Rock core model outlet end control device and method

Abstract

The invention discloses a core model outlet end control device and method.The device comprises a flow guide plate connected with the outlet end of an experiment core model, a plurality of round holes are formed in the flow guide plate, and the round hole parameters of the flow guide plate are calculated through a granularity control empirical formula; the granularity control of the fluid produced under different reservoir seepage characteristic simulation experiment conditions is realized by controlling the parameters of the circular holes of the guide plate; the flow collecting control module comprises a flow collecting channel, a flow distributing partition plate and a flow guiding outlet which are connected in sequence, the flow collecting channel is used for collecting output fluid flowing out of the outlet end of the flow guiding plate, and the flow distributing partition plate is used for separating the output fluid flowing out of the flow collecting channel; the separated output fluid respectively enters different output fluid outlet channels of the diversion outlet; the device can finely control indexes such as output particle size, position and component of output fluid, can accurately simulate development seepage environments of different types of oil reservoirs, and has a wide application prospect in the field of oil reservoir seepage characteristic research.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas field development experiments, and more specifically, to a control device and method for the outlet end of a core model. Background Art

[0002] To meet the urgent need for building production with scale benefits during the oilfield development process, it is necessary to continuously conduct in-depth research on the key technologies of the efficient development experiments of complex types of reservoirs such as low-permeability and unconsolidated sandstone, and solve special problems such as sand production and gas channeling during different development methods. The development of physical simulation experiments is the basis of oil and gas field development. It can not only provide basic reservoir parameters for work such as reserve calculation of oil and gas reservoirs, compilation of development plans, and reservoir numerical simulation, but also provide a method guarantee for solving many problems encountered in reservoir development. And realizing the control of the outlet end of the core model is the key technical means for accurately carrying out the indoor development seepage simulation experiment of complex types of reservoirs.

[0003] At present, the control function of the model outlet end is extremely single and has strong limitations, mainly concentrated on the use of conventional core parameter tests, and cannot truly simulate the performance effect of the test system for complex types of reservoirs and the seepage characteristics of the test system in the formation, so it is impossible to truly describe the seepage law of the test system in the near-wellbore zone.

[0004] The most widely used existing control of the produced fluid at the outlet end of the core model is achieved by connecting a conventional size model pipeline and valve through a Hassler core holder. It places the core in a circular steel cylinder, and a steel cylindrical plug with a through hole in the center is placed at each end of the core. The through holes of the plugs are respectively connected with pipelines, and the experimental fluid can flow through the pipelines and through the core.

[0005] However, the above-mentioned related technologies still have the following deficiencies: First, the existing outlet control device cannot specifically simulate the reservoir seepage characteristic environment according to the research object; second, the existing technology cannot control a certain parameter of the produced fluid during the specific experiment process.

[0006] Therefore, at the present stage, it is urgent to develop a control device and method for the outlet end of the core model to solve one or more of the above-mentioned existing problems. Summary of the Invention

[0007] An object of the present invention is to provide a new technical solution for a control device and method for the outlet end of a core model.

[0008] According to a first aspect of the present invention, there is provided an outlet end device of a core model, the device comprising:

[0009] A deflector plate, which is used to connect the outlet end of the experimental core model. A plurality of round holes are provided on the deflector plate. The round hole parameters of the deflector plate are calculated by a pre-established particle size control empirical formula. By controlling the round hole parameters of the deflector plate, the particle size control of the produced fluid under the simulation experiment conditions of different reservoir seepage characteristics is realized;

[0010] A flow collection control module, which is connected to the outlet end of the deflector plate;

[0011] The flow collection control module includes a flow collection channel, a flow splitting partition plate and a flow guiding outlet which are connected in sequence. The flow collection channel is used to collect the produced fluid flowing out from the outlet end of the deflector plate. The flow splitting partition plate is used to separate the produced fluid flowing out from the flow collection channel, so that the separated produced fluid enters different produced fluid outlet channels of the flow guiding outlet respectively.

[0012] Optionally, according to the analysis of the lithology and pore structure of the target reservoir, comprehensively considering the factors of thermodynamic limit behavior, mechanical shear action and pore surface ratio, and establishing a particle size control empirical formula through a large number of indoor seepage experiment results. Then, the round hole parameters of the deflector plate are calculated by the particle size control empirical formula, where the round hole parameters include the round hole diameter and the number of holes.

[0013] Optionally, the round hole diameter of the deflector plate is calculated by the particle size control empirical formula 1, and the particle size control empirical formula 1 is expressed as:

[0014]

[0015] where d 孔 represents the round hole diameter of the deflector plate, with the unit of mm; φ represents the sediment particle size; μ represents the main peak mean value; σ represents the main peak variance; d 50 represents the median particle size, with the unit of mm; R represents the radius of the outlet end of the core model, with the unit of mm.

