CN103670369B - Method and device for judging communication condition between injection wells and production wells - Google Patents

Abstract

The invention discloses a method and a device for judging the communication condition between injection wells and production wells. The method for judging the communication condition between injection wells and production wells comprises the following steps: s1: data points of the oilfield block to be determined are optimized unreasonably; s2: according to the optimized data of S1, calculating an initial value of the injection-production interwell communication coefficient and an initial value of a time lag constant of the oil field block to be determined; s3: substituting the optimized data of S1 and the initial value of the communication coefficient between injection wells and the production well calculated in S2 into an objective function, and calculating the communication coefficient between injection wells, the time lag constant and the interference constant between production wells when the objective function value is smaller than the fitting error; s4: and (4) judging the communication condition between the injection wells and the production wells by utilizing the communication coefficient between the injection wells and the production wells, the time lag constant and the interference constant between the production wells which are calculated by the S3. The method and the device are beneficial to improving the rationality of judging the communication condition between the injection wells and the production wells of the high-water-content oil field.

Description

Method and device for judging communication condition between injection wells and production wells

Technical Field

The invention belongs to the field of oil field injection and production, and particularly relates to a method and a device for judging the communication condition between injection wells and production wells.

Background

The process of reservoir exploitation is often accompanied by the continuous reduction of reservoir pressure, and the exploitation work of the reservoir is influenced when the reservoir pressure is reduced to a certain degree. In order to reduce the pressure drop of the reservoir, the reservoir pressure is supplemented by a water flooding development method. When water injection development is implemented, a plurality of water injection wells and production wells are often required to form an injection-production well pattern. Because the geological condition of the oil reservoir is very complicated, the injected water of one water injection well has different driving degrees on different production wells, namely the water driving degrees are different. The water flooding degree has great influence on the yield of the production well, and the yield of the production well can be continuously stable or gradually increased if the water flooding degree is good; if the water flooding level is poor, the production well production will gradually decrease. The communication condition between injection and production wells is an important factor influencing the water flooding degree, so that the judgment of the communication condition between the injection and production wells is very important for the exploitation of the whole oil reservoir.

The existing method for judging the communication condition between injection wells and production wells generally adopts a capacitance resistance method.

The capacitance resistance method is characterized in that the communication condition between injection wells and production wells is represented by an injection-production inter-well communication coefficient (the injection-production inter-well communication coefficient reflects the strength of the communication condition between an injection well and a surrounding production well) and a time lag constant (the time lag constant represents the time required by injected water to reach the production well) which are calculated by establishing an objective function. The established objective function is represented by the sum of the squares of the differences between the calculated fluid production and the actual fluid production for the production well. The objective function considers the medium between an injection well, a production well and an injection-production well in the oil deposit as a complete system. In the system, the injected water is influenced by the communication condition between the injection wells and the production wells when the injected water is spread between the injection wells and the production wells, and the influence is directly reflected in the actual liquid production amount of the production wells.

The capacitance resistance method takes each production well as an independent individual, the calculated liquid production capacity of the production well in the established objective function at a certain time step is represented as the influence of the calculated liquid production capacity of the previous time step, the communication coefficient among injection and production wells and the time lag constant, and the objective function is expressed by a function formula formed by the initial calculated liquid production capacity of the production well, the communication coefficient among injection and production wells and the time lag constant through iterative calculation of the calculated liquid production capacity of the previous time step. The initial calculated fluid production is the same as the initial actual fluid production of the production well. By substituting the production data of the oil field, the communication coefficient and the time lag constant between the injection wells and the production wells can be calculated by a capacitance resistance method, and the communication condition between the injection wells and the production wells can be reflected by the communication coefficient and the time lag constant between the injection wells and the production wells.

In the prior art, the objective function established by the capacitance-resistance method does not take the interferences of other production wells into consideration. The high water content oil field is generally developed by adopting a dense well pattern, the interference among production wells has large influence on the communication condition among injection and production wells and cannot be ignored, so that the capacitance resistance method has certain irrationality in judging the communication condition among the injection and production wells of the high water content oil field.

Disclosure of Invention

The invention aims to provide a method for judging the communication condition between injection wells and production wells, so as to judge the communication condition between injection wells and production wells of a high water-cut oil field more reasonably.

The invention provides a method for judging the communication condition between injection wells and production wells, which is characterized by comprising the following steps of:

s1: data points for which data optimization of the oilfield block to be determined is not reasonable, the data of the oilfield block to be determined comprising: the number of injection wells, the number of production wells, the water injection amount of each injection well in each time step, the liquid production amount of each production well in each time step, the average permeability among injection and production wells and the injection and production well spacing;

s2: according to the optimized data of S1, calculating an initial value of the injection-production interwell communication coefficient and an initial value of a time lag constant of the oil field block to be determined;

s3: substituting the optimized data of S1 and the initial value of the communication coefficient between injection wells and the production wells and the initial value of the time lag constant calculated in S2 into a target function, and calculating the communication coefficient between injection wells, the time lag constant and the interference constant between production wells when the value of the target function is smaller than the fitting error; the objective function is a function for calculating the minimum value of the superposition value of the sum of squares of the difference values of the calculated liquid production rate and the actual liquid production rate of each production well in the oil field block to be determined in all time steps;

s4: judging the strength of the communication condition between the injection wells and the production wells in the oil field block to be determined by utilizing the communication coefficient between the injection wells and the production wells calculated in the S3;

judging the shortest time for the injected water in the oil field block to reach each production well to be determined by utilizing the time lag constant calculated in the S3;

and judging that each production well in the oil field block to be determined is influenced by the interference of other production wells by using the interference constant among the production wells calculated by the S3.

The method for judging the communication condition between the injection wells and the production wells further adopts the following scheme:

the data of the oilfield block to be determined in S1 further includes: the included angle between the connecting line between the injection wells and the source direction and the average permeability between the injection wells and the production wells in the X, Y direction;

the step S4 is implemented by the following steps:

a. judging the initial value of the communication coefficient between the injection wells and the production wells and the initial value of the time lag constant calculated in the S2 through constraint conditions, and rejecting unreasonable judging data; the constraint conditions comprise an injection-production inter-well communication coefficient constraint condition, a time lag constant constraint condition and a production inter-well interference constant constraint condition and are used for constraining an injection-production inter-well communication coefficient, a time lag constant and a production inter-well interference constant;

b. substituting the optimized data of S1 and the initial value of the communication coefficient between injection wells and the initial value of the time lag constant after the judgment of a into an objective function, and calculating the communication coefficient between injection wells, the time lag constant and the interference constant between production wells when the value of the objective function is smaller than the preset value;

c. and (c) judging the communication coefficient among the injection wells and the production wells obtained by calculation in the step b through the constraint condition of the communication coefficient among the injection wells and the production wells, judging the time lag constant obtained by calculation in the step b through the constraint condition of the time lag constant, judging the interference constant among the production wells obtained by calculation in the step b through the constraint condition of the interference constant among the production wells, eliminating unreasonable judging data, and obtaining the communication coefficient among the injection wells, the time lag constant and the interference constant among the production wells which are finally used for judging the communication condition among the injection wells and the production wells.

The data points in S1 for which optimization is not reasonable include:

setting the communication coefficient and the time lag constant between injection wells and production wells of the invalid well to be 0;

and setting the communication coefficient between the injection wells and the production wells of the injection-production conversion wells to be 0.

The step of calculating the initial value of the communication coefficient between the injection wells and the production wells of the oil field block to be determined in the step of S2 includes:

calculating to obtain an initial value of the communication coefficient between the injection wells and the production wells by using the following formula:

$f_{ij}=\frac{\stackrel{\‾}{k_{ij}}/L_{ij}}{{\Σ}_{j=1}^{N_{pro}}\stackrel{\‾}{k_{ij}}/L_{ij}}$

wherein f is_ijRepresenting the communication coefficient between the injection well of the ith hole and the production well of the jth hole;the average permeability between the injection well of the ith and the production well of the jth is expressed by 10^-3Square micron; l is_ijThe well spacing of the ith injection well and the jth production well is expressed in meters; n is a radical of_proRepresenting the number of production wells in ports; wherein N is_pro、L_ijIs a known value.

The initial value of the time lag constant is the average time lag constant of the oilfield block to be determined;

the calculation step of the average time lag constant of the oilfield block to be determined comprises the following steps:

substituting the optimized data of S1 into an average time lag constant formula and calculating the average time lag constant when the formula value of the average time lag constant is smaller than a preset value;

the average time lag constant is expressed as:

$\min f\left(x\right)=\underset{k=1}{\overset{n}{\Σ}}{\[q\left(k\right)-q\left(0\right)e^{-\left(\frac{k}{\mathrm{\τ}}\right)}+\underset{k=1}{\overset{n}{\Σ}}\[(e_w+fI(k\left)\right)e^{-\frac{n-k}{\mathrm{\τ}}}(1-e^{-\frac{1}{\mathrm{\τ}}})\]\]}^2$

wherein n represents the total calculation time step in months; i (k) represents the water injection quantity of the block at the k time step, and the unit is cubic meter per day; q (k) represents the oil production of the block at the kth time step in cubic meters per day; q (0) represents the overall initial production of the block in cubic meters per day; f represents the block overall connectivity coefficient; τ represents the mean time lag constant in days; e.g. of the type_wRepresents external energy replenishment in joules; wherein I (k), q (k) are known amounts.

The fitting error is 0.1.

The objective function in S3 is:

$\min f\left(x\right)=\underset{k=1}{\overset{n}{\Σ}}\underset{j=1}{\overset{N_{pro}}{\Σ}}{\{q_j\left(k\right)-{\hat{q}}_j\left(0\right)e^{-\left(\frac{k\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)}-\underset{p=1}{\overset{k}{\Σ}}\{e^{-\left(\frac{(k-p)\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)}(1-e^{\frac{\mathrm{\Δ}t}{{\mathrm{\τ}}_j}})\[\underset{i=1}{\overset{N_i}{\Σ}}\left(f_{ij}{I}_i\right(p\left)\right)\]\}+\underset{p=1}{\overset{k}{\Σ}}{\mathrm{\α}}_j\[e^{-\frac{(k-p)\mathrm{\Δ}t}{{\mathrm{\τ}}_j}}(1-e^{\frac{\mathrm{\Δ}t}{{\mathrm{\τ}}_j}})\]\}}^2$

wherein q is_j(k) Representing the actual liquid production amount of the jth production well in k time step, wherein the unit is cubic meter per day;representing the initial yield of the jth production well in cubic meters per day; Δ t represents a time step in months; f. of_ijRepresenting the communication coefficient between the injection well of the ith hole and the production well of the jth hole α_jRepresenting the interference constant of other production forming wells to the jth production well; i is_i(p) represents the water injection quantity of the injection well at the ith hole in p time steps, and the unit is cubic meter per day; tau is_jRepresents the time lag constant for the jth production well in days; n is a radical of_iIndicating the number of injection wells in units of openings; n is a radical of_proRepresenting the number of production wells in ports; n represents the total calculation time step in months; wherein q is_j(k)、Δt、I_i(p)、N_i、N_proAnd n is a known amount.

