Simulation device of radial well system and test method thereof

Abstract

The invention provides a simulation device of a radial well system and a test method thereof.The simulation device comprises a simulation barrel, a simulation shaft and at least one simulation diameter well, a simulation space used for containing a simulation stratum is defined in the simulation barrel, at least part of the simulation shaft is arranged in the simulation stratum, and a pressurization channel is further defined in the simulation shaft; the simulation diameter well is connected to the simulation shaft and located in the simulation stratum, a simulation channel communicated with the pressurization channel is defined in the simulation diameter well, and a plurality of jet flow holes used for communicating the simulation space with the simulation channel are formed in the simulation diameter well. According to the simulation device, test verification of theoretical analysis of the influence of radial well setting parameters on the injection-production effect can be effectively achieved under the ground test condition, the influence of drilling parameters on the injection-production effect is objectively explained from the test way, and a foundation is laid for further research and development of the radial drilling technology; reasonable guidance is provided for field application of the radial drilling technology, and the test research blank is filled up.

Description

Technical Field

[0001] This application relates to oil development and production engineering technology, and in particular to a simulation device and test method for a radial well system. Background Technology

[0002] Currently, the number of old and depleted wells in oilfields entering the mid-to-late stages of development is constantly increasing, while newly proven reserves are severely insufficient. Some reservoirs are low-permeability, heavy oil, thin oil layers, and fractured oil and gas reservoirs. For low-yield and low-permeability tight oil layers, conventional perforation methods are often insufficient to accurately determine reservoir pressure, fluid properties, and other parameters due to short penetration distances and near-wellbore contamination. The development of old oilfields also faces challenges such as high water injection pressure and low recovery rates in marginal wells.

[0003] Radial drilling technology is an extension of side-drilling micro-bore technology. It can use specialized downhole tools to achieve in-casing turning and drill multiple radial micro-horizontal holes at different locations and directions in the formation. This improves the permeability of low-permeability oil layers, removes near-wellbore contamination, and significantly increases the reservoir drainage area, thereby achieving the goals of connecting formations, improving well networks, and enhancing the injection and production capacity of oil and gas fields.

[0004] Radial borehole parameters mainly include borehole diameter, borehole length, borehole density, and borehole direction. It is generally believed that borehole parameters have a significant impact on improving the injection and production capacity of oil and gas fields. However, most research in this area relies on software simulations, lacking practicality, reliability, and credibility. Therefore, a reasonable and reliable experimental setup is needed for verification, objectively demonstrating the impact of borehole parameters on injection and production effects through experimental methods. Summary of the Invention

[0005] This invention provides a simulation device for a radial well system, which can experimentally verify the impact of radial well setup parameters on injection and production performance under ground test conditions. It objectively illustrates the impact of radial well setup parameters on injection and production performance through experimental means, and provides more accurate and reliable technical guidance for the research and design of radial well systems.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] This invention provides a simulation device for a radial well system, comprising: a simulation cylinder defining a simulation space for accommodating a simulated formation; a simulation wellbore, at least a portion of which is disposed within the simulated formation within the simulation cylinder, and a pressurization channel defined within the simulation wellbore; at least one simulation radial well connected to the simulation wellbore and extending at an angle relative to the axial direction of the simulation wellbore, the simulation radial well being located within the simulated formation within the simulation cylinder, the simulation radial well defining a simulation channel communicating with the pressurization channel, and a plurality of jet holes provided on the simulation radial well for communicating the simulation space and the simulation channel; the simulation device is configured to: introduce test fluid into the pressurization channel, so that the test fluid permeates into the simulated formation within the simulation space through the simulation channel and the plurality of jet holes.

[0008] As one possible implementation, the simulation cylinder has multiple seepage holes for connecting the simulation space with the external environment of the simulation cylinder, so that the test fluid in the simulated formation can seep out through the multiple seepage holes.

[0009] As one possible implementation, when there are multiple simulated wells, the multiple simulated wells are arranged at intervals along the length direction of the simulated wellbore; when there are multiple simulated wells, the multiple simulated wells are arranged at intervals along the circumference of the simulated wellbore; or, when there are multiple simulated wells, the multiple simulated wells are arranged at intervals along the length direction of the simulated wellbore and along the circumference of the simulated wellbore.

[0010] As one possible implementation, the simulation device further includes: a protective cylinder defining an upwardly open receiving space; the simulation cylinder is disposed within the receiving space, and the simulation cylinder has multiple seepage holes for connecting the simulation space and the receiving space, so that test fluid in the simulated formation can seep into the receiving space through the multiple seepage holes.

