CN110952971A - Flat plate and experimental device for simulating influence of even fluid loss of reservoir on proppant paving - Google Patents

Abstract

The invention discloses a visual flat plate for simulating the influence of uniform filtration loss of fracturing fluid in a homogeneous reservoir on proppant conveying and migration in a hydraulic fracturing process and an experimental device thereof, wherein the experimental device comprises a flat plate for simulating the uniform filtration loss of the fracturing fluid in the homogeneous reservoir, a filter screen is arranged on the inner surface of the visual flat plate where a drain hole is positioned, the left end of the flat plate is sequentially connected with an inlet shaft, a conveying pump and a sand mixing tank, a flow meter and a pressure gauge are arranged between the inlet shaft and the conveying pump, and a valve is arranged between the conveying pump and the sand mixing tank; the right end of the flat plate is connected with a waste liquid collecting system, the waste liquid collecting system comprises an outlet shaft and a waste liquid collecting tank which are connected, and a pressure gauge is arranged between the outlet shaft and the waste liquid collecting tank; the drain hole is connected to a fluid loss system. The method can effectively and really simulate the migration condition of the proppant under the leachable reservoir, and has great significance for guiding hydraulic fracturing construction.

Description

Flat plate and experimental device for simulating influence of even fluid loss of reservoir on proppant paving

Technical Field

The invention relates to the technical field of oil and gas field development, in particular to a flat plate and an experimental device for simulating the influence of uniform reservoir filtration on proppant paving.

Background

In the hydraulic fracturing, a high-pressure pump set is utilized to inject a fracturing liquid pump into a stratum, and an oil-gas reservoir is pressed open when the fracture pressure of the stratum is exceeded, so that the oil-gas productivity is released, the yield increasing effect is achieved, and the oil-gas recovery rate is improved. After the reservoir is pressed open, proppant particles are injected to keep the pressed open fracture to be still capable of keeping a certain opening degree when the ground pump is stopped and the fracture is closed, so that the stratum keeps a certain flow conductivity. Therefore, the migration position of the proppant particles in the fracture greatly influences the final yield increasing effect, and the research on the migration rule of the proppant in the fracture has great significance for guiding hydraulic fracturing construction.

At present, the research on the migration of a proppant in the hydraulic fracturing process mainly utilizes a large-scale visual flat plate experiment means, sand carrying liquid containing the proppant is pumped into a visual flat plate, and the movement rule of the sand carrying liquid is researched through the observation of the proppant conveying process in the flat plate. With the development of proppant visualization plate technology, the formation conditions that can be simulated by a plate experiment are gradually increased, and the experimental research for simulating the filtration loss of fracturing fluid in the formation is an important development of the plate experiment device in the recent period.

The prior art CN206892055U discloses a slickwater sand-carrying experiment simulation device capable of regulating and controlling filtration loss, which is used for simulating filtration loss by opening a hole on a single surface of a flat plate and enabling fluid to flow out of the hole. The inventor finds out in the experimental process that the simulation of fluid loss through the openings can cause the mutation of a local flow field as shown in fig. 1, the uniform fluid loss of the fracturing fluid in a homogeneous reservoir layer cannot be effectively and truly reflected, and then the laying form of the proppant in the fracture under the condition of the fluid loss can not be effectively shown.

Disclosure of Invention

Aiming at the problems, the invention aims to provide a visual flat plate and a conveying experimental device which can realize the simulation of the influence of the uniform filtration loss of fracturing fluid on the conveying of the propping agent in the fracturing process of a homogeneous reservoir, so that the local flow field mutation is prevented, and the migration condition of the propping agent under the filterable homogeneous reservoir is effectively and truly reflected.

The technical scheme of the invention is as follows:

on one hand, the invention provides a flat plate for simulating the influence of even reservoir fluid loss on proppant paving, which comprises a first visual flat plate and a second visual flat plate, wherein the upper end of the first visual flat plate is connected with the upper end of the second visual flat plate through a first sealing element, the lower end of the first visual flat plate is connected with the lower end of the second visual flat plate through a second sealing element, the left end of the first visual flat plate is connected with the left end of the second visual flat plate through a third sealing element, a fluid inlet is arranged on the third sealing element, the right end of the first visual flat plate is connected with the right end of the second visual flat plate through a fourth sealing element, a fluid outlet is arranged on the fourth sealing element, and a channel for simulating cracks is formed among the first visual flat plate, the second visual flat plate, the first sealing element, the second sealing element, the third sealing element and the fourth sealing element, the first visualization flat plate is provided with a plurality of drain holes communicated with the crack channel, the inner surface of the first visualization flat plate is provided with a filter screen covering all the drain holes, and the aperture of the filter holes of the filter screen is smaller than the size of the proppant particles.

