Thin heavy oil reservoir superheated steam flooding physical simulation experiment device and method

Abstract

The invention provides a physical simulation experiment device and method for superheated steam flooding of a thin-layer heavy oil reservoir. The physical simulation experiment device for superheated steam flooding of the thin-layer heavy oil reservoir comprises a superheated steam generator, a superheated steam displacement simulation device, an output liquid collection device and a data acquisition device. The superheated steam displacement simulation device comprises temperature sensors which are uniformly arranged at equal intervals, and data of the temperature sensors are collected by a data acquisition device. The whole process of superheated steam flooding of the horizontal well row-shaped well pattern of the thin heavy oil reservoir can be well simulated, the temperature field change condition can be drawn in real time by using the temperature sensor, the two-dimensional steam cavity development, the temperature field change and the yield dynamic process of superheated steam flooding of the horizontal well row-shaped well pattern can be simulated, and the test result is accurate. And the simulation structure and the field actual production process have very high shape similarity.

Description

Technical Field

[0001] The invention belongs to the technical field of heavy oil extraction, and relates to a physical simulation experimental device and method for steam flooding of heavy oil, in particular to a physical simulation experimental device and method for superheated steam flooding of thin-layer heavy oil reservoirs. Background Art

[0002] Superheated steam is a special state of water. Similar to conventional steam injection oil recovery, it is used as a heat carrier in the heavy oil recovery process. The special nature of superheated steam means its oil recovery mechanism shares similarities with conventional steam injection oil recovery, while also possessing its own unique characteristics. The main mechanisms of superheated steam are as follows:

[0003] (1) High-temperature viscosity reduction. The viscosity of heavy oil is very sensitive to temperature changes. High-temperature viscosity reduction greatly reduces the original seepage resistance. Steam injection increases the reservoir temperature, significantly reduces the viscosity of oil and water, and improves the water-oil mobility ratio.

[0004] (2) Steam distillation: Superheated steam can significantly increase the steam distillation rate of heavy oil, increasing the content of heavy hydrocarbons in the distillate, which plays an important role in the development of ultra-heavy oil reservoirs;

[0005] (3) Thermal expansion, especially in the first cycle of huff-and-puff, plays a very important role, which can recover 5-10% of the crude oil reserves, and its size mainly depends on the type of crude oil, the initial oil saturation of the reservoir and the heating temperature;

[0006] (4) Aquathermolysis: Aquathermolysis can change the content of the four components in heavy oil, permanently reduce the viscosity of heavy oil, and also reduce the content of heteroatoms such as sulfur, oxygen, and nitrogen, thereby improving the quality of crude oil;

[0007] (5) Blockage removal: The high-temperature flushing effect of injected steam on the rock can effectively remove the pollution of drilling fluid near the wellbore. When the well is opened for production, oil, steam, and condensate can flow into the wellbore at high speed, carrying the blockage into the wellbore, thereby improving the seepage conditions near the wellbore;

[0008] (6) Emulsion flooding: Heavy oil contains a certain amount of natural emulsified rubber, including asphalt, colloid, cyclohexane acid, soap, etc. These substances may condense at the steam front under the action of high-temperature distillation to form water-in-oil emulsion; they may also emulsify the condensate water into the crude oil to form oil-in-water emulsion; this increases the driving pressure. This viscous emulsion will reduce the fingering of steam, improve the sweep condition, and is conducive to steam flooding production.

[0009] Understanding and mastering the superheated steam flooding mechanism of heavy oil reservoirs through indoor physical experiments is very important for improving heavy oil recovery results.

[0010] CN103032057A discloses a three-dimensional physical simulation system for steam flooding of heavy oil horizontal wells. Its temperature sensors are arranged in three layers: upper, middle, and lower. They can measure the temperature distribution within the experimental oil layer in the vertical direction. However, this device is suitable for simulating the steam flooding development process of thick and very thick heavy oil reservoirs, and it is difficult to simulate the superheated steam flooding process of thin heavy oil reservoirs.

