Method and apparatus for determining high-pressure physical property parameters of foamy oil

Abstract

Provided in the embodiments of the present application are a method and apparatus for determining high-pressure physical property parameters of foamy oil. The method comprises: acquiring experimental data from a simulation experiment of foamy oil under intermittent cold production; on the basis of the experimental data, establishing a first model and a second model; then, on the basis of the first model and the second model, acquiring a relationship curve of the pseudo bubble-point pressure, system pressure and volume of the foamy oil under the state of intermittent cold production; and on the basis of the relationship curve, finally determining high-pressure physical property parameters of the foamy oil under the state of intermittent cold production. In the embodiments of the present application, high-pressure physical property parameters of foamy oil under the state of intermittent cold production can be accurately determined.

Description

Methods and apparatus for determining high-pressure physical properties of foamed oil

[0001] This application claims priority to Chinese Patent Application No. 202411929480.X, filed on December 25, 2024, entitled “Method and Apparatus for Determining High-Pressure Physical Property Parameters of Foam Oil”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of oil reservoir development technology, and in particular to a method and apparatus for determining the high-pressure physical property parameters of foamed oil. Background Technology

[0003] Currently, with global conventional oil and gas resources becoming increasingly depleted, the importance of unconventional petroleum resources such as foam oil is becoming increasingly prominent. During the depressurization and cold production process of foam oil reservoirs, the dissolved gas released does not immediately coalesce to form a continuous gas phase for rapid production. Instead, it remains in the oil phase as dispersed bubbles, flowing with the crude oil, forming the so-called "foam oil flow." This continues until the pressure drops below the pseudo-foam point pressure (the pressure point at which dispersed bubbles begin to coalesce in large numbers, producing a continuous gas phase), at which point the oil and gas finally separate, becoming conventional dissolved gas drive.

[0004] However, in actual field production, due to limitations such as production conditions, frequent well shutdowns and restarts, or even the complete shutdown of the oilfield, during the depressurization and cold extraction process of foamed oil reservoirs, will lead to the reservoir being in a non-equilibrium production state. Foamed oil is a thermodynamically non-equilibrium system. During the shutdown phase, the pressure drop rate and production pressure difference tend to be zero, and the dispersed bubbles in the foamed oil tend to gradually coalesce to form free gas, which will have a complex impact on the high-pressure physical properties of the foamed oil, thereby affecting the development effect.

[0005] Currently, the high-pressure physical properties of foam oil under conventional crude oil and continuous production conditions are mainly determined using high-temperature and high-pressure formation fluid analyzers and theoretical formulas. This method is time-consuming, labor-intensive, and costly, and is not applicable to determining the high-pressure physical properties of foam oil under intermittent cold production conditions. Therefore, determining the high-pressure physical properties of foam oil under intermittent cold production conditions is an urgent problem to be solved. Summary of the Invention

[0006] This application provides a method and apparatus for determining the high-pressure physical properties of foamed oil under intermittent cold extraction production conditions.

[0007] In a first aspect, embodiments of this application provide a method for determining the high-pressure physical property parameters of foamed oil, including:

[0008] Experimental data were obtained from a simulation experiment of intermittent cold-extraction foam oil.

[0009] Based on experimental data, a first model and a second model were established. The first model is a calculation model for the pseudo-bubble point pressure of foam oil under intermittent cold production conditions, and the second model is a model for the relationship between pressure and volume of the oil-gas system of foam oil under intermittent cold production conditions.

[0010] Based on the first and second models, the relationship curves between the foam oil's pseudo-foaming point pressure, system pressure, and volume under intermittent cold-extraction foam oil conditions were obtained.

[0011] Based on the relationship curve, the high-pressure physical properties of foam oil under intermittent cold production conditions are determined.

[0012] In one possible implementation, the high-pressure physical properties of the foam oil under intermittent cold-harvested conditions are determined based on the relationship curve, including:

[0013] Based on the relationship curve, obtain the volume of the foamed oil-gas system under intermittent cold production conditions;

[0014] Based on the volume of the oil and gas system, high-pressure physical property parameters are obtained.

[0015] In one possible implementation, the high-pressure physical properties include at least one of the following:

[0016] Foam oil volume factor, foam oil dissolved gas-oil ratio, or foam oil viscosity.

[0017] In one possible implementation, the volume of the foamed oil-gas system under intermittent cold recovery production conditions is obtained based on the relationship curve, including:

[0018] Based on the relationship curve, the amount of gas released, the first coefficient, the second coefficient, and the time for the foam oil to reach equilibrium under equilibrium conditions are obtained. Among them, the first coefficient and the second coefficient are the bubble growth coefficients in the foam oil flow and oil-gas two-phase flow processes.

[0019] The volume of the foam oil gas system under intermittent cold production conditions is obtained based on the amount of gas released, the first coefficient, the second coefficient, and the time it takes for the foam oil to reach equilibrium.

[0020] In one possible implementation, obtaining the amount of gas released in equilibrium based on the relationship curve includes: obtaining the molar volume of the gas released, the total volume of the foam oil in equilibrium at the current pressure, and the oil phase volume of the foam oil in equilibrium at the current pressure based on the relationship curve.

[0021] The amount of gas released under equilibrium conditions is obtained based on the molar volume of the gas released, the total volume of the foamed oil in equilibrium under the current pressure, and the volume of the oil phase in equilibrium under the current pressure.

[0022] In one possible implementation, obtaining the molar volume of the evolved gas based on the relationship curve includes:

[0023] Based on the relationship curve, obtain the attraction coefficient and critical property constant of the gas system;

[0024] The molar volume of the evolved gas is obtained based on the attraction coefficient and the critical property constant.

[0025] In one possible implementation, the gas system includes multiple gases;

[0026] Based on the relationship curve, obtain the attraction coefficient and critical property constants of the gas system, including:

[0027] Obtain the relative temperature based on the relationship curve;

[0028] Based on the relative temperature and critical temperature, obtain the attraction coefficient and critical property constant of each gas in the gas system;

[0029] Based on the attraction coefficient and critical property constant of each gas, the attraction coefficient and critical property constant of the gas system are obtained.

[0030] In one possible implementation, obtaining the relative temperature based on the relationship curve includes:

[0031] Based on the relationship curve, obtain the critical temperature and reservoir temperature;

[0032] The relative temperature is obtained based on the critical temperature and the reservoir temperature.

[0033] In one possible implementation, the time it takes for the first coefficient, the second coefficient, and the foam oil to reach equilibrium is determined using a particle swarm optimization algorithm.

[0034] In one possible implementation, the foam oil volume factor is calculated based on the foam oil volume, the dead oil volume under standard conditions, the dispersed gas volume, and the oil phase volume.

[0035] In one possible implementation, the foam oil-to-dissolved gas-oil ratio is calculated based on the free gas volume, the initial dissolved gas volume, the total volume of the gas system, the foam oil volume, and the molar volume of the precipitated gas.

[0036] In one possible implementation, the foam oil viscosity is calculated based on the dead oil viscosity of the foam oil, the foam oil viscosity coefficient, the gas system pressure, the bubble point pressure, the original dissolved gas-oil ratio, and the dissolved gas-oil ratio of the foam oil.

[0037] Secondly, embodiments of this application provide a device for determining the high-pressure physical property parameters of foamed oil, comprising:

[0038] The acquisition module is used to acquire experimental data from simulation experiments of intermittent cold-harvested foam oil.

[0039] The processing module is used to establish a first model and a second model based on experimental data. The first model is a calculation model of the pseudo-bubble point pressure of foam oil under intermittent cold production conditions, and the second model is a model of the relationship between pressure and volume of the oil-gas system of foam oil under intermittent cold production conditions.

[0040] The processing module is also used to obtain the relationship curves between the foam oil pseudo-foaming point pressure, system pressure and volume under the condition of intermittent cold-extracted foam oil, based on the first model and the second model.

[0041] The determination module is used to determine the high-pressure physical property parameters of foam oil under intermittent cold-extraction conditions based on the relationship curve.

[0042] In one possible implementation, the high-pressure physical properties of the foam oil under intermittent cold-harvested conditions are determined based on the relationship curve, including:

[0043] Based on the relationship curve, obtain the volume of the foamed oil-gas system under intermittent cold production conditions;

[0044] Based on the volume of the oil and gas system, high-pressure physical property parameters are obtained.

[0045] In one possible implementation, the high-pressure physical properties include at least one of the following:

[0046] Foam oil volume factor, foam oil dissolved gas-oil ratio, or foam oil viscosity.

