Method and system for quantitatively evaluating recovery potential of long-stop well

Abstract

The invention belongs to the technical field of oil reservoir development, and discloses a method and system for quantitatively evaluating the recovery potential of a long-stop well, and the method comprises the steps: screening characterization parameters of recovery potential indexes of the long-stop well in a reservoir, and obtaining main control characterization parameters; according to the master control characterization parameters, determining corresponding dimensionless characterization parameters; according to the block development condition of the reservoir, the influence proportion of the master control characterization parameters on the long-stop well recovery potential is determined; according to the dimensionless characterization parameters and the influence proportion, the recovery potential index of the long-stop well is determined; and according to the recovery potential index of the long-stop well, the recovery potential is determined. The oil-water well recovery potential index evaluation method is innovatively established by systematically and comprehensively considering recovery potential related factors, starting from factors affecting recovery potential, introducing recovery potential indexes and utilizing mathematical methods such as fuzzy calculation, the recovery potential indexes are qualitative, specific index parameters can be quantified, and the recovery success rate of a long-stop well is increased from 60% to 80%. Good economic benefits are obtained, and the well opening rate of an oil well is improved.

Description

Technical Field

[0001] The invention relates to the technical field of oil reservoir development, and in particular to a method for identifying the production resumption potential of a long-shut-down well, and in particular to a method and system for quantitatively evaluating the production resumption potential of a long-shut-down well. Background Art

[0002] After the oilfield enters the stage of extremely high water cut, a certain number of oil and water wells are shut down for a long time due to casing damage, flooding, low pressure and low production, which directly affects the production and economic benefits of the oilfield. In order to evaluate the potential for resumption of production of long-stopped wells, there is no systematic research at home and abroad. Some domestic oilfields have only done some related potential tapping and management work, and have not conducted in-depth research on the management boundaries, considering fewer parameters. As a result, it is difficult to further improve the accuracy of the potential for resumption of production of long-stopped wells. Summary of the invention

[0003] In order to overcome the shortcomings of the prior art, the present invention solves the problem that the potential for resumption of production of long-shut wells is descriptive, qualitative, and heavily dependent on the work experience of the evaluator. Starting from the factors affecting the resumption of production of long-shut wells, the logical analysis method is used to optimize the evaluation parameters for the potential for resumption of production: remaining oil potential, reservoir conditions, injection-production relationship, liquid production capacity, production and water content of surrounding adjacent wells. The weights of various parameters are determined by the hierarchical analysis method and fuzzy mathematics method. The resumption potential index is obtained after normalization, the resumption potential of long-shut wells is quantified, and the resumption of production of long-shut wells is recommended in combination with economic evaluation, thereby improving the success rate of the resumption of production wells.

[0004] The above purpose is achieved through the following technical solutions:

[0005] A method for quantitatively evaluating the production resumption potential of a long-shut-down well comprises the following steps:

[0006] S1: Screening the characterization parameters of the long-stop well recovery potential index in the reservoir to obtain the main control characterization parameters;

[0007] S2: Determine the corresponding dimensionless characterization parameter according to the main control characterization parameter;

[0008] S3: According to the block development of the reservoir, determine the influence ratio of the main control characterization parameters on the potential for resumption of production of long-stopped wells;

[0009] S4: Determine the potential index of long-shutdown wells to resume production based on dimensionless characterization parameters and impact ratios;

[0010] S5: Determine the potential for resumption of production based on the long-shutdown well resumption potential index.

[0011] Furthermore, there are multiple master control characterization parameters.

[0012] Further, the master control characterization parameters include static master control characterization parameters and dynamic master control characterization parameters;

[0013] Furthermore, the step of screening the characterization parameters that affect the recovery potential index in the reservoir to obtain the main control characterization parameters includes: screening multiple static characterization parameters according to the causal relationship, equivalence relationship and definition relationship between the multiple static characterization parameters and the process relationship of the multiple static characterization parameters in the geological modeling process to obtain the static main control characterization parameters;

[0014] According to the causal relationship, equivalent relationship and definition relationship among multiple dynamic characterization parameters and the process relationship of multiple dynamic characterization parameters in the geological modeling process, multiple dynamic characterization parameters are screened to obtain dynamic main control characterization parameters.

