Optimization method for adjustment well deployment in middle-late stage of fluvial facies reservoir development

Abstract

The application provides a method for optimizing deployment of adjustment wells in the middle and late stages of fluvial facies reservoir development, comprising: obtaining static parameters of old wells, grading the static parameters; obtaining dynamic parameters of injection wells around the old wells; grading the remaining oil potential of the old wells according to the static parameters and the dynamic parameters; preliminarily screening target adjustment areas; and determining the positions of the adjustment wells in the target adjustment areas. The application combines the sedimentary characteristics, seepage characteristics, water drive rules and actual injection development of the fluvial facies reservoirs to qualitatively and quantitatively grade the adjustment potential of the old wells in the adjustment areas, takes the grading results as the basis for selecting the adjustment wells, comprehensively considers the sedimentary characteristics, water drive rules, seepage characteristics and actual injection development of the fluvial facies sand bodies, and provides the method for deploying the adjustment well positions, which provides a reliable theoretical basis and technical support for tapping the local remaining oil, recovering the out-of-control reserves and producing the newly-added recoverable reserves of the fluvial facies reservoirs.

Description

Technical Field

[0001] This invention belongs to the field of oilfield development, specifically relating to a method for optimizing the deployment of adjustment wells in the mid-to-late stages of fluvial sedimentary reservoir development. Background Technology

[0002] Fluvial sedimentary oil reservoirs have good reservoir properties and relatively uniform water drive. However, as the development years increase and the reservoirs enter the middle and late stages of development, problems such as formation blockage, well casing damage, imperfect well network, and water injection and formation water propulsion become increasingly prominent, resulting in localized enrichment of residual oil and uncontrolled oil reserves.

[0003] Sedimentological studies indicate that for reservoirs deposited in large river systems, even with a relatively well network, uneven displacement of injected water due to variations in reservoir properties across the plane leads to uneven oil recovery. Along the main channel, permeability is high, displacement is rapid, and oil recovery is high; long-term water injection creates high-permeability channels, resulting in high water flooding near these channels and high oil recovery efficiency. Conversely, the riverbanks exhibit drastic property changes, with relatively weak permeability, slow water drive, and low or no water flooding, thus forming areas rich in residual oil.

[0004] Based on the existing well network, deploying adjustment wells to fully tap the potential of locally scattered remaining oil, restore uncontrolled reserves, and add new recoverable reserves has a significant effect on improving the level of reservoir development. The effectiveness of tapping the potential of remaining oil is mainly determined by two factors: the selection of potential areas is the foundation, and the optimization of the location of adjustment wells is the key.

[0005] For a long time, the selection of reservoir potential and the deployment of adjustment well locations in the mid-to-late stages of reservoir development have mainly relied on the qualitative judgment of reservoir engineers based on their experience. However, due to the strong heterogeneity and large differences in physical properties of reservoirs, it is difficult to determine the optimal location of local adjustment wells by artificial means, which has significant limitations. In recent years, researchers and engineers at home and abroad have proposed well location optimization design methods that combine optimization theory with numerical simulation. However, relying on the overall numerical simulation of the reservoir results in a large amount of computation and a long time consumption for the entire optimization process. It is often difficult to obtain satisfactory results within the limited amount of computation and time, and the timeliness of on-site production guidance is not strong. Summary of the Invention

[0006] The purpose of this invention is to provide a method for optimizing the deployment of adjustment wells in the mid-to-late stage of fluvial sedimentary facies oil reservoir development, so as to overcome the above-mentioned technical defects.

[0007] To address the aforementioned technical problems, this invention provides a method for optimizing the deployment of adjustment wells in the mid-to-late stages of fluvial sedimentary facies reservoir development, comprising: Obtain the static parameters of the old well and rate the static parameters; Obtain dynamic parameters of injection wells surrounding the old well; The remaining oil potential of old wells is rated based on the static parameters and the dynamic parameters. The target adjustment areas have been preliminarily identified; Within the target adjustment area, determine the location of the adjustment well.

