Casing protection method and related equipment for fire drive oil production

Abstract

This invention discloses a casing protection method and related equipment for fire-driven oil production. The method relates to the field of oil reservoir development and primarily addresses the problem of casing damage during fire-driven oil production. The method comprises: obtaining the current gas injection rate of a target injection well when the gas injection process ends; and reducing the gas injection rate in steps based on the current gas injection rate of the target injection well until the gas injection rate falls below a preset value. The present invention is applicable to the casing protection process during fire-driven oil production.

Description

Technical Field

[0001] The present invention relates to the field of oil reservoir exploitation, and in particular to a casing protection method for fire drive oil production and related equipment. Background Art

[0002] Fire flooding, also known as burning the oil layer, is a thermal oil recovery method that generates heat within the oil layer. It refers to the continuous injection of oxygen-containing media from a well, which reacts with the crude oil in the formation to produce heat and gas, driving the crude oil in the formation to flow to the production well and be produced. After years of tracking and analysis, it was found that many wells are prone to casing damage after operation, and the frequency of this situation is much higher than that of other development methods. The preliminary analysis of the reasons for this situation is mainly as follows: First, it is due to the gas injection well itself. The existing old wells with huff and puff are in poor wellbore condition after multiple rounds of steam injection; second, long-term oxygen corrosion and acid corrosion have led to a decrease in the rigidity of the casing; third, the gas injection pressure reduction technology is not standardized: At the current stage, well control requirements require pressure relief before fire flooding operations. After the gas injection is stopped, the gas injection stop valve is cut off and the casing is directly vented. In this case, the instantaneous bottomhole pressure difference is too large, and the instantaneous stress release is bound to cause certain damage to the casing body. Summary of the Invention

[0003] In view of the above problems, the present invention provides a casing protection method and related equipment for fire drive oil production, the main purpose of which is to solve the problem that the casing is easily damaged during fire drive oil production.

[0004] To solve at least one of the above technical problems, in a first aspect, the present invention provides a casing protection method for fire flooding oil production, the method comprising:

[0005] When entering the end of the gas injection process, obtain the current gas injection volume of the target injection well;

[0006] Based on the current gas injection rate of the target injection well, the gas injection rate is reduced step by step until the gas injection rate is lower than the preset value.

[0007] Optionally, the above method further includes:

[0008] When the gas injection volume is zero, obtaining the downhole pressure value of the target injection well;

[0009] The downhole pressure is controlled to decrease in a step-by-step manner based on the downhole pressure value.

[0010] Optionally, the above method further includes:

[0011] Real-time monitoring of the downhole pressure value of the target injection well;

[0012] As the downhole pressure value of the target injection well decreases in a step-by-step manner, the opening of the pressure relief nozzle of the target injection well is adjusted.

[0013] Optionally, the opening of the pressure relief nozzle is inversely proportional to the downhole pressure.

[0014] Optionally, the stepwise reduction of the gas injection rate based on the current gas injection rate of the target injection well until the gas injection rate is lower than a preset value includes:

[0015] Determining at least two step values ​​based on the current gas injection rate of the target injection well;

[0016] Under the condition that the gas injection rate of the target injection well is controlled to decrease to the target step value, monitoring the real-time flow rate value of the target injection well;

[0017] When the difference between the real-time flow rate value and the target step value is less than or equal to the preset flow rate difference, the gas injection rate of the target injection well continues to be reduced.

[0018] Optionally, the above method further includes:

[0019] Obtain the estimated useful life of the casing of the target injection well;

[0020] The number of the above-mentioned step values ​​is determined based on the expected service life of the casing of the above-mentioned target injection well.

[0021] Optionally, the above method further includes:

[0022] The estimated service life is determined based on the service life of the casing, the soil characteristics and climate characteristics of the target injection well.

[0023] In a second aspect, an embodiment of the present invention further provides a casing protection device for fire flooding oil production, comprising:

[0024] An acquisition unit, configured to acquire the current gas injection volume of the target injection well when the gas injection process is ended;

[0025] The reducing unit is used to reduce the gas injection rate in a step-by-step manner based on the current gas injection rate of the above-mentioned target injection well until the gas injection rate is lower than a preset value.

[0026] To achieve the above object, according to a third aspect of the present invention, a computer-readable storage medium is provided, wherein the computer-readable storage medium includes a stored program, wherein when the program is executed by a processor, the steps of the casing protection method for fire flooding oil production are implemented.

