Proppant migration visual simulation system

Abstract

The invention belongs to the technical field of oil and gas reservoir exploitation, and discloses a propping agent migration visual simulation system which comprises a crack simulation assembly, a pressurization assembly, a filtration simulation assembly, an injection assembly and a monitoring assembly. The crack simulation assembly comprises transparent simulation plates, penetrating through holes are formed in the simulation plates, the two simulation plates abut against each other oppositely, and a gap is formed between the two simulation plates; the pressurizing assembly is connected with the analog board so as to pressurize the analog board; the filtration simulation assembly comprises two filtration plates, cavities are formed in the filtration plates, the cavities are communicated with the gaps, and the cavities can be filled with gravel; the injection assembly is connected with one of the through holes so as to inject a propping agent into the gap between the two simulation plates; the monitoring assembly comprises an image monitoring part, and the image monitoring part monitors the migration process of the proppant in the gap and provides a basis for research on the migration law of the proppant; the filtration simulation assembly can simulate the filtration effect of natural fractures, and a research basis can be provided for the relation between migration and filtration effect of the proppant.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas reservoir exploitation, and particularly to a visualization simulation system for proppant migration. Background Art

[0002] Hydraulic fracturing is to use a ground high-pressure pump to inject a fracturing fluid with a relatively high viscosity into the oil reservoir through the wellbore. When the injection rate of the fracturing fluid exceeds the absorption capacity of the oil reservoir, a very high pressure is formed on the bottom oil reservoir of the well. When this pressure exceeds the fracture pressure of the oil reservoir rock near the bottom of the well, the oil reservoir will be fractured and cracks will be generated. In order to keep the fractured cracks open, a sand-carrying fluid with proppants is then injected into the oil reservoir, so that while the cracks continue to extend forward, the already fractured cracks can be supported and prevented from closing, forming cracks with high conductivity.

[0003] After the hydraulic fracturing forms cracks, the cracks need to be supported by proppants to prevent the cracks from automatically closing after the fracturing ends, which affects the fracturing effect. The migration of proppants in the natural fracture network affects the support effect of the cracks and the conductivity of oil and gas in the cracks. The natural fracture morphology is complex, and it is difficult to measure the migration of proppants in engineering. Therefore, a visualization simulation system for proppant migration is needed to explore. Summary of the Invention

[0004] The purpose of the present invention is to provide a visualization simulation system for proppant migration, which can more intuitively simulate the proppant migration and provide a basis for the study of proppant migration laws.

[0005] To achieve this purpose, the present invention adopts the following technical solutions:

[0006] A visualization simulation system for proppant migration, comprising:

[0007] A fracture simulation component, including a transparent simulation plate, through holes are provided on the simulation plate, the two simulation plates are abutted against each other relatively, and a gap is provided between the two simulation plates to simulate natural fractures;

[0008] A pressurizing component, the pressurizing component is connected to the simulation plate to pressurize the simulation plate;

[0009] A filtration loss simulation component, including two filtration loss plates, cavities are provided in the filtration loss plates, the cavities communicate with the gap, and the cavities can be filled with sand and gravel to simulate the formation filtration loss environment;

[0010] An injection component, the injection component is connected to one of the through holes to inject proppants into the gap;

[0011] A monitoring component, including an image monitoring device, the image monitoring device monitors the migration process of the proppants in the gap in real time.

[0012] Preferably, the crack simulation assembly further includes a gasket which is clamped between the two simulation plates and surrounds the edges of the simulation plates to form the gap between the two simulation plates. An outlet is provided on the gasket to connect to the fluid loss simulation assembly.

[0013] Preferably, the gasket is concave, and the two gaskets are arranged opposite to each other at intervals.

[0014] Preferably, the pressurizing assembly includes two opposite first pressurizing plates which are transparent plates. The two first pressurizing plates can approach or separate from each other. The two first pressurizing plates respectively abut against the simulation plates. A first pipe is provided on the first pressurizing plate, and the first pipe corresponds to the through hole. One of the first pipes is connected to the injection assembly.