Preferably, the plurality of drainage holes are distributed in an array on the first visualization flat plate.

Preferably, the filter screen is a stainless steel filter screen.

Preferably, the filter screens are composed of m groups of first filter screens, m is a natural number greater than or equal to 2, the first filter screens are composed of n layers of second filter screens, and n is a natural number greater than or equal to 1.

Preferably, the second screen openings of the same group are the same size.

Preferably, two adjacent groups of the first filter screen filtering holes are arranged in a staggered mode.

Preferably, the first screen aperture is smaller closer to the first visualization plate.

Preferably, waterproof cushion blocks are arranged at the left end and the right end of the filter screen.

On the other hand, the invention also provides an experimental device for simulating the influence of the uniform filtration of the reservoir on the laying of the propping agent, which comprises any one of the flat plates for simulating the influence of the uniform filtration of the reservoir on the laying of the propping agent, wherein the left end of the flat plate is connected with a liquid inlet system, the liquid inlet system comprises a sand mixing tank, a delivery pump and an inlet shaft which are sequentially connected, the side wall of the inlet shaft is provided with a simulated perforation, the simulated perforation is connected with the liquid inlet of the flat plate, a pipeline connecting the inlet shaft and the delivery pump is provided with a flowmeter and a pressure gauge, and a pipeline connecting the delivery pump and the sand mixing tank is provided with a valve;

the right end of the flat plate is connected with a waste liquid collecting system, the waste liquid collecting system comprises an outlet shaft and a waste liquid collecting tank which are connected, the outlet shaft is connected with a liquid outlet of the flat plate, and a pipeline connecting the outlet shaft and the waste liquid collecting tank is provided with a pressure gauge;

the drainage hole is connected with a filtration system, the filtration system comprises a suction pump and a filtration fluid collecting tank which are connected, the input end of the suction pump is connected with the drainage hole, and a valve, a pressure gauge and a flow meter are sequentially arranged on a pipeline connecting the suction pump and the drainage hole.

Preferably, the delivery pump is a screw pump.

Preferably, a stirring mechanism, a water inlet pipeline and a sand inlet pipeline are arranged in the sand mixing tank.

Compared with the prior art, the invention has the beneficial effects that:

the flat plate can be used for simulating the influence of uniform filtration of the fracturing fluid of a homogeneous reservoir on the conveying and laying of the propping agent, and the filtering net with the filtration pore diameter smaller than the size of the propping agent particles is arranged on the inner surface of the flat plate where the drainage holes are positioned, so that the fracturing fluid is uniformly filtered, and the real migration condition of the propping agent under the reservoir which can be filtered is reflected. The experiment device can be used for simulating a proppant conveying experiment, the influence of uniform filtration loss of fracturing fluid of a homogeneous reservoir on proppant conveying and laying can be simulated through the experiment device, the whole process of proppant conveying is simulated through the flat plate, the liquid inlet system, the waste liquid collecting system and the filtration loss system, uniform filtration loss of the fracturing fluid is realized through the flat plate, and the problem of local flow field mutation existing in the conventional device is solved, so that the real simulation of the influence of the filtration loss of the fracturing fluid in a homogeneous stratum on proppant conveying and transporting in the hydraulic fracturing process is realized, and the experiment device has guiding significance for actual engineering.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic view of a flow field of a prior art simulated proppant delivery process;

FIG. 2 is a schematic top view of a flat plate according to the present invention simulating the effect of uniform reservoir fluid loss on proppant placement;

FIG. 3 is a schematic view of a partial structure of a flat screen for simulating the effect of uniform fluid loss from a reservoir on proppant placement according to the present invention;

FIG. 4 is a schematic elevation view of a flat plate for simulating the effect of uniform reservoir fluid loss on proppant placement according to the present invention;

FIG. 5 is a schematic structural view of an embodiment of a plate for simulating the effect of uniform reservoir fluid loss on proppant placement according to the present invention;

FIG. 6 is a schematic diagram of another embodiment of a flat screen according to the present invention simulating the effect of reservoir uniformity fluid loss on proppant placement;