[0008] Furthermore, obtain the static parameters of the old well, including: effective oil layer thickness h, permeability K, and porosity. Oil saturation S o Crude oil density ρ o Crude oil volume factor B oi Daily oil production capacity of a single well (q) and water cut (f) w Cumulative oil production per well (N) p .

[0009] Furthermore, rating the static parameters includes the following steps: Plot a scatter plot of the daily oil production capacity q of a single well against a single static parameter and fit the plot. Select the well-fitting parameter R. 2 A single static parameter ≥0.7 is used as a single static sensitive parameter. This single static parameter refers to the effective oil layer thickness h, permeability K, and oil saturation S. o or porosity ; Plot a scatter plot of the daily oil production capacity q of a single well versus the combined static parameters and fit the data. Select the well-fitting parameters R. 2 A combined static parameter ≥0.7 is used as a combined static sensitive parameter. This combined static parameter refers to the effective oil layer thickness h, permeability K, and oil saturation S of a single well. o and porosity The product of at least two parameters in the formula; Statistical analysis was performed on single static sensitive parameters and combined static sensitive parameters to define and classify their levels. By combining the ratings of single static sensitive parameters and combined static sensitive parameters, the rating with the most identical levels is selected as the comprehensive potential level of the static parameter.

[0010] Furthermore, dynamic parameters of the injection wells surrounding the old well are obtained, including: effective thickness of the oil layer in the injection well, residual oil saturation, bound water saturation, and cumulative water injection volume.

[0011] Further, based on the static parameters and the dynamic parameters, the remaining oil potential is calculated and rated, including the following steps: Step 101, calculate the controlled geological reserves N of a single well, using the following formula:

[0012] In the formula: A is the oil-bearing area controlled by a single well; h represents the effective thickness of the oil layer in a single well; Porosity; ρ o Density of crude oil; S oi This represents the initial oil saturation. B oi This is the crude oil volume coefficient; Step 102, calculate the remaining recoverable reserves N. r The calculation formula is as follows:

[0013] In the formula: N represents the geological reserves controlled by a single well; R e The final recovery rate; N p This refers to the cumulative oil production of a single well. Step 103, calculate the remaining oil saturation S or The calculation formula is as follows:

[0014] Step 104, calculate the recoverable reserves recovery degree E r The calculation formula is as follows:

[0015] Step 105, define the remaining recoverable reserves N r Residual oil saturation S or Recovery rate of recoverable reserves (E) r For dynamic sensitive parameters, statistical analysis of dynamic sensitive parameters is conducted, and the levels of all dynamic sensitive parameters are defined and classified separately. Step 106: Based on the ratings of the dynamic sensitive parameters, compare and select the rating with the most identical levels among the dynamic sensitive parameters as the level of remaining oil potential.

[0016] Furthermore, statistical analysis is conducted on single static sensitive parameters, combined static sensitive parameters, and dynamic sensitive parameters to define and classify them into levels, namely, Level I, Level II, and Level III.

[0017] Furthermore, the target adjustment area is initially screened out, specifically: the area where old wells and surrounding injection wells simultaneously meet the requirements of Level I single static sensitive parameters, Level I combined static sensitive parameters, and Level I dynamic sensitive parameters are selected as the target adjustment area.

[0018] Further, within the target adjustment area, determining the location of the adjustment well includes the following steps: Determine the water injection displacement radius centered on the water injection wells within the target adjustment area; Determine the oil well drainage area centered on the oil wells within the target adjustment area; Using the line connecting the oil production well and the water injection well located in the main direction of the sand body as a reference, draw a parallel line at a vertical distance Da from the line connecting the oil production well and the range determined by this line is the reasonable area where the adjustment well is located. The remaining oil-rich area outside the water injection displacement radius and the oil well drainage area is superimposed with the reasonable area where the adjustment well is located, and the superimposed position is the deployment position of the adjustment well.

