Dynamic analysis method and system for oil reservoir water-displacing-oil development

Abstract

The invention provides an oil reservoir water-flooding oil development dynamic analysis method and system, and relates to the technical field of oil-gas field development.The method includes the steps that development data of an oil reservoir area within seven days are obtained, water-flooding development characteristic parameters are calculated, and an oil-flooding efficiency index, an injection-production balance index and a water-flooding characteristic index are generated based on the characteristic parameters; and further generating an oil reservoir recovery index, setting an oil reservoir recovery threshold value, comparing the oil reservoir recovery index with the threshold value, judging whether the oil reservoir region reaches an expected recovery target or not, further classifying the region into a low-efficiency or high-efficiency displacement region, and formulating corresponding optimization strategies for the low-efficiency and high-efficiency displacement regions based on an analysis result to perform collaborative management. According to the method, low-efficiency and high-efficiency displacement area classification based on the oil reservoir recovery index is realized by analyzing the oil reservoir area development data and calculating the characteristic parameters, the optimization strategy is formulated, and the oil field development efficiency and recovery efficiency are improved.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas field development, and in particular to a dynamic analysis method and system for oil reservoir water drive development. Background Art

[0002] Reservoir water flooding is a commonly used technology for improving oil and gas field development. It injects water into the reservoir to displace crude oil, thereby replenishing reservoir energy and maintaining reservoir pressure. As oil field development enters the middle and late stages, traditional water flooding development methods face a series of problems in the high water content stage, such as injection-production imbalance, increased inefficient displacement areas, and serious interlayer crossflow. This has led to more and more attention to the application of refined management technology and dynamic analysis methods to improve water flooding efficiency and extend the economic life of oil fields.

[0003] In the future, as the development of oil and gas resources becomes more difficult, water flooding technology will develop in the direction of intelligence, digitization and refinement. Combining big data, artificial intelligence and reservoir modeling technology, dynamic monitoring and optimization of water flooding development process will become a key research direction. In addition, for the development of complex oil reservoirs, more efficient adjustment strategies and supporting technologies need to be developed to achieve efficient utilization of inefficient displacement areas. These advances will further promote the improvement of oilfield development efficiency and provide more reliable technical support for global energy development.

[0004] In the existing technology, water-drive oil development methods often rely on a single indicator or static evaluation method when analyzing the development status of oil reservoirs, lacking a comprehensive evaluation of the actual development process of the oil reservoir and real-time dynamic adjustment. This leads to the inability to effectively monitor changes in key factors such as water drive efficiency, injection-production balance, and water drive characteristics during the development process, making it difficult to flexibly adjust the optimization strategy, and unable to accurately guide the management and development of different oil reservoir areas, resulting in unsatisfactory oil reservoir development results.

[0005] In addition, existing technologies often use a single empirical formula or static model to optimize water-flooding development, ignoring the differences in reservoir regions and dynamic changes during development. Traditional methods are usually unable to effectively distinguish between high-efficiency displacement areas and low-efficiency displacement areas, so there is blindness in regional management. Especially in terms of resource allocation and well network layout in low-efficiency displacement areas and high-efficiency displacement areas, there is a lack of optimization strategies based on dynamic data and comprehensive analysis results, resulting in waste of resources or failure to fully tap the potential of reservoirs.

[0006] Therefore, it is necessary to provide a dynamic analysis method and system for reservoir water flooding development to solve the above problems.

[0007] The above information disclosed in this Background section is only for enhancement of understanding of the background of the present disclosure and therefore it may contain information that does not constitute the prior art that is already known to one of ordinary skill in the art. Summary of the invention

[0008] The object of the present invention is to provide a method and system for dynamic analysis of water flooding development in oil reservoirs to solve the problems raised in the above-mentioned background technology.

[0009] To achieve the above object, the present invention provides the following technical solutions:

[0010] A dynamic analysis method for water flooding development in oil reservoirs, comprising the following specific steps:

[0011] Step 1: Obtain development data of the reservoir area to be analyzed within seven days, and calculate water drive development characteristic parameters based on the development data, including cumulative oil production, cumulative water injection, water content of production wells, and water-oil ratio of production wells;

[0012] Step 2: Generate an index characterizing the reservoir development status based on the calculated water drive development characteristic parameters, including an oil recovery efficiency index, an injection-production balance index, and a water drive characteristic index, and generate a reservoir recovery index based on the generated oil recovery efficiency index, injection-production balance index, and water drive characteristic index;

[0013] Step 3: Establish a reservoir recovery threshold, compare the generated reservoir recovery index with the reservoir recovery threshold, and determine whether the expected target of reservoir recovery has been achieved. If the expected target has not been achieved, the reservoir area to be analyzed is set as an inefficient displacement area. If the expected target has been exceeded, the reservoir area to be analyzed is set as an efficient displacement area.

