Horizontal well multi-cluster osculating fracturing process proppant migration simulation device and method

Abstract

The invention relates to a horizontal well multi-cluster osculating fracturing process propping agent migration simulation device and method. The simulation device comprises a simulation mechanism and an injection mechanism. The simulation mechanism comprises a simulation rock block, a plurality of aperture adjusting assemblies and a plurality of detection assemblies, the simulation rock block is made of a transparent material, an inflow hole extending in the horizontal direction is formed in the center of the simulation rock block, and a plurality of perforation clusters are formed in the side wall of the simulation rock block; and each perforation cluster comprises a plurality of perforations which are radially and uniformly distributed outwards by taking the inflow hole as the center on the section vertical to the inflow hole. According to the invention, the relation between the orientation of the perforation and the flow of the fracturing fluid is obtained by measuring the volume of the mixed liquid flowing out of the perforation in each orientation; by comparing the content of the propping agent in the mixed liquid flowing out of the perforations in different orientations, the relationship between the perforation orientation and the content of the propping agent is obtained, so that the influence of gravity on the concentration distribution of the propping agent of the fracturing fluid in different orientations is researched.

Description

Technical Field

[0001] This invention relates to the field of horizontal well multi-cluster dense cutting fracturing technology, and more specifically, to a device and method for simulating proppant migration in horizontal well multi-cluster dense cutting fracturing. Background Technology

[0002] To maximize the formation of complex fracture networks and achieve commercial development of shale gas under normal pressure, multi-cluster close-cut fracturing technology within horizontal well sections has been developed through field practice in recent years. Domestic and international experience in tight reservoir fracturing shows that the smaller the spacing between fracturing clusters in horizontal wells, the more effectively the reservoir can be "crushed," resulting in denser fractures, more thorough reservoir stimulation, and improved permeability of the fracture system surrounding the wellbore. Fracturing technology has gradually shifted from simply pursuing fracturing sweep volume to maximizing the density of volumetric fractures within a limited sweep area, and from a well-controlled reserve model to a fracture-controlled reserve model, fully releasing shale gas production capacity, thus gradually forming the concept of close-cut fracturing technology. In terms of segmented cluster parameter design, the focus has shifted from conventional segmented clustering to multi-cluster close-cut design, significantly improving the volumetric fracturing stimulation effect.

[0003] Since research on multi-cluster close-cut fracturing technology is still in its early stages, the following technical problems remain:

[0004] (1) It is unclear whether there is a difference in flow rate in perforations of different orientations. For horizontal wells, each perforation cluster usually includes 6 to 8 perforations of different orientations. In fracturing design, it is usually assumed that the flow rate of fracturing fluid injected from perforations of different orientations is equal. However, due to the influence of gravity, the gravitational potential energy of fracturing fluid injected from upward perforations will increase, while the gravitational potential energy of fracturing fluid injected from downward perforations will decrease. Therefore, theoretically, there will be a certain difference in the flow rate of fracturing fluid injected from perforations of different orientations. Therefore, it is necessary to study the influence of gravity on the flow rate distribution of fracturing fluid in different orientations.

[0005] (2) It is unclear whether there is a difference in proppant concentration in perforations at different orientations. For horizontal wells, it is generally assumed that the proppant concentration of fracturing fluid from perforations at different orientations is equal during fracturing design. However, due to the influence of gravity, when the fracturing fluid flows horizontally, the proppant may undergo gravity stratification. Therefore, theoretically, there will be a certain difference in the proppant concentration of fracturing fluid from perforations at different orientations. Therefore, it is necessary to study the influence of gravity on the proppant concentration of fracturing fluid at different orientations.

[0006] (3) When designing fracturing, it is necessary to select a suitable perforation diameter. In the existing technology, the selection of perforation diameter mainly relies on experience, and there is a lack of research on the fracturing fluid passage effect of different perforation diameters.

[0007] (4) When designing fracturing, it is necessary to select the appropriate proppant type and particle size. In the existing technology, the selection of proppant type and particle size mainly relies on experience, and there is a lack of research on the fracturing fluid passage effect of different proppant types and particle sizes. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a device and method for simulating proppant migration in horizontal well multi-cluster dense cutting fracturing process, so as to study the influence of gravity on the flow distribution of fracturing fluid and the proppant concentration distribution in different orientations, as well as the influence of perforation diameter, proppant type and particle size on the fracturing fluid passage effect.

