A method for splitting water injection capacity in a connected direction based on big data analysis

Abstract

The application discloses a water injection well water injection capacity splitting method in a communication direction based on big data analysis, which comprises the following steps: step 1, identifying the communication relationship between oil and water wells; step 2, calculating the planar or longitudinal splitting coefficient of the water injection capacity of each water injection well in each communication direction; step 3, correcting the splitting coefficient of the water injection capacity of each water well in the longitudinal direction or the planar direction; and step 4, calculating the water injection capacity of the water injection well in each communication direction according to the corrected splitting coefficient in the longitudinal direction or the planar direction. The method can solve the problem of analyzing the oil and water distribution and the flow state in a small layer, has guiding significance for well pattern adjustment and preparation of a water injection adjustment scheme, and can effectively improve the oilfield development level.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of oil reservoir development, and is used for split calculation of water injection volume of water injection wells in each connected direction, and more particularly to a split method of water injection volume of water injection wells in connected directions based on big data analysis. BACKGROUND

[0002] With the gradual development of digital oilfield, it is currently necessary to solve the problem of realizing oilfield intelligentization gradually based on digitization and using information technology as a means.

[0003] Dynamic management of oil reservoir development is the core work of oilfield development. With the increase of the number of oil and water wells, dynamic management requires more and more refinement and precision. The previous focus on water injection volume of water injection wells without considering the water injection volume in each connected direction cannot meet the requirements of refined and precise oil reservoir development, and the split of water injection volume is related to the judgment of formation pressure and the adjustment of water injection scheme, which has important guiding significance for oilfield development. SUMMARY

[0004] The present application designs a judgment method based on big data analysis for the split of water injection volume of water injection wells in each connected direction. The method mainly applies a variety of dynamic and static data, applies the method of big data analysis to comprehensively analyze the historical dynamic monitoring data, combines the knowledge of oil reservoir theory and the historical dynamic change law, and splits the water injection volume of water injection wells in each connected direction. The method can quantitatively split the water injection volume in each direction connected with the water injection well, and provide accurate data support for dynamic analysis of oilfield development.

[0005] The present application is implemented by using the following technical solutions:

[0006] A split method of water injection volume of water injection wells in connected directions based on big data analysis, comprising:

[0007] Step 1, identifying the connected relationship between oil and water wells;

[0008] Step 2, calculating the split coefficient of the water injection volume of each water injection well in the plane or longitudinal direction of each connected direction;

[0009] Step 3, correcting the split coefficient of the water injection volume of each water injection well in the longitudinal or plane direction;

[0010] Step 4, calculating the water injection volume of each water injection well in each connected direction according to the corrected split coefficient in the longitudinal or plane direction.

[0011] The connected relationship between oil and water wells in step 1 is obtained by using the production dynamic and static data of oil and water wells and applying the analysis method of big data.

[0012] The splitting coefficients of the planes and the longitudinal directions in each communication direction are calculated based on the percolation theory and the water-electricity similarity principle, and the percolation resistance is calculated in combination with the reservoir geology and the production conditions.

[0013] The splitting coefficients are calculated as follows:

[0014] Step 2-1) assuming that there are m oil production wells O1, O2, …Om connected with the water injection well I i as the center. j … m ;

[0015] Step 2-2) defining the splitting coefficient λ affecting the production according to the theoretical value Q of the oil production well production kij as follows:

[0016]

[0017] In the formula, Q is the theoretical value of the oil production well production, λ kij is the splitting coefficient between the kth sublayer ith water injection well I i and the jth oil production well O j , k is the permeability; h is the effective thickness; μ is the viscosity; p i is the bottom hole pressure of the injection well; p wf is the bottom hole flowing pressure of the production well; Z is the interlayer interference coefficient; K is the sedimentary microfacies coefficient; D is the injection-production well spacing; E is the measure reconstruction coefficient.

[0018] Step 2-3) calculating the splitting coefficients of the directional injection amounts of each oil well in the plane and the longitudinal direction of the sublayer;

[0019] a. the longitudinal splitting coefficient between the ith water injection well I i and the jth oil production well O j :

[0020]

[0021] b. the kth sublayer plane splitting coefficient between the ith water injection well I i and the jth oil production well O j :

[0022]

[0023] The step 3 of correcting the splitting coefficient of the water injection amount of each water well in the longitudinal direction includes:

[0024] 3-1-1) establishing a jth oil well liquid production amount model at time t:

[0025]

[0026] In the formula, Ct -Comprehensive compression ratio; V p -Pore volume; - Formation average pressure; i(s) - Water injection rate per unit time; t, t0 are time points; q - Oil production per unit time; J - Oil recovery index; p wf - Bottom hole flowing pressure; λ kj - The injection-production connectivity coefficient between the Kth water injection well and the jth oil production well; τ j =c t V p / J j Let be the time constant for the production output of oil well j; s is the differential variable with respect to time.

