A method for identifying high water consumption zones in oil reservoirs using streamline density

Abstract

The invention discloses a method for identifying a high water consumption layer zone of an oil reservoir by using streamline density, comprising: establishing a quantitative high water consumption layer zone determination standard by using the streamline density variation law, dividing the oil reservoir into layers and grids, calculating the streamline density of different grids, finding the maximum and minimum streamline density of each layer and the entire oil reservoir, dividing the grids with different water consumption degrees based on the dichotomy idea, and then calculating the maximum and minimum cumulative external water displacement multiples of different grids in the second potential high water consumption layer zone by a fuzzy comprehensive evaluation method, and then performing interval division, and finally, superimposing and calculating the streamline density and external water displacement multiple of the same grid, and comprehensively determining the high water consumption layer zone. The invention establishes a quantitative high water consumption layer zone determination method, accurately characterizes the distribution law of the high water consumption layer zone, and can also qualitatively observe the change of water content in the oil layer and the distribution law of the remaining oil, so as to provide a reference basis for the efficient development of water injection oil fields.

Description

Technical Field

[0001] The invention relates to a method for identifying a high water consumption layer zone in an oil reservoir by utilizing streamline density, and belongs to the technical field of petroleum geological exploration. Background Art

[0002] The present invention belongs to the field of oil development technology. When the oil reservoir enters the water injection development stage, it will be soaked and flushed by the injected water, resulting in changes in the reservoir pore structure and physical parameters. In addition, due to the influence of heterogeneity, the injected water is easy to advance along the high permeability section in the plane and vertical direction, forming a dominant seepage channel between the oil and water wells, in which the injected water is inefficiently or ineffectively circulated, with low utilization rate, which is not conducive to improving the sweep coefficient and oil recovery efficiency. Therefore, it is also called a high water consumption layer zone. In the mine, it manifests itself as a short waterless oil production period for oil wells, a sharp increase in water content, low oil production or even forced suspension of production, which seriously restricts the effect of oil reservoir development.

[0003] Therefore, in order to improve the development effect of subsequent water flooding in oil fields, it is of great significance to propose a method to identify high water consumption zones, describe the distribution characteristics of high water consumption zones, and judge the formation timing of high water consumption zones, which is of great significance for controlling the development of high water consumption zones, improving reservoir recovery, and optimizing the well network of oil field development. However, at present, a relatively complete characterization and identification method for high water consumption zones has not been formed at home and abroad, and the analysis results of existing methods are mostly qualitative, lacking a combination of quantitative and qualitative identification methods.

[0004] The present invention provides a method for identifying high water consumption zones in oil reservoirs by using streamline density. The present invention establishes a quantitative high water consumption zone determination standard; accurately characterizes the distribution law of high water consumption zones, and can also qualitatively observe the change in water content in the oil layer and the distribution law of residual oil, providing a reference basis for the efficient development of water injection oil fields. Summary of the invention

[0005] In order to establish a quantitative high water consumption zone determination standard, the present invention provides a method for identifying a high water consumption zone in an oil reservoir by using streamline density, comprising: establishing a quantitative high water consumption zone determination standard by using the streamline density variation law, dividing the oil reservoir into layers and grids, calculating the streamline density of different grids, finding the maximum and minimum streamline density of each layer and the entire oil reservoir, dividing the grids with different water consumption degrees based on the dichotomy idea, and then calculating the maximum and minimum cumulative external water displacement multiples of different grids in the second potential high water consumption zone by a fuzzy comprehensive evaluation method, and then performing interval division, finally, superimposing and calculating the streamline density and external water displacement multiple of the same grid, and comprehensively determining the high water consumption zone. The present invention establishes a quantitative high water consumption zone determination method, accurately characterizes the distribution law of the high water consumption zone, and can also qualitatively observe the change of water content in the oil layer and the distribution law of the remaining oil, providing a reference basis for the efficient development of water injection oil fields.

