Numerical simulation prediction method for well cementation injection and replacement overflow and related equipment

Abstract

The invention relates to the technical field of oil and gas development drilling and completion operation well cementation, and discloses a numerical simulation and prediction method and related equipment for well cementation injection and replacement overflow leakage amount, and the method comprises the following steps: determining well cementation parameters; establishing a well cementation simulation model based on the well cementation parameters, and performing simulation analysis on the outlet flow and the wellhead pump pressure in the well cementation process in the well cementation simulation model to obtain an analysis result; calculating according to the analysis result to obtain the volume of more or less return of the outlet slurry at different times; an error is obtained through calculation of the volume of the more or less return of the outlet slurry at different times and the volume of the more or less return of the actual outlet slurry during construction, and numerical simulation prediction of the well cementation injection and replacement overflow leakage amount is conducted according to the size of the error; according to the method, the well cementation parameters are determined, and the well cementation simulation model is established based on the parameters, so that the physical process and conditions in the actual well cementation operation can be reflected more accurately, the outlet flow and the wellhead pump pressure in the well cementation process are simulated and analyzed, and the accuracy of overflow prediction is improved.

Description

Technical Field

[0001] This invention relates to the field of cementing technology in drilling and completion operations for oil and gas development, specifically to a numerical simulation prediction method and related equipment for cementing displacement leakage. Background Technology

[0002] In cementing operations with large-diameter casing in certain wells, situations often arise where the density of the cement slurry is significantly greater than that of the drilling fluid. During cementing and displacement, the pressure difference between the cement slurry and drilling fluid dynamically changes due to the density difference. When the pressure difference between the hydrostatic column inside the casing and the annulus is sufficient to overcome the pressure drop caused by fluid friction within the casing and annulus, a vacuum section appears at the wellhead. At this point, the actual outlet flow rate of the fluid in the well is greater than the pumped inflow rate. This phenomenon persists for a period of time until the cement slurry returns from the casing and enters the annulus. At this point, the actual outlet flow rate gradually decreases until it is less than the pumped inflow rate, a phenomenon commonly referred to as the "U"-shaped pipe effect. This phenomenon is normal during cementing; however, the sudden increase or decrease in outlet flow rate is a direct indication of overflow or leakage. The occurrence of the "U"-shaped pipe effect poses a significant challenge to the timely and accurate assessment of wellbore leakage during cementing operations and impacts the adjustment of cementing parameters to improve displacement efficiency.

[0003] Currently, most methods for predicting wellbore overflow rely on experience and real-time monitoring data. These methods suffer from low prediction accuracy and limited real-time performance, making them unsuitable for providing precise guidance during on-site operations. Furthermore, there is a lack of effective means to distinguish between "false overflows / false wellbore leaks" caused by the "U"-shaped pipe effect and genuine wellbore overflows / leaks at cementing sites. Therefore, accurately predicting the changing trend of the outlet flow rate and the volume of the returned slurry before cementing operations is crucial for guiding the work and accurately assessing the extent of cementing overflow. Summary of the Invention

[0004] The purpose of this invention is to provide a numerical simulation prediction method and related equipment for cementing displacement leakage, so as to solve the technical problem of inaccurate wellbore leakage prediction in the prior art.

[0005] This invention is achieved through the following technical solution: In a first aspect, the present invention provides a numerical simulation prediction method for cementing displacement leakage, comprising: Determine cementing parameters; A cementing simulation model was established based on cementing parameters. The outlet flow rate and wellhead pump pressure during the cementing process were simulated and analyzed within the cementing simulation model, and the analysis results were obtained. The volume of slurry that was returned more or less at different times was calculated based on the analysis results; The error is calculated by comparing the volume of slurry that is more or less returned at different times with the actual volume of slurry that is more or less returned at the outlet during construction. Based on the magnitude of the error, numerical simulation is used to predict the overflow volume of cementing and displacing.

[0006] Preferably, in the step of determining cementing parameters, the cementing parameters include the density of the separator fluid, the density of the cement slurry, the density of the intermediate drilling fluid, the cementing displacement volume, the cementing injection and drainage volume, the in-pipe hydrostatic pressure, and the annular hydrostatic pressure.