[0011] CN202273662U discloses a superheated steam generator and an oil displacement physical simulation experimental device having the same. The device can generate superheated steam and simulate the steam displacement process by injecting the superheated steam into a core tube. However, actual oil displacement reservoirs cannot be simulated using a one-dimensional experimental device, and the device cannot simulate the horizontal well network displacement development of thin-layer heavy oil reservoirs. CN103375155A discloses a linear physical simulation system for thermal recovery of heavy oil reservoirs. The system simulates the steam displacement process by injecting constant flow rate steam into a single-tube model. However, actual oil displacement reservoirs cannot be simulated using a one-dimensional experimental device. The oil layer thickness of such reservoirs is relatively thin in the vertical direction and has a certain distribution in the plane. Therefore, a two-dimensional experimental device is required for simulation.

[0012] CN104405356A discloses a two-dimensional physical simulation device for steam flooding of horizontal wells in thin-layer heavy oil reservoirs. The device can simulate the steam flooding process, but the temperature and pressure tolerance of the experimental device make it impossible to simulate superheated steam flooding. In addition, the steam injection wells and oil production wells of the device are on both sides of the device, which cannot well simulate the actual steam injection conditions in the formation.

[0013] Therefore, it is necessary to provide a simulation experimental device and method suitable for thin-layer heavy oil reservoirs and superheated steam flooding. Summary of the Invention

[0014] The purpose of the present invention is to provide a physical simulation experimental device and method for superheated steam flooding in thin-layer heavy oil reservoirs. The physical simulation experimental device for superheated steam flooding in thin-layer heavy oil reservoirs can well simulate the entire process of superheated steam flooding in a horizontal well pattern in a thin-layer heavy oil reservoir, and can draw temperature field changes in real time. It can also simulate the two-dimensional steam cavity development, temperature field changes and production dynamic process of superheated steam flooding in the horizontal well pattern, so that the simulated structure has a high degree of similarity with the actual production process on site.

[0015] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0016] In a first aspect, the present invention provides a physical simulation experimental device for superheated steam flooding in a thin-layer heavy oil reservoir, the physical simulation experimental device for superheated steam flooding in a thin-layer heavy oil reservoir comprising a superheated steam generator, a superheated steam displacement simulation device, a produced fluid collection device, and a data acquisition device;

[0017] The superheated steam displacement simulation device includes an upper shell and a lower shell; the space enclosed by the upper shell and the lower shell is filled with glass sand to simulate an underground sandstone reservoir;

[0018] The first horizontal well and the second horizontal well are buried in the simulated oil layer to simulate the facing well network of the actual oil field;

[0019] A steam injection port is provided on one side of the first horizontal well, and a liquid discharge port is provided on a side of the second horizontal well away from the steam injection port; the steam injection port is connected to the gas outlet of the superheated steam generator; and the liquid discharge port is connected to the liquid outlet of the produced liquid collection device;

[0020] The inner wall of the upper shell is pasted with a heat-insulating silica gel layer;

[0021] The inner wall of the lower shell is pasted with a heat-insulating silica gel layer;

[0022] The superheated steam displacement simulation device further includes temperature sensors arranged evenly and at equal intervals, and data from the temperature sensors are collected by a data acquisition device.

[0023] The physical simulation experimental device for superheated steam flooding in thin-layer heavy oil reservoirs provided by the present invention can effectively simulate the entire process of superheated steam flooding in a horizontal well pattern in a thin-layer heavy oil reservoir. Through the use of temperature sensors, it can map temperature field changes in real time and simulate the two-dimensional steam cavity development, temperature field changes, and production dynamics of superheated steam flooding in a horizontal well pattern, ensuring a high degree of similarity between the simulated structure and the actual production process. Furthermore, the present invention adheres a thermal insulation silicone layer to the inner walls of the upper and lower shells, respectively, reducing the impact of wall heat loss on the experimental results.