[0027] To achieve the above-mentioned object, according to a fourth aspect of the present invention, there is provided an electronic device comprising at least one processor and at least one memory connected to the processor; wherein the processor is configured to call program instructions in the memory to execute the steps of the above-mentioned casing protection method for fire flooding oil production.

[0028] Through the above-mentioned technical solution, the present invention provides a casing protection method and related equipment for fire-driven oil production. This method addresses the problem of casing being easily damaged during fire-driven oil production by obtaining the current gas injection volume of the target injection well when the gas injection process ends; then, based on the current gas injection volume of the target injection well, the gas injection volume is reduced in a stepwise manner until it falls below a preset value. In this solution, the stepwise reduction of the gas injection volume can eliminate the impact of the hydraulic agitation caused by the suction effect at the moment of well shut-in on the perforation section, providing strong on-site operability, standardizing the technical details of fire-driven operations, and reducing the incidence of casing damage caused by improper human operation methods.

[0029] Correspondingly, the casing protection device, equipment, and computer-readable storage medium for fire flooding oil production provided by the embodiments of the present invention also have the above-mentioned technical effects.

[0030] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are specifically listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. The same reference symbols are used throughout the drawings to represent the same components. In the drawings:

[0032] Figure 1 A schematic flow chart of a casing protection method for fire flooding oil production provided by an embodiment of the present invention is shown;

[0033] Figure 2 A schematic block diagram of the components of a casing protection device for fire flooding oil production provided by an embodiment of the present invention is shown;

[0034] Figure 3 A schematic block diagram of the components of an electronic device for casing protection in fire flooding oil production provided by an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0035] Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0036] In order to solve the problem that the casing is easily damaged during fire drive oil production, the embodiment of the present invention provides a casing protection method for fire drive oil production, such as Figure 1 As shown, the method includes:

[0037] S101, when entering the end of the gas injection process, obtaining the current gas injection volume of the target injection well;

[0038] For example, since fire drive development is based on the original well network and the well network is replanned, in order to reduce investment and improve economic benefits, old wells are usually used as secondary development well networks after stratum adjustment during fire drive development. Maintaining the integrity of the well network during fire drive development is a fundamental project for the effectiveness of fire drive development. The integrity of the well network directly affects the degree of planar effectiveness of fire drive and indirectly affects the level of fire drive development. In practice, as the development of the fire drive well network deepens, the well conditions need to be regularly inspected to verify whether the well conditions are complete. The current main method is to shut down the wells for inspection, that is, to inspect the tubing string of fire drive gas injection wells. The purpose is to check the downhole technical conditions of gas injection wells with large cumulative injection volumes or long injection times. After tracking and analysis of this plan, it was found that many wells suffered casing damage after operation. The frequency of this situation is much higher than that of other development methods. The location of the casing damage is mostly located near the upper part of the perforation section, which manifests as dislocation and diameter reduction.

[0039] For example, in this solution, when entering the end of the gas injection process, the current gas injection volume of the target injection well is obtained, and the next processing strategy is determined based on this data.

[0040] S102 , based on the current gas injection rate of the target injection well, reducing the gas injection rate in a stepwise manner until the gas injection rate is lower than a preset value.

[0041] For example, when entering the end of the gas injection process and executing the pipe inspection operation instruction plan, this scheme first determines the downward adjustment level of the "step reduction" based on the normal injection volume and wellhead pressure of the well, and uses the electric regulating valve based on the flow meter to make its flow meet the requirements of the plan after the reduction.

[0042] For example, if the normal injection well is 12,000 cubic meters per day, take 3,000 as a step level, and gradually reduce the volume in stages before shutting down the well, from 12,000 to 9,000, to 6,000, to 3,000, until the main valve is completely shut down; the operation interval is maintained at more than 10 minutes to 30 minutes.

[0043] If the normal injection volume of the injection well is 10,000 cubic meters per day, take 2,500 as a step level, and gradually reduce the volume in stages before shutting down the well, from 10,000 to 7,500 to 5,000 to 2,500, and finally completely shut down the trunk valve;

[0044] If the normal injection volume of the injection well is 8,000 cubic meters per day, take 2,000 as a step, and gradually reduce the volume in stages before shutting down the well, from 8,000 to 6,000 to 4,000 to 2,000, and finally completely shut down the main valve;

[0045] It is understood that if the injection rate of the injection well is greater than 12,000 cubic meters per day or less than 8,000 cubic meters per day, the magnitude of the step-down rate can be flexibly defined according to the above principles. The time interval in the above method is mainly based on the time required for pressure to stabilize after the step-down rate during the field test and can be flexibly set.

