Thickened oil emulsion ternary phase diagram drawing method

Abstract

The invention relates to a method for drawing a ternary phase diagram of a thick oil emulsion, which belongs to the technical field of oil-gas field development and comprises the following steps: preparing a viscosity reducer and a mineralized aqueous solution; taking points to calculate the relative volume of each component of the thick oil emulsion and the mass concentration of the viscosity reducer; carrying out an emulsification experiment according to the relative volume; determining the phase equilibrium state of the emulsion; calculating the concentration of an oil-water dispersion phase; determining a phase state partition boundary; drawing a ternary phase diagram of the thick oil emulsion; given conditions are used for determining the phase state and the dispersion phase concentration. According to the method, the influence of the mass concentration, the water-oil ratio and the mineralization degree of the viscosity reducer on the phase state of the emulsion system is obtained by carrying out experiments, so that the phase state change of the emulsion is qualitatively and quantitatively represented. By revealing the influence mechanism of the mass concentration of the viscosity reducer, the mineralized water and the thickened oil on the phase equilibrium state of the emulsion, the ternary phase diagram of the thickened oil emulsion system is constructed, and the phase state of the emulsion under the relative volumes of different chemical agents can be conveniently judged.

Description

Technical Field

[0001] The invention relates to a method for drawing a ternary phase diagram of a thick oil emulsion, and belongs to the technical field of oil and gas field development. Background Art

[0002] The key to heavy oil reservoir development is to reduce crude oil viscosity. Cold production through chemical emulsification to reduce viscosity is an important research direction for efficient heavy oil development. In heavy oil chemical composite cold production, different phases such as water, oil, water-in-oil emulsion and oil-in-water emulsion will appear under the influence of reservoir conditions and fluid conditions. The phase equilibrium characteristics are relatively complex, which has an important impact on the development effect.

[0003] At present, the research on emulsion phase is mainly carried out on microemulsion system with nanometer particle size, while the particle size of emulsion system is micrometer level, which is a thermodynamically unstable system and its phase change is extremely complex. Therefore, conducting experimental research on heavy oil emulsion phase equilibrium and drawing ternary phase diagram of heavy oil emulsion have become the key to guiding the optimization of mine development.

[0004] At present, there are methods for drawing pseudo-ternary phase diagrams of microemulsions, which can determine the range of different emulsion types based on the phase diagram, intuitively reflect the influence of each phase concentration on the phase state at phase equilibrium, and determine the composition of single-phase emulsions. However, the existing drawing methods lack the emulsion state equation when judging the emulsion phase state, and cannot accurately predict the emulsion type; and due to the instability of emulsions, there are few methods for studying emulsion phase equilibrium models. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a method for drawing a ternary phase diagram of a heavy oil emulsion.

[0006] The present invention conducts phase equilibrium characteristic experiments on the heavy oil / viscosity reducer / water emulsion system, and studies the microscopic characteristics of the emulsion system through a microfluidic test system, a laser particle size analyzer observation experiment, and a conductivity meter. The invention reveals the influence mechanism of viscosity reducer, mineralized water, and heavy oil mass concentration on the emulsion phase equilibrium, constructs a ternary phase diagram of the heavy oil emulsion system, and proposes a method for drawing a ternary phase diagram of the heavy oil emulsion. The invention overcomes the disadvantages of the traditional means of difficult measurement and drawing.

[0007] The technical solution of the present invention is as follows: A method for drawing a ternary phase diagram of a heavy oil emulsion, comprising: Prepare viscosity reducer and mineralized aqueous solution; Take points to calculate the relative volume of each component of the heavy oil emulsion and the mass concentration of the viscosity reducer; Carry out emulsification experiments based on relative volumes; Determine the phase equilibrium state of the emulsion; Calculate the concentration of oil-water dispersed phase; Determine the phase separation boundary; Draw the ternary phase diagram of heavy oil emulsion; Determine the phase state and dispersed phase concentration under given conditions.