[0024] When using the thin-layer heavy oil reservoir superheated steam drive physical simulation experimental device provided by the present invention, glass sand is filled in the space enclosed by the upper shell and the lower shell to simulate the underground sandstone reservoir; the heavy oil sample and the formation saturation model are used to simulate the actual oil reservoir; at least two horizontal wells are buried in the simulated oil layer to simulate the facing wells in the actual oil field; the inner wall of the upper shell and the inner wall of the lower shell are respectively adhered with a heat-insulating silica gel layer with good thermal insulation performance; the outside of the entire device is wrapped with a heating layer and a heat-insulating layer to further reduce the influence of wall heat loss on the experimental results; the temperature sensor is connected to a data acquisition device to display the temperature field in the device changing over time.

[0025] Exemplarily, the height of the first horizontal well is lower than that of the second horizontal well to facilitate the superheated steam drive process; preferably, the steam injection port of the first horizontal well is provided in the lower shell, and the liquid discharge port of the second horizontal well is provided with an upper shell.

[0026] Preferably, the upper shell has a pressure resistance of ≥1.5 MPa.

[0027] Preferably, the upper shell has a temperature resistance of ≥180°C.

[0028] Preferably, the lower shell has a pressure resistance of ≥1.5 MPa.

[0029] Preferably, the lower shell has a temperature resistance of ≥180°C.

[0030] Preferably, the space enclosed by the upper shell and the lower shell is a rectangular parallelepiped.

[0031] The steam injection port and the liquid discharge port are respectively arranged on the plane formed by the width and height of the rectangular parallelepiped.

[0032] Preferably, the length of the cuboid is 580-620 mm, the width is 180-220 mm, and the height is 40-60 mm.

[0033] Preferably, the simulated well spacing in the superheated steam displacement simulation device is 160-200 mm.

[0034] Preferably, the distance between adjacent temperature sensors is 45-55 mm.

[0035] Preferably, the distance between the edge temperature sensor and the wall surface is 20-30 mm.

[0036] Preferably, the temperature sensors in the superheated steam displacement simulation device are arranged in an array.

[0037] Preferably, the temperature sensors are arranged in 3-5 rows along the width direction of the superheated steam displacement simulation device.

[0038] Preferably, the temperature sensors are arranged in 11-13 rows along the length direction of the superheated steam displacement simulation device.

[0039] In a second aspect, the present invention provides a method for physical simulation of superheated steam flooding in thin-layer heavy oil reservoirs. The method is performed in the physical simulation experimental device for superheated steam flooding in thin-layer heavy oil reservoirs described in the first aspect.

[0040] Preferably, the method comprises the following steps: superheated steam enters the superheated steam displacement simulation device from the steam injection port, and temperature field changes are mapped in real time using a temperature sensor.

[0041] Preferably, the temperature of the superheated steam is 175-185°C.

[0042] Preferably, the injection rate of the superheated steam is 1.5-2.5 mL / min.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] The physical simulation experimental device for superheated steam flooding in thin-layer heavy oil reservoirs provided by the present invention can effectively simulate the entire process of superheated steam flooding in a horizontal well pattern in a thin-layer heavy oil reservoir. Through the use of temperature sensors, it can map temperature field changes in real time and simulate the two-dimensional steam cavity development, temperature field changes, and production dynamics of superheated steam flooding in a horizontal well pattern, ensuring a high degree of similarity between the simulated structure and the actual production process. Furthermore, the present invention adheres a thermal insulation silicone layer to the inner walls of the upper and lower shells, respectively, reducing the impact of wall heat loss on the experimental results. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 A schematic structural diagram of a thin-layer heavy oil superheated steam physical simulation experimental device provided by the present invention;

[0046] Figure 2 Schematic diagram of the structure of the superheated steam displacement simulation device in Example 1;

[0047] Figure 3 Schematic diagram of the temperature sensor distribution of the superheated steam displacement simulation device in Example 1;

[0048] Figure 4(a) to Figure 4(h) Provide the superheated steam flooding temperature field at different times for Example 1;

[0049] Figure 5 A graph showing the change in liquid and oil production rates over time in the method provided in Example 1;

[0050] Figure 6 A graph showing changes in pump pressure over time in the method provided in Example 1;

[0051] Figure 7 A graph showing the variation of the superheated steam flooding recovery rate over time in the method provided in Example 1;

[0052] Figure 8 The present invention provides a curve chart of the change of water content in superheated steam drive over time in the method of Example 1.