The constraint conditions in the judgment of the initial value of the communication coefficient between the injection wells and the production wells and the initial value of the time lag constant calculated in the step S2 through the constraint conditions are as follows:

$s.t\left\{\begin{array}{c}\begin{array}{cc}0\≤\underset{i=1}{\overset{N_i}{\Σ}}{a}_{ij}{f}_{ij}\≤1,& j=1,2,...,N_{pro}\end{array}\\ 0.145\mathrm{\Δ}t\≤{\mathrm{\τ}}_j\≤1000\mathrm{\Δ}t\\ {\mathrm{\α}}_j\≥0\end{array}\right.$

wherein,is a constraint condition of communication coefficient between injection wells and production wells, a_ijIn order to influence the coefficients of the effects, $a_{ij}=\left\{\begin{array}{cc}0& d_{ij}>r_{ij}\\ 1& d_{ij}\≤r_{ij}\end{array}\right.;$ said r_ijBy passing $r_{ij}={\left(\frac{{\cos }^2{\mathrm{\θ}}_{ij}}{{a_{1ij}}^2}+\frac{{\sin }^2{\mathrm{\θ}}_{ij}}{{b_{1ij}}^2}\right)}^{-\frac{1}{2}}+{\left(\frac{{\cos }^2{\mathrm{\θ}}_{ij}}{{a_{2ij}}^2}+\frac{{\sin }^2{\mathrm{\θ}}_{ij}}{{b_{2ij}}^2}\right)}^{-\frac{1}{2}},$ $\frac{a_{1ij}}{b_{1ij}}=\frac{a_{2ij}}{b_{2ij}}=\sqrt{\frac{k_{xij}}{k_{yij}}}$ Calculating to obtain;

0.145Δt≤τ_jtime lag is not less than 1000 delta tA post-constant constraint condition;

α_jthe constraint condition of the interference constant between production wells is more than or equal to 0;

wherein d is_ijThe distance between the ith injection well and the jth production well is expressed in meters; r is_ijThe limit influence distance between the ith injection well and the jth production well is expressed in meters; k is a radical of_xijAnd k_yijThe average permeability of the ith injection well and the jth production well in the direction of X, Y is 10-3 square microns; a is_1ij、a_2ijRespectively representing the major semi-axes of ellipses formed by taking the injection well as the production well as the center of the well pair formed by the ith injection well and the jth production well, and the major semi-axes are meters; b_1ij、b_2ijRespectively representing the minor semi-axes of ellipses formed by taking the injection well as the production well as the center of the well pair formed by the ith injection well and the jth production well, and the unit is meter; theta_ijThe included angle between the direction of the source and the connecting line of the ith injection well and the jth production well is expressed in degrees; Δ t represents a time step in months; f. of_ijRepresenting the communication coefficient between the injection well of the ith hole and the production well of the jth hole α_jRepresenting the interference constant of other production forming wells to the jth production well; tau is_jRepresents the time lag constant for the jth production well in days; n is a radical of_proRepresenting the total number of producing wells in units of ports; wherein, b_1ij、b_2ijSimulating one half of the comprehensively determined reasonable well spacing by adopting an oil reservoir engineering numerical value; theta_ijAnd Δ t is a known quantity.

The invention also provides a device for judging the communication condition between injection wells and production wells, which is characterized by comprising

The data preprocessing module is used for optimizing unreasonable data points of the oilfield block to be determined, and the data of the oilfield block to be determined comprises: the number of injection wells, the number of production wells, the water injection amount of each injection well in each time step, the liquid production amount of each production well in each time step, the average permeability among injection and production wells and the injection and production well spacing;

the initial value calculation module is used for calculating an initial value of the communication coefficient between the injection wells and the production wells of the oil field block to be determined and an initial value of a time lag constant according to the data optimized by the data preprocessing module;

the result calculation module is used for substituting the data optimized by the data preprocessing module and the initial value of the communication coefficient between injection wells and the initial value of the time lag constant calculated by the initial value calculation module into an objective function, and calculating the communication coefficient between injection wells, the time lag constant and the interference constant between production wells when the value of the objective function is smaller than the fitting error; the objective function is a function for calculating the minimum value of the superposition value of the sum of squares of the difference values of the calculated liquid production rate and the actual liquid production rate of each production well in the oil field block to be determined in all time steps;

and the communication condition judging module is used for judging the strength of the communication condition between the injection wells and the production wells in the oil field block to be determined by utilizing the communication coefficient between the injection wells and the production wells calculated by the result calculating module, judging the shortest time for the injected water to reach each production well by utilizing the time lag constant calculated by the result calculating module, and judging the interference influence of other production wells on each production well by utilizing the interference constant between the production wells calculated by the result calculating module.

The device for judging the communication condition between the injection and production wells further adopts the following scheme:

the data of the oilfield block to be determined in the data preprocessing module further comprises an included angle between a connecting line between injection wells and a source direction and an average permeability between the injection wells and the production wells in the X, Y direction;

the result calculation module further comprises the following modules:

the constraint module is used for judging the initial value of the communication coefficient between the injection wells and the production wells and the initial value of the time lag constant calculated in the introduced initial value calculation module through constraint conditions and rejecting unreasonable judgment data; the constraint conditions comprise an injection-production inter-well communication coefficient constraint condition, a time lag constant constraint condition and a production inter-well interference constant constraint condition and are used for constraining an injection-production inter-well communication coefficient, a time lag constant and a production inter-well interference constant;

a calculation submodule for substituting the data optimized by the data preprocessing module and the initial value of the communication coefficient between injection wells and the production well after the judgment of the constraint module and the initial value of the time lag constant into a target function, and calculating the communication coefficient between injection wells, the time lag constant and the interference constant between production wells when the value of the target function is smaller than the fitting error;

and the judging module is used for judging the communication coefficient among the injection wells, the time lag constant and the interference constant among the production wells which are calculated in the calculating sub-module through the constraint condition, eliminating unreasonable judging data and obtaining the communication coefficient among the injection wells, the time lag constant and the interference constant among the production wells which are finally used for judging the communication condition among the injection wells.

The invention has the beneficial effects that:

1. the method considers the influence of the production well-to-well interference on the communication condition between the injection wells and the production wells, and finally expresses the communication condition between the injection wells and the production wells through the communication coefficient between the injection wells and the production well, the time lag constant and the interference constant between the production wells, so that the rationality of judging the communication condition between the injection wells and the production wells of the high-water-content oil field is enhanced.

2. According to the method, constraint conditions are introduced, the calculated communication coefficient between injection wells and production wells, the time lag constant and the interference constant between production wells are judged, unreasonable judgment data are eliminated, the judgment data are made to be more in line with geological understanding of an oil field block to be determined, the rationality of a target function is further improved, and finally the communication condition between injection wells and production wells of the high-water-content oil field can be clearly expressed through the optimal solution of the calculated target function so as to guide the fine injection and production of the oil field.

Drawings

FIG. 1 is a schematic view of a one-injection-one-mining limit influence distance;

FIG. 2 is a flowchart of a method for determining a communication status between injection wells and production wells according to a first embodiment of the present invention;

FIG. 3 is a flowchart of step S4 of a method for determining the communication status between injection wells and production wells according to a second embodiment of the present invention;

FIG. 4 is a schematic view of a first embodiment of a communication status determination device for injection wells and production wells according to the present invention;

FIG. 5 is a schematic diagram of a result calculation module according to a second embodiment of the apparatus for determining the communication status between injection wells and production wells of the present invention;

FIG. 6 is a diagram of the distribution of the initial injection-production inter-well communication coefficients;

FIG. 7 is a distribution diagram of the communication coefficient between injection wells and production wells.

Detailed Description

In order to make those skilled in the art better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 2, a first embodiment of the method for determining the communication status between injection wells and production wells in the present invention includes the following steps:

s1: data points for which data optimization of the oilfield block to be determined is not reasonable, the data of the oilfield block to be determined comprising: the number of injection wells, the number of production wells, the water injection amount of each injection well in each time step, the liquid production amount of each production well in each time step, the average permeability among injection and production wells and the injection and production well spacing;

the data points for which the S1 optimization is not reasonable include:

setting the communication coefficient and the time lag constant between injection wells and production wells of the invalid well to be 0; the invalid well is a production stopping well, and the production data is less than the average single well production data of the block;

setting the communication coefficient of the injection-production conversion well to be 0;

s2: according to the optimized data of S1, calculating an initial value of the injection-production interwell communication coefficient and an initial value of a time lag constant of the oil field block to be determined;

calculating to obtain an initial value of the communication coefficient between the injection wells and the production wells by using the following formula: :

$f_{ij}=\frac{\stackrel{\‾}{k_{ij}}/L_{ij}}{{\Σ}_{j=1}^{N_{pro}}\stackrel{\‾}{k_{ij}}/L_{ij}}$

wherein f is_ijRepresenting the communication coefficient between the injection well of the ith hole and the production well of the jth hole;the average permeability between the injection well of the ith and the production well of the jth is expressed by 10^-3Square micron; l is_ijThe well spacing of the ith injection well and the jth production well is expressed in meters; n is a radical of_proRepresenting the number of production wells in ports; wherein,L_ijare known;

the initial value of the time lag constant adopts the average time lag constant of the oilfield block to be determined;

the calculation step of the average time lag constant of the oilfield block to be determined comprises the following steps:

substituting the optimized data of S1 into an average time lag constant formula and calculating the average time lag constant when the formula value of the average time lag constant is smaller than a preset value;

the average time lag constant is expressed as:

$\min f\left(x\right)=\underset{k=1}{\overset{n}{\Σ}}{\[q\left(k\right)-q\left(0\right)e^{-\left(\frac{k}{\mathrm{\τ}}\right)}+\underset{k=1}{\overset{n}{\Σ}}\[(e_w+fI(k\left)\right)e^{-\frac{n-k}{\mathrm{\τ}}}(1-e^{-\frac{1}{\mathrm{\τ}}})\]\]}^2$

wherein n represents the total calculation time step in months; i (k) denotes the block inThe water injection amount of the kth time step is in the unit of cubic meter per day; q (k) represents the oil production of the block at the kth time step in cubic meters per day; q (0) represents the overall initial production of the block in cubic meters per day; f represents the block overall connectivity coefficient; τ represents the mean time lag constant in days; e.g. of the type_wRepresents external energy replenishment in joules; wherein I (k), q (k) are known amounts

S3: substituting the optimized data of S1 and the initial value of the communication coefficient between injection wells and the production wells and the initial value of the time lag constant calculated in S2 into a target function, and calculating the communication coefficient between injection wells, the time lag constant and the interference constant between production wells when the value of the target function is smaller than the fitting error; the objective function is a function for calculating the minimum value of the superposition value of the sum of squares of the difference values of the calculated liquid production rate and the actual liquid production rate of each production well in the oil field block to be determined in all time steps;

the objective function is:

$\min f\left(x\right)=\underset{k=1}{\overset{n}{\Σ}}\underset{j=1}{\overset{N_{pro}}{\Σ}}\{q_j\left(k\right)-{\hat{q}}_j\left(0\right)e^{-\left(\frac{k\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)}-\underset{p=1}{\overset{k}{\Σ}}\{e^{-\left(\frac{(k-p)\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)}(1-e^{\frac{\mathrm{\Δ}t}{{\mathrm{\τ}}_j}})\[\underset{i=1}{\overset{N_i}{\Σ}}\left(f_{ij}{I}_i\right(p\left)\right)\]\}+\underset{p=1}{\overset{k}{\Σ}}{\mathrm{\α}}_j\[e^{-\frac{(k-p)\mathrm{\Δ}t}{{\mathrm{\τ}}_j}}(1-e^{\frac{\mathrm{\Δ}t}{{\mathrm{\τ}}_j}})\]\}$

wherein q is_j(k) Represents the actual fluid production at k time step in cubic meters per day;representing the initial production of the production well in cubic meters per day; Δ t represents the time step, month; f. of_ijRepresenting the communication coefficient between the injection well of the ith hole and the production well of the jth hole α_jRepresenting the interference constant of other production forming wells to the jth production well; i is_i(p) represents the water injection quantity of the injection well at the ith hole in p time steps, and the unit is cubic meter per day; tau is_jIndicating time lag of jth producing wellNumber in days; n is a radical of_iIndicating the number of injection wells in units of openings; n is a radical of_proRepresenting the number of production wells in ports; n represents the total calculation time step in months; wherein q is_j(k)、Δt、I_i(p)、N_i、N_proAnd n is a known amount.

S4: judging the strength of the communication condition between the injection wells and the production wells in the oil field block to be determined by utilizing the communication coefficient between the injection wells and the production wells calculated in the S3;

judging the shortest time for the injected water in the oil field block to reach each production well to be determined by utilizing the time lag constant calculated in the S3;

and judging that each production well in the oil field block to be determined is influenced by the interference of other production wells by using the interference constant among the production wells calculated by the S3.

In the embodiment, the influence of the interference between the production wells on the communication condition between the injection wells and the production wells is considered, the interference constant between the production wells is introduced into the establishment of the objective function, and the communication condition between the injection wells and the production wells is judged by combining the communication coefficient between the injection wells and the production wells, the time lag constant and the interference constant between the production wells, so that the rationality of judging the communication condition between the injection wells and the production wells of the high-water-content oil field is enhanced, and the production work of the oil field is guided more favorably.

Steps S2 and S4 in the second embodiment of the method for determining the communication status between injection wells and production wells according to the present invention are the same as those in the first embodiment.

Step S1 in the second embodiment of the present invention is: data points for which data optimization of the oilfield block to be determined is not reasonable, the data of the oilfield block to be determined comprising: the number of injection wells, the number of production wells, the water injection amount of each injection well at each time step, the liquid production amount of each production well at each time step, the average permeability among injection and production wells, the injection and production well spacing, the included angle between the connecting line among the injection and production wells and the material source direction and the average permeability among the injection and production wells in the X, Y direction;

fig. 3 shows the specific steps included in S3 in the second embodiment. As shown in fig. 3, the S3 is implemented by the following three steps:

a. judging the initial value of the communication coefficient between the injection wells and the production wells and the initial value of the time lag constant calculated in the S2 through constraint conditions, and rejecting unreasonable judging data; the constraint conditions comprise an injection-production inter-well communication coefficient constraint condition, a time lag constant constraint condition and a production inter-well interference constant constraint condition and are used for constraining an injection-production inter-well communication coefficient, a time lag constant and a production inter-well interference constant;

the constraint conditions in the judgment of the initial value of the communication coefficient between the injection wells and the production wells and the initial value of the time lag constant calculated in the step S2 through the constraint conditions are as follows:

$s.t\left\{\begin{array}{c}\begin{array}{cc}0\≤\underset{i=1}{\overset{N_i}{\Σ}}{a}_{ij}{f}_{ij}\≤1,& j=1,2,...,N_{pro}\end{array}\\ 0.145\mathrm{\Δ}t\≤{\mathrm{\τ}}_j\≤1000\mathrm{\Δ}t\\ {\mathrm{\α}}_j\≥0\end{array}\right.$

wherein,is a constraint condition of communication coefficient between injection wells and production wells, a_ijIn order to influence the coefficients of the effects, $a_{ij}=\left\{\begin{array}{cc}0& d_{ij}>r_{ij}\\ 1& d_{ij}\≤r_{ij}\end{array}\right.;$ r_ijby passing $r_{ij}={\left(\frac{{\cos }^2{\mathrm{\θ}}_{ij}}{{a_{1ij}}^2}+\frac{{\sin }^2{\mathrm{\θ}}_{ij}}{{b_{1ij}}^2}\right)}^{-\frac{1}{2}}+{\left(\frac{{\cos }^2{\mathrm{\θ}}_{ij}}{{a_{2ij}}^2}+\frac{{\sin }^2{\mathrm{\θ}}_{ij}}{{b_{2ij}}^2}\right)}^{-\frac{1}{2}},\frac{a_{1ij}}{b_{1ij}}=\frac{a_{2ij}}{b_{2ij}}=\sqrt{\frac{k_{xij}}{k_{yij}}}$ Calculating to obtain;

0.145Δt≤τ_jthe time lag constant constraint condition is not more than 1000 delta t;

α_jthe constraint condition of the interference constant between production wells is more than or equal to 0;

wherein d is_ijThe distance between the ith injection well and the jth production well is expressed in meters; r is_ijThe limit influence distance between the ith injection well and the jth production well is expressed in meters; k is a radical of_xijAnd k_yijThe average permeability of the ith injection well and the jth production well in the direction of X, Y is 10-3 square microns; a is_1ij、a_2ijRespectively representing the major semi-axes of ellipses formed by taking the injection well as the production well as the center of the well pair formed by the ith injection well and the jth production well, and the major semi-axes are meters; b_1ij、b_2ijRespectively representing the minor semi-axes of ellipses formed by taking the injection well as the production well as the center of the well pair formed by the ith injection well and the jth production well, and the unit is meter; theta_ijThe included angle between the direction of the source and the connecting line of the ith injection well and the jth production well is expressed in degrees; Δ t represents a time step in months; f. of_ijIndicating the i-th injection well and the j-th productionWell connectivity factor α_jRepresenting the interference constant of other production forming wells to the jth production well; tau is_jRepresents the time lag constant for the jth production well in days; n is a radical of_proRepresenting the total number of producing wells in units of ports; wherein, b_1ij、b_2ijSimulating one half of the comprehensively determined reasonable well spacing by adopting an oil reservoir engineering numerical value; theta_ijΔ t is a known quantity;

b. substituting the optimized data of S1 and the initial value of the communication coefficient between injection wells and the initial value of the time lag constant after the judgment of a into a target function, and calculating the communication coefficient between injection wells, the time lag constant and the interference constant between production wells when the value of the target function is smaller than the fitting error;

the objective function is:

$\min f\left(x\right)=\underset{k=1}{\overset{n}{\Σ}}\underset{j=1}{\overset{N_{pro}}{\Σ}}\{q_j\left(k\right)-{\hat{q}}_j\left(0\right)e^{-\left(\frac{k\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)}-\underset{p=1}{\overset{k}{\Σ}}\{e^{-\left(\frac{(k-p)\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)}(1-e^{\frac{\mathrm{\Δ}t}{{\mathrm{\τ}}_j}})\[\underset{i=1}{\overset{N_i}{\Σ}}\left(f_{ij}{I}_i\right(p\left)\right)\]\}+\underset{p=1}{\overset{k}{\Σ}}{\mathrm{\α}}_j\[e^{-\frac{(k-p)\mathrm{\Δ}t}{{\mathrm{\τ}}_j}}(1-e^{\frac{\mathrm{\Δ}t}{{\mathrm{\τ}}_j}})\]\}$

wherein q is_j(k) Represents the actual fluid production at k time step in cubic meters per day;representing the initial production of the production well in cubic meters per day; Δ t represents the time step, month; f. of_ijRepresenting the communication coefficient between the injection well of the ith hole and the production well of the jth hole α_jRepresenting the interference constant of other production forming wells to the jth production well; i is_i(p) represents the water injection quantity of the injection well at the ith hole in p time steps, and the unit is cubic meter per day; tau is_jRepresents the time lag constant for the jth production well in days; n is a radical of_iIndicating the number of injection wells in units of openings; n is a radical of_proRepresenting the number of production wells in ports; n represents the total calculation time step in months; it is composed ofIn (q)_j(k)、Δt、I_i(p)、N_i、N_proAnd n is a known amount.

And the fitting error adopts a communication coefficient among injection and production wells, a time lag constant and an interference constant among production wells as an optimal solution of an objective function when min f (x) is less than or equal to 0.1.

And when the calculated value of the objective function is smaller than the fitting error, the injection-production inter-well communication coefficient, the time lag constant and the production inter-well interference constant adopt a sequential quadratic programming method.

c. And c, judging the communication coefficient among the injection wells, the time lag constant and the interference constant among the production wells obtained by calculation in the step b through the constraint condition, eliminating unreasonable judgment data, and obtaining the communication coefficient among the injection wells, the time lag constant and the interference constant among the production wells which are finally used for judging the communication condition among the injection wells.

In the second embodiment of the invention, the influence of the interference between the production wells on the communication condition between the injection wells is considered, the interference constant between the production wells is introduced into the establishment of the objective function, and the communication condition between the injection wells and the production wells is judged by combining the communication coefficient between the injection wells and the production wells, the time lag constant and the interference constant between the production wells, so that the rationality for judging the communication condition between the injection wells and the production wells of the high-water-content oil field is greatly enhanced, and the production work of the high-water-content oil field is guided more favorably.

Considering that the injection-production communication relationship is greatly influenced by geological factors, and the injection-production communication coefficient, the time lag constant and the production inter-well interference constant are consistent with geological knowledge, for example, a relatively large communication coefficient should not exist between injection-production wells with relatively long distances, the production inter-well interference constant should not be a negative value and the like, the second embodiment of the invention introduces a constraint condition into the established objective function, discriminates the calculated injection-production inter-well communication coefficient, the time lag constant and the production inter-well interference constant, rejects unreasonable discrimination data, further improves the rationality of the calculated discrimination data, finally achieves the purpose of secondarily improving the rationality of discrimination of the injection-production inter-well communication condition of the high water-cut oil field, and is more favorable for guiding the fine injection-production of the high water-cut oil field.

The second embodiment of the method for determining the communication status between injection wells and production wells according to the present invention is further described below by taking the application of the present invention to a certain block of a high water content oil field as an example.