[0007] Furthermore, in the step of simulating and analyzing the outlet flow rate and wellhead pump pressure during the cementing process within the cementing simulation model, the wellbore structure data, drilling fluid parameters, cementing slurry data, and cementing displacement parameters are input into the cementing simulation model to simulate the cementing construction parameters and obtain the outlet flow rate, pumping pressure, and wellbore pressure distribution.

[0008] Furthermore, in the step of calculating the volume of slurry that is more or less returned at different times based on the analysis results, the theoretical volume of slurry that is more or less returned at different times is calculated based on the numerical simulation results, cementing displacement rate, and time parameters. The specific expression is as follows:

[0009] In the formula: V' is the theoretical volume of slurry that will return more or less at the outlet, in m³; Q' is the simulated outlet flow rate, in m³ / min; Q is the inlet pump discharge rate, in m³ / min; and t is the time, in min.

[0010] Furthermore, the formula for calculating the volume of slurry returned more or less at different times also includes the following:

[0011] In the formula: The pressure difference between the inside and outside of the casing when all the cement slurry is inside the casing during the cementing process, in MPa; The density of cement paste is expressed in g / cm³. 3 ; Density of drilling fluid, g / cm³ 3 ; The unit volume of the casing is expressed in L / m.

[0012] Furthermore, the pressure difference between the inside and outside of the casing when all the cement slurry is inside the casing during the cementing process is calculated based on the pressure difference between the inside and outside of the casing when all the cement slurry is inside the casing during the cementing operation. The specific formula is as follows:

[0013] In the formula: The pressure difference between the inside and outside of the casing when all the cement slurry is inside the casing during the cementing process, in MPa; The pressure of the hydrostatic column inside the pipe, in MPa; ρ is the annular hydrostatic pressure, MPa.

[0014] Preferably, the error is calculated by comparing the volume of slurry returned more or less at different times with the actual volume of slurry returned more or less at the outlet during construction, as expressed below:

[0015] In the formula, V' represents the theoretical amount of slurry that is returned more or less at the outlet; V represents the actual amount of slurry that is returned more or less at the outlet.

[0016] Preferably, the specific process of numerical simulation prediction of cementing displacement leakage based on the magnitude of the error is as follows: Set an error range. When the error is within the range, the wellbore is in a stable state; otherwise, the wellbore is overflowing or leaking.

[0017] Secondly, the present invention also provides a numerical simulation prediction system for cementing displacement leakage, comprising: The parameter determination module is used to determine cementing parameters; The model analysis module is used to establish a cementing simulation model based on cementing parameters, and to simulate and analyze the outlet flow rate and wellhead pump pressure during the cementing process within the cementing simulation model to obtain analysis results. The calculation module calculates the volume of slurry that is returned more or less at different times based on the analysis results. The prediction module calculates the error by comparing the volume of slurry that is more or less returned at different times with the actual volume of slurry that is more or less returned at the outlet during construction. Based on the magnitude of the error, it performs numerical simulation prediction of the cementing displacement leakage volume.

[0018] Thirdly, the present invention also provides a mobile terminal, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the numerical simulation prediction method for cementing displacement leakage as described above.

[0019] Fourthly, the present invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the numerical simulation prediction method for cementing displacement leakage as described above.

[0020] Fifthly, the present invention also provides a computer program product, including computer instructions, which instruct a computing device to perform operations corresponding to the numerical simulation prediction method for cementing displacement leakage as described above.

[0021] Compared with the prior art, the present invention has the following beneficial technical effects: This invention provides a numerical simulation prediction method for cementing displacement leakage. The method involves determining cementing parameters; establishing a cementing simulation model based on these parameters; simulating and analyzing the outlet flow rate and wellhead pump pressure during the cementing process within the simulation model; obtaining analysis results; calculating the volume of excess or insufficient return of outlet slurry at different times based on the analysis results; calculating the error between the excess or insufficient return volume of outlet slurry at different times and the actual excess or insufficient return volume during construction; and using the magnitude of the error to numerically predict the cementing displacement leakage. This invention, by determining cementing parameters and establishing a cementing simulation model based on these parameters, can more accurately reflect the physical processes and conditions in actual cementing operations. Simulating and analyzing the outlet flow rate and wellhead pump pressure during the cementing process within the simulation model yields more realistic analysis results, thereby improving the accuracy of leakage prediction.