[0014] Step 4: Based on the analysis results in step 3, formulate optimization strategies for the low-efficiency displacement area and the high-efficiency displacement area, and coordinately manage the low-efficiency displacement area and the high-efficiency displacement area.

[0015] Furthermore, the characteristic parameters of water flooding development are calculated based on the following method:

[0016] The daily oil production of the reservoir area to be analyzed within seven days is analyzed to calculate the cumulative oil production based on the formula:

[0017]

[0018] Among them, N p Indicates the cumulative oil production in seven days, q o (t) is the daily oil production data of the tth day in seven days, t is the index of the production day, t∈[1,7];

[0019] The daily water injection volume of the reservoir area to be analyzed within seven days is analyzed to calculate the cumulative water injection volume based on the formula:

[0020]

[0021] Among them, W intIndicates the cumulative water injection volume in seven days, q w int (t) is the daily water injection volume on the tth day in seven days;

[0022] The water content of the production well is calculated based on the seven-day cumulative water production and cumulative oil production, based on the following formula:

[0023]

[0024] Among them, f w represents the water content of the production well, is the cumulative water production for seven days, q w prood (t) is the daily water production on the tth day in seven days;

[0025] The ratio of the seven-day cumulative oil production to the cumulative water production is the water-oil ratio of the production well, based on the formula:

[0026]

[0027] Wherein, WOR represents the water-oil ratio of the production well.

[0028] Furthermore, an index characterizing the reservoir development status is generated based on the following method:

[0029] The oil displacement efficiency index is used to characterize the efficiency of crude oil displacement during water injection development. The index is essentially the ratio between the cumulative oil production and the cumulative water injection volume. After adjustment, it reflects the changing law of water injection efficiency. The formula for calculating the oil displacement efficiency index is:

[0030]

[0031] Among them, E o represents the oil recovery efficiency index;

[0032] The injection-production balance index is used to characterize the dynamic balance relationship between water injection volume and oil production and water production. The formula for calculating the injection-production balance index is:

[0033]

[0034] Among them, R i It represents the injection-production balance index;

[0035] The water drive characteristic index is used to characterize the water utilization efficiency in water drive development and the degree to which the reservoir enters the high water cut period. Based on the relationship between the cumulative water injection volume and the water-oil ratio, the displacement law in the water drive process is analyzed. The formula for calculating the water drive characteristic index is:

[0036]

[0037] Wherein, WPI stands for water drive performance index.

[0038] Furthermore, the reservoir recovery index is comprehensively generated based on the generated oil recovery efficiency index, injection-production balance index and water drive characteristic index, and the formula is as follows:

[0039]

[0040] Where Ne represents the reservoir recovery index, R 理想 It indicates the ideal value of injection-production balance index.

[0041] Furthermore, a reservoir recovery threshold is set, and the generated reservoir recovery index is compared with the reservoir recovery threshold to determine whether the expected target of reservoir recovery has been achieved. The logic formula is as follows:

[0042]

[0043] Among them, Q is a logical value for judging whether the expected target of oil reservoir recovery is achieved. When Q=0, it means that the oil reservoir area to be analyzed is an inefficient displacement area, and when Q=1, it means that the oil reservoir area to be analyzed is an efficient displacement area.

[0044] Furthermore, based on the analysis results in step 3, optimization strategies are formulated for the low-efficiency displacement area and the high-efficiency displacement area, respectively, and the low-efficiency displacement area and the high-efficiency displacement area are managed in a coordinated manner. The method is as follows:

[0045] First, for the optimization of water injection volume, according to the injection-production balance index R i To determine the water injection rate, if the water injection rate is too high relative to the production rate in the high-efficiency displacement area, the water injection rate should be reduced to avoid the aggravation of the fingering effect; if the reservoir shows insufficient fluid energy in the low-efficiency displacement area, the water injection rate should be increased to ensure a reasonable displacement pressure and improve oil recovery efficiency;