[0053] Among them: 1, upper shell; 2, lower shell; 3, flange; 4, temperature sensor; 5, superheated steam generator; 6, produced fluid collection device; 7, data acquisition device; 8, first horizontal well; 9, second horizontal well. DETAILED DESCRIPTION

[0054] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0055] A certain embodiment of the present invention provides a physical simulation experimental device for superheated steam flooding in a thin-layer heavy oil reservoir, the physical simulation experimental device for superheated steam flooding in a thin-layer heavy oil reservoir comprising a superheated steam generator, a superheated steam displacement simulation device, a produced fluid collection device, and a data acquisition device;

[0056] The superheated steam displacement simulation device includes an upper shell and a lower shell; the space enclosed by the upper shell and the lower shell is filled with glass sand to simulate an underground sandstone reservoir;

[0057] The first horizontal well and the second horizontal well are buried in the simulated oil layer to simulate the facing well network of the actual oil field;

[0058] A steam injection port is provided on one side of the first horizontal well, and a liquid discharge port is provided on a side of the second horizontal well away from the steam injection port; the steam injection port is connected to the gas outlet of the superheated steam generator; and the liquid discharge port is connected to the liquid outlet of the produced liquid collection device;

[0059] The inner wall of the upper shell is pasted with a heat-insulating silica gel layer;

[0060] The inner wall of the lower shell is pasted with a heat-insulating silica gel layer;

[0061] The superheated steam displacement simulation device further includes temperature sensors arranged evenly and at equal intervals, and data from the temperature sensors are collected by a data acquisition device.

[0062] The physical simulation experimental device for superheated steam flooding in thin-layer heavy oil reservoirs provided by the present invention can effectively simulate the entire process of superheated steam flooding in a horizontal well pattern in a thin-layer heavy oil reservoir. Through the use of temperature sensors, it can map temperature field changes in real time and simulate the two-dimensional steam cavity development, temperature field changes, and production dynamics of superheated steam flooding in a horizontal well pattern, ensuring a high degree of similarity between the simulated structure and the actual production process. Furthermore, the present invention adheres a thermal insulation silicone layer to the inner walls of the upper and lower shells, respectively, reducing the impact of wall heat loss on the experimental results.

[0063] When using the thin-layer heavy oil reservoir superheated steam drive physical simulation experimental device provided by the present invention, glass sand is filled in the space enclosed by the upper shell and the lower shell to simulate the underground sandstone reservoir; the heavy oil sample and the formation saturation model are used to simulate the actual oil reservoir; at least two horizontal wells are buried in the simulated oil layer to simulate the facing wells in the actual oil field; the inner wall of the upper shell and the inner wall of the lower shell are respectively adhered with a heat-insulating silica gel layer with good thermal insulation performance; the outside of the entire device is wrapped with a heating layer and a heat-insulating layer to further reduce the influence of wall heat loss on the experimental results; the temperature sensor is connected to a data acquisition device to display the temperature field in the device changing over time.

[0064] Exemplarily, the height of the first horizontal well is lower than that of the second horizontal well to facilitate the superheated steam drive process; in some embodiments, the steam injection port of the first horizontal well is provided in the lower shell, and the liquid discharge port of the second horizontal well is provided with an upper shell.

[0065] In some embodiments, the particle size of the glass sand is 100-150 mesh, for example, it can be 100 mesh, 120 mesh, 140 mesh or 150 mesh, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0066] The present invention does not further limit the specific model of the superheated steam generator, as long as it can generate superheated steam that meets the process requirements.

[0067] The present invention does not further limit the specific model of the data acquisition device, as long as it can acquire the data signal of the temperature sensor.

[0068] In some embodiments, the upper shell has a pressure resistance of ≥1.5 MPa, for example, it can be 1.5 MPa, 1.8 MPa, 2 MPa, 2.4 MPa or 2.5 MPa, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0069] In some embodiments, the upper shell has a temperature resistance of ≥180°C, for example, it can be 180°C, 200°C, 300°C, 400°C, 500°C, 600°C, 800°C or 1000°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0070] Exemplarily, the upper shell is made of Hastelloy C276.

