Universal technical effect evaluation method for improving recovery efficiency of oil field

Abstract

The invention provides a universal technical effect evaluation method for improving the recovery efficiency of an oil field. The evaluation method comprises the following steps: calculating an evaluation index of a recovery efficiency improving project; determining the weight of the evaluation index; performing single-project comprehensive evaluation according to the evaluation indexes and the evaluation index weights; and collecting based on the single-project comprehensive evaluation to obtain a technology average comprehensive effect. Different types of technologies are evaluated on the same platform, the problem of comparability of the different types of technologies is solved, the effect of the recovery efficiency improving technology of different types of oil reservoirs is objectively given, and technical support is provided for selection of the recovery efficiency improving technology of an oil field.

Description

Technical Field

[0001] The invention relates to the technical field of oilfield development, and in particular to a universal oilfield enhanced recovery technology effect evaluation method. Background Art

[0002] After years of development, Shengli Oilfield has continuously innovated and developed technologies based on the characteristics of different types of oil reservoirs, and has formed technologies to improve the recovery rate of different types of oil reservoirs. The recovery rate of different types of oil reservoirs has continued to increase, which has played a huge role in slowing down the decline in production of old oil fields and supporting the continued stable production of old oil fields.

[0003] In the process of technology application, different recovery technologies have different input-output effects due to different technical characteristics. Under the condition of limited capital investment, according to the development and economic effects such as technology oil increase, investment, cost, and benefit, it is of great significance to clarify the direction of technology investment and select the best recovery technology to reduce oilfield costs and improve quality and efficiency. However, the current evaluation of recovery technology mainly focuses on the feasibility evaluation before implementation, and there is less evaluation after implementation, and there is no consistent conclusion on the difference in technical effects. On the other hand, due to the diversity of recovery technology, the technical implementation methods, investment, cost and effect are very different, and the current evaluation methods are mainly for the evaluation of specific technologies, which are no longer applicable to other recovery technologies. For example, the relevant industry standards such as "Evaluation Method of Heavy Oil Steam Drive Oil Increase Effect", "Evaluation Method of Tertiary Oil Recovery Oil Increase Effect", and "Evaluation Method of Gas Drive Oil Increase Effect" that have been formed are all for a specific technology, and are not applicable to other types of technologies. The lack of an effect evaluation method that is generally applicable to all types of oilfield recovery technology makes it impossible to put different technologies together for unified evaluation, which has caused great difficulties in the development decision-making of the next step of oilfield recovery technology. Summary of the invention

[0004] In view of the above problems, the present invention is proposed to provide a universal oilfield enhanced oil recovery technology effect evaluation method that overcomes the above problems or at least partially solves the above problems.

[0005] According to one aspect of the present invention, a general method for evaluating the effect of oilfield enhanced oil recovery technology is provided, the evaluation method comprising:

[0006] Calculate evaluation indicators for enhanced oil recovery projects;

[0007] Determining the weight of the evaluation index;

[0008] Performing a comprehensive evaluation of a single project according to the evaluation indicators and the evaluation indicator weights;

[0009] The comprehensive evaluation of the single projects is used as the basis for aggregation to obtain the average comprehensive effect of the technology.

[0010] Optionally, the evaluation index for calculating the enhanced oil recovery project specifically includes: converted enhanced oil recovery, converted enhanced oil recovery rate, increased SEC reserves per million investment and incremental ton oil cost.

[0011] Optionally, the calculation step of converting the enhanced oil recovery factor specifically includes:

[0012] It is defined as the ratio of the cumulative oil production during the project evaluation period to the geological reserves covered by the project, which represents the contribution of technology to long-term production supply;

[0013]

[0014]

[0015] In the formula, E z To convert the enhanced oil recovery factor, %; Q n is the cumulative oil increase, 10 4 t;N z To calculate the geological reserves, 10 4 t;q yi For projects with annual oil production, 10 4 t;q wi There is no project with annual oil production, 10 4 t;

[0016] Among them, the conversion of geological reserves is a variable defined to solve the problem that different technical inputs, scales and workloads are different, and the simple evaluation of the final effect is not comparable;

[0017] According to the input-output characteristics of the technology, there are three cases for calculating the converted geological reserves:

[0018] New well-based technology:

[0019]

[0020] Measures-based technology:

[0021]

[0022] Technologies focusing on long-term investment:

[0023]

[0024] Among them, N z To calculate the geological reserves, 10 4 t; N is geological reserves, 10 4 t;n o is the number of crude oil wells; n w is the number of raw water wells; n n is the number of newly drilled oil and water wells; nc is the number of measures; n z is the number of wells injected with polymer; n s It is the number of effective oil wells after polymer injection.