[0046] Through the above technical solution, the present invention provides a casing protection method for fire-driven oil production. This method addresses the problem of casing being easily damaged during fire-driven oil production. The present invention obtains the current gas injection volume of the target injection well when the gas injection process ends; based on the current gas injection volume of the target injection well, the gas injection volume is reduced in a stepwise manner until the gas injection volume falls below a preset value. In this solution, the stepwise reduction of the gas injection volume can eliminate the impact of the hydraulic agitation caused by the suction effect at the moment of well shut-in on the perforation section. It has strong on-site operability, standardizes the technical details of fire-driven operations, and reduces the incidence of casing damage caused by improper human operation methods.

[0047] In one embodiment, the method further includes:

[0048] When the gas injection volume is zero, obtaining the downhole pressure value of the target injection well;

[0049] The downhole pressure is controlled to decrease in a step-by-step manner based on the downhole pressure value.

[0050] For example, the original fire drive pressure reduction method before the inspection column is to instantaneously close the gas injection valve in front of the regulating valve before the gas injection well needs to be operated, and open the production gate at the wellhead. The gas in the formation flows out in the reverse direction through the wellbore and is emptied or connected to a natural gas station for treatment until the pressure returns to zero. Due to the instantaneous closure of the stop valve and the opening of the production gate to vent and reduce the pressure, the drastic pressure fluctuation causes an excessively large instantaneous pressure difference inside and outside the casing near the perforation section. Calculated at a well depth of 1000 meters, ignoring the gas column pressure, the pressure difference inside and outside the casing of the wellbore perforation section is also 6MPa when the dry pressure is 6MPa. The instantaneous stress release is bound to cause certain damage to the casing body.

[0051] After completing the well shut-in operation, this plan enters the "graded control" pressure release operation phase.

[0052] For example, if the oil pressure of the injection well is 6MPa after shutting in, the pressure is controlled in stages from 6MPa to 4MPa, to 2MPa, to less than 0.5MPa, and so on, until the pressure is released below 0.5MPa.

[0053] If the oil pressure in the injection well is 4MPa after shut-in, the pressure will be controlled in stages from 4MPa to 3MPa, then to 2MPa, then to less than 0.5MPa, and so on, until the pressure is below 0.5MPa.

[0054] It is understood that if the oil pressure is greater than 6 MPa or less than 4 MPa, the magnitude of "graded control" can be flexibly defined according to the above principles. This method can eliminate the impact of hydraulic agitation caused by suction effects such as those at the moment of well shut-in on the perforation section.

[0055] In one embodiment, the method further includes:

[0056] Real-time monitoring of the downhole pressure value of the target injection well;

[0057] As the downhole pressure value of the target injection well decreases in a step-by-step manner, the opening of the pressure relief nozzle of the target injection well is adjusted.

[0058] For example, by simultaneously controlling the pressure drop and nozzle opening in a stepped manner, the system ensures that the pressure does not drop too quickly, potentially causing suction and casing deformation upon shutting in. For example, during the "staged control" pressure release phase, if the injection well's oil pressure is at 6 MPa after shutting in, the staged pressure control decreases from 6 MPa to 4 MPa, then to 2 MPa, and finally to less than 0.5 MPa. The corresponding nozzles are installed, increasing in size one level at a time, with each 2 MPa drop in pressure followed by the next nozzle opening, and so on, until the pressure is below 0.5 MPa.

[0059] If the oil pressure of the injection well is 4MPa after shutting in, the pressure is controlled in stages from 4MPa to 3MPa, 2MPa, and less than 0.5MPa. Install 6mm, 8mm, and 10mm nozzles to enlarge them in sequence. For every 1MPa drop in pressure, increase the nozzle level, and so on, until the pressure is below 0.5MPa.

[0060] It can be understood that if the pressure is greater than 6 MPa or less than 4 MPa, the magnitude of “graded control” can be flexibly defined according to the above principles.

[0061] In one embodiment, the opening of the pressure relief nozzle is inversely proportional to the downhole pressure.

[0062] The principle followed in this scheme is that when the pressure is higher, the nozzle of the spray nozzle is smaller, and vice versa.

