Dual-overpressure bidirectional hydrocarbon expulsion simulation device and simulation method thereof

Abstract

The invention relates to a double-overpressure bidirectional hydrocarbon expulsion simulation device and a simulation method thereof.The double-overpressure bidirectional hydrocarbon expulsion simulation device comprises a hydrocarbon expulsion model subsystem, a water phase supercharging device, an oil phase supercharging device and a monitoring and collecting subsystem, and a hydrocarbon expulsion model of the hydrocarbon expulsion model subsystem is immersed in a water tank; the hydrocarbon expulsion model is a two-dimensional visual filling model, a mudstone area, an upper reservoir, a hydrocarbon source rock layer and a lower reservoir are clamped between the two glass plates, the hydrocarbon source rock layer is divided into an upper layer section and a lower layer section of the hydrocarbon source rock by the hydrocarbon source rock hypertonic zone, and the position of the hydrocarbon source rock hypertonic zone in the hydrocarbon source rock layer is determined according to the position of the actual stratum main hydrocarbon source rock layer; the bottom of a water phase pressurization water storage container of the water phase pressurization device is connected with a hydrocarbon source rock high-permeability zone, oil on the upper portion of a transparent middle container of the oil phase pressurization device is connected with the hydrocarbon source rock high-permeability zone through a pipeline, and the oil or water enters an upper layer section and a lower layer section of the hydrocarbon source rock through the hydrocarbon source rock high-permeability zone in a line charging mode. The device and the method are used for simulating positive and negative hydrocarbon expulsion processes and laws.

Description

Technical Field

[0001] This invention relates to the field of deep oil and gas exploration technology, specifically to a dual overpressure bidirectional hydrocarbon expulsion simulation device and its simulation method. Background Technology

[0002] Deep formations are one of the key areas for future oil and gas exploration in China. Hydrocarbons generated in source rocks, driven by overpressure, expel hydrocarbons downwards, providing the material basis for deep hydrocarbon accumulation. Compaction and hydrocarbon generation are the main causes of overpressure in source rocks. Water in the source rock layer, unable to be discharged in time, causes its pressure to exceed the hydrostatic pressure. Existing simulation methods typically only consider the impact of hydrocarbon generation pressurization on hydrocarbon expulsion, migration, and accumulation, rarely considering the impact of compaction overpressure. The paper "Simulation Experiment and Mechanism Analysis of Lithologic Reservoir Accumulation Beneath Source Rocks" simulated the hydrocarbon migration and accumulation process under the dual overpressure of compaction and hydrocarbon generation. The paper simulated hydrocarbon generation pressurization using oil phase charging pressure and formation compaction by pressurizing the porous medium with jacks. However, limited by the upper limit of 6 MPa and the influence of the material's own strength, the compaction pressurization effect is difficult to effectively simulate and quantitatively characterize. The horizontal fluid pressure variation in source rock formations is minimal, with hydrocarbon expulsion primarily occurring vertically. The proportion of vertical hydrocarbon expulsion is a key parameter for evaluating deep hydrocarbon accumulation, yet no simulation devices or methods for this proportion have been found in the published literature. Therefore, understanding the bidirectional hydrocarbon expulsion characteristics of source rocks under the dual overpressure mechanism of compaction and hydrocarbon generation has become an urgent problem to be solved in order to meet the needs of deep hydrocarbon exploration. Summary of the Invention

[0003] One objective of this invention is to provide a dual-overpressure bidirectional hydrocarbon expulsion simulation device, which solves the problem that existing source rock overpressure simulation methods cannot effectively simulate the compaction and pressurization effect; another objective of this invention is to provide a simulation method for this dual-overpressure bidirectional hydrocarbon expulsion simulation device.

[0004] The technical solution adopted by this invention to solve its technical problem is as follows: This dual-overpressure bidirectional hydrocarbon expulsion simulation device includes a hydrocarbon expulsion model subsystem, a water phase pressurization device, an oil phase pressurization device, and a monitoring and acquisition subsystem. The hydrocarbon expulsion model subsystem includes a hydrocarbon expulsion model and a water tank. One pair of walls in the water tank are transparent. The hydrocarbon expulsion model is immersed in the water tank. The hydrocarbon expulsion model is a two-dimensional, visualized, filled model. The mudstone area surrounds the upper reservoir, the source rock layer, and the lower reservoir in the middle. Two glass plates sandwich the mudstone area, the upper reservoir, the source rock layer, and the lower reservoir in the middle. One glass plate is bonded to an adhesive strip, and the other glass plate has evenly distributed particles between it and the adhesive strip, allowing the interior of the hydrocarbon expulsion model to communicate with the surrounding water body. The plates are fastened together with C-clamps. The high-permeability zone of the source rock divides the source rock layer into an upper and lower section. The location of the high-permeability zone within the source rock layer is determined based on the location of the main source rock layer in the actual strata. The bottom of the water phase pressurization storage container of the water phase pressurization device is connected to the high-permeability zone of the source rock through the first water injection pipeline. The oil in the upper part of the transparent intermediate container of the oil phase pressurization device is connected to the high-permeability zone of the source rock through the oil phase injection pipeline. Oil or water enters the upper and lower sections of the source rock through the high-permeability zone of the source rock in a linear injection manner. The monitoring and acquisition subsystem includes a high-definition digital camera and a control computer. The high-definition digital camera is installed on the transparent wall of the water tank.