[0027] 3-1-2) Input the production data of each oil well into the oil well production model to obtain the inter-well connectivity coefficient λ for each well. kj , λ kj The reaction is the injection volume of the kth minor layer on the connected oil well O. j The contribution ratio of liquid production;

[0028] 3-1-3) For the obtained longitudinal splitting coefficient R ij , using λ kj By performing a weighted average, the corrected value for the i-th injection well I is obtained. i With the jth oil well O j The longitudinal splitting coefficient R′ between ij ;

[0029]

[0030] Correct each well I i The splitting factor of the injection volume on the plane includes:

[0031] Step 3-2-1) Using historical injection well water intake profile data, obtain the injection volume of each injection well in each layer;

[0032] Step 3-2-2) Use the ratio of the injection volume of the inter-layer to the total injection volume of the well as the correction coefficient k for the splitting coefficient;

[0033] Step 3-2-3) For the splitting coefficient R of the plane k By correcting with a correction factor k, the corrected value of the i-th injection well I is obtained. i With the jth oil well O j The planar splitting coefficient R of the kth smallest layer between k ;

[0034] R′ k =R k K (10)

[0035] The water injection amount of the injection well in each communication direction includes:

[0036] a. Calculate the water injection amount influence value of the current injection well i on the longitudinal layer of the oil well j, or calculate the water injection amount influence value of the current injection well i on the transverse split of the oil well j;

[0037] b. According to the water injection amount influence value of the longitudinal layer or the water injection amount influence value of the transverse split, the water injection amount of each communication direction of the oil well j is calculated, and the single well water injection amount influence value of the current injection well i on the oil well j is obtained;

[0038] c. Finally, the water injection amount influence value of all injection wells in the region on the oil well j is calculated.

[0039] The water injection amount of the injection well in each communication direction includes:

[0040] Step 4-1) Calculate the water injection amount of the injection well on each small layer plane:

[0041] I ki = R' k × I (11)

[0042] In the formula: I- total well injection amount of the injection well; I ki - the water injection amount of the i-th injection well on the k-th small layer plane; R' k - the split coefficient of the k-th small layer plane;

[0043] Or, calculate the water injection amount of the injection well in the longitudinal direction:

[0044] I ki = R' ij × I (12)

[0045] In the formula: I- total well injection amount of the injection well; I ki - the total water injection amount of the i-th injection well in each communication direction of the k-th small layer; R' ij - the corrected longitudinal split coefficient between the i-th injection well I i and the j-th oil production well O j ;

[0046] Step 4-2) Water injection amount of injection well in each small layer in all communication directions:

[0047] I kij = λ kij × I ki (13)

[0048] In the formula: I kij - the water injection amount between the i-th injection well and the j-th oil production well on the k-th small layer plane; λ kij- the split coefficient between the i th injection well and the j th production well in the k th sublayer; I ki - the injection volume of the i th injection well in the k th sublayer plane;

[0049] Step 4-3) the injection volume of the injection well in each communication direction:

[0050]

[0051] wherein: I ij - the injection volume between the i th injection well and the j th production well; k - the sublayer number; I kij - the injection volume between the i th injection well and the j th production well in the k th sublayer plane.

[0052] Advantages and technical features of the present application:

[0053] 1. The split of the injection volume in the vertical and horizontal directions improves the oilfield development level, and is a basic work for analyzing the oil and water distribution and flow state in the sublayer, which has guiding significance for well pattern adjustment and preparation of injection adjustment scheme, and can effectively improve the oilfield development level.

[0054] 2. The method of big data analysis makes the information technology applied in the oil reservoir development, and changes the traditional manual dynamic and static data analysis into an intelligent comprehensive analysis method which is more intelligent, has a wider application data range and more comprehensive analysis results, so that the analysis is more accurate and the application effect is more ideal.