[0008] Preferably, according to the present invention, the viscosity reducing agent and the mineralized aqueous solution are prepared; comprising: The viscosity reducer and distilled water are mixed in a ratio of 100:1 to 1000:1, and stirred thoroughly with a stirrer to prepare a viscosity reducer solution with a mass concentration of 0.01wt% to 1.0wt% and placed in a measuring cylinder A; Take a volume of distilled water and a mass of sodium chloride to make a mineralization degree of ω Place the mineralized water in the measuring cylinder B; place the heavy oil with a volume of a / 2 in the measuring cylinder C, where a is in the range of 20-100 mL, x is in the range of 0.1-2.0 g, ω The value range is 1000~100000 mg / L.

[0009] According to the preferred embodiment of the present invention, the relative volumes of the components of the heavy oil emulsion and the mass concentration of the viscosity reducer are calculated by taking points; including: Draw a triangle with heavy oil, mineral water and viscosity reducer as vertices, add a scale line from 0 to 1 between every two vertices, and evenly select points in the triangle. The relative volumes of heavy oil and mineral water and the mass concentration of viscosity reducer are calculated based on the positions of the points.

[0010] Preferably, according to the present invention, the relative volume of each component of the heavy oil emulsion and the mass concentration of the viscosity reducer are calculated as follows: a straight line parallel to the base of the triangle is drawn through the selected point, and the value corresponding to the intersection with the left side is the relative volume of water, and the value corresponding to the intersection with the right side is the relative volume of the heavy oil, and the sum of the two is 1; at the same time, an extension line is drawn through the triangle vertex and the selected point, and the value corresponding to the intersection with the base of the triangle is multiplied by 1.0% to obtain the mass concentration of the viscosity reducer.

[0011] Preferably according to the present invention, the number of taking points is not less than 50.

[0012] Preferably, according to the present invention, an emulsification experiment is carried out according to relative volume; comprising: Select a point in the triangle diagram, take a' volume of heavy oil, b' volume of viscosity reducer and mineralized aqueous solution from measuring cylinders A and B respectively, mix them in measuring cylinder C, and obtain a volume of oil-water mixture c'. Calculate the sampling volume of each liquid according to the relative volume of heavy oil and aqueous solution; among which, the sampling volume of heavy oil is: c×e; the relative volume of aqueous solution is: c×(1-e), e refers to the relative volume of heavy oil, the value range of a' is 10~50mL; the value range of b' is 10~150mL, and the value range of c' is 20~200mL; Use an emulsifier to emulsify the water mixture at a constant speed to eventually obtain a uniform emulsion system. Seal the measuring cylinder C and let it stand for 7 to 21 days. The emulsion system in the measuring cylinder will show a stratified state. Change the point location and repeat the emulsification experiment.

[0013] Preferably, according to the present invention, determining the emulsion phase equilibrium state comprises: Each equilibrium phase of the emulsion is sampled, and the conductivity of the emulsion at phase equilibrium is tested using a conductivity meter to distinguish between water-in-oil emulsions and oil-in-water emulsions. The emulsion samples are microscopically observed using an electron microscope to further distinguish the phase equilibrium state of the emulsion.

[0014] Preferably, according to the present invention, the concentration of the oil-water dispersed phase is calculated; comprising: Calculate the volume difference of the oil-water phase before and after emulsification of heavy oil, viscosity reducer and mineralized water respectively, calculate the volume concentration of the dispersed phase in the emulsion, and mark them in the triangle diagram respectively to obtain the oil-water dispersed phase concentration; f=g / h×100%; where f refers to the concentration of the oil dispersed phase, g refers to the volume of the oil phase of the water-in-oil emulsion, and h refers to the total volume of the emulsion; i=j / h×100%; where i refers to the concentration of the water dispersed phase and j refers to the volume of the water phase of the oil-in-water emulsion.

[0015] Preferably, according to the present invention, determining the phase division boundary line comprises: According to the experimental results, different symbols are used to represent different emulsion types, and their positions are marked in the triangle diagram. Points at the boundaries of different symbol aggregation areas are taken to draw phase partition boundaries.

[0016] Preferably, according to the present invention, determining the phase division boundary line comprises: In the triangle diagram, if the upper part is the oil phase and the lower part is the water-in-oil emulsion, it is a water-in-water emulsion-oil phase equilibrium state, which is recorded as a zone, and the points in it are marked with circular symbols in the triangle diagram; If the upper part is a water-in-oil emulsion and the lower part is an oil-in-water emulsion, it is an oil-in-water-in-oil emulsion phase equilibrium state, recorded as two zones, and the points in it are marked with triangle signs in the triangle diagram; If the upper part is a water-in-oil emulsion and the lower part is an aqueous phase, it is a water-in-oil emulsion-aqueous phase equilibrium state, which is recorded as three regions, and the points in them are marked with square symbols in the triangular diagram; If the upper part is the oil phase and the lower part is the water phase, it is a water-oil phase equilibrium state, which is recorded as four zones, and the points in the zones are marked with diamond marks in the triangular diagram.

