulation method for studying the erosion effect of proppants on the inner liner installed at the perforation holes.

[0023] In an embodiment of the fourth aspect, the step that part of the sand-carrying fluid flows through the inner liner of the perforated wellbore to the pipeline connector and then circulates back to the mixing device includes the following steps: the sand-carrying fluid leaving the inner liner enters the collection device, the collection device collects the proppant, and the fracturing fluid in the sand-carrying fluid circulates back to the mixing device through the pipeline connector to recycle the fracturing fluid. Through this embodiment, when simulating the erosion effect of a small amount of proppants on the perforation holes, the collection device can collect the proppants for subsequent weighing, thus preparing for quantitative analysis.

[0024] In an embodiment of the fourth aspect, the step that part of the sand-carrying fluid flows through the inner liner of the perforated wellbore to the pipeline connector and then circulates back to the mixing device includes the following steps: the sand-carrying fluid leaving the inner liner directly flows into the pipeline connector through the pipeline to recycle the sand-carrying fluid. Through this embodiment, when simulating the erosion effect of a large amount of proppants on the inner liner installed at the perforation holes, the proppants can bypass the collection device and directly enter the pipeline connector for circulating flow, thus ensuring the smooth progress of the simulation.

[0025] In an embodiment of the fourth aspect, each of the inner liners is numbered and its corresponding position and the experimental simulation serial number are recorded; the net weight of each of the inner liners is weighed before and after the simulation, and each of the inner liners is photographed after the simulation to study its shape change. Through this embodiment, it is beneficial to improve the accuracy of the simulation results.

[0026] The perforated wellbore, combined wellbore, perforation erosion simulation device, and simulation method provided by this application have the following beneficial effects compared with the prior art.

[0027] 1. The perforated wellbore includes a detachable inner liner, which is replaced before each simulation. By observing the changes in the shape and quality of the inner holes of the inner liner before and after the simulation, it is beneficial to study the abrasion effect of solid proppant particles in the sand-carrying fluid on the wellbore perforation holes during the hydraulic fracturing process. It is also beneficial to study the influence of the number of perforation clusters, cluster spacing, number of holes, hole diameter, and construction parameters on the hole abrasion effect, thereby providing theoretical support for the design of fracturing schemes and the analysis of fracturing construction.

[0028] 2. The combined wellbore includes a perforated wellbore and a non-perforated wellbore, so as to be able to simulate a single-stage multi-cluster perforated wellbore and a single-stage single-cluster perforated wellbore, providing a basic support for studying the influence of the number of perforation clusters, perforation cluster spacing, number of perforation holes, perforation hole size, etc. on the abrasion degree of the inner liner.

[0029] 3. The simulation device includes a combined wellbore, a stirring and pumping system, a reflux collection system, and a control system, thus simulating the influence of proppants on the abrasion effect of perforation holes. It can be used to study the abrasion effect of solid proppant particles in the sand-carrying fluid on the wellbore perforation holes during the hydraulic fracturing process. It is also beneficial to study the influence of the number of perforation clusters, cluster spacing, number of holes, hole diameter, and construction parameters on the hole abrasion effect, thereby providing theoretical support for the design of fracturing schemes and the analysis of fracturing construction.

[0030] 4. The simulation method can simulate the abrasion effect of a small amount of proppants on the perforation holes and can also simulate the abrasion effect of a large amount of proppants on the perforation holes.

[0031] 5. By labeling each of the inner liners and recording their corresponding positions and the experimental simulation serial numbers; weighing the net weight of each of the inner liners before and after the simulation, and taking pictures of each of the inner liners after the simulation to study their shape changes, it is beneficial to improve the accuracy of the simulation results.

[0032] The above technical features can be combined in various suitable ways or replaced by equivalent technical features as long as the purpose of the present invention can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Hereinafter, the present invention will be described in more detail based on embodiments with reference to the drawings, wherein:

[0034] Figure 1 Shows a schematic structural diagram of a perforated wellbore according to an embodiment of the present invention;

[0035] Figure 2 Shows a schematic structural diagram of a non-perforated wellbore according to an embodiment of the present invention;

[0036] Figure 3Shows the connection schematic diagram of the perforated wellbore and the connection pipeline of the perforating pipe according to an embodiment of the present invention;

[0037] Figure 4 Shows the structural schematic diagram of the internal liner according to an embodiment of the present invention;

[0038] Figure 5 Shows the structural schematic diagram of a single - stage multi - cluster perforated wellbore according to an embodiment of the present invention;

[0039] Figure 6 Shows the structural schematic diagram of a single - stage single - cluster perforated wellbore according to an embodiment of the present invention;

[0040] Figure 7 Shows the structural schematic diagram of a simulation device according to an embodiment of the present invention.

[0041] List of reference numerals:

[0042] 1 - Perforated wellbore; 2 - Perforation holes; 3 - Perforation connection flange; 4 - Screw holes; 5 - Wellbore connection flange; 7 - Non - perforated wellbore; 10 - Cylinder; 11 - Perforating pipe; 13 - Internal liner; 14 - Thread; 16 - Connection pipeline flange; 17 - Bolt; 18 - Perforating pipe connection pipeline; 21 - Cylindrical hole; 22 - Regular hexagonal prism - shaped hole; 26 - Front connection flange of the combined wellbore; 27 - Rear connection flange of the combined wellbore; 33 - Water source; 34 - Proppant automatic adding device; 35 - Stirring device; 36 - Drain outlet valve; 37 - Ball seat valve; 38 - High - displacement liquid injection pump; 39 - Flowmeter; 40 - Pressure gauge; 41 - Connection pipeline; 50 - Transmission line; 52 - Collection device; 53 - Inlet pipeline; 54 - Cleaning liquid discharge outlet; 58 - Control valve; 59 - Three - way; 62 - Pipeline connector; 65 - Control wire; 68 - Controller; 69 - Power supply; 70 - High - power line; 72 - Recording computer.

[0043] In the drawings, the same components are denoted by the same reference numerals. The drawings are not drawn to actual scale. Detailed embodiments

[0044] The present invention will be further described below in conjunction with the drawings.