[0019] Furthermore, the vertical distance D from the line connecting the oil production well and the water injection well located in the main direction of the sand body is taken as the reference. a Draw parallel lines, where D a The calculation formula is as follows:

[0020] In the formula: I a The distance index is dimensionless and ranges from 2 to 5. Er represents the recovery rate of recoverable reserves in the target area of ​​the oil wells.

[0021] The beneficial effects of this invention are as follows: Taking into full account the sedimentary characteristics, seepage features, water drive patterns, and actual production practices of fluvial reservoirs, a combination of qualitative and quantitative methods was used to determine the sensitive parameters affecting the effectiveness of adjustment wells. Based on the potential rating of the sensitive parameters, areas to be adjusted were selected, and the specific deployment locations of the adjustment wells were determined based on the geological and production dynamics of the surrounding old wells in the selected areas to be adjusted.

[0022] To make the above description of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0023] Figure 1 This is a scatter plot of the daily oil production capacity q of a single well versus the effective thickness h of the oil layer in a single well.

[0024] Figure 2 It is the daily oil production capacity q of a single well and the oil saturation S o Scatter plot.

[0025] Figure 3 This is a scatter plot of the daily oil production capacity q of a single well versus the permeability K.

[0026] Figure 4 It is the daily oil production capacity q of a single well and porosity Scatter plot.

[0027] Figure 5 It is the daily oil production capacity q of a single well and the combined static parameter S o Scatter plot of h.

[0028] Figure 6 It is the daily oil production capacity q of a single well and the combined static parameter S o Scatter plot of h·K.

[0029] Figure 7 It is the daily oil production capacity q of a single well and the combined static parameter S o ·h· Scatter plot of K.

[0030] Figure 8 The daily oil production capacity q of the deployed adjustment wells and I a Scatter plot.

[0031] Figure 9 It is the water cut of the deployed adjustment wells and I a Scatter plot.

[0032] Figure 10 This is a diagram showing the reasonable layout of adjustment wells. Detailed Implementation

[0033] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0034] It should be noted that, in this invention, the upper, lower, left, and right in the figure are regarded as the upper, lower, left, and right of the optimized deployment method for adjustment wells in the middle and late stages of river sedimentary reservoir development described in this specification.

[0035] Exemplary embodiments of the present invention will now be described with reference to the accompanying drawings. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to fully and completely disclose the invention and to fully convey its scope to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the drawings is not intended to limit the invention. In the drawings, the same units / elements are referred to by the same reference numerals.

[0036] Unless otherwise stated, the terms used herein (including technical terms) have their common meaning as understood by one of ordinary skill in the art. Furthermore, it is understood that terms defined in commonly used dictionaries should be understood to have a meaning consistent with the context of their relevant field, and not to be interpreted as having an idealized or overly formal meaning.

[0037] This invention provides a method for optimizing the deployment of adjustment wells in the mid-to-late stages of fluvial sedimentary facies reservoir development, including: Obtain the static parameters of the old well and rate the static parameters; Obtain dynamic parameters of injection wells surrounding the old well; The remaining oil potential of old wells is rated based on static and dynamic parameters. The target adjustment areas have been preliminarily identified; Within the target adjustment area, determine the location of the adjustment well.

[0038] The aforementioned "old wells" refer to oil wells in fluvial sedimentary reservoirs that have been exploited and have remaining oil-rich areas. Moreover, "old wells" is a collective term for several single wells within a certain range. This "certain range" can be a specific area within a fluvial sedimentary reservoir, without any specific restrictions.

[0039] Specifically, the static parameters of old wells include: the effective thickness of the oil layer in a single well. h Penetration rate K Porosity Oil saturation S o Crude oil density ρ o Crude oil volume coefficient B oi Daily oil production capacity per well q Moisture content f w Cumulative oil production per well N p .