[0022] Furthermore, through numerical simulation prediction, potential leaks can be anticipated before construction, allowing for the implementation of preventative measures and reducing risks during construction.

[0023] Furthermore, based on the simulation analysis results, the volume of slurry returning more or less at different times can be calculated, which helps construction personnel to more precisely control the slurry flow rate during the cementing process. By comparing the simulation prediction results with the actual construction conditions, construction parameters can be further optimized to improve the quality and efficiency of cementing operations. Attached Figure Description

[0024] Figure 1 This is a flowchart of the numerical simulation prediction method for cementing displacement leakage in an embodiment of the present invention; Figure 2 This is a schematic diagram of the numerical simulation and prediction system for cementing displacement leakage in an embodiment of the present invention; Figure 3 This is a schematic diagram of the cementing numerical simulation model in an embodiment of the present invention; Figure 4 This is a schematic diagram of the cementing displacement animation simulation of the target well in an embodiment of the present invention; Figure 5 This is a schematic diagram of the inlet and outlet flow rate change curves obtained by software simulation during the cementing process in an embodiment of the present invention; Figure 6 This is a schematic diagram of the pumping pressure change curve obtained by software simulation during the cementing process in an embodiment of the present invention; In the diagram: 1. Parameter determination module; 2. Model analysis module; 3. Calculation module; 4. Prediction module. Detailed Implementation To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0025] The present invention will now be described in further detail with reference to the accompanying drawings: The purpose of this invention is to provide a numerical simulation prediction method and related equipment for cementing displacement leakage, so as to solve the technical problem of inaccurate wellbore leakage prediction in the prior art.

[0026] See Figure 1 This invention provides a numerical simulation prediction method for cementing displacement leakage, comprising: Step 1, determine cementing parameters; Specifically, the cementing parameters include the density of the separator fluid, the density of the cement slurry, the density of the intermediate drilling fluid, the cementing displacement volume, the cementing injection and drainage volume, the hydrostatic pressure in the tubing, and the hydrostatic pressure in the annulus.

[0027] Step 2: Establish a cementing simulation model based on cementing parameters, and simulate and analyze the outlet flow rate and wellhead pump pressure during the cementing process within the cementing simulation model to obtain the analysis results; Specifically, in the step of simulating and analyzing the outlet flow rate and wellhead pump pressure during the cementing process within the cementing simulation model, the wellbore structure data, drilling fluid parameters, cementing slurry data, and cementing displacement parameters are input into the cementing simulation model to simulate the cementing construction parameters, thereby obtaining the outlet flow rate, pumping pressure, and wellbore pressure distribution. The specific analysis process is as follows: S1, Input the data required for the cementing simulation model: Wellbore structure data: including well depth, well diameter, casing specifications, well inclination angle, etc., which are the basis for building the model.

[0028] Drilling fluid parameters, such as density, viscosity, and shear stress, have a significant impact on the fluid dynamics during cementing.

[0029] Cementing slurry data includes the density, rheological parameters (such as plastic viscosity and yield stress), and setting time of the cement slurry. These data determine the flow and solidification characteristics of the cement slurry in the wellbore.

[0030] Cementing displacement parameters, such as displacement rate, displacement volume, and displacement pressure, directly affect the effectiveness and safety of cementing operations.

[0031] S2, simulate cementing construction parameters: Using the input data, the cementing process is simulated in a cementing simulation model. This includes the injection of cement slurry, the displacement of drilling fluid, and the fluid dynamics throughout the process.

[0032] During the simulation, the model calculates and outputs key parameters such as outlet flow rate, pump injection pressure, and pressure distribution within the wellbore.

[0033] S3, Analyze the results and optimize the parameters: Based on the simulation results, the rationality of the outlet flow rate, pump injection pressure, and wellbore pressure distribution is analyzed.

[0034] If the simulation results are found to be inconsistent with expectations or to have potential problems, the input parameters can be adjusted and the simulation can be repeated to optimize the cementing construction plan.

[0035] In this embodiment, the cementing simulation model is established based on numerical simulation technology, capable of simulating complex fluid dynamics. By solving the fluid dynamics equations, the model can calculate key parameters such as outlet flow rate, pumping pressure, and wellbore pressure distribution during the cementing process. The relative motion between the cement slurry and drilling fluid is crucial in the simulation. The model considers mass diffusion and momentum exchange between the cement slurry and drilling fluid, and is based on two-phase flow theory. During the simulation, the model considers pressure balance and flow resistance within the wellbore, as well as factors including hydrostatic pressure, flow resistance, and friction within the casing and annulus.