[0011] As one possible implementation, a drain hole is provided at the bottom of the protective cylinder, which connects the containment space with the external environment of the protective cylinder to drain the test fluid in the containment space.

[0012] As one possible implementation, the simulation device further includes a cover connected to the protective cylinder and located at the opening of the containment space to close the containment space and the simulation space.

[0013] As one possible implementation, the cover has a through hole; the simulated wellbore has a casing that passes through the through hole so that a section of the casing is outside the simulated wellbore, and the first port of the casing located outside the simulated wellbore is used to introduce test fluid.

[0014] As one possible implementation, the simulated wellbore further includes: a pressure fitting disposed at the first port of the casing for connecting to the test fluid; and a plug plate disposed at the second port of the casing opposite to the first port for sealing the second port of the casing.

[0015] As one possible implementation, the simulation device further includes a pressurizing pump, the outlet of which is connected to the simulated wellbore to introduce test fluid into the pressurizing channel, and a flow detection unit is provided on the pressurizing pump to detect the flow rate of the test fluid.

[0016] The present invention also provides a test method for a simulation device of a radial well system. This test method uses any of the simulation devices described above. The test method includes: providing multiple simulation devices, wherein in the multiple simulation devices, one of the simulated radial well settings is configured as a variable parameter, and the remaining settings are configured as quantitative parameters. The settings include the density of the simulated radial well, the length of the simulated radial well, the orientation of the simulated radial well, and the inner diameter of the simulated radial well; introducing test fluid with the same preset pressure value into the pressurization channels of the multiple simulation devices; detecting the flow rate of the test fluid in the multiple simulation devices; and deriving the relationship between the variable parameter and formation permeability based on the flow rate of the test fluid.

[0017] The simulation device of this invention defines a simulation space within a simulation cylinder to accommodate a simulated formation. At least a portion of the simulation wellbore is located within the simulated formation. A pressurized channel is also defined within the simulation wellbore. A simulated radial well is connected to the simulation wellbore and located within the simulated formation. The simulated radial well has a simulated channel communicating with the pressurized channel. Multiple jet holes are provided on the simulated radial well to connect the simulation space and the simulated channel. Test fluid is introduced into the pressurized channel within the simulation wellbore. The test fluid enters the simulated channel of the simulated radial well from the pressurized channel, then flows into the simulated formation from the multiple jet holes of the simulated radial well, and finally seeps out from the simulated formation. This allows for the verification of the impact of different settings of the simulated radial well on the simulated formation based on the flow rate of the test fluid, thereby enabling the verification of the impact of radial well settings on injection and production effects. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the simulation device in one embodiment of the present invention;

[0020] Figure 2This is a schematic diagram showing the connection relationship between the simulated wellbore and the simulated caliper in a simulation device according to one embodiment of the present invention;

[0021] Figure 3 This is a control principle for using a simulation device in one embodiment of the present invention. Figure 1 ;

[0022] Figure 4 This is a control principle for using a simulation device in one embodiment of the present invention. Figure 2 ;

[0023] Figure 5 This is a control principle for using a simulation device in one embodiment of the present invention. Figure 3 ;

[0024] Figure 6 This is a control principle for using a simulation device in one embodiment of the present invention. Figure 4 ;

[0025] Figure 7 This is a flowchart of an experimental method in one embodiment of the present invention.

[0026] Explanation of reference numerals in the attached figures:

[0027] 100 - Simulated cylinder; 110 - Simulated space; 120 - Water seepage hole;

[0028] 200 - Simulated wellbore; 210 - Pressurization channel; 220 - Casing; 230 - Pressurization connector; 240 - Plug plate;

[0029] 300 - Simulated wellbore; 310 - Simulated channel; 320 - Jet orifice;

[0030] 400 - Simulated formation;

[0031] 500 - Protective cylinder; 510 - Accommodation space; 520 - Drain hole;

[0032] 600 - Cover body; 610 - Through hole;

[0033] 700-Pressure pump; 710 Flow detection unit. Detailed Implementation

[0034] Radial well drilling technology is an effective technique for enhancing oil well production. During the initial design phase, it is necessary to study the impact of radial well design parameters on injection and production efficiency in order to rationally design these parameters. Currently, the study of the impact of radial well design parameters on injection and production efficiency is mostly accomplished through software simulation. However, results obtained solely from software simulation lack practicality and reliability, making it difficult to provide a reliable guarantee for subsequent design research.

[0035] In view of this, the present invention provides a simulation device for a radial well system, which can simulate the relationship between various design parameters and the improvement of formation permeability by radial wells in the laboratory, providing a reliable guarantee for subsequent design studies.