[0040] The rating of static parameters includes the following steps: Drawing daily oil production capacity of a single well q By combining the scatter plot with a single static parameter and fitting the data, parameters with higher sensitivity, i.e., those that have a greater impact on the daily oil production capacity of oil wells, such as the goodness of fit, are selected. R 2 ≥0.7 The single static parameter, as a single static sensitive parameter, refers to the effective thickness of the oil layer. h Penetration rate K Oil saturation S o or porosity ; Drawing daily oil production capacity of a single well q By combining the scatter plots of the combined static parameters and fitting them, combined parameters with higher sensitivity, i.e., those with a greater impact on the daily oil production capacity of oil wells, such as the goodness of fit, are selected. R 2 ≥0.7 The combined static parameters, used as combined static sensitive parameters, refer to the effective thickness of the oil layer in a single well. h Penetration rate K Oil saturation S o and porosity The product of at least two parameters in the formula; Statistical analysis of single and combined static sensitive parameters is used to define and classify their levels. In this invention, a parameter rating standard is defined, and all oil wells' single and combined sensitive parameters are divided into three levels: single sensitive parameters are further divided into... Ⅰ class, Ⅱ class, Ⅲ Level, combined sensitive parameters are divided into Ⅰ class, Ⅱ class, Ⅲ class.

[0041] The ratings of both single and combined static sensitive parameters are compared and selected, with the rating with the most identical levels being used as the overall potential level for the static parameter. For example, if a well has two single sensitive parameters and one combined static sensitive parameter, the two single sensitive parameters are classified as follows: Ⅰ class, Ⅱ The level, and the only combined static sensitive parameter of this well was classified as Ⅰ If the rating is [level], then the remaining oil potential rating of this well is [level]. Ⅰ class.

[0042] Regarding the rating of sensitive parameters, this invention is based on the mine experience method, but other methods may also be used.

[0043] Next, it is necessary to obtain the dynamic parameters of the water injection wells around the old well and rate the remaining oil potential. The specific process is as follows: First, obtain the dynamic parameters of the injection wells surrounding the old well, including: the effective thickness of the oil layer in the injection wells. h w Residual oil saturation S or Bound water saturation S wc Cumulative water injection volume W i .

[0044] Then, based on static and dynamic parameters, as well as the volumetric method and material balance method, the controlled geological reserves, remaining recoverable reserves, remaining oil saturation, and recoverable reserve recovery degree of a single well are calculated. The remaining oil potential rating of old wells includes the following steps: Step 101: Calculate the controlled geological reserves of a single well. N The calculation formula is as follows:

[0045] In the formula: A To control the oil-bearing area of ​​a single well; h The effective thickness of the oil layer in a single well; Porosity; ρ o Density of crude oil; S oi This represents the initial oil saturation. B oi This is the crude oil volume coefficient; Step 102: Calculate the remaining recoverable reserves N r The calculation formula is as follows:

[0046] In the formula: N To control geological reserves for a single well; R e The final recovery rate; N p This refers to the cumulative oil production of a single well. Step 103, calculate the remaining oil saturation. S or The calculation formula is as follows:

[0047] Step 104: Calculate the recovery rate of recoverable reserves. E r The calculation formula is as follows:

[0048] Step 105, Define remaining recoverable reserves N r Residual oil saturation S or Recovery rate of recoverable reserves E r For dynamic sensitive parameters, statistical analysis of dynamic sensitive parameters is conducted, and the levels of all dynamic sensitive parameters are defined and classified separately. That is, the remaining recoverable reserves, remaining oil saturation, and recoverable reserve recovery degree are respectively divided into... Ⅰ class, Ⅱ class, Ⅲ class.

[0049] Step 106: Based on the ratings of the dynamic sensitive parameters, compare and select the rating with the most identical levels among the dynamic sensitive parameters as the level of remaining oil potential. For example, the remaining recoverable reserves and remaining oil saturation of the same well are both classified as... Ⅰ The level of recoverable reserves of this well is classified as follows: Ⅱ If the rating is [level], then the remaining oil potential rating of this well is [level]. Ⅰ class.