[0016] Optionally, the number of holes of the deflector plate is calculated by the particle size control empirical formula 2, and the particle size control empirical formula 2 is expressed as:

[0017]

[0018] where N 孔 represents the number of holes; R represents the radius of the outlet end of the core model, with the unit of mm; r 孔 represents the round hole radius, with the unit of mm; m represents the number of layers of round hole distribution.

[0019] Optionally, the round hole diameter of the deflector plate is 3 mm, and the number of holes of the deflector plate is 13.

[0020] Optionally, the aperture of the round holes of the flow deflector is 6 mm, and the number of holes of the flow deflector is 6.

[0021] Optionally, the aperture of the round holes of the flow deflector is 8 mm, and the number of holes of the flow deflector is 4.

[0022] Optionally, the flow collecting channel is of a single specification.

[0023] Optionally, the flow dividing partition has three different specifications to meet the experimental requirements of different displacement modes.

[0024] Optionally, the flow dividing partition is an upper and lower double-channel flow dividing partition, an upper-channel flow dividing partition or a lower-channel flow dividing partition.

[0025] Optionally, there is a circular through hole at each of the upper and lower parts of the flow guiding outlet, and the aperture of the circular through hole is the same as the aperture of the round holes of the flow deflector.

[0026] Optionally, the flow collecting control module further includes a filter plate, the filter plate is arranged between the flow collecting channel and the flow dividing partition, and the particle size screening control of the produced fluid is realized by the filter plates with different filter mesh specifications.

[0027] According to the second aspect of the present invention, there is provided a method for controlling the outlet end of a core model, the method comprising:

[0028] Calculating the aperture and the number of round holes on the flow deflector based on the physical properties of the target reservoir to be studied and using a pre-established particle size control empirical formula to determine the specification of the flow deflector;

[0029] Determining the specification of the flow dividing partition according to the experimental requirements of different displacement modes, wherein the flow dividing partition is an upper and lower double-channel flow dividing partition, an upper-channel flow dividing partition or a lower-channel flow dividing partition;

[0030] Determining the specification of the flow guiding outlet according to the specification of the flow deflector, wherein there is a circular through hole at each of the upper and lower parts of the flow guiding outlet, and the aperture of the circular through hole is the same as the aperture of the round holes of the flow deflector;

[0031] Installing the flow deflector at the outlet end of the experimental core model, and installing a flow collecting control module composed of a sequentially connected flow collecting channel, a flow dividing partition and a flow guiding outlet at the outlet end of the flow deflector;

[0032] Simulating the development seepage environment of different types of oil reservoirs to carry out different reservoir seepage characteristic simulation experiments to realize the control of the production particle size, position and components of the produced fluid.

[0033] Optionally, when the displacement method is gas displacement, an upper channel shunt baffle is used; when the displacement method is the sinking of solids and suspensions, a lower channel shunt baffle is used.

[0034] According to a third aspect of the present invention, there is provided a core model experimental system, including a core model outlet end control device according to any one of the first aspects of the present disclosure.

[0035] According to an embodiment disclosed by the present invention, it has the following beneficial effects:

[0036] The core model outlet end control device of the present invention can finely control the output particle size, position, composition and other indicators of the produced fluid, accurately simulate the development seepage environment of different types of oil reservoirs, broaden the research scope and improve the experimental accuracy when designing the development experimental plan, analyze the main control factors affecting the seepage law, solve problems such as sand production and gas channeling in different development methods such as water flooding, gas flooding, and chemical flooding, and is applicable to the entire life cycle of development in the development of various complex oil and gas fields, especially in the field of research on oil reservoir seepage characteristics, with broad application prospects.

[0037] Through the following detailed description of the exemplary embodiments of the present invention with reference to the accompanying drawings, other features and advantages of the present invention will become clear. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The drawings incorporated in the specification and constituting a part of the specification illustrate embodiments of the present invention and, together with the description, are used to explain the principles of the present invention.