[0025] Optionally, the calculation step of converting the increased oil recovery rate specifically includes:

[0026] It is defined as the ratio of the average annual oil production increase during the peak period of the project to the converted geological reserves, which represents the contribution of technology to short-term production supply.

[0027] Different types of technologies have different effectiveness characteristics and validity periods. Some technologies take effect quickly, while others have a lag period. The annual average oil increase value norms for the peak period of effectiveness are determined respectively;

[0028] The technology mainly based on new wells is the oil production in the second year after the implementation of the new wells; the technology mainly based on measures is the oil production increase in the year after the measures are implemented; the technology mainly based on continuous investment is the average annual oil production increase from the peak of effectiveness to the year when investment is stopped;

[0029]

[0030] In the formula, v z To convert the increase in oil production rate, %; q nz is the average annual increase in oil production during the peak period, 10 4 t.

[0031] Optionally, the method for calculating the increase in SEC reserves by one million investment specifically includes:

[0032] It is defined as the ratio of the project's increased SEC reserves to the one-time investment of one million yuan, which represents the contribution of one-time technology investment to the increase in SEC reserves;

[0033] There are three types of EOR technologies: new well drilling, production increase measures, and continuous investment. The initial one-time investment varies greatly. This indicator is defined to evaluate the effect of the technology from the perspective of the contribution of the one-time investment.

[0034]

[0035] Where N sm Increase SEC reserves for 1 million investment, 10 4 t / 10 6 Yuan, N s Increase SEC reserves for the evaluation period, 10 4 t; P is the one-time investment, including drilling investment, operating costs, and pharmaceutical costs, 10 6 Yuan.

[0036] Optionally, the incremental oil cost per ton specifically includes:

[0037] It is defined as the ratio of the additional cost of the enhanced oil recovery technology to the cumulative oil, which represents the cost of the additional production of the project;

[0038]

[0039] Among them, C d is the incremental oil cost per ton, RMB / t; C pz The additional cost for the evaluation period; q p is the oil production increase during the evaluation period; I is the investment; C zt is the additional cost in year t; q is the additional oil volume in year t; n is the year of the evaluation period; i is the discount rate;

[0040] The projects are classified according to the enhanced oil recovery technologies they apply, and the relevant parameters are substituted into the indicator calculation formulas of different types of technologies to obtain the project evaluation indicator results.

[0041] Optionally, determining the evaluation index weight specifically includes:

[0042] The CRITIC objective weighting method is selected to calculate the indicator weights. The objective weights of the indicators are comprehensively measured based on the comparative strength of the evaluation indicators and the conflicts between the indicators. The variability of the indicators is considered while taking into account the correlation between the indicators.

[0043] The CRITIC objective weighting method requires dimensionless processing of each indicator. The variability of the indicator is expressed in the form of standard deviation, the conflict of the indicator is expressed by the correlation coefficient, and the information content C is expressed in the form of standard deviation. j The larger it is, the greater the role of the jth evaluation index in the entire evaluation index system, and the more weight is assigned;

[0044]

[0045] In the formula, C j is the information content of the jth evaluation index; S j is the standard deviation of the jth index; P is the number of evaluation indicators; r ij is the correlation coefficient between the i-th evaluation index and the j-th evaluation index;

[0046] So the objective weight W of the jth indicator j for:

[0047]

[0048] Among them, W j is the objective weight of the jth indicator;

[0049] The TOPSIS method was used to calculate the comprehensive evaluation scores of four indicators, namely, single project converted improved recovery factor, converted improved oil production rate, increased SEC reserves per million investment, and incremental ton of oil cost.

[0050] Optionally, the comprehensive evaluation of a single project according to the evaluation index and the evaluation index weight specifically includes:

[0051] The TOPSIS method first normalizes the original matrix and then standardizes it;

[0052] Define the distance between the i-th evaluation object and the maximum value:

[0053]

[0054] In the formula, is the distance between the ith evaluation object and the maximum value; m is the number of evaluation indicators; is the maximum value of the jth evaluation index; z ij is the value of the jth evaluation index of the i-th evaluation object;

[0055] Define the distance between the i-th evaluation object and the minimum value:

[0056]

[0057] In the formula, is the distance between the i-th evaluation object and the minimum value; is the minimum value of the jth evaluation index;

[0058] Calculate the degree of closeness between the i-th evaluation object and the optimal solution:

[0059]

[0060] In the formula, S i is the score of the i-th evaluation object;

[0061] S i The value is between 0 and 1, and the closer it is to 1, the closer the evaluation object is to the optimal level;

[0062] Optionally, the comprehensive evaluation of a single project based on the evaluation indicators and the evaluation indicator weights also includes: using the TOPSIS method to calculate a comprehensive evaluation score for indicators such as the converted improved oil recovery factor, the converted improved oil production rate, the increased SEC reserves per million investment, and the incremental ton of oil cost of the single project.