[0005] The method for creating the hydrocarbon expulsion model in the above scheme is as follows: A first glass plate is laid flat on a table, and adhesive strips are attached around its perimeter. The area enclosed by the adhesive strips is divided near the center into an upper reservoir, an upper section of the source rock, a high-permeability zone of the source rock, a lower section of the source rock, and a lower reservoir. A mudstone layer surrounds the upper reservoir, the upper section of the source rock, the high-permeability zone of the source rock, the lower section of the source rock, and the lower reservoir. The particle size of the mudstone is smaller than that of the particles in the upper and lower sections of the source rock; the particle size of the high-permeability zone of the source rock, the upper reservoir, and the lower reservoir are all smaller than those of the mudstone. The particle size is larger than that of the upper and lower sections of the source rock. After laying the high-permeability zone, upper section, lower section, reservoir area, and mudstone area of ​​the source rock, a layer of particles is evenly sprinkled on the surrounding adhesive strips. The second glass plate is then aligned and covered, and the two glass plates are fixed together with C-shaped clamps around the perimeter. The particles are then tapped and vibrated to ensure that they are evenly and compactly arranged. The hydrocarbon expulsion process is recorded by a camera through the transparent side of the water tank, and the transmitted light passing through the model is captured by a camera through the opaque side of the water tank. This data is used to calculate the amount of hydrocarbon expulsion in the model.

[0006] The above scheme includes a water phase pressurization column, a water phase pressurization faucet, a water phase pressurization storage container, and a water phase pressurization collection bottle. The water phase pressurization column is fixed on the water phase pressurization base, and the water phase pressurization storage container is placed on the water phase pressurization storage container tray. The water phase pressurization buckle secures the water phase pressurization storage container tray to the water phase pressurization column. The water phase pressurization storage container has a water phase pressurization overflow port. The water phase pressurization faucet replenishes the water phase pressurization storage container. When the replenishment flow rate is greater than the water phase filling flow rate, the excess water is discharged through the water phase pressurization overflow port into the water phase pressurization collection bottle, keeping the liquid level in the water phase pressurization storage container constant. By loosening the water phase pressurization buckle, the overall height of the water phase pressurization storage container can be adjusted to achieve different levels of pressurization.

[0007] The oil phase pressurization device in the above scheme includes an oil phase pressurization column, an oil phase pressurization faucet, an oil phase pressurization water storage container, a transparent intermediate container, and an oil phase pressurization water collection bottle. The oil phase pressurization column is fixed on the oil phase pressurization base, and the oil phase pressurization water storage container is placed on the oil phase pressurization water storage container tray. The oil phase pressurization buckle secures the oil phase pressurization water storage container tray to the oil phase pressurization column. The oil phase pressurization water storage container has an oil phase pressurization overflow port. The oil phase pressurization faucet replenishes the oil phase pressurization water storage container with liquid. When the replenishment flow rate is greater than the oil phase charging flow rate... At this time, excess water is discharged into the oil phase pressurized water collection bottle through the oil phase pressurization overflow port, keeping the liquid level in the oil phase pressurized water storage container constant; by loosening the oil phase pressurization buckle, the overall height of the oil phase pressurized water storage container can be adjusted to achieve different levels of pressurization; the bottom of the oil phase pressurized water storage container is filled with oil through the bottom inlet of the transparent intermediate container of the second water injection pipeline, and water is injected from the bottom of the transparent intermediate container, driving the oil in the upper part of the transparent intermediate container to enter the high permeability zone of the source rock in the hydrocarbon expulsion model through the oil phase injection pipeline.

[0008] In the above scheme, the thickness ratio of the upper section to the lower section of the source rock is 2:1.

[0009] In the above scheme, the two glass plates of the hydrocarbon expulsion model are placed corresponding to the transparent tank wall of the water tank.

[0010] The particles in the above scheme are glass microspheres.