[0039] Figure 1 It is a schematic structural diagram of a core model outlet end control device provided according to an embodiment;

[0040] Figure 2 It is a schematic exploded view of the structure of a core model outlet end control device provided according to an embodiment;

[0041] Figure 3 It is a schematic structural diagram of a deflector in a core model outlet end control device provided according to an embodiment Figure 1 ;

[0042] Figure 4 It is a schematic structural diagram of a deflector in a core model outlet end control device provided according to an embodiment Figure 2 ;

[0043] Figure 5 It is a schematic structural diagram of a deflector in a core model outlet end control device provided according to an embodiment Figure 3 ;

[0044] Figure 6Schematic diagram of the structure of the flow dividing partition in a core model outlet end control device provided according to an embodiment Figure 1 ;

[0045] Figure 7 Schematic diagram of the structure of the flow dividing partition in a core model outlet end control device provided according to an embodiment Figure 2 ;

[0046] Figure 8 Schematic diagram of the structure of the flow dividing partition in a core model outlet end control device provided according to an embodiment Figure 3 ;

[0047] Figure 9 Schematic diagram of the structure of the diversion outlet in a core model outlet end control device provided according to an embodiment Figure 1 ;

[0048] Figure 10 Schematic diagram of the structure of the diversion outlet in a core model outlet end control device provided according to an embodiment Figure 2 ;

[0049] Figure 11 Schematic diagram of the structure of the diversion outlet in a core model outlet end control device provided according to an embodiment Figure 3 ;

[0050] Figure 12 Schematic diagram of the structure of the filter plate in a core model outlet end control device provided according to an embodiment;

[0051] Figure 13 Distribution diagram of reservoir clastic rock grain size samples;

[0052] Figure 14 Decomposition diagram of reservoir clastic rock grain size parent body;

[0053] Figure 15 Experimental permeability relationship diagram of sand production critical conditions.

[0054] Explanation of reference numerals:

[0055] 1 - diversion plate; 11 - round hole;

[0056] 2 - flow - collecting channel;

[0057] 3 - filter plate;

[0058] 4 - flow - dividing partition;

[0059] 5 - diversion outlet; 51 - circular through - hole. Detailed implementation manners

[0060] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that: unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present invention.

[0061] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way a limitation on the present invention or its application or use.

[0062] Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such technologies, methods, and devices should be regarded as part of the specification.

[0063] In all the examples shown and discussed herein, any specific values should be construed as merely exemplary and not as a limitation. Accordingly, other examples of the exemplary embodiments may have different values.

[0064] Embodiment 1:

[0065] See Figure 1-2 As shown, this embodiment provides a control device for the outlet end of a core model. The device includes: a deflector plate 1, which is used to connect the outlet end of the experimental core model. A plurality of round holes 11 are provided on the deflector plate 1. The round hole parameters of the deflector plate 1 are calculated through a pre-established particle size control empirical formula. By controlling the round hole parameters of the deflector plate 1, the particle size control of the produced fluid under the simulation experimental conditions of different reservoir seepage characteristics is realized;

[0066] A flow concentration control module, connected to the outlet end of the deflector plate 1;

[0067] The flow concentration control module includes a flow concentration channel 2, a flow splitting partition 4, and a flow guiding outlet 5 connected in sequence. The flow concentration channel 2 is used to collect the produced fluid flowing out from the outlet end of the deflector plate 1. The flow splitting partition 4 is used to separate the produced fluid flowing out from the flow concentration channel 2, so that the separated produced fluid enters different produced fluid outlet channels of the flow guiding outlet 5 respectively.

[0068] The control device for the outlet end of the core model in this embodiment mainly consists of two parts: a deflector plate and a flow concentration control module. On the one hand, through the deflector plate, the particle size control of the produced fluid under the simulation experimental conditions of different reservoir seepage characteristics is scientifically realized, and the round hole parameters of the deflector plate are accurately calculated by innovatively using the particle size control formula simulating different reservoir physical properties. On the other hand, through different combination usage modes of various components such as the deflector plate and the flow concentration control module, various reservoir seepage environments are simulated, and further control over the particle size accuracy, production position, and components of the produced fluid is realized.

[0069] Optionally, in the core model outlet end control device of this embodiment, based on the lithology and pore structure analysis of the target reservoir, factors such as thermodynamic limit behavior, mechanical shear action, and pore surface ratio are comprehensively considered, and an empirical formula for particle size control is established through a large number of indoor seepage experiment results. Then, the round hole parameters of the flow guiding plate are calculated through the empirical formula for particle size control, where the round hole parameters include the round hole diameter and the number of holes.

[0070] It should be noted that in this embodiment, based on the target reservoir, lithology and pore structure analysis are carried out, factors such as thermodynamic limit behavior, mechanical shear action, and pore surface ratio are comprehensively considered, an empirical formula for particle size control is established through a large number of indoor seepage experiment results, the single-hole diameter and the number of holes of the flow guiding plate are calculated, realizing the simulation of the seepage experiment of glutenite with a complex pore structure, and ensuring the maximum similarity between the indoor displacement experiment and the current situation of oilfield development.