FIG. 7 is a schematic diagram of another embodiment of a flat screen according to the present invention simulating the effect of reservoir uniformity fluid loss on proppant placement;

FIG. 8 is a schematic diagram of another embodiment of a flat screen according to the present invention simulating the effect of reservoir uniformity fluid loss on proppant placement;

FIG. 9 is a schematic structural diagram of an experimental apparatus for simulating the effect of uniform fluid loss from a reservoir on proppant placement according to the present invention;

FIG. 10 is a schematic view of a partial structure of a fluid loss system of an experimental apparatus for simulating the effect of uniform fluid loss from a reservoir on proppant placement according to the present invention.

FIG. 11 is a schematic view of a flow field in an experimental process of the experimental device for simulating the influence of uniform fluid loss of a reservoir on proppant placement.

Reference numbers in the figures:

1-plate, 101-first visual plate, 102-second visual plate, 103-sealing element I, 104-sealing element II, 105-sealing element III, 106-liquid inlet, 107-sealing element IV, 108-water discharging hole, 109-filter screen, 109A-outer filter screen, 109B-middle filter screen, 109C-inner filter screen, 109M-first filter screen, 109N-second filter screen, 110-filtering hole, 111-waterproof cushion block, 2-sand mixing tank, 3-conveying pump, 4-inlet shaft, 5-simulated perforation, 6-flowmeter, 7-valve, 8-outlet shaft, 9-waste liquid collecting tank, 10-pressure gauge, 11-suction pump, 12-filtrate collecting tank, 13-stirring mechanism, 14-water inlet pipeline, 15-sand inlet pipeline and 16-bolt.

Detailed Description

The invention is further illustrated with reference to the following figures and examples.

It should be noted that, in the present application, the embodiments and the technical features of the embodiments may be combined with each other without conflict.

It is noted that, unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

In the present invention, the terms "first", "second", and the like are used for distinguishing similar objects, but not for describing a particular order or sequence order, unless otherwise specified. It is to be understood that the terms so used; the terms "upper", "lower", "left", "right", and the like are used generally with respect to the orientation shown in the drawings, or with respect to the component itself in a vertical, or gravitational orientation; likewise, "inner", "outer", and the like refer to the inner and outer relative to the contours of the components themselves for ease of understanding and description. The above directional terms are not intended to limit the present invention.

In order to solve the problem that the migration condition of a proppant under a leachable reservoir cannot be effectively and truly reflected due to sudden change of a local flow field in the prior art, the invention and the embodiment of the invention provide a flat plate for simulating the influence of uniform reservoir filtration on the laying of the proppant. As shown in fig. 2-8, the flat plate 1 includes a first visualization flat plate 101 and a second visualization flat plate 102, an upper end of the first visualization flat plate 101 is connected to an upper end of the second visualization flat plate 102 through a first sealing member 103, a lower end of the first visualization flat plate 101 is connected to a lower end of the second visualization flat plate 102 through a second sealing member 104, a left end of the first visualization flat plate 101 is connected to a left end of the second visualization flat plate 102 through a third sealing member 105, a liquid inlet 106 is disposed on the third sealing member 105, a right end of the first visualization flat plate 101 is connected to a right end of the second visualization flat plate 102 through a fourth sealing member 107, a liquid outlet is disposed on the fourth sealing member 107, and a channel simulating a crack is formed among the first visualization flat plate 101, the second visualization flat plate 102, the first sealing member 103, the second sealing member 104, the third sealing member 105, and the fourth sealing member 107, the first visualization flat plate 101 is provided with a plurality of water drainage holes 108 communicated with the crack channel, the inner surface of the first visualization flat plate 101 is provided with a filter screen 109 covering all the water drainage holes 108, and the aperture of the filter holes 110 of the filter screen 109 is smaller than the size of the proppant particles.

In a specific embodiment, the plate 1 is vertically positioned to simulate a vertical crack, and the first seal 103 is removably disposed between the upper ends of the first visualization plate 101 and the second visualization plate 102.

Optionally, the first sealing element 103 is long, the upper ends of the inner surfaces of the first visualization flat plate 101 and the second visualization flat plate 102 opposite to each other are provided with an insertion slot for placing the first sealing element 103, and a sealing ring is arranged between the insertion slot and the first sealing element 103. Preferably, the sealing ring is C-shaped. The proppant can be prevented from overflowing from the upper end of the simulated fracture channel by the sealing ring and the first sealing element 103.