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] See Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of the simulation device in one embodiment of the present invention. Figure 2 This is a schematic diagram illustrating the connection relationship between the simulated wellbore 200 and the simulated radial well 300 in a simulation device according to one embodiment of the present invention. The present invention first provides a simulation device for a radial well system, which can simulate a radial well system in the laboratory and effectively realize the theoretical analysis and experimental verification of the influence of radial drilling parameters on injection and production effects.

[0038] The simulation device may include a simulation cylinder 100, a simulation wellbore 200, and at least one simulation borehole 300. The simulation cylinder 100 defines a simulation space 110 for accommodating a simulated formation 400. At least a portion of the simulation wellbore 200 is disposed within the simulated formation 400, and a pressurization channel 210 is also defined within the simulation wellbore 200. At least one simulation borehole 300 is connected to the simulation wellbore 200 and extends at an angle relative to the axial direction of the simulation wellbore 200. The simulation borehole 300 is located within the simulated formation 400 within the simulation cylinder 100, and a simulation channel 310 communicating with the pressurization channel 210 is defined within the simulation borehole 300. The simulation borehole 300 has a plurality of jet holes 320 for connecting the simulation space 110 and the simulation channel 310. The simulation device is configured to introduce test fluid into the pressurized channel 210 so that the test fluid can penetrate into the simulated formation 400 in the simulation space 110 through the simulation channel 310 and multiple jet holes 320.

[0039] The simulated stratum 400 is used to simulate actual geological formations. In some specific embodiments, the simulated stratum 400 is solidified using cement mortar made from a mixture of ordinary building sand, cement, clay, and water in a certain proportion to simulate the various properties of rock as closely as possible. The proportions of the above components can be adjusted according to the composition of the actual geological formation.

[0040] The simulated wellbore 200 is used to simulate the production of casing in a downhole well. In some specific embodiments, the simulated wellbore 200 may be configured as a cylindrical tube and installed vertically.

[0041] The simulated radial well 300 is used to simulate a radial well. In some specific embodiments, the simulated radial well 300 may be configured to extend radially along the simulated wellbore 200, that is, the simulated radial well 300 extends at a 90° angle relative to the axial direction of the simulated wellbore 200. In some other specific embodiments, the simulated radial well 300 may also be configured to extend upward or downward relative to the axial direction of the simulated wellbore 200. The number of simulated radial wells 300 may be one or more, depending on the specific experimental method.

[0042] In some further embodiments, the simulation device may include a pressurization pump 700, the outlet of which is connected to the simulated wellbore 200 to introduce test fluid into the pressurization channel 210.

[0043] When making the simulation device, first prepare a well steel pipe, and weld the lower end of the well steel pipe closed with a plug plate 240 to form a blind end; according to the experimental scenario (the location, diameter and number of simulated wells 300, etc.), drill holes in the well steel pipe to connect to the simulated wells 300, and complete the construction of the simulated well 200.

[0044] Secondly, prepare a duct steel pipe as a simulated diameter well 300, and the small holes on the duct steel pipe can be used as jet holes 320. Weld a blind end plug steel plate to one end of the duct steel pipe, and weld the other end to the drill hole on the well barrel steel pipe to complete the connection between the simulated diameter well 300 and the simulated well barrel 200.

[0045] Next, prepare the simulated cylinder 100 and cement mortar. Place the connected simulated well cylinder 200 and simulated borehole 300 in the designed positions on the mold. Inject cement mortar into the mold and allow it to set, paying attention to water curing during this period. After solidification, remove the mold and place the solidified simulated well cylinder 200, simulated borehole 300, and simulated cylinder 100 into the simulated cylinder 100. It is important to note that during grouting, the jet holes 320 on the simulated borehole 300 should ensure that cement mortar does not pass through as much as possible or only a small amount passes through; otherwise, the jet holes 320 will become clogged, affecting the simulation effect. Specifically, during construction, a filter screen can be laid on the outside of the simulated borehole 300 to ensure that cement mortar does not pass through as much as possible or only a small amount passes through.

[0046] Finally, the upper end of the simulated wellbore 200, which protrudes from the simulated cylinder 100, is connected to the pressurization pump 700 to introduce test fluid into the pressurization channel 210. In some specific embodiments, the test fluid may be water.

