Performance evaluation method of foaming agent

Abstract

The invention provides a foaming agent performance evaluation method. The method comprises the following steps: preparing a foaming agent solution; starting the multiple light scatterometer, setting operation parameters of the multiple light scatterometer, and stabilizing the multiple light scatterometer with the set operation parameters for a period of time; stirring the foaming agent solution to completely foam the foaming agent to obtain a to-be-detected sample, placing the to-be-detected sample in a sample cell of a multiple light scatterometer which has set operating parameters and is stabilized, detecting the to-be-detected sample according to the set operating parameters, and collecting spectral signals; and converting the spectral signal into image information, and evaluating the performance of the foaming agent based on the spectral signal and the image information. According to the method, based on multiple light scattering, the comprehensive performance of the foaming power and the stability of the foaming agent can be evaluated, and the evaluation accuracy is improved.

Description

Technical Field

[0001] The invention relates to a performance evaluation method for a foaming agent, belonging to the technical field of oil and gas production engineering. Background Art

[0002] With the continuous development of shale gas development technology, foam drainage and gas production technology has gradually been applied to shale gas development. The effect of foam drainage and gas production technology mainly depends on the type and performance of the foaming agent. Foaming agents are divided into foaming agents and defoaming agents, mainly surfactants. Foaming agents are the main components of foaming agents and play a decisive role in the quality of foaming technology. Therefore, it is necessary to analyze and evaluate the performance of foaming agents and quantify their performance through some indicators, mainly including foaming power, stability, liquid carrying rate, etc., to ensure that the foaming agent plays a role in reducing wellbore liquid accumulation and improving drainage and gas production efficiency during use. Therefore, the quantitative evaluation of foaming agent performance is very important.

[0003] At present, the evaluation methods of foaming agents for foam drainage and gas production include general property evaluation, surface (interface) tension evaluation, foaming power evaluation, foam dynamic performance evaluation, thermal stability evaluation and thermal stability evaluation, among which foaming power and foam dynamic performance are the most critical. At present, the foaming power is mainly evaluated by Roche Mills foam tester, and the foam dynamic performance is evaluated by foam dynamic performance evaluation device, but it cannot meet the performance evaluation of foaming agents under conditions above 90°C, and mainly relies on naked eyes for judgment, which has large errors and great limitations in application.

[0004] CN107817190B discloses a method for evaluating the comprehensive performance of foam. The method establishes a comprehensive evaluation model for foams of different reservoir types. However, the method mainly focuses on the calculation of foaming ability and cannot evaluate stability and liquid carrying capacity.

[0005] CN104678059B discloses a system and method for evaluating the foaming power and dynamic performance of a foaming agent. The system and method can evaluate the performance of a foaming agent at a temperature above 90°C from a macroscopic perspective. However, the evaluation process using the system and method still mainly relies on visual observation.

[0006] CN110716016B discloses a method for evaluating foam stability. This method evaluates the foaming power and stability of foam by visual observation, but is greatly affected by the external environment and the obtained data is not accurate enough.

[0007] Therefore, developing a new performance evaluation method for foaming agents is still one of the problems to be solved urgently in this field. Summary of the invention

[0008] In order to solve the above technical problems, the purpose of the present invention is to provide a method for evaluating the performance of a foaming agent. The method is based on multiple light scattering and can evaluate the comprehensive performance of the foaming power and stability of the foaming agent, thereby improving the accuracy of the evaluation.

[0009] In order to achieve the above object, the present invention provides a method for evaluating the performance of a foaming agent, which comprises the following steps:

[0010] (1) preparing a foaming agent solution;

[0011] (2) starting the multiple light scattering instrument, setting the operating parameters of the multiple light scattering instrument, and stabilizing the multiple light scattering instrument with the set operating parameters for a period of time;

[0012] (3) stirring the foaming agent solution obtained in step (1) to completely foam the foaming agent to obtain a sample to be tested, placing the sample to be tested in a sample cell of a multiple light scattering instrument after the operating parameters have been set and stabilized, testing the sample to be tested according to the operating parameters set in step (2), and collecting spectral signals;

