Device and method for measuring diffusion coefficient of CO2 in crude oil

Abstract

The present invention provides a method for measuring CO 2 Apparatus and method for determining the diffusion coefficient of crude oil, comprising: CO 2 Supply component, crude oil supply component, diffusion reaction component and measurement component; the diffusion reaction component has a CO supply 2 The reaction chamber where the diffusion reaction with crude oil occurs, CO 2 The supply assembly and the crude oil supply assembly are connected to the reaction chamber of the reaction chamber through a multi-way valve, the reaction chamber is provided with at least one blind hole connected to the reaction chamber, and the reaction chamber has a partially light-transmitting side wall; the measuring assembly includes a pressure detection component arranged on the pipeline of the multi-way valve, a reaction recording component located outside the light-transmitting side wall of the reaction chamber, and a processing device electrically connected to the pressure detection component and the reaction recording component. The present invention can analyze CO 2 Diffusion process with crude oil under microscopic pore throat conditions and determination of CO 2 Diffusion coefficient in crude oil.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas acquisition engineering, and in particular to a device and method for measuring the diffusion coefficient of CO2 in crude oil. Background Art

[0002] The global warming problem caused by the massive emission of carbon dioxide is becoming increasingly serious. Using carbon dioxide to enhance oil recovery can not only achieve the storage effect of carbon dioxide, but also improve the recovery rate of crude oil in oil reservoirs. Therefore, carbon dioxide enhanced oil recovery technology is widely used in oil fields.

[0003] At present, in the process of using carbon dioxide for oil recovery, the mass transfer law of carbon dioxide in saturated crude oil cores is particularly important for predicting the migration characteristics of injected carbon dioxide. Therefore, the determination of the diffusion coefficient of carbon dioxide in saturated crude oil cores is of great significance for the development of carbon dioxide oil recovery technology. The EOR survey of the American "Oil and Gas Magazine" shows that carbon dioxide flooding has developed into the most effective EOR method besides thermal recovery. At present, the scale of carbon dioxide miscible flooding is large in the United States and Canada. At present, many coal-fired power plants and ethane to ethylene projects will emit a large amount of carbon dioxide tail gas. According to the survey, each ton of carbon dioxide injected can be exchanged for 0.25 to 0.45 tons of petroleum liquid. Using this batch of carbon dioxide to improve the recovery rate technology can increase the annual output by 40,000 to 60,000 tons. At present, the PVT (Pressure-Volume-Temperature) method is mostly used to measure the diffusion coefficient of carbon dioxide in crude oil. The measurement process mainly involves introducing carbon dioxide gas into the reactor containing crude oil, and calculating the diffusion coefficient of CO2 in crude oil by measuring various reaction parameters in the reactor.

[0004] However, in the above measurement process, the influence of porous media on the diffusion process is not involved. Therefore, the above measurement data cannot reflect the diffusion coefficient and diffusion process of CO2 and crude oil in porous media in the real formation, and has certain limitations. Summary of the invention

[0005] In order to solve at least one of the problems mentioned in the background technology, the present invention provides a device and method for determining the diffusion coefficient of CO2 in crude oil, which can analyze the diffusion process of CO2 with crude oil under microscopic pore throat conditions and determine the diffusion coefficient of CO2 in crude oil.

[0006] In order to achieve the above object, on the one hand, the present invention provides a device for measuring the diffusion coefficient of CO2 in crude oil, comprising:

[0007] CO2 supply components, crude oil supply components, diffusion reaction components and measurement components.

[0008] The diffusion reaction component has a reaction chamber for diffusion reaction of CO2 and crude oil. The CO2 supply component and the crude oil supply component are connected to the reaction chamber of the reaction chamber through a multi-way valve. At least one blind hole connected to the reaction chamber is provided in the reaction chamber, and the reaction chamber has a partially light-transmitting side wall.

[0009] The measuring component includes a pressure detecting component arranged on the pipeline of the multi-way valve, a reaction recording component located outside the light-transmitting side wall of the reaction chamber, and a processing device electrically connected to the pressure detecting component and the reaction recording component, the pressure detecting component is used to measure the reaction pressure in the reaction chamber, the reaction recording component is used to record the volume change of CO2 and the volume change of crude oil in the reaction chamber, and the processing device is used to determine the diffusion coefficient of CO2 in crude oil based on the reaction pressure, the volume of CO2 and the volume of crude oil.

[0010] In the above-mentioned device for measuring the diffusion coefficient of CO2 in crude oil, optionally, the diffusion reaction component also includes a light-transmitting shell, and the reaction chamber is placed in the shell to form an annular cavity between the inner wall of the shell and the outer wall of the reaction chamber.

[0011] The CO2 supply component and the crude oil supply component are connected to the feed port of the reaction chamber through a multi-way valve.