[0017] Preferably, according to the present invention, drawing a ternary phase diagram of a heavy oil emulsion comprises: For a certain phase emulsion dispersed phase concentration, the corresponding contour map is drawn inside the triangle. The established phase partition and dispersed phase concentration contour map is the ternary phase diagram of the heavy oil emulsion.

[0018] Preferably, according to the present invention, the steps for drawing the ternary phase diagram of the heavy oil emulsion are as follows: (1) Take the vertex of the viscosity reducer in the triangle diagram as the origin, extend the triangle base to the right as the X-axis to establish a rectangular coordinate system, so that the ternary phase diagram is located in the first quadrant of the coordinate system, place the phase boundary line in the ternary phase diagram in the rectangular coordinate system, determine the (x, y) rectangular coordinates of each point on the phase boundary line and perform regression fitting; the (x, y) rectangular coordinates are converted into the corresponding proportions of each component on the ternary phase diagram, as follows: ; ; ; Wherein, o represents the oil component, v represents the viscosity reducer component, w represents the water component, and x and y represent the horizontal and vertical coordinates of the established rectangular coordinate system, respectively; (2) Establish the function of the phase partition boundary of the ternary phase diagram of the heavy oil emulsion system, perform fitting calculations on the different phase boundary lines drawn in the ternary phase diagram, and establish a mathematical model for the phase partition characterization of the ternary phase diagram of the heavy oil emulsion system, that is, the boundary line mathematical model, as shown below: ; in, y 1 represents the boundary function between the first and second zones on the ternary phase diagram of the heavy oil emulsion system, which is represented by a solid line in the ternary phase diagram; y 2 represents the boundary function between the second and third zones of the heavy oil emulsion system, which is represented by a dotted line in the ternary phase diagram; y 3 represents the boundary function of the third and fourth zones of the heavy oil emulsion system, which is represented by a dotted line combined with dots in the ternary phase diagram.

[0019] Preferably according to the present invention, the data processing software includes Excel and Origin.

[0020] Preferably, according to the present invention, the phase state and the dispersed phase concentration are determined under given conditions; including: Given the ratio of heavy oil to mineralized water and the mass concentration of the viscosity reducer, the point corresponding to this condition in the plane coordinate system is added to the ternary phase diagram of the heavy oil emulsion. The corresponding phase state is determined according to the area where the point is located, and the emulsion concentration value is obtained by interpolation based on the dispersed phase concentration contour line.

[0021] The beneficial effects of the present invention are: 1. The present invention obtains the influence of viscosity reducer mass concentration, water-oil ratio and salinity on the phase state of emulsion system by conducting experiments, so that the phase state change of emulsion can be qualitatively and quantitatively characterized.

[0022] 2. The present invention reveals the influence mechanism of viscosity reducer, mineralized water and heavy oil mass concentration on the emulsion phase equilibrium state, constructs a ternary phase diagram of heavy oil emulsion system, and realizes convenient judgment of the emulsion phase state under different relative volumes of chemical agents. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic flow diagram of a method for drawing a ternary phase diagram of a heavy oil emulsion according to the present invention; Figure 2 is the relationship between different viscosity reducer mass concentrations and the volume fraction of the equilibrium phase of heavy oil emulsion; Figure 3 It is the ternary phase diagram of heavy oil emulsion system; Figure 4 is the oil-water dispersed phase concentration contour map; Figure 5 It is the calculation chart of the boundary line of the phase partition of heavy oil emulsion. DETAILED DESCRIPTION

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments, but is not limited thereto.