[0046] Secondly, optimize the well network structure, improve the water drive efficiency, make the fluid flow in different areas more balanced, adjust the spacing between water injection wells and production wells for the high-efficiency displacement area, avoid water channeling caused by over-development, adopt irregular well network optimization layout, prevent the formation of high-speed channels, make the water drive more uniform, and in the high water-content well area, reduce the injection-production ratio, reduce the water phase flow rate, reduce invalid circulation, and improve the overall recovery rate; for the inefficient displacement area, adopt a supplementary well network strategy, appropriately increase water injection wells in the inefficient displacement area, improve the range of influence, lay horizontal wells or multi-branch wells, improve the recovery efficiency of low permeability areas, and make the fluid flow more uniform;

[0047] Manage the production wells and make adjustments to their operation to optimize the oil-water ratio and improve oil recovery efficiency. For high-efficiency displacement areas, if the water-oil ratio is high, it indicates that the high water-cut period has arrived, and the production rate should be reduced to prevent unstable flow of high-water-cut oil wells and reduce ineffective water production. Adopt stratified oil production technology to reasonably control the liquid production of different layers to prevent further flooding of high-permeability layers. For inefficient areas, if the production of production wells is low, it is necessary to increase the oil production rate, improve the fluid driving force, adopt intermittent oil production or adjust the pumping unit parameters, optimize the liquid production structure, and improve the fluid utilization level in low-permeability areas.

[0048] The present invention further provides a reservoir water flooding development dynamic analysis system, the dynamic analysis system is used to execute the above-mentioned reservoir water flooding development dynamic analysis method, comprising:

[0049] A characteristic parameter calculation module, which is used to obtain development data of the reservoir area to be analyzed within seven days, and calculate water drive development characteristic parameters based on the development data, including cumulative oil production, cumulative water injection, water content of production wells, and water-oil ratio of production wells;

[0050] A development status index generation and recovery index calculation module, which generates an index characterizing the reservoir development status based on the calculated water drive development characteristic parameters, including an oil recovery efficiency index, an injection-production balance index, and a water drive characteristic index, and comprehensively generates an oil reservoir recovery index based on the generated oil recovery efficiency index, injection-production balance index, and water drive characteristic index;

[0051] A recovery target evaluation and regional classification module, which is used to set a reservoir recovery threshold, compare the generated reservoir recovery index with the reservoir recovery threshold, and determine whether the expected target of reservoir recovery has been achieved. If the expected target has not been achieved, the reservoir area to be analyzed is set as a low-efficiency displacement area; if the expected target has been exceeded, the reservoir area to be analyzed is set as a high-efficiency displacement area;

[0052] The optimization strategy formulation and regional collaborative management module formulates optimization strategies for the low-efficiency displacement area and the high-efficiency displacement area based on the analysis results in step 3, and performs collaborative management on the low-efficiency displacement area and the high-efficiency displacement area.

[0053] Compared with the prior art, the present invention has the following beneficial effects:

[0054] The present invention solves the inaccuracy problem caused by static evaluation or single index evaluation in the prior art by introducing an analysis method for dynamic calculation based on development data within seven days. Traditional methods usually rely on a single, periodic evaluation index, which is difficult to reflect the complex changes in the reservoir development process in real time. The present invention generates an oil recovery efficiency index, an injection-production balance index and a water recovery characteristic index by dynamically calculating characteristic parameters such as cumulative oil production, water injection volume, water content of production wells, and water-oil ratio, thereby providing a more accurate and real-time reservoir development status evaluation and a scientific basis for the optimal management of the reservoir.

[0055] In addition, the present invention solves the extensive management problems that often exist in the prior art by combining multi-dimensional comprehensive indexes such as oil recovery efficiency, injection-production balance and water drive characteristics. Traditional methods often use a single, simple oil recovery efficiency index, which makes it difficult to accurately distinguish the development efficiency of different reservoir areas. By setting the reservoir recovery threshold and comparing it with the recovery index, the reservoir area is systematically divided into high-efficiency and low-efficiency displacement areas, and optimization strategies are formulated for different areas, making water injection adjustment, well network layout and production well management more accurate, greatly improving the recovery efficiency of the reservoir and the stability of long-term development;

[0056] The present invention realizes a more accurate and real-time assessment of reservoir development status through dynamic calculation methods and multi-dimensional comprehensive indexes, thereby improving recovery efficiency and development stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 It is a schematic diagram of the overall method flow of the present invention.