[0045] As Figure 1 and Figure 3As shown in the figure, this embodiment provides a perforated wellbore 1, which includes: a cylinder body 10, which is tubular, and wellbore connection flanges 5 are provided at both ends of the cylinder body 10 for connecting adjacent wellbores; a perforating pipe 11, which is arranged on the cylinder body 10, and the first end of the perforating pipe 11 communicates with the inside of the cylinder body 10 through a perforation hole 2, and a perforating connection flange 3 is formed at its second end for connecting with a connection pipeline flange 16 of a perforating pipe connection pipeline 18 to communicate the perforating pipe 11 with the perforating pipe connection pipeline 18; and an internal liner 13, whose outer wall is detachably connected to the inner wall of the perforating pipe 11.

[0046] The perforated wellbore 1 includes a tubular cylinder body 10, and wellbore connection flanges 5 are provided at both ends of the cylinder body 10 for connecting adjacent wellbores. The wellbore includes a perforated wellbore 1 and a non-perforated wellbore 7. Adjacent wellbores are connected to each other through the wellbore connection flanges 5. Preferably, six screw holes 4 are evenly distributed on the flange plate of the wellbore connection flange 5 for partially accommodating bolts 17 to facilitate pipeline connection using bolts 17.

[0047] Perforation holes 2 are provided on the cylinder body 10, the first end of the perforating pipe 11 communicates with the inside of the cylinder body 10 through the perforation holes 2, and a perforating connection flange 3 is formed at the second end of the perforating pipe 11 for connecting the perforating pipe connection pipeline 18. A connection pipeline flange 16 is formed at one end of the perforating pipe connection pipeline 18, and the perforating connection flange 3 is connected to the connection pipeline flange 16 to communicate the perforating pipe 11 and the perforating pipe connection pipeline 18.

[0048] Preferably, six screw holes 4 are evenly distributed on both the perforating connection flange 3 and the connection pipeline flange 16 for partially accommodating bolts 17 to facilitate pipeline connection using bolts 17.

[0049] The outer wall of the internal liner 13 is detachably connected to the inner wall of the perforating pipe 11, facilitating the replacement of the internal liner 13. The internal liner 13 is replaced every time a simulation is carried out. The internal liner 13 is a core component of the present invention and is used to study the abrasion effect of solid proppant particles in the sand-carrying fluid on the perforation holes 2 of the wellbore during the hydraulic fracturing transformation process. By weighing the internal liner 13 before and after the simulation and taking pictures of the internal liner 13 after the simulation for observation, the abrasion effect of solid proppant particles in the sand-carrying fluid on the internal liner 13 at the perforation holes 2 of the wellbore during the hydraulic fracturing transformation process can be studied.

[0050] Preferably, the outer wall of the internal liner 13 and the inner wall of the perforating pipe 11 can be assembled and disassembled by threads.

[0051] Preferably, the internal liner 13 can be made of materials such as steel and aluminum alloy.

[0052] By observing and comparing different inner liners 13, the effects of the number of perforation clusters, cluster spacing, number of perforations, perforation diameter, and construction parameters on the perforation abrasion can be studied.

[0053] Specifically, if it is desired to obtain the effect of the perforation diameter on the perforation abrasion, only the inner diameter of the inner liner 13 needs to be changed and a simulation experiment is carried out. After the simulation experiment is completed, by comparing the abrasion degrees of different inner liners 13, the effect of the perforation diameter on the perforation abrasion can be obtained.

[0054] If it is desired to obtain the effect of the number of perforations on the perforation abrasion, only the number of perforations on the perforated wellbore 1 needs to be changed and a simulation experiment is carried out at each set number of perforations. After the simulation experiment is completed, by comparing the abrasion degrees of the inner liner 13 under different numbers of perforations, the effect of the number of perforations on the perforation abrasion can be obtained.

[0055] The perforated wellbore 1 of this embodiment includes a detachable inner liner 13. The inner liner 13 is replaced before each simulation. By observing the changes in the inner liner 13 before and after the simulation, it is beneficial to study the abrasion effect of the solid proppant particles in the sand-carrying fluid on the wellbore perforation holes 2 during the hydraulic fracturing transformation process, and it is also beneficial to study the effects of the number of perforation clusters, cluster spacing, number of perforations, perforation diameter, and construction parameters on the perforation abrasion, thereby being beneficial to providing theoretical support for the design of the fracturing plan and the analysis of the fracturing construction.

[0056] In one embodiment, the outer wall of the inner liner 13 is threadedly connected to the inner wall of the perforating pipe 11 by a thread 14.

[0057] The threaded connection 14, as a detachable connection method, is beneficial to the rapid replacement of the inner liner 13. Due to the low cost and mature manufacturing process of the threaded connection 14, it is beneficial to reduce the manufacturing cost of the inner liner 13. At the same time, the threaded connection 14 has good tightness and can avoid fluid leakage.

[0058] The perforation phase angle includes but is not limited to 60 degrees, 90 degrees, and 180 degrees.

[0059] Preferably, the inner diameter of the perforating pipe 11 is 20 mm and the outer diameter is 25 mm. The length of the perforating pipe connection pipeline 18 is 30 mm. The inner diameter of the inner liner 13 is 8 to 12 mm.

[0060] In this embodiment, the outer wall of the inner liner 13 is threadedly connected to the inner wall of the perforating pipe 11 by a thread 14, which is beneficial to the rapid replacement of the inner liner 13.

[0061] In one embodiment, as Figure 4As shown in the figure, the hole body of the inner liner 13 is a cylindrical hole 21, which is used to simulate the perforation hole 2; one end of the hole of the inner liner 13 close to the perforation connection flange 3 is a regular hexagonal prism-shaped hole 22, which is used to engage with a hexagonal wrench, so as to facilitate the installation of the inner liner 13 into the perforation pipe 11.