[0025] Example 1 A method for drawing a ternary phase diagram of a heavy oil emulsion, such as Figure 1 As shown, including: Prepare viscosity reducer and mineralized aqueous solution; Take points to calculate the relative volume of each component of the heavy oil emulsion and the mass concentration of the viscosity reducer; Carry out emulsification experiments based on relative volumes; Determine the phase equilibrium state of the emulsion; phase equilibrium refers to the limit state reached by the changes of each phase in a multiphase system. At this time, there is no substance transferring between phases on a macroscopic level, but there are still substances transferring between phases in opposite directions on a microscopic level, and the speed is equal.

[0026] Calculate the oil-water dispersed phase concentration; dispersed phase concentration: refers to the volume fraction of the oil phase in the water-in-oil emulsion or the volume fraction of the water phase in the oil-in-water emulsion.

[0027] Determine the phase separation boundary; Draw the ternary phase diagram of heavy oil emulsion; Determine the phase state and dispersed phase concentration under given conditions.

[0028] Example 2 The method for drawing a ternary phase diagram of a heavy oil emulsion according to Example 1 is different in that: Preparation of viscosity reducing agent and mineralizing aqueous solution; including: The viscosity reducer and distilled water are mixed in a ratio of 100:1 to 1000:1, and stirred thoroughly with a stirrer to prepare a viscosity reducer solution with a mass concentration of 0.01wt% to 1.0wt% and placed in a measuring cylinder A; Take a volume of distilled water and a mass of sodium chloride to make a mineralization degree of ω Place the mineralized water in the measuring cylinder B; place the heavy oil with a volume of a / 2 in the measuring cylinder C, where a is in the range of 20-100 mL, x is in the range of 0.1-2.0 g, ω The value range is 1000~100000 mg / L.

[0029] The viscosity reducer used is a water-soluble viscosity reducer.

[0030] Calculate the relative volume of each component of the heavy oil emulsion and the mass concentration of the viscosity reducer; including: Draw a triangle with heavy oil, mineral water and viscosity reducer as vertices, add a scale line from 0 to 1 (in order to determine the composition ratio of each component) between every two vertices, and evenly select points in the triangle. The relative volumes of heavy oil and mineral water and the mass concentration of viscosity reducer are calculated based on the positions of the points.

[0031] The relative volume of each component of the heavy oil emulsion and the mass concentration of the viscosity reducer are calculated as follows: draw a straight line through the selected point parallel to the base of the triangle, the value corresponding to the intersection with the left side is the relative volume of water, and the value corresponding to the intersection with the right side is the relative volume of the heavy oil, and the sum of the two is 1; at the same time, draw an extension line through the triangle vertex and the selected point, and the value corresponding to the intersection with the base of the triangle multiplied by 1.0% is the mass concentration of the viscosity reducer.

[0032] The number of points to be taken shall not be less than 50.

[0033] Conduct emulsification experiments based on relative volumes; including: Select a point in the triangle diagram, take a' volume of heavy oil, b' volume of viscosity reducer and mineralized aqueous solution from measuring cylinders A and B respectively, mix them in measuring cylinder C, and obtain a volume of oil-water mixture c'. Calculate the sampling volume of each liquid according to the relative volume of heavy oil and aqueous solution; among which, the sampling volume of heavy oil is: c×e; the relative volume of aqueous solution is: c×(1-e), e refers to the relative volume of heavy oil, the value range of a' is 10~50mL; the value range of b' is 10~150mL, and the value range of c' is 20~200mL; Use an emulsifier to emulsify the water mixture at a constant speed under a certain shear rate to eventually obtain a uniform emulsion system. Seal the measuring cylinder C and let it stand for 7 to 21 days. The emulsion system in the measuring cylinder will show a stratified state. Change the point location and repeat the emulsification experiment.

[0034] Determine the phase equilibrium state of an emulsion; including: Each equilibrium phase of the emulsion is sampled, and the conductivity of the emulsion at phase equilibrium is tested using a conductivity meter to distinguish between water-in-oil emulsions and oil-in-water emulsions. The conductivity of water-in-oil emulsions is much greater than that of oil-in-water emulsions. An electron microscope is used to observe the emulsion samples microscopically to further distinguish the phase equilibrium state of the emulsion. Water-in-oil emulsions are oil droplets dispersed in a bright aqueous solution, while water-in-oil emulsions are bright water droplets dispersed in a continuous oil phase.