[0058] Figure 2 It is a schematic diagram of the system module flow of the present invention. DETAILED DESCRIPTION

[0059] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments.

[0060] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0061] Example:

[0062] See also Figure 1 , a dynamic analysis method for water flooding development of oil reservoirs, the specific steps include:

[0063] Step 1: Obtain development data of the reservoir area to be analyzed within seven days, and calculate water drive development characteristic parameters based on the development data, including cumulative oil production, cumulative water injection, water content of production wells, and water-oil ratio of production wells;

[0064] Step 2: Generate an index characterizing the reservoir development status based on the calculated water drive development characteristic parameters, including an oil recovery efficiency index, an injection-production balance index, and a water drive characteristic index, and generate a reservoir recovery index based on the generated oil recovery efficiency index, injection-production balance index, and water drive characteristic index;

[0065] Step 3: Establish a reservoir recovery threshold, compare the generated reservoir recovery index with the reservoir recovery threshold, and determine whether the expected target of reservoir recovery has been achieved. If the expected target has not been achieved, the reservoir area to be analyzed is set as an inefficient displacement area. If the expected target has been exceeded, the reservoir area to be analyzed is set as an efficient displacement area.

[0066] Step 4: Based on the analysis results in step 3, formulate optimization strategies for the low-efficiency displacement area and the high-efficiency displacement area, and coordinately manage the low-efficiency displacement area and the high-efficiency displacement area.

[0067] It should be noted that by accurately calculating the cumulative oil production, cumulative water injection, water content of production wells and water-oil ratio, we can fully understand the development effect and stability of the reservoir. These parameters can not only reflect the production performance of the oil field, but also provide a scientific basis for subsequent development decisions, optimize water drive development strategies, thereby improving recovery, reducing resource waste, and ensuring the economic and long-term sustainability of oil field development.

[0068] Therefore, it is necessary to calculate the characteristic parameters of water flooding development, based on the following method:

[0069] The daily oil production of the reservoir area to be analyzed within seven days is analyzed to calculate the cumulative oil production based on the formula:

[0070]

[0071] Among them, N p Indicates the cumulative oil production in seven days, q o (t) is the daily oil production data of the tth day in seven days, t is the index of the production day, t∈[1,7];

[0072] The daily water injection volume of the reservoir area to be analyzed within seven days is analyzed to calculate the cumulative water injection volume based on the formula:

[0073]

[0074] Among them, W int Indicates the cumulative water injection volume in seven days, q w int (t) is the daily water injection volume on the tth day in seven days;

[0075] The water content of the production well is calculated based on the seven-day cumulative water production and cumulative oil production, based on the following formula:

[0076]

[0077] Among them, f w represents the water content of the production well, is the cumulative water production for seven days, q w prood (t) is the daily water production on the tth day in seven days;

[0078] The ratio of the seven-day cumulative oil production to the cumulative water production is the water-oil ratio of the production well, based on the formula:

[0079]

[0080] Wherein, WOR represents the water-oil ratio of the production well.

[0081] It should be noted that the oil displacement efficiency index can measure the displacement efficiency of crude oil during the water injection process, reflect the recovery effect of the reservoir and the changing law of water drive efficiency, and provide a basis for improving the recovery rate. The injection-production balance index helps optimize the injection-production system by evaluating the dynamic balance between the water injection volume and the oil production and water production, and prevents inefficient development caused by excessive water injection or imbalance between injection and production. The water drive characteristic index is used to analyze the water utilization efficiency during the water drive process, identify the degree to which the reservoir enters the high water cut period, and provide decision support for adjusting the development method and delaying the high water cut period. The comprehensive use of these indices can not only improve the level of refined management of water drive development, but also reduce development costs and improve the economic benefits and sustainable development capabilities of oil fields.