[0071] In some embodiments, the pressure resistance of the lower shell is ≥1.5 MPa, for example, it can be 1.5 MPa, 1.8 MPa, 2 MPa, 2.4 MPa or 2.5 MPa, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0072] In some embodiments, the lower shell has a temperature resistance of ≥180°C, for example, it can be 180°C, 200°C, 300°C, 400°C, 500°C, 600°C, 800°C or 1000°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0073] Exemplarily, the upper shell is made of Hastelloy C276.

[0074] In some embodiments, the space enclosed by the upper shell and the lower shell is a cuboid.

[0075] The steam injection port and the liquid discharge port are respectively arranged on the plane formed by the width and height of the rectangular parallelepiped.

[0076] In some embodiments, the connection method between the upper shell and the lower shell includes flange connection.

[0077] In some embodiments, the cuboid has a length of 580-620 mm, a width of 180-220 mm, and a height of 40-60 mm.

[0078] The length of the cuboid is 580-620 mm, for example, 580 mm, 590 mm, 600 mm, 610 mm or 620 mm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0079] The width of the cuboid is 180-220 mm, for example, 180 mm, 190 mm, 200 mm, 210 mm or 220 mm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0080] The height of the cuboid is 40-60 mm, for example, 40 mm, 45 mm, 50 mm, 55 mm or 60 mm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0081] In some embodiments, the simulated well spacing in the superheated steam displacement simulation device is 160-200 mm, for example, it can be 160 mm, 170 mm, 180 mm, 190 mm or 200 mm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0082] In some embodiments, the distance between adjacent temperature sensors is 45-55 mm, for example, 45 mm, 48 mm, 50 mm, 54 mm, or 55 mm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0083] In some embodiments, the distance between the edge temperature sensor and the wall is 20-30 mm, for example, 20 mm, 22 mm, 24 mm, 25 mm, 28 mm or 30 mm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0084] In certain embodiments, the temperature sensors in the superheated steam displacement simulation device are arranged in an array.

[0085] In some embodiments, the temperature sensors are arranged in 3-5 rows along the width direction of the superheated steam displacement simulation device, for example, 3 rows, 4 rows, or 5 rows.

[0086] In some embodiments, the temperature sensors are arranged in 11-13 rows along the length direction of the superheated steam displacement simulation device, for example, in 11 rows, 12 rows, or 13 rows.

[0087] In some embodiments, a heat-insulating silicone layer is adhered to the inner wall of the upper shell.

[0088] In some embodiments, a heat-insulating silicone layer is adhered to the inner wall of the lower shell.

[0089] A certain embodiment of the present invention provides a method for physical simulation of superheated steam flooding in a thin-layer heavy oil reservoir. The method is performed in the physical simulation experimental device for superheated steam flooding in a thin-layer heavy oil reservoir described in certain embodiments.

[0090] In certain embodiments, the method includes the following steps: superheated steam enters the superheated steam displacement simulation device through a steam injection port, and temperature field changes are mapped in real time using a temperature sensor.

[0091] In some embodiments, the temperature of the superheated steam is 175-185°C, for example, 175°C, 178°C, 180°C, 182°C or 185°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0092] In some embodiments, the injection rate of the superheated steam is 1.5-2.5 mL / min, for example, it can be 1.5 mL / min, 1.8 mL / min, 2 mL / min, 2.4 mL / min or 2.5 mL / min, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0093] Exemplarily, the method for physical simulation of superheated steam flooding in a thin-layer heavy oil reservoir provided by the present invention comprises the following steps:

[0094] (1) Clean the inner walls of the upper and lower shells to ensure that they are clean and dry;

[0095] (2) a heat-insulating silicone layer is attached to the inner wall of the upper shell, and a heat-insulating silicone layer is attached to the inner wall of the lower shell;

[0096] (3) A fixed simulated horizontal well is installed in the space enclosed by the upper shell and the lower shell, and then filled with glass sand in accordance with the simulated formation conditions; after filling, the glass sand is tightly fitted to the thermal insulation silica gel layer;

[0097] (4) Seal the space enclosed by the upper shell and the lower shell to ensure that the model has good sealing performance;

[0098] (5) After the saturated simulated oil is completed, wait for the model temperature to stabilize at the oil layer temperature, and then start steam displacement: turn on the superheated steam generator to inject superheated steam into the mold at the set steam injection rate. When the temperature field and flow rate no longer change, the steam displacement process ends; record the temperature field, liquid production, oil production, and residual oil during the steam displacement process.