[0013] (4) converting the spectral signal obtained in step (3) into image information, and evaluating the performance of the foaming agent based on the spectral signal and the image information;

[0014] The evaluation of the performance of the foaming agent at least includes: calculating the comprehensive performance index of the foaming agent by a comprehensive performance evaluation formula of foaming power and stability; the comprehensive performance evaluation formula of foaming power and stability is:

[0015] N=B×t

[0016] Wherein, N is the comprehensive performance index of the foaming agent; B is the average value of the initial (ie, first scan) backscattered light intensity of the sample to be tested, %; t is the time when the foam of the sample to be tested completely disappears, h.

[0017] In the above method, preferably, in step (1), the foaming agent solution is prepared in the following manner: adding the foaming agent to water and stirring at a stirring speed of 250-350 r / min for 25-35 min to obtain the foaming agent solution. The concentration of the foaming agent solution can be conventionally adjusted by a person skilled in the art based on different usage requirements, and the present invention does not specifically limit it. More preferably, the water used to prepare the foaming agent solution is simulated formation water. The simulated formation water can be conventionally prepared by a person skilled in the art according to actual conditions.

[0018] In the above method, preferably, in step (2), the operating parameters of the multiple light scattering instrument include: detection temperature is 25°C; detection position is the sample pool of the multiple light scattering instrument; scanning period is 4-6h; scanning frequency is 1min / time.

[0019] In the above method, preferably, in step (2), the multiple light scattering instrument with set operating parameters is stabilized for 30-40 minutes.

[0020] In the above method, preferably, in step (3), the foaming agent solution obtained in step (1) is stirred to completely foam the foaming agent at a stirring speed of 2500-3500 r / min and a stirring time of 30-60 s.

[0021] In the above method, preferably, step (3) further comprises: dividing the sample to be tested into two parts, wherein one part is placed in an oven as a control group, and the other part is placed in a sample pool of the multiple light scattering instrument for detection; and the volume of the sample to be tested placed in the oven is the same as that of the sample to be tested placed in the sample pool of the multiple light scattering instrument, and the temperature of the oven is the same as the detection temperature of the multiple light scattering instrument; and observing the foam changes of the control group.

[0022] It should be noted that the scanning period of the above-mentioned multiple light scattering instrument can be adjusted according to the defoaming time of the control group.

[0023] In the above method, preferably, in step (3), the spectral signal includes transmitted light intensity (T) and backscattered light intensity (BS).

[0024] In the above method, preferably, in step (4), the time for the foam of the sample to be tested in the comprehensive performance evaluation formula for foaming power and stability completely disappears is the time for the foam of the control group to completely disappear obtained by observing the foam changes of the control group.

[0025] In the above method, preferably, in step (4), the image information includes a curve of backscattered light intensity (BS) versus scanning time and scanning height, a curve of transmitted light intensity (T) versus scanning time and scanning height, and a relationship diagram of stability index (TSI) and scanning time; wherein the stability index is calculated by the following formula:

[0026]

[0027] Where, TSI is the stability index; x i is the average backscattered light intensity of each scan, %; x s For x i The average value, %; n is the number of scans.

[0028] In the above method, preferably, in step (4), evaluating the performance of the foaming agent further comprises: analyzing the dynamic change of the foam through the curve of the change of backscattered light intensity (BS) with scanning time and scanning height and the curve of the change of transmitted light intensity (T) with scanning time and scanning height, obtaining the liquid separation process of the sample to be tested, and obtaining the liquid separation half-life of the foaming agent solution by analyzing the curve. More preferably, the liquid separation half-life of the foaming agent solution is obtained in the following manner: in the curve of the change of transmitted light intensity (T) with scanning time and scanning height, when the scanning height is less than 1 / 2 of the total height, the transmitted light intensity becomes obviously stronger, and the scanning time at this time is the liquid separation half-life.

[0029] In the above method, preferably, in step (4), evaluating the performance of the foaming agent further includes: analyzing the foaming power of the foaming agent solution through a curve of backscattered light intensity (BS) changing with scanning time and scanning height and a curve of transmitted light intensity (T) changing with scanning time and scanning height.