[0047] In one possible implementation, the volume of the foamed oil-gas system under intermittent cold recovery production conditions is obtained based on the relationship curve, including:

[0048] Based on the relationship curve, the amount of gas released, the first coefficient, the second coefficient, and the time for the foam oil to reach equilibrium under equilibrium conditions are obtained. Among them, the first coefficient and the second coefficient are the bubble growth coefficients in the foam oil flow and oil-gas two-phase flow processes.

[0049] The volume of the foam oil gas system under intermittent cold production conditions is obtained based on the amount of gas released, the first coefficient, the second coefficient, and the time it takes for the foam oil to reach equilibrium.

[0050] In one possible implementation, obtaining the amount of gas released in equilibrium based on the relationship curve includes: obtaining the molar volume of the gas released, the total volume of the foam oil in equilibrium at the current pressure, and the oil phase volume of the foam oil in equilibrium at the current pressure based on the relationship curve.

[0051] The amount of gas released under equilibrium conditions is obtained based on the molar volume of the gas released, the total volume of the foamed oil in equilibrium under the current pressure, and the volume of the oil phase in equilibrium under the current pressure.

[0052] In one possible implementation, obtaining the molar volume of the evolved gas based on the relationship curve includes:

[0053] Based on the relationship curve, obtain the attraction coefficient and critical property constant of the gas system;

[0054] The molar volume of the evolved gas is obtained based on the attraction coefficient and the critical property constant.

[0055] In one possible implementation, the gas system includes multiple gases;

[0056] Based on the relationship curve, obtain the attraction coefficient and critical property constants of the gas system, including:

[0057] Obtain the relative temperature based on the relationship curve;

[0058] Based on the relative temperature and critical temperature, obtain the attraction coefficient and critical property constant of each gas in the gas system;

[0059] Based on the attraction coefficients and critical property constants of each gas, the attraction coefficients and critical property constants of the gas system are obtained.

[0060] In one possible implementation, obtaining the relative temperature based on the relationship curve includes:

[0061] Based on the relationship curve, obtain the critical temperature and reservoir temperature;

[0062] The relative temperature is obtained based on the critical temperature and the reservoir temperature.

[0063] In one possible implementation, the time it takes for the first coefficient, the second coefficient, and the foam oil to reach equilibrium is determined using a particle swarm optimization algorithm.

[0064] In one possible implementation, the foam oil volume factor is calculated based on the foam oil volume, the dead oil volume under standard conditions, the dispersed gas volume, and the oil phase volume.

[0065] In one possible implementation, the foam oil-to-dissolved gas-oil ratio is calculated based on the free gas volume, the initial dissolved gas volume, the total volume of the gas system, the foam oil volume, and the molar volume of the precipitated gas.

[0066] In one possible implementation, the foam oil viscosity is calculated based on the dead oil viscosity of the foam oil, the foam oil viscosity coefficient, the gas system pressure, the bubble point pressure, the original dissolved gas-oil ratio, and the dissolved gas-oil ratio of the foam oil.

[0067] Thirdly, embodiments of this application provide an electronic device, including: a memory and a processor;

[0068] The memory stores the instructions that the computer executes;

[0069] The processor executes computer execution instructions stored in memory, causing the processor to perform the first aspect and / or various possible implementations of the first aspect as described above.

[0070] Fourthly, embodiments of this application provide a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the first aspect and / or various possible implementations of the first aspect.

[0071] Fifthly, embodiments of this application provide a computer program product, including a computer program that, when executed by a processor, implements the first aspect and / or various possible implementations of the first aspect.

[0072] This application provides a method and apparatus for determining the high-pressure physical properties of foamed oil. It involves acquiring experimental data from a simulation experiment of intermittent cold-production foamed oil; establishing a first model and a second model based on the experimental data; then, using the first and second models, obtaining the relationship curves between the simulated bubble point pressure, system pressure, and volume of the foamed oil under intermittent cold-production conditions; and finally, determining the high-pressure physical properties of the foamed oil under these conditions based on the relationship curves. This application provides a method for quickly and accurately determining the high-pressure physical properties of foamed oil under intermittent cold-production production conditions. Attached Figure Description

[0073] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0074] Figure 1 is a flowchart illustrating a method for determining the high-pressure physical property parameters of foamed oil according to an embodiment of this application.

[0075] Figure 2 is a schematic diagram of the pressure and volume relationship curves of the foamed oil gas system under intermittent cold production conditions provided in the embodiments of this application;

[0076] Figure 3 shows the microscopic characteristics of foamed oil under intermittent cold extraction state at each pressure level provided in the embodiments of this application;

[0077] Figure 4 shows the pressure drop rate of 1 MPa·h provided in the embodiment of this application. -1 A schematic diagram of the pressure and volume relationship curves of the foamed oil gas system under intermittent cold extraction production conditions with a shutdown duration of 5 hours;

[0078] Figure 5 shows the pressure drop rate of 1 MPa·h provided in the embodiment of this application. -1 A schematic diagram of the pressure and volume relationship curves of the foamed oil gas system under intermittent cold extraction production conditions with a shutdown duration of 10 hours;

[0079] Figure 6 shows the pressure drop rate of 1 MPa·h provided in the embodiment of this application. -1 A schematic diagram of the pressure and volume relationship curves of the foamed oil gas system under intermittent cold extraction production conditions with a shutdown duration of 20 hours;

[0080] Figure 7 shows the pressure drop rate of 2 MPa·h provided in the embodiment of this application. -1 A schematic diagram of the pressure and volume relationship curves of the foamed oil gas system under intermittent cold extraction production conditions with a shutdown duration of 5 hours;

[0081] Figure 8 shows the pressure drop rate of 2 MPa·h provided in the embodiment of this application. -1 A schematic diagram of the pressure and volume relationship curves of the foamed oil gas system under intermittent cold extraction production conditions with a shutdown duration of 10 hours;

[0082] Figure 9 shows the pressure drop rate of 2 MPa·h provided in the embodiment of this application. -1 A schematic diagram of the pressure and volume relationship curves of the foamed oil gas system under intermittent cold extraction production conditions with a shutdown duration of 10 hours;

[0083] Figure 10 shows the pressure drop rate of 1 MPa·h provided in the embodiment of this application. -1 Comparison of experimental and calculated results of pressure and volume relationship curves of foam oil gas system under intermittent cold extraction production conditions with different shutdown times;

[0084] Figure 11 shows the pressure drop rate of 2 MPa·h provided in the embodiment of this application. -1 Comparison of experimental and calculated results of pressure and volume relationship curves of foam oil gas system under intermittent cold extraction production conditions with different shutdown times;

[0085] Figure 12 is a schematic flowchart of a method for determining the high-pressure physical property parameters of foamed oil according to an embodiment of this application;

[0086] Figure 13 is a schematic diagram of the structure of a high-pressure physical property parameter determination device for foamed oil provided in this application;

[0087] Figure 14 is a schematic diagram of the structure of an electronic device provided in this application.

[0088] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0089] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0090] Currently, global conventional oil and gas resources are becoming increasingly depleted, highlighting the growing importance of unconventional oil resources such as foam oil.

[0091] During the depressurization and cold production process of foam oil reservoirs, the dissolved gas released does not immediately coalesce to form a continuous gas phase for rapid production. Instead, it remains in the oil phase as dispersed bubbles, flowing with the crude oil, forming what is known as a "foam flow." This continues until the pressure drops below the pseudo-foam point pressure (the pressure point where dispersed bubbles begin to coalesce in large numbers, producing a continuous gas phase), at which point the oil and gas finally separate, becoming conventional dissolved gas drive. The foam flow improves crude oil fluidity, delays gas production, and increases elastic drive energy, enabling the cold production recovery rate of foam oil reservoirs to reach up to approximately 12%. Forming a stable foam flow and fully utilizing the oil displacement effect of foam oil are crucial for the efficient development of foam oil reservoirs.

[0092] However, in actual field production, due to limitations such as production conditions, frequent well restarts or even the entire oilfield shutting down during the depressurization and cold extraction process of foam oil reservoirs will result in the reservoir being in an intermittent cold extraction production state. Foam oil is a thermodynamically non-equilibrium system; during the shutdown phase, the pressure drop rate and production pressure differential approach zero, and the dispersed bubbles in the foam oil tend to gradually coalesce into free gas, which will have a complex impact on the high-pressure physical properties of the foam oil, thus affecting the development effect. Currently, the high-pressure physical properties of conventional crude oil and foam oil under continuous production conditions are mainly determined using high-temperature, high-pressure formation fluid analyzers and theoretical formulas. This method is time-consuming, labor-intensive, and costly, and is difficult to apply to the determination of high-pressure physical properties of foam oil under intermittent cold extraction production conditions. Currently, there is still a lack of convenient and effective methods for determining the high-pressure physical properties of foam oil under intermittent cold extraction production conditions.