[0011] The simulation method of the above-mentioned dual-overpressure bidirectional hydrocarbon expulsion simulation device: Simultaneously, oil-phase and water-phase pressurized injection was carried out on the source rock formation, with oil-phase pressure simulating hydrocarbon generation pressurization and water-phase pressure simulating compaction pressurization, to achieve simulation of dual overpressure hydrocarbon expulsion; Aqueous phase overpressure coefficient: α w =H1 / h (1) Oil phase overpressure coefficient α o =H2 / h (2); The amount of hydrocarbons expelled in the hydrocarbon expulsion model was measured using the transmitted light method, keeping the illumination conditions, shooting parameters, and particle arrangement in the model unchanged. Before injecting the oil phase, the light intensity of the area of ​​interest was obtained using a high-definition digital camera. I 0 After the oil phase enters the area of ​​interest, the light intensity of the area of ​​interest after filling is obtained under the same lighting conditions and imaging parameters. I 1 The cumulative difference between the two I = ∑(I 0 -I 1 ） The light absorption intensity of the oil phase, the magnitude of the light absorption intensity of the oil phase, and the volume of oil phase filling the region of interest are all factors in this equation. m o Proportional, that is: m o =k X I (3) In the formula: k The proportionality coefficient is obtained through calibration.

[0012] The simulation method of the above-mentioned dual-overpressure bidirectional hydrocarbon expulsion simulation device is as follows: (1) Saturate the hydrocarbon expulsion model with water: Slowly immerse the model in the water tank. Under the combined action of water pressure and osmosis, water enters the hydrocarbon expulsion model and the gas in the hydrocarbon expulsion model is discharged from the top of the model. (2) Determine the pressure coefficient: Determine the overpressure coefficient caused by compaction based on the actual geological conditions to be simulated. α w Pressure coefficient caused by hydrocarbon generation pressurization α o Measuring the immersion depth of the high-permeability zone of the source rock in the water tank. h Then determine according to formula (1) and formula (2). H1 and H2 The value is set to fill the first aqueous phase injection pipeline and the second aqueous phase injection pipeline with water, fill the oil phase injection pipeline with oil, fill the transparent intermediate container with water and oil, and close the aqueous phase booster valve and the oil phase booster valve. (3) Adjust the height of the transparent intermediate container so that the height of the oil-water interface is the same as the height of the high-permeability zone of the source rock in the hydrocarbon expulsion model; adjust the water phase pressurization tap and the oil phase pressurization tap to ensure that water overflows from the water phase pressurization storage container and the oil phase pressurization storage container during the simulation process, so as to keep the water phase pressurization degree and the oil phase pressurization degree constant. (4) Obtain the initial light intensity before filling by taking pictures. I 0 ; (5) Start charging: Open the water phase booster valve and the oil phase booster valve, and at the same time use a high-definition digital camera to record the light intensity distribution in the hydrocarbon expulsion model at different times; (6) Data processing: Use formula (3) to obtain the light intensity and oil content of the oil phase in the region of interest. Beneficial effects

[0013] 1. This invention provides a dual overpressure hydrocarbon expulsion simulation device and method for simulating the characteristics and patterns of hydrocarbon expulsion from source rocks, providing support for the exploration and evaluation of deep oil and gas resources. It can simulate the hydrocarbon expulsion process under both overpressure and compaction overpressure separately, or simulate the hydrocarbon expulsion process under the combined action of both.

[0014] 2. This invention provides a two-way hydrocarbon expulsion simulation experimental device and method for simulating positive and negative hydrocarbon expulsion processes and patterns, which facilitates the determination of oil and gas exploration directions, especially the evaluation of deep oil and gas reservoirs generated by backflow.

[0015] 3. This invention provides a method for quantitatively evaluating hydrocarbon emissions using transmitted light. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the dual overpressure bidirectional hydrocarbon expulsion simulation device of the present invention; Figure 2 This is a cross-sectional view of the hydrocarbon expulsion model AB in the figure.

[0017] Figure 3 This is a model for actual hydrocarbon emissions.

[0018] Figure 4 The diagram shows the effects of double overpressure hydrocarbon removal. In the diagram, A represents the dominant negative hydrocarbon removal from the source rock in the early stage, B represents the closure of the oil phase pressure valve after 38 minutes, C represents the continuous negative hydrocarbon removal under the action of compaction pressure, and D represents the large-scale positive hydrocarbon removal when negative hydrocarbon removal is restricted.

[0019] Figure 5 This is a graph showing the relationship between cumulative light intensity and cumulative injected oil volume.

[0020] Figure 6 This is a graph showing how the amount of oil injected changes over time.