[0030] In some specific embodiments of the present invention, preferably, the strength of the foaming power of the foaming agent solution is obtained in the following manner: in the variation curve of backscattered light intensity with scanning time and scanning height, if the backscattered light intensity is very high (i.e., the backscattered light intensity ≥ 3%) at the initial stage of scanning (i.e., the scanning image with a scanning time of 0-5 min), it indicates that the foaming power of the foaming agent solution meets the requirements; if the backscattered light intensity is very low (i.e., the backscattered light intensity < 3%) at the initial stage of scanning (i.e., the scanning image with a scanning time of 0-5 min), it indicates that the foaming power of the foaming agent solution is weak; and / or, in the variation curve of transmitted light intensity with scanning time and scanning height, if the transmitted light intensity is very low (i.e., the transmitted light intensity < 10%) at the initial stage of scanning (i.e., the scanning image with a scanning time of 0-5 min), it indicates that the foaming power of the foaming agent solution is strong; and / or, in the variation curve of transmitted light intensity with scanning time and scanning height, if the transmitted light intensity remains substantially unchanged as the scanning height increases, it indicates that the foaming power of the foaming agent solution is strong.

[0031] In the above method, preferably, in step (4), evaluating the performance of the foaming agent further comprises: analyzing the strength of the foam stability of the foaming agent solution through a relationship diagram between the stability index (TSI) and the scanning time.

[0032] In the above method, preferably, in step (4), when the foaming agent comprehensive performance index N is greater than 2, more preferably greater than 10, the foaming agent has good comprehensive performance of foaming power and stability. The larger the value of the foaming agent comprehensive performance index, the higher the comprehensive performance of the foaming agent.

[0033] According to a specific embodiment of the present invention, preferably, the above method further comprises step (5): repeating step (3) and step (4), and then repeatedly evaluating the performance of the foaming agent, and verifying the evaluation result.

[0034] The present invention provides a performance evaluation method for a foaming agent. The method of the present invention is based on the principle of multiple light scattering, analyzes the dynamic changes of foam through image information, and can monitor the foam changes in real time. At the same time, the method of the present invention creatively proposes a comprehensive performance evaluation formula for foaming power and stability in combination with the microscopic mechanism. The comprehensive performance index of the foaming agent can be calculated by the formula, and then the comprehensive performance of the foaming power and stability of the foaming agent can be more accurately evaluated. The method of the present invention can be repeatedly tested, and can provide support for the accuracy of the performance evaluation of the foaming agent.

[0035] The technical solution of the present invention has at least the following beneficial effects:

[0036] 1. The method of the present invention is simple to operate, and adopts a multiple light scattering instrument for detection. At the same time, the foam changes of the control group can be observed auxiliaryly, which can effectively avoid experimental errors caused by subjective judgment of experimenters and objective factors. The detection can be repeated to improve the accuracy of the detection results.

[0037] 2. The method of the present invention can analyze the dynamic changes of foam through the curves of backscattered light intensity (BS) changing with scanning time and scanning height and the curves of transmitted light intensity (T) changing with scanning time and scanning height, obtain the liquid separation process of the sample to be tested, and analyze the liquid separation half-life of the foaming agent solution, and at the same time analyze the strength of the foaming power of the foaming agent solution; and through the relationship diagram of the stability index (TSI) and the scanning time, the strength of the foam stability of the foaming agent solution can be analyzed.

[0038] 3. The method of the present invention can analyze the foam change law of the sample to be tested and obtain the foaming ability and stability of the foaming agent through the change curve of backscattered light intensity (BS) versus scanning time and scanning height, the change curve of transmitted light intensity (T) versus scanning time and scanning height, the relationship diagram of stability index (TSI) and scanning time, and the comprehensive performance index of the foaming agent, and can be used to evaluate the performance of foaming agents under different types and construction environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a curve showing the variation of backscattered light intensity with scanning time and scanning height obtained in Example 1.

[0040] Figure 2 This is a curve showing the variation of the transmitted light intensity with the scanning time and scanning height obtained in Example 1.