[0093] Therefore, this application proposes a method and apparatus for determining the high-pressure physical properties of foamed oil. The method involves acquiring experimental data from a simulation experiment of intermittent cold-production foamed oil; establishing a first model and a second model based on the experimental data; then, using the first and second models, obtaining the relationship curves between the simulated bubble point pressure, system pressure, and volume of the foamed oil under intermittent cold-production conditions; finally, determining the high-pressure physical properties of the foamed oil under these conditions based on the relationship curves. In the embodiments of this application, the high-pressure physical properties of foamed oil under intermittent cold-production production conditions can be determined quickly and accurately.

[0094] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0095] Figure 1 is a schematic flowchart of a method for determining the high-pressure physical property parameters of foamed oil according to an embodiment of this application. As shown in Figure 1, the method for determining the high-pressure physical property parameters of foamed oil in this embodiment includes the following steps:

[0096] S101. Obtain experimental data from the simulation experiment of intermittent cold-extraction foam oil.

[0097] Specifically, the simulation experiment of intermittent cold-production foam oil includes the following steps:

[0098] Step 1: Clean the formation fluid mixing apparatus and the intermediate container (e.g., high-pressure gas cylinder, gas sampling cylinder, etc.) containing the mixing gas (e.g., natural gas). Pour the oil sample (e.g., petroleum) into the formation fluid mixing apparatus, leaving space for the mixing gas. Then, use a vacuum pump to evacuate the intermediate container for at least 24 hours. Measure the required mixing gas and transfer it into the formation fluid mixing apparatus. Finally, heat and pressurize the formation fluid mixing apparatus to formation conditions and stir for at least 24 hours to ensure thorough mixing of the oil sample and the mixing gas, forming the experimental formation oil sample.

[0099] In this embodiment, the formation fluid mixing apparatus and the intermediate container containing the mixing gas are cleaned. The oil sample to be used is introduced into the formation fluid mixing apparatus, with a 50ml space reserved for the mixing gas. Then, the intermediate container is evacuated for 48 hours using a vacuum pump. The required mixing gas is measured and transferred into the formation fluid mixing apparatus. Finally, the formation fluid mixing apparatus is heated and pressurized to formation conditions (formation temperature 54.2℃ and formation pressure 8.65MPa), and stirred for 48 hours to ensure thorough mixing of the oil sample and the mixing gas, forming the experimental formation oil sample.

[0100] Step 2: To prevent formation oil sample degassing, maintain the PVT cylinder temperature at the formation temperature. Under conditions higher than the formation pressure, introduce a certain amount of formation oil sample from the formation fluid mixing instrument into the PVT cylinder and stir thoroughly for more than 24 hours.

[0101] In this embodiment of the application, the temperature of the PVT cylinder is maintained at the formation temperature of 54.2°C. Under the condition of 10 MPa, 200 ml of formation oil sample is introduced from the formation fluid mixing instrument into the PVT cylinder and stirred thoroughly for 48 hours.

[0102] Step 3: Increase the volume of the PVT cylinder to reduce its pressure, and gradually reduce the pressure at a certain rate. In order to form a foamy oil state, no stirring is performed after each stage of pressure reduction until the pressure drops to the reservoir abandonment pressure, thus simulating the depressurization and cold production process of a foamy oil reservoir.

[0103] In this process, when the pressure drops to a certain level, the pressure reduction is stopped, and the PVT cylinder remains stationary for a period of time to simulate the intermittent cold production process. During this process, the pressure and volume values ​​of the foam oil gas system are read, and the pressure-volume relationship curve of the foam oil gas system under intermittent cold production conditions is plotted. The simulated bubble point pressure of the foam oil is determined based on the inflection point of the curve.

[0104] In this embodiment, the pressure is reduced by increasing the volume of the PVT cylinder at a rate of 1 MPa / h. To create a foamy oil state, no stirring is performed after each pressure reduction until the pressure drops to the reservoir abandonment pressure of 0.101 MPa, simulating the depressurization cold production process of a foamy oil reservoir. When the pressure drops to 4 MPa, the depressurization is stopped, and the PVT cylinder remains stationary for a period of time, simulating an intermittent cold production process. During this process, the system pressure and volume values ​​are read, and a system pressure-volume relationship curve under intermittent cold production conditions is plotted (as shown in Figure 2). Based on the inflection point of the curve, the pseudo-foaming point pressure of the foamy oil is determined to be 2.1 MPa.

[0105] Figure 2 is a schematic diagram of the pressure and volume relationship curves of the foam oil gas system under intermittent cold production conditions provided in the embodiments of this application. As shown in Figure 2, the circles are used to indicate the system pressure and volume values ​​read during the experiment; the horizontal axis represents the pressure of the foam oil gas system under intermittent cold production conditions, in MPa; the vertical axis represents the volume of the foam oil gas system under intermittent cold production conditions, in ml.

[0106] Step 4: Repeat steps 2 and 3. After each depressurization, introduce a portion of the foam oil into a high-temperature, high-pressure microscopic viewing window to observe the microscopic characteristics of the foam oil under intermittent cold extraction conditions (as shown in Figure 3).

[0107] Figure 3 shows the microscopic characteristics of foamed oil under intermittent cold production conditions at each pressure level provided in the embodiments of this application. As shown in Figure 3, from left to right, the microscopic characteristics of foamed oil under intermittent cold production conditions are shown at pressures of 5 MPa, 4.95 MPa, 4 MPa, 4.77 MPa, 4.27 MPa, 2.27 MPa, 1.77 MPa, and 0.77 MPa, respectively.

[0108] Step 5: Repeat steps 2-4, changing the pressure drop rate and shutdown duration, and study the effects of pressure drop rate and shutdown duration on the pseudo-bubble point pressure of foam oil and the pressure-volume relationship curve of foam oil gas system under intermittent cold production conditions.

[0109] In this embodiment, the effects of pressure drop rate (1 MPa / h, 2 MPa / h) and shutdown duration (5 h, 10 h, 20 h) on the pseudo-bubbling point pressure of foamed oil and the relationship between system pressure and volume under intermittent cold recovery production conditions were studied.

[0110] Table 1

[0111] As shown in Table 1, with the increase of pressure drop rate and the length of shutdown time, the pseudo-foaming point pressure of foam oil gradually increases.

[0112] The pressure-volume relationship curves of the system under different shutdown durations and pressure drop rates are shown in Figures 4 to 9.

[0113] Figure 4 shows the pressure drop rate of 1 MPa·h provided in the embodiment of this application. -1 Figure 4 shows a schematic diagram of the pressure and volume relationship curves of the foam oil gas system under intermittent cold production conditions with a shutdown duration of 5 hours. As shown in Figure 4, the dots indicate the system pressure and volume values ​​read during the experiment; the horizontal axis represents the pressure of the foam oil gas system under intermittent cold production conditions, in MPa; and the vertical axis represents the volume of the foam oil gas system under intermittent cold production conditions, in ml.

[0114] Figure 5 shows the pressure drop rate of 1 MPa·h provided in the embodiment of this application. -1 Figure 5 shows a schematic diagram of the pressure and volume relationship curves of the foam oil gas system under intermittent cold production conditions with a shutdown duration of 10 hours. As shown in Figure 5, the dots indicate the system pressure and volume values ​​read during the experiment; the horizontal axis represents the pressure of the foam oil gas system under intermittent cold production conditions, in MPa; and the vertical axis represents the volume of the foam oil gas system under intermittent cold production conditions, in ml.

[0115] Figure 6 shows the pressure drop rate of 1 MPa·h provided in the embodiment of this application. -1 Figure 6 shows a schematic diagram of the pressure and volume relationship curves of the foam oil gas system under intermittent cold production conditions with a shutdown duration of 20 hours. As shown in Figure 6, the dots indicate the system pressure and volume values ​​read during the experiment; the horizontal axis represents the pressure of the foam oil gas system under intermittent cold production conditions, in MPa; and the vertical axis represents the volume of the foam oil gas system under intermittent cold production conditions, in ml.