[0035] Calculates the concentration of oil-water dispersed phase; includes: Calculate the volume difference of the oil-water phase before and after emulsification of heavy oil, viscosity reducer and mineralized water respectively, calculate the volume concentration of the dispersed phase in the emulsion, and mark them in the triangle diagram respectively to obtain the oil-water dispersed phase concentration; f=g / h×100%; where f refers to the concentration of the oil dispersed phase, g refers to the volume of the oil phase of the water-in-oil emulsion, and h refers to the total volume of the emulsion; i=j / h×100%; where i refers to the concentration of the water dispersed phase and j refers to the volume of the water phase of the oil-in-water emulsion.

[0036] Determine the phase separation boundary; including: According to the experimental results, different symbols are used to represent different emulsion types, and their positions are marked in the triangle diagram. Points at the boundaries of different symbol aggregation areas are taken to draw phase partition boundaries.

[0037] Determine the phase separation boundary; including: In the triangle diagram, if the upper part is the oil phase and the lower part is the water-in-oil emulsion, it is a water-in-water emulsion-oil phase equilibrium state, which is recorded as a zone, and the points in it are marked with circular symbols in the triangle diagram; If the upper part is a water-in-oil emulsion and the lower part is an oil-in-water emulsion, it is an oil-in-water-in-oil emulsion phase equilibrium state, recorded as two zones, and the points in it are marked with triangle signs in the triangle diagram; If the upper part is a water-in-oil emulsion and the lower part is an aqueous phase, it is a water-in-oil emulsion-aqueous phase equilibrium state, which is recorded as three regions, and the points in them are marked with square symbols in the triangular diagram; If the upper part is the oil phase and the lower part is the water phase, it is a water-oil phase equilibrium state, which is recorded as four zones, and the points in the zones are marked with diamond marks in the triangular diagram.

[0038] Draw the ternary phase diagram of heavy oil emulsion; including: The corresponding contour map of the dispersed phase concentration of a certain phase emulsion is drawn inside the triangle using data processing software. The established phase partition and the contour map of the dispersed phase concentration are the ternary phase diagram of the heavy oil emulsion.

[0039] When drawing the dispersed phase concentration contour map, the oil dispersed phase concentration contour lines are represented by dots, and the water dispersed phase concentration is represented by thin solid lines.

[0040] The steps for drawing the ternary phase diagram of heavy oil emulsion are as follows: (1) Take the vertex of the viscosity reducer in the triangle diagram as the origin, extend the triangle base to the right as the X-axis to establish a rectangular coordinate system, so that the ternary phase diagram is located in the first quadrant of the coordinate system, place the phase boundary line in the ternary phase diagram in the rectangular coordinate system, determine the (x, y) rectangular coordinates of each point on the phase boundary line and perform regression fitting; the (x, y) rectangular coordinates are converted into the corresponding proportions of each component on the ternary phase diagram, as follows: ; ; ; Wherein, o represents the oil component, v represents the viscosity reducer component, w represents the water component, and x and y represent the horizontal and vertical coordinates of the established rectangular coordinate system, respectively; (2) Establish the function of the phase partition boundary of the ternary phase diagram of the heavy oil emulsion system, perform fitting calculations on the different phase boundary lines drawn in the ternary phase diagram, and establish a mathematical model for the phase partition characterization of the ternary phase diagram of the heavy oil emulsion system, that is, the boundary line mathematical model, as shown below: ; in, y 1 represents the boundary function between the first and second zones on the ternary phase diagram of the heavy oil emulsion system, which is represented by a solid line in the ternary phase diagram; y 2 represents the boundary function between the second and third zones of the heavy oil emulsion system, which is represented by a dotted line in the ternary phase diagram; y 3 represents the boundary function of the third and fourth zones of the heavy oil emulsion system, which is represented by a dotted line combined with dots in the ternary phase diagram.

[0041] Data processing software includes Excel and Origin.

[0042] Determine the phase state and dispersed phase concentration under given conditions; including: Given the ratio of heavy oil to mineralized water and the mass concentration of the viscosity reducer, the point corresponding to this condition in the plane coordinate system is added to the ternary phase diagram of the heavy oil emulsion. The corresponding phase state is determined according to the area where the point is located, and the emulsion concentration value is obtained by interpolation based on the dispersed phase concentration contour line.