[0012] In the above-mentioned device for measuring the diffusion coefficient of CO2 in crude oil, optionally, the diffusion reaction component also includes a temperature control component.

[0013] The temperature adjustment unit comprises a heating cover and a temperature control device for controlling the heating temperature of the heating cover. The heating cover is surrounded by the outer periphery of the shell, and the heating cover is electrically connected to the temperature control device.

[0014] In the above-mentioned device for measuring the diffusion coefficient of CO2 in crude oil, optionally, the diffusion reaction component also includes a pressure regulator.

[0015] The annular chamber comprises a first annular chamber located above the reaction chamber and a second annular chamber located below the reaction chamber, and the first annular chamber and the second annular chamber are not connected to each other.

[0016] The pressure regulating component includes a first pressure pump and a second pressure pump. The output end of the first pressure pump is connected to the first annular cavity for regulating the flow of liquid entering the first annular cavity, thereby regulating the pressure value above the reaction chamber.

[0017] The output end of the second pressure pump is communicated with the second annular cavity, and is used to adjust the flow rate of the liquid entering the second annular cavity, thereby regulating the pressure value below the reaction chamber.

[0018] In the above-mentioned device for measuring the diffusion coefficient of CO2 in crude oil, optionally, the CO2 supply component includes a CO2 gas storage cylinder connected in sequence, a booster pump for increasing the CO2 circulation pressure, a drying tube for reducing the water content of the CO2 gas, a gas flow meter for detecting the CO2 gas circulation rate, and a one-way valve.

[0019] The flow direction of the one-way valve is toward the diffusion reaction component, and the output end of the one-way valve is communicated with one of the input ends of the multi-way valve.

[0020] In the above-mentioned device for measuring the diffusion coefficient of CO2 in crude oil, optionally, the crude oil supply component includes a horizontal flow pump and an intermediate container.

[0021] The intermediate container comprises a liquid inlet and a liquid outlet respectively arranged at two ends of the intermediate container, and a piston located inside the intermediate container, and the piston divides the inner cavity of the intermediate container into a first chamber and a second chamber which are not connected to each other.

[0022] The first chamber is communicated with the liquid inlet, and the second chamber is communicated with the liquid outlet.

[0023] The liquid outlet of the horizontal flow pump is communicated with the first chamber through the liquid inlet, and the second chamber is communicated with another input end of the multi-way valve through the liquid outlet.

[0024] The second chamber is used to contain crude oil, and the horizontal flow pump is used to pump liquid into the first chamber to push the piston to move toward the second chamber, so that the crude oil in the second chamber enters the reaction chamber through the liquid outlet and the multi-way valve.

[0025] In the above-mentioned device for measuring the diffusion coefficient of CO2 in crude oil, optionally, the device for measuring the diffusion coefficient of CO2 in crude oil also includes a waste liquid recovery device for recovering crude oil, and the waste liquid recovery device is connected to the discharge port of the reaction chamber.

[0026] In the above-mentioned device for measuring the diffusion coefficient of CO2 in crude oil, optionally, a pressure regulating valve is further connected between the waste liquid recovery device and the discharge port of the reaction chamber, and the pressure regulating valve is used to adjust the flow pressure of the discharge port of the reaction chamber.

[0027] In the above-mentioned device for measuring the diffusion coefficient of CO2 in crude oil, optionally, the device for measuring the diffusion coefficient of CO2 in crude oil also includes a light source component, which is arranged outside the shell, and the light emitting direction of the light source component is toward the reaction cavity of the reaction chamber.

[0028] In the above-mentioned device for measuring the diffusion coefficient of CO2 in crude oil, optionally, a sapphire glass sheet is provided between the shell and the reaction chamber.

[0029] On the other hand, the present invention also provides a method for measuring the diffusion coefficient of CO2 in crude oil, the method using the above-mentioned device for measuring the diffusion coefficient of CO2 in crude oil, the method for measuring the diffusion coefficient of CO2 in crude oil comprises the following steps:

[0030] CO2 and crude oil are pumped into the reaction chamber of the diffusion reaction component to allow CO2 to diffuse in the crude oil.

[0031] The reaction temperature in the reaction chamber, the volume of CO2 and crude oil in the reaction chamber, the flow pressure at the multi-way valve, the reaction time of the diffusion reaction, the flow rate of CO2 and the cross-sectional area of ​​the blind hole in the reaction chamber are detected.

[0032] The diffusion coefficient of CO2 in crude oil is determined based on the reaction temperature, reaction pressure, volume of CO2, volume of crude oil, flow pressure, reaction time, flow rate of CO2, and cross-sectional area of ​​the blind hole.