[0116] Figure 7 shows the pressure drop rate of 2 MPa·h provided in the embodiment of this application. -1 Figure 7 shows a schematic diagram of the pressure-volume relationship curves of the foamed oil gas system under intermittent cold extraction production conditions with a shutdown duration of 5 hours. As shown in Figure 7, the dots indicate a pressure drop rate of 1 MPa·h. -1The system pressure and volume values ​​were read during the experiment; the triangle was used to indicate a pressure drop rate of 2 MPa·h. -1 The system pressure and volume values ​​read during the experiment; the horizontal axis represents the pressure of the foam oil gas system under intermittent cold production conditions, in MPa; the vertical axis represents the volume of the foam oil gas system under intermittent cold production conditions, in ml.

[0117] Figure 8 shows the pressure drop rate of 2 MPa·h provided in the embodiment of this application. -1 Figure 8 shows a schematic diagram of the pressure-volume relationship curves of the foamed oil gas system under intermittent cold extraction production conditions with a shutdown duration of 10 hours. As shown in Figure 8, the dots indicate a pressure drop rate of 1 MPa·h. -1 The system pressure and volume values ​​were read during the experiment; the triangle was used to indicate a pressure drop rate of 2 MPa·h. -1 The system pressure and volume values ​​read during the experiment; the horizontal axis represents the pressure of the foam oil gas system under intermittent cold production conditions, in MPa; the vertical axis represents the volume of the foam oil gas system under intermittent cold production conditions, in ml.

[0118] Figure 9 shows the pressure drop rate of 2 MPa·h provided in the embodiment of this application. -1 Figure 9 shows a schematic diagram of the pressure-volume relationship curves of the foamed oil gas system under intermittent cold extraction production conditions with a shutdown duration of 10 hours. As shown in Figure 9, the dots indicate a pressure drop rate of 1 MPa·h. -1 The system pressure and volume values ​​were read during the experiment; the triangle was used to indicate a pressure drop rate of 2 MPa·h. -1 The system pressure and volume values ​​read during the experiment; the horizontal axis represents the pressure of the foam oil gas system under intermittent cold production conditions, in MPa; the vertical axis represents the volume of the foam oil gas system under intermittent cold production conditions, in ml.

[0119] As shown in Figures 4 to 9 above, with the increase of pressure drop rate and the length of shutdown time, the slope of the system pressure-volume relationship curve (foam oil flow stage) under different shutdown durations and pressure drop rates gradually decreases, and the foam oil phenomenon weakens.

[0120] S102. Based on the experimental data, establish the first model and the second model.

[0121] Among them, the first model is the calculation model of the pseudo-bubble point pressure of foam oil under the condition of intermittent cold production of foam oil, and the second model is the relationship model between the pressure and volume of the oil and gas system of foam oil under the condition of intermittent cold production of foam oil.

[0122] In this embodiment, the experimental data includes the foaming point pressure of the foamed oil and the pressure-volume relationship curves of the system under different shutdown durations and pressure drop rates. The first model established based on the experimental data is shown in Formula 1: P pb=2.125 + 0.0236t p -0.2333dp (1)

[0123] Among them, P pb The pressure is the simulated bubble point pressure, in MPa; t p The shutdown duration is expressed in hours (h); dp is the pressure drop rate, expressed in MPa·h. -1 .

[0124] By fitting experimental data, a second model was established and divided into four stages, corresponding to the initial depressurization production (single-phase flow) stage, the initial depressurization production (foamed oil flow) stage, the shutdown stage, and the production recovery stage.

[0125] Specifically, in the initial depressurization production (single-phase flow) stage (from the initial reservoir pressure to the bubble point pressure), only a single oil phase exists, so a quadratic equation is used for fitting. In the initial depressurization production (foam oil flow) stage (from the bubble point pressure to the shutdown pressure), gas begins to precipitate, and as the foam oil pressure decreases, the volume increases at an accelerated rate, so a quadratic equation is used for fitting. In the shutdown stage, the volume of foam oil does not change with pressure. In the production recovery stage (from the pressure corresponding to the resumption of production to the reservoir abandonment pressure), a small amount of free gas is generated, and new foam oil is generated. As the foam oil pressure continues to decrease, the volume increases at an accelerated rate, forming an oil-gas two-phase flow, which is fitted using a quartic equation.

[0126] Based on the experimental data, the first model established is shown in the following formula (2):

[0127] Where V(t) is the total volume of the system, in cm³. 3 V(t) s ( ) represents the total volume of the system at the start of shutdown, in cm³. 3 P represents the system pressure, measured in MPa.

[0128] Parameters A, B, C, D, and E are shown in the following formulas (3)-(7): A = -1.228 + 0.2533t p +1.632dp - 0.01068t p 2 -0.009154t p ×dp (3) B=-7.192+3.02t p +16.31dp-0.1364t p 2 +0.09781t p ×dp (4) C=9.793+13.38t p +55.26dp - 0.6237t p 2+1.222t p ×dp (5) D=121.7+27.68t p +69dp-1.212t p 2 +3.063t p ×dp (6) E=341.6+25.59t p +16.6dp-0.8635t p 2 +1.216t p ×dp (7)

[0129] Among them, t p The shutdown duration is expressed in hours (h); dp is the pressure drop rate, expressed in MPa·h. -1 .

[0130] In one possible implementation, in order to verify the reliability of the first model and the second model, the calculation results of the first model and the second model are compared with the experimental results, and the error is calculated. If the error is less than the error threshold, the reliability of the first model and the second model is guaranteed.

[0131] In this embodiment of the application, the error threshold is 1%, and the calculation results and experimental results of the first model and the second model are shown in Figures 10 and 11.

[0132] Figure 10 shows the pressure drop rate of 1 MPa·h provided in the embodiment of this application. -1 Figure 10 shows a comparison between experimental and calculated results of the pressure and volume relationship curves of the foam oil gas system under intermittent cold recovery production conditions with different shutdown times. As shown in Figure 10, triangles indicate experimental results for a shutdown time of 5 hours, and the corresponding curves indicate calculated results for the same shutdown time; rhombuses indicate experimental results for a shutdown time of 10 hours, and the corresponding curves indicate calculated results for the same shutdown time; circles indicate experimental results for a shutdown time of 20 hours, and the corresponding curves indicate calculated results for the same shutdown time. The horizontal axis represents the pressure of the foam oil gas system under intermittent cold recovery production conditions, in MPa; the vertical axis represents the volume of the foam oil gas system under intermittent cold recovery production conditions, in ml.

[0133] Figure 11 shows the pressure drop rate of 2 MPa·h provided in the embodiment of this application. -1Figure 11 shows a comparison between experimental and calculated results of the pressure and volume relationship curves of the foam oil gas system under intermittent cold recovery production conditions with different shutdown times. As shown in Figure 11, triangles indicate experimental results for a shutdown time of 5 hours, and the corresponding curves indicate calculated results for the same shutdown time; rhombuses indicate experimental results for a shutdown time of 10 hours, and the corresponding curves indicate calculated results for the same shutdown time; circles indicate experimental results for a shutdown time of 20 hours, and the corresponding curves indicate calculated results for the same shutdown time. The horizontal axis represents the pressure of the foam oil gas system under intermittent cold recovery production conditions, in MPa; the vertical axis represents the volume of the foam oil gas system under intermittent cold recovery production conditions, in ml.

[0134] As shown in Figures 10 and 11, the fitting error of the expansion experiment results of foam oil and other components under intermittent cold production conditions is 0.14%, which is less than the error threshold of 1%, ensuring the reliability of the foam oil pseudo-bubble point pressure calculation model and the foam oil pressure-volume relationship model under intermittent cold production conditions.

[0135] S103. Based on the first model and the second model, obtain the relationship curves between the foam oil pseudo-foaming point pressure, system pressure and volume under the condition of intermittent cold production foam oil.

[0136] Specifically, based on the first and second models, the relationship curves between the foam oil's pseudo-foaming point pressure, system pressure, and volume under intermittent cold-production foam oil conditions are shown in the following formula (8):

[0137] Where V(t) is the system volume under intermittent cold extraction production conditions, in m³. 3 ;n em The amount of gas released under equilibrium conditions is expressed in mol; t pb The development time for the pressure to drop to the pseudo-bubble point pressure, in minutes (t). em The time for the foamed oil to reach equilibrium is given in minutes; m1 and m2 are the bubble growth coefficients during the foamed oil flow and the oil-gas two-phase flow process; Z is the gas compressibility factor; R is the molar gas constant 8.31, in J / (mol·K); T is the reservoir temperature, in K; P i P(t) is the initial pressure, in MPa; P(t) is the pressure at time t, in MPa; V o1 This represents the initial oil phase volume, in cubic meters (m³). 3 C o This refers to the compressibility coefficient of crude oil, measured in MPa. -1 .