[0021] In the diagram: 1-Water tank, 2-Hydrocarbon discharge model, 21-C-shaped clamp, 22-Rubber strip; 23-Mudstone area, 24-Lower reservoir, 25-Lower section of source rock, 26-High permeability zone of source rock, 27-Upper section of source rock, 28-Upper reservoir, 29-First glass plate, 210-Second glass plate, 31-Water phase pressurization base, 32-Water phase pressurization column, 33-Water phase pressurization buckle, 34-Water phase pressurization faucet, 35-Water phase pressurization storage container, 36-Water phase pressurization overflow outlet, 37-Water phase pressurization storage container tray, 38-Water phase pressurization 41-Water collection bottle, 42-Oil phase pressurization base, 43-Oil phase pressurization column, 44-Oil phase pressurization buckle, 45-Oil phase pressurization faucet, 46-Oil phase pressurization water storage container, 47-Oil phase pressurization overflow port, 48-Oil phase pressurization water storage container tray, 49-Transparent intermediate container, 51-First aqueous phase injection line, 52-Oil phase injection line, 53-Second aqueous phase injection line, 54-Oil phase pressurization valve, 55-Aqueous phase pressurization valve, 6-High-definition digital camera, 7-Camera control data cable, 8-Control computer. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings: Combination Figures 1-2 As shown, this dual-overpressure bidirectional hydrocarbon expulsion simulation device includes a hydrocarbon expulsion model subsystem, an aqueous phase pressurization device, an oil phase pressurization device, and a monitoring and acquisition subsystem. The hydrocarbon expulsion model subsystem includes a hydrocarbon expulsion model 2 and a water tank 1. The water tank 1 has a pair of transparent walls. The hydrocarbon expulsion model 2 is immersed in the water tank 1. The bottom of the aqueous phase pressurization storage container 35 of the aqueous phase pressurization device is connected to the high-permeability zone 26 of the source rock through the first water injection pipeline 51. The oil in the upper part of the transparent intermediate container 49 of the oil phase pressurization device is connected to the high-permeability zone 26 of the source rock through the oil phase injection pipeline 52. Oil or water enters the upper section 27 and the lower section 25 of the source rock through the high-permeability zone 26 of the source rock in a linear injection manner. The monitoring and acquisition subsystem includes a high-definition digital camera 6 and a control computer 8. The high-definition digital camera 6 is set at the transparent wall of the water tank 1.

[0023] The hydrocarbon expulsion model subsystem includes a hydrocarbon expulsion model 2 and a water tank 1. The hydrocarbon expulsion model is a two-dimensional visual filled model. The mudstone zone 23 surrounds the upper reservoir 28, the source rock layer, and the lower reservoir 24 in the middle. Two glass plates sandwich the mudstone zone 23, the upper reservoir 28, the source rock layer, and the lower reservoir 24 in the middle. The first glass plate 29 is bonded to the adhesive strip 22. The second glass plate 210 and the adhesive strip 22 are evenly distributed with particles, so that the interior of the hydrocarbon expulsion model 2 is connected to the surrounding water body. The two glass plates are fastened together by a C-shaped clamp 21. The high permeability zone 26 of the source rock divides the source rock layer into the upper section 27 and the lower section 25 of the source rock. The position of the high permeability zone 26 of the source rock in the source rock layer is determined according to the position of the main source rock layer in the actual strata. When constructing the model, the first glass plate 29 is laid flat on the table, and adhesive strips 22 are attached around its perimeter. These elastic strips divide the area enclosed by the adhesive strips 22 into several sections near the center: an upper source rock section 27, a lower source rock section 25, a high-permeability zone 26, an upper reservoir 28, a lower reservoir 24, and a mudstone zone 23. The core simulated area, excluding the mudstone zone, is arranged from top to bottom as follows: upper reservoir 28, upper source rock section 27, high-permeability zone 26, lower source rock section 25, and lower reservoir 24. To simulate uniform hydrocarbon discharge from the source rock layer, the location of the high-permeability zone 26 within the source rock layer is determined based on the actual location of the main source rock layer. The source rock layer is then divided into upper and lower sections. Fluid enters the upper and lower source rock sections via the high-permeability zone in a linear injection manner. The particle size of the filling microspheres follows these rules: the particle size in the mudstone area is smaller than that in the upper and lower sections of the source rock; the particle size in the high-permeability zone of the source rock, the upper reservoir, and the lower reservoir is larger than that in the upper and lower sections of the source rock. After laying the high-permeability zone, the lower section of the upper source rock, the reservoir area, and the mudstone area, a layer of microparticles is evenly sprinkled on the surrounding adhesive strips 22 to ensure communication between the fluid inside the model and the environmental fluid. The second glass plate 210 is then placed on top, and the two glass plates are fixed together with C-shaped clips 21 around the perimeter. The microsphere material inside the model is uniformly and compactly arranged by tapping and vibrating. One pair of sides of the water tank 1 is made of opaque material, and the other pair is made of transparent material. The transparent side is used to record the hydrocarbon expulsion process with a camera, while the opaque side is used to capture transmitted light that passes through the model, which can be used to calculate the amount of hydrocarbon expulsion in the model.

[0024] The water phase pressurization system includes a water phase pressurization base 31, a water phase pressurization column 32, a water phase pressurization buckle 33, a water phase pressurization faucet 34, a water phase pressurization storage container 35, a water phase pressurization overflow port 36, a water phase pressurization storage container tray 37, and a water phase pressurization water collection bottle 38. The water phase pressurization storage container tray 37 is fixed to the water phase pressurization column 32. The water phase pressurization buckle 33 is used to place the water phase pressurization storage container 37 and the water tank pressurization storage container 35. The water-phase pressurized storage container tray 37 is equipped with a water-phase pressurized overflow port 36. A water-phase pressurized faucet 34 replenishes the water-phase pressurized storage container 35 with liquid. When the replenishment flow rate exceeds the water-phase filling flow rate, excess water is discharged through the water-phase pressurized overflow port 36 into the water-phase pressurized water collection bottle 38, thus ensuring a constant liquid level in the water-phase pressurized storage container. Loosening the pressurization buckle allows adjustment of the overall height of the water-phase pressurized container, thereby achieving different levels of pressurization. The bottom of the water-phase pressurized container is connected to the high-permeability zone of the source rock in the model via a first water injection pipeline.