[0063] Optionally, the aggregation based on the comprehensive evaluation of the single project to obtain the average comprehensive effect of the technology specifically includes:

[0064] Based on the comprehensive evaluation results of individual projects, the technologies are grouped into development technologies, and the average comprehensive effects of the technologies are evaluated and ranked;

[0065] Use histogram and quartile analysis to analyze the distribution of scores of individual items of the technology and grasp the overall effect of the technology.

[0066] The present invention provides a general oilfield enhanced oil recovery technology effect evaluation method, the evaluation method comprising: calculating the evaluation index of the enhanced oil recovery project; determining the weight of the evaluation index; performing a comprehensive evaluation of a single project according to the evaluation index and the weight of the evaluation index; and obtaining the average comprehensive effect of the technology based on the comprehensive evaluation of the single project. Placing different types of technologies on the same platform for evaluation solves the problem of comparability of different types of technologies, objectively gives the effects of different types of oil reservoir enhanced oil recovery technologies, and provides technical support for the selection of oilfield enhanced oil recovery technologies.

[0067] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0069] Figure 1 A flowchart of a general method for evaluating the effect of oilfield enhanced oil recovery technology provided by an embodiment of the present invention;

[0070] Figure 2 The distribution of comprehensive evaluation scores of projects related to a certain oilfield technology 5 in the embodiment of the present invention;

[0071] Figure 3 It is a quartile chart of the comprehensive evaluation scores of eight technologies of a certain oil field in the embodiment of the present invention. DETAILED DESCRIPTION

[0072] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0073] The terms "comprises" and "having" and any variations thereof in the description embodiments, claims and drawings of the present invention are intended to cover non-exclusive inclusions, for example, including a series of steps or units.

[0074] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0075] like Figure 1 As shown, the present invention proposes a general oilfield enhanced oil recovery technology effect evaluation method based on the conversion coverage of geological reserves, which fully considers the investment conditions of different projects, establishes a unified evaluation system and method applicable to various enhanced oil recovery technologies, and obtains a comprehensive and integrated evaluation result of the technology.

[0076] Since 2016, a certain oil field has implemented 76 EOR projects in its blocks, involving four types of reservoirs: monolithic, fault-block, low-permeability, and heavy oil, and eight EOR technologies. Due to the confidentiality of specific commercial data, the specific names of the technologies and projects in this example are hidden.

[0077] In step 101, the evaluation index of the enhanced oil recovery project is calculated. The evaluation indexes of the 76 enhanced oil recovery projects implemented in the oil field since 2016 are calculated, including the four evaluation indexes of the converted enhanced oil recovery, the converted enhanced oil recovery rate, the increase in SEC reserves per million investment, and the incremental ton oil cost of each project. The evaluation index results calculated for the project are shown in Table 1.

[0078] Table 1 Calculation results of project evaluation indicators of an oil field since 2016

[0079]

[0080]

[0081] In step 102, the CRITIC objective weighting method is used, and the weight of each evaluation index is determined in combination with the subjective requirements of oilfield development and operation. The specific calculation results are shown in Table 2.

[0082] Table 2 Weight table of project evaluation indicators of a certain oil field since 2016

[0083]

[0084]

[0085] In step 103, a single project is comprehensively evaluated. The TOPSIS method is used to comprehensively evaluate the effect of each project. The specific calculation results are shown in Table 3.

[0086] Table 3 Comprehensive evaluation results of projects in an oil field since 2016

[0087]

[0088]

[0089] In step 104, the enhanced oil recovery technologies are grouped and evaluated. The comprehensive evaluation results of all projects involving the same technology are numerically averaged, and the specific results are shown in Table 4.