[0138] S104. Based on the relationship curves of the foam oil's pseudo-foaming point pressure, system pressure, and volume, determine the high-pressure physical property parameters of the foam oil under intermittent cold production conditions.

[0139] Among them, the high-pressure physical properties of foam oil under intermittent cold production conditions include at least one of the following: foam oil volume index, foam oil dissolved gas-oil ratio, or foam oil viscosity.

[0140] Specifically, based on the relationship curves between the bubble point pressure, system pressure, and volume of foam oil, the volume coefficient of foam oil is calculated based on the volume of foam oil, the volume of dead oil under standard conditions, the volume of dispersed gas, and the volume of the oil phase; the dissolved gas-oil ratio of foam oil is calculated based on the free gas volume, the initial dissolved gas volume, the total volume of the gas system, the volume of foam oil, and the molar volume of the precipitated gas; and the viscosity of foam oil is calculated based on the dead oil viscosity, the viscosity coefficient of foam oil, the gas system pressure, the bubble point pressure, the initial dissolved gas-oil ratio, and the dissolved gas-oil ratio of foam oil.

[0141] The method for determining the high-pressure physical properties of foamed oil provided in this application involves acquiring experimental data from a simulation experiment of intermittent cold-production foamed oil; establishing a first model and a second model based on the experimental data; then, based on the first model and the second model, obtaining the relationship curves between the simulated bubble point pressure, system pressure, and volume of the foamed oil under the intermittent cold-production foamed oil condition; finally, determining the high-pressure physical properties of the foamed oil under the intermittent cold-production foamed oil condition based on the relationship curves. In this application embodiment, the high-pressure physical properties of foamed oil under the intermittent cold-production production condition can be accurately determined.

[0142] Figure 12 is a schematic flowchart (II) of a method for determining the high-pressure physical property parameters of foamed oil according to an embodiment of this application. As shown in Figure 12, the method includes the following steps:

[0143] S1201. Obtain experimental data from a simulation experiment of intermittent cold-extraction foam oil.

[0144] S1202. Based on the experimental data, establish the first model and the second model.

[0145] S1203. Based on the first model and the second model, obtain the relationship curves between the foam oil pseudo-foaming point pressure, system pressure and volume under the condition of intermittent cold production foam oil.

[0146] It should be noted that the specific implementation steps of S1201, S1202, and S1203 can be referred to the specific implementation steps of S101, S102, and S103 mentioned above, and will not be repeated here.

[0147] S1204. Based on the relationship curve between the foam oil's pseudo-foaming point pressure, system pressure, and volume, obtain the volume of the foam oil gas system under intermittent cold production conditions.

[0148] In one possible implementation, the amount of gas released, a first coefficient, a second coefficient, and the time it takes for the foamed oil to reach equilibrium are obtained based on the relationship curve. The first and second coefficients are the bubble growth coefficients during the foamed oil flow and the oil-gas two-phase flow process.

[0149] The volume of the foam oil gas system under intermittent cold production conditions is obtained based on the amount of gas released, the first coefficient, the second coefficient, and the time it takes for the foam oil to reach equilibrium.

[0150] Specifically, as shown in formula (8), the relationship curve between the foam oil's pseudo-foaming point pressure, system pressure, and volume indicates that the amount of gas released under equilibrium conditions is n. em The unit is mol; the time for foamed oil to reach equilibrium is t. em The unit is min; the bubble growth coefficients in the foamed oil flow and oil-gas two-phase flow processes are the first coefficient m1 and the second coefficient m2.

[0151] Based on the relationship curve, the amount of gas produced, the first coefficient, the second coefficient, and the time it takes for the foam oil to reach equilibrium, the volume of the foam oil gas system under intermittent cold production conditions is obtained.

[0152] In one possible implementation, the molar volume of the evolved gas, the total volume of the foam oil in equilibrium at the current pressure, and the oil phase volume of the foam oil in equilibrium at the current pressure are obtained based on the relationship curve between the foam oil's pseudo-bubbling point pressure, the system pressure, and the volume. The amount of evolved gas in equilibrium is then obtained based on the molar volume of the evolved gas, the total volume of the foam oil in equilibrium at the current pressure, and the oil phase volume of the foam oil in equilibrium at the current pressure.

[0153] Specifically, based on the relationship curve between the foaming point pressure of the foaming oil, the system pressure, and the volume, the molar volume V of the evolved gas is obtained. M The total volume V of the foamed oil in equilibrium state under the current pressure em (t) The volume of the oil phase in the foam oil equilibrium state under the current pressure, V o (t).

[0154] In this embodiment, the molar volume V of the gas released under different system pressures is obtained based on the relationship curve between the foaming point pressure of the foam oil, the system pressure, and the volume. M As shown in Table 2; the total volume V of the foamed oil equilibrium state under different system pressures was obtained. em (t) As shown in Table 3; Obtain the oil phase volume V of the foam oil equilibrium state under different system pressures. o (t) is shown in Table 4:

[0155] Table 2

[0156] Table 3

[0157] Table 4

[0158] Based on the molar volume V of the evolved gas M The total volume V of the foamed oil in equilibrium state under the current pressure em (t) The volume of the oil phase in the foam oil equilibrium state under the current pressure, V o (t), to obtain the amount of gas released under equilibrium conditions, n. em As shown in the following formula (9):

[0159] Where, n em V represents the amount of gas released under equilibrium conditions, expressed in kmol; em (t) represents the total volume of the foamed oil in equilibrium under the current pressure, in cubic meters. 3 V o (t) represents the volume of the oil phase in equilibrium under the current pressure, in cubic meters. 3 V M The molar volume of the gas being evolved is expressed in m³. 3 ·kmol -1 .

[0160] In the implementation of this application, based on the molar volume V of the evolved gas... M The total volume V of the foamed oil in equilibrium state under the current pressure em (t) The volume of the oil phase in the foam oil equilibrium state under the current pressure, V o (t), to obtain the amount of gas released under equilibrium conditions, n. em As shown in Table 5:

[0161] Table 5

[0162] In one possible implementation, the attraction coefficient 'a' and critical property constant 'b' of the gas system are obtained based on the relationship curve between the foaming point pressure of the foam oil, the system pressure, and the volume.

[0163] Based on the attraction coefficient a and the critical property constant b, the molar volume V of the evolved gas is obtained. M As shown in the following formula (10):

[0164] Where P is the system pressure in kPa; R is the molar gas constant of 8.31 J / (mol·K); T is the reservoir temperature in K; a is the attraction coefficient, dimensionless; and b is the critical property constant in m³. 3 ·kmol -1 V M The molar volume of the evolved gas is expressed in m³.3 ·kmol -1 .

[0165] In this embodiment of the application, formula (11) is obtained by rearranging formula (10), and the molar volume V of the evolved gas is obtained by calculating formula (11) using Newton's iteration method. M As shown in the following formula (11): PV M 3 +(bP-RT)V M 2 +(a-3b 2 P-2bRT)V M +b 3 P+RTb 2 -ab=0 (11)

[0166] Where P is the system pressure in kPa; R is the molar gas constant of 8.31 J / (mol·K); T is the reservoir temperature in K; a is the attraction coefficient, dimensionless; and b is the critical property constant in m³. 3 ·kmol -1 V M The molar volume of the evolved gas is expressed in m³. 3 ·kmol -1 .

[0167] In one possible implementation, the relative temperature is obtained based on the relationship curve between the foaming point pressure of the foam oil, the system pressure, and the volume; and the attraction coefficient and critical property constant of each gas in the gas system are obtained based on the relative temperature and the critical temperature.

[0168] Specifically, based on the relationship curve between the foaming point pressure of the foaming oil, the system pressure, and the volume, the relative temperature T is obtained. r According to relative temperature T r The coefficient α is calculated using formula (12), as shown in the following formula (12):

[0169] Where α is a dimensionless coefficient; ω is an eccentricity factor, which is dimensionless; T r The value is a relative temperature, dimensionless.