At present, a certain block of a certain high-water-cut oil field is developed for 20 years, the water content reaches more than 80%, after the injection and production well pattern of the oil field is adjusted for many times, the water drive control degree (only 55%) and the water drive use degree (20% -35%) are still low, the flow direction of injected water is unclear, the injection and production relation is incomplete, fine water injection regulation and control are urgently needed to be implemented, and the communication condition between injection and production wells is judged to be the premise of implementing the fine water injection regulation and control.

The total number of the wells in a certain block of the high water-cut oil field is 28, wherein: 17 production wells, 5 injection wells and 6 transfer wells, the production starting time is 1 month in 1992, the data acquisition cutoff calculation time is 3 months in 2012, and the time step is 1 month. And calculating and counting the water injection amount of each injection well, the liquid production amount of each production well, the included angle between the material source direction (the direction of sand body deposition in the oil reservoir) and the connecting line between the injection and production wells, the distance between the injection and production wells, the average permeability in the X, Y direction between the injection and production wells, the average permeability between the injection and production wells and the like according to the production data and the geological static data of each well.

Aiming at the communication condition among injection and production wells of a certain block of the high water-cut oil field, the invention comprises the following steps:

s1: data points of the oilfield block to be determined are optimized unreasonably;

before judging the communication condition between injection wells and production wells, firstly preprocessing statistical data and the like, optimizing unreasonable data points and improving the fitting effect between the actual liquid production amount and the calculated liquid production amount.

Optimizing unreasonable data points includes:

setting the communication coefficient and the time lag constant between injection wells and production wells of the invalid well to be 0;

setting the communication coefficient of the injection-production conversion well to be 0;

and obtaining the required data through the steps. Due to the large amount of data required, only a part of them, i.e., the data shown in tables 1 to 3, will be listed below. The statistical data are as follows:

table 1 injection well parameter data table

TABLE 2 production well parameter data sheet

TABLE 3 parameter data sheet between injection wells and production wells

S2: according to the optimized data of S1, calculating an initial value of the injection-production interwell communication coefficient and an initial value of a time lag constant of the oil field block to be determined;

firstly, calculating the communication coefficient f between injection wells and production wells_ijIs started. According to the equilibrium state multivariable linear regression model, assuming that the flow reaches a steady state in the acquired time step, and obtaining the communication coefficient between the injection well at the ith port and the production well at the jth port as follows:

$f_{ij}=\frac{T_{ij}(p_{wfi}-p_{wfj})}{\underset{j=1}{\overset{N_{pro}}{\Σ}}{T}_{ij}(p_{wfi}-p_{wfj})}---\left(1\right)$

wherein, T_ijThe conductivity coefficient between the injection well of the ith hole and the production well of the jth hole is expressed by 10^-3Square micron meter/(millipascal second); p is a radical of_wfi、p_wfjThe bottom hole flow pressure of the i th injection well and the j th production well is respectively expressed in millipascal.

And (3) obtaining the conductivity coefficient between the injection well of the ith opening and the production well of the jth opening according to a steady-state linear flow equation:

$T_{ij}=\frac{{\stackrel{\‾}{k}}_{ij}{A}_{ij}}{{\mathrm{\μL}}_{ij}}---\left(2\right)$

wherein,the average permeability between the injection well of the ith and the production well of the jth is expressed by 10^-3Square micron; a. the_ijRepresents the cross-sectional area of flow in square meters; l is_ijThe well spacing of the ith injection well and the jth production well is expressed in meters.

Substituting the formula (2) into the formula (1), assuming that the bottom flowing pressure of the production well is the same, and assuming that the flowing sectional area of each injection well to the surrounding production well is the same, obtaining a communication coefficient initial value calculation formula:

$f_{ij}=\frac{{\stackrel{\‾}{k}}_{ij}/L_{ij}}{\underset{j=1}{\overset{N_{pro}}{\Σ}}{\stackrel{\‾}{k}}_{ij}/L_{ij}}---\left(3\right)$

it can be seen from the formula (3) that the initial value of the communication coefficient can be obtained by substituting the average permeability between injection wells and the distance between injection wells and production wells into the formula (3).

The initial value of the time lag constant adopts the average time lag constant of the oilfield block to be determined.

The average time lag constant of the oilfield block to be determined is obtained by substituting the optimized data of S1 into an average time lag constant formula and calculating the average time lag constant when the value of the average time lag constant formula is smaller than a preset value;

the average time lag constant is expressed as:

$\min f\left(x\right)=\underset{k=1}{\overset{n}{\Σ}}{\[q\left(k\right)-q\left(0\right)e^{-\left(\frac{k}{\mathrm{\τ}}\right)}+\underset{k=1}{\overset{n}{\Σ}}\[(e_w+fI(k\left)\right)e^{-\frac{n-k}{\mathrm{\τ}}}(1-e^{-\frac{1}{\mathrm{\τ}}})\]\]}^2---\left(4\right)$

wherein n represents the total calculation time step in months; i (k) represents the water injection quantity of the block at the k time step, and the unit is cubic meter per day; q (k) represents the oil production of the block at the kth time step in cubic meters per day; q (0) represents the overall initial production of the block in cubic meters per day; f represents the block overall connectivity coefficient; τ represents the mean time lag constant in days; e.g. of the type_wRepresents external energy replenishment in joules; wherein I (k), q (k) are known amounts.

And (4) substituting the optimized data of S1 into the formula (4) to calculate the average time lag constant tau of the oilfield block to be determined to be 322 days by a sequential quadratic programming method.

S3: substituting the optimized data of S1 and the initial value of the communication coefficient between injection wells and the production wells and the initial value of the time lag constant calculated in S2 into a target function, and calculating the communication coefficient between injection wells, the time lag constant and the interference constant between production wells when the value of the target function is smaller than the fitting error; the objective function is a function for calculating the minimum value of the superposition value of the sum of squares of the difference values of the calculated liquid production rate and the actual liquid production rate of each production well in the oil field block to be determined in all time steps;

the S3 is realized by the following three steps:

a. judging the initial value of the communication coefficient between the injection wells and the production wells and the initial value of the time lag constant calculated in the S2 through constraint conditions, and rejecting unreasonable judging data; the constraint conditions comprise an injection-production inter-well communication coefficient constraint condition, a time lag constant constraint condition and a production inter-well interference constant constraint condition and are used for constraining an injection-production inter-well communication coefficient, a time lag constant and a production inter-well interference constant;

the communication condition of injection and production communication is greatly influenced by geological factors, and the communication coefficient, the time lag constant and the interference constant between production wells conform to geological knowledge, for example, the communication coefficient between injection and production wells which are far away should not be larger, the interference constant between production wells should not be negative, and the like. In order to make the obtained data conform to the geological knowledge of the oilfield block to be determined and further improve the rationality of the judgment data, constraint conditions need to be established to judge the rationality of the obtained data.

The established constraint conditions comprise an injection-production inter-well communication coefficient constraint condition, a time lag constant constraint condition and a production inter-well interference constant constraint condition.

Firstly, establishing a communication coefficient constraint condition between injection wells and production wells;

the method for establishing the communication coefficient constraint condition between the injection wells and the production wells comprises the following steps:

A. acquiring a limit influence distance formula between injection wells and production wells;

and the limit influence distance between the injection wells and the production wells is the corresponding well distance when the elliptic isobars formed in the limit wave area are tangent. In the limit wave area of the ellipse formed by one well, the direction with larger radius of the ellipse is along the direction of the object source, and the direction with smaller radius is vertical to the direction of the object source. If the well spacing exceeds the limit influence distance, the communication relation between the two wells is considered to be weak, and the communication coefficient between the injection wells and the production wells is 0.

Fig. 1 is a schematic diagram of the injection-production limit influence distance, and the injection-production limit influence distance shown in fig. 1 is calculated by taking an injection-production in an oil field block to be determined as an example. The upper left ellipse represents the limiting swept area of the injection well, with the major semi-axis a₁The minor semi-axis is b₁(ii) a The lower right ellipse represents the limiting swept area of the producing well, with the semi-major axis a₂The minor semi-axis is b₂(ii) a Theta is an included angle between the direction of the source and a connecting line between the injection well and the production well; r is_ijThe method is characterized in that the method is a connecting line between two points in the graph, namely the limit influence distance between injection wells and production wells, and the method is calculated according to an elliptic formula:

$r_{ij}={\left(\frac{{\cos }^2{\mathrm{\θ}}_{ij}}{{a_{1ij}}^2}+\frac{{\sin }^2{\mathrm{\θ}}_{ij}}{{b_{1ij}}^2}\right)}^{-\frac{1}{2}}+{\left(\frac{{\cos }^2{\mathrm{\θ}}_{ij}}{{a_{2ij}}^2}+\frac{{\sin }^2{\mathrm{\θ}}_{ij}}{{b_{2ij}}^2}\right)}^{-\frac{1}{2}}---\left(5\right)$

wherein r is_ijThe limit influence distance between the ith injection well and the jth production well is represented by meter; a is_1ij、a_2ijRespectively showing the major semi-axis and the minor semi-axis of an ellipse formed by taking the injection well as the production well as the center of the ellipse in the well pair formed by the ith injection well and the jth production well; b_1ij、b_2ijThe minor semi-axis and the meter of an ellipse formed by taking the injection well as the production well as the center of the well pair formed by the ith injection well and the jth production well respectively are shown; theta_ijThe included angle between the direction of the source and the connecting line of the injection well of the ith opening and the production well of the jth opening is expressed as degree; wherein, b_1ij、b_2ijOne half of the reasonable well spacing, theta, which can be comprehensively determined by numerical simulation of oil reservoir engineering_ijIs a known amount;

B. calculating a in step A_1ij、a_2ij；

According to the actual condition of an oil reservoir, the stratum permeability is a main factor influencing the limiting radius between injection wells and production wells, and is deduced according to an anisotropic stratum elliptic flow equation, and the following relations exist:

$\frac{a_{1ij}}{b_{1ij}}=\frac{a_{2ij}}{b_{2ij}}=\sqrt{\frac{k_{xij}}{k_{yij}}}---\left(6\right)$

wherein k is_xijAnd k_yijAverage permeability in the direction of X, Y for the ith injection well and the jth production well, respectively, 10^-3Square micron; a is_1ij、a_2ijThe major semi-axis and the minor semi-axis of an ellipse formed by taking the injection well as the center and taking the production well as the center in a well pair formed by the ith injection well and the jth production well respectively are meters; b_1ij、b_2ijA minor semi-axis, m, of an ellipse formed by centering the injection well and centering the production well in a well pair formed by the injection well and the production well of the ith port and the jth production well respectively; wherein k is_xij、k_yij、b_1ij、b_2ijIn known amounts.