[0006] In order to achieve the above technical effects, the following technical solutions are adopted:

[0007] A method for identifying a high water consumption zone in an oil reservoir by using streamline density comprises the following steps:

[0008] Step S1: Use streamline numerical simulation technology to simulate the density and color change law of streamlines between oil and water wells, and use the law of streamline density change to establish a quantitative high water consumption zone determination standard:

[0009] Taking a small layer k in the reservoir as the research object, different grids are divided, and the streamline density of different grids is calculated. The streamline density values ​​of each grid are arranged in order from small to large, and the minimum value is recorded as The maximum value is recorded as After obtaining the maximum and minimum values ​​of the k-layer streamline density, the streamline density value is divided into intervals. Based on the dichotomy method, the maximum and minimum values ​​of the k-layer streamline density are equally divided into b parts, and they are classified and named as low water consumption grid, medium-low water consumption grid, medium-high water consumption grid, and high water consumption grid respectively:

[0010] Assuming that the entire reservoir has m small layers, all small layers are taken as the research object, and the minimum streamline density of the first layer is recorded as The maximum streamline density is recorded as The minimum streamline density of the second layer is recorded as The maximum streamline density is recorded as By analogy, the minimum value of the mth layer is recorded as The maximum value is recorded as Then the minimum value of the entire oil layer is min and the maximum value ρ max They are:

[0011]

[0012]

[0013] After obtaining the maximum and minimum values ​​of the streamline density of the entire reservoir, the maximum and minimum values ​​of the streamline density of the entire reservoir are divided into b parts based on the dichotomy method, and are classified and named as low water consumption grid, medium-low water consumption grid, medium-high water consumption grid, and high water consumption grid respectively;

[0014] Step S2: characterize geological parameters by a fuzzy comprehensive evaluation method to obtain a first potential high water consumption zone; characterize water saturation in the first potential high water consumption zone by an injection-production well pattern, and obtain a second potential high water consumption zone with a water saturation mutation zone as a boundary; obtain a high water consumption zone with a cumulative external water displacement multiple mutation zone as a boundary in the second potential high water consumption zone;

[0015] Different grids are divided in the second potential high water consumption zone to calculate the cumulative external water displacement multiples, and the maximum and minimum values ​​of the cumulative external water displacement multiples of different grids in the second potential high water consumption zone are obtained. Based on the dichotomy method, the maximum and minimum values ​​of the cumulative external water displacement multiples are divided into b parts for interval division;

[0016] Step S3: superimpose the streamline density and external water displacement multiple of the same grid in step S1 and step S2 to obtain a superposition value α, and divide the superposition value α into b parts based on the dichotomy idea for interval division;

[0017] Determine the superposition change rate α that the injection well passes through in a straight line. Take the mutation point of the superposition value α as the boundary block. The closed area surrounded by the boundary blocks is the high water consumption layer zone.

[0018] Furthermore, the specific method for calculating the streamline density of different grids at different layers is:

[0019] Since the total number of streamlines in each small layer is different, in order to quantitatively identify the streamline density, the overall number of streamlines in each small layer is defined as the number of streamlines N in the small layer with the most streamlines in the entire reservoir. A small layer k in the reservoir is taken as the research object, the overall number of streamlines in the small layer is recorded as N, the number of streamlines passing through different grids is recorded as a, and the streamline density is the ratio of the number of streamlines passing through the unit grid during the development period to the overall number of streamlines in the small layer, using the formula:

[0020]

[0021] Compute the streamline density for different meshes.

[0022] Furthermore, the maximum and minimum values ​​of the streamline density of the k layer are divided into b parts, the maximum and minimum values ​​of the streamline density of the entire reservoir are divided into b parts, the maximum and minimum values ​​of the cumulative external water displacement multiples are divided into b parts, and the superposition value is divided into b parts, wherein b is greater than or equal to 4.

[0023] Furthermore, when b is 4:

[0024] The maximum and minimum values ​​of the k-layer streamline density are equally divided into four parts, that is, 25%, 50%, and 75% are used as the dividing points, and they are divided into four parts and named low water consumption grid, medium-low water consumption grid, medium-high water consumption grid, and high water consumption grid respectively:

[0025]

[0026] The maximum and minimum values ​​of the streamline density of the entire reservoir are equally divided into 4 parts, that is, 25%, 50%, and 75% are used as the dividing points, and they are divided into 4 parts and named low water consumption grid, medium-low water consumption grid, medium-high water consumption grid, and high water consumption grid respectively:

[0027] {(ρ min , ρ 25％ ), (ρ 25％ , ρ 50％ ), (ρ 50％ , ρ 75％ ), (ρ 75％ , ρ max )}

[0028] The maximum and minimum values ​​of the cumulative external water displacement multiples are divided into four parts, and the cumulative external water displacement multiple F is calculated in the second potential high water consumption zone. wot Divide the interval into 4 equal parts:

[0029] {(F wotmin , F wot25％ ), (F wot25％ , F wot50％ ), (F wot50％ , F wot75％ ), (F wot75％ , F wotmax )}

[0030] Divide the superposition value α into 4 equal parts, and divide α into 4 equal intervals:

[0031] {(α min , α 25％ ), (α 25％ , α 50％ ), (a 50％ , α 75％ ), (α 75％ , α max )}.