[0033] In the above method for determining the diffusion coefficient of CO2 in crude oil, optionally, the diffusion coefficient of CO2 in crude oil is determined according to the reaction temperature, reaction pressure, volume of CO2, volume of crude oil, flow pressure, reaction time, flow rate of CO2, and cross-sectional area of ​​the blind hole, specifically including:

[0034] According to the formula

[0035]

[0036] Determine the diffusion coefficient of CO2 in crude oil;

[0037] Where J represents the diffusion flux of CO2 in crude oil, and its unit is kg / (m 2 ·s); D represents the diffusion coefficient of CO2 in crude oil, in m 2 / s; A represents the cross-sectional area of ​​the blind hole; dt represents the reaction time; dm represents the flow rate of CO2 during the reaction time; is the concentration gradient of CO2 in crude oil.

[0038] The present invention provides a device and method for determining the diffusion coefficient of CO2 in crude oil. The device is provided with a diffusion reaction component for CO2 to undergo a diffusion reaction in crude oil, wherein at least one blind hole is provided in the reaction chamber of the diffusion reaction component for analyzing the influence of microscopic pore throat conditions on the diffusion of CO2 in crude oil, so as to simulate the diffusion process of CO2 in actual oil and gas reservoirs. By providing a temperature adjustment control and a pressure adjustment control in the diffusion reaction component, the reaction pressure and reaction temperature in the reaction chamber can be effectively and accurately regulated, and the influence of the reaction pressure and reaction temperature on the CO2 diffusion process can be analyzed. By providing a pressure detection component and a reaction recording component in the measurement component, the reaction pressure, the volume of CO2 and the volume of crude oil in the diffusion reaction process are obtained in real time to finally determine the diffusion coefficient of CO2 in crude oil. Therefore, the present invention can analyze the diffusion process of CO2 and crude oil under microscopic pore throat conditions and determine the diffusion coefficient of CO2 in crude oil, thereby improving the accuracy of the measurement of the diffusion coefficient of CO2 in crude oil.

[0039] The construction of the present invention and other objects and advantageous effects thereof will become more apparent through the description of the preferred embodiments in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0041] Figure 1 A schematic diagram of the structure of a device for measuring the diffusion coefficient of CO2 in crude oil provided in Example 1 of the present invention;

[0042] Figure 2 A schematic diagram of the structure of a CO2 supply assembly of an apparatus for measuring the diffusion coefficient of CO2 in crude oil provided in Embodiment 1 of the present invention;

[0043] Figure 3 A schematic diagram of the structure of a crude oil supply assembly of an apparatus for measuring the diffusion coefficient of CO2 in crude oil provided in Embodiment 1 of the present invention;

[0044] Figure 4 A schematic diagram of the structure of a diffusion reaction component of an apparatus for measuring the diffusion coefficient of CO2 in crude oil provided in Example 1 of the present invention;

[0045] Figure 5 A schematic diagram of a reaction chamber of a diffusion reaction assembly of a device for measuring the diffusion coefficient of CO2 in crude oil provided in the first embodiment of the present invention;

[0046] Figure 6 A schematic diagram of a reaction chamber of another structure of a diffusion reaction assembly of the device for measuring the diffusion coefficient of CO2 in crude oil provided in the first embodiment of the present invention;

[0047] Figure 7 A schematic flow chart of a method for determining the diffusion coefficient of CO2 in crude oil provided in Example 2 of the present invention.

[0048] Description of reference numerals:

[0049] 100-Device for determining the diffusion coefficient of CO2 in crude oil;

[0050] 10-CO2 supply assembly;

[0051] 11-CO2 gas cylinder;

[0052] 12-boosting pump;

[0053] 13- drying tube;

[0054] 14- Gas flow meter;

[0055] 15- one-way valve;

[0056] 20-Crude oil supply assembly;

[0057] 21-advection pump;

[0058] 22-intermediate container;

[0059] 221-piston;

[0060] 222-first chamber;

[0061] 223 - Second chamber;

[0062] 30-Diffusion reaction assembly;

[0063] 31- reaction chamber;

[0064] 311- reaction chamber;

[0065] 312-blind hole;

[0066] 32-Temperature adjustment control;

[0067] 321- Heating mantle;

[0068] 322-temperature control device;

[0069] 33-Pressure adjustment control

[0070] 331-first pressure pump;

[0071] 332-second pressure pump;

[0072] 34-housing;

[0073] 341 - first annular cavity;

[0074] 342 - second annular cavity;

[0075] 40- measurement assembly;

[0076] 41-pressure detection parts;

[0077] 42-Response recording component;

[0078] 50-Multi-way valve;

[0079] 60-waste liquid recovery device;

[0080] 70-pressure regulating valve;

[0081] 80-light source;

[0082] 90-Sapphire glass piece. DETAILED DESCRIPTION

[0083] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme in the embodiment of the present invention will be described in more detail below in conjunction with the drawings in the preferred embodiments of the present invention. In the drawings, the same or similar reference numerals throughout represent the same or similar parts or parts with the same or similar functions. The described embodiments are part of the embodiments of the present invention, not all of them. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limitations on the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. The embodiments of the present invention are described in detail below in conjunction with the drawings.