[0047] Radial drilling technology is an extension of sidetracking micro-bore technology. It utilizes specialized downhole tools to achieve in-casing reversal, drilling multiple radial micro-horizontal boreholes at different locations and directions within the formation. This improves the permeability of low-permeability oil-bearing layers, removes near-wellbore contamination, significantly increases reservoir drainage area, and achieves goals such as connecting formations, improving well networks, and enhancing oil and gas field injection and production capabilities. However, due to the complex and variable geological conditions of the formations, the impact of radial well setup parameters on the permeability of permeable layers is unpredictable when extending radial wells in different regions. Therefore, reasonable and reliable experimental research methods are needed for verification.

[0048] In this embodiment of the simulation device, the test fluid is introduced into the pressurized channel 210 inside the simulated wellbore 200. The test fluid enters the simulated channel 310 of the simulated borehole 300 from the pressurized channel 210, and then flows into the simulated formation 400 from the multiple jet holes 320 of the simulated borehole 300, and finally seeps out from the simulated formation 400. In this way, the relationship between the permeability of the simulated borehole 300 and the simulated formation 400 with different settings can be verified according to the flow rate of the test fluid.

[0049] The working principle will be explained by listing several experiments below.

[0050] See Figure 3 , Figure 3 This is a control principle for using a simulation device in one embodiment of the present invention. Figure 1 Experiment 1—Verifying the relationship between radial well diameter and formation permeability.

[0051] The verification test can be conducted according to the following steps:

[0052] Multiple simulation devices are provided, with the diameter of the simulated well 300 set differently in each device, while other parameters (length, quantity, density, position, orientation, etc. of each component) remain the same. To improve the reliability of the test data, the number of simulation devices can be set to more than two, such as three or four. For example, as shown in Figures (3a), (3b), and (3c), the diameters of the simulated well 300 are set to d1, d2, and d3, which decrease sequentially.

[0053] Test fluid with the same preset pressure value is introduced into the pressurization channel 210 of multiple simulation devices.

[0054] The flow rate of the test fluid is detected in multiple simulation devices. In some specific embodiments, the pressure pump 700 is equipped with a flow detection unit 710 for detecting the flow rate of the test fluid.

[0055] The relationship between the diameter of the simulated wellbore 300 and the formation permeability was determined based on the flow rate of the test fluid. Since the flow rate of the test fluid is positively correlated with the permeability of the simulated formation 400, the relationship between the diameter of the simulated wellbore 300 and the permeability of the simulated formation 400 was obtained by comparing the flow rates of specimens with different simulated wellbore 300 diameters, which is also the relationship between the diameter of the radial well and the permeability of the actual formation.

[0056] See Figure 4 , Figure 4 This is a control principle for using a simulation device in one embodiment of the present invention. Figure 2 Experiment 2—Verifying the relationship between radial well length and formation permeability.

[0057] The verification test can be conducted according to the following steps:

[0058] Multiple simulation devices are provided, with the length of the simulated wellbore 300 varying across these devices, while other parameters (diameter, number, density, position, orientation, etc. of each component) remain identical. To improve the reliability of the test data, the number of simulation devices can be greater than two, such as three or four groups. For example, as shown in Figures (4a), (4b), and (4c), the lengths of the simulated wellbore 300 are set to L1, L2, and L3, which decrease sequentially.

[0059] Test fluid with the same preset pressure value is introduced into the pressurization channel 210 of multiple simulation devices.

[0060] The flow rate of the test fluid is detected in multiple simulation devices.

[0061] The relationship between the length of the simulated radial well 300 and the formation permeability was determined based on the flow rate of the test fluid. Since the flow rate of the test fluid is positively correlated with the permeability of the simulated formation 400, the relationship between the length of the simulated radial well 300 and the permeability of the simulated formation 400 was obtained by comparing the flow rates of specimens with different lengths of simulated radial well 300, which is also the relationship between the length of the radial well and the permeability of the actual formation.

[0062] See Figure 5 , Figure 5 This is a control principle for using a simulation device in one embodiment of the present invention. Figure 3 Experiment 3—Verifying the relationship between density and formation permeability in radial wells.

[0063] The verification test can be conducted according to the following steps:

[0064] Multiple simulation devices are provided, with different densities of the simulated borehole 300 in each device, while keeping other parameters (diameter, quantity, position, orientation, etc. of each component) the same. To improve the reliability of the test data, the number of simulation devices can be greater than two, such as three or four. It should be noted that the density of the simulated borehole 300 can be understood as the tightness of the simulated borehole 300 along the axial direction of the simulated wellbore 200, and can be measured by setting the number of simulated boreholes 300 per unit length along the axial direction of the simulated wellbore 200. To improve the reliability of the test data, the number of simulation devices can be greater than two, such as three or four. For example, as shown in Figures (5a), (5b), and (5c), the density of the simulated borehole 300 is set to decrease sequentially.