[0009] The technical solution adopted by the present invention to solve its technical problem is: to construct a horizontal well multi-cluster dense cutting fracturing process proppant migration simulation device, including a simulation mechanism and an injection mechanism;

[0010] The simulation mechanism includes a simulated rock block, several aperture adjustment components, and several detection components. The simulated rock block is made of transparent material. A flow inlet hole extending horizontally is opened in the center of the simulated rock block. Several perforation clusters are opened on the side wall of the simulated rock block. Each perforation cluster includes several perforations that are evenly distributed radially outward from the flow inlet hole on a cross section perpendicular to the flow inlet hole. The detection components include several light sources and several receivers. A first placement slot and a second placement slot are opened on both sides of each perforation hole on the simulated rock block. Each light source is correspondingly set in each of the first placement slots, and each receiver is correspondingly set in each of the second placement slots.

[0011] The injection mechanism is connected to the inlet hole and is used to inject proppant into the simulated rock block.

[0012] According to the above scheme, the aperture adjustment assembly includes a sliding plate, a first rubber sheet, a second rubber sheet, a sealing rubber sheet, and an adjustment drive component. The sliding plate is slidably disposed in the corresponding perforation hole. One end of the first rubber sheet and the second rubber sheet are both fixed to the first inner sidewall of the corresponding perforation hole. The sealing rubber sheet is used to block the channel formed by the first rubber sheet, the second rubber sheet, the sliding plate, and the first inner sidewall. The adjustment drive component is connected to the sliding plate and is used to drive the sliding plate to move.

[0013] According to the above scheme, the adjustment drive component includes a fixed block, a first guide rod, and an adjustment screw. The fixed block is fixed to the outer wall of the simulated rock block. The fixed block has a first guide hole and a screw hole. The first guide rod is slidably inserted into the first guide hole. The first guide rod is fixedly connected to the corresponding sliding plate. The adjustment screw is threaded into the screw hole. One end of the adjustment screw is rotatably connected to the sliding plate.

[0014] According to the above scheme, the simulated rock block is also provided with a number of second guide holes that correspond one-to-one with each of the perforations. Each second guide hole is perpendicular to and connected to the corresponding perforation. A second guide rod is also fixed on the sliding plate, and the second guide rod is slidably inserted into the corresponding second guide hole.

[0015] According to the above scheme, the adjustment drive component also includes a bearing, the inner ring of which is fixedly sleeved on the adjustment screw, and the outer ring of which is fixedly connected to the sliding plate.

[0016] According to the above scheme, the sealing rubber sheet has an adhesive surface, which is used to fix it to the inner wall of the inlet hole. One end of the first rubber sheet and one end of the second rubber sheet are both fixedly attached to the adhesive surface.

[0017] According to the above scheme, the injection mechanism includes several mixing tanks and a delivery pump. Each mixing tank contains a proppant, the delivery pump is connected to the outlet of the mixing tank, and the outlet of the delivery pump is connected to the inlet hole.

[0018] According to the above scheme, the injection mechanism further includes several inlet branch pipes, an inlet main pipe, and an outlet pipe. One end of the inlet branch pipe is connected to the outlet of the corresponding mixing tank, and the other end of the inlet branch pipe is connected to the inlet main pipe. A first regulating valve is provided on the inlet branch pipe. The inlet main pipe is connected to the inlet of the delivery pump. One end of the outlet pipe is connected to the outlet of the delivery pump, and the other end of the outlet pipe is connected to the inlet hole. A second regulating valve and a flow meter are provided on the outlet pipe.

[0019] According to the above scheme, the simulation mechanism also includes several liquid receiving funnels, liquid receiving hoses and measuring cylinders. The inlet of the liquid receiving funnel is attached to the outside of the corresponding perforation hole. One end of the liquid receiving hose is connected to the liquid outlet of the liquid receiving funnel, and the other end of the liquid receiving hose is connected to the measuring cylinder.

[0020] This invention also provides a method for simulating proppant migration in horizontal well multi-cluster close-cut fracturing processes, using the aforementioned horizontal well multi-cluster close-cut fracturing proppant migration simulation device, characterized by comprising the following steps:

[0021] S1. Different types or different mesh sizes of proppant are loaded into each mixing tank and mixed with fracturing fluid. The mixture in one mixing tank is fed into the inlet hole of the simulated rock block by a delivery pump. The mixture enters each perforation and is discharged outside the simulated rock block.

[0022] S2. Prepare a container for each perforation to collect the mixture flowing out of the perforation, so as to obtain the volume of the mixture flowing out of each perforation within a preset time. By comparing the volume of the mixture flowing out of perforations in different directions, the relationship between the perforation direction and the fracturing fluid flow rate can be obtained.