[0084] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, or it can be an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0085] Embodiment 1

[0086] Figure 1 This is a schematic diagram of the structure of a device for measuring the diffusion coefficient of CO2 in crude oil provided in Example 1 of the present invention. Figure 2 This is a schematic structural diagram of the CO2 supply component of the device for measuring the diffusion coefficient of CO2 in crude oil provided in Example 1 of the present invention. Figure 3 This is a schematic diagram of the structure of the crude oil supply component of the device for measuring the diffusion coefficient of CO2 in crude oil provided in Example 1 of the present invention. Figure 4 This is a schematic structural diagram of a diffusion reaction component of an apparatus for measuring the diffusion coefficient of CO2 in crude oil provided in Example 1 of the present invention. Figure 5 A schematic diagram of the structure of a reaction chamber of a diffusion reaction component of an apparatus for measuring the diffusion coefficient of CO2 in crude oil provided in Example 1 of the present invention. Figure 6 A schematic diagram of the structure of a reaction chamber of another structure of a diffusion reaction component of the device for measuring the diffusion coefficient of CO2 in crude oil provided in the first embodiment of the present invention.

[0087] See attached Figure 1 To Attachment Figure 6 As shown, the first embodiment of the present invention provides a device 100 for measuring the diffusion coefficient of CO2 in crude oil, comprising:

[0088] CO2 supply component 10, crude oil supply component 20, diffusion reaction component 30 and measurement component 40.

[0089] The diffusion reaction component 30 has a reaction chamber 31 for diffusion reaction of CO2 and crude oil. The CO2 supply component 10 and the crude oil supply component 20 are connected to the reaction chamber 311 of the reaction chamber 31 through a multi-way valve 50. At least one blind hole 312 connected to the reaction chamber 311 is provided in the reaction chamber 311, and the reaction chamber 31 has a partially light-transmitting side wall.

[0090] The measuring component 40 includes a pressure detecting component 41 arranged on the pipeline of the multi-way valve 50, a reaction recording component 42 located outside the light-transmitting side wall of the reaction chamber 31, and a processing device electrically connected to the pressure detecting component 41 and the reaction recording component 42. The pressure detecting component 41 is used to measure the reaction pressure in the reaction chamber 311, the reaction recording component 42 is used to record the volume change of CO2 and the volume change of crude oil in the reaction chamber 311, and the processing device is used to determine the diffusion coefficient of CO2 in crude oil based on the reaction pressure, the volume of CO2 and the volume of crude oil.

[0091] It should be noted that the reaction chamber 31 provided in this embodiment may be a closed chamber structure having a reaction cavity 311, and a feed port and a discharge port may be provided at both ends of the reaction chamber 31 for CO2 and crude oil to enter and flow out. At least one blind hole 312 may be provided inside the reaction chamber 31, as shown in FIG. Figure 5 and 6As shown, the blind hole 312 can be set as a square hole, a circular hole or a blind hole 312 of other shapes, and the size of the blind hole 312 is in the micron level. For example, when the blind hole 312 is a circular hole, the diameter of the circular hole and the depth of the blind hole 312 can be between several microns and tens of microns. In actual use, the shape and specific size of the blind hole 312 can be adjusted within the above range as needed. The specific shape and size of the blind hole 312 are not limited in this embodiment.

[0092] Further, part of the side wall of the reaction chamber 31 is light-transmissive. It can be understood that part of the side wall of the reaction chamber 31 is made of light-transmissive material, and the light-transmissive part and the light-impermeable part are integrally formed; or the reaction chamber 31 is made of light-transmissive material as a whole to ensure that it has a light-transmissive side wall. The reaction recording component 42 in the measurement component 40 can observe the CO2 diffusion reaction process in the reaction chamber 31 through the light-transmissive side wall of the reaction chamber 31 and record the volume changes of CO2 and crude oil during the diffusion reaction process.

[0093] The reaction recording component 42 may include at least a microscopic camera and a display electrically connected thereto, wherein the microscopic camera records the reaction process in the reaction chamber 31 and displays it on the display for viewing by the staff. The microscopic camera may be a camera with a magnification factor, wherein the specific magnification factor may be determined as required, in order to clearly observe the diffusion bubbles of CO2 in the crude oil and the bubble change process.

