Method for quantitatively describing scaling degree of produced wells in ASP flooding

Abstract

The present application discloses a method for quantitatively describing the scaling degree of production wells in a ternary composite flooding, including: using the pH value, calcium and magnesium ion concentrations, and carbonate ion concentration as characterization parameters for the scaling degree of production wells in a ternary block, and determining the weight coefficients of each characterization parameter; establishing correlation formulas between the abnormal scaling factor ratios in the ternary block and the pH value, calcium and magnesium ion concentrations, and carbonate ion concentration respectively; establishing a calculation formula for quantitatively describing the scaling degree of a single production well in the block based on the weight coefficients and the correlation formulas; solving the problem that the existing scaling prediction method for ternary oil wells cannot quantitatively describe the scaling degree of the block.

Description

Technical Field

[0001] The present disclosure relates to the field of scale prevention and removal in polymer flooding, and specifically describes a method for describing the scale formation degree of polymer flooding production wells. Background Art

[0002] The statements in this section only provide background information related to the present disclosure and do not constitute prior art.

[0003] When the polymer flooding production wells enter different scale formation stages, it is necessary to conduct a quantitative evaluation study on the scale formation degree of the block to guide the reasonable chemical dosing and the timing of stopping and reducing the drug for individual wells.

[0004] However, the current scale prediction method for polymer oil wells has a low coincidence rate of scale prediction because it cannot quantitatively describe the scale formation degree of the block, and cannot accurately guide the reasonable chemical dosing amount and the timing of stopping and reducing the drug for on-site individual wells.

[0005] It should be noted that the information disclosed in the above background art section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute prior art. Summary of the Invention

[0006] In view of this, the present disclosure provides a method for quantitatively describing the scale formation degree of polymer flooding production wells, which solves the problem that the existing scale prediction method for polymer oil wells cannot quantitatively describe the scale formation degree of the block.

[0007] To achieve the above invention objective, the method for quantitatively describing the scale formation degree of polymer flooding production wells includes:

[0008] Using the pH value, calcium and magnesium ion concentrations, and carbonate ion concentration as the characterization parameters for the scale formation degree of polymer flooding production wells in the block, and determining the weight coefficients of each characterization parameter;

[0009] Establishing the correlation formulas between the abnormal scale formation ratio of the block and the pH value, calcium and magnesium ion concentrations, and carbonate ion concentration respectively;

[0010] Establishing a calculation formula for quantitatively describing the scale formation degree of individual wells in the block based on the weight coefficients and the correlation formulas.

[0011] In the embodiment of the present disclosure, the method for determining the weight coefficient of the pH value includes:

[0012] Obtaining the pH value range of the scale formation wells in the polymer flooding production wells in the block, and dividing the pH value range into a set number of intervals;

[0013] For the scale formation wells, according to the initial stage of scale formation, the middle stage of scale formation, and the late stage of scale formation, respectively counting the number of wells with abnormal scale formation causes in each interval of the pH value, and the total number of wells with abnormal scale formation causes corresponding to the initial stage of scale formation, the middle stage of scale formation, and the late stage of scale formation respectively;

[0014] The ratio of the well instance to the corresponding total well instances is the scale factor abnormal well instance ratio for each of the intervals;

[0015] Calculate the absolute value of the difference in the scale factor abnormal well instance ratios between adjacent intervals, and take the average value of the absolute values as the scale factor abnormal well instance ratio fluctuation value;

[0016] The average value of the scale factor abnormal well instance ratio fluctuation values in the initial scaling stage, the middle scaling stage, and the late scaling stage is the influence weight of the pH value.

[0017] In an embodiment of the present disclosure, the method for establishing the correlation formula between the scale factor abnormal ratio and the pH value includes:

[0018] Statistically analyze the scale factor abnormal well instance ratios occurring in each of the intervals within the pH value range of the ternary block, plot the influence curve of the pH value on the scale factor abnormal well instance ratio with the average value of the interval pH values as the abscissa and the corresponding scale factor abnormal well instance ratio as the ordinate, and obtain the correlation formula.