[0023] S3. A light beam is emitted from the light source to the corresponding perforation, and the light beam is received by the receiver. When the mixture flows through each perforation, the proppant in the mixture will block the light. The content of proppant in the mixture can be determined by the shadow area in the image received by the receiver. By comparing the proppant content in the mixture flowing out of the perforation at different locations, the relationship between the perforation location and the proppant content can be obtained.

[0024] S4. Connect the inlet of the delivery pump to other mixing tanks to change the type or mesh size of the proppant. Repeat steps S1-S3 to obtain the volume of the mixture flowing out of each perforation and the proppant content within a preset time. Then obtain the distribution of proppant content with perforation orientation. Compare the distribution of proppant content with perforation orientation under different proppant types or mesh sizes to determine the influence of proppant type on the distribution of proppant content with perforation orientation.

[0025] S5. By synchronously driving each sliding plate through each adjustment drive component, the effective orifice diameter of each perforation is changed. Repeat steps S1-S3 to obtain the volume of the mixture flowing out of each perforation and the proppant content within a preset time. By comparing the volume of the mixture flowing out of perforations in the same orientation and the proppant content, the relationship between the perforation flow rate and the proppant content and the effective orifice diameter is obtained.

[0026] The proppant migration simulation device and method for horizontal well multi-cluster close-cut fracturing process of the present invention have the following beneficial effects:

[0027] 1. This invention involves opening a horizontally extending inlet hole at the center of a simulated rock block, and then uniformly distributing several perforations radially outward from the inlet hole on a cross-section perpendicular to the inlet hole. By measuring the volume of the mixed fluid flowing out of the perforations at each orientation, the relationship between the orientation of the perforations and the fracturing fluid flow rate can be obtained. This allows for the study of the influence of gravity on the flow rate distribution of fracturing fluid at different orientations.

[0028] 2. This invention emits a light beam to the corresponding perforation through a light source and receives the light beam through a receiver. When the mixture flows through each perforation, the proppant in the mixture will block the light. Therefore, the content of proppant in the mixture can be determined by the shadow area in the image received by the receiver. By comparing the proppant content in the mixture flowing out of perforations at different orientations, the relationship between the perforation orientation and the proppant content can be obtained. Thus, the influence of gravity on the proppant concentration distribution of fracturing fluid at different orientations can be studied.

[0029] 3. The present invention slides a sliding plate in each perforation and fixes a retractable first rubber sheet, a second rubber sheet, and a sealing rubber sheet between the first inner wall of the perforation and the sliding plate. By adjusting the driving component to move the sliding plate, the effective diameter of the perforation can be changed. By comparing the volume of the mixed liquid flowing out of the perforation at the same position under different effective diameters and the proppant content, the relationship between the perforation flow rate and proppant content and the effective diameter of the perforation can be obtained.

[0030] 4. This invention sets up multiple mixing tanks, each containing different types or mesh sizes of proppant, which are then mixed with fracturing fluid. During the experiment, the inlet of the delivery pump is connected to different mixing tanks to change the type or mesh size of the proppant. The distribution of proppant content with perforation orientation under different proppant types or mesh sizes is compared to determine the effect of proppant type or mesh size on the distribution of proppant content with perforation orientation. Attached Figure Description

[0031] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0032] Figure 1 This is a schematic diagram of an embodiment of the proppant migration simulation device and method for horizontal well multi-cluster dense cutting fracturing process provided by the present invention;

[0033] Figure 2 yes Figure 1 A schematic diagram of the injection mechanism in the diagram;

[0034] Figure 3 yes Figure 1 A schematic diagram of the simulation mechanism in the diagram;

[0035] Figure 4 yes Figure 3 A magnified view of a portion of region A in the middle;

[0036] Figure 5 yes Figure 4 A schematic diagram of the structure after the sliding plate moves to the right;

[0037] Figure 6 yes Figure 3 A three-dimensional structural diagram of the simulation mechanism (with the liquid receiving funnel omitted);

[0038] Figure 7 yes Figure 6 A magnified view of a portion of region B in the middle;

[0039] Figure 8 yes Figure 6 Exploded view;

[0040] Figure 9 yes Figure 8 A three-dimensional structural diagram of an aperture adjustment component;

[0041] Figure 10 yes Figure 9 A three-dimensional structural diagram of the aperture adjustment component from another perspective;

[0042] Figure 11 yes Figure 9 A magnified view of a portion of region C in the middle;