[0043] Example 3 The method for drawing a ternary phase diagram of a heavy oil emulsion according to Example 2 is different in that: Mix the viscosity reducer and distilled water in a certain proportion, stir them thoroughly with a stirrer, and prepare a viscosity reducer solution with a mass concentration of 0.3wt% and place it in a measuring cylinder A; Take 100 mL of distilled water, take 1.0 g of sodium chloride, and prepare the mineralized water with a mineralization degree of 10000 mg / L into measuring cylinder B, and take a certain volume of heavy oil into measuring cylinder C; Pick points evenly in the triangle, according to the position of the points. Figure 2 As shown, the relative volumes of the three liquids and the mass concentration of the viscosity reducer are calculated.

[0044] Take 12.5 mL of heavy oil, 12.5 mL of viscosity reducer solution and 25 mL of mineral water in measuring cylinders A, B and C respectively, mix them in measuring cylinder D to obtain a total of 50 mL of oil-water mixture, and calculate the sampling volume of each liquid.

[0045] The measuring cylinder C was sealed and left to stand for 14 days.

[0046] Example 4 The method for drawing a ternary phase diagram of a heavy oil emulsion according to Example 2 is different in that: The viscosity reducer and distilled water are mixed in a certain proportion, and stirred fully with a stirrer to prepare a viscosity reducer solution with a certain mass concentration; Take a certain volume of distilled water and a certain mass of sodium chloride and prepare a mineralization degree of ω Place the mineralized water in the measuring cylinder B, and place a certain volume of heavy oil in the measuring cylinder C; Draw a triangle with heavy oil, viscosity reducer, and mineralized water as vertices, add a scale line from 0 to 1 between every two vertices, evenly select points in the triangle, and calculate the relative volumes of the three liquids based on the positions of the points; Take a volume of heavy oil, b volume of viscosity reducer solution and c volume of mineral water in measuring cylinders A, B and C respectively, mix them in measuring cylinder D to obtain a total of 50 mL of oil-water mixture, and calculate the sampling volume of each liquid.

[0047] Use an emulsifier to emulsify it at a constant speed at a certain shear rate, and finally obtain a uniform emulsion system. Seal the experimental measuring cylinder and let it stand for 14 days. The emulsion system in the measuring cylinder is in a stratified state. Change the point of collection and repeat this step; Sampling each equilibrium phase of the emulsion, using a conductivity meter to test the conductivity of the emulsion when it is in phase equilibrium, and using an electron microscope to observe the emulsion sample microscopically to determine the phase equilibrium state of the emulsion; Calculate the volume difference of the oil-water phase before and after the emulsification of heavy oil / viscosity reducer / water, calculate the volume concentration of the dispersed phase in the emulsion, and mark them in the triangle diagram to obtain the oil-water dispersed phase concentration; According to the experimental results, different symbols are used to represent different emulsion types, and their positions are marked in the triangle diagram. The points at the boundaries of the different symbol aggregation areas are taken to draw the phase division boundary lines; Use data processing software to draw the corresponding contour map of the dispersed phase concentration of a certain phase emulsion inside the triangle, such as Figure 4 As shown in the figure, the established phase partition and dispersed phase concentration contour diagram is the ternary phase diagram of heavy oil emulsion; The function of the phase partition boundary of the ternary phase diagram of the heavy oil emulsion system is established, and the different phase boundary lines drawn in the ternary phase diagram are fitted and calculated. Figure 5 It is the calculation chart of the boundary line of the phase partition of the heavy oil emulsion, and the mathematical model of the phase partition characterization of the ternary phase diagram of the heavy oil emulsion system, that is, the mathematical model of the dividing line, is established as follows: ; Figure 3 is the ternary phase diagram of the heavy oil emulsion system, where y 1 represents the boundary function between area 1 and area 2 on the ternary phase diagram of the heavy oil emulsion system, which is represented by a solid line in the figure; y 2 represents the boundary function of the heavy oil emulsion system between regions 2 and 3. It is represented by a dotted line in the figure; y 3 represents the boundary function of the 3rd and 4th zones of the heavy oil emulsion system, which is represented by a dotted line combined with dots in the figure.