[0065] Test fluid with the same preset pressure value is introduced into the pressurization channel 210 of multiple simulation devices.

[0066] The flow rate of the test fluid is detected in multiple simulation devices.

[0067] The relationship between the density of the simulated wellbore 300 and the permeability of the simulated formation 400 was determined based on the flow rate of the test fluid. Since the flow rate of the test fluid is positively correlated with the permeability of the simulated formation 400, the relationship between the density of the simulated wellbore 300 and the permeability of the simulated formation 400 was obtained by comparing the flow rates of density specimens of different simulated wellbore 300, which is also the relationship between the density of the radial well and the permeability of the actual formation.

[0068] See Figure 6 , Figure 6 This is a control principle for using a simulation device in one embodiment of the present invention. Figure 4 Experiment 4—Verifying the relationship between radial well orientation and formation permeability.

[0069] The verification test can be conducted according to the following steps:

[0070] Multiple simulation devices are provided, with the orientation of the simulated well 300 in each device set differently, while other parameters (diameter, number, density, position, etc. of each component) remain the same. To improve the reliability of the test data, the number of simulation devices can be set to more than two groups, such as three or four groups. For example, as shown in Figures (6a), (6b), and (6c), the orientation of the simulated well 300 is set to left, forward, and right respectively.

[0071] Test fluid with the same preset pressure value is introduced into the pressurization channel 210 of multiple simulation devices.

[0072] The flow rate of the test fluid is detected in multiple simulation devices.

[0073] The relationship between the orientation of the simulated radial well 300 and the permeability of the simulated formation 400 was determined based on the flow rate of the test fluid. Since the flow rate of the test fluid is positively correlated with the permeability of the simulated formation 400, the relationship between the orientation of the simulated radial well 300 and the permeability of the simulated formation 400 was obtained by comparing the flow rates of specimens with different orientations of the simulated radial well 300, which is also the relationship between the orientation of the radial well and the permeability of the actual formation.

[0074] In summary, the simulation device of this invention can experimentally verify the impact of radial well setting parameters on injection and production effects under ground test conditions. It objectively illustrates the impact of radial well setting parameters on injection and production effects through experimental methods, laying the foundation for further research and development of radial drilling technology, providing reasonable guidance for the field application of radial drilling technology, and filling the gap in experimental research.

[0075] In some embodiments, the simulation cylinder 100 is provided with a plurality of seepage holes 120 for connecting the simulation space 110 with the external environment of the simulation cylinder 100, so that test fluid in the simulated formation 400 can seep out through the plurality of seepage holes 120.

[0076] During the test, the seepage hole 120 can promptly discharge the test fluid seeping from the simulated formation, making the fluid flow smoother and avoiding deviations in the verification results due to obstructed test fluid flow.

[0077] In some embodiments, when there are multiple simulated radial wells 300, the multiple simulated radial wells 300 are arranged at intervals along the length direction of the simulated wellbore 200. This arrangement is suitable for testing to verify the effect of radial well density on injection and production efficiency.

[0078] In some embodiments, when there are multiple simulated radial wells 300, the multiple simulated radial wells 300 are arranged at circumferential intervals along the simulated wellbore 200. This arrangement is suitable for testing the influence of the length and diameter of the radial well on the injection-production effect. Arranging multiple simulated radial wells 300 along the circumferential direction of the simulated wellbore 200 can increase the flow rate of the test fluid and improve the accuracy of the detected flow rate.

[0079] In some embodiments, when there are multiple simulated radial wells 300, the multiple simulated radial wells 300 are arranged at intervals along the length of the simulated wellbore 200 and circumferentially along the simulated wellbore 200. This arrangement is suitable for testing the influence of the length, diameter, and density of radial wells on the injection-production effect. This arrangement is also suitable for testing the influence of the density of radial wells on the injection-production effect. Arranging multiple simulated radial wells 300 circumferentially along the simulated wellbore 200 can increase the flow rate of the test fluid and improve the accuracy of the detected flow rate.

[0080] In some embodiments, the simulation device may further include a protective cylinder 500, which defines an upwardly open receiving space 510. The simulation cylinder 100 is disposed within the receiving space 510, and the protective cylinder 500 and its internal components are isolated from the outside world to protect the internal equipment.

[0081] Furthermore, the simulation cylinder 100 is provided with a plurality of seepage holes 120 for connecting the simulation space 110 and the containment space 510, so that the test fluid in the simulation stratum 400 can seep into the containment space 510 through the plurality of seepage holes 120.