[0015] In a feasible implementation manner, the step of determining the corresponding dimensionless characterization parameter according to the master control characterization parameter includes:

[0016] Obtain the main control characterization parameter value corresponding to each single well;

[0017] Determine an average value among the main control characterization parameter values, and determine the ratio of each main control characterization parameter value to the average value as a dimensionless characterization parameter value;

[0018] The dimensionless calculation formula is as follows

[0019]

[0020] In a feasible implementation manner, according to the block development situation of the reservoir, the step of determining the influence ratio of the main control characterization parameter on the long-stop well recovery potential index of the reservoir includes:

[0021] According to the development situation of the block, the importance of multiple main control characterization parameters on the potential index of long-stopped wells is analyzed;

[0022] According to the degree of influence, multiple main control characterization parameters are compared in pairs to determine the influence importance judgment results between the multiple main control characterization parameters;

[0023] According to the results of the impact importance judgment, the influence ratio of the main control characterization parameters on the production resumption potential index of the long-shutdown wells is determined.

[0024] The standards are as follows:

[0025] If the influence of the characterization parameter (ω1) and the characterization parameter (ω2) is of equal importance, then ω1 / ω2 = 1:1;

[0026] If the characterization parameter (ω1) is slightly more important than the characterization parameter (ω2), then ω1 / ω2=3:1;

[0027] If the characterization parameter (ω1) is significantly more important than the characterization parameter (ω2), then ω1 / ω2 = 5:1;

[0028] If the characterization parameter (ω1) is more important than the characterization parameter (ω2), then ω1 / ω2=7:1;

[0029] If the characterization parameter (ω1) is more important than the characterization parameter (ω2), then ω1 / ω2=9:1;

[0030] If the influence of the characterization parameter (ω1) and the characterization parameter (ω2) is adjacent, the middle value can be taken.

[0031] In a feasible implementation manner, the step of determining the long-shutdown well resumption potential index according to the dimensionless characterization parameter and the influence ratio includes:

[0032] According to the impact ratio, a discriminant matrix is ​​established;

[0033] According to the discriminant matrix, determine the influence weight value of each main control characterization parameter;

[0034] The calculation process is as follows:

[0035] ① Establish a discriminant matrix (taking n main control characterization parameters as an example)

[0036]

[0037] ②Calculate the weight value of the characterization parameter

[0038]

[0039] The product of the dimensionless characterization parameter corresponding to each main control characterization parameter and the influence weight value is calculated, and the sum of multiple products is determined as the production recovery potential index.

[0040] In a feasible implementation, the step of determining the production resumption potential index according to the production resumption potential of a long-shutdown well includes:

[0041] According to the production resumption potential index, determine the production resumption potential index of each shut-in well;

[0042] The calculation formula is as follows:

[0043] Q L =W1Q1+W 21 Q 21 +W 22 Q 22 +W3Q3+W4Q4+W5Q5+W6Q6

[0044] Where: Q L —Resumption potential index;

[0045] Q1, Q21 , Q 22 , Q3, Q4, Q5, Q6—are the evaluation indicators respectively;

[0046] W1, W 21 , W 22 , W3, W4, W5, W6—are the comprehensive weights of each evaluation index.

[0047] In some feasible examples, static characterization parameters include, but are not limited to, sedimentary facies, reservoir heterogeneity, permeability, porosity, pore radius, oil saturation, underground crude oil viscosity, sand body thickness, remaining reserves and other parameters;

[0048] Dynamic characterization parameters include, but are not limited to, oil production, water production, liquid production, water content, injection-production intensity, water drive control degree and other parameters.

[0049] The preferred quantifiable specific indicator parameters include dimensionless remaining geological reserves, dimensionless total effective thickness and dimensionless single-layer effective thickness, dimensionless water drive control degree, dimensionless specific liquid production index, dimensionless production, dimensionless water content and other factors.

[0050] It is divided into Class A, Class B and Class C. Class A represents great development potential; Class B represents large potential for resumption of production; and Class C represents small potential for development.