[0036] Step 3: Calculate the volume of slurry that is returned more or less at different times based on the analysis results; Specifically, in the step of calculating the volume of slurry that is more or less returned at different times based on the analysis results, the theoretical volume of slurry that is more or less returned at different times is calculated based on the numerical simulation results, cementing displacement rate, and time parameters. The specific expression is as follows:

[0037] In the formula: V' is the theoretical volume of slurry that will return more or less at the outlet, in m³; Q' is the simulated outlet flow rate, in m³ / min; Q is the inlet pump discharge rate, in m³ / min; and t is the time, in min.

[0038] Specifically, the formula for calculating the amount of slurry returned more or less at different times in this embodiment also includes the following:

[0039] In the formula: The pressure difference between the inside and outside of the casing when all the cement slurry is inside the casing during the cementing process, in MPa; The density of cement paste is expressed in g / cm³.3 ; Density of drilling fluid, g / cm³ 3 ; The unit volume of the casing is expressed in L / m.

[0040] The pressure difference between the inside and outside of the casing when all the cement slurry is inside the casing during the cementing process is calculated based on the pressure difference between the inside and outside of the casing when all the cement slurry is inside the casing during the cementing operation. The specific formula is as follows:

[0041] In the formula: The pressure difference between the inside and outside of the casing when all the cement slurry is inside the casing during the cementing process, in MPa; The pressure of the hydrostatic column inside the pipe, in MPa; ρ is the annular hydrostatic pressure, MPa.

[0042] Step 4: The error is calculated by comparing the volume of slurry returned more or less at different times with the actual volume of slurry returned more or less at the outlet during construction. Based on the magnitude of the error, numerical simulation is performed to predict the overflow of cementing and injection.

[0043] Specifically, the error is calculated by comparing the volume of slurry returned more or less at different times with the actual volume of slurry returned more or less at the outlet during construction. The expression is as follows:

[0044] In the formula, V' represents the theoretical amount of slurry that is returned more or less at the outlet; V represents the actual amount of slurry that is returned more or less at the outlet.

[0045] Specifically, the numerical simulation prediction of cementing displacement leakage based on the magnitude of the error is as follows: Set an error range. When the error is within the range, the wellbore is in a stable state; otherwise, the wellbore is overflowing or leaking.

[0046] Example 1 This embodiment 1 is based on numerical simulation research, and establishes a wellbore model as follows: Figure 3 and Figure 4 This embodiment 1 provides an evaluation formula applicable to field practice for calculating the wellbore return volume during cementing. It can also assist in judging the wellbore leakage status during cementing. The specific process is as follows: (The text then goes on to describe a method for calculating wellbore return volume during cementing, which is not directly related to the previous sentence.) Step S1: Establish a numerical simulation model for cementing the target well. Using specialized cementing software, input wellbore structure data, drilling fluid and cementing slurry data, cementing displacement parameters, etc., to simulate cementing construction parameters and obtain outlet flow rate, pump injection pressure, wellbore pressure distribution, etc.

[0047] Step S2: Quantitatively calculate and analyze cementing parameters Based on the construction parameters obtained from numerical simulation, the dynamic liquid level change of the surface mud tank, i.e. the change trend of the volume of returned mud during the cementing process, is calculated.

[0048] like Figure 5 The figure shows the predicted outlet flow rate under this model. As can be seen from the figure, during the cement grout pumping process, the outlet flow rate is greater than the pumping discharge rate. At this time, more grout is returned than pumped grout, with the excess return volume being [missing data]. Figure 5 The shaded area on the left side; during the cementing and displacement of drilling fluid, if the outlet flow rate is less than the pump injection flow rate, a phenomenon occurs where the returned slurry is less than the pumped slurry, with the short returned volume being [missing value]. Figure 5 The shaded area on the right side of the center; under conditions of no overflow or leakage in the wellbore, the volume of slurry returned in excess and in deficiency should be the same. With the above data, combined with real-time cementing parameter acquisition, the wellbore leakage status during the cementing process can be accurately determined.