[0015] Preferably, the pressurizing assembly further includes two opposite second pressurizing plates and two opposite third pressurizing plates. The two second pressurizing plates can approach or separate from each other. The two third pressurizing plates can approach or separate from each other. The two second pressurizing plates are located on the upper and lower sides of the simulation plate. The two third pressurizing plates are located on the left and right sides of the simulation plate. Liquid passing holes are provided on the third pressurizing plates, and the fluid loss plate communicates with the gap through the liquid passing holes.

[0016] Preferably, a liquid passing joint is provided on the third pressurizing plate. The liquid passing joint is sealingly connected to the liquid passing hole. The fluid loss plate has a second pipe which communicates with the liquid passing joint to connect the gap with the cavity.

[0017] Preferably, a recovery bucket is further provided, and the recovery bucket is connected to the first pipe opposite to the injection assembly.

[0018] Preferably, a liquid outlet is provided on the fluid loss plate, and a flowmeter is connected to the liquid outlet.

[0019] Preferably, the injection assembly includes a mixer which communicates with a fluid storage tank and a proppant storage tank. The mixer also communicates with a driving pump, and the driving pump is connected to the through hole.

[0020] Preferably, the monitoring assembly further includes an image processor which is connected to the image monitoring member to draw the state, distribution and movement track of each particle of the proppant.

[0021] Advantages of the present invention:

[0022] The crack simulation component can simulate natural cracks, and the pressurizing component can pressurize the simulation plate in the crack simulation component to simulate the crack closure pressure. The injection component injects proppant into the crack. Subsequently, the migration process and state of the proppant can be directly observed, and the morphology of the proppant can be clearly seen. Moreover, the migration of the proppant is recorded by the image monitoring component, providing a basis for the study of the proppant migration law. In addition, the filtration simulation component can simulate the filtration effect of natural cracks, making the proppant migration data more realistic and providing a research basis for the relationship between the migration and filtration effect of the proppant. Brief Description of the Drawings

[0023] Figure 1 is a schematic diagram of the proppant migration visualization simulation system of the present invention;

[0024] Figure 2 is a schematic diagram of the connection between the filtration simulation component and the crack simulation component in the proppant migration visualization simulation system of the present invention;

[0025] Figure 3 is an image in which the image processor binarizes the proppant migration law in the proppant migration visualization simulation system of the present invention.

[0026] In the figure:

[0027] 1. Crack simulation component; 11. Simulation plate; 12. Through hole; 13. Gasket; 14. Outlet;

[0028] 2. Pressurizing component; 21. First pressure plate; 22. Hydraulic mechanism; 23. Second pressure plate; 24. Third pressure plate; 25. Liquid passing joint;

[0029] 3. Filtration simulation component; 31. Filtration plate; 32. Flowmeter;

[0030] 4. Injection component; 41. Mixer; 42. Proppant storage tank; 43. Fluid storage tank; 44. Driving pump;

[0031] 5. Monitoring component; 51. Image monitoring component; 52. Image processor;

[0032] 6. Recovery bucket;

[0033] 7. Back pressure valve. Detailed Embodiment

[0034] The present invention will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. In addition, it should be noted that for the sake of description, only parts related to the present invention are shown in the drawings, rather than all the structures.

[0035] In the description of the present invention, unless otherwise clearly defined and limited, the terms "connected", "connected to", and "fixed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] In the present invention, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "above and to the right", and "above and to the left" of the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "below and to the right", and "below and to the left" of the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.

[0037] In the description of this embodiment, the orientation or positional relationships such as "above", "below", "left", and "right" are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of description and simplifying the operation, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0038] As Figure 1 and Figure 3 shown, the present invention provides a visualization simulation system for proppant transport, which includes a fracture simulation component 1, a pressurization component 2, a filtration loss simulation component 3, an injection component 4, and a monitoring component 5; the fracture simulation component 1 includes a transparent simulation plate 11, and a through hole 12 is provided on the simulation plate 11. Two simulation plates 11 are abutted against each other relatively, and a gap is provided between the two simulation plates 11 to simulate a natural fracture; the pressurization component 2 is connected to the simulation plate 11 to pressurize the simulation plate 11; the filtration loss simulation component 3 includes two filtration loss plates 31, and a cavity is provided inside the filtration loss plate 31. The cavity communicates with the gap, and the cavity can be filled with sand and gravel to simulate the formation filtration loss environment; the injection component 4 is connected to one of the through holes 12 to inject proppant into the gap between the two simulation plates 11; the monitoring component 5 includes an image monitoring member 51, and the image monitoring member 51 monitors the transport process of the proppant in the gap.

