Method for calculating dosage of water shutoff and profile control agent for row-shaped well pattern of heterogeneous oil reservoir horizontal well

Abstract

The invention provides a heterogeneous oil reservoir horizontal well row-shaped well pattern water shutoff and profile control agent dosage calculation method which comprises the following steps: step 1, taking an injection-production well in which injection water flows along a high-permeability layer as a target, determining the type of injection water breakthrough, and determining whether the injection water breakthrough belongs to injection water breakthrough caused by reservoir heterogeneity or not; 2, the length L of a well section needing temporary plugging protection and the length Lhm of a well section needing deep adjustment and deep plugging are determined; 3, calculating the use amount Qprot of the temporary plugging agent; and 4, calculating the dosage of the plugging agent. The method for calculating the dosage of the water shutoff and profile control agent for the horizontal well row-shaped well pattern of the heterogeneous reservoir has the advantages that the dosage of the profile control agent for the horizontal well row-shaped well pattern can be calculated more accurately, and therefore the water drive development effect and the final recovery efficiency of the whole reservoir are improved.

Description

Technical Field

[0001] The present invention belongs to the field of computer technology, and in particular relates to a method for calculating dosage of a water plugging and profile control agent in a horizontal well pattern in a heterogeneous oil reservoir. Background Art

[0002] Thin-bed carbonate reservoirs in the Middle East are commonly operated using horizontal wells to increase reservoir contact area. The complexity of highly heterogeneous reservoirs is reflected in the lateral heterogeneity, vertical inter-layer differences, and complex multimodal porosity and permeability relationships. Furthermore, due to the limitations of early completion technologies, horizontal wells were often completed using open-hole methods for general injection and production. This resulted in poor re-entry of tubing and tools, and a lack of follow-up methods to resolve inter-layer discrepancies, making monitoring and stratification measures difficult to implement.

[0003] Once a reservoir enters the full waterflooding phase, due to differences in physical properties both horizontally and vertically, the injected water will initially penetrate these layers, leading to premature water breakthrough in the wells. As waterflooding progresses, the dominant water channeling becomes increasingly severe, resulting in ineffective circulation of the injected water and a rapid onset of high water cut in the wells. High water cut suppresses oil production in individual wells, and overall reservoir development results in horizontal production wells experiencing high water cuts and low recovery rates, leading to low overall waterflooding efficiency. Adjusting the injection-production system for oil and water wells can, in the short term, address the high water cut in these wells and improve the overall effectiveness of waterflooding in the reservoir. However, because the fundamental differences between the horizontal and interlayer structures have not been addressed, significant amounts of residual oil remain in areas beyond the reach of the injected water, limiting their impact on waterflooding effectiveness.

[0004] For this type of heterogeneous carbonate reservoir, it is necessary to use a combination of deep adjustment and deep plugging. By deep adjustment at the injection end and deep plugging at the production end, deep plugging of the high permeability layer is carried out at both the injection and production ends. This allows for human intervention in the seepage field, reducing or even eliminating the water injection sweep in flooded areas and expanding the water injection sweep volume in low-water-flooded and non-flooded areas. While plugging, reservoir protection is strengthened, and temporary plugging is performed on water-producing or low-water-producing well sections to maximize the protection of the main oil-producing sections of the oil well from damage caused by chemical injection. This achieves the goal of reducing water cut in a single well and controlling water and increasing oil production in the entire reservoir, thereby improving the water flooding development effect of the entire reservoir.

[0005] Calculating the dosage of chemical agents for water plugging and profile control is crucial. Existing chemical water plugging and profile control methods for horizontal wells lack reservoir protection, and chemical dosage calculations are mostly based on physical parameters given by geological reservoirs or production and injection profile monitoring results. For oil and water wells where profile monitoring results cannot be obtained, there is no effective method, and the only basis is reservoir physical parameters. Well selection mostly relies on the injection and production dynamics of injection and production wells and geological reservoir analysis. There is no solution to the difficulty in obtaining production and injection profile monitoring data due to poor wellbore re-entry, and the application of oilfield production, monitoring, and related data is insufficient. Therefore, it is necessary to design a method for calculating the dosage of plugging agents for horizontal well patterns specifically for heterogeneous carbonate reservoirs. Summary of the Invention

[0006] To solve the above problems, the present disclosure provides a method for calculating the dosage of water plugging and profile control agents in a horizontal well pattern in a heterogeneous oil reservoir, so as to more accurately calculate the dosage of water plugging and profile control agents in the horizontal well pattern, thereby improving the water flooding development effect and ultimate recovery rate of the entire oil reservoir.