[0051] A system for quantitatively evaluating the potential for resumption of production of a long-shut-down well, comprising:

[0052] The first construction unit is to screen the characterization parameters of the long-stop well recovery potential index in the reservoir to obtain the main control characterization parameters;

[0053] A second construction unit determines corresponding dimensionless characterization parameters according to the main control characterization parameters;

[0054] The third construction unit determines the influence ratio of the main control characterization parameters on the production resumption potential of the long-stopped wells according to the block development situation of the reservoir;

[0055] The fourth construction unit determines the production resumption potential index of the long-shutdown well according to the dimensionless characterization parameter and the influence ratio;

[0056] The fifth construction unit determines the potential for resumption of production based on the potential index for resumption of production of long-shut wells.

[0057] A computer-readable storage medium stores at least one program code, and the at least one program code is loaded and executed by a processor to implement the method for quantitatively evaluating the potential for resumption of production of a long-shutdown well as described above.

[0058] An electronic device includes one or more processors and one or more memories, wherein the one or more memories store at least one program code, and the at least one program code is loaded and executed by the one or more processors to implement the above-mentioned method for quantitatively evaluating the potential for resumption of production of long-shutdown wells.

[0059] The beneficial effects of the present invention compared with the prior art are:

[0060] Systematically and comprehensively consider the factors related to the potential for resumption of production, start with the factors affecting the potential for resumption of production, introduce the potential for resumption of production index, use mathematical methods such as fuzzy calculation, and innovatively establish the evaluation method for the potential for resumption of production index of oil and water wells, so as to achieve the qualitative nature of the potential for resumption of production index, and quantify specific index parameters, including dimensionless remaining geological reserves, dimensionless total effective thickness and dimensionless single-layer effective thickness, dimensionless water drive control degree, dimensionless specific production index, dimensionless production, dimensionless water content and other factors, so as to improve the success rate of wells that resume production. The success rate of long-stopped wells resuming production has increased from 60% to 80%, achieving good economic benefits and increasing the rate of oil well opening. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0062] Figure 1 is a flow chart of the method of the present invention;

[0063] Figure 2 is a system schematic diagram of the present invention;

[0064] Figure 3 It is the recovery potential index diagram of the present invention. DETAILED DESCRIPTION

[0065] In order to describe the features of the present invention in more detail and accurately, the following reference embodiments are given for detailed description with reference to the relevant drawings, which are intended to be used to explain the present invention but cannot be interpreted as limiting the present invention.

[0066] Example 1

[0067] A method for evaluating the potential index of long-stop well resumption of production is shown in the attached Figure 1 ,include:

[0068] Step 101, the static characterization parameters and dynamic characterization parameters that affect the target reservoir recovery potential distribution are screened, and according to the screening principle, the main control characterization parameters that affect the target recovery potential are screened and obtained, wherein the main control characterization parameters include: remaining oil potential, reservoir conditions, injection-production relationship, liquid production capacity, adjacent well production, and adjacent well water content;

[0069] Determine the screening principles for each parameter, including that the selected parameters must have strong independence, exclude parameters with causal relationships, definition relationships, equivalence relationships, and process relationships, and the selected parameters must be able to accurately describe the potential for resumption of production and be indicators that can be obtained in large quantities in production.

[0070] Step 102, dimensionlessizing the selected master control characterization parameters;

[0071] Since there are differences in calculation units, orders of magnitude and other factors among the main control parameters, they need to be dimensionless before unified evaluation to eliminate the influence of calculation units and orders of magnitude so that the main control parameters can be compared on a horizontal line.

[0072] (1) Remaining oil potential index

[0073] The dimensionless remaining geological reserves Q1 of the oil well are used to characterize the remaining oil potential. The dimensionless remaining geological reserves refer to the remaining geological reserves R of the shut-in oil wells being evaluated. MBYJ The average remaining geological reserves R of a single well in the block where the shut-in oil well is located QK The following indicators are dimensionless using this method.

[0074] Q1=R MBYJ / R QK

[0075] R MBYJ — Remaining geological reserves of the target well, 10 4 t;

[0076] R QK —The average remaining geological reserves of a single well in the block where the target oil well is located, 10 4 t.