[0082] Furthermore, a drain hole 520 is provided at the bottom of the protective cylinder 500. The drain hole 520 connects the accommodating space 510 with the external environment of the protective cylinder 500 to drain the test fluid in the accommodating space 510.

[0083] Specifically, the cross-section of the protective cylinder 500 is set to be larger than the cross-section of the simulated cylinder 100, and the drain hole 520 can be located on the bottom wall between the protective cylinder 500 and the simulated cylinder 100 to avoid the simulated cylinder 100 blocking the drain hole 520.

[0084] The space between the protective cylinder 500 and the simulated cylinder 100 can be used to collect the test fluid that seeps out from the seepage hole 120 of the simulated cylinder 100 during the test. After the test, the drain hole 520 can be opened to discharge the fluid, which is simple and convenient.

[0085] Furthermore, the simulation device may also include a cover 600, which is connected to the protective cylinder 500 and located at the opening of the receiving space 510 to close the receiving space 510 and the simulation space 110.

[0086] Specifically, in order to facilitate the placement of the solidified simulated wellbore 200 and simulated caliper 300 into the simulated cylinder 100, the simulated cylinder 100 can also be configured to open upwards.

[0087] Furthermore, the simulated cylinder 100 can also be configured such that when it is placed into the protective cylinder 500, the openings of both are at the same level, so that the cover 600 can simultaneously close the openings of both.

[0088] Furthermore, the cover 600 has a through hole 610. The simulated wellbore 200 has a casing 220 that passes through the through hole 610, such that a portion of it is outside the simulated wellbore 100. The first port of the casing 220 located outside the simulated wellbore 100 is used to introduce test fluid.

[0089] Specifically, the simulated wellbore 200 may further include a pressurization connector 230, which is disposed at the first port of the casing 220 for connecting to the test fluid. When connecting to the test fluid, the pressurization connector 230 can be connected to the pressurization device via a pressurization pipeline.

[0090] Furthermore, the simulated wellbore 200 may also include a plug plate 240, which is disposed at the second port of the casing 220 opposite to the first port, for sealing the casing 220.

[0091] The plug plate 240 can be connected to the end of the casing 220 by welding, and the area of ​​the plug plate 240 can be set to be larger than the cross-sectional area of ​​the casing 220. In this way, the plug plate 240 can increase the contact area with the simulated formation 400 and further improve the stability of the simulated wellbore 200.

[0092] See Figure 7 , Figure 7 This is a flowchart of a test method in one embodiment of the present invention. The present invention also provides a test method for a simulation device for a radial well system. This test method can employ the simulation device of any of the above embodiments, and the test method can be implemented through the following steps:

[0093] Step S710: Provide multiple simulation devices, wherein in the multiple simulation devices, one of the setting parameters of the simulated well 300 is configured as a variable parameter, and the remaining setting parameters are configured as quantitative parameters, wherein the setting parameters include the density of the simulated well 300, the length of the simulated well 300, the orientation of the simulated well 300, and the inner diameter of the simulated well 300.

[0094] Step S720: Introduce test fluid with the same preset pressure value into the pressurization channel 210 of the multiple simulation devices.

[0095] Step S730: Detect the flow rate of the test fluid in multiple simulation devices.

[0096] Step S740: Determine the relationship between the variable parameters and the simulated formation permeability 400 based on the flow rate of the test fluid.

[0097] In some embodiments, this experimental method can verify the influence of the diameter of the radial well on the injection-production effect, which can be achieved through the following steps:

[0098] See Figure 3 , Figure 3 This is a control principle for using a simulation device in one embodiment of the present invention. Figure 1 The test method can be carried out according to the following steps:

[0099] Multiple simulation devices are provided, with the diameter of the simulated well 300 set differently in each device, while other parameters (length, quantity, density, position, orientation, etc. of each component) remain the same. To improve the reliability of the test data, the number of simulation devices can be set to more than two, such as three or four. For example, as shown in Figures (3a), (3b), and (3c), the diameters of the simulated well 300 are set to d1, d2, and d3, which decrease sequentially.

[0100] Test fluid with the same preset pressure value is introduced into the pressurization channel 210 of multiple simulation devices.

[0101] The flow rate of the test fluid is detected in multiple simulation devices. In some specific embodiments, a flow detection unit 710 is provided on the pressurization pump 700 to detect the flow rate of the test fluid.

[0102] The relationship between the diameter of the simulated wellbore 300 and the formation permeability was determined based on the flow rate of the test fluid. Since the flow rate of the test fluid is positively correlated with the permeability of the simulated formation 400, the relationship between the diameter of the simulated wellbore 300 and the permeability of the simulated formation 400 was obtained by comparing the flow rates of specimens with different simulated wellbore 300 diameters, which is also the relationship between the diameter of the radial well and the permeability of the actual formation.