[0062] The cylindrical hole 21 is the research area of the simulation experiment, which is used to characterize the abrasion effect of the solid proppant particles in the sand-carrying fluid on the inner liner 13 installed at the perforation hole 2 of the wellbore during the hydraulic fracturing transformation process. The regular hexagonal prism-shaped hole 22 is used to engage with a hexagonal wrench, so that the inner liner 13 can be installed in the perforation pipe 11 labor-savingly by using the hexagonal wrench.

[0063] The height of the cylindrical hole 21 is 5 to 15 millimeters.

[0064] The cylindrical hole 21 in this embodiment is used to characterize the abrasion effect of the solid proppant particles in the sand-carrying fluid on the inner liner 13 installed at the perforation hole 2 of the wellbore during the hydraulic fracturing transformation process; the regular hexagonal prism-shaped hole 22 is used to engage with a hexagonal wrench, so that the inner liner 13 can be installed in the perforation pipe 11 labor-savingly by using the hexagonal wrench.

[0065] This embodiment also provides a combined wellbore, which includes the above-mentioned perforated wellbore 1.

[0066] Preferably, the length of the perforated wellbore 1 is 500 to 1000 millimeters, the outer diameter is 95.0 millimeters, and the inner diameter is 80.0 millimeters.

[0067] The combined wellbore of this embodiment can be used to study the abrasion effect of the solid proppant particles in the sand-carrying fluid on the inner liner 13 installed at the perforation hole 2 of the wellbore during the hydraulic fracturing transformation process, and is also beneficial to studying the influence of the number of perforation clusters, cluster spacing, hole number, hole diameter and construction parameters on the hole abrasion effect, so as to provide theoretical support for fracturing scheme design and fracturing construction analysis.

[0068] In one embodiment, the combined wellbore further includes a non-perforated wellbore 7, as Figure 2 shown, the non-perforated wellbore 7 includes a cylinder body 10, the cylinder body 10 is tubular and its two ends are provided with wellbore connection flanges 5, and the wellbore connection flanges 5 are used to connect adjacent wellbores.

[0069] There are no perforation holes 2 on the non-perforated wellbore 7, and the surface of the cylinder body 10 is smooth. The two ends of the cylinder body 10 of the non-perforated wellbore 7 are provided with wellbore connection flanges 5 for connecting adjacent wellbores, where the wellbores include the perforated wellbore 1 and the non-perforated wellbore 7. Adjacent wellbores are connected to each other through the wellbore connection flanges 5.

[0070] Preferably, the length of the non-perforated wellbore 7 is 500 to 1000 millimeters, the outer diameter is 95.0 millimeters, and the inner diameter is 80.0 millimeters.

[0071] The non-perforated wellbore 7 is an indispensable component of the combined wellbore, which is beneficial to the smooth progress of the simulation.

[0072] The non-perforated wellbore 7 of this embodiment is beneficial to the smooth progress of the simulation.

[0073] In one embodiment, the combined wellbore is a single-stage multi-cluster perforated wellbore, as Figure 5 shown, which includes perforated wellbores 1 and non-perforated wellbores 7 arranged alternately, and both ends of the combined wellbore are non-perforated wellbores 7.

[0074] Both ends of the combined wellbore are non-perforated wellbores 7, and in the middle are perforated wellbores 1 and non-perforated wellbores 7 arranged alternately, so that the combined wellbore can be used for experimental simulation as a single-stage multi-cluster perforated wellbore.

[0075] The single-stage multi-cluster perforated wellbore can be used to study the effects of the number of perforation clusters, the spacing between perforation clusters, the number of perforation holes 2, the size of perforation holes 2, etc. on the abrasion degree of the inner liner 13.

[0076] The combined wellbore of this embodiment is beneficial to studying the effects of the number of perforation clusters, the spacing between perforation clusters, the number of perforation holes 2, the size of perforation holes 2, etc. on the abrasion degree of the inner liner 13.

[0077] In one embodiment, the combined wellbore is a single-stage single-cluster perforated wellbore, as Figure 6 shown, with non-perforated wellbores 7 at both ends, and multiple perforated wellbores 1 connected end to end are arranged between the two non-perforated wellbores 7.

[0078] The single-stage single-cluster perforated wellbore is beneficial to studying the effects of the number of perforation holes 2, the perforation phase angle, the size of perforation holes 2, etc. on the abrasion degree of the inner liner 13.

[0079] This embodiment also provides a hole abrasion simulation device, which includes the above-mentioned combined wellbore.

[0080] The hole abrasion simulation device of this embodiment includes the above-mentioned combined wellbore, which can be used to study the abrasion effect of solid proppant particles in the sand-carrying fluid on the inner liner 13 installed at the perforation holes 2 of the wellbore during the hydraulic fracturing transformation process, and is also beneficial to studying the effects of the number of perforation clusters, cluster spacing, hole number, hole diameter and construction parameters, etc. on the hole abrasion effect, thereby providing a theoretical support for the design of fracturing schemes and the analysis of fracturing construction.

[0081] In one embodiment, as Figure 7As shown in the figure, the simulation device further includes: a stirring and pumping system, which is used to configure fracturing fluid, stir the fracturing fluid and proppant to form a sand-carrying fluid, and pump the evenly configured fracturing fluid or sand-carrying fluid into the combined wellbore; a reflux collection system, which is used for the reflux of liquid and the collection of proppant, and its first end is communicated with the perforating pipe connection pipeline 18 on the combined wellbore; its second end is communicated with the stirring device 35 in the stirring and pumping system, and a control system, which is used to control the operation of the simulation device and record simulation data.

[0082] The stirring and pumping system is used to obtain water, additives and proppant from the outside, configure fracturing fluid with water and additives, and can form a sand-carrying fluid by stirring the fracturing fluid and proppant, and transport the fracturing fluid or sand-carrying fluid to the inlet end of the combined wellbore.

[0083] The sand-carrying fluid enters the combined wellbore from the inlet end of the combined wellbore. When studying the influence of a small amount of proppant on the abrasion of the perforation hole 2, it is necessary to use the reflux collection system to collect the proppant in the sand-carrying fluid and reflux the fracturing fluid to the stirring device 35 in the stirring and pumping system.