[0082] Therefore, it is necessary to generate an index to characterize the reservoir development status, based on the following method:

[0083] The oil displacement efficiency index is used to characterize the efficiency of crude oil displacement during water injection development. The index is essentially the ratio between the cumulative oil production and the cumulative water injection volume. After adjustment, it reflects the changing law of water injection efficiency. The formula for calculating the oil displacement efficiency index is:

[0084] The oil displacement efficiency index is used to characterize the efficiency of crude oil displacement during water injection development. The index is essentially the ratio between the cumulative oil production and the cumulative water injection volume. After adjustment, it reflects the changing law of water injection efficiency. The formula for calculating the oil displacement efficiency index is:

[0085]

[0086] Among them, E o represents the oil recovery efficiency index; in the above formula, the cumulative oil production N p The larger the oil recovery efficiency index E o The higher the value, the higher the displacement efficiency of crude oil under the same water flooding condition; and the cumulative water injection volume The higher the oil recovery efficiency index E o The smaller the water content of the production well, the lower the oil displacement efficiency. w The smaller the displacement efficiency, the greater the oil recovery under the same water flooding conditions. Therefore, the oil displacement efficiency index E o The bigger the better, which means that a high oil recovery efficiency index means that more crude oil can be displaced under unit water injection volume, indicating that the development effect of the oil reservoir is good and the crude oil recovery rate is high. It also means that the injected water can effectively drive out the crude oil, and the utilization efficiency of water resources is relatively high, reducing unnecessary water loss in the water flooding process.

[0087] The injection-production balance index is used to characterize the dynamic balance relationship between water injection volume and oil production and water production. The formula for calculating the injection-production balance index is:

[0088]

[0089] Among them, R i represents the injection-production balance index; in the above formula, W int The larger the R i The larger the value, the more water is injected, which will improve the displacement effect of crude oil. p The larger the R i The smaller the value, the higher the oil production and the less water injection volume, which may lead to insufficient water injection and affect the displacement effect. p The larger the R i The smaller it is, this indicates that if the water production is too high, it may affect the effectiveness of water injection and lead to insufficient water injection;

[0090] If R i =R 理想 =1, indicating that the water injection volume and the total output are balanced, that is, the injected water volume can effectively promote the production of crude oil and water, indicating that the development effect is good; if R i >1, indicating that the water injection volume exceeds the total output, which may lead to flooding, reflecting that the development strategy may need to be adjusted to optimize the relationship between water injection and output; if R i <1, indicating that the water injection volume is insufficient to effectively displace crude oil, which may indicate that more water injection is needed to improve the recovery factor of the oil field.

[0091] The water drive characteristic index is used to characterize the water utilization efficiency in water drive development and the degree to which the reservoir enters the high water cut period. Based on the relationship between the cumulative water injection volume and the water-oil ratio, the displacement law in the water drive process is analyzed. The formula for calculating the water drive characteristic index is:

[0092]

[0093] Wherein, WPI represents the water drive characteristic index; in the above formula, Indicates the amount of water injection required for unit oil production, reflecting the efficiency of water utilization. It can measure how much water injection is required to obtain a certain amount of oil in a certain period of time; if If WOR decreases, WPI will increase, which means that in order to obtain the same amount of oil, the amount of water injected is reduced, reflecting the increased water utilization efficiency; if WOR decreases, WPI will increase, which means that the water production corresponding to the unit oil production is reduced, the water utilization efficiency is increased, and the efficiency of displacing crude oil is increased; therefore, the larger the WPI, the better, indicating that under a certain amount of water injection, the achieved oil production is relatively high, the water utilization efficiency is good, and the displacement effect is significant.

[0094] It should be noted that the reservoir recovery index is a comprehensive indicator that evaluates the development status of the reservoir by combining oil recovery efficiency, injection-production balance and water drive characteristics. It is of great significance to optimize injection-production management, improve recovery rate and enhance economic benefits. The index can monitor the development dynamics of the reservoir in real time, identify problems at an early stage, optimize and adjust the development plan, thereby improving water drive efficiency, extending the reservoir development cycle, realizing refined management and sustainable development of the oil field, and ultimately improving the overall economic benefits and recovery rate of the oil field.

[0095] Therefore, it is necessary to comprehensively generate the reservoir recovery index based on the generated oil recovery efficiency index, injection-production balance index and water drive characteristic index. The formula is as follows:

[0096]

[0097] Where Ne represents the reservoir recovery index, R 理想 Indicates the ideal value of the injection-production balance index; in the above formula, E o The increase of WPI and Ne indicates that the water utilization efficiency is high and the waste of water resources is small during the water injection process. i -R 理想 The smaller | is, the higher the R i The closer it is to the ideal value of 1, the better the balance between water injection and output, which reduces inefficient development caused by insufficient or excessive water injection. The denominator is added with 1 to avoid the situation where R i The ideal value case results in the denominator being 0, which leads to Ne being 0.