[0032] Furthermore, the specific method for superimposing the streamline density and external water displacement multiple of the same grid in step S1 and step S2 is:

[0033] The superposition is performed according to the geometric mean formula:

[0034]

[0035] Among them, α is the superposition value, ρ is the same grid streamline density, F wot Cumulative external water displacement multiples for the same grid.

[0036] Furthermore, in step S2, characterizing geological parameters by a fuzzy comprehensive evaluation method to obtain the first potential high water consumption zone specifically includes the following steps:

[0037] 1) Obtaining geological parameters, including porosity, permeability, effective thickness, and conductivity;

[0038] 2) Use frequency statistics to determine the weight factors of various geological parameters, and obtain the weight set A = (c1, c2, ..., c n ), n is the total number of geological parameters;

[0039] 3) Obtain the first potential high water consumption zone according to the fuzzy comprehensive evaluation method, the evaluation set of the fuzzy comprehensive evaluation model is V = {v1, v2, v3, v4, v5}; v1 is an extremely low water consumption zone, v2 is a low water consumption zone, v3 is a medium water consumption zone, v4 is a high water consumption zone, and v5 is an extremely high water consumption zone; the factor set is U = (u1, u2, u i ,…,u n ),u i is the i-th geological parameter, and n is the total number of geological parameters.

[0040] Furthermore, in step S2, the water saturation is characterized by the injection-production well pattern in the first potential high water consumption zone, and the second potential high water consumption zone is obtained with the water saturation mutation zone as the boundary. The specific steps are as follows:

[0041] 1) Divide the first potential high water consumption layer into several grids and obtain the water saturation of each grid;

[0042] 2) Determine the water saturation change rate of each grid that is radiated outward from the water injection well, take the water saturation mutation point as the boundary grid, and obtain the boundary grid around the water injection well;

[0043] 3) Connect each first boundary grid, and the closed area enclosed by each boundary grid is the second potential high aquifer zone.

[0044] Furthermore, the specific method for calculating the cumulative external water displacement multiple in the second potential high water consumption layer zone in step S2 is:

[0045] Different grids are divided in the second potential high water consumption layer zone to calculate the cumulative external water displacement multiples of different grids respectively; the calculation formula of the cumulative external water displacement multiples is as follows:

[0046] V wp =V w -V wi

[0047]

[0048] Where: V wo is the amount of external water passing through per unit time, sm 3 ; V w is the amount of water passing through per unit time, sm 3 ; V wi is the amount of formation water passing through per unit time, sm 3 ; Fwot V is the cumulative displacement multiple of external water; p is the pore volume sm 3 .

[0049] Furthermore, the frequency statistics method is used to determine the weight factors of various geological parameters, and the weight set A = (c1, c2, ..., c n ) is as follows:

[0050] 1) d experts independently give weights for each geological parameter;

[0051]

[0052] Where n is the total number of geological parameters, c ij is the weight of the i-th geological parameter given by the j-th expert;

[0053] 2) Determine the maximum value c of the weight of the i-th geological parameter max and the minimum value c min ;

[0054] 3) Select a positive integer f and use the formula Calculate the group distance that divides the weights into f groups, and divide the weights into f groups from large to small;

[0055] 4) Calculate the frequency and frequency of weights falling within each group;

[0056] 5) According to the frequency and frequency distribution, select the median value of the group with the maximum frequency as the weight c of the i-th geological parameter i The weight of

[0057] 6) Repeat steps 1)-5) to obtain the weight of each geological parameter, thereby obtaining a weight set A = (c1, c2, ..., c n ).

[0058] Furthermore, the streamline numerical simulation technology can simulate the color change between oil and water wells, so as to qualitatively obtain the development law of high water consumption zone and the change law of remaining oil distribution; the formation timing of high water consumption zone can be determined according to the change trend of streamline density in a certain area of ​​the reservoir, and the greater the change of streamline density, the higher the possibility of forming high water consumption zone; because streamlines are directional, the development trend of high water consumption zone can be predicted according to the streamline direction of high water consumption grids at the same position at different times.