In a specific embodiment, the first sealing element 103 and the second sealing element 104 are elastic waterproof components such as rubber cylinders, and the upper and lower ends of the first visualization flat plate 101 and the second visualization flat plate 102 are fixedly connected through the rubber cylinders. In actual use, the distance between the first visualization flat plate 101 and the second visualization flat plate 102 can be adjusted by adjusting the pressure applied to the first visualization flat plate 101 or the second visualization flat plate 102 to the inside of the fracture channel, so as to simulate the fluid loss condition of the fracturing fluid under the condition of proppant migration of fractures with different widths.

In a specific embodiment, the plurality of drainage holes 108 are distributed in an array on the first visualization flat plate 101.

Alternatively, the drainage holes 108 are arranged in a plurality of rows and columns.

Alternatively, the row pitch and the column pitch of the drain holes 108 are equal.

Optionally, the row spacing of the drain holes 108 is greater than or less than the column spacing of the drain holes 108.

In a specific embodiment, the filter screen 109 is a stainless steel filter screen which is capable of resisting pressure, abrasion and corrosion, a ceramic proppant is usually used as a proppant used in the oil fracturing process, the hardness is high, the stainless steel filter screen is capable of resisting abrasion, and the service life of the filter screen 109 is prolonged.

In a specific embodiment, the screen 109 is provided as a layer.

In another specific embodiment, the filter screens 109 are composed of M groups of first filter screens 109M, where M is a natural number greater than or equal to 2, the first filter screens 109M are composed of N layers of second filter screens 109N, and N is a natural number greater than or equal to 1. Optionally, the filtering holes 110 of each layer of the second filtering net 109N are the same in size, and the filtering holes 110 of the two adjacent groups of the first filtering nets 109M are arranged in a staggered manner. The fracturing fluid flow field sudden change is slowed down through gaps among each group of first filter screens 109M, gaps among each layer of second filter screens 109N and filter holes 110 of each layer of filter screens, so that the filtration is uniform, and the migration condition of the proppant under the filterable reservoir in the actual working condition is simulated really and effectively. The number of layers of the second filter screens 109N or the number of groups of the first filter screens 109M can be adjusted to adjust the effect of uniform filter loss of the filter screens.

In a specific embodiment, the filter screen 109 is composed of a group of first filter screens 109M, the first filter screens 109M are composed of three layers of second filter screens 109N, and the second filter screens 109N are distributed from being close to the first visualization flat plate 101 to being far from the first visualization flat plate 101, and are respectively an outer filter screen 109A, a middle filter screen 109B, and an inner filter screen 109C. Each layer of filter screen 109 is provided with the same number of filter holes 110, and the filter holes 110 of each layer of filter screen 109 are arranged in multiple rows and multiple columns.

Optionally, the filtering holes 110 of each layer of the filter screen 109 have the same aperture, and the filtering holes 110 of the middle layer of the filter screen 109B are respectively distributed in a staggered manner with the filtering holes 110 of the outer layer of the filter screen 109A and the filtering holes 110 of the inner layer of the filter screen 109C.

Alternatively, the apertures of the filter holes 110 of each layer of the filter screens 109 are sequentially increased from the outer layer of the filter screen 109A to the middle layer of the filter screen 109B to the inner layer of the filter screen 109C. Alternatively, the row spacing and the column spacing of the filtering holes 110 of each layer of the filtering net 109 are sequentially reduced, and the centers of the filtering holes 110 in the same row and the same column are positioned on the same central axis.

In another specific embodiment, the filter screens 109 are composed of three groups of first filter screens 109M, the first filter screens 109M are composed of three layers of second filter screens 109N, the filter holes 110 of each layer of second filter screens 109N are the same in size, and the filter holes 110 of the first filter screens 109M of two adjacent groups are staggered.

Optionally, the apertures 110 of each group of first sieves 109M are the same, or the apertures 110 of the first sieves 109M closer to the first visualization plate 101 are smaller.

In a specific embodiment, the left end and the right end of the filter screen 109 are provided with waterproof spacers 111, and the waterproof spacers 111 can prevent proppant from directly flowing to the drainage holes 108 from a gap between the first visualization flat plate 101 and the filter screen 109 after entering, and a gap between the filter screen 109 and the filter screen 109 when multiple groups or multiple layers of filter screens are used, so that a uniform fluid loss effect is reduced.