[0019] In an embodiment of the present disclosure, the sum of the respective correlation formulas multiplied by the corresponding weight coefficients is the calculation formula for quantitatively describing the scaling degree of a single well of the produced wells in the block.

[0020] In an embodiment of the present disclosure, the set number of the intervals is 10.

[0021] The present disclosure has the following beneficial effects:

[0022] The method of the present disclosure for quantitatively describing the scaling degree of produced wells in a ternary composite flooding process first determines the pH value, calcium and magnesium ion concentrations, and carbonate ion concentrations that mainly affect scaling as the basis. Then, by calculating the weight coefficients of the pH value, calcium and magnesium ion concentrations, and carbonate ion concentrations on the scaling degree of the produced wells in the ternary composite flooding process respectively, and establishing correlation formulas between the pH value, calcium and magnesium ion concentrations, and carbonate ion concentrations and the scale factor abnormal ratio respectively. Since the scale factor abnormal ratio represents the degree of scaling, finally, the calculation formula for quantitatively describing the scaling degree of the produced wells in the ternary composite flooding process can be obtained by using the weight coefficients and the correlation formulas, thereby effectively solving the problem that the existing scaling prediction method for ternary oil wells cannot quantitatively describe the scaling degree of the block. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Through the description of the embodiments of the present disclosure with reference to the following drawings, the above and other objects, features, and advantages of the present disclosure will become clearer. In the drawings:

[0024] Figure 1 is the flowchart of the method of the present disclosure for quantitatively describing the scaling degree of produced wells in a ternary composite flooding process;

[0025] Figure 2 is the relationship curve between the pH value of the strong base block and the abnormal scale factor in the embodiments of the present disclosure;

[0026] Figure 3 is the relationship curve between the calcium and magnesium ion concentration of the strong base block and the abnormal scale factor in the embodiments of the present disclosure;

[0027] Figure 4 is the relationship curve between the carbonate ion concentration of the strong base block and the abnormal scale factor in the embodiments of the present disclosure. Specific Embodiments

[0028] The following describes the present disclosure based on embodiments. However, it should be noted that the present disclosure is not limited to these embodiments. In the following detailed description of the present disclosure, some specific details are described in detail. However, for the parts that are not described in detail, those skilled in the art can also fully understand the present disclosure.

[0029] At the same time, unless the context clearly requires otherwise, words such as "including" and "comprising" in the entire specification and claims should be interpreted as having an inclusive meaning rather than an exclusive or exhaustive meaning; that is, it is the meaning of "including but not limited to".

[0030] In on-site production, the applicant of the present disclosure tracked 4 ternary blocks, 805 oil wells, and 75,000 single wells throughout the process for 7 consecutive years, and conducted chemical tests on the produced fluids of each ternary production well for items such as pH value, calcium and magnesium ion concentration, carbonate ion concentration, chloride ion concentration, sulfate ion concentration, and salinity, etc., to obtain relevant data. Then, statistical analysis and law finding and other research work were carried out on these data, and combined with previous scaling experience judgments, parameters that can to a certain extent characterize the injection status of the ternary displacement fluid and the severity of oil well scaling were searched. Finally, it was determined that the data of pH value, calcium and magnesium ion concentration, and carbonate ion concentration have a major impact on scaling, and the influence of the data of other parameters can be ignored.

[0031] Furthermore, based on the parameters of pH value, calcium and magnesium ion concentration, and carbonate ion concentration, the applicant of the present disclosure provides a quantitative description method for the scaling degree of ternary composite flooding production wells, specifically shown by Figure 1 the flow chart of the disclosed method for quantitatively describing the scaling degree of ternary composite flooding production wells. In Figure 1In the method for quantitatively describing the scaling degree of production wells in a ternary composite flooding, it includes: Step S10: Using the pH value, calcium and magnesium ion concentration, and carbonate ion concentration as the characterization parameters for the scaling degree of production wells in the ternary block, and determining the weight coefficients of each characterization parameter; Step S20: Establishing the correlation formulas between the abnormal scaling factor ratios in the ternary block and the pH value, calcium and magnesium ion concentration, and carbonate ion concentration respectively; Step S30: Establishing a calculation formula for quantitatively describing the scaling degree of a single production well in the block based on the weight coefficients and the correlation formulas.