[0090] Table 4 Collection results and ranking of 8 technical comprehensive evaluations implemented in an oil field since 2016

[0091] Technology Type Comprehensive evaluation results Ranking Technology 1 0.4080 5 Technique 2 0.4014 6 Technique 3 0.4176 7 Technique 4 0.3492 8 Technique 5 0.5384 1 Technique 6 0.5243 2 Technology 7 0.4169 4 Technique 8 0.4403 3

[0092] Through calculation, the comprehensive evaluation results and rankings of each enhanced oil recovery technology can be obtained. Technology 5, Technology 6, and Technology 8 have higher scores, indicating that from the technical and economic perspectives, the comprehensive effects of these three technologies are better than other technologies. Subsequently, a probability distribution diagram of the comprehensive evaluation results of a certain technology is made (see Figure 2 , taking technology 5 as an example) and the quartile chart of the eight technologies (see Figure 3 ), and more intuitively get the distribution of scores of different technologies. For example, the overall effect of technology 4 ranks the lowest among the 8 technologies, and the technical effect is unstable, with an abnormally low value. Although the overall effect of technology 2 is different from other technologies, the distribution range is very concentrated, indicating that the effect is very stable. In actual application, oil fields can give priority to implementing technology 5 with a higher score, so as to achieve Figure 2 , Figure 3 It can be seen that the scores are relatively stable, with a large proportion of high scores, which will achieve better results in actual production.

[0093] Beneficial effects: The present invention establishes an effect evaluation method based on the conversion coverage of geological reserves, which is generally applicable to various types of enhanced oil recovery technologies. In view of the input-output characteristics of different types of enhanced oil recovery technologies, innovative evaluation indicators and evaluation methods applicable to various technologies are developed, and different types of technologies are evaluated on the same platform, which solves the problem of comparability of different types of technologies, objectively gives the effects of different types of reservoir enhanced oil recovery technologies, and provides technical support for the selection of oilfield enhanced oil recovery technologies.

[0094] The above specific implementation methods further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific implementation methods of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A general method for evaluating the effect of oilfield enhanced oil recovery technology, characterized in that: The evaluation method includes: Calculate evaluation indicators for enhanced oil recovery projects; Determining the weight of the evaluation index; Performing a comprehensive evaluation of a single project according to the evaluation indicators and the evaluation indicator weights; The comprehensive evaluation of the single projects is used as the basis for aggregation to obtain the average comprehensive effect of the technology.

2. A general oilfield enhanced oil recovery technology effect evaluation method according to claim 1, characterized in that: The evaluation indexes for calculating the enhanced oil recovery project specifically include: converted enhanced oil recovery, converted enhanced oil recovery rate, increased SEC reserves per million investment and incremental ton oil cost.

3. A general oilfield enhanced oil recovery technology effect evaluation method according to claim 2, characterized in that: The calculation steps for converting the enhanced oil recovery factor specifically include: It is defined as the ratio of the cumulative oil production during the project evaluation period to the geological reserves covered by the project, which represents the contribution of technology to long-term production supply; In the formula, E z To convert the enhanced oil recovery factor, %; Q n is the cumulative oil increase, 10 4 t;N z To calculate the geological reserves, 10 4 t;q yi For projects with annual oil production, 10 4 t;q wi There is no project with annual oil production, 10 4 t; Among them, the conversion of geological reserves is a variable defined to solve the problem that different technical inputs, scales and workloads are different, and the simple evaluation of the final effect is not comparable; According to the input-output characteristics of the technology, there are three cases for calculating the converted geological reserves: New well-based technology: Measures-based technology: Technologies focusing on long-term investment: Among them, N z To calculate the geological reserves, 10 4 t; N is geological reserves, 10 4 t;n o is the number of crude oil wells; n w is the number of raw water wells; n n is the number of newly drilled oil and water wells; n c is the number of measures; n z is the number of wells injected with polymer; n s It is the number of effective oil wells after polymer injection.

4. A general oilfield enhanced oil recovery technology effect evaluation method according to claim 2, characterized in that: The calculation steps for converting the increased oil recovery rate specifically include: It is defined as the ratio of the average annual oil production increase during the peak period of the project to the converted geological reserves, which represents the contribution of technology to short-term production supply. Different types of technologies have different effectiveness characteristics and validity periods. Some technologies take effect quickly, while others have a lag period. The annual average oil increase value norms for the peak period of effectiveness are determined respectively; The technology mainly based on new wells is the oil production in the second year after the implementation of the new wells; the technology mainly based on measures is the oil production increase in the year after the measures are implemented; the technology mainly based on continuous investment is the average annual oil production increase from the peak of effectiveness to the year when investment is stopped; In the formula, v z To convert the increase in oil production rate, %; q nz is the average annual increase in oil production during the peak period, 10 4 t.