[0071] Optionally, in the core model outlet end control device of this embodiment, the round hole diameter of the flow guiding plate 1 is calculated through the first empirical formula for particle size control, and the first empirical formula for particle size control is expressed as:

[0072]

[0073] where d 孔 represents the round hole diameter of the flow guiding plate, with the unit of mm; φ represents the sediment particle size; μ represents the main peak mean value; σ represents the main peak variance; d 50 represents the median particle size, with the unit of mm; R represents the radius of the core model outlet end, with the unit of mm.

[0074] Optionally, in the core model outlet end control device of this embodiment, the number of holes of the flow guiding plate 1 is calculated through the second empirical formula for particle size control, and the second empirical formula for particle size control is expressed as:

[0075]

[0076] where N 孔 represents the number of holes; R represents the radius of the core model outlet end, with the unit of mm; r 孔 represents the round hole radius, with the unit of mm; m represents the number of layers of round hole distribution.

[0077] In some preferred embodiments, the round hole diameter of the flow guiding plate is 3 mm, and the number of holes of the flow guiding plate is 13.

[0078] Preferably, the round hole diameter of the flow guiding plate is 6 mm, and the number of holes of the flow guiding plate is 6.

[0079] More preferably, the round hole diameter of the flow guiding plate is 8 mm, and the number of holes of the flow guiding plate is 4.

[0080] Specifically, the flow guide plate 1 is the contact end between the outlet end control device of the core model in this embodiment and the experimental core model, which guides the produced fluid of the experiment into this device. Its specifications are specifically designed differently according to the physical properties of the target reservoir to be studied, so as to simulate the reservoir seepage environment to the greatest extent. Refer to Figure 3-5 As shown, it shows the structural schematic diagrams of flow guide plates 1 with different specifications. Figure 3 In [diagram reference 1], the number of round holes on the flow guide plate is relatively large, and the hole diameter of the round holes is relatively small. Figure 4 In [diagram reference 2], the number of round holes on the flow guide plate is 6, and the hole diameter of the round holes is larger than Figure 3 the hole diameter of the round holes in [diagram reference 3]; Figure 5 In [diagram reference 4], the number of round holes on the flow guide plate is 4, and the hole diameter of the round holes is larger than Figure 4 the hole diameter of the round holes in [diagram reference 5].

[0081] Optionally, the flow collecting channel 2 in the outlet end control device of the core model in this embodiment has a single specification. In this embodiment, the function of the flow collecting channel is mainly to collect the produced fluid in the experiment, and it has only one specification. The inlet end of the flow collecting channel 2 in this embodiment is adapted to the outlet end of the flow guide plate 1 and can be connected by a threaded method.

[0082] Optionally, the flow dividing partition 4 in the outlet end control device of the core model in this embodiment is an upper and lower dual-channel flow dividing partition, an upper-channel flow dividing partition, or a lower-channel flow dividing partition.

[0083] Specifically, in this embodiment, the flow dividing partition 4 divides the produced fluid in the experiment and enters different produced fluid outlet channels respectively. Among them, the gas preferentially passes through the upper channel, and solids such as sand grains and suspensions sink and preferentially pass through the lower channel, realizing the control of the production position and components of the produced fluid, meeting the experimental requirements of different displacement methods such as water flooding, gas flooding, and chemical flooding. Therefore, the flow dividing partition 4 has 3 different specifications, respectively realizing different effects of the produced fluid flowing out through both the upper and lower parts simultaneously, only flowing out through the upper channel, and only flowing out through the lower channel. Refer to Figures 6 - 8.

[0084] Optionally, refer to Figure 9-11 As shown, in the outlet end control device of the core model in this embodiment, there is a circular through-hole 51 at both the upper and lower parts of the flow guide outlet 5, and the hole diameter of the circular through-hole 51 is the same as the hole diameter of the round holes on the flow guide plate 1.

[0085] Specifically, in this embodiment, the flow guide outlet guides the produced fluid out of the device, realizing the control of the production position and components of the produced fluid. Its specifications vary according to the flow guide plate. There is a circular through-hole at both the upper and lower parts of the flow guide outlet, and the through-hole diameter is the same as the hole diameter of the round holes on the flow guide plate.

[0086] Optionally, the flow dividing partition has three different specifications to meet the experimental requirements of different displacement methods.

[0087] Optionally, referring to Figure 12 As shown, in the flow collecting control module of the core model outlet end control device of this embodiment, a filter plate 3 is further included. The filter plate 3 is arranged between the flow collecting channel 2 and the flow dividing partition plate 4, and the particle size screening control of the produced fluid is realized through filter plates 3 with different filter mesh specifications.