[0032] Specifically, taking a certain ternary block as an example, each step of the method for quantitatively describing the scaling degree of production wells in a ternary composite flooding of the present disclosure will be further described to help fully understand the technical solution of the method of the present disclosure and the resulting inventive effects. Embodiment

[0033] Step S10: Using the pH value, calcium and magnesium ion concentration, and carbonate ion concentration as the characterization parameters for the scaling degree of production wells in the ternary block, and determining the weight coefficients of each characterization parameter. The specific method is as follows:

[0034] 1. Obtain the pH value range, calcium and magnesium ion concentration range, and carbonate ion concentration range of the scaling wells in the production wells of the ternary block.

[0035] Statistical data of the pH value, calcium and magnesium ion concentration, and carbonate ion concentration of all production wells in the ternary block are obtained, and the data of the pH value, calcium and magnesium ion concentration, and carbonate ion concentration of the production wells that have scaled are selected from them. The distribution ranges of each parameter are statistically obtained to get Table 1.

[0036] Table 1 Distribution ranges of three parameters

[0037] Parameter Name Distribution Range Proportion (%) pH Value 7-12 98.4 Carbonate Ion Concentration 100 - 4000 mg / L 96.5 Calcium and Magnesium Ion Concentration 10 - 120 mg / L 99.7

[0038] 2. Determine the influence weight of the pH value on the scaling of production wells.

[0039] The ternary composite flooding is divided into a strong base block and a weak base block. The difference between the strong base block and the weak base block is the different alkalis injected into the ternary system. The strong base is sodium hydroxide, and the weak base is sodium bicarbonate. Although the scaling trends and scaling degrees of the strong base block and the weak base block are different, the scaling mechanisms are the same.

[0040] In the embodiment of the present disclosure, specifically taking the strong base block as an example, the influence weights of different parameters on the scaling of production wells are determined. The determination process and method for the weak base block are the same as those for the strong base block.

[0041] In the embodiment of the present disclosure, the influence weight of the pH value on the abnormal scaling factor is determined by analyzing the ratio of the number of wells with abnormal scaling factors in different value ranges of the pH value through single-factor analysis.

[0042] The abnormal scaling cause described in the embodiments of the present disclosure refers to the state that may occur when the production well is blocked by scale and cannot operate normally. The proportion a of well times with abnormal scaling cause refers to dividing the pH value, calcium and magnesium ion concentration, and carbonate ion concentration into several intervals respectively at the initial stage, middle stage, and late stage of scaling based on the distribution ranges shown in Table 1, and counting the proportion of well times with abnormal scaling cause in each interval range among the total well times with abnormal scaling cause. Therefore, the scaling degree of the production wells in this ternary block can be characterized by examining the proportion a of well times with abnormal scaling cause, which represents the influence weight of the pH value on the abnormal scaling cause, that is, the influence weight of the pH value on the scaling of production wells. The specific determination method is as follows:

[0043] ① Determine the proportion a of well times with abnormal scaling cause of the production wells in the ternary block at the initial stage, middle stage, and late stage of scaling when the pH value is within the distribution range of 7 - 12.

[0044] In the field of the production wells in the ternary block, the scaling stage is divided into the initial stage, middle stage, and late stage of scaling. Among them, the initial stage of scaling (0.20 - 0.35 PV, the scale is grayish - white, honeycomb - shaped, and the scaling rate is 0.7 - 1 mm / a), the middle stage of scaling (0.35 - 0.50 PV, the scale is brownish - yellow, granular, and the scaling rate is 1 - 2.2 mm / a), and the late stage of scaling (greater than 0.50 PV, the scale is grayish - brown, granular, and the scaling rate is 1.5 - 1 mm / a). The division of the scaling stage corresponding to this embodiment into the initial stage, middle stage, and late stage of scaling is a commonly used technical regulation in the art and is not within the protection scope of the present disclosure.