[0025] The oil phase pressurization device includes an oil phase pressurization column 42, an oil phase pressurization water tap 44, an oil phase pressurization water storage container 45, a transparent intermediate container 49, and an oil phase pressurization water collection bottle 48. The oil phase pressurization column 42 is fixed on the oil phase pressurization base 41. The oil phase pressurization water storage container 45 is placed on the oil phase pressurization water storage container tray 47. The oil phase pressurization buckle 43 secures the oil phase pressurization water storage container tray 47 to the oil phase pressurization column 42. The oil phase pressurization water storage container 45 has an oil phase pressurization overflow port 46. The oil phase pressurization water tap 44 replenishes the oil phase pressurization water storage container 45 with liquid. When the replenishment flow... When the volume exceeds the oil phase injection flow rate, the excess water is discharged through the oil phase pressurization overflow port 46 to the oil phase pressurization water collection bottle 48, keeping the liquid level in the oil phase pressurization water storage container constant. Different pressurization levels can be achieved by loosening the oil phase pressurization buckle and adjusting the overall height of the oil phase pressurization water storage container. Oil is filled into the transparent intermediate container through the bottom inlet of the second water injection pipeline 53, while water is injected from the bottom, driving the oil in the upper part of the transparent intermediate container 49 through the oil phase injection pipeline into the high-permeability zone of the source rock in the hydrocarbon expulsion model. The transparent intermediate container unit in the oil phase pressurization device is designed to facilitate control of the oil phase pressurization level.

[0026] The monitoring and acquisition subsystem includes a high-definition digital camera 6, a control computer 8, and a camera control data cable 7 between them. The camera can be controlled to take pictures remotely or at time intervals through the application on the control computer.

[0027] The basic principle of this invention is to simultaneously pressurize and inject both oil and water phases into the source rock formation, where the oil phase pressure simulates hydrocarbon generation pressurization and the water phase pressure simulates compaction pressurization, thereby achieving simulation of dual overpressure hydrocarbon expulsion.

[0028] The overpressure coefficient of the aqueous phase is: α w =H1 / h (1) According to the principle of communicating vessels, the oil phase overpressure coefficient α o =H2 / h (2) This invention uses the transmitted light method to measure hydrocarbon expulsion in a model, keeping the illumination conditions, imaging parameters, and model particle arrangement unchanged. Before injecting the oil phase, the light intensity of the area of ​​interest is obtained using a high-definition digital camera. I 0 After the oil phase enters the area of ​​interest, the light intensity of the area of ​​interest after filling is obtained under the same lighting conditions and imaging parameters. I 1 The cumulative difference between the two I = ∑(I 0 -I 1 ） The intensity of light absorbed by the oil phase is directly proportional to the volume of oil phase filling the region of interest, i.e.: m o =k•I (3) proportionality coefficient k This can be obtained through calibration.

[0029] The simulation method for this dual-overpressure, bidirectional hydrocarbon expulsion simulation device is as follows: (1) Making a two-dimensional visualization model of double overpressure hydrocarbon expulsion: Lay the first glass plate flat on the table and attach adhesive strips around it to divide the area enclosed by the adhesive strips into the high permeability zone of the source rock, the upper section of the source rock, the lower section of the source rock, the high permeability zone of the water phase, the reservoir, and the mudstone area. The high permeability zone of the source rock, the upper section of the source rock, the lower section of the source rock, and the reservoir are surrounded by the mudstone area. The particle size of the particles filled in the upper section of the source rock and the lower section of the source rock is smaller than that of the high permeability zone of the source rock and larger than that of the mudstone area. After filling with the adhesive strips around the perimeter, evenly sprinkle a layer of 40-80 mesh particles on the adhesive strips, align them and cover with the second glass plate. Use C-shaped clips to fix the first and second glass plates together. After tapping and vibrating, make the particle materials tightly arranged.

[0030] (2) Saturate the model with water: Slowly immerse the model in the water tank. Under the combined action of water pressure and seepage, water enters the model and the gas in the model is discharged from the top of the model.

[0031] (3) Determine the pressure coefficient: Determine the overpressure coefficient caused by compaction based on the actual geological conditions to be simulated. α w Pressure coefficient caused by hydrocarbon generation pressurization α oMeasuring the immersion depth of the high-permeability zone of the source rock in the water tank. h Based on formulas (1) and (2), determine H1 and H2 The value is determined by filling the first and second aqueous phase injection lines with water, filling the oil phase injection line with oil, filling the transparent intermediate container with water and oil, and then closing the aqueous phase pressurization valve and the oil phase pressurization valve.