[0041] Figure 3 This is a relationship diagram between the stability index and the scanning time obtained in Example 1.

[0042] Figure 4 This is a curve showing the variation of backscattered light intensity with scanning time and scanning height obtained in Example 2.

[0043] Figure 5 This is the curve of the transmitted light intensity obtained in Example 2 as a function of scanning time and scanning height.

[0044] Figure 6 This is a relationship diagram between the stability index and the scanning time obtained in Example 2. DETAILED DESCRIPTION

[0045] In order to have a clearer understanding of the technical features, purposes and beneficial effects of the present invention, the technical solution of the present invention is now described in detail below, but it should not be construed as limiting the applicable scope of the present invention.

[0046] Example 1

[0047] This embodiment provides a method for evaluating the performance of a foaming agent, which comprises the following steps:

[0048] (1) Preparation of foaming agent solution: First prepare a solution with a mineralization degree of 2×10 4 mg / L simulated formation water, add the foaming agent QP-1 to be evaluated into the simulated formation water, and stir it at a stirring speed of 300r / min for 30min using a magnetic stirrer to obtain a foaming agent solution with a mass fraction of 0.5% of the foaming agent;

[0049] (2) Start the multiple light scattering instrument (Turbiscan stability analyzer from ALV-GmbH, Germany) and preheat for 40 min. Then set the operating parameters of the multiple light scattering instrument. The operating parameters are as follows: the detection temperature is 25°C; the detection position is the sample pool of the multiple light scattering instrument; the scanning cycle (i.e., scanning time) is 4 h, and the scanning frequency is 1 min / time. The multiple light scattering instrument with the set operating parameters is stabilized for 30 min.

[0050] (3) placing the foaming agent solution obtained in step (1) in a Wu Yin mixer, stirring at a stirring speed of 3000 r / min for 30 seconds to completely foam the foaming agent, and obtaining a sample to be tested, and dividing the sample to be tested into two parts; one of the parts is quickly placed in a sample pool, and the sample pool is placed in an oven, as a control group; the other part is quickly placed in a sample pool of a multiple light scattering instrument after the operating parameters are set and stabilized, and the sample to be tested is tested according to the operating parameters set in step (2), and spectral signals are collected, wherein the spectral signals include the intensity of transmitted light (T) and the intensity of backscattered light (BS); and the volume of the sample to be tested placed in the oven is the same as that of the sample to be tested placed in the sample pool of the multiple light scattering instrument, and the temperature of the oven is the same as the detection temperature of the multiple light scattering instrument; and the foam changes of the control group are observed;

[0051] (4) converting the spectral signal obtained in step (3) into image information, and evaluating the performance of the foaming agent based on the spectral signal and the image information;

[0052] The performance evaluation of the foaming agent includes: calculating the comprehensive performance index of the foaming agent by a comprehensive performance evaluation formula of foaming power and stability; the comprehensive performance evaluation formula of foaming power and stability is:

[0053] N=B×t

[0054] Wherein, N is the comprehensive performance index of the foaming agent; B is the average value of the initial (i.e., the first scan) backscattered light intensity of the sample to be tested, %; t is the time for the foam of the sample to be tested to completely disappear, h, which is the time for the foam of the control group to completely disappear obtained by observing the foam changes of the control group;

[0055] When the comprehensive performance index N of the foaming agent is greater than 10, the foaming agent has good comprehensive performance of foaming power and stability;

[0056] The image information includes a curve of backscattered light intensity (BS) versus scanning time and scanning height, a curve of transmitted light intensity (T) versus scanning time and scanning height, and a relationship diagram of stability index (TSI) and scanning time; wherein the stability index is calculated by the following formula:

[0057]

[0058] Where, TSI is the stability index; x i is the average backscattered light intensity of each scan, %; x s For x i The average value, %; n is the number of scans;

[0059] The performance evaluation of the foaming agent also includes: analyzing the dynamic change of the foam through the curve of the backscattered light intensity (BS) versus the scanning time and scanning height and the curve of the transmitted light intensity (T) versus the scanning time and scanning height, obtaining the liquid separation process of the sample to be tested, and obtaining the liquid separation half-life of the foaming agent solution through the analysis of the curve;

[0060] The performance evaluation of the foaming agent further includes: analyzing the foaming power of the foaming agent solution through the curve of the backscattered light intensity (BS) changing with the scanning time and the scanning height and the curve of the transmitted light intensity (T) changing with the scanning time and the scanning height;

[0061] The performance evaluation of the foaming agent further includes: analyzing the foam stability of the foaming agent solution through a relationship diagram between the stability index (TSI) and the scanning time.