[0103] In some embodiments, this experimental method can verify the effect of radial well length on injection-production efficiency, which can be achieved through the following steps:

[0104] See Figure 4 , Figure 4 This is a control principle for using a simulation device in one embodiment of the present invention. Figure 2 The verification test can be conducted according to the following steps:

[0105] Multiple simulation devices are provided, with the length of the simulated wellbore 300 varying across these devices, while other parameters (diameter, number, density, position, orientation, etc. of each component) remain identical. To improve the reliability of the test data, the number of simulation devices can be greater than two, such as three or four groups. For example, as shown in Figures (4a), (4b), and (4c), the lengths of the simulated wellbore 300 are set to L1, L2, and L3, which decrease sequentially.

[0106] Test fluid with the same preset pressure value is introduced into the pressurization channel 210 of multiple simulation devices.

[0107] The flow rate of the test fluid is detected in multiple simulation devices.

[0108] The relationship between the length of the simulated radial well 300 and the formation permeability was determined based on the flow rate of the test fluid. Since the flow rate of the test fluid is positively correlated with the permeability of the simulated formation 400, the relationship between the length of the simulated radial well 300 and the permeability of the simulated formation 400 was obtained by comparing the flow rates of specimens with different lengths of simulated radial well 300, which is also the relationship between the length of the radial well and the permeability of the actual formation.

[0109] In some embodiments, this experimental method can verify the effect of radial well density on injection-production efficiency, which can be achieved through the following steps:

[0110] See Figure 5 , Figure 5 This is a control principle for using a simulation device in one embodiment of the present invention. Figure 3 The verification test can be conducted according to the following steps:

[0111] Multiple simulation devices are provided, with different densities of the simulated borehole 300 in each device, while keeping other parameters (diameter, quantity, position, orientation, etc. of each component) the same. To improve the reliability of the test data, the number of simulation devices can be greater than two, such as three or four. It should be noted that the density of the simulated borehole 300 can be understood as the tightness of the simulated borehole 300 along the axial direction of the simulated wellbore 200, and can be measured by setting the number of simulated boreholes 300 per unit length along the axial direction of the simulated wellbore 200. To improve the reliability of the test data, the number of simulation devices can be greater than two, such as three or four. For example, as shown in Figures (5a), (5b), and (5c), the density of the simulated borehole 300 is set to decrease sequentially.

[0112] Test fluid with the same preset pressure value is introduced into the pressurization channel 210 of multiple simulation devices.

[0113] The flow rate of the test fluid is detected in multiple simulation devices.

[0114] The relationship between the density of the simulated wellbore 300 and the permeability of the simulated formation 400 was determined based on the flow rate of the test fluid. Since the flow rate of the test fluid is positively correlated with the permeability of the simulated formation 400, the relationship between the density of the simulated wellbore 300 and the permeability of the simulated formation 400 was obtained by comparing the flow rates of density specimens of different simulated wellbore 300, which is also the relationship between the density of the radial well and the permeability of the actual formation.

[0115] In some embodiments, this experimental method can verify the influence of the radial well orientation on the injection-production effect, which can be achieved through the following steps:

[0116] See Figure 6 , Figure 6 This is a control principle for using a simulation device in one embodiment of the present invention. Figure 4 The verification test can be conducted according to the following steps:

[0117] Multiple simulation devices are provided, with the orientation of the simulated well 300 in each device set differently, while other parameters (diameter, number, density, position, etc. of each component) remain the same. To improve the reliability of the test data, the number of simulation devices can be set to more than two groups, such as three or four groups. For example, as shown in Figures (6a), (6b), and (6c), the orientation of the simulated well 300 is set to left, forward, and right respectively.

[0118] Test fluid with the same preset pressure value is introduced into the pressurization channel 210 of multiple simulation devices.

[0119] The flow rate of the test fluid is detected in multiple simulation devices.

[0120] The relationship between the orientation of the simulated radial well 300 and the permeability of the simulated formation 400 was determined based on the flow rate of the test fluid. Since the flow rate of the test fluid is positively correlated with the permeability of the simulated formation 400, the relationship between the orientation of the simulated radial well 300 and the permeability of the simulated formation 400 was obtained by comparing the flow rates of specimens with different orientations of the simulated radial well 300, which is also the relationship between the orientation of the radial well and the permeability of the actual formation.