[0039] The crack simulation component 1 can simulate natural cracks, and the pressurizing component 2 can pressurize the simulation plate 11 in the crack simulation component 1 to simulate the crack closure pressure. The injection component 4 injects proppant into the crack. Subsequently, the migration process and state of the proppant can be directly observed through the transparent simulation plate 11, and the morphology of the proppant can be clearly seen. Moreover, the migration of the proppant is recorded by the image monitoring component 51, providing a basis for the study of the proppant migration law. In addition, the filtration simulation component 3 can simulate the filtration effect of natural cracks, making the proppant migration data more realistic and providing a research basis for the relationship between the proppant migration and the filtration effect.

[0040] As Figure 1 and Figure 2 shown, in this embodiment, the transparent simulation plate 11 is made of transparent acrylic plate, and a through-hole 12 is provided on each simulation plate 11. The crack simulation component 1 further includes a gasket 13, and the gasket 13 surrounds the edge of the simulation plate 11. When the two simulation plates 11 are abutted against each other, the gasket 13 is clamped between the two simulation plates 11, thereby forming a gap between the two simulation plates 11 to simulate a natural fissure. The gasket 13 is provided with an outlet 14 to connect to the filtration simulation component 3. Specifically, the gasket 13 is concave, and the two concave gaskets 13 are arranged at intervals relative to each other, so that the interval between the gaskets 13 forms the above-mentioned outlet 14 connecting the filtration simulation component 3. Exemplarily, the gasket 13 is a copper foil gasket. It can be understood that the cracking degree of the crack can be adjusted by using gaskets 13 with different thicknesses, and the crack length and height can be adjusted by using gaskets 13 with different widths. Therefore, different natural cracks can be simulated by replacing different gaskets 13, expanding the scope of application.

[0041] In this embodiment, the pressurizing component 2 includes two opposite first pressurizing plates 21. The first pressurizing plates 21 are also transparent plates, and the migration of the proppant can be observed through the first pressurizing plates 21 and the simulation plate 11. The two first pressurizing plates 21 respectively abut against the simulation plate 11, and the pressure between the two simulation plates 11 is changed by the mutual approach or separation of the two first pressurizing plates 21 to simulate the crack closure pressure. Exemplarily, the first pressurizing plate 21 is connected to a hydraulic mechanism 22 to be able to push the first pressurizing plate 21 to move. In order to be able to inject the proppant, a first tube is provided on the first pressurizing plate 21, and the first tube corresponds to the through-hole 12, so that the simulation plate 11 is connected to the injection component 4 through the first tube. Exemplarily, the first pressurizing plate 21 is made of sapphire material.

[0042] Further, the pressurizing assembly 2 further includes two opposite second pressure plates 23 and two opposite third pressure plates 24. The two second pressure plates 23 are arranged on the upper and lower sides of the simulation plate 11 respectively; the two first pressure plates 21 can approach or move away from each other. The two third pressure plates 24 are located on the left and right sides of the simulation plate 11, and the two third pressure plates 24 can approach or move away from each other; that is, the two first pressure plates 21, the two second pressure plates 23 and the two third pressure plates 24 surround and pressurize the simulation plate 11 to simulate the in-situ stress under the true triaxial condition. In this embodiment, the second pressure plate 23 and the third pressure plate 24 are connected to the hydraulic mechanism 22 to be able to push them to move. Exemplarily, the second pressure plate 23 is made of metal material, and the third pressure plate 24 is an acrylic plate. A liquid passing hole is provided on the third pressure plate 24, and the liquid passing hole communicates with the outlet 14 and then communicates with the gap; in addition, a liquid passing joint 25 is provided on the third pressure plate 24, and the liquid passing joint 25 is sealingly connected to the liquid passing hole. The filter loss plate 31 has a second pipe, and the second pipe is connected to the liquid passing joint 25 to be able to connect the gap with the cavity in the filter loss plate 31, so as to connect the crack with the filter loss simulation assembly 3 and simulate the formation filter loss environment. Specifically, the liquid passing joint 25 is sealingly connected to the second pipe. It should be noted that the sand ratio in the cavity of the filter loss plate 31 can be set according to experimental requirements and is not specifically limited. Further, a liquid outlet is provided on the filter loss plate 31, and the liquid outlet is connected to a flowmeter 32, so as to be able to reflect the filter loss situation. Exemplarily, the filter loss plate 31 is made of metal material.