C. Establishing a limit influence distance matrix:

$R=\left(\begin{array}{cccc}{r}_{11}& r_{12}& ...& r_{1N_{pro}}\\ r_{21}& r_{22}& ...& r_{2N_{pro}}\\ .& .& .& .\\ .& .& .& .\\ .& .& .& .\\ r_{N_{i}1}& r_{N_{i}1}& ...& r_{N_i{N}_{pro}}\end{array}\right)={\left(r_{ij}\right)}_{N_i\×N_{pro}}---\left(7\right)$

wherein r is_ijThe limit influence distance between the ith injection well and the jth production well is represented by meter; n is a radical of_iIndicating the number of injection wells, the mouth; n is a radical of_proIndicates the number of production wells, ports; wherein N is_i、N_proIs a known amount, r_ijCalculated by the step A, B;

D. establishing an injection-production well spacing matrix:

$D=\left(\begin{array}{cccc}{d}_{11}& d_{12}& ...& d_{1N_{pro}}\\ d_{21}& d_{22}& ...& d_{2N_{pro}}\\ .& .& .& .\\ .& .& .& .\\ .& .& .& .\\ d_{N_{i}1}& d_{N_{i}1}& ...& d_{N_i{N}_{pro}}\end{array}\right)={\left(d_{ij}\right)}_{N_i{N}_{pro}}---\left(8\right)$

wherein d is_ijRepresenting the distance between the ith injection well and the jth production well in meters; n is a radical of_iIndicating the number of injection wells, the mouth; n is a radical of_proIndicates the number of production wells, ports; wherein d is_ij、N_i、N_proIn known amounts.

E. Establishing a calculation influence coefficient matrix:

$A={\left(a_{ij}\right)}_{N_i\×N_{pro}}---\left(9\right)$

wherein, $a_{ij}=\left\{\begin{array}{cc}0& d_{ij}>r_{ij}\\ 1& d_{ij}\≤r_{ij}\end{array}\right.;$ d_ij、r_ijN_iindicating the number of injection wells, the mouth; n is a radical of_proIndicating the number of production wells, ports.

F. Establishing a communication coefficient constraint condition between injection wells and production wells;

by a in formula (9)_ijRestricting the communication coefficient between injection wells and production wells, and establishing the restriction condition of the communication coefficient between injection wells and production wells, namely:

$\begin{array}{ccc}0\≤\underset{i=1}{\overset{N_i}{\Σ}}{a}_{ij}{f}_{ij}\≤1& j=1,2,...,N_{pro}& a_{ij}=\left\{\begin{array}{cc}0& d_{ij}>r_{ij}\\ 1& d_{ij}\≤r_{ij}\end{array}\right.\end{array}---\left(10\right)$

secondly, establishing a time lag constant constraint condition;

to ensure computation of weight terms in an objective functionAndin the (0,1) range, the invention derives a reasonable range of time lag constants: 0.145 Deltat is less than or equal to tau_j1000 Δ t, the range of time lag constants being related to the time step Δ t.

Finally, establishing constraint conditions of interference constants among production wells;

since the interference between production wells cannot be negative, the interference constant of other production forming wells to the jth production well cannot be less than 0, α_j≥0。

The constraint condition is finally obtained as follows:

$s.t\left\{\begin{array}{c}\begin{array}{cc}0\≤\underset{i=1}{\overset{N_i}{\Σ}}{a}_{ij}{f}_{ij}\≤1,& j=1,2,...,N_{pro}\end{array}\\ 0.145\mathrm{\Δ}t\≤{\mathrm{\τ}}_j\≤1000\mathrm{\Δ}t\\ {\mathrm{\α}}_j\≥0\end{array}\right.---\left(11\right)$

substituting the optimized data of S1 into a formula (3) to obtain a result, and then judging the result according to a formula (11) of a communication coefficient constraint condition to obtain an initial value matrix of the communication coefficient between injection wells, wherein the initial value matrix is as follows:

TABLE 4 initial value matrix of communication coefficient between injection wells and production wells

The initial value of the time lag constant is equal to or more than 0.145 and equal to or more than 322 and equal to or more than 1000, and the initial value of the time lag constant is 322 days because the constraint condition is met.

As shown in fig. 6, the injection and production wells are connected on the injection and production well distribution map by lines with different thickness degrees according to the data in table 4, and the larger the initial connectivity coefficient is, the thicker the lines are, and the initial injection and production inter-well connectivity coefficient distribution map is further drawn.

b. Substituting the optimized data of S1 and the initial value of the communication coefficient between injection wells and the initial value of the time lag constant after the judgment of a into a target function, and calculating the communication coefficient between injection wells, the time lag constant and the interference constant between production wells when the value of the target function is smaller than the fitting error;

when the calculated fluid production capacity and the actual fluid production capacity are well fitted, the sum of squares of the difference values of the calculated fluid production capacity and the actual fluid production capacity approaches to 0, so that the objective function adopts a function for calculating the minimum value of the superposition value of the sum of squares of the difference values of the calculated fluid production capacity and the actual fluid production capacity of each production well in the oil field block to be determined in all time steps. Because the calculated liquid production amount and the actual liquid production amount cannot be completely fitted, a certain fitting error exists, and the fitting error is 0.1 in the process of distinguishing the high-water-content oil field block.

The objective function is the following equation:

$\min f\left(x\right)=\underset{k=1}{\overset{n}{\Σ}}\underset{j=1}{\overset{N_{pro}}{\Σ}}{\[q_j\left(k\right)-{\hat{q}}_j\left(k\right)\]}^2---\left(12\right)$

wherein q is_j(k) Representing the actual liquid production amount of the jth production well at the K time step, wherein the cubic meter is per day;representing the calculated liquid production amount of the jth production well at the K time step, wherein the cubic meter is per day; n represents the total calculation time step, month; n is a radical of_proRepresenting the total number of producing wells, ports.

The high water content oil field has the characteristics of dense injection and production well pattern and serious interference between production wells, so that an interference constant α between production wells is introduced when calculating the liquid production amount_jAnd represents the interference of other production forming wells to the jth production well.

Introduction of interference constant α between production wells_jThe post-calculated fluid production is expressed as:

${\hat{q}}_j\left(k\right)={\hat{q}}_j(k-1)e^{-\left(\frac{\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)}+(1-e^{-\left(\frac{\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)})\[\underset{{\mathrm{\τ}}_j}{\overset{N_i}{\Σ}}\left(f_{ij}{I}_i\right(k\left)\right)-{\mathrm{\α}}_j\]---\left(13\right)$

wherein,representing the calculated liquid production capacity of the jth production well on the k time step, cubic meters per day; Δ t represents the time step, month; f. of_ijRepresenting the communication coefficient between the injection well of the ith hole and the production well of the jth hole α_jIndicating the interference of other production forming wells on the jth production well; tau is_jRepresents the time lag constant, days, for the jth producer well; i is_i(k) And the water injection quantity of the injection well at the ith hole at the k time step is shown, and the cubic meter is taken every day.

Thus, the fluid production at the kth time point of the jth production well is expressed as the combined effect of the fluid production at the previous time point, the water injection at the surrounding injection well, and the interference at the surrounding production well.

The recursive operation is performed on equation (6) as follows:

$\begin{array}{c}{\hat{q}}_j\left(k\right)={\hat{q}}_j(k-1)e^{-\left(\frac{\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)}+(1-e^{-\left(\frac{\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)})\[\underset{i=1}{\overset{N_i}{\Σ}}\left(f_{ij}{I}_i\right(k\left)\right)-{\mathrm{\α}}_j\]\\ =\[{\hat{q}}_j(k-2)e^{-\left(\frac{\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)}+(1-e^{-\left(\frac{\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)})\[\underset{i=1}{\overset{N_i}{\Σ}}\left(f_{ij}{I}_i\right(k-1\left)\right)-{\mathrm{\α}}_j\]\]e^{-\left(\frac{\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)}+(1-e^{-\left(\frac{\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)})\[\underset{i=1}{\overset{N_i}{\Σ}}\left(f_{ij}{I}_i\right(k\left)\right)-{\mathrm{\α}}_j\]\\ ={\hat{q}}_j(k-3)e^{-\left(\frac{2\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)}+e^{-\left(\frac{2\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)}(1-e^{-\left(\frac{\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)})\[\underset{i=1}{\overset{N_i}{\Σ}}\left(f_{ij}{I}_i\right(k-1\left)\right)-{\mathrm{\α}}_j\]+(1-e^{-\left(\frac{\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)})\[\underset{i=1}{\overset{N_i}{\Σ}}\left(f_{ij}{I}_i\right(k\left)\right)-{\mathrm{\α}}_j\]\\ ={\hat{q}}_j(k-3)e^{-\left(\frac{3\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)}+e^{-\left(\frac{2\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)}(1-e^{-\left(\frac{\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)})\[\underset{i=1}{\overset{N_i}{\Σ}}\left(f_{ij}{I}_i\right(k-2\left)\right)-{\mathrm{\α}}_j\]+e^{-\left(\frac{\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)}(1-e^{-\left(\frac{\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)})\[\underset{i=1}{\overset{N_i}{\Σ}}\left(f_{ij}{I}_i\right(k-1\left)\right)-{\mathrm{\α}}_j\]\\ +(1-e^{-\left(\frac{\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)})\[\underset{i=1}{\overset{N_i}{\Σ}}\left(f_{ij}{I}_i\right(k\left)\right)-{\mathrm{\α}}_j\]\\ ......\\ ={\hat{q}}_j\left(0\right)e^{-\left(\frac{k\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)}+e^{-\left(\frac{\left(n-1\right)\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)}(1-e^{-\left(\frac{\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)})\[\underset{i=1}{\overset{N_i}{\Σ}}\left(f_{ij}{I}_i\right(k-n+1\left)\right)-{\mathrm{\α}}_j\]+e^{-\left(\frac{\left(n-2\right)\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)}(1-e^{-\left(\frac{\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)})\[\underset{i=1}{\overset{N_i}{\Σ}}\left(f_{ij}{I}_i\right(k-n+2\left)\right)-{\mathrm{\α}}_j\]\\ +...+(1-e^{-\left(\frac{\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)})\[\underset{i=1}{\overset{N_i}{\Σ}}\left(f_{ij}{I}_i\right(k\left)\right)-{\mathrm{\α}}_j\]\\ ={\hat{q}}_j\left(0\right)e^{-\left(\frac{k\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)}+\underset{p=1}{\overset{k}{\Σ}}{e}^{-\left(\frac{\left(k-p\right)\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)}(1-e^{-\left(\frac{\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)})\[\underset{i=1}{\overset{N_i}{\Σ}}\left(f_{ij}{I}_i\right(p\left)\right)-{\mathrm{\α}}_j\]\end{array}$

equation (6) becomes, through the above operation:

${\hat{q}}_j\left(k\right)={\hat{q}}_j\left(0\right)e^{-\left(\frac{k\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)}+\underset{p=1}{\overset{k}{\Σ}}\{e^{-\left(\frac{(k-p)\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)}(1-e^{-\frac{\mathrm{\Δ}t}{{\mathrm{\τ}}_j}})\[\underset{i=1}{\overset{N_i}{\Σ}}\left(f_{ij}{I}_i\right(p\left)\right)\]\}-\underset{p=1}{\overset{k}{\Σ}}{\mathrm{\α}}_j\[e^{-\frac{(k-p)\mathrm{\Δ}t}{{\mathrm{\τ}}_j}}(1-e^{\frac{\mathrm{\Δ}t}{{\mathrm{\τ}}_j}})\]---\left(14\right)$

wherein,the calculated liquid production amount of the jth production well on the k time step is expressed, and the unit is cubic meter per day;representing the initial liquid production of a jth production well, and the unit is cubic meter per day; Δ t represents a time step in months; f. of_ijRepresenting the communication coefficient between the injection well of the ith hole and the production well of the jth hole α_jIndicating interference of wells formed by other production with the jth production well; i is_i(p) represents the water injection quantity of the injection well at the ith hole in p time steps, and the unit is cubic meter per day; tau is_jRepresents the time lag constant for the jth production well in days; n is a radical of_iIndicating the number of injection wells in units of openings.