[0059] Beneficial Effects of the Invention

[0060] The invention discloses a method for identifying a high water consumption layer zone of an oil reservoir by using streamline density, comprising: establishing a quantitative high water consumption layer zone determination standard by using the streamline density variation law, dividing the oil reservoir into layers and grids, calculating the streamline density of different grids, finding the maximum and minimum streamline density of each layer and the entire oil reservoir, dividing the grids with different water consumption degrees based on the dichotomy idea, and then calculating the maximum and minimum cumulative external water displacement multiples of different grids in the second potential high water consumption layer zone by a fuzzy comprehensive evaluation method, and then performing interval division, and finally, superimposing and calculating the streamline density and external water displacement multiple of the same grid, and comprehensively determining the high water consumption layer zone. The invention establishes a quantitative high water consumption layer zone determination method, accurately characterizes the distribution law of the high water consumption layer zone, and can also qualitatively observe the change of water content in the oil layer and the distribution law of the remaining oil, so as to provide a reference basis for the efficient development of water injection oil fields.

[0061] Streamline numerical simulation technology can simulate the color changes between oil and water wells, thereby qualitatively obtaining the development of high water consumption zones and the changing laws of remaining oil distribution.

[0062] The formation timing of high water consumption stripes can be determined according to the change trend of streamline density in a certain area of ​​the reservoir. The greater the change of streamline density, the higher the possibility of forming high water consumption stripes.

[0063] Since streamlines are directional, the development trend of high water consumption zones can be predicted based on the streamline directions of high water consumption grids at the same location at different times.

[0064] The advantage of using the geometric mean formula to superimpose the α value is that compared with the arithmetic mean formula, the geometric mean formula is less affected by extreme values ​​and the obtained interval identification range is more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 is a flowchart of an embodiment of the present invention; DETAILED DESCRIPTION

[0066] The present invention is further described below in conjunction with the accompanying drawings, and the protection scope of the present invention is not limited to the following:

[0067] according to Figure 1 As shown, the embodiment takes b as 4, that is, the maximum and minimum values ​​of the streamline density of the k layer are divided into 4 parts, the maximum and minimum values ​​of the streamline density of the entire reservoir are divided into 4 parts, the maximum and minimum values ​​of the cumulative external water displacement multiples are divided into 4 parts, and the superposition value is divided into 4 parts for description. Other equal division methods are similar and will not be repeated here.

[0068] Step S1: Use streamline numerical simulation technology to simulate the density and color change law of streamlines between oil and water wells, and use the law of streamline density change to establish a quantitative high water consumption zone determination standard:

[0069] Taking a small layer k in the reservoir as the research object, different grids are divided, and the streamline density of different grids is calculated. The streamline density values ​​of each grid are arranged in order from small to large, and the minimum value is recorded as The maximum value is recorded as After obtaining the maximum and minimum values ​​of the k-layer streamline density, the streamline density value is divided into intervals. Based on the dichotomy method, the maximum and minimum values ​​of the k-layer streamline density are equally divided into 4 parts, that is, 25%, 50%, and 75% are used as the dividing points to divide it into 4 parts and named low water consumption grid, medium-low water consumption grid, medium-high water consumption grid, and high water consumption grid respectively:

[0070]

[0071] The specific method for calculating the streamline density of different grids in different layers is:

[0072] Since the total number of streamlines in each small layer is different, in order to quantitatively identify the streamline density, the overall number of streamlines in each small layer is defined as the number of streamlines N in the small layer with the most streamlines in the entire reservoir. A small layer k in the reservoir is taken as the research object, the overall number of streamlines in the small layer is recorded as N, the number of streamlines passing through different grids is recorded as a, and the streamline density is the ratio of the number of streamlines passing through the unit grid during the development period to the overall number of streamlines in the small layer, using the formula:

[0073]

[0074] Compute the streamline density for different meshes.