[0045] The specific scheme adopted in the embodiments of the present disclosure is: within the pH value range of 7 - 12, the pH value is divided into one interval every 0.5 (a total of 10 intervals), and the well times with abnormal scaling cause in this interval at the initial stage, middle stage, and late stage of scaling are counted. The well times with abnormal scaling cause in this interval divided by the total well times with abnormal scaling cause occurring at the corresponding initial stage, middle stage, and late stage of scaling is the proportion a of well times with abnormal scaling cause of the pH value at the initial stage, middle stage, and late stage of scaling, and Table 2 is obtained.

[0046] Table 2 Proportion a of well times with abnormal scaling cause when the pH value is in different value ranges at the initial stage of scaling

[0047]

[0048] Similarly, the proportion a of well times with abnormal scaling cause of the pH value in different value ranges at the middle stage and late stage of scaling can be obtained.

[0049] ② Calculate the average fluctuation value of the proportion of well times with abnormal scaling cause through the above - mentioned proportion a of well times with abnormal scaling cause.

[0050] Based on Table 2, calculate Δa1 = abs(a2 - a1), … Δa9 = abs(a10 - a9);

[0051] average(Δa1…Δa9), and obtain the scaling factor anomaly well proportion fluctuation value 9 at the initial stage of scaling. Similarly, obtain the scaling factor anomaly well proportion fluctuation value 10 at the middle stage of scaling and the scaling factor anomaly well proportion fluctuation value 11 at the late stage of scaling.

[0052] Finally, through the above single-factor analysis of pH value, the average fluctuation value A of the scaling factor anomaly well proportion of the pH value in this ternary block is (9 + 10 + 11) / 3 = 10.

[0053] In the embodiments of the present disclosure, the average fluctuation value of the scaling factor anomaly well proportion of the pH value is used to characterize the influence weight of the pH value on the scaling factor anomaly, and also characterizes the influence weight of the pH value on the scaling of production wells.

[0054] 3. Respectively determine the influence weights of the calcium and magnesium ion concentration range and the carbonate ion concentration on the scaling of production wells.

[0055] In the embodiments of the present disclosure, the same method as determining the influence weight of the pH value on the scaling of production wells is adopted. Continuing through the single-factor analysis method, respectively determine the change of the scaling factor anomaly well proportion in different value ranges of the calcium and magnesium ion concentration range and the carbonate ion concentration, and respectively determine the influence weights of the calcium and magnesium ion concentration range and the carbonate ion concentration on the scaling factor anomaly.

[0056] Among them, the average fluctuation value B of the scaling factor anomaly well proportion under different calcium and magnesium ion concentration conditions of the scaling wells in this ternary block is 10, and the average fluctuation value C of the scaling factor anomaly well proportion under different carbonate ion concentration conditions is 5.

[0057] 4. Calculate the weight coefficients of the influence weights of the pH value, the calcium and magnesium ion concentration, and the carbonate ion concentration on the scaling of production wells in this ternary block.

[0058] Weight coefficient of pH value: 10 / (10 + 10 + 5) = 0.4; Weight coefficient of calcium and magnesium ion concentration: 10 / (10 + 10 + 5) = 0.4; Weight coefficient of carbonate ion concentration: 5 / (10 + 10 + 5) = 0.2.

[0059] 5. The above are the weight coefficients of the influence weights of the pH value, the calcium and magnesium ion concentration, and the carbonate ion concentration on the scaling of production wells in this strong base block. Similarly, the weight coefficients of the influence weights of the pH value, the calcium and magnesium ion concentration, and the carbonate ion concentration on the scaling of production wells in the weak base block can be obtained.

[0060] Weight coefficient of pH value: 0.6; Weight coefficient of calcium and magnesium ion concentration: 0.3; Weight coefficient of carbonate ion concentration: 0.1.

[0061] Step S20: Establish the correlation formulas between the scale formation cause abnormal ratios of the ternary blocks and the pH value, calcium and magnesium ion concentration, and carbonate ion concentration respectively.