[0032] (4) Connect the pipelines, passing the first aqueous phase injection pipeline and the oil phase injection pipeline through the rubber pads and mudstone area around the model to enter the high permeability zone of the source rock. Adjust the height of the transparent intermediate container so that the height of the oil-water interface is the same as the height of the high permeability zone of the source rock in the model. Adjust the aqueous phase injection tap and the oil phase injection tap to ensure that water overflows from the aqueous phase pressurization storage container and the oil phase pressurization storage container during the simulation, thereby maintaining a constant level of pressurization for both the aqueous and oil phases.

[0033] (5) Obtain the initial light intensity before filling by taking a picture. I 0 .

[0034] (6) Start charging: Open the water phase booster valve and the oil phase booster valve, and at the same time use a high-definition digital camera to record the light intensity distribution in the model at different times.

[0035] (7) Data processing: Use formula (3) to obtain the light intensity and oil content of the area of ​​interest. Example

[0036] Hydrocarbon expulsion simulation was conducted using source rocks from the Qingshankou Formation in a certain area of ​​the Songliao Basin, with the overpressure center located in the lower part of the source rock layer.

[0037] (1) Fabrication of a two-dimensional visualization model of double overpressure hydrocarbon expulsion: The first glass plate is laid flat on the table and adhesive strips are attached around it. The middle part of the area enclosed by the adhesive strips is divided from top to bottom into the upper reservoir, the upper section of the source rock, the high-permeability zone of the source rock, the lower section of the source rock, and the lower reservoir. The area is surrounded by mudstone. Considering the actual location of the overpressure center, the thickness ratio of the upper section of the source rock to the lower section of the source rock is 2:1. The glass plate used is 50cm×50cm and 0.5cm thick; the adhesive strips used are 0.2cm thick and 1cm wide; the granular material used is glass microspheres. The specifications of the glass microspheres used in the upper reservoir, the upper section of the source rock, the high-permeability zone of the source rock, the lower section of the source rock, the lower reservoir, and the mudstone area are 40 mesh, 80 mesh, 30 mesh, 80 mesh, 40 mesh, and 120 mesh, respectively. After filling the glass microspheres to be flush with the surrounding adhesive strips, evenly sprinkle a layer of 40-mesh glass microspheres on the adhesive strips, align and cover with the second glass plate, and use C-shaped clamps to fix the first and second glass plates together. After tapping and vibrating, the granular materials are made to be tightly arranged.

[0038] (2) Saturate the model with water: Slowly immerse the model in the water tank. Under the combined action of water pressure and seepage, water enters the model and the gas in the model is discharged from the top of the model.

[0039] (3) When the model was submerged in the water tank, the immersion depth of the high-permeability zone of the source rock was 69 cm. The overpressure coefficient caused by the compaction and hydrocarbon generation of the Qingshankou Formation source rock in this area was... α w Pressure coefficient caused by hydrocarbon generation pressurization α o The values ​​are 1.33 and 1.20 respectively. According to formula (1) and formula (2), H1 and H2 are calculated to be 91.8cm and 82.8cm respectively. The first aqueous phase injection pipeline and the second aqueous phase injection pipeline are filled with water, the oil phase injection pipeline is filled with oil, and the transparent intermediate container is filled with water and oil. The simulated oil phase is kerosene. To facilitate observation, the kerosene is dyed red with oil red dye.

[0040] (4) Connect the pipelines. Pass the first water phase injection pipeline and the oil phase injection pipeline through the rubber and mudstone areas around the model and into the high-permeability zone of the source rock. Similarly, pass the oil phase injection pipeline through the rubber and mudstone areas around the model and connect it to the high-permeability zone of the source rock. Adjust the height of the transparent intermediate container so that the height of the oil-water interface is the same as the height of the high-permeability zone of the source rock in the model. Close the water phase pressurization valve 55 and the oil phase pressurization valve 54, and adjust the water phase injection tap and the oil phase injection tap to ensure that the water phase and oil phase injection pressure is constant by overflow.

[0041] (5) Set the camera shooting parameters, and after focusing, adjust the shooting mode to manual mode to capture the initial light intensity before filling. I 0 .

[0042] (6) The aqueous phase pressurization valve 55 and the oil phase pressurization valve 54 were opened to start the simulation. At the same time, the light intensity distribution in the model at different times was recorded using a high-definition digital camera. After 38 minutes, the oil phase pressurization valve 54 was closed to observe the hydrocarbon expulsion characteristics under single aqueous phase pressurization. After 244 minutes, the oil phase pressurization valve 54 was reopened. The results showed that in the early stage of hydrocarbon generation and expulsion, due to the influence of the pressure center position, negative hydrocarbon expulsion was the main process. After the oil phase pressurization valve was closed after 38 minutes, considering that the oil phase of negative hydrocarbon expulsion had formed a continuous path, negative hydrocarbon expulsion would continue for a period of time under the action of aqueous phase overpressure. As the oil saturation in the source rock decreased, the rate of negative hydrocarbon expulsion decreased until it stopped. After the oil phase pressurization valve was reopened after 244 minutes, the results showed that positive hydrocarbon expulsion would only occur on a large scale when the space for negative hydrocarbon expulsion was limited.