[0075] Assuming that the entire reservoir has m small layers, all small layers are taken as the research object, and the minimum streamline density of the first layer is recorded as The maximum streamline density is recorded as The minimum streamline density of the second layer is recorded as The maximum streamline density is recorded as By analogy, the minimum value of the mth layer is recorded as The maximum value is recorded as Then the minimum value of the entire oil layer is min and the maximum value ρ max They are:

[0076]

[0077]

[0078] After obtaining the maximum and minimum values ​​of the streamline density of the entire reservoir, the maximum and minimum values ​​of the streamline density of the entire reservoir are divided into 4 parts based on the dichotomy method, that is, 25%, 50%, and 75% are used as the separation points, and they are divided into 4 parts and named low water consumption grid, medium-low water consumption grid, medium-high water consumption grid, and high water consumption grid respectively:

[0079] {(ρ min , ρ 25％ ), (ρ 25％ , ρ 50％ ), (ρ 50％ , ρ 75％ ), (ρ 75％ , ρ max )};

[0080] Step S2: characterize geological parameters by a fuzzy comprehensive evaluation method to obtain a first potential high water consumption zone; characterize water saturation in the first potential high water consumption zone by an injection-production well pattern, and obtain a second potential high water consumption zone with a water saturation mutation zone as a boundary; obtain a high water consumption zone with a cumulative external water displacement multiple mutation zone as a boundary in the second potential high water consumption zone;

[0081] The method of characterizing geological parameters by a fuzzy comprehensive evaluation method to obtain the first potential high water consumption zone specifically includes the following steps:

[0082] 1) Obtaining geological parameters, including porosity, permeability, effective thickness, and conductivity;

[0083] 2) Use frequency statistics to determine the weight factors of various geological parameters, and obtain the weight set A = (c1, c2, ..., c n ), n is the total number of geological parameters;

[0084] 3) Obtain the first potential high water consumption zone according to the fuzzy comprehensive evaluation method, the evaluation set of the fuzzy comprehensive evaluation model is V = {v1, v2, v3, v4, v5}; v1 is an extremely low water consumption zone, v2 is a low water consumption zone, v3 is a medium water consumption zone, v4 is a high water consumption zone, and v5 is an extremely high water consumption zone; the factor set is U = (u1, u2, u i ,…,u n ),u i is the i-th geological parameter, and n is the total number of geological parameters.

[0085] The frequency statistics method is used to determine the weight factors of various geological parameters, and the weight set A is obtained as follows: (c1, c2, ..., c n ) is as follows:

[0086] 1) d experts independently give weights for each geological parameter;

[0087]

[0088] Where n is the total number of geological parameters, c ij is the weight of the i-th geological parameter given by the j-th expert;

[0089] 2) Determine the maximum value c of the weight of the i-th geological parameter max and the minimum value c min ;

[0090] 3) Select a positive integer f and use the formula Calculate the group distance that divides the weights into f groups, and divide the weights into f groups from large to small;

[0091] 4) Calculate the frequency and frequency of weights falling within each group;

[0092] 5) According to the frequency and frequency distribution, select the median value of the group with the maximum frequency as the weight c of the i-th geological parameter i The weight of

[0093] 6) Repeat steps 1)-5) to obtain the weight of each geological parameter, thereby obtaining a weight set A = (c1, c2, ..., c n ).

[0094] The specific steps of characterizing water saturation in the first potential high water consumption zone by injection-production well pattern and obtaining the second potential high water consumption zone with the water saturation mutation zone as the boundary are as follows:

[0095] 1) Divide the first potential high water consumption layer into several grids and obtain the water saturation of each grid;

[0096] 2) Determine the water saturation change rate of each grid that is radiated outward from the water injection well, take the water saturation mutation point as the boundary grid, and obtain the boundary grid around the water injection well;

[0097] 3) Connect each first boundary grid, and the closed area enclosed by each boundary grid is the second potential high aquifer zone.

[0098] Different grids are divided in the second potential high water consumption zone to calculate the cumulative external water displacement multiples, and the maximum and minimum values ​​of the cumulative external water displacement multiples in different grids in the second potential high water consumption zone are obtained. Based on the dichotomy method, the maximum and minimum values ​​of the cumulative external water displacement multiples are divided into 4 parts. The cumulative external water displacement multiple F in the second potential high water consumption zone is calculated. wot Divide the interval into 4 equal parts:

[0099] {(F wotmin , F wot25％ ), (F wot25％ , F wot50％ ), (F wot50％ , F wot75％ ), (F wot75％ , F wotmax )};

[0100] The specific method for calculating the cumulative external water displacement multiple in the second potential high water consumption zone is:

[0101] Different grids are divided in the second potential high water consumption layer zone to calculate the cumulative external water displacement multiples of different grids respectively; the calculation formula of the cumulative external water displacement multiples is as follows:

[0102] V wo =V w -V wi

[0103]

[0104] Where: V w o is the amount of external water passing through per unit time, sm 3 ; V w is the amount of water passing through per unit time, sm 3 ; V wi is the amount of formation water passing through per unit time, sm 3 ; F wot is the cumulative external water displacement multiple; Vp is the pore volume sm 3 .