[0094] Further, see Attachment Figure 1 As shown, the CO2 supply component 10 and the crude oil supply component 20 can be connected to the reaction chamber 31 at the same time through the multi-way valve 50, wherein the multi-way valve 50 can be a three-way valve for connecting the above three, or it can be a four-way valve, a five-way valve or a six-way valve for connecting the remaining components to the reaction chamber 31. This embodiment does not limit the specific structure of the multi-way valve 50.

[0095] Furthermore, the diffusion reaction assembly 30 further includes a light-transmissive shell 34 , and the reaction chamber 31 is disposed in the shell 34 to form an annular cavity between the inner wall of the shell 34 and the outer wall of the reaction chamber 31 .

[0096] The CO 2 supply assembly 10 and the crude oil supply assembly 20 are connected to the feed port of the reaction chamber 311 through a multi-way valve 50 .

[0097] It should be noted that the shell 34 can be made of translucent resin, glass or other materials. The shell 34 is arranged outside the reaction chamber 31 to form an annular cavity between the two. The annular cavity can be connected to the pressure adjustment control 33 and the temperature adjustment control 32 to adjust the pressure and temperature in the reaction chamber 31. Compared with directly connecting the pressure adjustment control 33 and the temperature adjustment control 32 to the reaction chamber 31, the connection method of this embodiment is slower in the process of adjusting the temperature and pressure. The temperature and pressure of the reaction chamber 31 are affected by the pressure and temperature of the annular cavity to avoid sudden or frequent changes in the temperature and pressure of the reaction chamber 31, which affects the diffusion reaction of CO2 in crude oil.

[0098] The processing device may be a computer. After acquiring the above-mentioned measurement data, the computer determines the final diffusion coefficient through a preset calculation program, thereby improving the measurement efficiency of the diffusion coefficient.

[0099] Specifically, the diffusion reaction component 30 further includes a temperature adjustment component 32 .

[0100] The temperature adjustment unit 32 includes a heating cover 321 and a temperature control device 322 for controlling the heating temperature of the heating cover 321 . The heating cover 321 is surrounded by the outer periphery of the shell 34 , and the heating cover 321 is electrically connected to the temperature control device 322 .

[0101] It should be noted that the heating cover 321 can be wrapped outside the shell 34 and expose a light-transmissive portion for the reaction recording component 42 to observe the action. The heat of the heating cover 321 can act on the reaction chamber 31 through the annular cavity.

[0102] Specifically, the diffusion reaction component 30 further includes a pressure regulator 33 .

[0103] The annular cavity includes a first annular cavity 341 located above the reaction chamber 31 and a second annular cavity 342 located below the reaction chamber 31 , and the first annular cavity 341 and the second annular cavity 342 are not connected to each other.

[0104] The pressure regulating unit 33 includes a first pressure pump 331 and a second pressure pump 332 . The output end of the first pressure pump 331 is connected to the first annular cavity 341 for regulating the flow of liquid entering the first annular cavity 341 , thereby regulating the pressure value above the reaction chamber 31 .

[0105] The output end of the second pressure pump 332 is in communication with the second annular cavity 342 , and is used to adjust the flow rate of the liquid entering the second annular cavity 342 , thereby regulating the pressure value below the reaction chamber 31 .

[0106] It should be noted that, refer to the attached Figure 5 and attached Figure 6As shown, the first pressure pump 331 and the second pressure pump 332 can pump liquid into the first annular cavity 341 and the second annular cavity 342 to adjust the pressure values ​​on the upper and lower sides of the reaction chamber 31. The liquid can be water, oil or other liquids that can transmit pressure. In this embodiment, the first pressure pump 331 and the second pressure pump 332 are used to adjust the pressure values ​​on the upper and lower sides of the reaction chamber 31 respectively. The pressure values ​​at the two places can be the same or different. Such a setting can study the influence of the pressure on the upper and lower sides on the diffusion process of CO2 in crude oil, fully simulate the real environment of the oil and gas reservoir, and improve the authenticity and accuracy of the measurement of the diffusion coefficient of CO2 in crude oil.

[0107] For details, please refer to the attached Figure 2 As shown, the CO2 supply assembly 10 includes a CO2 gas cylinder 11 connected in sequence, a booster pump 12 for increasing the CO2 circulation pressure, a drying tube 13 for reducing the water content of the CO2 gas, a gas flow meter 14 for detecting the CO2 gas circulation rate, and a one-way valve 15.

[0108] The flow direction of the one-way valve 15 is toward the diffusion reaction assembly 30 , and the output end of the one-way valve 15 is communicated with one of the input ends of the multi-way valve 50 .

[0109] For details, please refer to the attached Figure 3 As shown, the crude oil supply assembly 20 includes a horizontal flow pump 21 and an intermediate container 22 .