[0043] (7) Data processing: Using formula (3), the light intensity and oil content of the area of ​​interest are obtained, from... Figure 6It can be seen that in the early stage, negative hydrocarbon emissions were dominant, while in the later stage, positive hydrocarbon emissions were dominant.

Claims

1. A dual overpressure bidirectional hydrocarbon drainage simulation device, characterized in that: The simulation device comprises a hydrocarbon expulsion model subsystem, a water phase pressurization device, an oil phase pressurization device and a monitoring and collecting subsystem, the hydrocarbon expulsion model subsystem comprises a hydrocarbon expulsion model and a water tank, the water tank has a pair of transparent tank walls, the hydrocarbon expulsion model is immersed in the water tank, the hydrocarbon expulsion model is a two-dimensional visual filling model, a mudstone area surrounds an upper reservoir, a source rock layer and a lower reservoir, two glass plates sandwich the mudstone area, the upper reservoir, the source rock layer and the lower reservoir, one glass plate is bonded with a rubber strip, the other glass plate is uniformly distributed with particles between the rubber strips, the interior of the hydrocarbon expulsion model is in communication with the surrounding water, the two glass plates are fastened together by a C-shaped clamp, a high permeability zone of the source rock divides the source rock layer into an upper source rock section and a lower source rock section, the position of the high permeability zone in the source rock layer is determined according to the position of the main source rock layer in the actual stratum; the bottom of a water phase pressurization storage container of the water phase pressurization device is connected with the high permeability zone of the source rock through a first water injection pipeline, the oil at the upper part of a transparent intermediate container of the oil phase pressurization device is connected with the high permeability zone of the source rock through an oil phase injection pipeline, the oil or water enters the upper source rock section and the lower source rock section in a linear filling manner through the high permeability zone of the source rock; the monitoring and collecting subsystem comprises a high-definition digital camera and a control computer, the high-definition digital camera is arranged at the transparent tank wall of the water tank.

2. The dual overpressure bidirectional hydrocarbon drainage simulation device according to claim 1, characterized in that: The hydrocarbon expulsion model manufacturing method comprises the following steps: laying a first glass plate on a table top, pasting rubber strips around the first glass plate, dividing the area surrounded by the rubber strips into an upper reservoir, an upper source rock section, a high permeability zone of the source rock, a lower source rock section, a lower reservoir, surrounding the upper reservoir, the upper source rock section, the high permeability zone of the source rock, the lower source rock section and the lower reservoir with a mudstone layer, and making the particle size of the mudstone area smaller than the particle size of the upper source rock section and the lower source rock section; making the particle size of the high permeability zone of the source rock, the upper reservoir and the lower reservoir greater than the particle size of the upper source rock section and the lower source rock section; after laying the high permeability zone of the source rock, the upper source rock section, the lower source rock section, the reservoir area and the mudstone area, uniformly scattering particles on the rubber strips around the first glass plate, aligning a second glass plate, fastening the two glass plates together by a C-shaped clamp around the first glass plate, and knocking and oscillating to make the particles uniformly and tightly arranged; recording the hydrocarbon expulsion process by using a camera through the transparent side of the water tank, and making the camera shoot the transmitted light through the model through the opaque side of the water tank, so as to calculate the hydrocarbon expulsion amount in the model.

3. The dual overpressure bidirectional hydrocarbon drainage simulation device according to claim 2, characterized in that: The water phase pressurization comprises a water phase pressurization column, a water phase pressurization faucet, a water phase pressurization storage container and a water phase pressurization water collecting bottle, the water phase pressurization column is fixed on a water phase pressurization base, the water phase pressurization storage container is placed on a water phase pressurization storage container tray, a water phase pressurization buckle fastens the water phase pressurization storage container tray on the water phase pressurization column, the water phase pressurization storage container is provided with a water phase pressurization overflow port, the water phase pressurization faucet supplies liquid to the water phase pressurization storage container, when the liquid supply flow is greater than the water phase filling flow, the excess water is discharged to the water phase pressurization water collecting bottle through the water phase pressurization overflow port, so that the liquid level in the water phase pressurization storage container is constant; by loosening the water phase pressurization buckle, the overall height of the water phase pressurization storage container is adjusted, so that different pressurization degrees are realized.