[0048] Given that the mass concentrations of heavy oil, viscosity reducer and mineralized water are 0.25, 0.3 and 0.45 respectively, this point is added to the ternary phase diagram of heavy oil emulsion. According to the area where the point is located, the corresponding phase state is determined to be the oil-in-water emulsion-water phase equilibrium state. According to the interpolation of the dispersed phase concentration contour lines, the oil dispersed phase concentration is 37 and the water dispersed phase concentration is 22.

[0049] The above embodiments are only used to illustrate the present invention, and any equivalent transformations and improvements based on the technical solution of the present invention should not be excluded from the protection scope of the present invention.

Claims

1. A method for drawing a ternary phase diagram of a heavy oil emulsion, characterized in that: include: Prepare viscosity reducer and mineralized aqueous solution; Take points to calculate the relative volume of each component of the heavy oil emulsion and the mass concentration of the viscosity reducer; Carry out emulsification experiments based on relative volumes; Determine the phase equilibrium state of the emulsion; Calculate the concentration of oil-water dispersed phase; Determine the phase separation boundary; Draw the ternary phase diagram of heavy oil emulsion; Determine the phase state and dispersed phase concentration under given conditions.

2. The method for drawing a ternary phase diagram of a heavy oil emulsion according to claim 1, characterized in that: Prepare viscosity reducer and mineralized aqueous solution; include: The viscosity reducer and distilled water are mixed in a ratio of 100:1 to 1000:1, and stirred thoroughly with a stirrer to prepare a viscosity reducer solution with a mass concentration of 0.01wt% to 1.0wt% and placed in a measuring cylinder A; Take a volume of distilled water and a mass of sodium chloride to make a mineralization degree of ω Place the mineralized water in the measuring cylinder B; place the heavy oil with a volume of a / 2 in the measuring cylinder C, where a is in the range of 20-100 mL, x is in the range of 0.1-2.0 g, ω The value range is 1000~100000 mg / L.

3. The method for drawing a ternary phase diagram of a heavy oil emulsion according to claim 1, characterized in that: Calculate the relative volume of each component of the heavy oil emulsion and the mass concentration of the viscosity reducer; including: Draw a triangle with heavy oil, mineral water and viscosity reducer as vertices, add a scale line from 0 to 1 between every two vertices, and evenly select points in the triangle. The relative volumes of heavy oil and mineral water and the mass concentration of viscosity reducer are calculated based on the positions of the points.

4. The method for drawing a ternary phase diagram of a heavy oil emulsion according to claim 3, characterized in that: The calculation method for the relative volume of each component of the heavy oil emulsion and the mass concentration of the viscosity reducer is as follows: draw a straight line through the selected point parallel to the base of the triangle, the value corresponding to the intersection with the left side is the relative volume of water, and the value corresponding to the intersection with the right side is the relative volume of the heavy oil, and the sum of the two is 1; at the same time, draw an extension line through the triangle vertex and the selected point, and the value corresponding to the intersection with the base of the triangle multiplied by 1.0% is the mass concentration of the viscosity reducer; the number of points taken is not less than 50.

5. The method for drawing a ternary phase diagram of a heavy oil emulsion according to claim 3, characterized in that: Emulsification experiments based on relative volumes; including: Select a point in the triangle diagram, take a' volume of heavy oil, b' volume of viscosity reducer and mineralized aqueous solution from measuring cylinders A and B respectively, mix them in measuring cylinder C, and obtain a volume of oil-water mixture c'. Calculate the sampling volume of each liquid according to the relative volume of heavy oil and aqueous solution; among which, the sampling volume of heavy oil is: c×e; the relative volume of aqueous solution is: c×(1-e), e refers to the relative volume of heavy oil, the value range of a' is 10~50mL; the value range of b' is 10~150mL, and the value range of c' is 20~200mL; Use an emulsifier to emulsify the water mixture at a constant speed to eventually obtain a uniform emulsion system. Seal the measuring cylinder C and let it stand for 7 to 21 days. The emulsion system in the measuring cylinder will show a stratified state. Change the point location and repeat the emulsification experiment.