[0007] The present invention discloses a method for calculating the dosage of a water plugging and profile control agent in a horizontal well pattern in a heterogeneous oil reservoir, comprising the following steps:

[0008] Step 1: Taking the injection-production wells where the injected water flows along the high permeability layer as the target, determine the type of injected water breakthrough and whether it is caused by reservoir heterogeneity;

[0009] Step 2: Determine the length L of the well section that needs temporary plugging protection and the length L of the well section that needs deep plugging. hm ;

[0010] Step 3: Calculate the temporary plugging agent dosage Q prot ;

[0011] Step 4: Calculate the amount of plugging agent.

[0012] The present invention also discloses an electronic device, comprising at least one processor and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the method for calculating the dosage of water plugging and profile control agents in a horizontal well pattern in a heterogeneous oil reservoir.

[0013] The present invention also discloses a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the method for calculating the dosage of a water plugging and profile control agent for a horizontal well pattern in a heterogeneous oil reservoir is implemented.

[0014] Compared with the prior art, the present disclosure has the following advantages:

[0015] The present invention provides a method for calculating the dosage of water plugging and profile control agents for horizontal well patterns in heterogeneous oil reservoirs. The method is a method for calculating the dosage of agents based on the production and injection profile, well test interpretation, and differences in physical parameters of the horizontal sections, and based on the construction purpose. The method uses temporary plugging and protection of the reservoir combined with deep adjustment and deep plugging as a technical strategy, and comprehensively applies geology, oil reservoirs, production dynamics, and oilfield monitoring results. The calculation of the dosage of water plugging and profile control agents for horizontal well patterns in heterogeneous oil reservoirs is achieved through the following steps 1 to 4. The specific calculation process includes the following steps: Step 1: Taking the injection and production wells where the injected water flows along the high permeability layer as the target, determine the type of injected water breakthrough, whether it is an injected water breakthrough caused by reservoir heterogeneity; Step 2: Determine the length L of the well section that needs temporary plugging and protection and the length L of the well section that needs deep adjustment and deep plugging. hm ; Step 3: Calculate the temporary plugging agent dosage Q prot ; Step 4: Calculate the amount of plugging agent.

[0016] The method for calculating the dosage of water plugging and profile control agents for a horizontal well pattern in a heterogeneous oil reservoir of the present invention has the advantages of more accurately calculating the dosage of water plugging and profile control agents for the horizontal well pattern, thereby improving the water flooding development effect and ultimate recovery rate of the entire oil reservoir.

[0017] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 A flow chart showing the method of the present invention is shown;

[0020] Figure 2 A plan view of the horizontal well plugging agent distribution of the present invention;

[0021] Figure 3 The production curve of the production well AD1-7-3H in an oil field in the Middle East is shown;

[0022] Figure 4 The water flooding characteristic curve of the production well AD1-7-3H in an oil field in the Middle East is shown;

[0023] Figure 5The diagram shows the well penetration diagram of the production well AD1-7-3H in an oil field in the Middle East;

[0024] Figure 6 A schematic diagram showing the MHI analysis of water flooding effects of production wells within the well group AD1-7-3H in an oil field in the Middle East. DETAILED DESCRIPTION

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0026] The present invention discloses a method for calculating the dosage of a water plugging and profile control agent in a horizontal well pattern in a heterogeneous oil reservoir, comprising the following steps:

[0027] Step 1: Taking the injection-production wells where the injected water flows along the high permeability layer as the target, determine the type of injected water breakthrough and whether it is caused by reservoir heterogeneity;

[0028] Step 2: Determine the length L of the well section that needs temporary plugging protection and the length L of the well section that needs deep plugging. hm ;

[0029] Step 3: Calculate the temporary plugging agent dosage Q prot ;

[0030] Step 4: Calculate the amount of plugging agent.

[0031] In specific implementation, when selecting an injection-production well where the injected water flows along the high permeability layer, if the injection-production well has profile monitoring results, the profile monitoring results are used in combination with the corresponding formation physical properties to determine whether the injection-production well is an injection-production well where the injected water flows along the high permeability layer.

[0032] In specific implementation, when selecting an injection-production well where the injected water flows along the high permeability layer, if there is no profile monitoring result for the injection-production well, the number of peaks of the tracer curve of the injection well is used to determine whether the injection-production well is an injection-production well where the injected water flows along the high permeability layer.

[0033] For oil and water wells with profile monitoring results, the selection process can be based on the profile monitoring results combined with the corresponding formation physical properties. For oil and water wells without profile monitoring results, the selection process can be based on the number of peaks in the tracer curve of the wells with injection. The number of tracer peaks reflects the number of injected water channels.

