Cement paste injection method, device, equipment, medium and product

Abstract

The embodiment of the invention provides a cement paste injection method, device and equipment, a medium and a product, and relates to the technical field of petroleum engineering well cementation. According to the method, in the cement paste injection process, the density and mechanical property parameters of injected cement paste are continuously obtained, and whether the cement paste adapts to the stratum mechanical environment of the current well section and the fracturing dynamic load expected to bear or not is judged. And when it is detected that the parameters deviate from the preset range, the density and mechanical parameters of the cement paste are adjusted immediately, and it is ensured that the newly injected cement paste can meet the alternating stress possibly borne by the well section in the follow-up production process and the heterogeneous formation influence. According to the closed-loop control mechanism based on real-time feedback, the adaptability of cement paste and the structural integrity and interface sealing performance of the cement sheath under the dynamic load are improved, the problems of cement sheath body damage and micro annular space expansion caused by parameter mismatching are avoided, and the limitation that a traditional static empirical value is difficult to deal with complex geological conditions is overcome.

Description

Technical Field

[0001] The present application relates to the technical field of petroleum engineering cementing, and in particular to a cement slurry injection method, device, equipment, medium and product. Background Art

[0002] Cementing is the process of injecting cement slurry into the annular space between the wellbore casing and the formation, which solidifies to form a cement sheath. To achieve a high-quality cement sheath, scientific cement slurry injection is crucial. Precise design is required to ensure that the cement slurry fully fills the annular space in the downhole environment while preventing pressure imbalances that could lead to leakage or gas channeling. This is crucial to successful cementing.

[0003] In the existing technology, cement slurry injection usually adopts the segmented injection method. First, the wellbore is divided into several sections through downhole graded cementing tools. Then, cement slurry with different performance parameters is injected into the annulus of each section in sequence according to the designed sequence. The pump injection volume and pressure are precisely controlled to ensure that each section of cement slurry fully fills the target annulus area. Finally, it is allowed to solidify to form a segmented continuous cement ring structure.

[0004] However, existing technologies suffer from low cement slurry adaptability. The staged injection process lacks adaptive design for the dynamic loads of fracturing. Cement slurry performance parameters rely on static empirical values, which are difficult to adapt to dynamic alternating loads and the differentiated mechanical environment of heterogeneous formations. This results in the cement sheath being susceptible to bulk cracking and expansion of interfacial micro-annular gaps under the alternating stresses of fracturing. Summary of the Invention

[0005] The embodiments of the present application provide a cement slurry injection method, device, equipment, medium and product to solve the problem of low adaptability of cement slurry in the prior art.

[0006] In a first aspect, an embodiment of the present application provides a cement slurry injection method, comprising:

[0007] Obtaining a target injection height; wherein the target injection height includes a plurality of unit heights;

[0008] Injecting a first cement slurry into a preset injection area; wherein the first cement slurry is a cement slurry having a density of a preset first density and mechanical parameters of a preset first mechanical parameter, wherein the first mechanical parameter is used to indicate the structural integrity of a first cement sheath formed by the first cement slurry;

[0009] In response to the first cement slurry having been injected to a first height, the first density being within a preset cement slurry density range, and the first mechanical parameter being within a preset mechanical value range, injecting the first cement slurry into the injection area; wherein the first height is less than the target injection height, and the first height includes a plurality of unit heights;

[0010] In response to the first cement slurry having been injected to the first height, the first density is outside the cement slurry density range, or the first mechanical parameter is outside the mechanical value range, adjusting the first density or the first mechanical parameter to obtain a second density and a second mechanical parameter; wherein the second density is within the cement slurry density range, and the second mechanical parameter is within the mechanical value range;

[0011] injecting a second cement slurry into the injection area; wherein the second cement slurry is a cement slurry having a density of the second density and mechanical parameters of the second mechanical parameters;

[0012] In response to the second cement slurry being injected to the target injection height, the injection is stopped.

[0013] In a second aspect, an embodiment of the present application provides a cement slurry injection device, the device comprising:

[0014] A first acquisition module is configured to acquire a target injection height; wherein the target injection height includes a plurality of unit heights;

[0015] a first injection module, configured to inject a first cement slurry into a preset injection area; wherein the first cement slurry is a cement slurry having a density of a preset first density and mechanical parameters of preset first mechanical parameters, wherein the first mechanical parameters are used to indicate the structural integrity of a first cement annulus formed by the first cement slurry;

[0016] a second injection module, configured to inject the first cement slurry into the injection area in response to the first cement slurry having been injected to a first height, the first density being within a preset cement slurry density range, and the first mechanical parameter being within a preset mechanical value range; wherein the first height is less than the target injection height, and the first height includes a plurality of unit heights;

[0017] an adjustment module, configured to adjust the first density or the first mechanical parameter to obtain a second density and a second mechanical parameter in response to the first cement slurry having been injected to the first height and the first density being outside the cement slurry density range or the first mechanical parameter being outside the mechanical value range; wherein the second density is within the cement slurry density range and the second mechanical parameter is within the mechanical value range;

[0018] a third injection module, configured to inject a second cement slurry into the injection area; wherein the second cement slurry is a cement slurry having a density of the second density and mechanical parameters of the second mechanical parameters;

[0019] The injection stopping module is configured to stop injection in response to the second cement slurry being injected to the target injection height.

[0020] In a third aspect, the present application provides an electronic device, comprising: a processor, and a memory communicatively connected to the processor;

[0021] The memory stores computer-executable instructions;

[0022] When the processor executes the computer-executable instructions stored in the memory, it is used to implement the cement slurry injection method as described in any one of the first aspects.

[0023] In a fourth aspect, the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions, and when the computer-executable instructions are executed by a processor, they are used to implement the cement slurry injection method as described in any one of the first aspects.