[0084] When studying the influence of a large amount of proppant on the abrasion of the perforation hole 2, it is necessary to use the reflux collection system to reflux the sand-carrying fluid to the stirring device 35 in the stirring and pumping system to reuse the sand-carrying fluid.

[0085] The control system realizes the automatic control and real-time monitoring of the entire device, which ensures the automatic control of the addition amount of water and proppant, controls the flow rate of the sand-carrying fluid entering the combined wellbore, real-time monitors the readings of each flowmeter 39 and pressure gauge 40, and records relevant parameters at the same time to ensure the simulation is carried out efficiently and with high precision.

[0086] The simulation device of this embodiment can be used to simulate the influence of a small amount of proppant and a large amount of proppant on the abrasion of the internal liner 13 installed at the perforation hole 2, study the abrasion of the solid proppant particles in the sand-carrying fluid on the internal liner 13 installed at the perforation hole 2 of the wellbore during the hydraulic fracturing transformation process, and is also beneficial to studying the influence of the number of perforation clusters, cluster spacing, hole number, hole diameter and construction parameters on the hole abrasion, so as to be beneficial to providing theoretical support for fracturing scheme design and fracturing construction analysis.

[0087] In one embodiment, as Figure 7As shown, the stirring and pumping system includes: a water source 33, which is used to provide the simulation device with water required for simulation; an automatic proppant adding device 34, which is used to provide proppant to the simulation device; a stirring device 35, which is connected to the water source 33 and the automatic proppant adding device 34, and is used to configure the fracturing fluid and stir the fracturing fluid and the proppant to form a sand-carrying fluid; a large-displacement liquid injection pump 38, which is used to pump the fracturing fluid or the sand-carrying fluid and control the flow of the liquid entering the combined wellbore; a flow meter 39, which is located between the large-displacement liquid injection pump 38 and the inlet of the combined wellbore; and a pressure gauge 40, which is also located between the large-displacement liquid injection pump 38 and the inlet of the combined wellbore.

[0088] The water source 33 is used to provide water to the simulation device. A faucet or a control valve 58 is installed on the water source 33, and the water source 33 can supply water in real time. The stirring device 35 is connected to a large-displacement liquid injection pump 38, and a ball seat valve 37 is installed on the connecting pipeline 41. Before and after the experiment, the ball seat valve 37 is in a closed state. The stirring device 35 is provided with a liquid discharge outlet valve 36. When the liquid is excessive, the excess liquid can be discharged through the liquid discharge outlet valve 36. The flow meter 39 and the pressure gauge 40 are respectively used to measure the flow rate and pressure of the fracturing fluid or sand-carrying fluid entering the combined wellbore.

[0089] The configuration of fracturing fluid and the preparation of proppant include the following steps. First, the fracturing fluid is configured according to the fracturing performance requirements in the experimental scheme. By estimating the amount of fluid in the main devices and pipelines of the experimental system, the amount of fracturing fluid configuration additives is calculated according to the fluid volume and the performance parameters of the fracturing fluid in the experimental scheme, and the additives required for the experiment are weighed. After the additives are weighed, a large-capacity beaker is used to dissolve and configure the additives. After the additives are dissolved and configured, the stirring motor of the stirring device 35 is turned on, and the configured high-concentration additive liquid is added to the tank body of the stirring device 35, and stirred by the stirring motor. After stirring for 5 to 10 minutes, the large-displacement liquid injection pump 38 is turned on to circulate the fracturing fluid, and the fracturing fluid in other components and pipelines is circulated. After circulating for 10 to 15 minutes, a small amount of fracturing fluid is taken from the stirring device 35 and the viscosity is measured using a six-speed viscometer. If the performance parameters of the fracturing fluid are lower than the scheme values, the aforementioned method is continued to be used to add relevant additives until the performance of the fracturing fluid meets the scheme requirements. If the performance parameters of the fracturing fluid are higher than the performance parameters designed in the scheme, the discharge outlet valve 36 at the bottom of the stirring device 35 is opened to discharge part of the fracturing fluid as needed, and then the water source 33 is opened to continue adding part of the clean water into the stirring device 35 to configure the required fracturing fluid. After the fracturing fluid is configured, the proppant required for the experiment is added to the proppant adding device to prepare for the addition of the proppant during the experiment.

[0090] The stirring and pumping system of this embodiment can stir the fracturing fluid or the sand-carrying fluid and transport the stirred fracturing fluid or the sand-carrying fluid to the combined wellbore to ensure the smooth progress of the simulation.

[0091] In one embodiment, as Figure 7 shown, the reflux collection system includes: at least one collection device 52, which is connected to the perforated wellbore 1 for collecting proppant; and a pipeline connector 62, which is located on the pipeline connecting the collection device 52 and the mixing device 35 in the mixing and pumping system.

[0092] The collection device 52 is connected to the perforated wellbore 1 for collecting proppant. The collection device 52 is mainly used to simulate the abrasion effect of a small amount of proppant on the perforation holes 2. It is used to collect the proppant passing through the perforation holes 2 for subsequent weighing, so as to prepare for quantitative analysis.

[0093] The sand-carrying fluid flowing through the reflux collection system will enter the pipeline connector 62 and then flow to the mixing device 35 together for circulation. When simulating the abrasion effect of a small amount of proppant on the perforation holes 2, the proppant is collected by the collection device 52, and the liquid part in the sand-carrying fluid flows back to the mixing device 35 through the pipeline connector 62. When simulating the abrasion effect of a large amount of proppant on the perforation holes 2, all the sand-carrying fluid flows back to the mixing device 35 through the pipeline connector 62. A valve is provided on the connecting pipeline 41 between the pipeline connector 62 and the mixing device 35.

[0094] The reflux collection system of this embodiment can assist in realizing the reflux of the liquid and the collection of the proppant to ensure the smooth progress of the simulation.

[0095] In one embodiment, as Figure 7 shown, the collection device 52 includes: a tee 59, which is connected to the perforated pipe connecting pipeline 18; an inlet pipeline 53, which is connected to the perforated wellbore 1; and a cleaning liquid discharge port 54 for discharging the cleaning liquid.