[0063] For example, after shutting in a well, observe the wellhead oil pressure and perform pressure relief. In field practice, shut-in oil pressure is typically less than 6 MPa. Initially, a 4mm nozzle is used. When the pressure drops to 4 MPa, the nozzle is enlarged to the next level, 6 mm. When the pressure drops to 2 MPa, the nozzle is enlarged to the next level, 8 mm. Once the oil pressure drops below 0.5 MPa, the nozzle is removed and the well is drained directly, preventing casing damage caused by rapid changes in downhole pressure.

[0064] In one embodiment, the stepwise reduction of the gas injection rate based on the current gas injection rate of the target injection well until the gas injection rate is lower than a preset value includes:

[0065] Determining at least two step values ​​based on the current gas injection rate of the target injection well;

[0066] Under the condition that the gas injection rate of the target injection well is controlled to decrease to the target step value, monitoring the real-time flow rate value of the target injection well;

[0067] When the difference between the real-time flow rate value and the target step value is less than or equal to the preset flow rate difference, the gas injection rate of the target injection well continues to be reduced.

[0068] For example, assuming that the preset flow difference is 100 cubic meters, such as 10,000 cubic meters of gas are injected per day, the first step of reducing the gas volume is executed to 8,000 cubic meters. When the current real-time flow value is between 7,950 and 8,050 cubic meters, it proves that the pressure is stable. At this time, the next step of reducing the volume to 6,000 is executed. This step can usually achieve pressure stability after 10 to 30 minutes. Repeat this operation by analogy until the well is shut in, thereby preventing the situation where the real-time flow value in the target injection well has not reached the target step value when it drops to the target step value, and the next step of reducing the gas injection volume is immediately carried out, resulting in too fast a reduction in the gas injection volume and damage to the casing.

[0069] In one embodiment, the method further includes:

[0070] Obtain the estimated useful life of the casing of the target injection well;

[0071] The number of the above-mentioned step values ​​is determined based on the expected service life of the casing of the above-mentioned target injection well.

[0072] For example, this solution automatically estimates the expected service life of the target injection well casing. If the expected service life is longer, it proves that the casing quality is better, and the step value can be appropriately reduced. If the expected service life is shorter, the casing quality is poor, and the number of step values ​​is increased to control the slow decrease of domestic gas injection volume and pressure, and prevent casing damage caused by excessively rapid changes in downhole pressure.

[0073] In one embodiment, the method further includes:

[0074] The estimated service life is determined based on the service life of the casing, the soil characteristics and climate characteristics of the target injection well.

[0075] Exemplarily, the expected service life of the casing of this scheme is the comprehensive service life of the casing, and the area where the target injection well is located is obtained, and the expected service life is estimated by the soil characteristics and climate characteristics of the target injection well area. For example, the longer the service life of the casing, the shorter the expected service life. If the soil characteristics of the target injection well are acidic soil, the casing will be corroded. If the climate characteristics are large temperature differences, the expected service life of the casing will be shorter. This is used to comprehensively judge the expected service life of the above-mentioned casing.

[0076] For example, the technical route of stop-injection-depressurization proposed in this plan defines the technical points for implementing stop-injection-depressurization, and forms a depressurization method before the inspection string operation, namely "step-by-step reduction" before stopping injection and "graded control" during depressurization. This can eliminate the impact of hydraulic agitation caused by the suction effect at the moment of shut-in on the perforation section, reduce the incidence of casing damage accidents caused by improper human operation methods, maintain the integrity of the fire drive well network, and maximize the service life of the well.

[0077] Furthermore, as a response to the above Figure 1 In order to realize the method shown in the figure, the embodiment of the present invention also provides a casing protection device for fire drive oil production, which is used for the above Figure 1 This device embodiment corresponds to the aforementioned method embodiment. For ease of reading, this device embodiment will not describe the details of the aforementioned method embodiment one by one, but it should be clear that the device in this embodiment can implement all the contents of the aforementioned method embodiment. Figure 2 As shown, the device includes: an acquisition unit 21, a reduction unit 22, wherein

[0078] An acquisition unit 21 is used to acquire the current gas injection volume of the target injection well when the gas injection process ends;

[0079] The reducing unit 22 is used to reduce the gas injection rate in a step-by-step manner based on the current gas injection rate of the target injection well until the gas injection rate is lower than a preset value.

[0080] Exemplarily, the above unit is further used for:

[0081] When the gas injection volume is zero, obtaining the downhole pressure value of the target injection well;

[0082] The downhole pressure is controlled to decrease in a step-by-step manner based on the downhole pressure value.