[0050] The initial screening identifies target adjustment areas, specifically referring to areas that simultaneously meet the criteria. Ⅰ Level single static sensitive parameter, Ⅰ Level combination static sensitivity parameters, Ⅰ The area where the old well and the surrounding injection wells are located, which are sensitive to dynamic parameters, is designated as the target adjustment area.

[0051] The target adjustment area is the area to be adjusted.

[0052] Within the target adjustment area, the location of the adjustment well is determined, including the following steps: Determine the water injection displacement radius centered on the water injection wells within the target adjustment area; Determine the oil well drainage area centered on the oil wells within the target adjustment area; Using the line connecting the oil production well and the water injection well along the main direction of the sand body as a reference, the vertical distance from this line is... D a Draw a parallel line, the range of which defines the reasonable area where the adjustment well is located; The remaining oil-rich area outside the water injection displacement radius and the oil well drainage area is superimposed with the reasonable area where the adjustment well is located, and the superimposed position is the deployment position of the adjustment well.

[0053] Regarding the determination of the water injection displacement radius, the material balance method can be used to determine the water injection sweep range of the area to be adjusted (i.e., the target adjustment area) based on dynamic data such as cumulative water injection volume and cumulative water production. The formula for calculating the displacement radius of the water injection well is as follows:

[0054]

[0055] In the formula: h w This refers to the effective thickness of the oil layer in the water injection well. I i The production well impact factor coefficient; This represents the average oil production of producing wells within the well network. q i Let be the oil production of the i-th well; R i For water drive radii in different directions; S or Residual oil saturation; S wc To bind water saturation; W i This represents the cumulative water injection volume; W p This represents the cumulative water production. E z This represents the longitudinal sweep efficiency of water drive. Porosity.

[0056] Regarding the determination of the oil well drainage area, the main method is to determine the oil well drainage radius of the area to be adjusted using the material balance method. The calculation formula is as follows:

[0057] In the formula: B oi This is the crude oil volume coefficient; N p This refers to the cumulative oil production of a single well. h e To ensure effective production thickness; ρ o Density of crude oil; S oi This represents the initial oil saturation. f w This refers to the moisture content.

[0058] In fluvial sedimentary reservoirs, water injection exhibits a clear directionality. Along the sand body direction, reservoir properties are good and water drive propagation is rapid, while lateral water line propagation is slow. To avoid the risk of high water cut, the adjustment well needs to be at a certain distance from the axis of the production well and the injection well located along the main sand body direction. This distance is positively correlated with the recovery rate of the production well. An adjustment well distance index is defined. I a The calculation formula is as follows:

[0059] therefore, D a The calculation formula is as follows:

[0060] In the formula: E r The recovery rate of recoverable reserves in the target area is calculated in step 104.

[0061] Regarding the adjustment of well distance index I aThe value can be obtained from historical data, as follows: Obtain the daily oil production capacity and water cut of deployed adjustment wells. D a , E r ; According to the calculation formula I a = D a / E r Calculation obtained I a ; Plot the daily oil production capacity of deployed adjustment wells and I a Scatter plot, see Figure 8 ; Plot the water cut of deployed adjustment wells and I a Scatter plot, see Figure 9 ; Taking all factors into consideration Figure 8 and Figure 9 ,when I a When the value is in the range of 2 to 5, the daily oil production capacity of a single well will not be too low, and the water cut will not be too high. Therefore, the adjustment well distance index is determined. I a The reasonable value is in the range of 2 to 5, therefore D a The value should be in the range of 2. E r ~5 E r Within the range.