[0034] In specific implementation, in step 1, the main controlling factor of the injection water breakthrough is first determined, and then it is determined whether the injection water breakthrough of the production well is caused by reservoir heterogeneity.

[0035] In specific implementation, dynamic and static models, production performance, injection-production pressure response and water drive characteristic curves are used to determine the main controlling factors of injected water breakthrough and to determine whether the injected water breakthrough in production wells is caused by reservoir heterogeneity.

[0036] like Figure 1 The method for calculating the dosage of water plugging and profile control agents for horizontal well patterns in heterogeneous oil reservoirs of the present invention uses temporary reservoir plugging and protection combined with deep adjustment and deep plugging as a technical strategy, and comprehensively applies geology, oil reservoirs, production dynamics and oilfield monitoring results to calculate the dosage of water plugging and profile control agents. Before calculation, it is necessary to first clarify the type of injected water breakthrough, and target the injection and production wells where the injected water flows along the high permeability layer to ensure the effectiveness of water plugging and profile control. By combining dynamic and static methods, the main controlling factors of injected water breakthrough are judged from dynamic and static models, production dynamics, injection and production pressure response and water drive characteristic curves, and it is determined that the injected water breakthrough in the production wells is caused by reservoir heterogeneity.

[0037] For similar wells within the same injection-production well group, the MHI method can be used to screen out wells with poor water flooding development effects as target wells for water plugging, thereby ensuring the effectiveness of profile adjustment and water plugging. The MHI index method effectively analyzes the actual situation of oil and water wells by selecting relevant parameters and calculating the MHI value of the parameters, thereby determining whether the oil and water wells have inefficient circulation. For example, when evaluating the working status of a certain oil well, the parameter selected is daily oil production (in actual calculations, parameters such as daily oil production, daily water production, and water content can be arbitrarily selected). If the calculated MHI value of the well's daily oil production is greater than 0, it means that the well's daily oil production at the evaluation time point is higher than the average daily oil production of the well during the evaluation period; otherwise, it means that the well's daily oil production at the evaluation time point is lower than the average daily oil production of the well during the evaluation period, thereby qualitatively describing the strength of the well's oil production capacity. Researchers can use the MHI index method to quickly identify inefficient oil wells and inefficient water wells, thereby adjusting the working system and improving water injection efficiency. The calculation formula for the MHI method screening is shown in the following formula (1).

[0038]

[0039] In formula (1), MHI fluid is the heterogeneity coefficient, t max For the evaluation period, Fluid well is the daily oil production of a single well at any time point, in cubic meters per day; Fluid avg The average daily oil production of a single well in a certain period of time, in cubic meters per day; Fluid maxThe maximum daily oil production of a single well in a certain period of time, in cubic meters per day; Fluid min It is the minimum daily oil production of a single well in a certain period of time, in cubic meters per day.

[0040] In the specific implementation, in step 2, for the oil and water wells with injection and production profiles, the length L of the well section that needs temporary plugging protection and the length L of the well section that needs deep adjustment and deep plugging are determined by the injection and production profile test results. hm .

[0041] Temporary plugging protection combined with deep adjustment and deep plugging, it is necessary to determine the length L of the well section that needs temporary plugging protection and the length L of the well section that needs deep adjustment and deep plugging hm The section of the oil well that needs temporary plugging and protection is the main oil-producing section. The section of the oil well that needs deep plugging and protection is the section with high water content. The section of the water injection well that needs temporary plugging and protection is the section with normal water absorption capacity. The section of the water injection well that needs deep adjustment is the strong water absorption section corresponding to the high permeability layer. For oil and water wells with injection and production profiles, the length L of the section that needs temporary plugging and protection and the length L of the section that needs deep plugging and deep adjustment can be determined based on the injection and production profile test results. hm For oil and water wells where injection and production profile monitoring cannot be obtained due to poor wellbore re-entry, the lengths of the above two well sections can be determined by interpreting the results of the irregular production profile model through well testing.

[0042] In the specific implementation, in step 3, the temporary plugging agent dosage Q prot The calculation formula is shown in the following formula (2);

[0043]

[0044] In formula (2), Q prot is the dosage of temporary plugging protective agent, in kilograms; k is the thickness of the temporary plugging agent, in kilograms / square meter; L is the length of the horizontal well section, in meters; r is the radius of the horizontal well section, in meters; c is the effective concentration of the temporary plugging agent, in kilograms / cubic meter.