[0096] The function of the tee 59 is to provide a flow path for the sand-carrying fluid. The sand-carrying fluid can enter the collection device 52 or bypass the collection device 52 and directly flow to the pipeline connector 62 after flowing through the tee 59. A valve is provided between the tee 59 and the collection device 52. A control valve 58 is provided between the collection device 52 and the pipeline connector 62.

[0097] When simulating the abrasion effect of a small amount of proppant on the internal liner 13 installed at the perforation hole 2, the inlet pipeline 53 is connected, the valve between the tee 59 and the collection device 52 is closed, and the control valve 58 is opened. When simulating the abrasion effect of a large amount of proppant on the perforation hole 2, the inlet pipeline 53 is closed, the valve between the tee 59 and the collection device 52 is opened, and the control valve 58 is closed. Through the above settings, it can be ensured that the collection device 52 can collect proppant when simulating the abrasion effect of a small amount of proppant on the internal liner 13 installed at the perforation hole 2, and when simulating the abrasion effect of a large amount of proppant on the internal liner 13 installed at the perforation hole 2, the proppant can bypass the collection device 52 and directly enter the pipeline connector 62 for circulating flow.

[0098] This embodiment can ensure that when simulating the abrasion effect of a small amount of proppant on the internal liner 13 installed at the perforation hole 2, the collection device 52 can collect proppant, and when simulating the abrasion effect of a large amount of proppant on the internal liner 13 installed at the perforation hole 2, the proppant can bypass the collection device 52 and directly enter the pipeline connector 62 for circulating flow, thus ensuring the smooth progress of the simulation.

[0099] In one embodiment, as Figure 7 shown, a flowmeter 39 and a pressure gauge 40 are provided on the pipeline connecting the perforation pipe connecting pipeline 18 and the collection device 52.

[0100] The flowmeter 39 and the pressure gauge 40 are respectively arranged on the pipeline connecting the perforation pipe connecting pipeline 18 and the collection device 52, and are used to measure the flow rate and pressure of the sand-carrying fluid flowing from the perforation wellbore 1 into the tee 59, so as to facilitate the real-time regulation of the simulation device by the control system.

[0101] The flowmeter 39 and the pressure gauge 40 of this embodiment are respectively used to measure the flow rate and pressure of the sand-carrying fluid flowing from the perforation wellbore 1 into the tee 59, so as to facilitate the real-time regulation of the simulation device by the control system.

[0102] In one embodiment, as Figure 7 shown, the outlet end of the combined wellbore is communicated with the pipeline connector 62.

[0103] This embodiment ensures the safety of the combined wellbore during the simulation and the cleaning of the combined wellbore after the simulation by communicating the outlet end of the combined wellbore with the pipeline connector 62.

[0104] In one embodiment, as Figure 7 shown, the control system includes a power supply 69, a controller 68 and a recording computer 72 that are communicatively connected to each other.

[0105] The power supply 69 powers the entire analog device. The controller 68 controls the operation of the analog device. The recording computer 72 records the analog data in real time. The power supply 69 is connected to each component by wires, and the controller 68 is electrically connected to the recording computer 72 by a connecting wire.

[0106] This embodiment is conducive to the automatic operation of the analog device.

[0107] In one embodiment, as Figure 7 shown, the controller 68 is communicatively connected to the proppant automatic adding device 34, the stirring device 35, the large-displacement liquid injection pump 38, each flowmeter 39, and each pressure gauge 40.

[0108] The controller 68 is communicatively connected to each component through the control wire 65 to control each component. Each flowmeter 39 and pressure gauge 40 are connected to the controller 68 through the transmission line 50.

[0109] This embodiment is conducive to the controller 68 controlling each component and collecting analog data in real time.

[0110] This embodiment also provides an analog method using the above-mentioned perforation abrasion analog device. The analog method includes the following steps: setting liquid parameters, proppant parameters, and combined wellbore parameters; the mixing and pumping system pumps the sand-carrying fluid into the combined wellbore through the inlet end of the combined wellbore. The sand-carrying fluid is the stirred fracturing fluid and proppant; part of the sand-carrying fluid flows through the inner liner 13 of the perforated wellbore 1 to reach the pipeline connector 62 and then circulates back to the stirring device 35; changing the liquid parameters, proppant parameters, and combined wellbore parameters and repeating the simulation.

[0111] Set the liquid parameters, proppant parameters, and combined wellbore parameters. The setting of the liquid parameters, proppant parameters, and combined wellbore parameters can be achieved by adjusting the water source 33, the proppant automatic adding device 34, the large-displacement liquid injection pump 38, and the configuration of the combined wellbore.

[0112] The mixing and pumping device transports the sand-carrying fluid to the combined wellbore for simulation. The combined wellbore includes a perforated wellbore 1, and the perforated wellbore 1 is configured with a detachable inner liner 13. By studying the net weight change of the inner liner 13 and taking pictures of each inner liner 13 after the simulation to study its shape change, the abrasion effect of the proppant on the perforation holes 2 can be studied.

[0113] The analog method of this embodiment can provide a feasible analog method for studying the abrasion effect of the proppant on the inner liner 13 installed at the perforation holes 2.

[0114] In one embodiment, the steps for part of the proppant-carrying fluid to flow through the inner liner 13 of the perforated wellbore 1 to reach the pipeline connector 62 and then circulate back to the mixing device 35 are as follows: The proppant-carrying fluid leaving the inner liner 13 enters the collection device 52, the collection device 52 collects the proppant, and the liquid in the proppant-carrying fluid circulates back to the mixing device 35 through the pipeline connector 62 to circulate the liquid.

[0115] When simulating the erosion effect of a small amount of proppant on the perforation holes 2 in this embodiment, the collection device 52 can collect the proppant for subsequent weighing, so as to prepare for quantitative analysis.