[0088] Specifically, in this embodiment, the filter plate realizes the particle size screening control of the produced fluid through filter meshes of different specifications, and can be installed and used according to experimental requirements. The specification setting of the filter mesh can refer to the clastic rock sediment particle size range in SY / T 5434-2018 "Methods for Grain Size Analysis of Clastic Rocks", as shown in Table 1.

[0089] Table 1

[0090]

[0091] The flow collecting control module in the core model outlet end control device of this embodiment has the function of collecting and exporting the produced fluid, and specifically includes component modules such as a flow collecting channel, a filter plate, a flow dividing partition plate, and a diversion outlet, and can be assembled and used according to different displacement methods required for experimental seepage simulation.

[0092] The following takes the sand production critical condition experiment of a typical unconsolidated sandstone reservoir as an example for specific description:

[0093] (1) Statistics of reservoir physical property characteristics

[0094] The natural core selected for the experiment is from Huabei Oilfield. The target reservoir to be studied is a medium-high porosity and medium-high permeability reservoir as a whole, with an average porosity of 26.76% and an average permeability of 1039.54 mD. The cementation is weak, the velocity sensitivity is strong, and the mechanical properties decrease significantly after being saturated with water, and it is very easy to produce sand. The sediment particle size curve of the natural core is tested by the SY / T 5434-2018 industry standard, as Figure 13-14 Through the analysis of a large number of experimental results, it can be known that the sediment particle size parameters representing the physical property characteristics of this reservoir are: φ = 2.87, μ = 3.31, σ = 2.88; d 50 = 151.97 μm.

[0095] (2) Particle size control of different reservoir physical property characteristics

[0096] The selected natural core for the experiment has a specification of 25 mm in diameter and 50 mm in length, so the radius R of the core model outlet end is 25 mm. Substitute the sediment particle size parameters representing the physical property characteristics of this reservoir into the above formula (1), and calculate to obtain d 孔 = 3.26 mm, take the absolute value [d 孔 = 3 mm, and it can be known that the round hole diameter of the diversion plate is 3 mm.

[0097] The radius r of the round holes of the flow guide plate 孔 = 1.5 mm, the radius R of the outlet end of the core model is 25 mm. Using the above formula (2), m = 5.17 is calculated. Taking the absolute value [m] = 5, N 孔 = 13 is calculated, and it can be seen that the number of round holes of the flow guide plate is 13.

[0098] Therefore, for the flow guide plate that can simulate the seepage environment of the reservoir to the greatest extent, the number of round holes is 13 and the aperture of the round holes is 3 mm, as Figure 3 shown. Correspondingly, the aperture of the circular through-hole at the flow guide outlet is also 3 mm, as Figure 9 shown.

[0099] (3) Device module combination and seepage simulation control

[0100] The purpose of this experimental study is to quantitatively reveal the law of formation water carrying sand in the later water breakthrough stage of loose sandstone reservoirs, calculate the critical sand-carrying flow velocity and sand-carrying pressure difference values that cause sand production due to skeleton damage through experiments, and provide a quantitative basis for studying the sand production law of the near-wellbore formation after water breakthrough in the later stage.

[0101] Since the displacement method selected for the critical sand production condition experiment is water flooding, and the movable sand sinks and flows out with the produced fluid, it is necessary to ensure that the movable sand can pass smoothly and is convenient for observation and analysis. Therefore, when selecting the modules of the control device in this embodiment, a filter plate is not selected, and the diversion partition selects an open lower channel, as Figure 8 shown. The assembly sequence of the control device in this embodiment is the flow guide plate, the flow collection channel, the diversion partition, and the flow guide outlet in turn.

[0102] Refer to the water flow velocity sensitivity experiment standard to measure the permeability values of the core at different experimental velocities in turn. At each set velocity point, the simulated formation water with the same standard pore volume multiple is displaced at a constant speed. After the experimental pressure tends to be stable, record the experimental data and calculate the permeability value at this velocity, and use the 0.22 μm filter membrane filtration and weighing method to record the sand production situation under different velocity conditions.

[0103] Experimental temperature: room temperature;

[0104] Experimental fluid: Prepare simulated formation water according to the formation water analysis data of the block to be evaluated;

[0105] Experimental flow velocity: Refer to the water flow velocity sensitivity experiment standard to measure the permeability values of the core at different experimental velocities in turn. The initial velocities lower than the initial experimental velocity of water flow velocity sensitivity (ml / min) are: 0.08, 0.25, 0.5, 0.75, 1, 2, 3, 4, 5, 6.

[0106] Experimental pressure: The pressure value is automatically recorded by the computer.