[0045] When calculating specifically, the dosage of temporary plugging agent Q prot The length of the entire horizontal well section is the length of the temporary plugging protection well section L. The particle size of the temporary plugging agent should match the pore throat characteristics of the formation to ensure that the temporary plugging agent can be spread on the well wall of the well section that needs temporary plugging protection and can enter the deep formation of the well section that needs to be plugged along the large pore channel. In the case where there are multiple sections of the well section that needs temporary plugging protection, the temporary plugging agent dosage Q prot The temporary plugging agent dosage can be obtained by calculating the single segment separately and accumulating the results. prot The calculation formula is shown in formula (2).

[0046] In specific implementation, the amount of plugging agent used includes the amount of main plugging segment plug Q main The amount of strong plugging segment Q strong.

[0047] Deep plugging and deep adjustment adopts multi-segment plugging. The first segment plugging is the main plugging segment plugging, followed by strong plugging segments. The calculation of each segment plugging volume is based on the length of the well section to be plugged, the formation porosity, the residual oil saturation of the corresponding formation of each segment, and the set plugging agent front advancement depth. See the schematic diagram Figure 2 Main plugging agent slug Q main The calculation formula of Q is shown in formula (3). strong The calculation formula of is shown in formula (4). For horizontal wells with large differences in physical properties in the well sections to be plugged, the horizontal section can be divided into multiple sections based on the physical properties, and the total amount of plugging in each section can be obtained by calculating and accumulating the results of each section.

[0048] Q main =(π(D1 2 -D2 2 )+2L hm (D1-D2))*h*Φ*(1-S or ) (3)

[0049] Q strong =(πD2 2 +2L hm D2)*h*Φ*(1-S or ) (4)

[0050] In formula (3) and formula (4), Q main The amount of plug used for the main plugging section, in cubic meters; Q strong is the amount of strong plugging slug, in cubic meters; L hm is the length of the horizontal well section to be plugged, in meters; D1 is the lateral setting depth of the main plugging section front edge, in meters; D2 is the lateral setting depth of the strong plugging section front edge, in meters; h is the formation thickness, in meters; Φ is the formation porosity of the horizontal well section to be plugged, expressed as a decimal in calculation; S or It is the residual oil saturation of the horizontal well section to be plugged.

[0051] This invention was implemented in a heterogeneous carbonate reservoir in an oil field in the Middle East. This reservoir is a stratified, edge-water reservoir. It was developed using a horizontal well pattern with top production and bottom water injection. A high-permeability layer nearly one meter thick was distributed throughout the reservoir. Pilot water injection trials began in 2012, and large-scale water injection development was implemented by the end of 2014. Due to the high-permeability layer, the water cut in the wells increased rapidly after water injection, reaching a total water cut of 65.9%. Thirty-three wells had a water cut exceeding 80%, while the geological recovery rate was only 13.2%. The reservoir's overall development was characterized by high water cut and low recovery, presenting significant potential for profile control and water shutoff.

[0052] Taking the implementation well group as an example, the production well AD1-7-3H in this well group experienced water breakthrough after about two years of water injection development. After water breakthrough, the water cut quickly climbed to 80% and remained high, and the oil production decreased. Figure 3 and Figure 4 As shown. Figure 5 , Comprehensive analysis of dynamic and static geological reservoir data shows that the water in this well is injected water breaking through the deep layer, and the high water content seriously suppresses oil production, the recovery rate is not high, the water plugging operation has a clear goal and huge potential. Figure 6 From the MHI analysis ranking of water flooding effect within the well group, AD1-7-3H is the oil well with the worst water injection development effect and is suitable as a water plugging target well.

[0053] The horizontal section of the AD1-7-3H well is 801 meters long and was completed using a screen. Due to the same problem of poor wellbore reentry, its production profile cannot be directly obtained through production profile testing. By interpreting the uneven industrial profile of the horizontal well, it is found that its water production section corresponds to the well section corresponding to the high-deep layer, which is 9.4 meters long. This section is the target well section to be plugged. The remaining 791.6 meters of the horizontal section is the well section that requires temporary plugging protection during water plugging. The AD1-7-3H well information and set parameter list (see Table 1) are substituted into the above formula to calculate the chemical dosage. The calculation process is shown in Equations (5), (6), and (7).

[0054] Table 1 Calculation data table of embodiment

[0055]

[0056]

[0057] Substituting the parameters in Table 1 into equations (2), (3) and (4), we obtain equations (5), (6) and (7) for the following calculation process.

[0058] Temporary plugging agent dosage Q prot calculate:

[0059]

[0060] Main plugging slug dosage Q main calculate:

[0061] Q main =(3.14×(60 2 -20 2 )+2×9.4*(60-20)×0.71×0.23×(1-0.35)=560(square)(6)

[0062] Strong plugging slug dosage Q strong calculate:

[0063] Qstrong＝ (3.14×0.0762 2 +2×9.4×20)×0.71*0.23*(1-0.35)=173 (square) (7).

