Water injection regulation and control scheme comprehensive evaluation and optimization method based on principal component analysis method

Abstract

A water injection regulation and control scheme comprehensive evaluation and optimization method based on a principal component analysis method comprises the specific steps that S1, according to screening conditions, all water injection schemes meeting the conditions are screened out; s2, according to the screened water injection scheme, parameter indexes on which the principal component analysis score depends are selected; s3, removing unnecessary parameter indexes according to the parameter indexes screened out in the S2; s4, according to the screened parameter indexes, performing comprehensive evaluation on all the water injection schemes meeting the conditions by using a principal component analysis method; and S5, performing comprehensive evaluation on the water injection scheme by using a principal component analysis method to obtain a comprehensive score. According to the comprehensive evaluation and optimization method for the water injection regulation and control scheme based on the principal component analysis method, the feasible water injection regulation and control scheme is analyzed layer by layer, the optimal water injection regulation and control scheme under the principal component analysis method is extracted, and the method has great significance in guiding operation of field technicians.

Description

Technical Field

[0001] The invention relates to the technical field of water injection development of petroleum engineering, and more specifically to a comprehensive evaluation and optimization method for water injection control schemes based on a principal component analysis method. Background Art

[0002] The trend of deteriorating resource quality and high water content in major old oil fields have led my country's oil fields into a new stage of deep and refined development. Refined stratification, water injection and stratified oil production technologies have been gradually applied to major oil fields. The application of this technology can play a key role in dealing with the contradiction between the long-term development goals of oil fields and actual output, thereby achieving more oil production.

[0003] Researchers from multiple oil fields have conducted a large number of water injection control scheme analyses, improving research on aspects such as the refinement of water injection in each layer. However, the research content only stays on specific data comparison and analysis, and no optimization of water injection control schemes is performed from the perspective of comprehensive evaluation. Summary of the invention

[0004] The present invention overcomes the deficiencies in the prior art and provides a comprehensive evaluation and optimization method for water injection control schemes based on a principal component analysis method.

[0005] The purpose of the present invention is achieved through the following technical solutions.

[0006] A comprehensive evaluation and optimization method for water injection control schemes based on principal component analysis method, the specific steps include:

[0007] S1. According to the screening conditions, all water injection schemes that meet the conditions are screened out;

[0008] S2, based on the water injection scheme selected in S1, select the parameter index on which the principal component analysis score depends;

[0009] S3, according to the parameter indicators screened in S2, remove unnecessary parameter indicators;

[0010] S4. Based on the selected parameter indicators, use the principal component analysis method to comprehensively evaluate all qualified water injection schemes and calculate the comprehensive score of each scheme;

[0011] S5. Based on the comprehensive score obtained by comprehensively evaluating the water injection scheme using the principal component analysis method, the water injection control scheme that best meets the on-site plan is selected according to the standard that the smaller the comprehensive score, the better the scheme.

[0012] The screening conditions for water injection schemes in S1 include:

[0013] The upper and lower limits of the allowable error of injection are 0.15*theoretical injection volume;

[0014] The injection pressure at the wellhead is less than the maximum allowable injection pressure of the well;

[0015] The wellhead injection pressure is greater than the minimum wellhead injection pressure.

[0016] The specific steps of S1 include: determining the pressure boundary and the water nozzle opening boundary, traversing the injection volume under different water nozzle openings under different pressures, setting the injection volume as the allowable lower limit of the injection allocation to 0.85*theoretical injection volume, solving the actual injection volume of each layer of the injection plan, judging whether the injection volume of each layer is within the allowable error range, and outputting all plans that meet the injection allocation requirements.

[0017] S2 uses the Spearman correlation analysis method to calculate parameter indicators and retains parameter indicators with correlation coefficients greater than 0.1.

[0018] The index parameters include: injection error of each layer, nozzle loss of each layer, friction loss of each layer, total nozzle loss of each layer, total water injection volume error at the wellhead and injection pressure at the wellhead.

[0019] The parameter indicators used to calculate the comprehensive score in S4 are obtained from S3.

[0020] In S4, the injection pressure and the water injection loss of each layer are normalized, and the contribution of each component after normalization is obtained for participation weight calculation.

[0021] The comprehensive score calculation steps in S4 include:

[0022] A1. Obtain indicator matrix X m×n And the standardized sample matrix X′ m×n ;

[0023] Among them, n is the number of indicators and m is the number of solutions;

[0024] A2. Calculate the correlation coefficient matrix R between the indicator matrix and the standardized sample matrix;

[0025] A3. Calculate the eigenvalues ​​of the correlation coefficient matrix R λ=[λ1,λ2,...,λ n ] and eigenvector matrix B;

[0026] A4. Calculate the contribution δ of the i-th monitoring parameter based on the eigenvector and eigenvalue i , calculate the weight of the main control parameters through the contribution

[0027] A5. Calculate the comprehensive score of any solution F = aX′;

[0028] Among them, X′ is the value of the indicator parameter of the scheme after standardization and feature conversion, and the weight matrix is ​​a.

[0029] The beneficial effects of the present invention are as follows: the present invention provides a comprehensive evaluation and optimization method for water injection control schemes based on the principal component analysis method, and the establishment of the scheme is to analyze the feasible water injection control schemes layer by layer and extract the optimal water injection control scheme under the principal component analysis method. It is of great significance to guide the work of on-site technicians. DETAILED DESCRIPTION

[0030] Example

[0031] This embodiment takes the actual application of water injection well A in water injection regulation operation as an example.