[0098] It should be noted that setting a reservoir recovery threshold and comparing it with the reservoir recovery index to determine whether the reservoir has reached the expected recovery target is an important step in reservoir development management. Through this logical formula, it can be determined whether the region is in an efficient or inefficient displacement zone, which helps optimize the reservoir development strategy. When the reservoir recovery index is greater than or equal to the threshold, it indicates that the reservoir has a good oil recovery effect and is in an efficient displacement zone, indicating that the effect of reservoir development is in line with expectations; conversely, when the reservoir recovery index is lower than the threshold, it indicates that the recovery effect of the area is poor and measures need to be taken to improve it. Therefore, setting a reservoir recovery threshold can help decision makers identify inefficient areas in a timely manner and take targeted improvement measures, thereby improving the overall recovery efficiency and economic benefits of the oil field.

[0099] Therefore, it is necessary to set up a reservoir recovery threshold, compare the generated reservoir recovery index with the reservoir recovery threshold, and judge whether the expected target of reservoir recovery is achieved. The logical formula is as follows:

[0100]

[0101] Among them, Q is a logical value for judging whether the expected target of oil reservoir recovery is achieved. When Q=0, it means that the oil reservoir area to be analyzed is an inefficient displacement area, and when Q=1, it means that the oil reservoir area to be analyzed is an efficient displacement area.

[0102] It should be noted that

[0103] Therefore, it is necessary to formulate optimization strategies for the low-efficiency displacement area and the high-efficiency displacement area based on the analysis results in step 3, and coordinately manage the low-efficiency displacement area and the high-efficiency displacement area. The method is based on:

[0104] First, for the optimization of water injection volume, according to the injection-production balance index R i To determine the water injection rate, if the water injection rate is too high relative to the production rate in the high-efficiency displacement area, the water injection rate should be reduced to avoid the aggravation of the fingering effect; if the reservoir shows insufficient fluid energy in the low-efficiency displacement area, the water injection rate should be increased to ensure a reasonable displacement pressure and improve oil recovery efficiency;

[0105] Secondly, optimize the well network structure, improve the water drive efficiency, make the fluid flow in different areas more balanced, adjust the spacing between water injection wells and production wells for the high-efficiency displacement area, avoid water channeling caused by over-development, adopt irregular well network optimization layout, prevent the formation of high-speed channels, make the water drive more uniform, and in the high water-content well area, reduce the injection-production ratio, reduce the water phase flow rate, reduce invalid circulation, and improve the overall recovery rate; for the inefficient displacement area, adopt a supplementary well network strategy, appropriately increase water injection wells in the inefficient displacement area, improve the range of influence, lay horizontal wells or multi-branch wells, improve the recovery efficiency of low permeability areas, and make the fluid flow more uniform;

[0106] Manage the production wells and make adjustments to their operation to optimize the oil-water ratio and improve oil recovery efficiency. For high-efficiency displacement areas, if the water-oil ratio is high, it indicates that the high water-cut period has arrived, and the production rate should be reduced to prevent unstable flow of high-water-cut oil wells and reduce ineffective water production. Adopt stratified oil production technology to reasonably control the liquid production of different layers to prevent further flooding of high-permeability layers. For inefficient areas, if the production of production wells is low, it is necessary to increase the oil production rate, improve the fluid driving force, adopt intermittent oil production or adjust the pumping unit parameters, optimize the liquid production structure, and improve the fluid utilization level in low-permeability areas.

[0107] See also Figure 2 The present invention also provides a dynamic analysis system for oil reservoir water flooding development, the dynamic analysis system is used to execute the above-mentioned oil reservoir water flooding development dynamic analysis method, comprising:

[0108] A characteristic parameter calculation module, which is used to obtain development data of the reservoir area to be analyzed within seven days, and calculate water drive development characteristic parameters based on the development data, including cumulative oil production, cumulative water injection, water content of production wells, and water-oil ratio of production wells;

[0109] A development status index generation and recovery index calculation module, which generates an index characterizing the reservoir development status based on the calculated water drive development characteristic parameters, including an oil recovery efficiency index, an injection-production balance index, and a water drive characteristic index, and comprehensively generates an oil reservoir recovery index based on the generated oil recovery efficiency index, injection-production balance index, and water drive characteristic index;

[0110] A recovery target evaluation and regional classification module, which is used to set a reservoir recovery threshold, compare the generated reservoir recovery index with the reservoir recovery threshold, and determine whether the expected target of reservoir recovery has been achieved. If the expected target has not been achieved, the reservoir area to be analyzed is set as a low-efficiency displacement area; if the expected target has been exceeded, the reservoir area to be analyzed is set as a high-efficiency displacement area;

[0111] The optimization strategy formulation and regional collaborative management module formulates optimization strategies for the low-efficiency displacement area and the high-efficiency displacement area based on the analysis results in step 3, and performs collaborative management on the low-efficiency displacement area and the high-efficiency displacement area.