[0043] As Figure 1 shown, in this embodiment, the injection assembly 4 includes a mixer 41. The mixer 41 is respectively connected to a proppant storage tank 42 for storing proppant and a fluid storage tank 43 for storing sand-carrying fluid. The sand-carrying fluid and the proppant are mixed in the mixer 41 to form a sand-carrying fluid with proppant. Exemplarily, the proppant can be, but is not limited to, one or several of sand, ceramsite or resin materials; the sand-carrying fluid can directly use fracturing fluid. The mixer 41 is connected to a driving pump 44, and the driving pump 44 is connected to a first pipe, so as to be able to transport the sand-carrying fluid with proppant. In addition, the first pipe on the first pressure plate 21 opposite to the driving pump 44 is connected to a recovery bucket 6, that is, one of the two first pipes is connected to the driving pump 44, and the other is connected to the recovery bucket 6, so as to recover part of the outflowing sand-carrying fluid. In addition, the recovery bucket 6 can be directly connected to the mixer 41 to be able to recycle. Further, a back pressure valve 7 is provided between the first pipe and the recovery bucket 6 to control the flow pressure.

[0044] In this embodiment, the monitoring component 5 includes an image monitoring member 51 and an image processor 52. The image processor 52 is connected to the image monitoring member 51. The image monitoring member 51 monitors the migration process of the proppant in the gap in real time and records and feeds back the monitoring process to the image processor 52, so that the state, distribution and movement trajectory of each particle of the proppant can be drawn by the image processor 52. Exemplarily, the image monitoring member 51 is a high-speed camera, and the image processor 52 is a computer capable of processing images. As Figure 3 shown, after the high-speed camera transmits the captured image of the proppant migrating in the gap to the computer, the computer performs binary image processing, and then the computer can label each particle of the proppant to study the state, distribution and movement trajectory of each proppant particle.

[0045] It should be noted here that multiple groups of the fracture simulation component 1, the pressurization component 2, the fluid loss simulation component 3 and the monitoring component 5 can be set. That is, multiple groups are connected in series through the first pipe, and the injection component 4 is connected to one end of the first pipe, and the recovery bucket 6 is connected to the other end of the first pipe; the specifications of the fractures in multiple groups can be the same or different, so that multiple groups of data can be studied at one time.

[0046] The following will be further explained and illustrated based on a set of experimental data:

[0047] Three groups of the fracture simulation component 1, the pressurization component 2, the fluid loss simulation component 3 and the monitoring component 5 can be set to form three fractures. By setting different gaskets 13, the fracture length in the first group is 50 cm, the fracture height is 20 cm, and the crack opening is 0.05 mm; the fracture length in the second group is 40 cm, the fracture height is 15 cm, and the crack opening is 0.08 mm; the fracture length in the third group is 60 cm, the fracture height is 20 cm, and the crack opening is 0.1 mm.

[0048] The proppant is selected as sand and gravel, the displacement of the sand-carrying fluid is selected as 10 ml / min, the sand ratio is 100 kg / m3, the size of the sand and gravel is 70 mesh, and the sand-carrying fluid and the sand and gravel are fully stirred in the mixer 41 and then pumped into the system by the driving pump 44, and the pumping pressure is 4 MPa;

[0049] Pressures are applied to the simulation plate 11 through the first pressure plate 21, the second pressure plate 23 and the third pressure plate 24; the pseudo in-situ stress of the third pressure plate 24 is 50 MPa, the force-simulated in-situ stress of the second pressure plate 23 is 40 MPa, and the stress direction of the first pressure plate 21 is perpendicular to the fracture, and the simulated fracture closure pressure is 20 MPa;

[0050] After the driving pump 44 is turned on, a part of the proppant-carrying fluid is injected into the fracture through the first pipe, a part of the proppant-carrying fluid enters the fracture in the lower group through another first pipe, and another part of the proppant-carrying fluid enters the filtration loss simulation assembly 3. The whole migration process is recorded by a high-speed camera with a frame rate of 2000 frames to capture the real-time distribution of the proppant in the proppant-carrying fluid. The information recorded by the high-speed camera is transmitted to a computer for binarization processing, and each particle is numbered to obtain the real-time state, distribution, and movement trajectory information of each proppant particle, so as to further analyze the migration law of the proppant.