[0043] In the diagram: 1-Simulation mechanism, 11-Simulation rock block, 111-Inlet hole, 112-Perforation hole, 113-First placement groove, 114-Second placement groove, 115-Second guide hole, 12-Aperture adjustment component, 121-Sliding plate, 122-First rubber sheet, 123-Second rubber sheet, 124-Sealing rubber sheet, 1241-Contact surface, 125-Adjustment drive component, 1251-Fixing block, 1252-First guide rod, 125 3-Adjusting screw, 1254-Bearing, 126-Second guide rod, 13-Detection component, 131-Light source, 132-Receiver, 14-Liquid receiving funnel, 141-Liquid outlet, 142-First funnel section, 143-Second funnel section, 2-Injection mechanism, 21-Stirring tank, 22-Transfer pump, 23-Inlet branch pipe, 24-Inlet main pipe, 25-Outlet pipe, 26-First regulating valve, 27-Second regulating valve, 28-Flow meter. Detailed Implementation

[0044] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0045] Please refer to Figures 1-11 The present invention provides a simulation device for proppant migration in horizontal well multi-cluster dense cutting fracturing process, including a simulation mechanism 1 and an injection mechanism 2;

[0046] The simulation mechanism 1 includes a simulated rock block 11, several aperture adjustment components 12, and several detection components 13. The simulated rock block 11 is made of transparent material. A horizontally extending inlet hole 111 is formed at the center of the simulated rock block 11. Several perforation clusters are formed on the sidewalls of the simulated rock block 11. Each perforation cluster includes several perforations 112 evenly distributed radially outward from the inlet hole 111 on a cross-section perpendicular to the inlet hole 111. A first placement groove 113 and a second placement groove 114 are formed on both sides of each perforation 112 on the simulated rock block 11. The number of aperture adjustment components 12 is the same as the number of perforations 112 and corresponds one-to-one. Each aperture adjustment component 12 includes a sliding plate 121, a first rubber sheet 122, and a second rubber sheet 123. The assembly includes a sealing rubber sheet 124 and an adjusting drive component 125. The sliding plate 121 is slidably disposed in the corresponding injection hole 112. One end of the first rubber sheet 122 and the second rubber sheet 123 are fixed to the first inner sidewall of the corresponding injection hole 112. The sealing rubber sheet 124 is used to block the channel formed by the first rubber sheet 122, the second rubber sheet 123, the sliding plate 121 and the first inner sidewall. The adjusting drive component 125 is connected to the sliding plate 121 and is used to drive the sliding plate 121 to move. The detection assembly 13 includes a plurality of light sources 131 and a plurality of receivers 132. Each light source 131 is disposed in each of the first placement slots 113, and each receiver 132 is disposed in each of the second placement slots 114.

[0047] The injection mechanism 2 includes several mixing tanks 21 and a delivery pump 22. Each mixing tank 21 is used to load different types or different mesh sizes of proppant. The inlet of the delivery pump 22 can be selectively connected to the outlet of each mixing tank 21, and the outlet of the delivery pump 22 is connected to the inlet hole 111.

[0048] In operation, different types or mesh sizes of proppant are loaded into each mixing tank 21 and mixed with fracturing fluid. The mixture from one mixing tank 21 is then pumped into the inlet 111 of the simulated rock block 11 via a delivery pump 22. The mixture then enters each perforation 112 and is discharged outside the simulated rock block 11. A container is prepared for each perforation 112 to collect the volume of the mixture flowing out of that perforation 112, thus obtaining the volume of the mixture flowing out of each perforation 112 within a preset time. By comparing the volume of the mixture flowing out of perforations 112 at different locations, the relationship between the perforation location and the fracturing fluid flow rate is determined. Simultaneously, a light beam is emitted from a light source 131 to the corresponding perforation 112, and the light beam is received by a receiver 132. When the mixture flows through each perforation 112, the proppant in the mixture blocks the light, allowing the proppant content in the mixture to be determined by the shadow area in the image received by the receiver 132. By comparing the volume of the mixture flowing out of perforations 112 at different locations... The proppant content in the outflowing mixture is used to determine the relationship between the perforation orientation and the proppant content. Next, the inlet of the transfer pump 22 is connected to another mixing tank 21 to change the type or mesh size of the proppant. This process is repeated to obtain the volume of the mixture flowing out of each perforation 112 and the proppant content within a preset time. This yields the distribution of the proppant content with the perforation orientation. By comparing the distribution of the proppant content with the perforation orientation under different proppant types or mesh sizes, the influence of the proppant type on the distribution of the proppant content with the perforation orientation is determined. Then, each adjusting drive 125 synchronously moves each sliding plate 121 to change the effective aperture of each perforation 112. This process is repeated to obtain the volume of the mixture flowing out of each perforation 112 within a preset time and the proppant content. By comparing the volume of the mixture flowing out of perforations 112 with the same orientation and the proppant content, the relationship between the perforation flow rate, the proppant content, and the effective aperture size of the perforation is determined.