[0062] The evaluation results of this embodiment are as follows:

[0063] The average value B of the initial backscattered light intensity of the sample to be tested obtained in this embodiment is 4%, the time for the foam of the sample to be tested to completely disappear is 4 hours, and the calculated foaming agent comprehensive performance index is 16. The larger the value of the foaming agent comprehensive performance index, the higher the comprehensive performance of the foaming agent. The foaming agent comprehensive performance index of this embodiment is 16, which proves that the foaming agent evaluated in this embodiment has good comprehensive performance of foaming power and stability.

[0064] Figure 1 The backscattered light intensity (BS) obtained in this embodiment varies with the scanning time and scanning height. Figure 1 It can be seen that in the early stage of foaming, the backscattered light intensity at the bottom and top of the sample pool basically did not change, and the foam was distributed relatively evenly. With the increase of time, the backscattered light intensity gradually increased, and the bottom light intensity growth rate was higher than that of the top. After 30 minutes, an obvious peak appeared at the bottom, and no trough appeared, indicating that the foam was evenly distributed and stable.

[0065] Figure 2 The curve of the transmitted light intensity (T) obtained in this embodiment versus the scanning time and scanning height. Figure 2 It can be seen that the foaming agent has good light transmittance (T ≥ 0.2%) after foaming, so it can be used with Figure 1Combined analysis is performed to analyze the dynamic changes of the foam, obtain the liquid separation process of the sample to be tested, and analyze the liquid separation half-life of the foaming agent solution. Through the change in light intensity, it can be seen that the initial transmitted light intensity is low, and there is basically no change from the bottom to the top, indicating that the foam is dense and evenly distributed. As time goes on, the transmitted light intensity increases, and a peak appears at the bottom, indicating that the total amount of foam is reduced and liquid is precipitated at the bottom, further proving that the generated foam has strong stability. When the scanning height is below 1 / 2 of the total height, the transmitted light intensity becomes significantly stronger, and the scanning time at this time is the liquid separation half-life, and the liquid separation half-life of the foaming agent solution of this embodiment is 1.5h.

[0066] Figure 3 is a graph showing the relationship between the stability index and the scanning time obtained in Example 1. Figure 3 It can be seen that the foaming agent stability index gradually increases with the increase of detection time, indicating that the foam stability of the foaming agent solution becomes worse and worse after foaming, and the foam gradually decreases.

[0067] In this embodiment, Figure 1 In the scanning process, when the foaming agent is fully foamed, at the initial scanning stage (i.e., the scanning image with a scanning time of 0-5 min), the backscattered light intensity meets the requirement (i.e., the backscattered light intensity is ≥3%), indicating that the foaming agent solution has a strong foaming power; at the same time, Figure 2 In the initial stage of scanning (i.e., the scanning image with a scanning time of 0-5min), the transmitted light intensity is very low (i.e., the transmitted light intensity <10%), indicating that the foam is very dense and the foaming power of the foaming agent solution is strong; and as the scanning height increases, the transmitted light intensity remains basically unchanged, indicating that the foam is evenly distributed and the foaming power of the foaming agent solution is strong.

[0068] In summary, the foaming agent evaluated in this example is 2×10 4 It has good performance in formation water with a mineralization of 1.5 mg / L.