[0107] After testing, the gas permeability of this natural core is 354 mD, its critical sand-carrying flow rate is 71.97 m / d, the critical sand-carrying pressure difference is 0.422 MPa, the change rate of sand production permeability is 456.87%, the proportion of sand production is 8.87%, and the median size of movable sand particles is 0.1896 mm. The sand production damage degree of this research target is strong, and the sand production situation is as Figure 15 shown.

[0108] When the displacement mode is gas drive, an upper-channel shunt baffle is used; when the displacement mode is the sinking of solids and suspensions, a lower-channel shunt baffle is used.

[0109] This embodiment proves that the control device of the embodiment of the present invention effectively solves the problem that sand particles are blocked inside the existing experimental instruments and the sand production experiment cannot be carried out. The success rate of the experiment is guaranteed and the measurement error is small. The core model outlet end control device based on the embodiment of the present invention can be used to study the sand production seepage and sand-carrying seepage mechanisms of the core, and effectively reveal the influence laws of the main control factors such as the critical sand-carrying pressure difference and flow rate, providing a theoretical and experimental basis for the sand production damage mechanism and laws of unconsolidated sandstone reservoirs in actual production.

[0110] In summary, the core model outlet end control device of the embodiment of the present invention can finely control the output particle size, position, composition and other indicators of the produced fluid, accurately simulate the development seepage environment of different types of oil reservoirs, broaden the research scope and improve the experimental accuracy when designing the development experiment plan, analyze the main control factors affecting the seepage law, and solve the problems of sand production and gas channeling in different development methods such as water drive, gas drive, and chemical drive. It is applicable to the entire life cycle of oil and gas field development in various complex oil reservoirs, especially in the field of oil reservoir seepage characteristics research, with broad application prospects.

[0111] Embodiment 2:

[0112] This embodiment provides a core model outlet end control method, based on the core model outlet end control device described in Embodiment 1, and the method includes:

[0113] Step S1: Calculate the aperture and number of circular holes on the baffle plate based on the physical properties of the reservoir to be studied and using a pre-established particle size control empirical formula to determine the specifications of the baffle plate;

[0114] A baffle plate, which is used to connect the outlet end of the experimental core model. A plurality of circular holes are provided on the baffle plate. The circular hole parameters of the baffle plate are calculated by a pre-established particle size control empirical formula. By controlling the circular hole parameters of the baffle plate, the particle size control of the produced fluid under the simulation experiment conditions of different reservoir seepage characteristics can be realized;

[0115] Step S2: Determine the specifications of the flow splitting partition according to the experimental requirements of different displacement methods. Among them, the flow splitting partition is an upper and lower double-channel flow splitting partition, an upper-channel flow splitting partition, or a lower-channel flow splitting partition;

[0116] Step S3: Determine the specifications of the flow guiding outlet according to the specifications of the flow guiding plate. Among them, there is a circular through-hole at the upper and lower parts of the flow guiding outlet, and the aperture of the circular through-hole is the same as the aperture of the circular hole of the flow guiding plate;

[0117] Step S4: Install the flow guiding plate at the outlet end of the experimental core model, and install the flow collection control module composed of the sequentially connected flow collection channel, flow splitting partition, and flow guiding outlet at the outlet end of the flow guiding plate;

[0118] Step S5: Simulate the development seepage environment of different types of oil reservoirs to carry out different reservoir seepage characteristic simulation experiments to achieve the control of the production particle size, position, and components of the produced fluid.

[0119] Example 3:

[0120] Based on the solutions of the above Example 1 and Example 2, a specific implementation solution is given. This example discloses a control device for the outlet end of a core model and a method for controlling the outlet end of a core model using this device.

[0121] The device includes:

[0122] A flow guiding plate, which is used to connect the outlet end of the experimental core model. A plurality of circular holes are provided on the flow guiding plate, and the circular hole parameters of the flow guiding plate are calculated through a pre-established particle size control empirical formula. By controlling the circular hole parameters of the flow guiding plate, the particle size control of the produced fluid under the simulation experiment conditions of different reservoir seepage characteristics is achieved;

[0123] A flow collection control module, which is connected to the outlet end of the flow guiding plate;

[0124] The flow collection control module includes a sequentially connected flow collection channel, a flow splitting partition, and a flow guiding outlet. The flow collection channel is used to collect the produced fluid flowing out from the outlet end of the flow guiding plate. The flow splitting partition is used to separate the produced fluid flowing out from the flow collection channel so that the separated produced fluid enters different produced fluid outlet channels of the flow guiding outlet respectively.