[0062] The location of the adjustment well is determined as follows: Draw the water drive sweep area centered on the injection well; draw the drainage area centered on the production well; and use the line connecting the production well and the injection well along the main direction of the sand body as a reference, and calculate the vertical distance from this line. D a Draw a parallel line, and the area defined by this line is the reasonable area for the adjustment well. Overlay the remaining oil-rich area outside the water drive area of ​​the injection well and the oil drainage area of ​​the production well with the reasonable area of ​​the adjustment well to determine the optimal deployment location of the adjustment well and draw an adjustment well location map.

[0063] Example The following explanation uses a fluvial sedimentary reservoir as an example.

[0064] The reservoir has an average sand body thickness of 18.1 m, an average oil layer thickness of 7.9 m, an average permeability of 20.3 mD, an average porosity of 16.6%, an average oil saturation of 52.2%, an oil viscosity of 1.95 mPa·s, and an oil volume factor of 1.20.

[0065] The reservoir has well-developed bottom water with an average bottom water thickness of 8.0m. In recent years, the number of wells with casing failure has increased dramatically, and the rise in bottom water has caused serious water flooding problems in oil wells. In order to tap the remaining oil potential, restore the uncontrolled reserves, and utilize the newly added reserves, the above-mentioned method was used to deploy adjustment wells in the reservoir.

[0066] The deployment process is as follows: Step 1: Obtain static production data of oil wells (i.e., old wells) in the adjustment zone and determine the calculation parameters.

[0067] The main static production parameters of the primary well network of the fluvial sedimentary oil reservoir are shown in Table 1 below.

[0068] Table 1

[0069] Step two: Rate the potential of the static parameters of the old well.

[0070] First, the daily oil production capacity of a single well in the statistical adjustment area. q With the effective thickness of the oil layer h Penetration rate K Oil saturation S o Porosity The correlation between the daily oil production capacity of a single well and the correlation between the two factors. q Scatter plots with each individual static parameter, such as Figures 1-4 The effective thickness of the oil layer can be determined. h and oil saturation S o Daily oil production capacity of oil wells q The impact is significant; therefore, the effective thickness of the oil layer is selected. h and oil saturation S o As a single static sensitive parameter.

[0071] Then, calculate the daily oil production capacity of each well. q Combined static parameters S o ·h、S o ·h·K and S o ·h· ·K Scatter plot, such as Figures 5-7 It can be known that So ·h Daily oil production capacity of oil wells q The impact is significant, therefore, [the following was selected] S o ·h As a combined static sensitivity parameter.

[0072] Finally, based on the field experience method, statistical analysis was conducted on the single static sensitive parameters and combined static sensitive parameters of oil wells (i.e., old wells) in the adjustment area to define the rating criteria, as shown in Table 2 below.

[0073] Table 2

[0074] The comprehensive potential of static parameters is rated according to the static sensitivity parameter rating standard, as shown in Table 3 below.

[0075] Table 3

[0076] Step 3: Calculate the controlled geological reserves of a single well using the volumetric method and the material balance method. Then, calculate the recoverable reserves recovery rate, remaining recoverable reserves, and remaining oil saturation based on the controlled geological reserves of a single well. Rating the remaining oil potential of old wells in the adjustment area.

[0077] The recovery rate of recoverable reserves, remaining recoverable reserves, and remaining oil saturation are shown in Table 4 below.

[0078] Table 4

[0079] Statistical analysis was conducted on the recovery rate of the above-mentioned recoverable reserves, remaining recoverable reserves, and remaining oil saturation to define the rating criteria for dynamic sensitive parameters, as shown in Table 5 below.

[0080] Table 5

[0081] Based on the above dynamic sensitive parameter rating criteria, the remaining oil potential of old wells is comprehensively rated, as shown in Table 6 below.

[0082] Table 6

[0083] Step 4: Screen the comprehensive rating results of static sensitive parameters. I The rating is at level 1, and the remaining oil potential rating result is 1. I Oil wells of grade X3 were selected as wells to be adjusted, and two oil wells X3-6 and X3-12, along with their surrounding water injection wells X3-3, X3-5, and X3-13, were selected as the target adjustment area.