[0170] In this embodiment, the eccentricity factor ω for heavy oil, methane, and carbon dioxide is 1.1941, 0.0080, and 0.2238, respectively; based on the relationship curve between the pseudo-foaming point pressure of the foaming oil, the system pressure, and the volume, the relative temperatures T of heavy oil, methane, and carbon dioxide are obtained. r The values ​​are 0.3407, 1.7179, and 1.0762; the dimensionless coefficients α for heavy oil, methane, and carbon dioxide are 3.1064, 0.7740, and 0.9478, respectively.

[0171] Based on the coefficient α, the attraction coefficient a and critical property constant b corresponding to each gas in the gas system are obtained, as shown in the following formulas (13) and (14): a=a c α(T r ,ω) (13)

[0172] Where a is the attraction coefficient, which is dimensionless; a c is the critical attraction coefficient, dimensionless; b is the critical property constant, in units of m. 3 ·kmol -1 R is the molar gas constant, 8.31, in J / (mol·K); T c Critical temperature, unit: K; P c ρ is the critical pressure, kPa; w is the eccentricity factor of the gas.

[0173] Optionally, the critical attraction coefficient a can be calculated using the following formula (15). c :

[0174] Among them, a c The critical attraction coefficient is dimensionless; R is the molar gas constant 8.31, in J / (mol·K); T c Critical temperature, unit: K; P c This is the critical pressure.

[0175] Based on the attraction coefficient and critical property constant of each gas, the attraction coefficient and critical property constant of the gas system are obtained.

[0176] It is possible that in actual production processes, the released gas is a mixture, which may include natural gas. This mixture may contain multiple gases, such as methane and carbon dioxide. In this case, it is necessary to obtain the attraction coefficient and critical property constant for each gas, and based on these parameters, to obtain the attraction coefficient and critical property constant for the gas system.

[0177] The attraction coefficient a and critical property constant b of the gas system are obtained using the following formulas (16) and (17):

[0178] Among them, a i a j ... i Let m be the critical property constant of component i, in units of m. 3 ·kmol -1 ;δ ijx is the dimensionless interaction parameter between component i and component j; i x j Let i be the mole fraction of component i and j in the system, n be the fraction of the evolved gas; a be the system attraction coefficient, dimensionless; b be the critical property constant of the system, in units of m. 3 ·kmol -1 .

[0179] In the embodiments of this application, the critical pressure P of heavy oil, methane, and carbon dioxide is... c The pressures are 945.86 kPa, 4600 kPa, and 7378 kPa, respectively; the number of components in the evolved gas, n, is 3; the interaction parameter δ between component i and component j is... ij As shown in Table 6, the mole fractions x of heavy oil, methane, and carbon dioxide in the system are 0.6610, 0.2945, and 0.0445, respectively; the calculated attraction coefficients a of heavy oil, methane, and carbon dioxide components are... i The critical property constants b for heavy oil, methane, and carbon dioxide components are 101.3341, 0.04197, and 0.05091, respectively. i It is 0.6544m 3 ·kmol -1 0.0268m 3 ·kmol -1 0.0267m 3 ·kmol -1 a is 0.8625; b is 0.4416.

[0180] Table 6

[0181] In one possible implementation, the critical temperature and reservoir temperature are obtained based on the relationship curve between the foam oil's pseudo-foaming point pressure, system pressure, and volume; and the relative temperature is obtained based on the critical temperature and reservoir temperature.

[0182] Specifically, the critical temperature T is obtained based on the relationship curve between the foaming point pressure of the foaming oil, the system pressure, and the volume. c And reservoir temperature T; based on the critical temperature and reservoir temperature, the relative temperature T is obtained by the following formula (18). r :

[0183] Among them, T r Relative temperature, dimensionless; T is reservoir temperature, unit is K; T c This is the critical temperature, expressed in Kelvin (K).

[0184] In one possible implementation, the time it takes for the first coefficient, the second coefficient, and the foam oil to reach equilibrium is determined using a particle swarm optimization algorithm, including the following steps:

[0185] Step 1: Determine the objective function.

[0186] By minimizing the error O(V) between the calculated foam oil volume under intermittent cold production conditions obtained from formula (11) and the experimental data, m1, m2, and t are determined. em Therefore, O(V) is the objective function of the particle swarm optimization algorithm, as shown in the following formula (19):

[0187] Where n is the number of experimental records for foam oil under intermittent cold production conditions; total is the total number of experimental times for foam oil under intermittent cold production conditions; V(t) m V(t) represents the experimental value of foamed oil volume under intermittent cold production conditions at time t, in mL. cal This represents the calculated volume of foamed oil under intermittent cold production conditions at time t, in mL.

[0188] In this embodiment, the number of points n recorded in the foam oil experiment under intermittent cold production conditions is 39; the total number of time points recorded in the foam oil experiment under intermittent cold production conditions is 39; the experimental value V(1) of the volume of the foam oil gas system corresponding to different system pressures in the first iteration is... m As shown in Table 7; the calculated value of foam oil volume V(1) under the intermittent cold production state corresponding to different system pressures in the first iteration. cal As shown in Table 8.

[0189] Table 7

[0190] Table 8

[0191] Step 2: Initialize the population.

[0192] First, set the number of particles in the population to N, and the position and velocity of particle i as shown in the following formula (20):

[0193] Where, N is the number of particles in the population; Let t be the position of the i-th particle at time t; The velocity of the i-th particle at time t; Let m1, m2, and t be the positions of the i-th particle at time t. em The value is randomly selected from a range of possible values; Let be the velocity of the i-th particle in each direction at time t, and let be a random value between 0 and 1.

[0194] In this embodiment of the application, the number of particles N in the population is 30, the position of the i-th particle at time t=1 is shown in Table 9, and the initial velocities of the i-th particle in each direction at time t=1 are shown in Table 10.

[0195] Table 9

[0196] Table 10

[0197] Step 3: Calculate the velocity of the i-th particle in each direction at time t+1.

[0198] The velocities of the i-th particle at time t+1 are calculated by the following formula (21):

[0199] in, Let be the optimal position of all particles at time t; c1 represents the current optimal position; c2 represents the individual learning coefficient; c2 represents the social learning coefficient; r1 and r2 are random numbers between 0 and 1. Let be the velocity of the i-th particle at time t+1.

[0200] In this embodiment of the application, the optimal position (p) of the individual discovered in the first iteration i1 (t),p i2 (t),p i3 (t) is (2672.04801276, 0.02565394, 288.07627147); the currently discovered global optimal position P gk (t) is P ik (t); Individual learning coefficient c1 is 2; Social learning coefficient c2 is 2; r1 is 0.35, r2 is 0.40; Velocity of the i-th particle at time t+1. As shown in Table 11:

[0201] Table 11

[0202] Step 4: Calculate the position of the i-th particle at time t+1.

[0203] The method for calculating the position of the i-th particle at time t+1 is shown in the following formulas (22) and (23):

[0204] in, Let t be the position of the i-th particle at time t; Let be the position of the i-th particle at time t+1; Let be the velocity of the i-th particle at time t+1; Let be the objective function value corresponding to the position of the i-th particle at time t; Let be the objective function value corresponding to the position of the i-th particle at time t+1.

[0205] In this embodiment, the objective function value corresponding to the position of the i-th particle at time t=1 is... See Table 12; the objective function value corresponding to the position of the i-th particle at time t=2. See Table 13; Position of the i-th particle at time t=2 See Table 14.

[0206] Table 12

[0207] Table 13

[0208] Table 14

[0209] After the particle's position is updated, the objective function is calculated. If the objective function value is less than the objective function value at time t, it indicates that the new position is relatively better, and the position is updated at this time; otherwise, the position is not updated.

[0210] Step 5: Determine m1, m2, and t em value.

[0211] The calculation ends when the value of the objective function is less than the set allowable error of 1%, and the objective function value is determined to be m1, m2, and t. em The optimal value.

[0212] In this embodiment of the application, the calculation ends when the error is 0.95%, and the result is determined to be (2.8829 × 10⁻⁶). -6 7.4778×10 -5 (291.4823) are adjustable parameters m1, m2 and t em The optimal value.

[0213] S1205. Obtain high-pressure physical property parameters based on the volume of the oil and gas system.

[0214] Among them, the high-pressure physical property parameters include at least one of the following: foam oil volume factor, foam oil dissolved gas-oil ratio, or foam oil viscosity.

[0215] In one possible implementation, the high-pressure physical property parameter is obtained as the foam oil volume coefficient based on the volume of the oil and gas system.