[0125] According to the analysis of the lithology and pore structure of the target reservoir, comprehensively consider the factors of thermodynamic limit behavior, mechanical shear action, and pore surface ratio, and establish a particle size control empirical formula through the results of a large number of indoor seepage experiments. Then, calculate the circular hole parameters of the flow guiding plate through the particle size control empirical formula, where the circular hole parameters include the aperture and the number of circular holes.

[0126] The circular hole diameter of the flow deflector is calculated by the particle size control empirical formula 1, and the particle size control empirical formula 1 is expressed as:

[0127]

[0128] where d 孔 represents the circular hole diameter of the flow deflector, with the unit of mm; φ represents the deposition particle size; μ represents the main peak mean value; σ represents the main peak variance; d 50 represents the median particle size, with the unit of mm; R represents the radius of the outlet end of the core model, with the unit of mm.

[0129] The number of holes of the flow deflector is calculated by the particle size control empirical formula 2, and the particle size control empirical formula 2 is expressed as:

[0130]

[0131] where N 孔 represents the number of holes; R represents the radius of the outlet end of the core model, with the unit of mm; r 孔 represents the radius of the circular hole, with the unit of mm; m represents the number of layers of the circular hole distribution.

[0132] The circular hole diameter of the flow deflector is 3 mm, and the number of holes of the flow deflector is 13.

[0133] The circular hole diameter of the flow deflector is 6 mm, and the number of holes of the flow deflector is 6.

[0134] The circular hole diameter of the flow deflector is 8 mm, and the number of holes of the flow deflector is 4.

[0135] The flow collecting channel is of a single specification.

[0136] The flow dividing partition has three different specifications to meet the experimental requirements of different displacement modes.

[0137] The flow dividing partition is an upper and lower double-channel flow dividing partition, an upper-channel flow dividing partition or a lower-channel flow dividing partition.

[0138] There is a circular through hole at each of the upper and lower parts of the flow guiding outlet, and the diameter of the circular through hole is the same as the circular hole diameter of the flow deflector.

[0139] The flow collecting control module further includes a filter plate, the filter plate is arranged between the flow collecting channel and the flow dividing partition, and the particle size screening control of the produced fluid is realized by the filter plates with different filter mesh specifications.

[0140] A control method for the outlet end of a core model adopting the above device includes:

[0141] Based on the physical properties of the target reservoir to be studied and using the pre-established empirical formula for particle size control, calculate the aperture diameter and the number of holes of the round holes on the flow guiding plate to determine the specifications of the flow guiding plate;

[0142] Determine the specifications of the flow dividing partition according to the experimental requirements of different displacement methods, wherein the flow dividing partition is an upper and lower double-channel flow dividing partition, an upper-channel flow dividing partition or a lower-channel flow dividing partition;

[0143] Determine the specifications of the flow guiding outlet according to the specifications of the flow guiding plate, wherein there is a circular through hole at each of the upper and lower parts of the flow guiding outlet, and the aperture diameter of the circular through hole is the same as the aperture diameter of the round hole of the flow guiding plate;

[0144] Install the flow guiding plate at the outlet end of the experimental core model, and install the flow collection control module composed of a sequentially connected flow collection channel, a flow dividing partition and a flow guiding outlet at the outlet end of the flow guiding plate;

[0145] Simulate the development seepage environment of different types of oil reservoirs to carry out different reservoir seepage characteristic simulation experiments to achieve the control of the production particle size, position and components of the produced fluid.

[0146] When the displacement method is gas displacement, use the upper-channel flow dividing partition; when the displacement method is the sinking of solids and suspensions, use the lower-channel flow dividing partition.

[0147] Example 4:

[0148] This embodiment provides a core model experimental system, including a core model outlet end control device described in Embodiment 1 above.

[0149] Please note that the technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combinations of these technical features do not conflict, they should be considered as the scope described in this specification. The above embodiments only represent several implementation manners of the present application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several deformations and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

[0150] The above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

[0151] Although some specific embodiments of the present invention have been described in detail by way of examples, those skilled in the art should understand that the above examples are only for illustration purposes and not for limiting the scope of the present invention. Those skilled in the art should understand that the above embodiments can be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A control device for the outlet end of a core model, characterized in that The device includes: A deflector plate, which is used to connect the outlet end of the experimental core model. A plurality of round holes are provided on the deflector plate. The round hole parameters of the deflector plate are calculated by a pre-established particle size control empirical formula. By controlling the round hole parameters of the deflector plate, the particle size control of the produced fluid under the simulation experiment conditions of different reservoir seepage characteristics is realized; A flow collection control module, which is connected to the outlet end of the deflector plate; The flow collection control module includes a flow collection channel, a flow splitting partition plate and a flow guiding outlet connected in sequence. The flow collection channel is used to collect the produced fluid flowing out from the outlet end of the deflector plate. The flow splitting partition plate is used to separate the produced fluid flowing out from the flow collection channel, so that the separated produced fluid enters different produced fluid outlet channels of the flow guiding outlet respectively.