[0077] (2) Reservoir condition potential indicators

[0078] The dimensionless total effective thickness Q of oil-bearing sandstone is used 21 and the dimensionless average effective thickness of a single oil-bearing sandstone layer Q 22 To characterize the reservoir conditions of the target oil well being evaluated at that time.

[0079] Q 21 =H MBYJ / H QK

[0080] Q 22 =h MBYJ / h QK

[0081] H MBYJK —Total effective thickness of oil-bearing sandstone in the target well, m;

[0082] H QK —Total effective thickness of oil-bearing sandstone in the block where the target well is located, m;

[0083] h MBYJ —Average single-layer effective thickness of the target well, m;

[0084] h QK —The average single-layer effective thickness of the block where the target well is located, m.

[0085] (3) Potential indicators of injection and production conditions

[0086] The dimensionless water drive control degree Q3 is used to characterize the connectivity between the target oil well being evaluated and the connected water well, which characterizes the degree of injection-production perfection.

[0087] Q3=E MBYJ / E QK

[0088] E MBYJ —Water drive control degree of the target well, %;

[0089] E QK —Water drive control degree in the block where the target well is located, %.

[0090] (4) Liquid production capacity potential index

[0091] The dimensionless liquid production index Q4 is used to characterize the liquid production capacity of the target oil well being evaluated at that time, thereby reflecting the physical properties of the oil layer of the target oil well being evaluated.

[0092] Q4=J MBYJ / J QK

[0093] J MBYJ —Specific production fluid index of the target well;

[0094] J QK —The average specific liquid production index of the block where the target well is located.

[0095] (5) Production index of adjacent wells

[0096] The dimensionless production index Q5 is used to characterize the production capacity of the target oil well being evaluated at that time, thereby reflecting the production capacity of the oil layer of the target oil well being evaluated.

[0097] Q5=BMBYJ / B QK

[0098] B MBYJ —The average production of the target well’s neighboring wells;

[0099] B QK —The average production of the block where the target well is located.

[0100] (6) Water content index of adjacent wells

[0101] The dimensionless water content index Q6 is used to characterize the water content of the neighboring wells of the target oil well being evaluated, thereby reflecting the water content of the oil layer of the target oil well being evaluated.

[0102] Q6=C QK / C MBYJ

[0103] C MBYJ —Water content of the neighboring wells of the target well;

[0104] C QK —The comprehensive water content of the block where the target well is located.

[0105] Step 103, establishing a hierarchical structure of multiple main control characterization parameters, converting the selected main control characterization parameters into impact ratios according to their importance on the production recovery potential, and digitizing the relationship between different main control characterization parameters;

[0106] The continued development potential index indicates the potential for continued development of an oil well. For shut-in oil wells, the value range is generally between 0 and 1. The weights of the main control parameters are shown in Appendix 1. The larger the value, the greater the impact on the continued development potential of the shut-in oil well being evaluated.

[0107] Combining the static geological data of the oil field and the development geological changes of the oil layer, taking into account the historical production status of the oil wells, a comprehensive prediction and evaluation of the shut-in wells is carried out through the established continued development potential evaluation model, and the potential is further optimized through the prediction of its remaining geological reserves according to the development potential classification standards.

[0108] Schedule 1

[0109]

[0110] Step 104, calculating the recovery potential index of each grid of the target reservoir, and obtaining the recovery potential index value of each single well in the target reservoir;

[0111] Calculation formula:

[0112] Q L =0.4*Q1+0.1*Q 21 +0.1*Q 22+0.1*Q3+0.1*Q4+0.1*Q5+0.1*Q6

[0113] Where: Q L —Resumption potential index;

[0114] Q1, Q 21 , Q 22 , Q3, Q4, Q5, Q6—are the evaluation indicators respectively;

[0115] Step 105, interpolating the recovery potential of each grid of the target reservoir to draw a recovery potential distribution map of the entire area;

[0116] According to the distribution of resumption potential contour lines and combined with the injection-production well network, the resumption potential is quantitatively classified into Class A, Class B and Class C. Class A represents great development potential; Class B represents large resumption potential; and Class C represents small development potential.