Substituting the formula (14) into the formula (12) to obtain a judging objective function of the communication condition between the injection wells and the production wells:

$\min f\left(x\right)=\underset{k=1}{\overset{n}{\Σ}}\underset{j=1}{\overset{N_{pro}}{\Σ}}{\{q_j\left(k\right)-{\hat{q}}_j\left(0\right)e^{-\left(\frac{k\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)}-\underset{p=1}{\overset{k}{\Σ}}\{e^{-\left(\frac{(k-p)\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)}(1-e^{\frac{\mathrm{\Δ}t}{{\mathrm{\τ}}_j}})\[\underset{i=1}{\overset{N_i}{\Σ}}\left(f_{ij}{I}_i\right(p\left)\right)\]\}+\underset{p=1}{\overset{k}{\Σ}}{\mathrm{\α}}_j\[e^{-\frac{(k-p)\mathrm{\Δ}t}{{\mathrm{\τ}}_j}}(1-e^{\frac{\mathrm{\Δ}t}{{\mathrm{\τ}}_j}})\]\}}^2---\left(15\right)$

and (3) substituting the data of the number of the injection wells and the production wells optimized by the S1, the total calculation time step, the water injection quantity of the injection wells, the liquid production quantity of the production wells, the injection-production well spacing and the like, and the initial values of the communication coefficient between the injection wells and the production wells and the initial values of the time lag constant in the table 4 into a formula (15), wherein the fitting error adopts 0.1, and then solving the communication coefficient between the injection wells and the production wells, the time lag constant and the interference constant between the production wells by using a sequential quadratic programming method.

c. And c, judging the communication coefficient among the injection wells, the time lag constant and the interference constant among the production wells obtained by calculation in the step b through the constraint condition, eliminating unreasonable judgment data, and obtaining the communication coefficient among the injection wells, the time lag constant and the interference constant among the production wells which are finally used for judging the communication condition among the injection wells.

And (c) judging the communication coefficient among injection wells, the time lag constant and the interference constant among production wells obtained by calculation in the step b by a constraint condition formula (11), and finally obtaining an injection-production inter-well communication condition matrix consisting of the communication coefficient among injection wells, the time lag constant and the interference constant among production wells, wherein the table is as follows:

TABLE 5 matrix of communication conditions between injection wells and production wells

S4: judging the strength of the communication condition between the injection wells and the production wells in the oil field block to be determined by utilizing the communication coefficient between the injection wells and the production wells calculated in the S3;

as shown in fig. 7, the data in table 5 are plotted on the injection and production well distribution map by connecting the injection and production wells by lines with different thickness degrees, and the larger the communication coefficient between the injection and production wells is, the thicker the lines are, so as to obtain the injection and production well communication coefficient distribution map shown in fig. 7.

The line thickness degree in FIG. 7 shows that there are communication conditions between G2 and the surrounding production wells G5-14, G28-24, G5-22 and G5-32, wherein the connectivity with G5-22 is strongest. The water well G28-28 has communication conditions with the surrounding water wells G28-26, G5-36, G5-34, G5-52, G32-28, G5-54, G32-30 and G5-58, wherein the communication conditions with a plurality of production wells G5-32, G5-34 and G32-28 are stronger. The G30-30 wells are communicated with the G5-54 wells, the G32-30 wells, the G5-58 wells and the G5-64 wells, wherein the G5-58 wells are communicated with the G5-58 wells. G5-1 is communicated with a plurality of wells such as G5-52, G32-28, G5-54, G32-30 and G5-64, wherein the communication with G5-52 is strong. The well G5 has communication conditions with G5-52, G32-30, G5-64, G34-32 and G36-32, wherein the communication conditions with G5-64 and G5-52 are stronger.

Judging the shortest time for the injected water to reach each production well by using the time lag constant calculated in the step S3;

the time for the injected water to reach each injection well fastest can be clearly analyzed through the time lag constant of each production well listed in table 5;

and judging that each production well is influenced by the interference of other production wells by using the interference constant among the production wells calculated by the S3.

The interference effect of each production well from other production wells can be clearly analyzed by the interference constants between production wells listed in table 5.

Fig. 4 is a schematic diagram of a first embodiment of a device for determining a communication status between injection wells and production wells according to the present invention. As shown in fig. 4, a first embodiment of the apparatus for determining the communication status between injection wells and production wells in the present invention includes the following modules:

a data preprocessing module P1 for data points for which data optimization of the oilfield block to be determined is not reasonable, the data of the oilfield block to be determined including: the number of injection wells, the number of production wells, the water injection amount of each injection well in each time step, the liquid production amount of each production well in each time step, the average permeability among injection and production wells and the injection and production well spacing; (ii) a

The data preprocessing module P1 optimizes unreasonable data points including:

setting the communication coefficient and the time lag constant between injection wells and production wells of the invalid well to be 0;

and setting the communication coefficient between the injection wells and the production wells of the injection-production conversion wells to be 0.

An initial value calculation module P2, which is used for calculating the initial value of the injection-production inter-well communication coefficient and the initial value of the time lag constant of the oil field block to be determined according to the optimized data of S1;

the initial value calculation module P2 calculates the initial value of the communication coefficient between the injection wells and the production wells by using the following formula:

$f_{ij}=\frac{\stackrel{\‾}{k_{ij}}/L_{ij}}{{\Σ}_{j=1}^{N_{pro}}\stackrel{\‾}{k_{ij}}/L_{ij}}$

wherein f is_ijRepresenting the communication coefficient between the injection well of the ith hole and the production well of the jth hole;the average permeability between the injection well of the ith and the production well of the jth is expressed by 10^-3Square micron; l is_ijThe well spacing of the ith injection well and the jth production well is expressed in meters; n is a radical of_proRepresenting the number of production wells in ports; wherein,L_ijare known;

the initial value of the time lag constant adopts the average time lag constant of the oilfield block to be determined;

the calculation step of the average time lag constant of the oilfield block to be determined comprises the following steps:

substituting the optimized data of the data preprocessing module P1 into an average time lag constant formula and calculating the average time lag constant when the formula value of the average time lag constant is smaller than a preset value;

the average time lag constant is expressed as:

$\min f\left(x\right)=\underset{k=1}{\overset{n}{\Σ}}{\[q\left(k\right)-q\left(0\right)e^{-\left(\frac{k}{\mathrm{\τ}}\right)}+\underset{k=1}{\overset{n}{\Σ}}\[(e_w+fI(k\left)\right)e^{-\frac{n-k}{\mathrm{\τ}}}(1-e^{-\frac{1}{\mathrm{\τ}}})\]\]}^2$

wherein n represents the total calculation time step in months; i (k) represents the water injection quantity of the block at the k time step, and the unit is cubic meter per day; q (k) represents the oil production of the block at the kth time step in cubic meters per day; q (0) represents the overall initial production of the block in cubic meters per day; f represents the block overall connectivity coefficient; τ represents the mean time lag constant in days; e.g. of the type_wRepresents external energy replenishment in joules; wherein I (k), q (k) are known amounts

And a result calculation module P3 for substituting the optimized data of the data preprocessing module P1 and the initial value of the communication coefficient between injection and production wells and the initial value of the time lag constant calculated in the initial value calculation module P2 into an objective function, and calculating the communication coefficient between injection and production wells, the time lag constant and the interference constant between production wells when the value of the objective function is smaller than the fitting error. The objective function is a function for calculating the minimum value of the superposition value of the sum of squares of the difference values of the calculated liquid production rate and the actual liquid production rate of each production well in the oil field block to be determined in all time steps;

the objective function is:

$\min f\left(x\right)=\underset{k=1}{\overset{n}{\Σ}}\underset{j=1}{\overset{N_{pro}}{\Σ}}\{q_j\left(k\right)-{\hat{q}}_j\left(0\right)e^{-\left(\frac{k\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)}-\underset{p=1}{\overset{k}{\Σ}}\{e^{-\left(\frac{(k-p)\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)}(1-e^{\frac{\mathrm{\Δ}t}{{\mathrm{\τ}}_j}})\[\underset{i=1}{\overset{N_i}{\Σ}}\left(f_{ij}{I}_i\right(p\left)\right)\]\}+\underset{p=1}{\overset{k}{\Σ}}{\mathrm{\α}}_j\[e^{-\frac{(k-p)\mathrm{\Δ}t}{{\mathrm{\τ}}_j}}(1-e^{\frac{\mathrm{\Δ}t}{{\mathrm{\τ}}_j}})\]\}$

wherein q is_j(k) Represents the actual fluid production at k time step in cubic meters per day;representing the initial production of the production well in cubic meters per day; Δ t represents the time step, month; f. of_ijRepresenting the communication coefficient between the injection well of the ith hole and the production well of the jth hole α_jRepresenting the interference constant of other production forming wells to the jth production well; i is_i(p) represents the water injection quantity of the injection well at the ith hole in p time steps, and the unit is cubic meter per day; tau is_jRepresents the time lag constant for the jth production well in days; n is a radical of_iIndicating the number of injection wells in units of openings; n is a radical of_proRepresenting the number of production wells in ports; n represents the total calculation time step in months; wherein q is_j(k)、Δt、I_i(p)、N_i、N_proAnd n is a known amount.

And the injection-production inter-well communication condition judgment module P4 is used for judging the strength of the communication condition between the injection wells and the production wells in the oil field block to be determined by using the communication coefficient between the injection wells and the production wells calculated by the result calculation module P3, judging the shortest time for the injection water in the oil field block to be determined to reach each production well by using the time lag constant calculated by the result calculation module P3, and judging the influence of the interference of other production wells on each production well in the oil field block to be determined by using the interference constant between the production wells calculated by the result calculation module P3.

In the embodiment, the influence of the interference among the production wells on the communication condition among the injection and production wells is considered, the interference constant among the production wells is introduced into the objective function, and the communication condition among the injection and production wells is judged by combining the communication coefficient among the injection and production wells, the time lag constant and the interference constant among the production wells, so that the rationality of judging the communication condition among the injection and production wells of the high-water-content oil field is enhanced, and the production work of the oil field is guided more favorably.