[0049] It should be noted that the sliding plate 121 is made of a transparent material, allowing light to pass through, so that the receiver 132 can receive the light beam emitted by the light source 131.

[0050] To understand how to adjust the function of drive component 125, please refer to [the relevant documentation / reference]. Figures 3-11In a preferred embodiment, the adjusting drive component 125 includes a fixing block 1251, a first guide rod 1252, and an adjusting screw 1253. The fixing block 1251 is fixed to the outer wall of the simulated rock block 11. The fixing block 1251 has a first guide hole and a screw hole. The first guide rod 1252 is slidably inserted into the first guide hole and is fixedly connected to the corresponding sliding plate 121. The adjusting screw 1253 is threaded into the screw hole, and one end of the adjusting screw 1253 is rotatably connected to the sliding plate 121. In use, when the adjusting screw 1253 is rotated, the adjusting screw 1253 will move along its length, thereby driving the sliding plate 121 to move. The function of the first guide rod 1252 is to guide the movement of the sliding plate 121. Figure 4 and Figure 5 When the sliding plate 121 moves to the right, the distance between the right side wall of the sliding plate 121 and the inner wall opposite to the perforation 112 decreases. Due to the presence of the first rubber sheet 122, the second rubber sheet 123, and the sealing rubber sheet 124, the liquid can only flow out from between the right side wall of the sliding plate 121 and the inner wall opposite to the perforation 112, and cannot flow out from the left side of the sliding plate 121. Therefore, the effective diameter of the perforation 112 can be reduced. Conversely, if the sliding plate 121 is moved to the left, the effective diameter of the perforation 112 can be increased.

[0051] To specifically achieve the rotatable connection between one end of the adjusting screw 1253 and the sliding plate 121, please refer to... Figure 4 and Figure 5 In a preferred embodiment, the adjusting drive 125 further includes a bearing 1254, the inner ring of which is fixedly sleeved on the adjusting screw 1253, and the outer ring of which is fixedly connected to the sliding plate 121.

[0052] To improve the stability of the sliding plate 121 during movement, please refer to... Figures 3-5 In a preferred embodiment, the simulated rock block 11 is further provided with a plurality of second guide holes 115 corresponding one-to-one with each of the perforations 112. Each of the second guide holes 115 is perpendicular to and connected to the corresponding perforation 112. A second guide rod 126 is also fixed on the sliding plate 121. The second guide rod 126 is slidably inserted into the corresponding second guide hole 115. When the sliding plate 121 moves, the second guide rod 126 moves in the second guide hole 115, thereby improving the stability of the sliding plate 121 during the movement process.

[0053] To understand the specific function of the sealing rubber sheet 124, please refer to... Figures 3-10In a preferred embodiment, the sealing rubber sheet 124 has a bonding surface 1241, which is used to fix it to the inner wall of the inlet hole 111. One end of the first rubber sheet 122 and one end of the second rubber sheet 123 are both fixedly bonded to the bonding surface 1241. The sealing rubber sheet 124, the first rubber sheet 122, and the second rubber sheet 123 are all made of soft elastic rubber. When the sliding plate 121 moves to the right, the sealing rubber sheet 124, the first rubber sheet 122, and the second rubber sheet 123 are all fixedly bonded to the inner wall of the inlet hole 111. The second rubber sheet 123 is stretched. When the sliding plate 121 moves to the left, the sealing rubber sheet 124, the first rubber sheet 122 and the second rubber sheet 123 all contract. The sealing rubber sheet 124, the first rubber sheet 122 and the second rubber sheet 123, the sliding plate 121 and the first inner wall of the perforation 112 form a space. The fluid in the inlet hole 111 cannot enter this space. As the sliding plate 121 moves, the volume of this space increases or decreases accordingly, thereby decreasing or increasing the effective aperture of the perforation 112.

[0054] To facilitate the collection of the mixture flowing out of each perforation 112, please refer to... Figure 3 and Figure 4 In a preferred embodiment, the simulation mechanism 1 further includes a plurality of liquid receiving funnels 14, liquid receiving hoses, and measuring cylinders (not shown). The inlet of the liquid receiving funnel 14 is attached to the outside of the corresponding injection hole 112. One end of the liquid receiving hose is connected to the liquid outlet 141 of the liquid receiving funnel 14, and the other end of the liquid receiving hose is connected to the measuring cylinder. In use, after the liquid flows out of the injection hole 112, it will flow into the liquid receiving funnel 14 and then enter the corresponding measuring cylinder through the liquid receiving hose.