[0099] Exemplarily, the simulation of heavy oil in step (5) refers to injecting heavy oil into the model, and adjusting and flipping the model multiple times during the injection period to fully saturate the heavy oil to simulate the actual reservoir environment until oil is uniformly discharged from the outlet.

[0100] Example 1

[0101] This embodiment provides a Figure 1 The thin-layer heavy oil reservoir superheated steam flooding physical simulation experimental device shown in the figure comprises a superheated steam generator 5, a superheated steam displacement simulation device, a production fluid collection device 6 and a data acquisition device 7;

[0102] The structural diagram of the superheated steam displacement simulation device is as follows: Figure 2 As shown, it includes an upper shell 1 and a lower shell 2, and the upper shell 1 and the lower shell 2 are connected by a flange 3; the space enclosed by the upper shell 1 and the lower shell 2 is filled with glass sand with a particle size of 120 mesh;

[0103] The first horizontal well 8 and the second horizontal well 9 are buried in the simulated oil layer to simulate the facing well network of an actual oil field; a steam injection port is provided on one side of the first horizontal well 8, and a liquid discharge port is provided on the side of the second horizontal well 9 away from the steam injection port;

[0104] The inner wall of the upper shell 1 is pasted with a heat-insulating silicone layer; the inner wall of the lower shell 2 is pasted with a heat-insulating silicone layer;

[0105] The space enclosed by the upper shell 1 and the lower shell 2 is a rectangular parallelepiped, and the steam injection port and the liquid discharge port are respectively arranged on the plane formed by the width and height of the rectangular parallelepiped; the length of the rectangular parallelepiped is 600 mm, the width is 200 mm, and the height is 50 mm;

[0106] The simulated well spacing between the first horizontal well 8 and the second horizontal well 9 in the superheated steam displacement simulation device is 180 mm;

[0107] A steam injection port is provided on one side of the lower shell 2; a liquid discharge port is provided on a side of the upper shell 1 away from the steam injection port; the steam injection port is connected to the gas outlet of the superheated steam generator 5; the liquid discharge port is connected to the liquid outlet of the produced liquid collecting device 6;

[0108] The superheated steam displacement simulation device further includes temperature sensors 4 arranged evenly and at equal intervals, and data from the temperature sensors 4 are collected by a data acquisition device 7;

[0109] The distribution diagram of the temperature sensor 4 in the superheated steam displacement simulation device is as follows: Figure 3 As shown, the temperature sensors 4 are arranged in 4 rows along the width direction of the superheated steam displacement simulation device; the temperature sensors 4 are arranged in 12 columns along the length direction of the superheated steam displacement simulation device; the distance between adjacent temperature sensors 4 is 50 mm, and the distance between the edge temperature sensors 4 and the wall surface is 25 mm;

[0110] The method for simulating in the physical simulation experimental device for superheated steam flooding of thin-layer heavy oil reservoirs provided in this embodiment comprises the following steps:

[0111] (1) Clean the inner walls of the upper shell 1 and the lower shell 2 to ensure that the upper shell 1 and the lower shell 2 are clean and dry;

[0112] (2) A heat-insulating silicone layer is attached to the inner wall of the upper shell 1 and a heat-insulating silicone layer is attached to the inner wall of the lower shell 2;

[0113] (3) A fixed simulated horizontal well is installed in the space enclosed by the upper shell 1 and the lower shell 2, and then filled with 120-mesh glass sand in accordance with the simulated formation conditions; after filling, the glass sand is tightly attached to the thermal insulation silica gel layer;