The initial value calculation module P2 and the injection-production well communication condition determination module P4 in the second embodiment of the injection-production well communication condition determination device of the present invention are the same as those in the first embodiment.

The data preprocessing module P1 in the second embodiment of the present invention is used to optimize unreasonable data points for the data of the oilfield block to be determined. The data of the oilfield block to be determined comprises: the number of injection wells, the number of production wells, the water injection amount of each injection well at each time step, the liquid production amount of each production well at each time step, the average permeability among injection and production wells, the injection and production well spacing, the included angle between the connecting line among the injection and production wells and the material source direction and the average permeability among the injection and production wells in the X, Y direction;

fig. 5 is a diagram illustrating the result calculation module P3 according to the second embodiment. As shown in fig. 5, the result calculation module P3 includes the following modules:

and the constraint module P3.1 is used for judging the initial value of the communication coefficient between the injection wells and the production wells and the initial value of the time lag constant calculated by the initial value calculation module P2 through constraint conditions and rejecting unreasonable judgment data.

The constraint conditions comprise an injection-production inter-well communication coefficient constraint condition, a time lag constant constraint condition and a production inter-well interference constant constraint condition and are used for constraining an injection-production inter-well communication coefficient, a time lag constant and a production inter-well interference constant;

the constraint conditions are as follows:

$s.t\left\{\begin{array}{c}\begin{array}{cc}0\≤\underset{i=1}{\overset{N_i}{\Σ}}{a}_{ij}{f}_{ij}\≤1,& j=1,2,...,N_{pro}\end{array}\\ 0.145\mathrm{\Δ}t\≤{\mathrm{\τ}}_j\≤1000\mathrm{\Δ}t\\ {\mathrm{\α}}_j\≥0\end{array}\right.$

wherein,Is a constraint condition of communication coefficient between injection wells and production wells, a_ijIn order to influence the coefficients of the effects, $a_{ij}=\left\{\begin{array}{cc}0& d_{ij}>r_{ij}\\ 1& d_{ij}\≤r_{ij}\end{array}\right.;$ r_ijby passing $r_{ij}={\left(\frac{{\cos }^2{\mathrm{\θ}}_{ij}}{{a_{1ij}}^2}+\frac{{\sin }^2{\mathrm{\θ}}_{ij}}{{b_{1ij}}^2}\right)}^{-\frac{1}{2}}+{\left(\frac{{\cos }^2{\mathrm{\θ}}_{ij}}{{a_{2ij}}^2}+\frac{{\sin }^2{\mathrm{\θ}}_{ij}}{{b_{2ij}}^2}\right)}^{-\frac{1}{2}},\frac{a_{1ij}}{b_{1ij}}=\frac{a_{2ij}}{b_{2ij}}=\sqrt{\frac{k_{xij}}{k_{yij}}}$ Calculating to obtain;

0.145Δt≤τ_jthe time lag constant constraint condition is not more than 1000 delta t;

α_jthe constraint condition of the interference constant between production wells is more than or equal to 0;

wherein d is_ijThe distance between the ith injection well and the jth production well is expressed in meters; r is_ijThe limit influence distance between the ith injection well and the jth production well is expressed in meters; a is_1ij、a_2ijRespectively representing the major semi-axes of ellipses formed by taking the injection well as the production well as the center of the well pair formed by the ith injection well and the jth production well, and the major semi-axes are meters; b_1ij、b_2ijRespectively representing the minor semi-axes of ellipses formed by taking the injection well as the production well as the center of the well pair formed by the ith injection well and the jth production well, and the unit is meter; theta_ijThe included angle between the direction of the source and the connecting line of the ith injection well and the jth production well is expressed in degrees; Δ t represents a time step in months; f. of_ijRepresenting the communication coefficient between the injection well of the ith hole and the production well of the jth hole α_jRepresenting the interference constant of other production forming wells to the jth production well; tau is_jRepresents the time lag constant for the jth production well in days; n is a radical of_proRepresenting the total number of producing wells in units of ports; wherein, b_1ij、b_2ijSimulating one half of the comprehensively determined reasonable well spacing by adopting an oil reservoir engineering numerical value; theta_ijAnd Δ t is a known quantity.

And a calculation submodule P3.2 for substituting the initial value of the communication coefficient between injection wells and the production well after the data are optimized by the data preprocessing module P1 and the initial value of the time lag constant after the data are judged by the initial value calculation module P2 into an objective function, and calculating the communication coefficient between injection wells, the time lag constant and the interference constant between production wells when the value of the objective function is smaller than the fitting error.

The objective function is:

$\min f\left(x\right)=\underset{k=1}{\overset{n}{\Σ}}\underset{j=1}{\overset{N_{pro}}{\Σ}}\{q_j\left(k\right)-{\hat{q}}_j\left(0\right)e^{-\left(\frac{k\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)}-\underset{p=1}{\overset{k}{\Σ}}\{e^{-\left(\frac{(k-p)\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)}(1-e^{\frac{\mathrm{\Δ}t}{{\mathrm{\τ}}_j}})\[\underset{i=1}{\overset{N_i}{\Σ}}\left(f_{ij}{I}_i\right(p\left)\right)\]\}+\underset{p=1}{\overset{k}{\Σ}}{\mathrm{\α}}_j\[e^{-\frac{(k-p)\mathrm{\Δ}t}{{\mathrm{\τ}}_j}}(1-e^{\frac{\mathrm{\Δ}t}{{\mathrm{\τ}}_j}})\]\}$

wherein q is_j(k) Represents the actual fluid production at k time step in cubic meters per day;representing the initial production of the production well in cubic meters per day; Δ t represents the time step, month; f. of_ijRepresenting the communication coefficient between the injection well of the ith hole and the production well of the jth hole α_jRepresenting the interference constant of other production forming wells to the jth production well; i is_i(p) represents the water injection quantity of the injection well at the ith hole in p time steps, and the unit is cubic meter per day; tau is_jRepresents the time lag constant for the jth production well in days; n is a radical of_iIndicating the number of injection wells in units of openings; n is a radical of_proRepresenting the number of production wells in ports; n represents the total calculation time step in months; wherein q is_j(k)、Δt、I_i(p)、N_i、N_proAnd n is a known amount.

And the fitting error adopts a communication coefficient among injection and production wells, a time lag constant and an interference constant among production wells as an optimal solution of an objective function when min f (x) is less than or equal to 0.1.

And when the calculated value of the objective function is smaller than the fitting error, the injection-production inter-well communication coefficient, the time lag constant and the production inter-well interference constant adopt a sequential quadratic programming method.

And a judging module P3.3 for judging the communication coefficient, the time lag constant and the interference constant among the injection wells, which are calculated in the calculating sub-module, among the injection wells and the production wells through the constraint conditions, eliminating unreasonable judging data and obtaining the communication coefficient, the time lag constant and the interference constant among the production wells which are finally used for judging the communication condition among the injection wells and the production wells.

In the second embodiment of the invention, the influence of the interference between the production wells on the communication condition between the injection wells and the production wells is considered, the interference constant between the production wells is introduced into the objective function, and the communication condition between the injection wells and the production wells is judged by combining the communication coefficient between the injection wells and the production wells, the time lag constant and the interference constant between the production wells, so that the rationality for judging the communication condition between the injection wells and the production wells of the high-water-content oil field is greatly enhanced, and the production work of the high-water-content oil field is guided more favorably.

Considering that the injection-production communication relationship is greatly influenced by geological factors, and the injection-production communication coefficient, the time lag constant and the production inter-well interference constant are consistent with geological knowledge, for example, a relatively large communication coefficient should not exist between injection-production wells with relatively long distances, the production inter-well interference constant should not be a negative value and the like, the second embodiment of the invention introduces a constraint condition into the established objective function, discriminates the calculated injection-production inter-well communication coefficient, the time lag constant and the production inter-well interference constant, eliminates unreasonable discrimination data, further improves the rationality of the calculated result, finally secondarily improves the rationality of discrimination of the injection-production inter-well communication condition of the high water-cut oil field, and is more favorable for guiding the fine injection-production of the high water-cut oil field.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be appreciated by those skilled in the art that the present invention is not limited by the embodiments described above, which are described in the specification only to illustrate the principles of the invention. The present invention is subject to various changes and modifications without departing from the spirit and scope of the invention, and such changes and modifications are intended to be included within the scope of the appended claims. The scope of the invention is defined by the claims in this specification and their equivalents.

Claims (10)

1. A method for judging the communication condition between injection wells and production wells is characterized by comprising the following steps:

s1: data points for which data optimization of the oilfield block to be determined is not reasonable, the data of the oilfield block to be determined comprising: the number of injection wells, the number of production wells, the water injection amount of each injection well in each time step, the liquid production amount of each production well in each time step, the average permeability among injection and production wells and the injection and production well spacing;

s2: according to the optimized data of S1, calculating an initial value of the injection-production interwell communication coefficient and an initial value of a time lag constant of the oil field block to be determined;

s3: substituting the optimized data of S1 and the initial value of the communication coefficient between injection wells and the production wells and the initial value of the time lag constant calculated in S2 into a target function, and calculating the communication coefficient between injection wells, the time lag constant and the interference constant between production wells when the value of the target function is smaller than the fitting error; the objective function is a function for calculating the minimum value of the superposition value of the sum of squares of the difference values of the calculated liquid production rate and the actual liquid production rate of each production well in the oil field block to be determined in all time steps;

s4: judging the strength of the communication condition between the injection wells and the production wells in the oil field block to be determined by utilizing the communication coefficient between the injection wells and the production wells calculated in the S3;

judging the shortest time for the injected water in the oil field block to reach each production well to be determined by utilizing the time lag constant calculated in the S3;

and judging that each production well in the oil field block to be determined is influenced by the interference of other production wells by using the interference constant among the production wells calculated by the S3.

2. The method for determining the communication status between injection wells and production wells according to claim 1,

the data of the oilfield block to be determined in S1 further includes: the included angle between the connecting line between the injection wells and the source direction and the average permeability between the injection wells and the production wells in the X, Y direction;

the step S4 is implemented by the following steps:

a. judging the initial value of the communication coefficient between the injection wells and the production wells and the initial value of the time lag constant calculated in the S2 through constraint conditions, and rejecting unreasonable judging data; the constraint conditions comprise an injection-production inter-well communication coefficient constraint condition, a time lag constant constraint condition and a production inter-well interference constant constraint condition and are used for constraining an injection-production inter-well communication coefficient, a time lag constant and a production inter-well interference constant;

b. substituting the optimized data of S1 and the initial value of the communication coefficient between injection wells and the initial value of the time lag constant after the judgment of a into an objective function, and calculating the communication coefficient between injection wells, the time lag constant and the interference constant between production wells when the value of the objective function is smaller than the preset value;

c. and (c) judging the communication coefficient among the injection wells and the production wells obtained by calculation in the step b through the constraint condition of the communication coefficient among the injection wells and the production wells, judging the time lag constant obtained by calculation in the step b through the constraint condition of the time lag constant, judging the interference constant among the production wells obtained by calculation in the step b through the constraint condition of the interference constant among the production wells, eliminating unreasonable judging data, and obtaining the communication coefficient among the injection wells, the time lag constant and the interference constant among the production wells which are finally used for judging the communication condition among the injection wells and the production wells.