[0084] Step 5: Determine the appropriate location for the adjustment well.

[0085] 500, calculate the water drive radius of the injection wells within the target adjustment area, and determine the water injection coverage area, as shown in Table 7 below.

[0086] Table 7

[0087] 510. Determine the drainage area of ​​the two oil wells within the target adjustment area, as shown in Table 8 below.

[0088] Table 8

[0089] 520. Based on the distribution pattern of remaining oil in fluvial sandstone reservoirs, the remaining oil enrichment area is determined.

[0090] in accordance with D a =2 E r ~5 E r The calculations yielded the values ​​of two oil wells within the target adjustment area. D a See Table 9 below.

[0091] Table 9

[0092] 530. Taking injection wells X3-3, X3-5, and X3-13 as the center, determine the water drive sweep range; Determine the drainage area centered on oil production wells X3-6 and X3-12; Using the line connecting the oil production well and the water injection well along the main direction of the sand body as a reference, the vertical distance from this line is... D a Draw parallel lines ( Figure 10 In D a1 and D a2 The area defined by this line is the reasonable area for adjustment wells; by superimposing the remaining oil-rich area outside the water drive reach of injection wells and the drainage area of ​​production wells with the reasonable area of ​​adjustment wells, the reasonable location of adjustment wells is determined, see [link to relevant documentation]. Figure 10 .

[0093] 540. Two local adjustment wells, Xin X3-6 and Xin X3-12, were deployed in reasonable locations. After Xin X3-6 was put into production, the effective thickness of the oil layer was 10.6 meters, the initial daily oil production was 3.2 t / d, and the water cut was 23.7%. After Xin X3-12 was put into production, the effective thickness of the oil layer was 8.2 meters, the initial daily oil production was 2.1 t / d, and the water cut was 28.5%, proving that the method has a good application effect.

[0094] In summary, this invention, based on the static and dynamic characteristics of fluvial sedimentary reservoirs, combines qualitative and quantitative methods to determine the sensitive parameters affecting the effectiveness of adjustment wells. It selects areas to be adjusted based on the potential rating of these sensitive parameters, and determines the deployment location of adjustment wells based on the geological and production dynamic parameters of relevant old wells in the selected areas. This provides a reliable basis for tapping remaining oil potential, restoring uncontrolled reserves, and utilizing newly recoverable reserves in the mid-to-late stages of fluvial sedimentary reservoir development.

[0095] Those skilled in the art will understand that the above embodiments are specific examples of implementing the present invention, and in practical applications, various changes in form and detail may be made without departing from the spirit and scope of the present invention.

Claims

1. A method for optimizing the deployment of adjustment wells in the mid-to-late stage of fluvial sedimentary facies oil reservoir development, characterized in that... include: Obtain the static parameters of the old well and rate the static parameters; Obtain dynamic parameters of injection wells surrounding the old well; The remaining oil potential of old wells is rated based on the static parameters and the dynamic parameters. The target adjustment areas have been preliminarily identified; Within the target adjustment area, determine the location of the adjustment well; The static parameters obtained from old wells include: effective oil layer thickness h, permeability K, and porosity. Oil saturation S o Crude oil density ρ o Crude oil volume factor B oi Daily oil production capacity of a single well (q) and water cut (f) w Cumulative oil production per well (N) p ; The rating of the static parameters includes the following steps: Plot a scatter plot of the daily oil production capacity q of a single well against a single static parameter and fit the plot. Select the well-fitting parameter R. 2 A single static parameter with a value ≥0.7 is used as a single static sensitive parameter. This single static parameter refers to the effective oil layer thickness h, permeability K, and oil saturation S of a single well. o or porosity ; Plot a scatter plot of the daily oil production capacity q of a single well versus the combined static parameters and fit the data. Select the well-fitting parameters R. 2 A combined static parameter with a value ≥0.7 is used as a combined static sensitive parameter. This combined static parameter refers to the effective oil layer thickness h, permeability K, and oil saturation S of a single well. o and porosity The product of at least two parameters in the formula; Statistical analysis was performed on single static sensitive parameters and combined static sensitive parameters to define and classify their levels. By combining the ratings of single static sensitive parameters and combined static sensitive parameters, the rating with the most identical levels is selected as the comprehensive potential level of the static parameter. Determining the location of the adjustment well within the target adjustment area includes the following steps: Determine the water injection displacement radius centered on the water injection wells within the target adjustment area; Determine the oil well drainage area centered on the oil wells within the target adjustment area; Using the line connecting the oil production well and the water injection well located in the main direction of the sand body as a reference, draw a parallel line at a vertical distance Da from the line connecting the oil production well and the range determined by this line is the reasonable area where the adjustment well is located. The remaining oil-rich area outside the water injection displacement radius and the oil well drainage area is superimposed with the reasonable area where the adjustment well is located, and the superimposed position is the deployment position of the adjustment well.