[0114] (4) Use flange 3 to connect the space enclosed by the upper shell 1 and the lower shell 2 to ensure that the model has good sealing performance;

[0115] (5) After the saturation of the simulated oil is completed, wait for the model temperature to stabilize at the oil layer temperature, and then start steam displacement: turn on the superheated steam generator 5 to provide superheated steam with a temperature of 180 ° C, and then inject the superheated steam into the mold at a steam injection rate of 2 mL / min. The temperature field changes at different stages are shown in the figure below. Figure 4(a)-Figure 4(h) As shown; when the temperature field and flow rate no longer change, the steam displacement process ends; the temperature field, liquid production, oil production and remaining oil during the steam displacement process are recorded.

[0116] From the recorded data, we can see that the curves of liquid and oil production rates changing with time are as follows: Figure 5 As shown;

[0117] The curve of pump pressure changing with time is as follows Figure 6 As shown;

[0118] The curve of superheated steam flooding recovery rate changing with time is shown in the figure below: Figure 7 As shown;

[0119] The curve of water content in superheated steam flooding changing with time is shown in the figure below: Figure 8shown.

[0120] Depend on Figure 4(a)-Figure 4(h) As can be seen, under homogeneous formation conditions, the overall uneven distribution of steam along the horizontal well is relatively low. The steam region at the injection port foot and the injection port toe develops in nearly identical patterns, with the injection port toe exhibiting a slightly downward slope. This phenomenon may be due to the higher temperature and greater steam sweep velocity of the heated steam, allowing it to spread from the first horizontal well to the second in a shorter period of time. The steam region develops rapidly in the early stages and slowly in the later stages. In the late stages of the experiment, the steam region nearly covers the entire simulated formation, demonstrating a highly efficient sweep.

[0121] Depend on Figure 5 and Figure 6 It can be seen that the relationship between the oil production rate and the liquid production rate of superheated steam drive over time tends to be consistent, and the shape of the pump pressure over time is similar. Initially, the production rate is almost zero, corresponding to the temperature field with less developed steam chambers. At this time, the steam sweep range in the simulated reservoir is small. There are peaks in the oil and liquid production rates in the early stage. At this time, the pump pressure is maximum, corresponding to the temperature field with faster steam chamber development. The rate then decreases. On the one hand, the oil in the macropores has been produced. On the other hand, heat loss affects the gas drive effect. In the early stage, the liquid production rate is almost equal to the oil production rate. On the other hand, the liquid production rate tends to be constant in the later stage, and the oil production rate is close to zero. This indicates that the recoverable oil has been produced in the later stage, while water production increases. This is caused by the gradual condensation of the injected steam into water.

[0122] Although the steam temperature field is almost completely affected in the later stage of displacement, the liquid and oil production rates decrease. Firstly, the increase in the steam coverage leads to increased heat loss, steam condensation, and reduced oil displacement energy; secondly, the steam injected in the later stage has formed a steam channel in the simulated oil reservoir, and some residual oil cannot be used; thirdly, a lot of recoverable oil has been produced.

[0123] Depend on Figure 7 、 Figure 8 It can be seen that the water cut during superheated steam flooding continues to rise. The water cut increases rapidly in the early stages, then slowly in the later stages, ultimately reaching 90%, indicating that the recoverable oil has been produced. The recovery rate approaches zero in the first 100 minutes of superheated steam flooding, indicating that the injected steam has not yet taken effect. The relatively small amount of steam injected over such a short period of time prevents sufficient diffusion and heating of the simulated reservoir. The increase in recovery rate in the early stages, i.e., the slope of the curve, is greater than in the later stages, indicating higher oil production in the early stages, corresponding to the rapidly developing temperature field of the steam chamber. The later stages produce relatively less oil than in the early stages, corresponding to the slower development of the temperature field.

[0124] In summary, the physical simulation experimental device for superheated steam flooding in thin-layer heavy oil reservoirs provided by the present invention can well simulate the entire process of superheated steam flooding in horizontal well patterns in thin-layer heavy oil reservoirs. By using temperature sensors, the temperature field changes can be mapped in real time, and the two-dimensional steam cavity development, temperature field changes and production dynamics of superheated steam flooding in horizontal well patterns can be simulated, so that the simulated structure has a high degree of similarity to the actual production process on site.