[0032] The water injection well has 3 layers with different formation pressures. The upper and lower limits of the allowable error of the water injection well are 0.15*theoretical injection volume, the upper limit of the wellhead injection pressure is less than the maximum allowable injection pressure at the wellhead, and the lower limit of the wellhead injection pressure is greater than the minimum injection pressure at the wellhead.

[0033] S1. According to the screening conditions, all the water injection schemes that meet the conditions are screened out, and the partial water injection schemes that meet the conditions are counted as follows:

[0034] Table 1 Feasible injection schemes

[0035]

[0036]

[0037] S2. Based on the selected water injection schemes, select the parameter indicators on which the principal component analysis score depends.

[0038] The index parameters include: injection error of each layer, nozzle loss of each layer, friction loss of each layer, total nozzle loss of each layer, total water injection volume error at the wellhead and injection pressure at the wellhead.

[0039] S3. Calculate the parameter indexes using the correlation analysis method, and retain the parameter indexes with a correlation coefficient greater than 0.1. The retained parameter indexes include: injection error of each layer, the total loss of each water nozzle and the wellhead injection pressure.

[0040] S4. Based on the selected parameter indicators, the principal component analysis (PCA) method is used to conduct a comprehensive evaluation of all qualified water injection schemes.

[0041] The selected parameter indicators include: injection error of each layer, the total loss of each water nozzle and the wellhead injection pressure. The principal component analysis (PCA) is used to obtain the comprehensive index of each injection scheme.

[0042] The injection pressure and the water injection loss of each layer are normalized, and the contribution of each component after normalization is obtained.

[0043] After normalization, all feasible injection schemes can be ranked. The ranking results include:

[0044] Table 2 Scoring table for feasible injection schemes

[0045]

[0046]

[0047]

[0048] S5. According to the above steps, it can be concluded that the lower the score, the better the feasibility of the water injection scheme. After considering energy consumption and water injection loss, it can be concluded that the current optimal injection pressure is 5.8MPa, and the optimal water nozzle openings of each layer are 9%, 90% and 9%. At this time, the optimal score is 0.22322.

[0049] The embodiments of the present invention are described in detail above, but the contents described are only preferred embodiments of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A comprehensive evaluation and optimization method for water injection control schemes based on principal component analysis, characterized in that: The specific steps include: S1. Filter out all water injection schemes that meet the conditions according to the screening conditions; S2. Based on the water injection schemes selected in S1, select the parameter indicators on which the principal component analysis scores depend; S3. Remove unnecessary parameter indicators based on the parameter indicators screened in S2; S4. Based on the selected parameter indicators, use the principal component analysis method to comprehensively evaluate all qualified water injection schemes and calculate the comprehensive score of each scheme; S5. Based on the comprehensive score obtained by comprehensively evaluating the water injection scheme using the principal component analysis method, the water injection control scheme that best meets the on-site plan is selected according to the standard that the smaller the comprehensive score, the better the scheme.

2. The method for comprehensive evaluation and optimization of water injection control schemes based on principal component analysis according to claim 1, characterized in that: The screening conditions for water injection schemes in S1 include: The upper and lower limits of the allowable error for injection are 0.15*theoretical injection volume; The wellhead injection pressure is less than the maximum allowable injection pressure of the well; The wellhead injection pressure is greater than the minimum wellhead injection pressure.

3. The method for comprehensive evaluation and optimization of water injection control schemes based on principal component analysis according to claim 2, characterized in that: The specific steps of S1 include: determining the pressure boundary and the water nozzle opening boundary, traversing the injection volume under different water nozzle openings at different pressures, setting the injection volume as the lower limit of the allowable injection volume to 0.85*theoretical injection volume, solving the actual injection volume of each layer of the water injection plan, judging whether the injection volume of each layer is within the allowable error range, and outputting all plans that meet the injection requirements.

4. The method for comprehensive evaluation and optimization of water injection control schemes based on principal component analysis according to claim 1, characterized in that: S3 uses the Spearman correlation analysis method to calculate parameter indicators and retains parameter indicators with correlation coefficients greater than 0.

1.

5. The method for comprehensive evaluation and optimization of water injection control schemes based on principal component analysis according to claim 1, characterized in that: The index parameters include: injection error of each layer, nozzle loss of each layer, friction loss of each layer, total nozzle loss of each layer, total water injection volume error at the wellhead and wellhead injection pressure.

6. The method for comprehensive evaluation and optimization of water injection control schemes based on principal component analysis according to claim 1, characterized in that: The parameter indicators used to calculate the comprehensive score in S4 are obtained from S3.

7. The method for comprehensive evaluation and optimization of water injection control schemes based on principal component analysis according to claim 1, characterized in that: In S4, the injection pressure and the water injection loss of each layer are normalized to obtain the contribution of each component after normalization for participation weight calculation.

8. The method for comprehensive evaluation and optimization of water injection control schemes based on principal component analysis according to claim 1, characterized in that: The steps for calculating the comprehensive score in S4 include: A1. Obtain indicator matrix X m×n And the standardized sample matrix X′ m×n ; Among them, n is the number of indicators and m is the number of solutions; A2. Calculate the correlation coefficient matrix R between the indicator matrix and the standardized sample matrix; A3. Calculate the eigenvalues ​​of the correlation coefficient matrix R λ=[λ1,λ2,...,λ n ] and eigenvector matrix B; A4. Calculate the contribution δ of the i-th monitoring parameter based on the eigenvector and eigenvalue i , calculate the weight of the main control parameters through contribution A5. Calculate the comprehensive score of any solution F = aX′; Among them, X′ is the value of the indicator parameter of the scheme after standardization and feature conversion, and the weight matrix is ​​a.

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