[0064] The present invention also discloses an electronic device, comprising at least one processor and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the method for calculating the dosage of water plugging and profile control agents in a horizontal well pattern in a heterogeneous oil reservoir.

[0065] The present invention also discloses a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the method for calculating the dosage of a water plugging and profile control agent for a horizontal well pattern in a heterogeneous oil reservoir is implemented.

[0066] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

[0067] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A method for calculating the dosage of water plugging and profile control agents for horizontal well patterns in heterogeneous oil reservoirs, characterized in that: The method comprises the following steps: Step 1: Taking the injection-production wells where the injected water flows along the high permeability layer as the target, determine the type of injected water breakthrough and whether it is caused by reservoir heterogeneity; Step 2: Determine the length L of the well section that needs temporary plugging protection and the length L of the well section that needs deep plugging. hm ; Step 3: Calculate the temporary plugging agent dosage Q prot ; Step 4: Calculate the amount of plugging agent.

2. The method for calculating the dosage of water plugging and profile control agents for horizontal well patterns in heterogeneous oil reservoirs according to claim 1, characterized in that: When selecting an injection-production well where the injected water flows along a high permeability layer, if the injection-production well has profile monitoring results, the profile monitoring results are used in combination with the corresponding formation physical properties to determine whether the injection-production well is an injection-production well where the injected water flows along a high permeability layer.

3. The method for calculating the dosage of water plugging and profile control agents for horizontal well patterns in heterogeneous oil reservoirs according to claim 1, characterized in that: When selecting an injection-production well where the injected water flows along a high permeability layer, if there is no profile monitoring result for the injection-production well, the number of peaks of the tracer curve of the injection well is used to determine whether the injection-production well is an injection-production well where the injected water flows along a high permeability layer.

4. The method for calculating the dosage of water plugging and profile control agents for horizontal well patterns in heterogeneous oil reservoirs according to claim 1, wherein: In step 1, the primary controlling factor of injection water breakthrough is first determined, and then it is determined whether the injection water breakthrough of the production well is caused by reservoir heterogeneity. If it is determined that the injection water breakthrough of the oil well is caused by reservoir heterogeneity, a water flooding MHI analysis is performed on the production wells in the injection-production well group to screen out oil wells with poor water flooding effects and high potential for measures.

5. The method for calculating the dosage of water plugging and profile control agents for horizontal well patterns in heterogeneous oil reservoirs according to claim 4, characterized in that: Dynamic and static models, production performance, injection-production pressure response and water drive characteristic curves were used to determine the main controlling factors of injected water breakthrough, and it was determined that the injected water breakthrough in production wells was caused by reservoir heterogeneity.

6. The method for calculating the dosage of water plugging and profile control agents for horizontal well patterns in heterogeneous oil reservoirs according to claim 1, characterized in that: Determine the length L of the well section that needs temporary plugging protection and the length L of the well section that needs deep plugging hm ,include: For oil and water wells with injection and production profiles, the length L of the well section that needs temporary plugging protection and the length L of the well section that needs deep plugging are determined based on the injection and production profile test results. hm ; For oil and water wells that cannot be profile tested, the length of the well section that needs temporary plugging protection L and the length of the well section that needs deep adjustment and deep plugging L are determined by using the irregular production profile model interpretation results of the well test. hm .

7. The method for calculating the dosage of water plugging and profile control agents for horizontal well patterns in heterogeneous oil reservoirs according to claim 1, characterized in that: In step 3, the temporary plugging agent dosage Q prot The calculation formula is shown in the following formula (2); In formula (2), Q prot is the dosage of temporary plugging protective agent, in kilograms; k is the thickness of the temporary plugging agent, in kilograms / square meter; L is the length of the horizontal well section, in meters; r is the radius of the horizontal well section, in meters; c is the effective concentration of the temporary plugging agent, in kilograms / cubic meter.

8. The method for calculating the dosage of water plugging and profile control agents for horizontal well patterns in heterogeneous oil reservoirs according to claim 1, characterized in that: The plugging agent dosage includes the main plugging segment dosage Q main The amount of strong plugging segment Q strong .

9. An electronic device, characterized in that: It includes at least one processor and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the method for calculating the dosage of water plugging and profile control agents in a horizontal well pattern in a heterogeneous oil reservoir as described in any one of claims 1 to 8.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method for calculating the dosage of water plugging and profile control agents in a horizontal well pattern in a heterogeneous oil reservoir according to any one of claims 1 to 8 is implemented.

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