[0049] like Figure 6 The figure shows the predicted pumping pressure under this model. As can be seen from the figure, there is a long period of time during cementing when the pumping pressure is 0. This is a normal phenomenon caused by the density difference between the cement slurry and the drilling fluid, and it cannot be used as a basis for judging wellbore leakage.

[0050] Step S3: Real-time monitoring of relevant parameters during the cementing process By monitoring pump pressure, outlet flow rate, and returned slurry volume in real time during the cementing process and comparing them with the above-mentioned predicted values, the leakage status of the wellbore can be determined relatively accurately.

[0051] In this embodiment, the formula for calculating the wellbore injection return volume during the injection displacement process also includes the following: Based on the cementing design, obtain the circulating pressure P1 under the circulating displacement Q; Based on the cementing design, the pressure difference between the inside and outside of the casing is calculated when all the cement slurry is inside the casing during the operation, using the following formula:

[0052] In the formula: The pressure difference between the inside and outside of the casing when all the cement slurry is inside the casing during the cementing process, in MPa; The pressure of the hydrostatic column inside the pipe, in MPa; The annular hydrostatic pressure is MPa. Step S3: Based on the cementing design, the volume of excess grout returned at the outlet and the volume of insufficient grout returned during the grout replacement process can be calculated using the following formula:

[0053] In the formula: The pressure difference between the inside and outside of the casing when all the cement slurry is inside the casing during the cementing process, in MPa; The density of cement paste is expressed in g / cm³. 3 ; Density of drilling fluid, g / cm³ 3 ; The unit volume of the casing is expressed in L / m. In this embodiment, during the cement injection process, the amount of grout returned from the outlet in the early stage is greater than V', and during the later grout replacement process, the amount of grout returned from the outlet will be less than the corresponding volume V'.

[0054] In summary, this invention provides a numerical simulation prediction method for cementing displacement leakage. The method involves determining cementing parameters; establishing a cementing simulation model based on these parameters; simulating and analyzing the outlet flow rate and wellhead pump pressure during the cementing process within the simulation model to obtain analysis results; calculating the volume of excess or insufficient outlet slurry return at different times based on the analysis results; calculating the error between the excess or insufficient outlet slurry return volume at different times and the actual excess or insufficient outlet slurry return volume during construction; and using the magnitude of the error to numerically predict the cementing displacement leakage. This invention, by determining cementing parameters and establishing a cementing simulation model based on these parameters, can more accurately reflect the physical processes and conditions in actual cementing operations. Simulating and analyzing the outlet flow rate and wellhead pump pressure during the cementing process within the simulation model yields more realistic analysis results, thereby improving the accuracy of leakage prediction.

[0055] This invention can predict the changing trend of the outlet flow rate during cementing and displacement processes and accurately calculate the volume of the injected slurry at different stages. Through precise prediction, wellbore leakage can be accurately assessed, providing strong guidance for on-site cementing operations and avoiding potential hazards caused by misjudging downhole conditions. The implementation of this invention will help improve the safety and efficiency of cementing operations and promote the sustainable development of the oil and gas development industry.

[0056] Example 2 according to Figure 2 As shown, the present invention also provides a numerical simulation prediction system for cementing displacement leakage, comprising: Parameter determination module 1 is used to determine cementing parameters; Model analysis module 2 is used to establish a cementing simulation model based on cementing parameters, and to simulate and analyze the outlet flow rate and wellhead pump pressure during the cementing process within the cementing simulation model to obtain analysis results; Calculation module 3 calculates the volume of slurry that is returned more or less at different times based on the analysis results; Prediction module 4 calculates the error by comparing the volume of slurry that is more or less returned at different times with the actual volume of slurry that is more or less returned at the outlet during construction, and then performs numerical simulation prediction of the cementing displacement leakage based on the magnitude of the error.

[0057] Example 3 The present invention also provides a mobile terminal, including a memory, a processor, and a computer program stored in the memory and executable on the processor, such as a numerical simulation prediction program for cementing displacement leakage.