3. A method for determining the communication status between injection and production wells according to claim 1 or 2, wherein the data points that are not optimized reasonably in S1 include:

setting the communication coefficient and the time lag constant between injection wells and production wells of the invalid well to be 0;

and setting the communication coefficient between the injection wells and the production wells of the injection-production conversion wells to be 0.

4. The method for determining the communication status between injection wells and production wells according to claim 1 or 2, wherein the step of calculating the initial value of the communication coefficient between injection wells and production wells of the oilfield block to be determined in S2 includes:

calculating to obtain an initial value of the communication coefficient between the injection wells and the production wells by using the following formula:

$f_{ij}=\frac{\stackrel{\‾}{k_{ij}}/L_{ij}}{{\Σ}_{j=1}^{N_{pro}}\stackrel{\‾}{k_{ij}}/L_{ij}}$

wherein f is_ijRepresenting the communication coefficient between the injection well of the ith hole and the production well of the jth hole;the average permeability between the injection well of the ith and the production well of the jth is expressed by 10^-3Square micron; l is_ijThe well spacing of the ith injection well and the jth production well is expressed in meters; n is a radical of_proRepresenting the number of production wells in ports; wherein N is_pro、L_ijIs a known value.

5. The method for judging the communication condition between the injection and production wells according to claim 1 or 2, wherein the initial value of the time lag constant is the average time lag constant of the oilfield block to be determined;

the calculation step of the average time lag constant of the oilfield block to be determined comprises the following steps:

substituting the optimized data of S1 into an average time lag constant formula and calculating the average time lag constant when the formula value of the average time lag constant is smaller than a preset value;

the average time lag constant is expressed as:

$\min f\left(x\right)=\underset{k=1}{\overset{n}{\Σ}}{\[q\left(k\right)-q\left(0\right)e^{-\left(\frac{k}{\mathrm{\τ}}\right)}+\underset{k=1}{\overset{n}{\Σ}}\[(e_w+fI(k\left)\right)e^{-\frac{n-k}{\mathrm{\τ}}}(1-e^{-\frac{1}{\mathrm{\τ}}})\]\]}^2$

wherein n represents the total calculation time step in months; i (k) represents the water injection quantity of the block at the k time step, and the unit is cubic meter per day; q (k) represents the oil production of the block at the kth time step in cubic meters per day; q (0) represents the overall initial production of the block in cubic meters per day; f represents the block overall connectivity coefficient; τ represents the mean time lag constant in days; e.g. of the type_wRepresents external energy replenishment in joules; wherein I (k), q (k) are known amounts.

6. The method for judging the communication condition between injection and production wells according to claim 1 or 2, wherein the fitting error is 0.1.

7. A method for determining the communication status between injection and production wells according to claim 1 or 2, wherein the objective function in S3 is:

$\min f\left(x\right)=\underset{k=1}{\overset{n}{\Σ}}\underset{j=1}{\overset{N_{pro}}{\Σ}}{\left\{q_j\left(k\right)-{\hat{q}}_j\left(0\right)e^{-\left(\frac{k\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)}-\underset{p=1}{\overset{k}{\Σ}}\left\{e^{-\left(\frac{\left(k-p\right)\mathrm{\Δ}t}{{\mathrm{\τ}}_j}\right)}\left(1-e^{\frac{\mathrm{\Δ}t}{{\mathrm{\τ}}_j}}\right)\[\underset{i=1}{\overset{N_l}{\Σ}}\left(f_{ij}{I}_i\left(p\right)\right)\]\right\}+\underset{p=1}{\overset{k}{\Σ}}{\mathrm{\α}}_j\[e^{-\frac{\left(k-p\right)\mathrm{\Δ}t}{{\mathrm{\τ}}_j}}\left(1-e^{\frac{\mathrm{\Δ}t}{{\mathrm{\τ}}_j}}\right)\]\right\}}^2$

wherein q is_j(k) Representing the actual liquid production amount of the jth production well in k time step, wherein the unit is cubic meter per day;representing the initial production of the jth production well in cubic meters per day, △ t representing the time step in months, f_ijRepresenting the communication coefficient between the injection well of the ith hole and the production well of the jth hole α_jRepresenting the interference constant of other production forming wells to the jth production well; i is_i(p) represents the water injection quantity of the injection well at the ith hole in p time steps, and the unit is cubic meter per day; tau is_jRepresents the time lag constant for the jth production well in days; n is a radical of_iIndicating the number of injection wells in units of openings; n is a radical of_proRepresenting the number of production wells in ports; n represents the total calculation time step in months; wherein q is_j(k)、△t、I_i(p)、N_i、N_proAnd n is a known amount.

8. The method for determining the communication status between the injection and production wells according to claim 2, wherein the constraint conditions for determining the initial value of the communication coefficient between the injection and production wells and the initial value of the time lag constant calculated in S2 through the constraint conditions are as follows:

$s.t\left\{\begin{array}{c}0\≤\underset{i=1}{\overset{N_i}{\Σ}}{a}_{ij}{f}_{ij}\≤1,j=1,2,...,N_{pro}\\ 0.145\mathrm{\Δ}t\≤{\mathrm{\τ}}_j\≤1000\mathrm{\Δ}t\\ {\mathrm{\α}}_j\≥0\end{array}\right.$

wherein,is a constraint condition of communication coefficient between injection wells and production wells, a_ijIn order to influence the coefficients of the effects, $a_{ij}=\left\{\begin{array}{cc}0& d_{ij}>r_{ij}\\ 1& d_{ij}\≤r_{ij}\end{array}\right.;$ said r_ijBy passing $r_{ij}={\left(\frac{{\cos }^2{\mathrm{\θ}}_{ij}}{{a_{1ij}}^2}+\frac{{\sin }^2{\mathrm{\θ}}_{ij}}{{b_{1ij}}^2}\right)}^{-\frac{1}{2}}+{\left(\frac{{\cos }^2{\mathrm{\θ}}_{ij}}{{a_{2ij}}^2}+\frac{{\sin }^2{\mathrm{\θ}}_{ij}}{{b_{2ij}}^2}\right)}^{-\frac{1}{2}},$ $\frac{a_{1ij}}{b_{1ij}}=\frac{a_{2ij}}{b_{2ij}}=\sqrt{\frac{k_{xij}}{k_{yij}}}$ Calculating to obtain;

0.145△t≤τ_jthe time lag constant constraint condition is not more than 1000 △ t;

α_jthe constraint condition of the interference constant between production wells is more than or equal to 0;

wherein d is_ijIndicating the i-th injection well and the j-th wellThe distance of the production well in meters; r is_ijThe limit influence distance between the ith injection well and the jth production well is expressed in meters; k is a radical of_xijAnd k_yijAverage permeability of the i th injection well and the j th production well in the direction of X, Y respectively and the unit is 10^-3Square micron; a is_1ij、a_2ijRespectively representing the major semi-axes of ellipses formed by taking the injection well as the production well as the center of the well pair formed by the ith injection well and the jth production well, and the major semi-axes are meters; b_1ij、b_2ijRespectively representing the minor semi-axes of ellipses formed by taking the injection well as the production well as the center of the well pair formed by the ith injection well and the jth production well, and the unit is meter; theta_ijExpressed as the angle between the source direction and the connecting line of the injection well of the ith opening and the production well of the jth opening in degrees, △ t expressed as the time step in months, f_ijRepresenting the communication coefficient between the injection well of the ith hole and the production well of the jth hole α_jRepresenting the interference constant of other production forming wells to the jth production well; tau is_jRepresents the time lag constant for the jth production well in days; n is a radical of_proRepresenting the total number of producing wells in units of ports; wherein, b_1ij、b_2ijSimulating one half of the comprehensively determined reasonable well spacing by adopting an oil reservoir engineering numerical value; theta_ij△ t are known quantities.

9. A device for judging the communication condition between injection wells and production wells is characterized by comprising

The data preprocessing module is used for optimizing unreasonable data points of the oilfield block to be determined, and the data of the oilfield block to be determined comprises: the number of injection wells, the number of production wells, the water injection amount of each injection well in each time step, the liquid production amount of each production well in each time step, the average permeability among injection and production wells and the injection and production well spacing;

the initial value calculation module is used for calculating an initial value of the communication coefficient between the injection wells and the production wells of the oil field block to be determined and an initial value of a time lag constant according to the data optimized by the data preprocessing module;

the result calculation module is used for substituting the data optimized by the data preprocessing module and the initial value of the communication coefficient between injection wells and the initial value of the time lag constant calculated by the initial value calculation module into an objective function, and calculating the communication coefficient between injection wells, the time lag constant and the interference constant between production wells when the value of the objective function is smaller than the fitting error; the objective function is a function for calculating the minimum value of the superposition value of the sum of squares of the difference values of the calculated liquid production rate and the actual liquid production rate of each production well in the oil field block to be determined in all time steps;

and the communication condition judging module is used for judging the strength of the communication condition between the injection wells and the production wells in the oil field block to be determined by utilizing the communication coefficient between the injection wells and the production wells calculated by the result calculating module, judging the shortest time for the injected water to reach each production well by utilizing the time lag constant calculated by the result calculating module, and judging the interference influence of other production wells on each production well by utilizing the interference constant between the production wells calculated by the result calculating module.

10. The apparatus according to claim 9, wherein the data of the field block to be determined in the data preprocessing module further includes an angle between a connecting line between injection wells and a source direction and an average permeability between injection wells in a direction of X, Y;

the result calculation module further comprises the following modules:

the constraint module is used for judging the initial value of the communication coefficient between the injection wells and the production wells and the initial value of the time lag constant calculated in the introduced initial value calculation module through constraint conditions and rejecting unreasonable judgment data; the constraint conditions comprise an injection-production inter-well communication coefficient constraint condition, a time lag constant constraint condition and a production inter-well interference constant constraint condition and are used for constraining an injection-production inter-well communication coefficient, a time lag constant and a production inter-well interference constant;

a calculation submodule for substituting the data optimized by the data preprocessing module and the initial value of the communication coefficient between injection wells and the production well after the judgment of the constraint module and the initial value of the time lag constant into a target function, and calculating the communication coefficient between injection wells, the time lag constant and the interference constant between production wells when the value of the target function is smaller than the fitting error;

and the judging module is used for judging the communication coefficient among the injection wells, the time lag constant and the interference constant among the production wells which are calculated in the calculating sub-module through the constraint condition, eliminating unreasonable judging data and obtaining the communication coefficient among the injection wells, the time lag constant and the interference constant among the production wells which are finally used for judging the communication condition among the injection wells.