[0055] To prevent liquid from pooling in receiving funnel 14 and failing to flow completely into the corresponding measuring cylinder, please refer to... Figure 3 and Figure 4 In a preferred embodiment, the liquid outlet 141 of the receiving funnel 14 is located at the lower end of the receiving funnel 14. Specifically, this embodiment includes two types of receiving funnels 14. When the receiving funnel 14 is attached to the bottom surface of the simulated rock block 11, the first type of receiving funnel 14 is used. The first type of receiving funnel 14 is a common funnel with its opening and inlet facing each other. When the receiving funnel 14 is attached to the top surface of the simulated rock block 11, the second type of receiving funnel 14 is used. The second type of receiving funnel 14 is a specially made funnel with its opening and inlet on the same side. When the receiving funnel 14 is attached to the vertical side of the simulated rock block 11, both types of receiving funnels 14 can be used. This arrangement ensures that the liquid outlet 141 of the receiving funnel 14 is located at the lower end of the receiving funnel 14, thereby preventing liquid from accumulating in the receiving funnel 14 and not flowing entirely into the corresponding measuring cylinder, which would affect the accuracy of the measurement results.

[0056] To prevent the receiving funnel 14 from affecting the use of the adjusting drive 125, please refer to... Figure 3 and Figure 4 In a preferred embodiment, the liquid receiving funnel 14 includes a first funnel portion 142 and a second funnel portion 143. The first funnel portion 142 is fixed to the simulated rock block 11, and the second funnel portion 143 is threadedly connected to the first funnel portion 142. When it is necessary to adjust the adjusting drive component 125, the second funnel portion 143 is unscrewed, and after the adjustment is completed, the second funnel portion 143 is screwed back on.

[0057] To control injection mechanism 2, please refer to... Figure 1 and Figure 2 In a preferred embodiment, the injection mechanism 2 further includes a plurality of inlet branch pipes 23, an inlet main pipe 24, and an outlet pipe 25. One end of the inlet branch pipe 23 is connected to the outlet of the corresponding mixing tank 21, and the other end of the inlet branch pipe 23 is connected to the inlet main pipe 24. A first regulating valve 26 is provided on the inlet branch pipe 23. The inlet main pipe 24 is connected to the inlet of the delivery pump 22. One end of the outlet pipe 25 is connected to the outlet of the delivery pump 22, and the other end of the outlet pipe 25 is connected to the inlet hole 111. A second regulating valve 27 and a flow meter 28 are provided on the outlet pipe 25.

[0058] This invention also provides a method for simulating proppant migration in horizontal well multi-cluster close-cut fracturing processes, applicable to the aforementioned horizontal well multi-cluster close-cut fracturing proppant migration simulation device, and comprising the following steps:

[0059] S1. Different types or different mesh sizes of proppant are loaded into each mixing tank 21 and mixed with fracturing fluid. The mixture in one mixing tank 21 is input into the inlet hole 111 of the simulated rock block 11 by the delivery pump 22. The mixture enters each perforation 112 and is discharged to the outside of the simulated rock block 11.

[0060] S2. Prepare a container for each perforation 112 to collect the mixed liquid flowing out of the perforation 112, so as to obtain the volume of the mixed liquid flowing out of each perforation 112 within a preset time. By comparing the volume of the mixed liquid flowing out of the perforation 112 in different directions, the relationship between the perforation direction and the fracturing fluid flow rate can be obtained.

[0061] S3. A light beam is emitted from the light source 131 to the corresponding perforation 112, and the light beam is received by the receiver 132. When the mixture flows through each perforation 112, the proppant in the mixture will block the light. The content of proppant in the mixture can be determined by the shadow area in the image received by the receiver 132. By comparing the proppant content in the mixture flowing out of the perforation 112 at different locations, the relationship between the perforation location and the proppant content can be obtained.

[0062] S4. Connect the inlet of the delivery pump 22 to another mixing tank 21 to change the type or mesh size of the proppant. Repeat steps S1-S3 to obtain the volume of the mixture flowing out of each perforation 112 and the proppant content within a preset time. Then obtain the distribution of proppant content with perforation orientation. Compare the distribution of proppant content with perforation orientation under different proppant types or mesh sizes to obtain the influence of proppant type on the distribution of proppant content with perforation orientation.