[0112] The above formulas are all dimensionless and numerical calculations. The formula is a formula for the most recent real situation obtained by collecting a large amount of data and performing software simulation. The preset parameters in the formula are set by technicians in this field according to actual conditions.

[0113] The above embodiments may be implemented in whole or in part by software, hardware, firmware or any other combination thereof. When implemented by software, the above embodiments may be implemented in whole or in part in the form of a computer program product. Those skilled in the art may appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein may be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed by hardware or software methods depends on the specific application and design constraints of the technical solution.

[0114] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, and may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0115] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application.

Claims

1. A dynamic analysis method for water flooding development in oil reservoirs, characterized in that: The specific steps include: Step 1: Obtain development data of the reservoir area to be analyzed within seven days, and calculate water drive development characteristic parameters based on the development data, including cumulative oil production, cumulative water injection, water content of production wells, and water-oil ratio of production wells; Step 2: Generate an index characterizing the reservoir development status based on the calculated water drive development characteristic parameters, including an oil recovery efficiency index, an injection-production balance index, and a water drive characteristic index, and generate a reservoir recovery index based on the generated oil recovery efficiency index, injection-production balance index, and water drive characteristic index; Step 3: Establish a reservoir recovery threshold, compare the generated reservoir recovery index with the reservoir recovery threshold, and determine whether the expected target of reservoir recovery has been achieved. If the expected target has not been achieved, the reservoir area to be analyzed is set as an inefficient displacement area. If the expected target has been exceeded, the reservoir area to be analyzed is set as an efficient displacement area. Step 4: Based on the analysis results in step 3, formulate optimization strategies for the low-efficiency displacement area and the high-efficiency displacement area, and coordinately manage the low-efficiency displacement area and the high-efficiency displacement area.

2. A reservoir water flooding development dynamic analysis method according to claim 1, characterized in that: The method for calculating the characteristic parameters of water flooding development is based on: The daily oil production of the reservoir area to be analyzed within seven days is analyzed to calculate the cumulative oil production based on the formula: Among them, N p Indicates the cumulative oil production in seven days, q o (t) is the daily oil production data of the tth day in seven days, t is the index of the production day, t∈[1,7]; The daily water injection volume of the reservoir area to be analyzed within seven days is analyzed to calculate the cumulative water injection volume based on the formula: Among them, W int Indicates the cumulative water injection volume in seven days, q w int (t) is the daily water injection volume on the tth day in seven days; The water content of the production well is calculated based on the seven-day cumulative water production and cumulative oil production, based on the following formula: Among them, f w represents the water content of the production well, is the cumulative water production for seven days, q w prood (t) is the daily water production on the tth day in seven days; The ratio of the seven-day cumulative oil production to the cumulative water production is the water-oil ratio of the production well, based on the formula: Wherein, WOR represents the water-oil ratio of the production well.

3. A reservoir water flooding development dynamic analysis method according to claim 2, characterized in that: The method used to generate the index characterizing the reservoir development status is: The oil displacement efficiency index is used to characterize the efficiency of crude oil displacement during water injection development. The index is essentially the ratio between the cumulative oil production and the cumulative water injection volume. After adjustment, it reflects the changing law of water injection efficiency. The formula for calculating the oil displacement efficiency index is: Among them, E o represents the oil recovery efficiency index; The injection-production balance index is used to characterize the dynamic balance relationship between water injection volume and oil production and water production. The formula for calculating the injection-production balance index is: Among them, R i It represents the injection-production balance index; The water drive characteristic index is used to characterize the water utilization efficiency in water drive development and the degree to which the reservoir enters the high water cut period. Based on the relationship between the cumulative water injection volume and the water-oil ratio, the displacement law in the water drive process is analyzed. The formula for calculating the water drive characteristic index is: Wherein, WPI stands for water drive performance index.