[0105] Step S3: Superimpose the streamline density and external water displacement multiple of the same grid in step S1 and step S2 to obtain the superposition value α. Based on the idea of ​​dichotomy, the superposition value α is divided into 4 equal parts, and α is divided into 4 equal intervals:

[0106] {(α min , α 25％ ), (α 25％ , α 50％ ), (α 50％ , α 75％ ), (α 75％ , α max )};

[0107] The specific method for superimposing the streamline density and external water displacement multiple of the same grid in step S1 and step S2 is:

[0108] The superposition is performed according to the geometric mean formula:

[0109]

[0110] Among them, α is the superposition value, ρ is the same grid streamline density, F wot Cumulative external water displacement multiples for the same grid.

[0111] Determine the superposition change rate α that the injection well passes through in a straight line. Take the mutation point of the superposition value α as the boundary block. The closed area surrounded by the boundary blocks is the high water consumption layer zone.

[0112] The advantage of using the geometric mean formula to superimpose the α value is that compared with the arithmetic mean formula, the geometric mean formula is less affected by extreme values ​​and the obtained interval identification range is more accurate.

[0113] Streamline numerical simulation technology can simulate the color changes between oil and water wells, so as to qualitatively obtain the development of high water consumption zones and the changing laws of remaining oil distribution. The formation timing of high water consumption zones can be determined according to the change trend of streamline density in a certain area of ​​the reservoir. The greater the change of streamline density, the higher the possibility of forming high water consumption zones. Since streamlines are directional, the development trend of high water consumption zones can be predicted according to the streamline directions of high water consumption grids at the same position at different times.

[0114] The invention discloses a method for identifying a high water consumption layer zone of an oil reservoir by using streamline density, comprising: establishing a quantitative high water consumption layer zone determination standard by using the streamline density variation law, dividing the oil reservoir into layers and grids, calculating the streamline density of different grids, finding the maximum and minimum streamline density of each layer and the entire oil reservoir, dividing the grids with different water consumption degrees based on the dichotomy idea, and then calculating the maximum and minimum cumulative external water displacement multiples of different grids in the second potential high water consumption layer zone by a fuzzy comprehensive evaluation method, and then performing interval division, and finally, superimposing and calculating the streamline density and external water displacement multiple of the same grid, and comprehensively determining the high water consumption layer zone. The invention establishes a quantitative high water consumption layer zone determination method, accurately characterizes the distribution law of the high water consumption layer zone, and can also qualitatively observe the change of water content in the oil layer and the distribution law of the remaining oil, so as to provide a reference basis for the efficient development of water injection oil fields.

[0115] At this point, those skilled in the art recognize that, although the embodiments of the present invention have been shown and described in detail herein, many other variations or modifications that conform to the principles of the present invention can still be directly determined or derived based on the contents disclosed in the present invention without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention should be understood and recognized as covering all such other variations or modifications.