[0125] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the protection scope and disclosure scope of the present invention.

Claims

1. A physical simulation experimental device for superheated steam flooding in thin-layer heavy oil reservoirs, characterized in that: The thin-layer heavy oil reservoir superheated steam flooding physical simulation experimental device includes a superheated steam generator, a superheated steam displacement simulation device, a production fluid collection device and a data acquisition device; The superheated steam displacement simulation device includes an upper shell and a lower shell; the space enclosed by the upper shell and the lower shell is filled with glass sand to simulate an underground sandstone reservoir; The first horizontal well and the second horizontal well are buried in the simulated oil layer to simulate the facing well network of the actual oil field; A steam injection port is provided on one side of the first horizontal well, and a liquid discharge port is provided on a side of the second horizontal well away from the steam injection port; the steam injection port is connected to the gas outlet of the superheated steam generator; and the liquid discharge port is connected to the liquid outlet of the produced liquid collection device; The inner wall of the upper shell is pasted with a heat-insulating silica gel layer; The inner wall of the lower shell is pasted with a heat-insulating silica gel layer; The superheated steam displacement simulation device further includes temperature sensors arranged evenly and at equal intervals, and data from the temperature sensors are collected by a data acquisition device.

2. The physical simulation experimental device for superheated steam flooding of thin-layer heavy oil reservoirs according to claim 1 is characterized in that: The upper shell has a pressure resistance of ≥1.5MPa; Preferably, the upper shell has a temperature resistance of ≥180°C.

3. The physical simulation experimental device for superheated steam flooding of thin-layer heavy oil reservoirs according to claim 1 or 2, characterized in that: The lower shell has a pressure resistance of ≥1.5MPa; Preferably, the lower shell has a temperature resistance of ≥180°C.

4. The physical simulation experimental device for superheated steam flooding of thin-layer heavy oil reservoirs according to any one of claims 1 to 3, characterized in that: The space enclosed by the upper shell and the lower shell is a cuboid; The steam injection port and the liquid discharge port are respectively arranged on the plane formed by the width and height of the rectangular parallelepiped.

5. The physical simulation experimental device for superheated steam flooding of thin-layer heavy oil reservoirs according to claim 4 is characterized in that: The length of the rectangular parallelepiped is 580-620 mm, the width is 180-220 mm, and the height is 40-60 mm; Preferably, the simulated well spacing in the superheated steam displacement simulation device is 160-200 mm.

6. The physical simulation experimental device for superheated steam flooding of thin-layer heavy oil reservoirs according to any one of claims 1 to 5, characterized in that: The distance between adjacent temperature sensors is 45-55mm; Preferably, the distance between the edge temperature sensor and the wall surface is 20-30 mm.

7. The physical simulation experimental device for superheated steam flooding of thin-layer heavy oil reservoirs according to any one of claims 1 to 6, characterized in that: The temperature sensors in the superheated steam displacement simulation device are arranged in an array.

8. The physical simulation experimental device for superheated steam flooding of thin-layer heavy oil reservoirs according to claim 7 is characterized in that: The temperature sensors are arranged in 3-5 rows along the width direction of the superheated steam displacement simulation device; Preferably, the temperature sensors are arranged in 11-13 rows along the length direction of the superheated steam displacement simulation device.

9. A method for physical simulation of superheated steam flooding in thin-layer heavy oil reservoirs, characterized in that: The method is carried out in the physical simulation experimental device for superheated steam flooding of thin-layer heavy oil reservoirs according to any one of claims 1 to 8.

10. The method according to claim 8, characterized in that The method comprises the following steps: superheated steam enters the superheated steam displacement simulation device from the steam injection port, and uses a temperature sensor to draw a temperature field change in real time; Preferably, the temperature of the superheated steam is 175-185°C; Preferably, the injection rate of the superheated steam is 1.5-2.5 mL / min.

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