[0117] Specifically, according to the development stage and development status analysis of the target block, if the recovery potential is greater than 0.8, it is classified as Class A with great development potential. If the recovery potential is 0.5-0.8, it is classified as Class B with relatively large recovery potential. If the recovery potential is less than 0.5, it is classified as Class C with relatively small development potential. Provided here is an example of the comparison of the main control parameters of an old water-driven sandstone oil reservoir in the ultra-high water-cut period.

[0118] The recovery potential index of each well was calculated according to the above method, and some wells with recovery potential are shown in Table 2.

[0119] Schedule 2

[0120]

[0121]

[0122] According to the above process, good results were achieved after resuming production of 4442. After resumption, the daily oil production increased from 0.8t / d before shutdown to 7.6t / d, and the predicted resumption potential index was 0.81, which was equivalent to the actual effect. The dimensionless remaining oil reserves were calculated to be 0.9, the dimensionless effective thickness was 0.6, the dimensionless single layer effective thickness was 0.9, the dimensionless water drive control degree was 0.7, the dimensionless liquid production index was 0.7, the dimensionless production was 0.7, and the dimensionless water content was 0.9. As of February 2023, 6 wells have been implemented, and the success rate has increased from 60% in the past to 80%.

[0123] Recovery potential index Figure 3As shown, by expanding the determined recovery potential index QL according to the grid, the recovery potential index values ​​QL1, QL2, ..., QLn corresponding to each grid can be determined; thus, according to the recovery potential index values ​​QL1 to QLn, through interpolation processing, the recovery potential index distribution map of the reservoir is drawn, so as to convert the relatively discrete recovery potential index values ​​into a map that can reflect the distribution of the recovery potential index QL, and improve the intuitiveness of the description of the recovery potential; then, according to the recovery potential index distribution map, the recovery potential is identified. The recovery potential index distribution map is a contour map of the recovery potential index QL, so that the distribution of the recovery potential index L can be described by contour lines, and the information described by the recovery potential index distribution map is more intuitive and convenient for analysis.

[0124] like Figure 2 As shown, those skilled in the art should understand that the various modules in the above-mentioned invention content: the first building unit, the second building unit, the third building unit, the fourth building unit, and the fifth building unit can be implemented by a general-purpose computing device, they can be concentrated on a single computing device, or distributed on a network composed of multiple computing devices, optionally, they can be implemented by a program code executable by a computing device, so that they are stored in a storage device and executed by the computing device, and in some cases, the steps shown or described can be executed in a different order from that here, or they can be made into individual integrated circuit modules respectively, or multiple modules or steps therein can be made into a single integrated circuit module for implementation. In this way, the embodiments of the present invention are not limited to any specific combination of hardware and software.

[0125] The above-described embodiments are only preferred embodiments of the present invention, but not all feasible embodiments of the present invention. For those skilled in the art, any obvious changes made thereto without departing from the principles and spirit of the present invention should be considered to be included in the scope of protection of the claims of the present invention.

Claims

1. A method for quantitatively evaluating the production resumption potential of a long-shut-down well, characterized in that: The following steps are involved: S1: Screening the characterization parameters of the long-stop well recovery potential index in the reservoir to obtain the main control characterization parameters; S2: Determine the corresponding dimensionless characterization parameter according to the main control characterization parameter; S3: According to the block development of the reservoir, determine the influence ratio of the main control characterization parameters on the potential for resumption of production of long-stopped wells; S4: Determine the potential index of long-shutdown wells to resume production based on dimensionless characterization parameters and impact ratios; S5: Determine the potential for resumption of production based on the long-shutdown well resumption potential index.

2. The method for quantitatively evaluating the production resumption potential of a long-shut-down well as claimed in claim 1, characterized in that: The master control characterization parameters include static master control characterization parameters and dynamic master control characterization parameters.

3. The method for quantitatively evaluating the production resumption potential of a long-shut-down well as claimed in claim 1, characterized in that: Step S1 includes: screening multiple static characterization parameters according to the causal relationship, equivalence relationship and definition relationship among the multiple static characterization parameters and the process relationship of the multiple static characterization parameters in the geological modeling process to obtain the static master control characterization parameters; According to the causal relationship, equivalent relationship and definition relationship among multiple dynamic characterization parameters and the process relationship of multiple dynamic characterization parameters in the geological modeling process, multiple dynamic characterization parameters are screened to obtain dynamic main control characterization parameters.