[0058] When the processor executes the computer program, it implements the steps of the numerical simulation prediction method for the above-mentioned cementing displacement leakage, for example: Determine cementing parameters; A cementing simulation model was established based on cementing parameters. The outlet flow rate and wellhead pump pressure during the cementing process were simulated and analyzed within the cementing simulation model, and the analysis results were obtained. The volume of slurry that was returned more or less at different times was calculated based on the analysis results; The error is calculated by comparing the volume of slurry that is more or less returned at different times with the actual volume of slurry that is more or less returned at the outlet during construction. Based on the magnitude of the error, numerical simulation is used to predict the overflow volume of cementing and displacing.

[0059] Alternatively, when the processor executes the computer program, it implements the functions of each module in the above system, for example: Parameter determination module 1 is used to determine cementing parameters; Model analysis module 2 is used to establish a cementing simulation model based on cementing parameters, and to simulate and analyze the outlet flow rate and wellhead pump pressure during the cementing process within the cementing simulation model to obtain analysis results; Calculation module 3 calculates the volume of slurry that is returned more or less at different times based on the analysis results; Prediction module 4 calculates the error by comparing the volume of slurry that is more or less returned at different times with the actual volume of slurry that is more or less returned at the outlet during construction, and then performs numerical simulation prediction of the cementing displacement leakage based on the magnitude of the error.

[0060] For example, the computer program may be divided into one or more modules / units, which are stored in the memory and executed by the processor to complete the present invention. The one or more modules / units may be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program in the mobile terminal.

[0061] For example, the computer program can be divided into a parameter determination module 1, a model analysis module 2, a calculation module 3, and a prediction module 4; The specific functions of each module are as follows: Parameter determination module 1 is used to determine cementing parameters; Model analysis module 2 is used to establish a cementing simulation model based on cementing parameters, and to simulate and analyze the outlet flow rate and wellhead pump pressure during the cementing process within the cementing simulation model to obtain analysis results; Calculation module 3 calculates the volume of slurry that is returned more or less at different times based on the analysis results; Prediction module 4 calculates the error by comparing the volume of slurry that is more or less returned at different times with the actual volume of slurry that is more or less returned at the outlet during construction, and then performs numerical simulation prediction of the cementing displacement leakage based on the magnitude of the error.

[0062] The mobile terminal can be a computing device such as a desktop computer, laptop, handheld computer, or cloud server. The mobile terminal may include, but is not limited to, a processor and memory.

[0063] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor. The processor is the control center of the mobile terminal, connecting various parts of the mobile terminal via various interfaces and lines.

[0064] The memory can be used to store the computer program and / or module. The processor implements various functions of the mobile terminal by running or executing the computer program and / or module stored in the memory and calling the data stored in the memory.

[0065] The memory may primarily include a program storage area and a data storage area. The program storage area may store the operating system and at least one application program required for a function (such as sound playback, image playback, etc.); the data storage area may store data created based on the use of the mobile phone (such as audio data, phonebook, etc.). Furthermore, the memory may include high-speed random access memory, and may also include non-volatile memory, such as hard disks, RAM, plug-in hard disks, SmartMediaCards (SMC), Secure Digital (SD) cards, FlashCards, at least one disk storage device, flash memory device, or other volatile solid-state storage devices.

[0066] Example 4 The present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the numerical simulation prediction method for cementing displacement leakage.

[0067] If the modules / units integrated in the mobile terminal are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium.

[0068] Based on this understanding, all or part of the processes in the above method can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium. When executed by a processor, the computer program can implement the steps of the above-described aggregated reinforcement learning resource scheduling method. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or some intermediate form.

[0069] The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording media, USB flash drive, portable hard drive, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal, and software distribution medium, etc.

[0070] It should be noted that the content contained in the computer-readable medium may be appropriately added to or subtracted from the content as required by the legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable medium may not include electrical carrier signals and telecommunication signals.

[0071] Example 5 A computer program product includes computer instructions that instruct a computing device to perform operations corresponding to the numerical simulation prediction method for cementing displacement leakage as described above.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A numerical simulation prediction method for cementing displacement leakage, characterized in that, include: Determine cementing parameters; A cementing simulation model was established based on cementing parameters. The outlet flow rate and wellhead pump pressure during the cementing process were simulated and analyzed within the cementing simulation model, and the analysis results were obtained. The volume of slurry that was returned more or less at different times was calculated based on the analysis results; The error is calculated by comparing the volume of slurry that is more or less returned at different times with the actual volume of slurry that is more or less returned at the outlet during construction. Based on the magnitude of the error, numerical simulation is used to predict the overflow volume of cementing and displacing.