[0069] Example 2

[0070] This embodiment provides a method for evaluating the performance of a foaming agent, which comprises the following steps:

[0071] (1) Preparation of foaming agent solution: First prepare a solution with a mineralization degree of 2×10 4 mg / L simulated formation water, add the foaming agent QP-2 to be evaluated into the simulated formation water, and stir for 30 min at a stirring speed of 300 r / min using a magnetic stirrer to obtain a foaming agent solution with a mass fraction of 0.5% of the foaming agent;

[0072] (2) Start the multiple light scattering instrument (Turbiscan stability analyzer from ALV-GmbH, Germany) and preheat for 40 min. Then set the operating parameters of the multiple light scattering instrument. The operating parameters are as follows: the detection temperature is 25°C; the detection position is the sample pool of the multiple light scattering instrument; the scanning cycle (i.e., scanning time) is 4 h, and the scanning frequency is 1 min / time. The multiple light scattering instrument with the set operating parameters is stabilized for 30 min.

[0073] (3) placing the foaming agent solution obtained in step (1) in a Wu Yin mixer, stirring at a stirring speed of 3000 r / min for 30 seconds to completely foam the foaming agent, and obtaining a sample to be tested, and dividing the sample to be tested into two parts; one of the parts is quickly placed in a sample pool, and the sample pool is placed in an oven, as a control group; the other part is quickly placed in a sample pool of a multiple light scattering instrument after the operating parameters are set and stabilized, and the sample to be tested is tested according to the operating parameters set in step (2), and spectral signals are collected, wherein the spectral signals include the intensity of transmitted light (T) and the intensity of backscattered light (BS); and the volume of the sample to be tested placed in the oven is the same as that of the sample to be tested placed in the sample pool of the multiple light scattering instrument, and the temperature of the oven is the same as the detection temperature of the multiple light scattering instrument; and the foam changes of the control group are observed;

[0074] (4) converting the spectral signal obtained in step (3) into image information, and evaluating the performance of the foaming agent based on the spectral signal and the image information;

[0075] The performance evaluation of the foaming agent includes: calculating the comprehensive performance index of the foaming agent by a comprehensive performance evaluation formula of foaming power and stability; the comprehensive performance evaluation formula of foaming power and stability is:

[0076] N=B×t

[0077] Wherein, N is the comprehensive performance index of the foaming agent; B is the average value of the initial (i.e., the first scan) backscattered light intensity of the sample to be tested, %; t is the time for the foam of the sample to be tested to completely disappear, h, which is the time for the foam of the control group to completely disappear obtained by observing the foam changes of the control group;

[0078] When the comprehensive performance index N of the foaming agent is greater than 10, the foaming agent has good comprehensive performance of foaming power and stability;

[0079] The image information includes a curve of backscattered light intensity (BS) versus scanning time and scanning height, a curve of transmitted light intensity (T) versus scanning time and scanning height, and a relationship diagram of stability index (TSI) and scanning time; wherein the stability index is calculated by the following formula:

[0080]

[0081] Where, TSI is the stability index; x i is the average backscattered light intensity of each scan, %; x s For x i The average value, %; n is the number of scans;

[0082] The performance evaluation of the foaming agent also includes: analyzing the dynamic change of the foam through the curve of the backscattered light intensity (BS) versus the scanning time and scanning height and the curve of the transmitted light intensity (T) versus the scanning time and scanning height, obtaining the liquid separation process of the sample to be tested, and obtaining the liquid separation half-life of the foaming agent solution through the analysis of the curve;

[0083] The performance evaluation of the foaming agent further includes: analyzing the foaming power of the foaming agent solution through the curve of the backscattered light intensity (BS) changing with the scanning time and the scanning height and the curve of the transmitted light intensity (T) changing with the scanning time and the scanning height;

[0084] The performance evaluation of the foaming agent further includes: analyzing the foam stability of the foaming agent solution through a relationship diagram between the stability index (TSI) and the scanning time.

[0085] The evaluation results of this embodiment are as follows:

[0086] The average value B of the initial backscattered light intensity of the sample to be tested obtained in this embodiment is 80%, the time for the foam of the sample to be tested to completely disappear is 2 hours, and the calculated foaming agent comprehensive performance index is 160. The larger the value of the foaming agent comprehensive performance index, the higher the comprehensive performance of the foaming agent. The foaming agent comprehensive performance index of this embodiment is 160, indicating that the performance of the foaming agent is very good.