4. The method for quantitatively evaluating the production resumption potential of a long-shut-down well as claimed in claim 1, characterized in that: Step S2 includes: Obtain the main control characterization parameter value corresponding to each single well; Determine an average value among the main control characterization parameter values, and determine the ratio of each main control characterization parameter value to the average value as a dimensionless characterization parameter value; The dimensionless calculation formula is as follows 5. The method for quantitatively evaluating the production resumption potential of a long-shut-down well as claimed in claim 1, characterized in that: Step S3 includes: According to the development situation of the block, the importance of multiple main control characterization parameters on the potential index of long-stopped wells is analyzed; According to the degree of influence, multiple main control characterization parameters are compared in pairs to determine the influence importance judgment results between the multiple main control characterization parameters; According to the results of the impact importance judgment, determine the impact ratio of the main control characterization parameters on the long-shutdown well resumption potential index; The standards are as follows: If the influence of the characterization parameter (ω1) and the characterization parameter (ω2) is of equal importance, then ω1 / ω2 = 1:1; If the characterization parameter (ω1) is slightly more important than the characterization parameter (ω2), then ω1 / ω2=3:1; If the characterization parameter (ω1) is significantly more important than the characterization parameter (ω2), then ω1 / ω2 = 5:1; If the characterization parameter (ω1) is more important than the characterization parameter (ω2), then ω1 / ω2=7:1; If the characterization parameter (ω1) is more important than the characterization parameter (ω2), then ω1 / ω2=9:1; If the influence of the characterization parameter (ω1) and the characterization parameter (ω2) is adjacent, the middle value can be taken.

6. The method for quantitatively evaluating the production resumption potential of a long-shut-down well as claimed in claim 1, characterized in that: Step S4 includes: According to the impact ratio, a discriminant matrix is ​​established; According to the discriminant matrix, determine the influence weight value of each main control characterization parameter; The calculation process is as follows: ① Establish a discriminant matrix (taking n main control characterization parameters as an example) ②Calculate the weight value of the characterization parameter The product of the dimensionless characterization parameter corresponding to each main control characterization parameter and the influence weight value is calculated, and the sum of multiple products is determined as the production recovery potential index.

7. The method for quantitatively evaluating the production resumption potential of a long-shut-down well as claimed in claim 1, characterized in that: The calculation formula of step S5 is as follows: Q L =W1Q1+W 21 Q 21 +W 22 Q 22 +W3Q3+W4Q4+W5Q5+W6Q6 Where: Q L —Resumption potential index; Q1, Q 21 , Q 22 , Q3, Q4, Q5, Q6—are the evaluation indicators respectively; W1, W 21 , W 22 , W3, W4, W5, W6—are the comprehensive weights of each evaluation index; It is divided into Class A, Class B and Class C. Class A represents great development potential; Class B represents large potential for resumption of production; and Class C represents small potential for development.

8. A system for quantitatively evaluating the potential for resumption of production of a long-shut-down well, characterized in that: include: The first construction unit is to screen the characterization parameters of the long-stop well recovery potential index in the reservoir to obtain the main control characterization parameters; A second construction unit determines corresponding dimensionless characterization parameters according to the main control characterization parameters; The third construction unit determines the influence ratio of the main control characterization parameters on the production resumption potential of the long-stopped wells according to the block development situation of the reservoir; The fourth construction unit determines the production resumption potential index of the long-shutdown well according to the dimensionless characterization parameter and the influence ratio; The fifth construction unit determines the potential for resumption of production based on the potential index for resumption of production of long-shut wells.

9. A computer-readable storage medium, characterized in that: At least one program code is stored in the computer-readable storage medium, and the at least one program code is loaded and executed by the processor to implement the method for quantitatively evaluating the production resumption potential of a long-shutdown well as described in any one of claims 1 to 7.

10. An electronic device, characterized in that: The method comprises one or more processors and one or more memories, wherein at least one program code is stored in the one or more memories, and the at least one program code is loaded and executed by the one or more processors to implement the method for quantitatively evaluating the potential for resumption of production of a long-shutdown well as described in any one of claims 1 to 7.

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