[0110] The intermediate container 22 includes a liquid inlet and a liquid outlet respectively arranged at both ends of the intermediate container 22, and a piston 221 located inside the intermediate container 22. The piston 221 divides the inner cavity of the intermediate container 22 into a first chamber 222 and a second chamber 223 which are not connected to each other.

[0111] The first chamber 222 is communicated with the liquid inlet, and the second chamber 223 is communicated with the liquid outlet.

[0112] The liquid outlet of the horizontal flow pump 21 is communicated with the first chamber 222 through the liquid inlet, and the second chamber 223 is communicated with another input end of the multi-way valve 50 through the liquid outlet.

[0113] The second chamber 223 is used to contain crude oil. The horizontal flow pump 21 is used to pump liquid into the first chamber 222 to push the piston 221 to move toward the second chamber 223 so that the crude oil in the second chamber 223 enters the reaction chamber 311 through the liquid outlet and the multi-way valve 50 .

[0114] Furthermore, the device 100 for measuring the diffusion coefficient of CO2 in crude oil also includes a waste liquid recovery device 60 for recovering crude oil. The waste liquid recovery device 60 is connected to the discharge port of the reaction chamber 311. The remaining crude oil after the diffusion reaction can enter the waste liquid recovery device 60 through the discharge port.

[0115] Furthermore, a pressure regulating valve 70 is connected between the waste liquid recovery device 60 and the discharge port of the reaction chamber 311. The pressure regulating valve 70 is used to adjust the flow pressure of the discharge port of the reaction chamber 311, so as to facilitate the regulation of the reaction pressure value in the reaction chamber 311. Only when the pressure value in the reaction chamber 311 is higher than the pressure of the pressure regulating valve 70, the crude oil can enter the waste liquid recovery device 60 through the pressure regulating valve 70.

[0116] Furthermore, the device 100 for measuring the diffusion coefficient of CO2 in crude oil also includes a light source component 80, which is arranged outside the shell 34, and the light emitting direction of the light source component 80 is toward the reaction cavity 311 of the reaction chamber 31, so as to ensure that the reaction recording component 42 can clearly record the reaction process in the reaction chamber 31.

[0117] Furthermore, a sapphire glass sheet 90 is provided between the shell 34 and the reaction chamber 31. The sapphire glass sheet 90 has high hardness and high wear resistance, and can effectively prevent the outer wall surface of the reaction chamber 31 from being scratched or damaged during use.

[0118] The device for determining the diffusion coefficient of CO2 in crude oil provided in the first embodiment of the present invention is provided with a diffusion reaction component for CO2 to undergo a diffusion reaction in crude oil, wherein at least one blind hole is provided in the reaction chamber of the diffusion reaction component for analyzing the influence of microscopic pore throat conditions on the diffusion of CO2 in crude oil, so as to simulate the diffusion process of CO2 in the actual oil and gas reservoir. By providing a temperature adjustment control and a pressure adjustment control in the diffusion reaction component, the reaction pressure and reaction temperature in the reaction chamber can be effectively and accurately regulated, and the influence of the reaction pressure and reaction temperature on the CO2 diffusion process can be analyzed. By providing a pressure detection component and a reaction recording component in the measurement component, the reaction pressure, the volume of CO2 and the volume of crude oil in the diffusion reaction process are obtained in real time to finally determine the diffusion coefficient of CO2 in crude oil. Therefore, the first embodiment of the present invention can analyze the diffusion process of CO2 with crude oil under microscopic pore throat conditions and determine the diffusion coefficient of CO2 in crude oil, thereby improving the accuracy of the measurement of the diffusion coefficient of CO2 in crude oil.

[0119] Embodiment 2

[0120] Figure 7 A schematic flow chart of a method for determining the diffusion coefficient of CO2 in crude oil provided in Example 2 of the present invention.

[0121] See attached Figure 7 As shown, based on the above-mentioned embodiment 1, embodiment 2 of the present invention provides a method for measuring the diffusion coefficient of CO2 in crude oil. The method adopts the above-mentioned device 100 for measuring the diffusion coefficient of CO2 in crude oil. The method for measuring the diffusion coefficient of CO2 in crude oil includes the following steps:

[0122] S1: CO2 and crude oil are pumped into the reaction chamber 311 of the diffusion reaction assembly 30 to allow CO2 to diffuse in the crude oil.

[0123] S2: Detect the reaction temperature in the reaction chamber 311, the volume of CO2 and the volume of crude oil in the reaction chamber 311, the flow pressure at the multi-way valve 50, the reaction time of the diffusion reaction, the flow rate of CO2 and the cross-sectional area of ​​the blind hole 312 in the reaction chamber 311.

[0124] S3: Determine the diffusion coefficient of CO2 in crude oil according to the reaction temperature, reaction pressure, volume of CO2, volume of crude oil, flow pressure, reaction time, flow rate of CO2, and cross-sectional area of ​​the blind hole 312.