[0062] The specific establishment method adopted in the embodiments of the present disclosure is as follows:

[0063] 1. Respectively establish the influence curves of the pH value, calcium and magnesium ion concentration, and carbonate ion concentration on the scale formation cause abnormal ratio, and obtain the relational expressions between the three parameters and the scale formation cause abnormal ratio.

[0064] ① Influence curve of pH value on the proportion of wells with abnormal scale formation causes.

[0065] In the embodiments of the present disclosure, taking the strong alkali block as an example, by single factor analysis of the proportion of wells with abnormal scale formation causes in different intervals within the pH value range shown in Table 1, Table 3 is obtained; then, taking the average value of the interval pH value range as the abscissa and the scale formation cause abnormal ratio as the ordinate, the influence curve of the pH value on the proportion of wells with abnormal scale formation causes is drawn, specifically as Figure 2 shown.

[0066] Table 3 Proportion of wells with abnormal scale formation causes at different pH value ranges

[0067]

[0068] ② Similarly, obtain the influence curves of the calcium and magnesium ion concentration and carbonate ion concentration on the proportion of wells with abnormal scale formation causes, as shown in Figure 3 and Figure 4 shown respectively.

[0069] 2. Respectively fit the Figures 2 - 4 influence curves to obtain the correlation formulas between the proportion of wells with abnormal scale formation causes and the pH value, calcium and magnesium ion concentration, and carbonate ion concentration respectively, as follows:

[0070] a = -0.921x 2 + 18.385x - 86.582 (x is the pH value);

[0071] b = 0.00004y 2 - 0.0451y + 6.0334 (y is the calcium and magnesium ion concentration);

[0072] c = -0.0000006z 2 + 0.0037z + 0.913 (z is the carbonate ion concentration);

[0073] Similarly, the correlation formulas between the proportion of wells with abnormal scale formation causes and the pH value, calcium and magnesium ion concentration, and carbonate ion concentration in the weak alkali block of the ternary block are as follows:

[0074] a = -0.259x 2 +6.4345x - 33.717 (x is the pH value)

[0075] b = -0.0008y 2 +0.0745y + 1.636 (y is the calcium and magnesium ion concentration)

[0076] c = -0.0000001z 2 +0.0011z + 2.9724 (z is the carbonate ion concentration)

[0077] Step S30: Establish a calculation formula for quantitatively describing the scaling degree of a single well in the block production well according to the weight coefficient and the correlation formula.

[0078] The specific establishment method adopted in the embodiments of the present disclosure is: Multiply the sum of the weight coefficients of the pH value, calcium and magnesium ion concentration, and carbonate ion concentration in Step S10 by the corresponding correlation formulas in Step S20, and the correlation formula between the apparent scaling coefficient S of the strong and weak base blocks and the three parameters of the pH value, calcium and magnesium ion concentration, and carbonate ion concentration can be obtained.

[0079] For the strong base block in this ternary block:

[0080] S = 0.4a + 0.4b + 0.2c

[0081] a = -0.921x 2 +18.385x - 86.582 (x is the single well pH value)

[0082] b = 0.00004y 2 -0.0451y + 6.0334 (y is the single well calcium and magnesium ion concentration)

[0083] c = -0.0000006z 2 +0.0037z + 0.913 (z is the single well carbonate ion concentration)

[0084] For the weak base block in this ternary block:

[0085] S = 0.6a + 0.3b + 0.1c

[0086] a = -0.259x 2 +6.4345x - 33.717 (x is the single well pH value)

[0087] b = -0.0008y 2 +0.0745y + 1.636 (y is the single well calcium and magnesium ion concentration)

[0088] c = -0.0000001z 2+0.0011z + 2.9724 (where z is the carbonate ion concentration in a single well)

[0089] In the formula, S is the apparent scaling coefficient, and the scaling degree of each production well in the ternary block is quantitatively described by this apparent scaling coefficient.