Optionally, the waterproof pad 111 is made of a rubber material.

Optionally, the waterproof pad 111 is made of a metal material. Preferably, stainless steel is used.

In a specific embodiment, the screen is affixed to the inner surface of the first visualization plate 101 by an adhesive. In another embodiment, the screen is fixed to the inner surface of the first visualization plate 101 by fasteners such as screws.

As shown in fig. 9-10, the present invention further provides an experimental apparatus for simulating the influence of uniform reservoir fluid loss on proppant placement, including any one of the above-mentioned flat plate 1, the left end of the flat plate 1 is connected to a fluid intake system, the fluid intake system includes a sand mixing tank 2, a delivery pump 3, and an inlet shaft 4, which are connected in sequence, a simulated perforation 5 is provided on the sidewall of the inlet shaft 4, the simulated perforation 5 is connected to a fluid intake 106 of the flat plate 1, a flow meter 6 and a pressure gauge 10 are provided on a pipeline connecting the inlet shaft 4 and the delivery pump 3, and a valve 7 is provided on a pipeline connecting the delivery pump 3 and the sand mixing tank 2;

the right end of the flat plate 1 is connected with a waste liquid collecting system, the waste liquid collecting system comprises an outlet shaft 8 and a waste liquid collecting tank 9 which are connected, the outlet shaft 8 is connected with a liquid outlet of the flat plate 1, and a pipeline connecting the outlet shaft 8 and the waste liquid collecting tank 9 is provided with a pressure gauge 10;

the drainage hole 108 is connected with a fluid loss system, the fluid loss system comprises a suction pump 11 and a fluid loss collection tank 12 which are connected, the input end of the suction pump 11 is connected with the drainage hole 108, and a valve 7, a pressure gauge 10 and a flow meter 6 are sequentially arranged on a pipeline connecting the suction pump 11 and the drainage hole 108.

In a particular embodiment, the plate 1 is placed vertically simulating a vertical crack.

In another specific embodiment, the plate 1 is placed horizontally simulating a horizontal crack.

In a specific embodiment, the entry well bore 4 is the seal three 105, and the simulated perforation 5 of the entry well bore 4 is the fluid inlet 106 of the seal three 105.

Optionally, the entry well bore 4 is connected to the first visualization plate 101 and the second visualization plate 102 by bolts 16.

In one specific embodiment, the exit well bore 8 is the seal four 107.

Optionally, the exit well bore 8 is connected to the first visualization plate 101 and the second visualization plate 102 by bolts 16.

In a specific embodiment, the conveying pump 3 adopts a screw pump, and the screw pump has stable pressure and can continuously and uniformly discharge liquid in the conveying process, so that the proppant conveying experiment is smoother.

In a specific embodiment, a stirring mechanism 13, a water inlet line 14 and a sand inlet line 15 are arranged in the sand mixing tank 2.

In a specific embodiment, the waste liquid collecting tank and/or the filtrate collecting tank are connected with the sand mixing tank through pipelines, so that the liquid can be recycled, the waste is reduced, and the resources are saved.

When the experimental device for simulating the influence of the uniform fluid loss of the reservoir on the laying of the proppant is used, the experimental device comprises the following components:

(1) firstly, vertically placing the flat plate to simulate a vertical crack or horizontally placing the flat plate to simulate a horizontal crack according to the experiment requirement;

(2) connecting the components according to a schematic structural diagram of an experimental device for simulating the influence of the uniform fluid loss of the reservoir on the laying of the proppant as shown in FIG. 9;

(3) checking the sealing performance of an experimental device for simulating the influence of the uniform fluid loss of the reservoir on the spreading of the propping agent, and if a leaking part exists, reconnecting the leaking part until the whole experimental device keeps good sealing performance;

(4) preparing a sand liquid for simulating uniform filtration of homogeneous reservoir fracturing fluid in a sand mixing tank according to experimental requirements, adding sand and liquid into the sand mixing tank through a water inlet pipeline and a sand inlet pipeline, and uniformly mixing the sand and the liquid through a stirring mechanism to prepare the experimental sand liquid for standby;

(5) opening a valve between the sand mixing tank and the delivery pump, and starting the delivery pump to enable sand liquid in the sand mixing tank to enter an inlet shaft through a pipeline;

(6) allowing sand fluid to enter the plate through simulated perforations of the entry well bore;

(7) opening a valve between the suction pump and the drain hole, starting the suction pump, and simulating the filtration loss condition of the fracturing fluid in the crack channel;

(8) recording data such as time, pressure, flow and the like in the experimental process;

(9) and (6) processing data to obtain the fluid loss condition of the fracturing fluid in the simulated fracture channel.