2. The control device for the outlet end of a core model according to claim 1, characterized in that According to the lithology and pore structure analysis of the target reservoir, comprehensively considering the factors of thermodynamic limit behavior, mechanical shear action and pore surface ratio, and establishing a particle size control empirical formula through a large number of indoor seepage experiment results. Then, the round hole parameters of the deflector plate are calculated by the particle size control empirical formula, where the round hole parameters include the round hole diameter and the number of holes.

3. The control device for the outlet end of a core model according to claim 2, characterized in that The round hole diameter of the deflector plate is calculated by the particle size control empirical formula 1, and the particle size control empirical formula 1 is expressed as: Among them, d 孔 represents the aperture diameter of the round hole of the deflector, with the unit of mm; φ represents the sedimentation grain size; μ represents the main peak mean value; σ represents the main peak variance; d 50 represents the median grain size, with the unit of mm; R represents the radius of the outlet end of the core model, with the unit of mm.

4. The control device for the outlet end of a core model according to claim 3, characterized in that The number of holes of the deflector plate is calculated by the particle size control empirical formula 2, and the particle size control empirical formula 2 is expressed as: Among them, N 孔 represents the number of holes; R represents the radius of the outlet end of the core model, in mm; r 孔 represents the radius of the circular hole, in mm; m represents the number of layers of circular hole distribution.

5. The control device for the outlet end of a core model according to claim 2, characterized in that The round hole diameter of the deflector plate is 3 mm, and the number of holes of the deflector plate is 13.

6. The control device for the outlet end of a core model according to claim 2, characterized in that The round hole diameter of the deflector plate is 6 mm, and the number of holes of the deflector plate is 6.

7. The control device for the outlet end of a core model according to claim 2, characterized in that The round hole diameter of the deflector plate is 8 mm, and the number of holes of the deflector plate is 4.

8. The control device for the outlet end of a core model according to claim 1, characterized in that The flow collection channel is of a single specification.

9. The control device for the outlet end of a core model according to claim 1, characterized in that The flow splitting partition plate has three different specifications to meet the experimental requirements of different displacement modes.

10. The control device for the outlet end of a core model according to claim 9, characterized in that The flow splitting partition plate is an upper and lower double-channel flow splitting partition plate, an upper-channel flow splitting partition plate or a lower-channel flow splitting partition plate.

11. The control device for the outlet end of a core model according to claim 10, characterized in that There is a circular through hole at the upper and lower parts of the flow guiding outlet, and the aperture of the circular through hole is the same as the round hole diameter of the deflector plate.

12. The control device for the outlet end of a core model according to any one of claims 1-11, characterized in that The flow collection control module further includes a filter plate, which is arranged between the flow collection channel and the flow splitting partition plate. The particle size screening control of the produced fluid is realized by the filter plates with different filter mesh specifications.

13. A control method for the outlet end of a core model, characterized in that The method includes: Based on the physical properties of the target reservoir to be studied and using the pre-established particle size control empirical formula, calculate the round hole diameter and the number of holes on the deflector plate to determine the specification of the deflector plate; Determine the specification of the flow splitting partition plate according to the experimental requirements of different displacement modes, where the flow splitting partition plate is an upper and lower double-channel flow splitting partition plate, an upper-channel flow splitting partition plate or a lower-channel flow splitting partition plate; Determine the specification of the flow guiding outlet according to the specification of the deflector plate, where there is a circular through hole at the upper and lower parts of the flow guiding outlet, and the aperture of the circular through hole is the same as the round hole diameter of the deflector plate; Install the deflector plate at the outlet end of the experimental core model, and install the flow collection control module composed of the flow collection channel, the flow splitting partition plate and the flow guiding outlet connected in sequence at the outlet end of the deflector plate; Simulate the development seepage environment of different types of oil reservoirs and conduct simulation experiments on the seepage characteristics of different reservoirs to achieve control over the production particle size, position, and components of the produced fluid.

14. The core model outlet end control method according to claim 13, characterized in that When the displacement method is gas drive, an upper channel shunt baffle is used; when the displacement method is the sinking of solids and suspensions, a lower channel shunt baffle is used.

15. A core model experiment system, characterized in that It includes a core model outlet end control device according to any one of claims 1 to 12.

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