Claims

1. A method for identifying high water consumption zones in oil reservoirs using streamline density, characterized in that: The method comprises the following steps: Step S1: Use streamline numerical simulation technology to simulate the density and color change law of streamlines between oil and water wells, and use the law of streamline density change to establish a quantitative high water consumption zone determination standard: Taking a small layer k in the reservoir as the research object, different grids are divided, and the streamline density of different grids is calculated. The streamline density values ​​of each grid are arranged in order from small to large, and the minimum value is recorded as The maximum value is recorded as After obtaining the maximum and minimum values ​​of the k-layer streamline density, the streamline density value is divided into intervals. Based on the dichotomy method, the maximum and minimum values ​​of the k-layer streamline density are equally divided into b parts, and they are classified and named as low water consumption grid, medium-low water consumption grid, medium-high water consumption grid, and high water consumption grid respectively: Assuming that the entire reservoir has m small layers, all small layers are taken as the research object, and the minimum streamline density of the first layer is recorded as The maximum value of streamline density is recorded as The minimum streamline density of the second layer is recorded as The maximum value of streamline density is recorded as By analogy, the minimum value of the mth layer is recorded as The maximum value is recorded as Then the minimum value of the entire oil layer is min and the maximum value ρ max They are: After obtaining the maximum and minimum values ​​of the streamline density of the entire reservoir, the maximum and minimum values ​​of the streamline density of the entire reservoir are divided into b parts based on the dichotomy method, and are classified and named as low water consumption grid, medium-low water consumption grid, medium-high water consumption grid, and high water consumption grid respectively; Step S2: characterize geological parameters by a fuzzy comprehensive evaluation method to obtain a first potential high water consumption zone; characterize water saturation in the first potential high water consumption zone by an injection-production well pattern, and obtain a second potential high water consumption zone with a water saturation mutation zone as a boundary; obtain a high water consumption zone with a cumulative external water displacement multiple mutation zone as a boundary in the second potential high water consumption zone; Different grids are divided in the second potential high water consumption zone to calculate the cumulative external water displacement multiples, and the maximum and minimum values ​​of the cumulative external water displacement multiples of different grids in the second potential high water consumption zone are obtained. Based on the dichotomy method, the maximum and minimum values ​​of the cumulative external water displacement multiples are divided into b parts for interval division; Step S3: superimpose the streamline density and external water displacement multiple of the same grid in step S1 and step S2 to obtain a superposition value α, and divide the superposition value α into b parts based on the dichotomy idea for interval division; Determine the superposition change rate α that the injection well passes through in a straight line. Take the mutation point of the superposition value α as the boundary block. The closed area surrounded by the boundary blocks is the high water consumption layer zone.

2. A method for identifying high water consumption zones in oil reservoirs by using streamline density as claimed in claim 1, characterized in that: The specific method for calculating the streamline density of different grids in different layers is: Since the total number of streamlines in each small layer is different, in order to quantitatively identify the streamline density, the overall number of streamlines in each small layer is defined as the number of streamlines N in the small layer with the most streamlines in the entire reservoir. A small layer k in the reservoir is taken as the research object, the overall number of streamlines in the small layer is recorded as N, the number of streamlines passing through different grids is recorded as a, and the streamline density is the ratio of the number of streamlines passing through the unit grid during the development period to the overall number of streamlines in the small layer, using the formula: Compute the streamline density for different meshes.

3. The method for identifying high water consumption zones in oil reservoirs by using streamline density according to claim 1, characterized in that: The maximum and minimum values ​​of the k-layer streamline density are divided into b parts, the maximum and minimum values ​​of the entire reservoir streamline density are divided into b parts, the maximum and minimum values ​​of the cumulative external water displacement multiples are divided into b parts, and the superposition value is divided into b parts, wherein b is greater than or equal to 4.

4. The method for identifying high water consumption zones in oil reservoirs by using streamline density according to claim 1, characterized in that: When b is 4: The maximum and minimum values ​​of the k-layer streamline density are equally divided into four parts, that is, 25%, 50%, and 75% are used as the dividing points, and they are divided into four parts and named low water consumption grid, medium-low water consumption grid, medium-high water consumption grid, and high water consumption grid respectively: The maximum and minimum values ​​of the streamline density of the entire reservoir are equally divided into 4 parts, that is, 25%, 50%, and 75% are used as the dividing points, and they are divided into 4 parts and named low water consumption grid, medium-low water consumption grid, medium-high water consumption grid, and high water consumption grid respectively: {(r min ,r 25％ ),(p 25％ ,r 50％ ),(p 50％ ,r 75％ ),(p 75％ ,r max )} The maximum and minimum values ​​of the cumulative external water displacement multiples are divided into four parts, and the cumulative external water displacement multiple F is calculated in the second potential high water consumption zone. wot Divide the interval into 4 equal parts: {(F wotmin ,F wot25％ ),(F wot25％ ,F wot50％ ),(F wot50％ ,F wot75％ ),(F wot75％ ,F wotmax )} Divide the superposition value α into 4 equal parts, and divide α into 4 equal intervals: {(α min ，α 25％ ),(α 25％ ,α 50％ ),(α 50％ ,α 75％ ),(α 75％ ，α max )}。 5. The method for identifying high water consumption zones in oil reservoirs by using streamline density according to claim 1, characterized in that: The specific method for superimposing the streamline density and external water displacement multiple of the same grid in step S1 and step S2 is: The superposition is performed according to the geometric mean formula: Among them, α is the superposition value, ρ is the same grid streamline density, F wot Cumulative external water displacement multiples for the same grid.