In a specific embodiment, the method is used for simulating the filtration loss condition of the fracturing fluid in a fracture channel, the change of a flow field of the fracturing fluid in the transportation process is shown in fig. 11, and as can be seen from fig. 11, the method can realize the uniform filtration loss of the fracturing fluid in the process of simulating the fracturing of a homogeneous reservoir and prevent the local flow field from protruding.

Although the present invention has been described with reference to a preferred embodiment, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (10)

1. The flat plate is characterized by comprising a first visual flat plate and a second visual flat plate, wherein the upper end of the first visual flat plate is connected with the upper end of the second visual flat plate through a first sealing element, the lower end of the first visual flat plate is connected with the lower end of the second visual flat plate through a second sealing element, the left end of the first visual flat plate is connected with the left end of the second visual flat plate through a third sealing element, a liquid inlet is formed in the third sealing element, the right end of the first visual flat plate is connected with the right end of the second visual flat plate through a fourth sealing element, a liquid outlet is formed in the fourth sealing element, and a channel for simulating cracks is formed among the first visual flat plate, the second visual flat plate, the first sealing element, the second sealing element, the third sealing element and the fourth sealing element, the first visualization flat plate is provided with a plurality of drain holes communicated with the crack channel, the inner surface of the first visualization flat plate is provided with a filter screen covering all the drain holes, and the aperture of the filter holes of the filter screen is smaller than the size of the proppant particles.

2. The plate of claim 1, wherein the plurality of drainage holes are distributed in an array on the first visualization plate.

3. The flat plate for simulating the effect of uniform reservoir fluid loss on proppant placement as set forth in claim 1, wherein said screen is a stainless steel screen.

4. The flat panel for simulating the effect of uniform reservoir fluid loss on proppant placement according to claim 1, wherein the screens are comprised of m groups of first screens, m being a natural number greater than or equal to 2, the first screens being comprised of n layers of second screens, n being a natural number greater than or equal to 1.

5. The plate of claim 4, wherein the second screen openings of a same set are the same size.

6. The flat plate for simulating the effect of uniform reservoir fluid loss on proppant placement as set forth in claim 5, wherein adjacent sets of first screen openings are staggered.

7. The plate for simulating the effect of uniform reservoir fluid loss on proppant placement according to any of claims 4-6, wherein the first screen hole pore size decreases closer to the first visualization plate.

8. The flat plate for simulating the influence of uniform reservoir fluid loss on proppant placement as set forth in any one of claims 1-6, wherein waterproof pads are provided at the left and right ends of said screen.

9. The flat plate for simulating the influence of uniform reservoir fluid loss on proppant placement as set forth in claim 7, wherein waterproof pads are provided on the left and right ends of said screen.

10. An experimental apparatus for simulating the effect of reservoir homogeneous fluid loss on proppant placement, comprising a plate according to any one of claims 1 to 9,

the left end of the flat plate is connected with a liquid inlet system, the liquid inlet system comprises a sand mixing tank, a delivery pump and an inlet shaft which are sequentially connected, a simulated perforation is arranged on the side wall of the inlet shaft, the simulated perforation is connected with a liquid inlet of the flat plate, a flow meter and a pressure gauge are arranged on a pipeline connecting the inlet shaft and the delivery pump, and a valve is arranged on a pipeline connecting the delivery pump and the sand mixing tank;

the right end of the flat plate is connected with a waste liquid collecting system, the waste liquid collecting system comprises an outlet shaft and a waste liquid collecting tank which are connected, the outlet shaft is connected with a liquid outlet of the flat plate, and a pipeline connecting the outlet shaft and the waste liquid collecting tank is provided with a pressure gauge;

the drainage hole is connected with a filtration system, the filtration system comprises a suction pump and a filtration fluid collecting tank which are connected, the input end of the suction pump is connected with the drainage hole, and a valve, a pressure gauge and a flow meter are sequentially arranged on a pipeline connecting the suction pump and the drainage hole.

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