[0125] Further, the diffusion coefficient of CO2 in crude oil is determined according to the reaction temperature, reaction pressure, volume of CO2, volume of crude oil, circulation pressure, reaction time, flow rate of CO2, and cross-sectional area of ​​blind hole 312, specifically including:

[0126] According to the formula

[0127]

[0128] Determine the diffusion coefficient of CO2 in crude oil;

[0129] Where J represents the diffusion flux of CO2 in crude oil, and its unit is kg / (m 2 ·s); D represents the diffusion coefficient of CO2 in crude oil, in m 2 / s; A represents the cross-sectional area of ​​the blind hole 312; dt represents the reaction time; dm represents the flow rate of CO2 during the reaction time; is the concentration gradient of CO2 in crude oil.

[0130] It should be noted that in the above calculation process, the CO2 flow rate, reaction time and cross-sectional area of ​​the blind hole 312 can be used to determine The volume of CO2, the volume of crude oil and the specific location information of the reaction chamber 31 are used to determine Finally, the diffusion coefficient D can be calculated by the above formula, where the negative sign indicates that the diffusion direction of CO2 is opposite to the CO2 concentration gradient.

[0131] Other technical features are the same as those in Example 1 and can achieve the same technical effects, which will not be described in detail here.

[0132] The method for determining the diffusion coefficient of CO2 in crude oil provided in the second embodiment of the present invention is applied to the device for determining the diffusion coefficient of CO2 in crude oil in the first embodiment, and the device is provided with a diffusion reaction component for CO2 to undergo a diffusion reaction in crude oil, wherein at least one blind hole is provided in the reaction chamber in the diffusion reaction component, which is used to analyze the influence of microscopic pore throat conditions on the diffusion of CO2 in crude oil, so as to simulate the diffusion process of CO2 in the actual oil and gas reservoir. By providing a temperature adjustment control and a pressure adjustment control in the diffusion reaction component, the reaction pressure and reaction temperature in the reaction chamber can be effectively and accurately regulated, and the influence of the reaction pressure and reaction temperature on the CO2 diffusion process can be analyzed. By providing a pressure detection component and a reaction recording component in the measurement component, the reaction pressure, the volume of CO2 and the volume of crude oil in the diffusion reaction process are obtained in real time to finally determine the diffusion coefficient of CO2 in crude oil. Therefore, the second embodiment of the present invention can analyze the diffusion process of CO2 and crude oil under microscopic pore throat conditions and determine the diffusion coefficient of CO2 in crude oil, thereby improving the accuracy of the measurement of the diffusion coefficient of CO2 in crude oil.

[0133] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In the description of the present invention, "plurality" means two or more, unless otherwise precisely and specifically specified.

[0134] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0135] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for measuring the diffusion coefficient of CO2 in crude oil, characterized in that: include: CO2 supply components, crude oil supply components, diffusion reaction components and measurement components; The diffusion reaction assembly has a reaction chamber for diffusion reaction of CO2 and crude oil, the CO2 supply assembly and the crude oil supply assembly are connected to the reaction chamber of the reaction chamber through a multi-way valve, at least one blind hole communicating with the reaction chamber is provided in the reaction chamber, and the reaction chamber has a partially light-transmissive side wall; The measuring assembly includes a pressure detecting member arranged on the pipeline of the multi-way valve, a reaction recording assembly located outside the light-transmitting side wall of the reaction chamber, and a processing device electrically connected to the pressure detecting member and the reaction recording assembly, wherein the pressure detecting member is used to measure the reaction pressure in the reaction chamber, the reaction recording assembly is used to record the volume change of CO2 and the volume change of crude oil in the reaction chamber, and the processing device is used to determine the diffusion coefficient of CO2 in crude oil according to the reaction pressure, the volume of CO2 and the volume of crude oil; the reaction recording assembly includes at least a microscopic camera and a display electrically connected to the microscopic camera, wherein the microscopic camera records the reaction process in the reaction chamber and displays the reaction process through the display; The diffusion reaction assembly further comprises a light-transmitting shell, wherein the reaction chamber is disposed in the shell to form an annular cavity between the inner wall of the shell and the outer wall of the reaction chamber; The CO2 supply component and the crude oil supply component are connected to the feed port of the reaction chamber through a multi-way valve; the diffusion reaction component also includes a pressure regulator; The annular chamber comprises a first annular chamber located above the reaction chamber and a second annular chamber located below the reaction chamber, and the first annular chamber and the second annular chamber are not connected to each other; The pressure regulating component includes a first pressure pump and a second pressure pump, wherein the output end of the first pressure pump is connected to the first annular cavity, and is used to regulate the flow rate of the liquid entering the first annular cavity, thereby regulating the pressure value above the reaction chamber; The output end of the second pressure pump is communicated with the second annular cavity, and is used to adjust the flow rate of the liquid entering the second annular cavity, thereby regulating the pressure value below the reaction chamber.