[0055] 3. Through the research and implementation of the method, a new method for improving the oilfield development level is explored, the mutual integration of the information field and the oil reservoir development field is actively explored, and a new mutual verification method for the cognition of the underground oil reservoir is provided. BRIEF DESCRIPTION OF DRAWINGS

[0056] Figure 1 the flow chart of the method of the present application;

[0057] Figure 2 the injection-production unit diagram constructed with the injection well as the center. DETAILED DESCRIPTION

[0058] As Figure 1As shown, it is a method flow chart of the application. The water injection amount splitting method in the communication direction based on big data analysis of the water injection well mainly includes five parts: first, using the production dynamic and static data of oil and water wells, applying the analysis method of big data, identifying the communication relationship between oil and water wells; second, based on the percolation theory and water electricity similarity principle, comprehensively considering the reservoir geology and mining conditions to calculate the percolation resistance and determine the splitting coefficient of the water injection amount of each water injection well in the plane and vertical direction of each communication direction; third, using the big data model and the capacitance resistance mechanism model to correct the splitting coefficient of the water injection amount of each water injection well in the vertical direction; fourth, using the historical water injection profile data of each water injection well to correct the splitting coefficient of the water injection amount of each water injection well in the plane; fifth, calculating the water injection amount of the water injection well in each communication direction.

[0059] As shown in the figure, it is an injection-production unit graph constructed with the water injection well as the center. Figure 2 As shown in the figure, it is an injection-production unit graph constructed with the water injection well as the center. (a) is an injection-production unit, (b) is a plane flow unit schematic diagram; (c) is a longitudinal flow unit schematic diagram.

[0060] First step: judging the communication relationship between oil and water wells, dividing the injection-production unit with the water injection well as the center;

[0061] Using the existing oilfield development production dynamic and static database, applying the analysis method of big data, summarizing the change law of historical production dynamic data, finding the mutual correlation relationship between oil and water wells; this step is realized by using the "judging the communication relationship between oil and water wells" in claim 1 of the patent with application number 202210105588.1 and the name of a method for judging the communication relationship between oil and water wells.

[0062] Then, using the knowledge of reservoir theory to confirm whether the correlation relationship exists connectivity, thereby judging the communication relationship between all oil and water wells, and constructing the injection-production unit with the water injection well as the center: taking the water injection well I i and the m oil production wells O1, O2, … O j ……, O m existing as the center and connected with it as the center.

[0063] Second step: determining the splitting coefficient of the water injection amount of each water injection well in the plane and vertical direction of each communication direction;

[0064] Based on the percolation theory and water electricity similarity principle, comprehensively considering the reservoir geology and mining conditions to calculate the percolation resistance and determine the reasonable splitting coefficient;

[0065] First, using the plane radial percolation model (1) to deduce the theoretical formula (2) of the oil well production

[0066]

[0067] The theoretical value of the oil well production:

[0068] where: k-permeability; h-effective thickness; μ-viscosity; p i - injection well bottom hole pressure; p wf - production well bottom hole flowing pressure; D-injection-production well spacing.

[0069] Equation (2) can show the main parameters affecting the production, but in real application, the reservoir conditions and development factors should also be considered:

[0070] Reservoir conditions-permeability, thickness, crude viscosity, sedimentary microfacies, interlayer interference

[0071] Development factors-injection-production well spacing, production pressure difference, measures (fracturing, acidizing, etc.)

[0072] Therefore, the impact of production splitting coefficient λ is redefined according to the theoretical value Q of the oil well production kij :

[0073]

[0074] where: k-permeability; h-effective thickness; μ-viscosity; p i - injection well bottom hole pressure; p wf - production well bottom hole flowing pressure; Z-interlayer interference coefficient; K-sedimentary microfacies coefficient; D-injection-production well spacing; E-measures transformation coefficient.

[0075] In practical application, take water injection well I1 as the center, O1, O2, O3, O4 as the four oil production wells connected thereto, and calculate the splitting coefficient of the injection amount of each oil well in the plane and longitudinal direction of the sublayer:

[0076] Table 1

[0077]

[0078] wherein the longitudinal splitting coefficient

[0079] the plane splitting coefficient

[0080] wherein: λ kij - the splitting coefficient between the i th injection well and the j th oil production well in the k th sublayer; R ij - the longitudinal splitting coefficient between the i th injection well and the j th oil production well; R k - the plane splitting coefficient of the k th sublayer; m is 4 and n is 3 in the example of Table 1.

[0081] Step 3:

[0082] 3-1) Correct the splitting coefficient of the injection volume of each well in the vertical direction.

[0083] 3-1-1) Connectivity analysis method based on a simplified physical model driven by big data: Capacitor-Resistance Model (CRM).

[0084] According to the law of conservation of mass, the volume of fluid accumulating over time in an injection-production system is equal to the algebraic sum of the volumes of the inflow and outflow fluids:

[0085]

[0086] According to the definition of the oil recovery index, we can obtain:

[0087]

[0088] Substituting the values ​​into the solution yields the production model for the j-th oil well at time t:

[0089]

[0090] In the formula, C t -Comprehensive compression ratio; V p -Pore volume; - Formation average pressure; i(s) - Water injection rate per unit time; t, t0 are time points; q - Oil production per unit time; J - Oil recovery index; p wf - Bottom hole flowing pressure; λ kj - The injection-production connectivity coefficient between the Kth water injection well and the jth oil production well; τ j =c t V p / J j Let be the time constant of the production output of oil well j; s is the differential variable with respect to time.