[0087] Figure 4 The backscattered light intensity (BS) obtained in this embodiment varies with the scanning time and scanning height. Figure 4 It can be seen that in the early stage of foaming, the backscattered light intensity at the bottom and top of the sample pool basically did not change, and the foam was distributed relatively evenly. With the increase of time, the backscattered light intensity gradually increased, and the bottom light intensity growth rate was higher than that of the top. After 30 minutes, an obvious peak appeared at the bottom, and no trough appeared, indicating that the foam was evenly distributed and stable.

[0088] Figure 5 The curve of the transmitted light intensity (T) obtained in this embodiment versus the scanning time and scanning height. Figure 5 It can be seen that the light transmittance of the foaming agent is poor after foaming (T approaches 0%). As time goes by, the intensity of the transmitted light gradually increases, and the intensity increases rapidly in the middle of the scan. Figure 4Combined analysis is performed to analyze the dynamic changes of the foam, obtain the liquid separation process of the sample to be tested, and analyze the liquid separation half-life of the foaming agent solution. Through the change in light intensity, it can be seen that the initial transmitted light intensity is low, and there is basically no change from the bottom to the top, indicating that the foam is very dense and evenly distributed. As time goes on, the transmitted light intensity increases, and a peak appears in the middle, indicating that the total amount of foam is reduced and liquid is precipitated. When the scanning height is below 1 / 2 of the total height, the transmitted light intensity becomes significantly stronger, and the scanning time at this time is the liquid separation half-life. The liquid separation half-life of the foaming agent solution of this embodiment is 1h.

[0089] Figure 6 is a graph showing the relationship between the stability index and the scanning time obtained in this embodiment. Figure 6 It can be seen that the foaming agent stability index gradually increases with the increase of detection time, indicating that the foam stability of the foaming agent solution becomes worse and worse after foaming, and the foam gradually decreases.

[0090] In this embodiment, Figure 4 and Figure 5 In the initial scanning stage (i.e., the scanning image with a scanning time of 0-5 min), the transmitted light intensity is very low (i.e., the transmitted light intensity <10%), and the backscattered light is very strong (i.e., the backscattered light intensity ≥3%), indicating that the foam is very dense and the foaming power of the foaming agent solution is strong; with the increase of the scanning height, a peak appears in the transmitted light intensity, and the light intensity change is concentrated in the middle of the sample pool, and the change is very obvious, indicating that although the foaming ability of the foaming agent is very strong, the distribution is uneven; with the increase of the scanning height, the light intensity change gradually tends to be stable, indicating that the foam in the upper and middle parts is evenly distributed.

[0091] In summary, the foaming agent evaluated in this example is 2×10 4 It has good performance in formation water with a mineralization degree of mg / L, and the foaming ability of the foaming agent is very strong.

Claims

1. A method for evaluating the performance of a foaming agent, comprising the following steps: (1) preparing a foaming agent solution; (2) starting the multiple light scattering instrument, setting the operating parameters of the multiple light scattering instrument, and stabilizing the multiple light scattering instrument with the set operating parameters for a period of time; (3) stirring the foaming agent solution obtained in step (1) to completely foam the foaming agent to obtain a sample to be tested, placing the sample to be tested in a sample cell of a multiple light scattering instrument after the operating parameters have been set and stabilized, testing the sample to be tested according to the operating parameters set in step (2), and collecting spectral signals; (4) converting the spectral signal obtained in step (3) into image information, and evaluating the performance of the foaming agent based on the spectral signal and the image information; The evaluation of the performance of the foaming agent at least includes: calculating the comprehensive performance index of the foaming agent by a comprehensive performance evaluation formula of foaming power and stability, wherein the comprehensive performance evaluation formula of foaming power and stability is: NB×t Wherein, N is the comprehensive performance index of the foaming agent; B is the average value of the initial backscattered light intensity of the sample to be tested, %; t is the time when the foam of the sample to be tested completely disappears, h.