4. The dual overpressure bidirectional hydrocarbon drainage simulation device according to claim 3, characterized in that: The oil phase pressurization device comprises an oil phase pressurization column, an oil phase pressurization faucet, an oil phase pressurization water storage container, a transparent intermediate container and an oil phase pressurization water collection bottle, the oil phase pressurization column is fixed on an oil phase pressurization base, the oil phase pressurization water storage container is placed on an oil phase pressurization water storage container tray, the oil phase pressurization buckle fastens the oil phase pressurization water storage container tray on the oil phase pressurization column, the oil phase pressurization water storage container is provided with an oil phase pressurization overflow port, the oil phase pressurization faucet replenishes the oil phase pressurization water storage container, when the replenishing flow is greater than the oil phase filling flow, the excess water is discharged to the oil phase pressurization water collection bottle through the oil phase pressurization overflow port, so that the liquid level in the oil phase pressurization water storage container is constant; the overall height of the oil phase pressurization water storage container is adjusted by loosening the oil phase pressurization buckle, so that different pressurization degrees are realized; the bottom of the oil phase pressurization water storage container is connected to the bottom inlet of the transparent intermediate container through a second water injection pipeline, oil is filled into the transparent intermediate container, and water is injected into the transparent intermediate container from the bottom, so that the oil in the upper part of the transparent intermediate container is driven to enter the hydrocarbon source rock high permeability zone in the hydrocarbon expulsion model through the oil phase injection pipeline.

5. The dual overpressure bidirectional hydrocarbon drainage simulation device according to claim 4, characterized in that: The thickness ratio of the upper layer of the hydrocarbon source rock to the lower layer of the hydrocarbon source rock is 2:

1.

6. The dual overpressure bidirectional hydrocarbon drainage simulation device of claim 4, wherein: The two glass plates of the hydrocarbon expulsion model correspond to the transparent tank wall of the water tank.

7. The dual overpressure bidirectional hydrocarbon drainage simulation device of claim 4, wherein: The particles are glass beads.

8. A simulation method of the dual overpressure bidirectional hydrocarbon drainage analog device of claim 7, characterized in that: Meanwhile, the hydrocarbon source rock layer is filled with oil phase and water phase under pressure, wherein the oil phase pressure simulates hydrocarbon generation pressurization, and the water phase pressure simulates compaction pressurization, so as to realize double overpressure hydrocarbon expulsion simulation. The water phase overpressure coefficient is: α w =H1 / h （1） The oil phase overpressure coefficient is: α o =H2 / h （2）； The amount of hydrocarbons expelled in the hydrocarbon expulsion model was measured using the transmitted light method, keeping the illumination conditions, shooting parameters, and particle arrangement in the model unchanged. Before injecting the oil phase, the light intensity of the area of ​​interest was obtained using a high-definition digital camera. I 0 After the oil phase enters the area of ​​interest, the light intensity of the area of ​​interest after filling is obtained under the same lighting conditions and imaging parameters. I 1 The cumulative difference between the two I=∑(I 0 -I 1 ） The light absorption intensity of the oil phase, the magnitude of the light absorption intensity of the oil phase, and the volume of oil phase filling the region of interest are all factors in this equation. m o Proportional, that is: m o =k X I （3） In the formula: k is a proportionality factor obtained by calibration.

9. The method of claim 8, wherein the method further comprises: determining the pressure of the fluid in the first and second chambers; and determining the pressure of the fluid in the first and second chambers. The method comprises the following steps: (1) saturate the hydrocarbon expulsion model with water: slowly immerse the model in the water in the water tank, under the joint action of water pressure and imbibition, water enters the hydrocarbon expulsion model, and the gas in the hydrocarbon expulsion model is discharged from the top of the model; (2) determining the pressure coefficient: determining the overpressure coefficient caused by compaction according to the actual geological conditions to be simulated α w and the pressure coefficient caused by hydrocarbon generation and pressure increase α o measuring the submersion depth of the high-permeability zone of the source rock in the water tank h determining the values of and according to formula (1) and formula (2) H1 and H2 filling the first water phase injection pipeline and the second water phase injection pipeline with water, filling the oil phase injection pipeline with oil, filling the transparent intermediate container with water and oil, and closing the water phase pressure increasing valve and the oil phase pressure increasing valve; (3) adjust the height of the transparent intermediate container so that the height of the oil-water interface in the transparent intermediate container is the same as the height of the hydrocarbon source rock high permeability zone in the hydrocarbon expulsion model; adjust the water phase pressurization faucet and the oil phase pressurization faucet, and in the form of overflow, ensure that the liquid level in the water phase pressurization water storage container and the oil phase pressurization water storage container always has water overflowing during the simulation process, so as to keep the water phase pressurization degree and the oil phase pressurization degree constant; (4) photographing to obtain initial light intensity before filling I 0 ; (5) start filling: open the water phase pressurization valve and the oil phase pressurization valve, and simultaneously record the light intensity distribution in the hydrocarbon expulsion model at different times by using a high-definition digital camera; (6) data processing: obtain the oil phase absorption light intensity and the oil volume of the concerned area by using formula (3).

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