6. The method for drawing a ternary phase diagram of a heavy oil emulsion according to claim 1, characterized in that: Determine the phase equilibrium state of an emulsion; including: Sampling each equilibrium phase of the emulsion, using a conductivity meter to test the conductivity of the emulsion at phase equilibrium, distinguishing between water-in-oil emulsions and oil-in-water emulsions, and using an electron microscope to observe the emulsion samples microscopically to further distinguish the phase equilibrium state of the emulsion; Calculates the concentration of oil-water dispersed phase; includes: Calculate the volume difference of the oil-water phase before and after emulsification of heavy oil, viscosity reducer and mineralized water respectively, calculate the volume concentration of the dispersed phase in the emulsion, and mark them in the triangle diagram respectively to obtain the oil-water dispersed phase concentration; f=g / h×100%; where f refers to the concentration of the oil dispersed phase, g refers to the volume of the oil phase of the water-in-oil emulsion, and h refers to the total volume of the emulsion; i=j / h×100%; where i refers to the concentration of the water dispersed phase and j refers to the volume of the water phase of the oil-in-water emulsion.

7. The method for drawing a ternary phase diagram of a heavy oil emulsion according to claim 3, characterized in that: Determine the phase separation boundary; including: In the triangle diagram, if the upper part is the oil phase and the lower part is the water-in-oil emulsion, it is a water-in-water emulsion-oil phase equilibrium state, which is recorded as a zone, and the points in it are marked with circular symbols in the triangle diagram; If the upper part is a water-in-oil emulsion and the lower part is an oil-in-water emulsion, it is an oil-in-water-in-oil emulsion phase equilibrium state, recorded as two zones, and the points in it are marked with triangle signs in the triangle diagram; If the upper part is a water-in-oil emulsion and the lower part is an aqueous phase, it is an oil-in-water emulsion-aqueous phase equilibrium state, which is recorded as three regions, and the points in them are marked with square symbols in the triangular diagram; If the upper part is the oil phase and the lower part is the water phase, it is a water-oil phase equilibrium state, which is recorded as four zones, and the points in the zones are marked with diamond marks in the triangular diagram.

8. The method for drawing a ternary phase diagram of a heavy oil emulsion according to claim 1, characterized in that: Draw the ternary phase diagram of heavy oil emulsion; including: For a certain phase emulsion dispersed phase concentration, the corresponding contour map is drawn inside the triangle. The established phase partition and dispersed phase concentration contour map is the ternary phase diagram of the heavy oil emulsion.

9. The method for drawing a ternary phase diagram of a heavy oil emulsion according to claim 1, characterized in that: The steps for drawing the ternary phase diagram of heavy oil emulsion are as follows: (1) Take the vertex of the viscosity reducer in the triangle diagram as the origin, extend the triangle base to the right as the X-axis to establish a rectangular coordinate system, so that the ternary phase diagram is located in the first quadrant of the coordinate system, place the phase boundary line in the ternary phase diagram in the rectangular coordinate system, determine the (x, y) rectangular coordinates of each point on the phase boundary line and perform regression fitting; the (x, y) rectangular coordinates are converted into the corresponding proportions of each component on the ternary phase diagram, as follows: ； ； ； Wherein, o represents the oil component, v represents the viscosity reducer component, w represents the water component, and x and y represent the horizontal and vertical coordinates of the established rectangular coordinate system, respectively; (2) Establish the function of the phase partition boundary of the ternary phase diagram of the heavy oil emulsion system, perform fitting calculations on the different phase boundary lines drawn in the ternary phase diagram, and establish a mathematical model for the phase partition characterization of the ternary phase diagram of the heavy oil emulsion system, that is, the boundary line mathematical model, as shown below: ； in, y 1 represents the boundary function between the first and second zones on the ternary phase diagram of the heavy oil emulsion system, which is represented by a solid line in the ternary phase diagram; y 2 represents the boundary function between the second and third zones of the heavy oil emulsion system, which is represented by a dotted line in the ternary phase diagram; y 3 represents the boundary function of the third and fourth zones of the heavy oil emulsion system, which is represented by a dotted line combined with dots in the ternary phase diagram.

10. A method for drawing a ternary phase diagram of a heavy oil emulsion according to any one of claims 1 to 9, characterized in that: Determine the phase state and dispersed phase concentration under given conditions; including: Given the ratio of heavy oil to mineralized water and the mass concentration of the viscosity reducer, the point corresponding to this condition in the plane coordinate system is added to the ternary phase diagram of the heavy oil emulsion. The corresponding phase state is determined according to the area where the point is located, and the emulsion concentration value is obtained by interpolation based on the dispersed phase concentration contour line.

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