[0090] Application example

[0091] The method of the present disclosure is applied to a certain ternary composite flooding block, which is a strong alkali block and includes 86 production wells. The parameter data of the pH value, calcium and magnesium ion concentration, and carbonate ion concentration of each well are shown in Table 4 below. According to the correlation formula of the embodiment of the present disclosure, it can be calculated that the apparent scaling coefficient S of each well under different parameters is different. The smaller the apparent scaling coefficient, the lighter the scaling, and the larger the apparent scaling coefficient, the more serious the scaling.

[0092] Among them, the calculation process of the apparent scaling coefficient of Well No. 1 is as follows:

[0093] Apparent scaling coefficient = 0.6*(-0.259x 2 + 6.4345x - 33.717) + 0.3*(-0.0008y 2 + 0.0745y + 1.636) + 0.1*(-0.0000001z 2 + 0.0011z + 2.9724) = 0.6*(-0.259*11.06 2 + 6.4345*11.06 - 33.717) + 0.3*(-0.0008*0 2 + 0.0745*0 + 1.636) + 0.1*(-0.0000001*3031 2 + 0.0011*3031 + 2.9724) = 5.37

[0094] Table 4 Apparent scaling coefficient of a single well

[0095] Well Number pH Value Carbonate Ion (mg / L) Calcium and Magnesium Ion (mg / L) Apparent Scaling Coefficient 1 11.06 3031 0.00 5.37 2 11.63 2821 0.00 4.79 3 10.42 2821 60.75 4.69 4 10.31 2941 51.38 4.88 5 11.06 3031 0.00 5.37 6 11.63 2821 0.00 4.79 7 10.42 2821 60.75 4.69 8 10.31 2941 51.39 4.88 9 12.08 3181 0.00 4.18 10 9.60 2881 61.11 4.70 11 11.37 3091 0.00 5.09 12 10.77 2821 0.00 5.57 13 12.08 3181 0.00 4.18 14 9.6 2881 61.11 4.70 15 11.37 3091 0.00 5.09 16 10.77 2821 0.00 5.57 17 11.3 3136 0.00 5.16 18 11 3196 0.00 5.42 19 10.5 3061 54.31 4.77 20 10.93 2941 0.00 5.47 21 10.57 2911 49.02 4.83 22 11.3 3136 0.00 5.16 23 11 3196 0.00 5.42 24 10.5 3061 54.31 4.77 25 10.93 2941 0.00 5.47 26 10.57 2911 49.02 4.83 27 10.04 3181.06 40.94 5.09 28 10.85 3091 0.00 5.53 29 10.44 2866 50.17 4.86 30 10.04 3181.06 40.93 5.09 31 10.85 3091 0.00 5.53 32 10.44 2866 50.17 4.86 33 9.84 3151.05 28.98 5.29 34 11.15 2866 0.00 5.30 35 11.35 2851 0.00 5.11 36 11.23 2881 0.00 5.22 37 11.60 2896 0.00 4.83 38 10.14 3061 60.26 4.77 39 10.25 2821 60.32 4.74 40 9.84 3151.05 28.98 5.29 41 11.15 2866 0.00 5.30 42 11.35 2851 0.00 5.11 43 11.23 2881 0.00 5.22 44 11.6 2896 0.00 4.83 45 10.14 3061 60.26 4.77 46 10.25 2821 60.32 4.74 47 9.77 2880.96 37.78 5.12 48 9.74 2940.98 38.50 5.11 49 9.78 3061.02 54.67 4.85 50 9.98 2940.98 0.00 5.80 51 9.94 3091.03 16.89 5.50 52 10.60 2836 0.00 5.66 53 9.77 2880.96 37.79 5.12 54 9.74 2940.98 38.50 5.11 55 9.78 3061.02 54.67 4.85 56 9.98 2940.98 0.00 5.80 57 9.94 3091.03 16.88 5.50 58 10.6 2836 0.00 5.66 59 12.60 3181.06 0.00 3.28 60 9.24 3016.01 47.38 4.78 61 8.85 3001 74.13 4.08 62 12.15 3121 0.00 4.07 63 11.45 3001 0.00 5.01 64 11.44 2866 0.00 5.01 65 11.03 2851 0.00 5.39 66 10.91 2941 0.00 5.48 67 10.80 2926 0.00 5.55 68 10.96 3091 54.24 4.52 69 10.09 3091 0.00 5.80 70 10.4 2853 40.55 5.03 71 9.58 2807 48.23 4.90 72 12.6 3181.06 0.00 3.28 73 9.24 3016.01 47.38 4.78 74 8.85 3001 74.13 4.08 75 12.15 3121 0.00 4.07 76 11.45 3001 0.00 5.01 77 11.44 2866 0.00 5.01 78 11.03 2851 0.00 5.39 79 10.91 2941 0.00 5.48 80 10.8 2926 0.00 5.55 81 10.96 3091 54.24 4.52 82 10.09 3091 0.00 5.80 83 10.4 2853 40.55 5.03 84 9.58 2807 48.23 4.90 85 10.10 3061.02 16.89 5.50 86 8.46 3001.00 53.03 4.04