[0116] In one embodiment, the steps for part of the proppant-carrying fluid to flow through the inner liner 13 of the perforated wellbore 1 to reach the pipeline connector 62 and then circulate back to the mixing device 35 are as follows: The proppant-carrying fluid leaving the inner liner 13 directly flows into the pipeline connector 62 through the pipeline to circulate the liquid and the proppant.

[0117] When simulating the erosion effect of a large amount of proppant on the inner liner 13 installed at the perforation holes 2 in this embodiment, the proppant can bypass the collection device 52 and directly enter the pipeline connector 62 for circulating flow, so as to ensure the smooth progress of the simulation.

[0118] In one embodiment, each inner liner 13 is numbered and its corresponding position and the experimental simulation serial number are recorded; the net weight of each inner liner 13 is weighed before and after the simulation, and each inner liner 13 is photographed after the simulation to study its shape change.

[0119] In order to better quantitatively and qualitatively study the changes of the inner liner 13 before and after the simulation, it is necessary to number each inner liner 13 and record its corresponding position and the experimental simulation serial number; the net weight of each inner liner 13 is weighed before and after the simulation, and each inner liner 13 is photographed after the simulation to study its shape change, which is beneficial to improving the accuracy of the simulation results.

[0120] This embodiment is beneficial to improving the accuracy of the simulation results.

[0121] Example 1

[0122] First, prepare a combined wellbore, and splice a perforated wellbore 1 and a non-perforated wellbore 7 of a certain specification in a certain way. The combined wellbore can be a single-segment multi-cluster perforated wellbore or a single-segment single-cluster perforated wellbore. The number of perforation clusters, the perforation cluster spacing, the number of perforation holes 2, the size of the perforation holes 2, etc. can all be selected according to needs.

[0123] The new inner liner 13 is detachably installed into the perforation holes 2 of the perforated wellbore 1. Preferably, the installation method can be threaded connection 14 to facilitate the replacement of the inner liner 13 after each simulation.

[0124] The assembly of the simulation device includes the following steps.

[0125] Installation of the fluid flow pipeline.

[0126] First, connect the stirring device 35 to the water source 33. A faucet or control valve 58 is installed on the water source 33, and the water source 33 can supply water in real time.

[0127] Next, connect the stirring device 35 and the large-displacement liquid injection pump 38. A ball seat valve 37 is installed on the pipeline. Before and after the simulation, the ball seat valve 37 is in the closed state.

[0128] Then, connect the large-displacement liquid injection pump 38 and the combined wellbore. One end of the connecting pipeline 41 is connected to the large-displacement liquid injection pump 38, and the other end of the connecting pipeline 41 is flange-connected to the combined wellbore front-end connecting flange 26 of the combined wellbore. A flow meter 39 and a pressure gauge 40 are provided on the connecting pipeline 41 connecting the large-displacement liquid injection pump 38 and the combined wellbore, for monitoring the flow rate and pressure of the sand-carrying fluid entering the combined wellbore.

[0129] Then, the combined wellbore rear-end connecting flange 27 at the tail end of the combined wellbore is communicated with the pipeline connector 62 through the connecting pipeline 41. A ball seat valve 37 is installed on the connecting pipeline 41 between the combined wellbore rear-end connecting flange 27 and the pipeline connector 62. During the normal simulation process, the ball seat valve 37 is in the closed state. During the special simulation process or when the combined wellbore needs to be cleaned, the ball seat valve 37 is opened.

[0130] Then, use the connecting pipeline 41 to connect the perforating pipe 11 and the collection device 52, and then connect each device between the collection device 52 and the pipeline connector 62. A control valve 58 is installed on the inlet pipeline 53 of the collection device 52. A tee 59 is provided at one end of the control valve 58 close to the perforating pipe 11. The tee 59 is respectively communicated with the perforating pipe 11, the collection device 52 and the pipeline connector 62. Ball seat valves 37, flow meters 39 and pressure gauges 40 are provided on the pipeline between the perforating pipe 11 and the collection device 52. The collection device 52 is connected to the pipeline, and a ball seat valve 37 is installed on the pipeline. A ball seat type control valve 58 is installed on the pipeline between the collection device 52 and the pipeline connector 62.

[0131] Installation of the control system.

[0132] First, use the control wire 65 to connect the proppant automatic adding device 34 and the controller 68. The control wire 65 is connected to the motor of the proppant automatic adding device 34 to control the rotation speed of the motor, so as to control the addition amount of the proppant per unit time.

[0133] Next, connect the controller 68 and the stirring device 35 with the control wire 65. The control wire 65 is connected to the stirring motor of the stirring device 35 to control the rotation speed of the stirring motor, so as to stir different liquids and proppants to make them mix evenly.

[0134] Then, connect the controller 68 and the large-displacement liquid injection pump 38 with the control wire 65, and adjust the injection displacement of the large-displacement liquid injection pump 38 by adjusting the current frequency.

[0135] Then, connect the controller 68 and each flowmeter 39 and pressure gauge 40 with the transmission line 50. The controller 68 converts the signals of each flowmeter 39 and pressure gauge 40 and transmits them to the recording computer 72.

[0136] Then, connect the controller 68 and the recording computer 72.

[0137] Finally, connect the controller 68 and the main power supply 69 with the high-power line 70, so that the main power supply 69 supplies power to the controller 68 and related components.

[0138] After the assembly is completed, the sealing performance of the simulation device needs to be tested, and the sealing test steps are as follows.

[0139] First, adjust each valve. Open the valve between the pipeline connector 62 and the stirring device 35, close the drain outlet valve 36 at the bottom of the stirring device 35, close the valve at the cleaning liquid drain outlet 54, and open each valve on the pipeline loop to form a circulation loop for the fluid in the simulation device. Among them, each valve on the pipeline loop includes the ball seat valve 37 on the pipeline between the stirring device 35 and the large-displacement liquid injection pump 38, the ball seat valve 37 between each perforation pipe 11 and the collection device 52, the control valve 58 between the collection device 52 and the pipeline connector 62, the ball seat valve 37 between the end of the combined wellbore and the pipeline connector 62, etc.