2. The device for measuring the diffusion coefficient of CO2 in crude oil according to claim 1, characterized in that: The diffusion reaction component also includes a temperature control component; The temperature adjustment unit comprises a heating cover and a temperature control device for controlling the heating temperature of the heating cover. The heating cover is surrounded by the outer periphery of the shell, and the heating cover is electrically connected to the temperature control device.

3. The device for measuring the diffusion coefficient of CO2 in crude oil according to claim 1 or 2, characterized in that: The CO2 supply assembly includes a CO2 gas cylinder, a booster pump for increasing the CO2 circulation pressure, a drying tube for reducing the water content of the CO2 gas, a gas flow meter for detecting the CO2 gas circulation rate, and a one-way valve connected in sequence; The flow direction of the one-way valve is toward the diffusion reaction component, and the output end of the one-way valve is communicated with one of the input ends of the multi-way valve.

4. The device for measuring the diffusion coefficient of CO2 in crude oil according to claim 1 or 2, characterized in that: The crude oil supply assembly includes a horizontal flow pump and an intermediate container; The intermediate container comprises a liquid inlet and a liquid outlet respectively arranged at two ends of the intermediate container, and a piston located inside the intermediate container, wherein the piston separates the inner cavity of the intermediate container into a first chamber and a second chamber which are not connected to each other; The first chamber is in communication with the liquid inlet, and the second chamber is in communication with the liquid outlet; The liquid outlet of the horizontal flow pump is connected to the first chamber through the liquid inlet, and the second chamber is connected to another input end of the multi-way valve through the liquid outlet; The second chamber is used to contain crude oil, and the horizontal flow pump is used to pump liquid into the first chamber to push the piston to move toward the second chamber, so that the crude oil in the second chamber enters the reaction chamber through the liquid outlet and the multi-way valve.

5. The device for measuring the diffusion coefficient of CO2 in crude oil according to claim 1 or 2, characterized in that: It also includes a waste liquid recovery device for recovering crude oil, and the waste liquid recovery device is connected to the discharge port of the reaction chamber.

6. The device for measuring the diffusion coefficient of CO2 in crude oil according to claim 5, characterized in that: A pressure regulating valve is also connected between the waste liquid recovery device and the discharge port of the reaction chamber, and the pressure regulating valve is used to adjust the flow pressure of the discharge port of the reaction chamber.

7. The device for measuring the diffusion coefficient of CO2 in crude oil according to claim 1, characterized in that: It also includes a light source component, which is arranged outside the shell, and the light emitting direction of the light source component is toward the reaction cavity of the reaction chamber.

8. The device for measuring the diffusion coefficient of CO2 in crude oil according to claim 1, characterized in that: A sapphire glass sheet is arranged between the shell and the reaction chamber.

9. A method for determining the diffusion coefficient of CO2 in crude oil, characterized in that: The method for measuring the diffusion coefficient of CO2 in crude oil adopts the device for measuring the diffusion coefficient of CO2 in crude oil according to any one of claims 1 to 8, and the method for measuring the diffusion coefficient of CO2 in crude oil comprises the following steps: Pumping CO2 and crude oil into the reaction chamber of the diffusion reaction component to allow CO2 to diffuse in the crude oil; Detecting the reaction temperature in the reaction chamber, the volume of CO2 and the volume of crude oil in the reaction chamber, the flow pressure at the multi-way valve, the reaction time of the diffusion reaction, the flow rate of CO2 and the cross-sectional area of ​​the blind hole in the reaction chamber; The diffusion coefficient of the CO2 in the crude oil is determined according to the reaction temperature, the reaction pressure, the volume of the CO2, the volume of the crude oil, the circulation pressure, the reaction time, the flow rate of the CO2, and the cross-sectional area of ​​the blind hole.

10. The method for determining the diffusion coefficient of CO2 in crude oil according to claim 9, characterized in that: The step of determining the diffusion coefficient of CO2 in crude oil according to the reaction temperature, the reaction pressure, the volume of CO2, the volume of crude oil, the circulation pressure, the reaction time, the flow rate of CO2, and the cross-sectional area of ​​the blind hole specifically includes: According to the formula Determine the Diffusion coefficient in crude oil; Wherein, the J represents The diffusion flux in crude oil is expressed in ; The D represents Diffusion coefficient in crude oil, in units of ; A represents the cross-sectional area of ​​the blind hole; dt represents the reaction time; dm represents the flow rate of CO2 during the reaction time; is the concentration gradient of CO2 in crude oil.

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