[0063] S5. By synchronously driving each sliding plate 121 to move through each adjusting drive component 125, the effective aperture of each perforation 112 is changed. Repeat steps S1-S3 to obtain the volume of the mixture flowing out of each perforation 112 and the proppant content within a preset time. By comparing the volume of the mixture flowing out of the perforation 112 in the same position and the proppant content, the relationship between the perforation flow rate and the proppant content and the effective aperture of the perforation is obtained.

[0064] In summary, the beneficial effects of the technical solution provided by this invention include:

[0065] (1) By opening an inlet hole 111 extending horizontally in the center of the simulated rock block 11, and by uniformly distributing several perforations 112 radially outward from the inlet hole 111 on the cross section perpendicular to the inlet hole 111, the volume of the mixed fluid flowing out of the perforations 112 in each orientation is measured, and the relationship between the orientation of the perforation and the fracturing fluid flow rate is obtained. Thus, the influence of gravity on the flow rate distribution of fracturing fluid in different orientations can be studied.

[0066] (2) A light beam is emitted from the light source 131 to the corresponding perforation 112 and received by the receiver 132. When the mixture flows through each perforation 112, the proppant in the mixture will block the light. The content of proppant in the mixture can be determined by the shadow area in the image received by the receiver 132. By comparing the proppant content in the mixture flowing out of the perforation 112 in different orientations, the relationship between the perforation orientation and the proppant content can be obtained. Thus, the influence of gravity on the proppant concentration distribution of fracturing fluid in different orientations can be studied.

[0067] (3) By sliding a sliding plate 121 in each perforation 112, and by fixing a retractable first rubber sheet 122, second rubber sheet 123 and sealing rubber sheet 124 between the first inner sidewall of the perforation 112 and the sliding plate 121, the effective aperture of the perforation 112 can be changed by adjusting the driving component 125 to drive the sliding plate 121 to move. By comparing the volume of the mixed liquid flowing out of the perforation 112 in the same position under different effective apertures and the proppant content, the relationship between the perforation flow rate and proppant content and the effective aperture size of the perforation can be obtained.

[0068] (4) By setting up multiple mixing tanks 21, different types or different mesh sizes of proppant are loaded into each mixing tank 21 and mixed with fracturing fluid. During the experiment, the inlet of the delivery pump 22 is connected to different mixing tanks 21 to change the type or mesh size of the proppant. The distribution of proppant content with perforation orientation under different proppant types or mesh sizes is compared to obtain the effect of proppant type or mesh size on the distribution of proppant content with perforation orientation.

[0069] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A device for simulating proppant migration in horizontal well multi-cluster close-cut fracturing process, characterized in that, Includes simulation mechanism and injection mechanism; The simulation mechanism includes a simulated rock block, several aperture adjustment components, and several detection components. The simulated rock block is made of transparent material. A flow inlet hole extending horizontally is opened in the center of the simulated rock block. Several perforation clusters are opened on the side wall of the simulated rock block. Each perforation cluster includes several perforations that are evenly distributed radially outward from the flow inlet hole on a cross section perpendicular to the flow inlet hole. The detection components include several light sources and several receivers. A first placement slot and a second placement slot are opened on both sides of each perforation hole on the simulated rock block. Each light source is correspondingly set in each of the first placement slots, and each receiver is correspondingly set in each of the second placement slots. The injection mechanism is connected to the inlet hole and is used to inject proppant into the simulated rock block.

2. The proppant migration simulation device for horizontal well multi-cluster close-cut fracturing process according to claim 1, characterized in that, The aperture adjustment assembly includes a sliding plate, a first rubber sheet, a second rubber sheet, a sealing rubber sheet, and an adjustment drive. The sliding plate is slidably disposed within the corresponding perforation hole. One end of the first rubber sheet and the second rubber sheet are both fixed to the first inner sidewall of the corresponding perforation hole. The sealing rubber sheet is used to block the channel formed by the first rubber sheet, the second rubber sheet, the sliding plate, and the first inner sidewall. The adjustment drive is connected to the sliding plate and is used to drive the sliding plate to move.

3. The proppant migration simulation device for horizontal well multi-cluster close-cut fracturing process according to claim 2, characterized in that, The adjustment drive component includes a fixed block, a first guide rod, and an adjustment screw. The fixed block is fixed to the outer wall of the simulated rock block. The fixed block has a first guide hole and a screw hole. The first guide rod is slidably inserted into the first guide hole and is fixedly connected to the corresponding sliding plate. The adjustment screw is threaded into the screw hole, and one end of the adjustment screw is rotatably connected to the sliding plate.