[0140] Next, inject clean water into the simulation device. Open the switch or valve of the water source 33, and inject water into the stirring device 35 through the water source 33. The clean water flows along the pipeline into components such as the large-displacement liquid injection pump 38, the combined wellbore, and the collection device 52. When each main component is filled with water, close the water source 33, and no more clean water is injected into the simulation system.

[0141] During the water injection process, observe the sealing condition of the pipeline in real time and check whether the pipeline leaks.

[0142] In order to further test the sealing performance of the simulation device, start the large-displacement liquid injection pump 38 through the controller 68, and use the large-displacement liquid injection pump 38 to conduct a sealing test under high displacement. During the test, gradually increase the displacement to the design value and observe the sealing performance of the experimental system loop.

[0143] After the sealing performance test is completed, pre-simulation preparations need to be carried out. The main pre-simulation preparation work is the preparation of fracturing fluid and proppant.

[0144] First, configure the liquid according to the liquid performance requirements in the experimental plan. By estimating the fluid volume in the main devices and pipelines of the experimental system and based on the fluid volume and the liquid performance parameters in the experimental plan, calculate the amount of additives for liquid configuration, and weigh the additives required for the experiment. After the additives are weighed, use a large-capacity beaker to dissolve and configure the additives. After the liquid is completely dissolved and configured, turn on the stirring motor of the stirring device 35, add the configured high-concentration additive liquid to the tank body of the stirring device 35, and use the stirring motor to stir. After stirring for 5 to 10 minutes, turn on the large-displacement liquid injection pump 38 to circulate the liquid, circulate the liquid in other components and pipelines, and after circulating for 10 to 15 minutes, take a small amount of liquid from the stirring device 35 and measure the viscosity using a six-speed viscometer. If the liquid performance parameters are lower than the planned values, continue to add relevant additives using the aforementioned method until the liquid performance meets the plan requirements. If the liquid performance parameters are higher than the performance parameters designed in the plan, open the drain outlet valve 36 at the lower part of the stirring device 35, drain part of the liquid as needed, then open the water source 33, and continue to add some clear water into the stirring device 35 to configure the required liquid. After the liquid configuration is completed, add the proppant required for the experiment to the proppant addition device for use during the experiment.

[0145] Simulation test.

[0146] According to the simulation experiment plan, study the influence of proppant on the abrasion of the inner liner 13 installed at the perforation hole 2. Adjust each valve to adjust the experimental displacement of the large-displacement liquid injection pump 38 to the flow value designed in the simulation plan, and adjust the flow values of all perforation pipes 11. Keep the flow stable for 5 to 10 minutes.

[0147] After the flow of each pipeline is stable, according to the simulation experiment plan, add proppant to the stirring device 35 through the proppant addition device. The proppant is mixed with the liquid in the stirring device 35 and injected into the combined wellbore through the large-displacement liquid injection pump 38, and the sand-carrying fluid abrades the inner surface of the inner liner 13 through the perforation pipe 11.

[0148] Observation of simulation results is the key step of this simulation. According to the simulation plan, after the injection volumes of the liquid and proppant reach the designed amounts, first, through the controller 68, turn off the proppant automatic addition device 34, the large-displacement liquid injection pump 38, and the stirring device 35, and at the same time close each ball seat valve 37 to close the fluid pipeline loop in the simulation device.

[0149] After discharging the sand-carrying fluid or fracturing fluid in the combined wellbore, disassemble all the pipelines connected to the perforating pipe 11, and take out the inner liner 13 inside the perforating pipe 11. Observe the shape change of the inner liner 13, and at the same time take pictures of the inner liner 13 using a camera; and weigh the net weight of each inner liner 13 before and after the simulation, so as to study the abrasion effect of the proppant on the perforation holes 2.

[0150] For the analysis of the simulation results, it is necessary to confirm its group, namely parameters such as the simulation environment and position, according to the experimental simulation serial number of each inner liner 13, and then analyze the abrasion results of the perforation holes 2 based on the shape and weight change rules of the inner liner 13 to clarify the abrasion change rules of the perforation holes 2.

[0151] Example Two

[0152] On the basis of Example One, this example mainly simulates the abrasion of a small amount of proppant on the perforation holes 2. It mainly uses the collection device 52 to collect the proppant flowing through the perforating pipe 11 for subsequent weighing, so as to prepare for quantitative analysis.

[0153] To achieve the above simulation goal, it is necessary to open the inlet pipelines 53 of all the collection devices 52 and close the ball seat valve 37 behind the tee 59. The sand-carrying fluid enters the collection device 52 through the perforating pipe 11 and the perforating pipe connection pipeline 18. The proppant in the sand-carrying fluid is collected by the collection device 52, and the liquid in the sand-carrying fluid flows into the pipeline connector 62.

[0154] This example is used to simulate the abrasion of a small amount of proppant on the inner liner 13 installed at the perforation holes 2.

[0155] Example Three

[0156] On the basis of Example One, this example mainly simulates the abrasion of a large amount of proppant on the inner liner 13 installed at the perforation holes 2.

[0157] To achieve the above simulation goal, it is necessary to close the inlet pipelines 53 of all the collection devices 52 and open the ball seat valve 37 behind the tee 59. The sand-carrying fluid bypasses the collection device 52 through the perforating pipe 11 and the perforating pipe connection pipeline 18 and directly flows into the pipeline connector 62.

[0158] This example is used to simulate the abrasion of a large amount of proppant on the perforation holes 2.

[0159] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "bottom", "top", "front", "rear", "inner", "outer", "left", "right", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0160] Although the present invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed, as long as they do not depart from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the different dependent claims and the features described herein can be combined in a manner different from that described in the original claims. It should also be understood that the features described in connection with a single embodiment can be used in other described embodiments.