4. A reservoir water flooding development dynamic analysis method according to claim 3, characterized in that: The reservoir recovery index is generated based on the generated oil recovery efficiency index, injection-production balance index and water drive characteristic index. The formula is as follows: Where Ne represents the reservoir recovery index, R 理想 It indicates the ideal value of injection-production balance index.

5. A reservoir water flooding development dynamic analysis method according to claim 4, characterized in that: The reservoir recovery threshold is established, and the generated reservoir recovery index is compared with the reservoir recovery threshold to determine whether the expected target of reservoir recovery has been achieved. The logical formula is as follows: Among them, Q is a logical value for judging whether the expected target of oil reservoir recovery is achieved. When Q=0, it means that the oil reservoir area to be analyzed is an inefficient displacement area, and when Q=1, it means that the oil reservoir area to be analyzed is an efficient displacement area.

6. A reservoir water flooding development dynamic analysis method according to claim 1, characterized in that: Based on the analysis results in step 3, optimization strategies are formulated for the low-efficiency displacement area and the high-efficiency displacement area respectively, and the low-efficiency displacement area and the high-efficiency displacement area are managed in a coordinated manner. The method is based on: First, for the optimization of water injection volume, according to the injection-production balance index R i To determine the water injection rate, if the water injection rate is too high relative to the production rate in the high-efficiency displacement area, the water injection rate should be reduced to avoid the aggravation of the fingering effect; if the reservoir shows insufficient fluid energy in the low-efficiency displacement area, the water injection rate should be increased to ensure a reasonable displacement pressure and improve oil recovery efficiency; Secondly, optimize the well network structure, improve the water drive efficiency, make the fluid flow in different areas more balanced, adjust the spacing between water injection wells and production wells for the high-efficiency displacement area, avoid water channeling caused by over-development, adopt irregular well network optimization layout, prevent the formation of high-speed channels, make the water drive more uniform, and in the high water-content well area, reduce the injection-production ratio, reduce the water phase flow rate, reduce invalid circulation, and improve the overall recovery rate; for the inefficient displacement area, adopt a supplementary well network strategy, appropriately increase water injection wells in the inefficient displacement area, improve the range of influence, lay horizontal wells or multi-branch wells, improve the recovery efficiency of low permeability areas, and make the fluid flow more uniform; Manage the production wells and make adjustments to their operation to optimize the oil-water ratio and improve oil recovery efficiency. For high-efficiency displacement areas, if the water-oil ratio is high, it indicates that the high water-cut period has arrived, and the production rate should be reduced to prevent unstable flow of high-water-cut oil wells and reduce ineffective water production. Adopt stratified oil production technology to reasonably control the liquid production of different layers to prevent further flooding of high-permeability layers. For inefficient areas, if the production of production wells is low, it is necessary to increase the oil production rate, improve the fluid driving force, adopt intermittent oil production or adjust the pumping unit parameters, optimize the liquid production structure, and improve the fluid utilization level in low-permeability areas.

7. A dynamic analysis system for oil reservoir water flooding development, characterized in that: The dynamic analysis system is used to execute a dynamic analysis method for oil reservoir water flooding development according to any one of claims 1 to 6, comprising: A characteristic parameter calculation module, which is used to obtain development data of the reservoir area to be analyzed within seven days, and calculate water drive development characteristic parameters based on the development data, including cumulative oil production, cumulative water injection, water content of production wells, and water-oil ratio of production wells; A development status index generation and recovery index calculation module, which generates an index characterizing the reservoir development status based on the calculated water drive development characteristic parameters, including an oil recovery efficiency index, an injection-production balance index, and a water drive characteristic index, and comprehensively generates an oil reservoir recovery index based on the generated oil recovery efficiency index, injection-production balance index, and water drive characteristic index; A recovery target evaluation and regional classification module, which is used to set a reservoir recovery threshold, compare the generated reservoir recovery index with the reservoir recovery threshold, and determine whether the expected target of reservoir recovery has been achieved. If the expected target has not been achieved, the reservoir area to be analyzed is set as a low-efficiency displacement area; if the expected target has been exceeded, the reservoir area to be analyzed is set as a high-efficiency displacement area; The optimization strategy formulation and regional collaborative management module formulates optimization strategies for the low-efficiency displacement area and the high-efficiency displacement area based on the analysis results in step 3, and performs collaborative management on the low-efficiency displacement area and the high-efficiency displacement area.

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