[0083] Exemplarily, the above unit is further used for:

[0084] Real-time monitoring of the downhole pressure value of the target injection well;

[0085] As the downhole pressure value of the target injection well decreases in a step-by-step manner, the opening of the pressure relief nozzle of the target injection well is adjusted.

[0086] Exemplarily, the opening of the pressure relief nozzle is inversely proportional to the downhole pressure.

[0087] Exemplarily, the stepwise reduction of the gas injection rate based on the current gas injection rate of the target injection well until the gas injection rate is lower than a preset value includes:

[0088] Determining at least two step values ​​based on the current gas injection rate of the target injection well;

[0089] Under the condition that the gas injection rate of the target injection well is controlled to decrease to the target step value, monitoring the real-time flow rate value of the target injection well;

[0090] When the difference between the real-time flow rate value and the target step value is less than or equal to the preset flow rate difference, the gas injection rate of the target injection well continues to be reduced.

[0091] Exemplarily, the above unit is further used for:

[0092] Obtain the estimated useful life of the casing of the target injection well;

[0093] The number of the above-mentioned step values ​​is determined based on the expected service life of the casing of the above-mentioned target injection well.

[0094] Exemplarily, the above unit is further used for:

[0095] The estimated service life is determined based on the service life of the casing, the soil characteristics and climate characteristics of the target injection well.

[0096] Through the above technical solution, the casing protection device for fire-driven oil production provided by the present invention addresses the problem of casing being easily damaged during fire-driven oil production. The present invention obtains the current gas injection volume of the target injection well when the gas injection process ends; based on the current gas injection volume of the target injection well, the gas injection volume is reduced in steps until the gas injection volume falls below a preset value. In this solution, the step-by-step reduction of the gas injection volume can eliminate the impact of the hydraulic agitation caused by the suction effect at the moment of well shut-in on the perforation section, has strong on-site operability, standardizes the technical details of fire-driven operations, and reduces the incidence of casing damage caused by improper human operation methods.

[0097] The processor includes a core, which retrieves the corresponding program unit from the memory. One or more cores can be configured, and by adjusting core parameters, a casing protection method for fire flooding oil production is implemented, which can solve the problem of casing being easily damaged during fire flooding oil production.

[0098] An embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium includes a stored program, and when the program is executed by a processor, the casing protection method for fire flooding oil production is implemented.

[0099] An embodiment of the present invention provides a processor, which is used to run a program, wherein the program executes the casing protection method for fire flooding oil production when running.

[0100] An embodiment of the present invention provides an electronic device, comprising at least one processor and at least one memory connected to the processor; wherein the processor is configured to call program instructions in the memory to execute the above-mentioned casing protection method for fire drive oil production.

[0101] An embodiment of the present invention provides an electronic device 30, such as Figure 3 As shown, the electronic device includes at least one processor 301, at least one memory 302 connected to the processor, and a bus 303; wherein the processor 301 and the memory 302 communicate with each other via the bus 303; the processor 301 is used to call program instructions in the memory to execute the above-mentioned casing protection method for fire flooding oil production.

[0102] The intelligent electronic devices in this article can be PCs, PADs, mobile phones, etc.

[0103] The present application also provides a computer program product, which, when executed on a process management electronic device, is adapted to execute a program for initializing the following method steps:

[0104] When entering the end of the gas injection process, obtain the current gas injection volume of the target injection well;

[0105] Based on the current gas injection rate of the target injection well, the gas injection rate is reduced step by step until the gas injection rate is lower than the preset value.

[0106] Furthermore, the above method also includes:

[0107] When the gas injection volume is zero, obtaining the downhole pressure value of the target injection well;

[0108] The downhole pressure is controlled to decrease in a step-by-step manner based on the downhole pressure value.

[0109] Furthermore, the above method also includes:

[0110] Real-time monitoring of the downhole pressure value of the target injection well;

[0111] As the downhole pressure value of the target injection well decreases in a step-by-step manner, the opening of the pressure relief nozzle of the target injection well is adjusted.

[0112] Furthermore, the opening of the pressure relief nozzle is inversely proportional to the downhole pressure.