[0091] 3-1-2) Substitute the production data of each well into formula (8) to obtain the inter-well connectivity coefficient λ of each well. kj , λ kj The reaction is the injection volume of the kth minor layer on the connected oil well O. j The contribution ratio of the liquid production (the larger the coefficient, the stronger the connection, and the more water should be divided in that direction).

[0092] 3-1-3) For the obtained longitudinal splitting coefficient R ij , using λ kj By performing a weighted average, the corrected value for the i-th injection well I is obtained. i With the jth oil well O j The longitudinal splitting coefficient R′ between ij ;

[0093]

[0094] 3-2) Revision of each water injection well I i Injection volume on the plane split coefficient;

[0095] 3-2-1) First, using the historical injection well intake profile data, get the injection volume of each layer of each injection well;

[0096] 3-2-2) Use the ratio of layer injection volume to total well injection volume as the revision coefficient k of the split coefficient;

[0097] 3-2-3) For the split coefficient R of the plane k , using the revision coefficient k to revise, get the modified plane split coefficient R of the kth small layer between the ith injection well I i and the jth oil well O j ; k ;

[0098] R' k = R k K (10)

[0099] Fourth step: Calculate the injection volume of the injection well in each connected direction: a. Calculate the injection volume influence of the current injection well i on the vertical layer of the oil well j, or calculate the injection volume influence of the current injection well i on the horizontal split of the oil well j; b. According to the injection volume influence of the vertical layer or the injection volume influence of the horizontal split, calculate the injection volume of each connected direction of the oil well j, get the single well injection volume influence of the current injection well i on the oil well j; c. Finally, count the injection volume influence of all injection wells in the area on the oil well j.

[0100] 4-1) Calculate the injection volume of the injection well on each small layer plane:

[0101] I ki = R' k × I (11)

[0102] In the formula: I - injection well total injection volume;

[0103] I ki - the injection volume of the ith injection well on the kth small layer plane;

[0104] R' k - the kth small layer plane split coefficient;

[0105] Or, calculate the injection volume of the injection well in the vertical direction:

[0106] i ki = R' ij × I (12)

[0107] In the formula: I - injection well total injection volume; I ki- the total injection volume of the ith injection well in each communication direction of the kth sublayer; R' ij - the corrected injection volume of the ith injection well I i and the jth production well O j between them in the longitudinal direction;

[0108] 4-2) Injection volume of the injection well in each sublayer in all communication directions:

[0109] I kij = λ kij x I ki (13)

[0110] wherein: I kij - injection volume between the ith injection well and the jth production well in the kth sublayer plane;

[0111] λ kij - splitting coefficient between the ith injection well and the jth production well in the kth sublayer;

[0112] I ki - injection volume of the ith injection well in the kth sublayer plane;

[0113] 4-3) Injection volume of each injection well in each communication direction:

[0114]

[0115] wherein: I ij - injection volume between the ith injection well and the jth production well;

[0116] k - sublayer number;

[0117] I kij - injection volume between the ith injection well and the jth production well in the kth sublayer plane;

[0118] The above detailed description is used to explain and illustrate the present application, and is only a preferred embodiment of the present application, but is not a limitation on the present application, and any modification, equivalent replacement, improvement, etc. made to the present application falls within the protection scope of the present application.