[0051] Obviously, the above-mentioned embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limitations on the implementation manners of the present invention. For those of ordinary skill in the art, various obvious changes, re-adjustments, and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A proppant transport visualization simulation system, characterized in that, Including: A crack simulation component (1), including a transparent simulation plate (11), through holes (12) are provided on the simulation plate (11), the two simulation plates (11) are abutted against each other relatively, and a gap is provided between the two simulation plates (11) to simulate natural cracks; A pressurizing component (2), the pressurizing component (2) is connected to the simulation plate (11) to pressurize the simulation plate (11); A filtration loss simulation component (3), including two filtration loss plates (31), cavities are provided inside the filtration loss plates (31), the cavities communicate with the gap, and the cavities can be filled with sand and gravel to simulate the formation filtration loss environment; An injection component (4), the injection component (4) is connected to one of the through holes (12) to inject proppants into the gap; A monitoring component (5), including an image monitoring member (51), the image monitoring member (51) monitors the migration process of the proppants in the gap in real time.

2. The proppant transport visualization simulation system according to claim 1, characterized in that The crack simulation component (1) further includes a gasket (13), the gasket (13) is clamped between the two simulation plates (11) and surrounds the edge of the simulation plate (11) to form the gap between the two simulation plates (11); an outlet (14) is provided on the gasket (13) to connect to the filtration loss simulation component (3).

3. The proppant transport visualization simulation system according to claim 2, wherein The gasket (13) is concave, and the two gaskets (13) are arranged oppositely at intervals.

4. The proppant transport visualization simulation system according to claim 1, wherein The pressurizing component (2) includes two opposite first pressurizing plates (21), the first pressurizing plates (21) are transparent plates, the two first pressurizing plates (21) can approach or move away from each other, the two first pressurizing plates (21) are respectively abutted against the simulation plate (11), a first pipe is provided on the first pressurizing plate (21), the first pipe corresponds to the through hole (12), and one of the first pipes is connected to the injection component (4).

5. The proppant transport visualization simulation system according to claim 4, wherein The pressurizing component (2) further includes two opposite second pressurizing plates (23) and two opposite third pressurizing plates (24), the two second pressurizing plates (23) can approach or move away from each other, the two third pressurizing plates (24) can approach or move away from each other, the two second pressurizing plates (23) are located on the upper and lower sides of the simulation plate (11), the two third pressurizing plates (24) are located on the left and right sides of the simulation plate (11), liquid passing holes are provided on the third pressurizing plates (24), and the filtration loss plates (31) communicate with the gap through the liquid passing holes.

6. The proppant transport visualization simulation system according to claim 5, wherein A liquid passing joint (25) is provided on the third pressurizing plate (24), the liquid passing joint (25) is hermetically connected to the liquid passing hole, and the filtration loss plate (31) has a second pipe, and the second pipe communicates with the liquid passing joint (25) to be able to connect the gap and the cavity.

7. The proppant transport visualization simulation system according to claim 4, wherein A recovery bucket (6) is further provided, and the recovery bucket (6) is connected to the first pipe opposite to the injection component (4).

8. The proppant transport visualization simulation system according to claim 1, wherein A liquid outlet is provided on the filtration loss plate (31), and a flowmeter (32) is connected to the liquid outlet.

9. The proppant transport visualization simulation system according to claim 1, wherein The injection component (4) includes a mixer (41), the mixer (41) is communicated with a fluid storage tank (43) and a proppant storage tank (42), the mixer (41) is further communicated with a driving pump (44), and the driving pump (44) is connected to the through hole (12).

10. The proppant transport visualization simulation system according to claim 1, characterized in that, The monitoring component (5) further includes an image processor (52), and the image processor (52) is connected to the image monitoring member (51) to draw the state, distribution and movement trajectory of each particle of the proppant.

Images