2. The method for optimizing the deployment of adjustment wells in the mid-to-late stage of fluvial sedimentary facies reservoir development as described in claim 1, characterized in that, Obtain dynamic parameters of the injection wells surrounding the old well, including: effective thickness of the oil layer in the injection well, residual oil saturation, bound water saturation, and cumulative water injection volume.

3. The method for optimizing the deployment of adjustment wells in the mid-to-late stage of fluvial sedimentary facies reservoir development as described in claim 2, characterized in that, The remaining oil potential is calculated and rated based on the static parameters and the dynamic parameters, including the following steps: Step 101, calculate the controlled geological reserves N of a single well, using the following formula: N=100·A·h· ·r o ·S oi / B oi In the formula: A is the oil-bearing area controlled by a single well; h represents the effective thickness of the oil layer in a single well; Porosity; ρ o Density of crude oil; S oi This represents the initial oil saturation. B oi This is the crude oil volume coefficient; Step 102, calculate the remaining recoverable reserves N. r The calculation formula is as follows: In the formula: N represents the geological reserves controlled by a single well; R e The final recovery rate; N p This refers to the cumulative oil production of a single well. Step 103, calculate the remaining oil saturation S or The calculation formula is as follows: Step 104, calculate the recoverable reserves recovery degree E r The calculation formula is as follows: Step 105, define the remaining recoverable reserves N r Residual oil saturation S or Recovery rate of recoverable reserves (E) r For dynamic sensitive parameters, statistical analysis of dynamic sensitive parameters is conducted, and the levels of all dynamic sensitive parameters are defined and classified separately. Step 106: Based on the ratings of the dynamic sensitive parameters, compare and select the rating with the most identical levels among the dynamic sensitive parameters as the level of remaining oil potential.

4. The method for optimizing the deployment of adjustment wells in the mid-to-late stage of fluvial sedimentary facies reservoir development as described in claim 3, characterized in that, The statistical analysis of single static sensitive parameters, combined static sensitive parameters, and dynamic sensitive parameters defines and classifies them into levels I, II, and III.

5. The method for optimizing the deployment of adjustment wells in the mid-to-late stage of fluvial sedimentary facies reservoir development as described in claim 4, characterized in that, The target adjustment area was initially selected, specifically: the area where old wells and surrounding injection wells simultaneously meet the requirements of Level I single static sensitive parameters, Level I combined static sensitive parameters, and Level I dynamic sensitive parameters are selected as the target adjustment area.

6. The method for optimizing the deployment of adjustment wells in the mid-to-late stage of fluvial sedimentary facies reservoir development as described in claim 1, characterized in that, The reference is the line connecting the oil production well and the water injection well along the main direction of the sand body, and the vertical distance D from this line is... a Draw parallel lines, where D a The calculation formula is as follows: In the formula: I a The distance index is dimensionless and ranges from 2 to 5. E r Adjust the recovery rate of oil wells within the target area to determine the level of recovery of recoverable reserves.

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