Claims

1. A method for splitting water injection volume in the direction of communication based on big data analysis of water wells, characterized by, The method comprises the following steps: Step 1, identifying the connection relationship between oil wells and water wells; Step 2, calculating the planar or longitudinal splitting coefficient of the injection volume of each injection well in each connection direction; the splitting coefficient is calculated as follows: Step 2-1) Let's assume that there is a water injection well I i with m oil production wells O1, O2,..., O j ..., O m ; Step 2-2) Define the split factor λ affecting the production rate based on the theoretical value Q of the oil well production rate kij is: In the formula, Let Q be the theoretical value of the oil well's production. kij For the i-th injection well in the k-th sublayer i With the jth oil well O j Splitting coefficient, k - permeability; h - effective thickness; μ - viscosity; p i - Bottom hole pressure of the injection well; p wf - Bottom-outflow pressure of production well; Z - Inter-layer interference coefficient; K - Sedimentary microfacies coefficient; D - Injection-production well spacing; E - Stimulation and modification coefficient; Step 2-3) calculating the planar and longitudinal splitting coefficients of the injection volume of each oil well in each direction; a. the ith water injection well I i between the jth oil production well O j longitudinal split factor: b. the ith injection well I i between the jth oil production well O j the kth small layer plane splitting coefficient between the ith injection well I and the jth oil production well O Step 3, correcting the splitting coefficient of the injection volume of each water well in the longitudinal direction or the planar direction; The correction of the splitting coefficient of the injection volume of each water well in the longitudinal direction in step 3 comprises: 3-1-1) establishing a liquid production model of the jth oil well at time t: where C t - overall compressibility; V p - pore volume; - formation average pressure; i(s) - water injection rate per unit of time; t, t0 - time; q - liquid production rate per unit of time from the oil well; J - oil production index; p wf - bottom hole flowing pressure; λ kj - injection-production interconnection coefficient between the Kth water injection well and the jth oil production well; τ j = c t V p / J j is the time constant of the production rate of the oil well j; s is the differential variable with respect to time; 3-1-2) Bring the production data of each oil well into the well fluid production model to obtain the interwell connectivity coefficient λ of each well kj , λ kj represents the contribution ratio of the injection volume of the kth small layer to the fluid production of the connected oil well O j ; 3-1-3) For the obtained longitudinal splitting coefficient R ij , using λ kj By performing a weighted average, the corrected value for the i-th injection well I is obtained. i With the jth oil well O j The longitudinal splitting coefficient R′ between ij ; Step 4, calculating the injection volume of the injection well in each connection direction according to the corrected splitting coefficient in the longitudinal direction or the planar direction.

2. The method of claim 1, wherein the method is based on big data analysis of water injection rates in a connected direction. The connection relationship between oil wells and water wells in step 1 is obtained by using the production dynamic and static data of oil wells and water wells and applying the big data analysis method.

3. The method of claim 1, wherein the method is based on big data analysis of water injection rates in a connected direction. The planar and longitudinal splitting coefficients in each connection direction are calculated based on the percolation theory and the water-electricity similarity principle, and the percolation resistance is calculated in combination with the reservoir geology and the mining conditions.

4. The method of claim 1, wherein the method is based on big data analysis of water injection rates in a connected direction. Amendments to each water well I i Splitting coefficient of injection volume in the plane, including: Step 3-2-1) obtaining the injection volume of each injection well in each layer section by using the historical injection well water absorption profile data; Step 3-2-2) using the ratio of the layer injection volume to the whole well injection volume as the correction coefficient k of the splitting coefficient; Step 3 - 2 - 3) for the planar splitting coefficient R k , the modified planar splitting coefficient R between the ith injection well I and the jth production well O in the kth small layer is obtained by using the correction coefficient k i j k ;​​ R' k = R k K (10) 5. The method of claim 1, wherein, The calculation of the injection volume of the injection well in each connection direction comprises: a. calculating the injection volume influence value of the current injection well i on the longitudinal layered oil well j, or calculating the injection volume influence value of the current injection well i on the transverse splitting of the oil well j; b. calculating the injection volume of each connection direction of the oil well j according to the longitudinal layered injection volume influence value or the transverse splitting injection volume influence value, to obtain the single well injection volume influence value of the current injection well i on the oil well j; c. finally, the injection volume influence value of all injection wells in the region on the oil well j is calculated.

6. The method of claim 5, wherein the method is based on big data analysis of water injection rates in a connected direction. The calculation of the injection volume of the injection well in each connection direction specifically comprises: Step 4-1) calculating the injection volume of the injection well in each layer plane: I ki = R' k x I (11) In the formula: I - total injection rate of the water injection well; I ki - injection rate of the i-th water injection well on the k-th small layer plane; R' k - split coefficient of the k-th small layer plane Or, calculating the injection volume of the injection well in the longitudinal direction: I ki = R' ij x I (12) where: I - total injection rate of the i-th injection well; I ki - total injection rate of the i-th injection well in the k-th connected direction; R' ij - corrected injection rate of the i-th injection well I i - longitudinal splitting coefficient between the i-th injection well and the j-th production well O j ​ Step 4-2) the injection volume of the injection well in each layer in all connection directions: I kij = λ kij x I ki (13) wherein: I kij - the injection rate between the ith injection well and the jth production well in the kth subzone plane; λ kij - the split factor between the ith injection well and the jth production well in the kth subzone; I ki - the injection rate of the ith injection well in the kth subzone plane; Step 4-3) the injection volume of the injection well in each connection direction: where: I ij - injection rate between the ith injection well and the jth production well; k - small layer number; I kij - injection rate between the ith injection well and the jth production well on the kth small layer plane.

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