[0121] In summary, the embodiments of this invention propose a test method for the radial well system, which can effectively verify the theoretical analysis of the influence of radial well setting parameters on injection and production effects under ground test conditions. It objectively illustrates the influence of drilling parameters on injection and production effects through test methods, lays the foundation for further research and development of radial drilling technology, provides reasonable guidance for the field application of radial drilling technology, and fills the gap in experimental research.

[0122] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A simulation device for a radial well system, characterized in that, include: A simulated cylinder (100) defines a simulated space (110) for accommodating a simulated stratum (400); A simulated wellbore (200), at least a portion of which is disposed within the simulated formation (400) within the simulated cylinder (100), and a pressurization channel (210) is further defined within the simulated wellbore (200); At least one simulated borehole (300) is connected to the simulated wellbore (200) and extends at an angle relative to the axial direction of the simulated wellbore (200). The simulated borehole (300) is located within the simulated formation (400) inside the simulated shell (100). A simulated channel (310) communicating with the pressurized channel (210) is defined within the simulated borehole (300). A plurality of jet holes (320) are provided on the simulated borehole (300) for communicating the simulated space (110) and the simulated channel (310). The simulation device is configured to introduce test fluid into the pressurized channel (210) so that the test fluid penetrates into the simulated formation (400) within the simulation space (110) through the simulation channel (310) and the plurality of jet holes (320).

2. The simulation device according to claim 1, characterized in that, The simulation cylinder (100) has multiple seepage holes (120) for connecting the simulation space (110) with the external environment of the simulation cylinder (100), so that the test fluid in the simulation stratum (400) can seep out through the multiple seepage holes (120).

3. The simulation device according to claim 1, characterized in that, When there are multiple simulated boreholes (300), the multiple simulated boreholes (300) are arranged at intervals along the length direction of the simulated wellbore (200); When there are multiple simulated boreholes (300), the multiple simulated boreholes (300) are arranged at circumferential intervals along the simulated wellbore (200); or, When there are multiple simulated boreholes (300), the multiple simulated boreholes (300) are arranged at intervals along the length direction of the simulated wellbore (200) and along the circumferential direction of the simulated wellbore (200).

4. The simulation device according to claim 1, characterized in that, Also includes: The protective cylinder (500) defines an upward-opening receiving space (510) inside; The simulated cylinder (100) is disposed within the containing space (510). The simulated cylinder (100) has a plurality of seepage holes (120) for connecting the simulated space (110) and the containing space (510) so that the test fluid in the simulated formation (400) can seep into the containing space (510) through the plurality of seepage holes (120).

5. The simulation device according to claim 4, characterized in that, The bottom of the protective cylinder (500) is provided with a drain hole (520), which connects the containment space (510) with the external environment of the protective cylinder (500) to drain the test fluid in the containment space (510).

6. The simulation device according to claim 4, characterized in that, Also includes: A cover (600) is connected to the protective cylinder (500) and located at the opening of the receiving space (510) to close the receiving space (510) and the simulated space (110).

7. The simulation device according to claim 6, characterized in that, The cover (600) has a through hole (610); The simulated wellbore (200) has a casing (220) that passes through the through hole (610) so that a portion of the casing (220) is outside the simulated wellbore (100). The first port of the casing (220) located outside the simulated wellbore (100) is used to introduce the test fluid.

8. The simulation device according to claim 7, characterized in that, The simulated wellbore (200) also includes: A pressure fitting (210) is disposed at the first port of the sleeve (220) for connecting the test fluid; A blocking plate (240) is disposed at the second port of the sleeve (220) opposite to the first port, for sealing the second port of the sleeve (220).

9. The simulation device according to claim 1, characterized in that, Also includes: A pressurizing pump (700) is provided, the outlet of which is connected to the simulated wellbore (200) to introduce test fluid into the pressurizing channel (210), and a flow detection unit (710) is provided on the pressurizing pump (700) to detect the flow rate of the test fluid.

10. A test method for a simulation device of a radial well system, characterized in that, The test method employs the simulation apparatus according to any one of claims 1 to 9, and the test method includes: A plurality of simulation devices are provided, wherein one of the settings parameters of the simulated well is configured as a variable parameter, and the remaining settings parameters are configured as quantitative parameters, wherein the settings parameters include the density of the simulated well, the length of the simulated well, the orientation of the simulated well, and the inner diameter of the simulated well; The test fluid with the same preset pressure value is introduced into the pressurization channel of the plurality of simulation devices; Detect the flow rate of the test fluid in multiple of the aforementioned simulation devices; The relationship between the variable parameters and the simulated formation permeability is derived based on the flow rate of the test fluid.

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