6. The method for identifying high water consumption zones in oil reservoirs by using streamline density according to claim 1, characterized in that: In step S2, the first potential high water consumption zone is obtained by characterizing geological parameters using a fuzzy comprehensive evaluation method, which specifically includes the following steps: 1) Obtaining geological parameters, including porosity, permeability, effective thickness, and conductivity; 2) Use frequency statistics to determine the weight factors of various geological parameters, and obtain the weight set A = (c1, c2, ..., c n ), n is the total number of geological parameters; 3) The first potential high water consumption zone is obtained according to the fuzzy comprehensive evaluation method. The evaluation set of the fuzzy comprehensive evaluation model is V = {v1, v2, v3, v4, v5}; v1 is an extremely low water consumption zone, v2 is a low water consumption zone, v3 is a medium water consumption zone, v4 is a high water consumption zone, and v5 is an extremely high water consumption zone; the factor set is U = (u1, u2, u i ,…,u n ),u i is the i-th geological parameter, and n is the total number of geological parameters.

7. The method for identifying high water consumption zones in oil reservoirs by using streamline density according to claim 1, characterized in that: The step S2 characterizes the water saturation in the first potential high water consumption layer zone by the injection-production well pattern, and obtains the second potential high water consumption layer zone with the water saturation mutation zone as the boundary, and the specific steps are as follows: 1) Divide the first potential high water consumption layer into several grids and obtain the water saturation of each grid; 2) Determine the water saturation change rate of each grid that is radiated outward from the water injection well, take the water saturation mutation point as the boundary grid, and obtain the boundary grid around the water injection well; 3) Connect each first boundary grid, and the closed area enclosed by each boundary grid is the second potential high aquifer zone.

8. The method for identifying high water consumption zones in oil reservoirs by using streamline density according to claim 1, characterized in that: The specific method for calculating the cumulative external water displacement multiple in the second potential high water consumption layer zone in step S2 is: Different grids are divided in the second potential high water consumption layer zone to calculate the cumulative external water displacement multiples of different grids respectively; the calculation formula of the cumulative external water displacement multiples is as follows: V wo =V w -V wi Where: V wo is the amount of external water passing through per unit time, sm 3 ; V w is the amount of water passing through per unit time, sm 3 ; V wi is the amount of formation water passing through per unit time, sm 3 ; F wot V is the cumulative displacement multiple of external water; p is the pore volume sm 3 .

9. A method for identifying high water consumption zones in oil reservoirs by using streamline density as claimed in claim 6, characterized in that: The frequency statistics method is used to determine the weight factors of various geological parameters, and the weight set A is obtained as follows: (c1, c2, ..., c n ) is as follows: 1) d experts independently give weights for each geological parameter; Where n is the total number of geological parameters, c ij is the weight of the i-th geological parameter given by the j-th expert; 2) Determine the maximum value c of the weight of the i-th geological parameter max and the minimum value c min ; 3) Select a positive integer f and use the formula Calculate the group distance that divides the weights into f groups, and divide the weights into f groups from large to small; 4) Calculate the frequency and frequency of weights falling within each group; 5) According to the frequency and frequency distribution, select the median value of the group with the maximum frequency as the weight c of the i-th geological parameter i The weight of 6) Repeat steps 1)-5) to obtain the weight of each geological parameter, thereby obtaining a weight set A = (c1, c2, ..., c n ).

10. The method for identifying high water consumption zones in oil reservoirs by using streamline density according to claim 1, characterized in that: The streamline numerical simulation technology can simulate the color change between oil and water wells, so as to qualitatively obtain the development law of high water consumption zone and the change law of remaining oil distribution; the formation timing of high water consumption zone can be determined according to the change trend of streamline density in a certain area of ​​the reservoir, and the greater the change of streamline density, the higher the possibility of forming high water consumption zone; because streamlines are directional, the development trend of high water consumption zone can be predicted according to the streamline direction of high water consumption grids at the same position at different times.

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