[0096] Because this apparent scaling coefficient S characterizes the scaling degree of each production well in the ternary block, it can be used to predict whether the well needs to add chemicals, or needs to reduce or stop adding chemicals, so as to provide a technical identification boundary for guiding the pump sticking caused by scaling and non-scaling reasons.

[0097] The above-described embodiments are only illustrative of the implementation manners of the present disclosure. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patents of the present disclosure. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present disclosure, several modifications, equivalent substitutions, improvements, etc. can be made, and these all fall within the protection scope of the present disclosure. Therefore, the protection scope of the patents of the present disclosure shall be subject to the appended claims.

Claims

1. A method for quantitatively describing the scale formation degree of production wells in the ASP flooding, characterized in that, Including: Taking the pH value, calcium and magnesium ion concentrations, and carbonate ion concentration as the characterization parameters for the scaling degree of the production wells in the ternary block, and determining the weight coefficients of each characterization parameter; Establishing the correlation formulas between the abnormal well times ratio of the scaling causes in the ternary block and the pH value, calcium and magnesium ion concentrations, and carbonate ion concentration respectively; Establishing a calculation formula for quantitatively describing the scaling degree of a single production well in the block according to the weight coefficient and the correlation formula; The method for determining the weight coefficient of the pH value includes: Obtaining the pH value range of the scaling wells in the production wells of the ternary block, and dividing the pH value range into a set number of intervals; For the scaling wells, respectively counting the well times with abnormal scaling causes in each of the intervals of the pH value according to the initial scaling stage, the middle scaling stage, and the late scaling stage, and the total well times with abnormal scaling causes corresponding to the initial scaling stage, the middle scaling stage, and the late scaling stage respectively; The ratio of the well times to the corresponding total well times is the abnormal well times ratio of scaling causes in each interval; Calculating the absolute value of the difference in the abnormal well times ratio of scaling causes between adjacent intervals, and taking the average value of the absolute values as the fluctuation value of the abnormal well times ratio of scaling causes; Taking the average value of the fluctuation values of the abnormal well times ratio of scaling causes in the initial scaling stage, the middle scaling stage, and the late scaling stage as the influence weight of the pH value.

2. The method for quantitatively describing the scaling degree of a ternary composite flooding production well according to claim 1, wherein The method for establishing the correlation formula between the abnormal well times ratio of scaling causes and the pH value includes: Counting the abnormal well times ratio of scaling causes occurring in each of the intervals within the pH value range of the ternary block, and plotting a curve of the influence of the pH value on the abnormal well times ratio of scaling causes with the average value of the interval pH values as the abscissa and the corresponding ratio of the abnormal well times of scaling causes as the ordinate to obtain the correlation formula.

3. The method for quantitatively describing the scaling degree of the production wells in the ternary composite flooding according to claim 1, wherein: The sum of each of the correlation formulas multiplied by the corresponding weight coefficient is the calculation formula for quantitatively describing the scaling degree of a single production well in the block.

4. The method for quantitatively describing the scaling degree of the production wells in the ternary composite flooding according to any one of claims 1-3, wherein: The set number of the intervals is 10.

Images