5. A general oilfield enhanced oil recovery technology effect evaluation method according to claim 2, characterized in that: The calculation method of increasing SEC reserves by one million investment specifically includes: It is defined as the ratio of the project's increased SEC reserves to the one-time investment of one million yuan, which represents the contribution of one-time technology investment to the increase in SEC reserves; There are three types of EOR technologies: new well drilling, production increase measures, and continuous investment. The initial one-time investment varies greatly. This indicator is defined to evaluate the effect of the technology from the perspective of the contribution of the one-time investment. Where N sm Increase SEC reserves for 1 million investment, 10 4 t / 10 6 Yuan, N s Increase SEC reserves for the evaluation period, 10 4 t; P is the one-time investment, including drilling investment, operating costs, and pharmaceutical costs, 10 6 Yuan.

6. A general oilfield enhanced oil recovery technology effect evaluation method according to claim 2, characterized in that: The incremental ton oil cost specifically includes: It is defined as the ratio of the additional cost of the enhanced oil recovery technology to the cumulative oil, which represents the cost of the additional production of the project; Among them, C d is the incremental oil cost per ton, RMB / t; C pz The additional cost for the evaluation period; q p is the oil production increase during the evaluation period; I is the investment; C zt is the additional cost in year t; q is the additional oil volume in year t; n is the year of the evaluation period; i is the discount rate; The projects are classified according to the enhanced oil recovery technologies they apply, and the relevant parameters are substituted into the indicator calculation formulas of different types of technologies to obtain the project evaluation indicator results.

7. A general oilfield enhanced oil recovery technology effect evaluation method according to claim 1, characterized in that: Determining the evaluation index weight specifically includes: The CRITIC objective weighting method is selected to calculate the indicator weights. The objective weights of the indicators are comprehensively measured based on the comparative strength of the evaluation indicators and the conflicts between the indicators. The variability of the indicators is considered while taking into account the correlation between the indicators. The CRITIC objective weighting method requires dimensionless processing of each indicator. The variability of the indicator is expressed in the form of standard deviation, the conflict of the indicator is expressed by the correlation coefficient, and the information content C is expressed in the form of standard deviation. j The larger it is, the greater the role of the jth evaluation index in the entire evaluation index system, and the more weight is assigned; In the formula, C j is the information content of the jth evaluation index; S j is the standard deviation of the jth index; P is the number of evaluation indicators; r ij is the correlation coefficient between the i-th evaluation index and the j-th evaluation index; So the objective weight W of the jth indicator j for: Among them, W j is the objective weight of the jth indicator; The TOPSIS method was used to calculate the comprehensive evaluation scores of four indicators, namely, single project converted improved recovery factor, converted improved oil production rate, increased SEC reserves per million investment, and incremental ton of oil cost.

8. A general oilfield enhanced oil recovery technology effect evaluation method according to claim 1, characterized in that: The comprehensive evaluation of a single project according to the evaluation index and the evaluation index weight specifically includes: The TOPSIS method first normalizes the original matrix and then standardizes it; Define the distance between the i-th evaluation object and the maximum value: In the formula, is the distance between the ith evaluation object and the maximum value; m is the number of evaluation indicators; is the maximum value of the jth evaluation index; z ij is the value of the jth evaluation index of the i-th evaluation object; Define the distance between the i-th evaluation object and the minimum value: In the formula, is the distance between the i-th evaluation object and the minimum value; is the minimum value of the jth evaluation index; Calculate the degree of closeness between the i-th evaluation object and the optimal solution: In the formula, S i is the score of the i-th evaluation object; S i The value is between 0 and 1. The closer it is to 1, the closer the evaluation object is to the optimal level.

9. A general oilfield enhanced oil recovery technology effect evaluation method according to claim 1, characterized in that: The comprehensive evaluation of a single project based on the evaluation index and the evaluation index weight also includes: using the TOPSIS method to calculate the comprehensive evaluation score of the single project's converted improved recovery factor, converted improved oil production rate, million-dollar investment increase in SEC reserves, and incremental ton of oil cost indicators.

10. A general oilfield enhanced oil recovery technology effect evaluation method according to claim 1, characterized in that: The above-mentioned collection based on the comprehensive evaluation of the single project to obtain the average comprehensive effect of the technology specifically includes: Based on the comprehensive evaluation results of individual projects, the technologies are grouped into development technologies, and the average comprehensive effects of the technologies are evaluated and ranked; Use histogram and quartile analysis to analyze the distribution of scores of individual items of the technology and grasp the overall effect of the technology.

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