[0216] Specifically, the foam oil volume factor is calculated based on the foam oil volume, the dead oil volume under standard conditions, the dispersed gas volume, and the oil phase volume, as shown in the following formulas (24) and (25):

[0217] V fo =V dis +V o (25)

[0218] Among them, B fo V is the volume coefficient of foamed oil, dimensionless; fo This refers to the volume of foamed oil, in meters (m). 3 V d This refers to the dead oil volume under standard conditions, in cubic meters (m³). 3 V dis The volume of dispersed gas is expressed in m³. 3 V o This is the volume of the oil phase, in cubic meters (m³). 3 .

[0219] Possibly, under different pressures, the ratio of dispersed gas to evolved gas in foamed oil is equal to the gas trapping coefficient α. g α g The calculation formula is shown in formula (26) below:

[0220] Where, α g P is the gas trapping coefficient, dimensionless; sc Atmospheric pressure, MPa; P pb P represents the simulated bubble point pressure in MPa; P is the current pressure of the foamed oil-gas system.

[0221] Possibly, the dispersed gas volume V dis Calculated using the following formula (27): V dis =n ev ×α g ×V M (27)

[0222] Among them, V diss For the volume of dispersed gas, m 3 ;n ev The amount of gas released is expressed in mol; α g V is the gas trapping coefficient, dimensionless; M m is the molar volume of the evolved gas. 3 .

[0223] In this embodiment of the application, the simulated bubble point pressure P pb 2 MPa; atmospheric pressure P sc The pressure is 0.101 MPa; the molar volume of the evolved gas is V. MAs shown in Table 2 above; the oil phase volume Vo is as shown above; the amount of gas released n ev As shown in Table 15; Dead oil volume V under standard conditions d It is 152.4460cm 3 The calculated gas trapping coefficient α at various pressures g As shown in Table 16; Dispersed gas volume V dis The calculation results are shown in Table 17; foam oil volume V fo As shown in Table 18; Foaming oil volume coefficient B fo The pressure correspondence is shown in Table 19.

[0224] Table 15

[0225] Table 16

[0226] Table 17

[0227] Table 18

[0228] Table 19

[0229] In one possible implementation, the high-pressure physical property parameter, the foam oil dissolved gas-oil ratio, is obtained based on the volume of the oil-gas system.

[0230] Specifically, the dissolved gas-oil ratio of foam oil is calculated based on the free gas volume, the initial dissolved gas volume, the total volume of the gas system, the volume of foam oil, and the molar volume of the precipitated gas, as shown in the following formulas (28) and (29):

[0231] Among them, R sfo The oil-to-gas ratio in foam oil is expressed in m³. 3 ·m -3 ;n free n represents the amount of free gas at a certain pressure, expressed in mol. al V represents the initial dissolved gas volume, expressed in mol. d This refers to the dead oil volume under standard conditions, in cubic meters (m³). 3 V(t) is the total volume of the system, in cubic meters. 3 V fo This refers to the volume of foamed oil, in meters (m). 3 V M The molar volume of the evolved gas is expressed in m³. 3 ·kmol -1 .

[0232] In this embodiment, the free gas volume n under a certain pressure freeAs shown in Table 20; initial dissolved gas volume n al It is 0.298 mol; the volume of dead oil under standard conditions, V d It is 152.4460cm 3 The total system volume V(t) is shown in Table 7; the calculated foam oil dissolved gas-oil ratio R sfo As shown in Table 21.

[0233] Table 20

[0234] Table 21

[0235] In one possible implementation, the high-pressure physical property parameter, foam oil viscosity, is obtained based on the volume of the oil-gas system.

[0236] Specifically, the viscosity of foam oil is calculated based on the dead oil viscosity, viscosity coefficient, gas system pressure, bubble point pressure, original dissolved gas-oil ratio, and dissolved gas-oil ratio of foam oil, as shown in the following formula (30):

[0237] Where, μ fo The viscosity of the foamed oil is expressed in mPa·s; μ o K is the dead viscosity of the foamed oil, in mPa·s; k1 and k2 are the viscosity coefficients of the foamed oil, dimensionless; P is the system pressure, in MPa. p R is the bubble point pressure, in MPa. si The original dissolved gas-oil ratio, in m³. 3 ·m -3 ;R sfo The oil-to-gas ratio in foam oil is expressed in m³. 3 ·m -3 .

[0238] In this embodiment of the application, the viscosity μ of the foamed oil is... o The viscosity coefficient of the foaming oil is 11854 mPa·s; the viscosity coefficients k1 and k2 are 0.43 and 0.52, respectively; the bubble point pressure P... p 4.15 MPa; R si The original dissolved gas-oil ratio was 8.65m. 3 ·m -3 Foam oil dissolves gas-oil ratio R sfo As shown in Table 21; the calculated viscosity μ of the foam oil fo The calculation results are shown in Table 22:

[0239] Table 22

[0240] The method for determining the high-pressure physical properties of foamed oil provided in this application involves acquiring experimental data from a simulation experiment of intermittent cold-production foamed oil; establishing a first model and a second model based on the experimental data; then, based on the first model and the second model, obtaining the relationship curves between the simulated bubble point pressure, system pressure, and volume of the foamed oil under intermittent cold-production conditions; and obtaining the volume of the foamed oil gas system under intermittent cold-production conditions based on the relationship curves. Based on the volume of the gas system, the high-pressure physical properties are obtained. In this application embodiment, the high-pressure physical properties of foamed oil under intermittent cold-production conditions can be accurately determined.

[0241] Figure 13 is a structural schematic diagram of a high-pressure physical property parameter determination device for foamed oil provided in this application. As shown in Figure 13, the high-pressure physical property parameter determination device 1300 for foamed oil provided in this embodiment includes:

[0242] The acquisition module 1301 is used to acquire experimental data from the simulation experiment of intermittent cold-harvested foam oil.

[0243] The processing module 1302 is used to establish a first model and a second model based on experimental data. The first model is a calculation model of the pseudo-bubble point pressure of foam oil under intermittent cold production foam oil conditions, and the second model is a model of the relationship between pressure and volume of the oil-gas system of foam oil under intermittent cold production foam oil conditions.

[0244] The processing module 1302 is also used to obtain the relationship curves between the foam oil pseudo-foaming point pressure, system pressure and volume under the state of intermittent cold-extracted foam oil, based on the first model and the second model.

[0245] The determination module 1303 is used to determine the high-pressure physical property parameters of foam oil under intermittent cold extraction conditions based on the relationship curve.

[0246] In one possible implementation, the high-pressure physical properties of the foam oil under intermittent cold-harvested conditions are determined based on the relationship curve, including:

[0247] Based on the relationship curve, obtain the volume of the foamed oil-gas system under intermittent cold production conditions;

[0248] Based on the volume of the oil and gas system, high-pressure physical property parameters are obtained.

[0249] In one possible implementation, the high-pressure physical properties include at least one of the following:

[0250] Foam oil volume factor, foam oil dissolved gas-oil ratio, or foam oil viscosity.

[0251] In one possible implementation, the volume of the foamed oil-gas system under intermittent cold recovery production conditions is obtained based on the relationship curve, including:

[0252] Based on the relationship curve, the amount of gas released, the first coefficient, the second coefficient, and the time for the foam oil to reach equilibrium under equilibrium conditions are obtained. Among them, the first coefficient and the second coefficient are the bubble growth coefficients in the foam oil flow and oil-gas two-phase flow processes.

[0253] The volume of the foam oil gas system under intermittent cold production conditions is obtained based on the amount of gas released, the first coefficient, the second coefficient, and the time it takes for the foam oil to reach equilibrium.

[0254] In one possible implementation, obtaining the amount of gas released in equilibrium based on the relationship curve includes: obtaining the molar volume of the gas released, the total volume of the foam oil in equilibrium at the current pressure, and the oil phase volume of the foam oil in equilibrium at the current pressure based on the relationship curve.

[0255] The amount of gas released under equilibrium conditions is obtained based on the molar volume of the gas released, the total volume of the foamed oil in equilibrium under the current pressure, and the volume of the oil phase in equilibrium under the current pressure.

[0256] In one possible implementation, obtaining the molar volume of the evolved gas based on the relationship curve includes:

[0257] Based on the relationship curve, obtain the attraction coefficient and critical property constant of the gas system;

[0258] The molar volume of the evolved gas is obtained based on the attraction coefficient and the critical property constant.