2. The numerical simulation prediction method for cementing displacement leakage according to claim 1, characterized in that, In the step of determining cementing parameters, the cementing parameters include the density of the isolation fluid, the density of the cement slurry, the density of the intermediate drilling fluid, the cementing displacement volume, the cementing injection and drainage volume, the hydrostatic pressure in the tubing, and the hydrostatic pressure in the annulus.

3. The numerical simulation prediction method for cementing displacement leakage according to claim 2, characterized in that, In the step of simulating and analyzing the outlet flow rate and wellhead pump pressure during the cementing process in the cementing simulation model, the wellbore structure data, drilling fluid parameters, cementing slurry data and cementing displacement parameters are input into the cementing simulation model to simulate the cementing construction parameters and obtain the outlet flow rate, pumping pressure and wellbore pressure distribution.

4. The numerical simulation prediction method for cementing displacement leakage according to claim 3, characterized in that, In the step of calculating the volume of slurry that is more or less returned at different times based on the analysis results, the theoretical volume of slurry that is more or less returned at different times is calculated based on the numerical simulation results, cementing displacement rate, and time parameters. The specific expression is as follows: In the formula: V' is the theoretical volume of slurry that will return more or less at the outlet, in m³; Q' is the simulated outlet flow rate, in m³ / min; Q is the inlet pump discharge rate, in m³ / min; and t is the time, in min.

5. The numerical simulation prediction method for cementing displacement leakage according to claim 2, characterized in that, The formula for calculating the volume of slurry that is returned more or less at different times also includes the following: In the formula: The pressure difference between the inside and outside of the casing when all the cement slurry is inside the casing during the cementing process, in MPa; The density of cement paste is expressed in g / cm³. 3 ; Density of drilling fluid, g / cm³ 3 ; The unit volume of the casing is expressed in L / m.

6. The numerical simulation prediction method for cementing displacement leakage according to claim 5, characterized in that, The pressure difference between the inside and outside of the casing when all the cement slurry is inside the casing during the cementing process is calculated based on the pressure difference between the inside and outside of the casing when all the cement slurry is inside the casing during the cementing operation. The specific formula is as follows: In the formula: The pressure difference between the inside and outside of the casing when all the cement slurry is inside the casing during the cementing process, in MPa; The pressure of the hydrostatic column inside the pipe, in MPa; ρ is the annular hydrostatic pressure, MPa.

7. The numerical simulation prediction method for cementing displacement leakage according to claim 1, characterized in that, The error is calculated by comparing the volume of slurry returned more or less at different times with the actual volume of slurry returned more or less at the outlet during construction. The expression is as follows: In the formula, V' represents the theoretical amount of slurry that is returned more or less at the outlet; V represents the actual amount of slurry that is returned more or less at the outlet.

8. The numerical simulation prediction method for cementing displacement leakage according to claim 1, characterized in that, The specific process for numerical simulation prediction of cementing displacement leakage based on the magnitude of the error is as follows: Set an error range. When the error is within the range, the wellbore is in a stable state; otherwise, the wellbore is overflowing or leaking.

9. A numerical simulation and prediction system for cementing displacement leakage, characterized in that, include: The parameter determination module is used to determine cementing parameters; The model analysis module is used to establish a cementing simulation model based on cementing parameters, and to simulate and analyze the outlet flow rate and wellhead pump pressure during the cementing process within the cementing simulation model to obtain analysis results. The calculation module calculates the volume of slurry that is returned more or less at different times based on the analysis results. The prediction module calculates the error by comparing the volume of slurry that is more or less returned at different times with the actual volume of slurry that is more or less returned at the outlet during construction. Based on the magnitude of the error, it performs numerical simulation prediction of the cementing displacement leakage volume.

10. A mobile terminal, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the numerical simulation prediction method for cementing displacement leakage as described in any one of claims 1-8.

11. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the numerical simulation prediction method for cementing displacement leakage as described in any one of claims 1-8.

12. A computer program product comprising computer instructions, characterized in that, The computer instructions instruct the computing device to perform the operation corresponding to the numerical simulation prediction method for cementing displacement leakage as described in any one of claims 1-8.

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