4. The proppant migration simulation device for horizontal well multi-cluster close-cut fracturing process according to claim 3, characterized in that, The simulated rock block is also provided with a number of second guide holes that correspond one-to-one with each of the perforations. Each of the second guide holes is perpendicular to and connected to the corresponding perforation. A second guide rod is also fixed on the sliding plate and is slidably inserted into the corresponding second guide hole.

5. The proppant migration simulation device for horizontal well multi-cluster close-cut fracturing process according to claim 1, characterized in that, The adjustment drive component also includes a bearing, the inner ring of which is fixedly sleeved on the adjustment screw, and the outer ring of which is fixedly connected to the sliding plate.

6. The proppant migration simulation device for horizontal well multi-cluster close-cut fracturing process according to claim 2, characterized in that, The sealing rubber sheet has an adhesive surface, which is used to fix it to the inner wall of the inlet hole. One end of the first rubber sheet and one end of the second rubber sheet are both fixedly attached to the adhesive surface.

7. The proppant migration simulation device for horizontal well multi-cluster close-cut fracturing process according to claim 1, characterized in that, The injection mechanism includes several mixing tanks and a delivery pump. Each mixing tank contains a proppant. The delivery pump is connected to the outlet of the mixing tank, and the outlet of the delivery pump is connected to the inlet hole.

8. The proppant migration simulation device for horizontal well multi-cluster close-cut fracturing process according to claim 7, characterized in that, The injection mechanism further includes several inlet branch pipes, an inlet main pipe, and an outlet pipe. One end of each inlet branch pipe is connected to the outlet of the corresponding mixing tank, and the other end of each inlet branch pipe is connected to the inlet main pipe. A first regulating valve is provided on the inlet branch pipe. The inlet main pipe is connected to the inlet of the delivery pump. One end of each outlet pipe is connected to the outlet of the delivery pump, and the other end of each outlet pipe is connected to the inlet orifice. A second regulating valve and a flow meter are provided on the outlet pipe.

9. The proppant migration simulation device for horizontal well multi-cluster close-cut fracturing process according to claim 1, characterized in that, The simulation mechanism also includes several liquid receiving funnels, liquid receiving hoses, and measuring cylinders. The inlet of each liquid receiving funnel is attached to the outside of the corresponding perforation hole. One end of each liquid receiving hose is connected to the liquid outlet of the liquid receiving funnel, and the other end of each liquid receiving hose is connected to the measuring cylinder.

10. A method for simulating proppant migration in a horizontal well multi-cluster close-cut fracturing process, comprising the proppant migration simulation device for a horizontal well multi-cluster close-cut fracturing process as described in any one of claims 1-9, characterized in that, Includes the following steps: S1. Different types or different mesh sizes of proppant are loaded into each mixing tank and mixed with fracturing fluid. The mixture in one mixing tank is fed into the inlet hole of the simulated rock block by a delivery pump. The mixture enters each perforation and is discharged outside the simulated rock block. S2. Prepare a container for each perforation to collect the mixture flowing out of the perforation, so as to obtain the volume of the mixture flowing out of each perforation within a preset time. By comparing the volume of the mixture flowing out of perforations in different directions, the relationship between the perforation direction and the fracturing fluid flow rate can be obtained. S3. A light beam is emitted from the light source to the corresponding perforation, and the light beam is received by the receiver. When the mixture flows through each perforation, the proppant in the mixture will block the light. The content of proppant in the mixture can be determined by the shadow area in the image received by the receiver. By comparing the proppant content in the mixture flowing out of the perforation at different locations, the relationship between the perforation location and the proppant content can be obtained. S4. Connect the inlet of the delivery pump to other mixing tanks to change the type or mesh size of the proppant. Repeat steps S1-S3 to obtain the volume of the mixture flowing out of each perforation and the proppant content within a preset time. Then obtain the distribution of proppant content with perforation orientation. Compare the distribution of proppant content with perforation orientation under different proppant types or mesh sizes to determine the influence of proppant type on the distribution of proppant content with perforation orientation. S5. By synchronously driving each sliding plate through each adjustment drive component, the effective orifice diameter of each perforation is changed. Repeat steps S1-S3 to obtain the volume of the mixture flowing out of each perforation and the proppant content within a preset time. By comparing the volume of the mixture flowing out of perforations in the same orientation and the proppant content, the relationship between the perforation flow rate and the proppant content and the effective orifice diameter is obtained.

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