2. The method for evaluating the performance of a foaming agent according to claim 1, wherein: In step (1), the foaming agent solution is prepared in the following manner: adding the foaming agent into water and stirring at a stirring speed of 250-350 r / min for 25-35 min to obtain the foaming agent solution.

3. The method for evaluating the performance of a foaming agent according to claim 1, wherein: In step (2), the operating parameters of the multiple light scattering instrument include: detection temperature is 25° C.; detection position is the sample pool of the multiple light scattering instrument; scanning cycle is 4-6 hours; scanning frequency is 1 min / time.

4. The method for evaluating the performance of a foaming agent according to claim 1, wherein: In step (2), the multiple light scattering instrument with set operating parameters is stabilized for 30-40 minutes.

5. The method for evaluating the performance of a foaming agent according to claim 1, wherein: In step (3), the foaming agent solution obtained in step (1) is stirred so that the foaming agent is completely foamed at a stirring speed of 2500-3500 r / min and a stirring time of 30-60 s.

6. The method for evaluating the performance of a foaming agent according to claim 1, wherein: Step (3) further comprises: dividing the sample to be tested into two parts, wherein one part is placed in an oven as a control group, and the other part is placed in a sample pool of the multiple light scattering instrument for detection; the volume of the sample to be tested placed in the oven is the same as the volume of the sample to be tested placed in the sample pool of the multiple light scattering instrument, and the temperature of the oven is the same as the detection temperature of the multiple light scattering instrument; and observing the foam changes of the control group.

7. The method for evaluating the performance of a foaming agent according to claim 1, wherein: In step (3), the spectral signal includes the intensity of transmitted light and the intensity of backscattered light.

8. The method for evaluating the performance of a foaming agent according to claim 6, wherein: In step (4), the time for the foam of the sample to be tested in the comprehensive performance evaluation formula for foaming power and stability is the time for the foam of the control group to completely disappear obtained by observing the foam changes of the control group.

9. The method for evaluating the performance of a foaming agent according to claim 1, wherein: In step (4), the image information includes a curve showing a change in backscattered light intensity versus scanning time and scanning height, a curve showing a change in transmitted light intensity versus scanning time and scanning height, and a graph showing a relationship between a stability index and scanning time; wherein the stability index is calculated using the following formula: Where, TSI is the stability index; x i is the average backscattered light intensity of each scan, %; x s For x i The average value, %; n is the number of scans.

10. The method for evaluating the performance of a foaming agent according to claim 9, wherein: In step (4), evaluating the performance of the foaming agent further comprises: analyzing the dynamic change of the foam through the curve of the change of backscattered light intensity with scanning time and scanning height and the curve of the change of transmitted light intensity with scanning time and scanning height, obtaining the liquid precipitation process of the sample to be tested, and obtaining the liquid precipitation half-life of the foaming agent solution through the analysis of the curve; Preferably, the liquid precipitation half-life of the frother solution is obtained in the following manner: in the curve of the variation of the transmitted light intensity with the scanning time and the scanning height, when the scanning height is below 1 / 2 of the total height, the transmitted light intensity becomes obviously stronger, and the scanning time at this time is the liquid precipitation half-life.

11. The method for evaluating the performance of a foaming agent according to claim 9, wherein: In step (4), evaluating the performance of the foaming agent further includes: analyzing the foaming power of the foaming agent solution through the curve of the backscattered light intensity changing with the scanning time and the scanning height and the curve of the transmitted light intensity changing with the scanning time and the scanning height; Preferably, in step (4), evaluating the performance of the foaming agent further comprises: analyzing the strength of the foam stability of the foaming agent solution through a relationship diagram between the stability index and the scanning time.

12. The method for evaluating the performance of a foaming agent according to claim 1, wherein: In step (4), when the comprehensive performance index N of the foaming agent is greater than 2, the foaming agent has good comprehensive performance of foaming power and stability.

13. The method for evaluating the performance of a foaming agent according to claim 1, wherein: The method further comprises step (5): repeating step (3) and step (4), and then repeatedly evaluating the performance of the foaming agent, and verifying the evaluation result.

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