[0259] In one possible implementation, the gas system includes multiple gases;

[0260] Based on the relationship curve, obtain the attraction coefficient and critical property constants of the gas system, including:

[0261] Obtain the relative temperature based on the relationship curve;

[0262] Based on the relative temperature and critical temperature, obtain the attraction coefficient and critical property constant of each gas in the gas system;

[0263] Based on the attraction coefficients and critical property constants of each gas, the attraction coefficients and critical property constants of the gas system are obtained.

[0264] In one possible implementation, obtaining the relative temperature based on the relationship curve includes:

[0265] Based on the relationship curve, obtain the critical temperature and reservoir temperature;

[0266] The relative temperature is obtained based on the critical temperature and the reservoir temperature.

[0267] In one possible implementation, the time it takes for the first coefficient, the second coefficient, and the foam oil to reach equilibrium is determined using a particle swarm optimization algorithm.

[0268] In one possible implementation, the foam oil volume factor is calculated based on the foam oil volume, the dead oil volume under standard conditions, the dispersed gas volume, and the oil phase volume.

[0269] In one possible implementation, the foam oil-to-dissolved gas-oil ratio is calculated based on the free gas volume, the initial dissolved gas volume, the total volume of the gas system, the foam oil volume, and the molar volume of the precipitated gas.

[0270] In one possible implementation, the foam oil viscosity is calculated based on the dead oil viscosity of the foam oil, the foam oil viscosity coefficient, the gas system pressure, the bubble point pressure, the original dissolved gas-oil ratio, and the dissolved gas-oil ratio of the foam oil.

[0271] The high-pressure physical property parameter determination device for foamed oil provided in this embodiment can execute the method provided in the above method embodiment. Its implementation principle and technical effect are similar, and will not be described in detail here.

[0272] Figure 14 is a schematic diagram of the structure of an electronic device provided in this application. As shown in Figure 14, the electronic device 1400 provided in this embodiment includes at least one processor 1401 and a memory 1402. Optionally, the electronic device 1400 further includes a communication component 1403. The processor 1401, the memory 1402, and the communication component 1403 are connected via a bus 1404.

[0273] In the specific implementation process, at least one processor 1401 executes the computer execution instructions stored in the memory 1402, causing at least one processor 1401 to perform the above-described method. The specific implementation process of the processor 1401 can be found in the above-described method embodiments, and its implementation principle and technical effects are similar, so it will not be repeated here.

[0274] In the above embodiments, it should be understood that the processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), etc. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in this invention can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules within the processor.

[0275] The memory may include random access memory (RAM) and may also include non-volatile memory (NVM), such as at least one disk storage device.

[0276] The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc. For ease of illustration, the buses shown in the accompanying drawings are not limited to a single bus or a single type of bus.

[0277] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the above-described method. This application also provides a computer-readable storage medium storing computer-executable instructions that, when executed by a processor, implement the above-described method.

[0278] The aforementioned readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The readable storage medium can be any available medium accessible to a general-purpose or special-purpose computer.

[0279] An exemplary readable storage medium is coupled to a processor, enabling the processor to read information from and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can reside in an Application Specific Integrated Circuit (ASIC). Alternatively, the processor and the readable storage medium can exist as discrete components in the device.

[0280] The division of units is merely a logical functional division; in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0281] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs. Furthermore, the functional units in the various embodiments of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0282] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0283] Those skilled in the art will understand that all or part of the steps of the above-described method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0284] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A method for determining high pressure physical property parameters of a foamy oil, characterized in that, include: Experimental data were obtained from a simulation experiment of intermittent cold-extraction foam oil. Based on the experimental data, a first model and a second model were established. The first model is a calculation model for the pseudo-bubble point pressure of foam oil under intermittent cold production conditions, and the second model is a model for the relationship between pressure and volume of the oil-gas system of foam oil under intermittent cold production conditions. Based on the first model and the second model, obtain the relationship curves between the foam oil's pseudo-foaming point pressure, system pressure, and volume under the condition of intermittent cold-extraction foam oil; Based on the relationship curve, the high-pressure physical properties of foam oil under intermittent cold extraction conditions are determined.

2. The method of claim 1, wherein, The step of determining the high-pressure physical properties of foam oil under intermittent cold-production conditions based on the relationship curve includes: Based on the relationship curve, the volume of the foamed oil-gas system under intermittent cold production conditions is obtained; The high-pressure physical property parameters are obtained based on the volume of the oil and gas system.

3. The method according to claim 1 or 2, characterized in that, The high-pressure physical property parameters include at least one of the following: Foam oil volume factor, foam oil dissolved gas-oil ratio, or foam oil viscosity.

4. The method according to claim 2, characterized in that, The step of obtaining the volume of the foamed oil-gas system under intermittent cold production conditions based on the relationship curve includes: Based on the relationship curve, the amount of gas released, the first coefficient, the second coefficient, and the time for the foam oil to reach equilibrium under equilibrium conditions are obtained. The first coefficient and the second coefficient are the bubble growth coefficients in the foam oil flow and oil-gas two-phase flow processes. Based on the amount of gas produced, the first coefficient, the second coefficient, and the time it takes for the foam oil to reach equilibrium, the volume of the foam oil gas system under intermittent cold production conditions is obtained.

5. The method of claim 4, wherein, The step of obtaining the amount of gas released under equilibrium conditions based on the relationship curve includes: Based on the relationship curve, obtain the molar volume of the evolved gas, the total volume of the foamed oil in equilibrium under the current pressure, and the oil phase volume of the foamed oil in equilibrium under the current pressure; The amount of gas released under equilibrium conditions is obtained based on the molar volume of the gas released, the total volume of the foamed oil in equilibrium under the current pressure, and the volume of the oil phase in equilibrium under the current pressure.

6. The method according to claim 5, characterized in that, Obtaining the molar volume of the evolved gas based on the relationship curve includes: Based on the relationship curve, the attraction coefficient and critical property constant of the gas system are obtained; The molar volume of the evolved gas is obtained based on the attraction coefficient and the critical property constant.

7. The method according to claim 6, characterized in that, The gas system includes a variety of gases; The step of obtaining the attraction coefficient and critical property constant of the gas system based on the relationship curve includes: The relative temperature is obtained based on the relationship curve. Based on the relative temperature and critical temperature, the attraction coefficient and critical property constant of each gas in the gas system are obtained; The attraction coefficient and critical property constant of the gas system are obtained based on the attraction coefficient and critical property constant of each gas.

8. The method according to claim 7, characterized in that, The step of obtaining the relative temperature based on the relationship curve includes: Based on the relationship curve, the critical temperature and reservoir temperature are obtained; The relative temperature is obtained based on the critical temperature and the reservoir temperature.

9. The method according to claim 4, characterized in that, The time it takes for the first coefficient, the second coefficient, and the foam oil to reach equilibrium is determined using a particle swarm optimization algorithm.

10. The method according to claim 3, characterized in that, The foam oil volume factor is calculated based on the foam oil volume, the dead oil volume under standard conditions, the dispersed gas volume, and the oil phase volume.

11. The method according to claim 3, characterized in that, The foam oil dissolved gas-oil ratio is calculated based on the free gas volume, the initial dissolved gas volume, the total volume of the gas system, the foam oil volume, and the molar volume of the precipitated gas.

12. The method according to claim 3, characterized in that, The viscosity of the foam oil is calculated based on the dead oil viscosity of the foam oil, the viscosity coefficient of the foam oil, the gas system pressure, the bubble point pressure, the original dissolved gas-oil ratio, and the dissolved gas-oil ratio of the foam oil.

13. A device for determining the high-pressure physical property parameters of foamed oil, characterized in that, include: The acquisition module is used to acquire experimental data from simulation experiments of intermittent cold-harvested foam oil. The processing module is used to establish a first model and a second model based on the experimental data. The first model is a calculation model of the pseudo-bubble point pressure of foam oil under intermittent cold production foam oil conditions, and the second model is a model of the relationship between pressure and volume of the oil-gas system of foam oil under intermittent cold production foam oil conditions. The processing module is further configured to obtain, based on the first model and the second model, the relationship curve between the foam oil's pseudo-foaming point pressure, system pressure, and volume under the condition of intermittent cold-extraction foam oil; The determination module is used to determine the high-pressure physical property parameters of foam oil under intermittent cold-extraction conditions based on the relationship curve.

14. An electronic device, characterized in that, include: Memory, processor; The memory stores computer-executed instructions; The processor executes computer execution instructions stored in the memory, causing the processor to perform the method as described in any one of claims 1-12.

15. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the method as described in any one of claims 1-12.

16. A computer program product comprising a computer program that, when executed by a processor, implements the method of any one of claims 1-12.

Images