Claims

1. A perforated wellbore, characterized in that, it includes: a cylinder body, which is tubular, and wellbore connection flanges are provided at both ends of the cylinder body, and the wellbore connection flanges are used to connect adjacent wellbores; a perforating pipe, which is arranged on the cylinder body, the first end of the perforating pipe is communicated with the inside of the cylinder body through perforation holes, and a perforating connection flange is formed at the second end thereof, and the perforating connection flange is used to connect with a connection pipeline flange of a perforating pipe connection pipeline so as to communicate the perforating pipe with the perforating pipe connection pipeline; and, an internal lining pipe, the outer wall of which is detachably connected to the inner wall of the perforating pipe; wherein, the hole body of the internal lining pipe is a cylindrical hole for simulating a perforation hole; one end of the hole of the internal lining pipe close to the perforating connection flange is a regular hexagonal prism-shaped hole for engaging with a hexagonal wrench so as to install the internal lining pipe in the perforating pipe; in the radial cross-section of the internal lining pipe, the projection of the cylindrical hole completely falls within the projection of the regular hexagonal prism-shaped hole.

2. The perforated wellbore according to claim 1, characterized in that, the outer wall of the internal lining pipe is threadedly connected to the inner wall of the perforating pipe.

3. A combined wellbore, characterized in that, it includes the perforated wellbore according to any one of claims 1 to 2.

4. The combined wellbore according to claim 3, characterized in that, it further includes a non-perforated wellbore, and the non-perforated wellbore includes a cylinder body, the cylinder body is tubular and wellbore connection flanges are provided at both ends thereof, and the wellbore connection flanges are used to connect adjacent wellbores.

5. The combined wellbore according to claim 4, characterized in that, the combined wellbore is a single-section multi-cluster perforated wellbore, which includes the perforated wellbore and the non-perforated wellbore arranged alternately, and both ends of the combined wellbore are the non-perforated wellbores.

6. The combined wellbore according to claim 4, characterized in that, the combined wellbore is a single-section single-cluster perforated wellbore, both ends thereof are the non-perforated wellbores, and a plurality of the perforated wellbores connected end to end are arranged between the two non-perforated wellbores.

7. A hole erosion simulation device, characterized in that, it includes the combined wellbore according to any one of claims 3 to 6.

8. The hole erosion simulation device according to claim 7, characterized in that, it further includes: a stirring and pumping system, which is used to configure fracturing fluid and stir the fracturing fluid and proppant to form a sand-carrying fluid and pump the configured and uniform fracturing fluid or sand-carrying fluid to the combined wellbore; a reflux collection system for liquid reflux and proppant collection, its first end is communicated with the perforating pipe connection pipeline on the combined wellbore; its second end is communicated with the stirring device in the stirring and pumping system, and, a control system for controlling the operation of the simulation device and recording simulation data.

9. The hole erosion simulation device according to claim 8, characterized in that, the stirring and pumping system includes: a water source for providing water required for simulation to the simulation device; a proppant automatic adding device for providing proppant to the simulation device; A stirring device, which is connected to a water source and a proppant automatic adding device, and is used for configuring fracturing fluid, stirring the fracturing fluid and proppant to form a sand-carrying fluid; A high-capacity liquid injection pump, which is used for pumping the fracturing fluid or the sand-carrying fluid and controlling the flow rate of the liquid entering the combined wellbore; A flowmeter, which is located between the high-capacity liquid injection pump and the inlet of the combined wellbore; and A pressure gauge, which is also located between the high-capacity liquid injection pump and the inlet of the combined wellbore.

10. The perforation abrasion simulation device according to claim 9, characterized in that the reflux collection system includes: at least one collection device, which is connected to the perforation wellbore and is used for collecting proppant; and A pipeline connector, which is located on the pipeline connecting the collection device and the stirring device in the stirring and pumping system.

11. The perforation abrasion simulation device according to claim 10, characterized in that the collection device includes: A tee, which is connected to the perforation pipe connection pipeline; An inlet pipeline, which is connected to the perforation wellbore; and A cleaning liquid discharge port, which is used for discharging residual liquid or cleaning liquid.

12. The perforation abrasion simulation device according to claim 10, characterized in that A flowmeter and a pressure gauge are arranged on the pipeline connecting the perforation pipe connection pipeline and the collection device.

13. The perforation abrasion simulation device according to claim 10, characterized in that The outlet end of the combined wellbore is connected to the pipeline connector.

14. The perforation abrasion simulation device according to claim 10, characterized in that The control system includes a power supply, a controller and a recording computer that are communicatively connected to each other.

15. The perforation abrasion simulation device according to claim 14, characterized in that The controller is communicatively connected to the proppant automatic adding device, the stirring device, the high-capacity liquid injection pump, each flowmeter and each pressure gauge.

16. A simulation method using the perforation abrasion simulation device according to any one of claims 10 to 15, characterized in that includes the following steps: Setting liquid parameters, proppant parameters and combined wellbore parameters; The stirring and pumping system pumps the sand-carrying fluid into the combined wellbore through the inlet end of the combined wellbore, and the sand-carrying fluid is the stirred fracturing fluid and proppant; Part of the sand-carrying fluid flows through the inner liner of the perforation wellbore to reach the pipeline connector and then circulates back to the stirring device; Changing the liquid parameters, proppant parameters and combined wellbore parameters and repeating the simulation.

17. The simulation method according to claim 16, characterized in that Part of the sand-carrying fluid flows through the inner liner of the perforation wellbore to reach the pipeline connector and then circulates back to the stirring device includes the following steps: The sand-carrying fluid leaving the inner liner enters the collection device, the collection device collects the proppant, and the fracturing fluid in the sand-carrying fluid circulates back to the stirring device through the pipeline connector to circulate the fracturing fluid.

18. The simulation method according to claim 16, characterized in that Part of the sand-carrying fluid flows through the inner liner of the perforation wellbore to reach the pipeline connector and then circulates back to the stirring device includes the following steps: The sand-carrying fluid leaving the inner liner directly flows into the pipeline connector through the pipeline to circulate the sand-carrying fluid.

19. The simulation method according to any one of claims 16 to 18, It is characterized in that each of the internal liners is labeled and its corresponding position and experimental simulation serial number are recorded; the net weight of each of the internal liners is weighed before and after the simulation, and each of the internal liners is photographed after the simulation to study its shape change.

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