[0113] Furthermore, the stepwise reduction of the gas injection rate based on the current gas injection rate of the target injection well until the gas injection rate is lower than a preset value includes:

[0114] Determining at least two step values ​​based on the current gas injection rate of the target injection well;

[0115] Under the condition that the gas injection rate of the target injection well is controlled to decrease to the target step value, monitoring the real-time flow rate value of the target injection well;

[0116] When the difference between the real-time flow rate value and the target step value is less than or equal to the preset flow rate difference, the gas injection rate of the target injection well continues to be reduced.

[0117] Furthermore, the above method also includes:

[0118] Obtain the estimated useful life of the casing of the target injection well;

[0119] The number of the above-mentioned step values ​​is determined based on the expected service life of the casing of the above-mentioned target injection well.

[0120] Furthermore, the above method also includes:

[0121] The estimated service life is determined based on the service life of the casing, the soil characteristics and climate characteristics of the target injection well.

[0122] It should be noted that, in the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0123] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0124] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded computer, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0125] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0126] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 The steps for the function specified in one or more boxes.

[0127] The present application also provides a computer program product, which includes computer software instructions. When the computer software instructions are executed on a processing device, the processing device is caused to execute the following Figure 1 This corresponds to the flow of memory control in the embodiment.

[0128] A computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function according to the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium can be any available medium that a computer can store or a data storage device such as a server or data center that includes one or more available media integrated. The available medium can be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid state drive (SSD)).

[0129] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0130] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of units is only a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interface, device or unit, which can be electrical, mechanical or other forms.

[0131] Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0132] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0133] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0134] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A casing protection method for fire flooding oil production, characterized in that: include: When entering the end of the gas injection process, obtain the current gas injection volume of the target injection well; reducing the gas injection rate in a stepwise manner based on the current gas injection rate of the target injection well until the gas injection rate is lower than a preset value; The stepwise reduction of the gas injection rate based on the current gas injection rate of the target injection well until the gas injection rate is lower than a preset value includes: Determining at least two step values ​​based on the current gas injection rate of the target injection well; Under the condition that the gas injection rate of the target injection well is controlled to decrease to a target step value, monitoring the real-time flow rate value of the target injection well; When the difference between the real-time flow rate value and the target step value is less than or equal to the preset flow rate difference, continue to reduce the gas injection rate of the target injection well; Obtaining an estimated service life of the casing of the target injection well; The number of the target step values ​​is determined based on an expected service life of the casing of the target injection well.

2. The method according to claim 1, characterized in that Also includes: When the gas injection volume is zero, obtaining the downhole pressure value of the target injection well; The downhole pressure is controlled to decrease in a step-by-step manner based on the downhole pressure value.

3. The method according to claim 2, characterized in that Also includes: Real-time monitoring of the downhole pressure of the target injection well; As the downhole pressure value of the target injection well decreases in a stepwise manner, the opening of the pressure relief nozzle of the target injection well is adjusted.

4. The method according to claim 3, characterized in that The opening of the pressure relief nozzle is in inverse proportion to the downhole pressure.

5. The method according to claim 1, wherein Also includes: The expected service life is determined based on the service life of the casing, soil characteristics and climate characteristics of the target injection well.

6. A casing protection device for fire flooding oil production, characterized in that: An acquisition unit, configured to acquire the current gas injection volume of the target injection well when the gas injection process is ended; a reducing unit, configured to reduce the gas injection rate in a stepwise manner based on the current gas injection rate of the target injection well until the gas injection rate is lower than a preset value; The stepwise reduction of the gas injection rate based on the current gas injection rate of the target injection well until the gas injection rate is lower than a preset value includes: Determining at least two step values ​​based on the current gas injection rate of the target injection well; Under the condition that the gas injection rate of the target injection well is controlled to decrease to a target step value, monitoring the real-time flow rate value of the target injection well; When the difference between the real-time flow rate value and the target step value is less than or equal to the preset flow rate difference, continue to reduce the gas injection rate of the target injection well; Obtaining an estimated service life of the casing of the target injection well; The number of the target step values ​​is determined based on an expected service life of the casing of the target injection well.

7. A computer-readable storage medium, characterized in that The computer-readable storage medium includes a stored program, wherein when the program is executed by a processor, the steps of the casing protection method for fire flooding oil production according to any one of claims 1 to 5 are implemented.

8. An electronic device, characterized in that: The electronic device includes at least one processor and at least one memory connected to the processor; wherein the processor is used to call program instructions in the memory to execute the steps of the casing protection method for fire flooding oil production according to any one of claims 1 to 5.

Images