[0024] In a fifth aspect, the present application provides a computer program product, comprising a computer program, which, when executed by a processor, is used to implement the cement slurry injection method as described in any one of the first aspects.

[0025] The present application provides a cement slurry injection method, device, equipment, medium and product. During the cement slurry injection process, the density and mechanical property parameters of the injected cement slurry are continuously obtained to determine whether it is adapted to the formation mechanical environment of the current well section and the expected fracturing dynamic load. When it is detected that the parameters deviate from the preset range, the density and mechanical parameters of the cement slurry are immediately adjusted to ensure that the newly injected cement slurry can meet the alternating stress and heterogeneous formation influence that the well section may be subjected to during subsequent production. This closed-loop control mechanism based on real-time feedback improves the adaptability of the cement slurry and the structural integrity and interface sealing of the cement sheath under dynamic loads, avoids the problems of cement sheath body damage and micro-annulus expansion caused by parameter mismatch, and overcomes the limitations of traditional static empirical values ​​that are difficult to cope with complex geological conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0027] Figure 1 A schematic diagram of an application scenario of the cement slurry injection method provided in an embodiment of the present application;

[0028] Figure 2 Schematic diagram of the cement slurry injection method provided in this embodiment Figure 1 ;

[0029] Figure 3 Schematic diagram of the cement slurry injection method provided in this embodiment Figure 2 ;

[0030] Figure 4 A schematic diagram of a casing-cement sheath-formation assembly model provided in an embodiment of the present application;

[0031] Figure 5 A schematic structural diagram of a cement slurry injection device provided in an embodiment of the present application;

[0032] Figure 6 A schematic diagram of the hardware structure of an electronic device provided in an embodiment of the present application.

[0033] The above drawings illustrate specific embodiments of the present application, which will be described in more detail below. These drawings and the textual description are not intended to limit the scope of the present application in any way, but rather to illustrate the concepts of the present application to those skilled in the art by reference to specific embodiments. DETAILED DESCRIPTION

[0034] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0035] In the embodiments of the present application, words such as "first" and "second" are used to distinguish between identical or similar items with substantially the same functions and effects. Those skilled in the art will understand that words such as "first" and "second" do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit differences. It should be noted that in the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described in this application as "exemplary" or "for example" should not be interpreted as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a concrete way. In the embodiments of the present application, "at least one" refers to one or more, and "more" refers to two or more.

[0036] It should be noted that the phrase "at the time of..." in the embodiments of this application can refer to the instantaneous occurrence of a certain situation or a period of time after the occurrence of a certain situation, and this is not specifically limited in this embodiment of this application. Furthermore, the cement slurry injection method, device, equipment, medium, and product provided in the embodiments of this application are merely examples, and a cement slurry injection method, device, equipment, medium, and product may also include more or less content.

[0037] The technical solution of the present invention is described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present invention will be described below with reference to the accompanying drawings.

[0038] The following introduces the application scenarios of the cement slurry injection method provided in the embodiments of the present application. Figure 1 Schematic diagram of the application scenario of the cement slurry injection method provided in the embodiment of the present application. Figure 1 As shown, the application scenario includes a mobile terminal 101 and a server 102, and the server 102 includes a controller 1021 and an actuator 1022. The mobile terminal 101 obtains a target injection height and sends the target injection height to the controller 1021. The controller 1021 controls the actuator 1022 to inject a first cement slurry into a preset injection area. In response to the first cement slurry having been injected to the first height, the first density being within the preset cement slurry density range, and the first mechanical parameter being within the preset mechanical value range, the controller 1021 controls the actuator 1022 to inject the first cement slurry into the injection area. In response to the first cement slurry having been injected to the first height, the first density being outside the cement slurry density range, or the first mechanical parameter being outside the mechanical value range, the controller 1021 adjusts the first density or the first mechanical parameter to obtain a second density and a second mechanical parameter. The controller 1021 controls the actuator 1022 to inject a second cement slurry into the injection area. In response to the second cement slurry having been injected to the target injection height, the controller 1021 stops injection.

[0039] The embodiments of the present invention are described below with reference to the accompanying drawings.

[0040] Figure 2 Schematic diagram of the cement slurry injection method provided in this embodiment Figure 1 .like Figure 2 As shown, the cement slurry injection method provided in this embodiment includes the following steps:

[0041] S201. Obtain a target injection height; wherein the target injection height includes multiple unit heights.

[0042] Specifically, the target injection height can be determined based on actual downhole conditions and sealing requirements. This step serves to define the vertical control baseline for cement slurry sealing operations, enabling subsequent dynamic adjustments to slurry performance parameters to match the differentiated geomechanical conditions at different depths.

[0043] S202. Inject a first cement slurry into a preset injection area; wherein the first cement slurry refers to a cement slurry having a density of a preset first density and mechanical parameters of preset first mechanical parameters, and the first mechanical parameters are used to indicate the structural integrity of a first cement ring formed by the first cement slurry.

[0044] Specifically, the prepared first cement slurry can be transported along the wellbore to the injection area through special grouting equipment. This step is used to ensure that the initially injected cement slurry has the preset density and mechanical properties, forming a basic sealing layer that can withstand the initial stress of the formation, and providing a benchmark condition for subsequent dynamic adjustments.

[0045] S203. In response to the first cement slurry having been injected to a first height, the first density being within a preset cement slurry density range, and the first mechanical parameter being within a preset mechanical value range, injecting the first cement slurry into the injection area; wherein the first height is less than the target injection height, and the first height includes multiple unit heights.

[0046] Specifically, the density and mechanical parameters of cement slurry can be monitored in real time. After confirming that they meet the preset standards, the first cement slurry is accurately delivered to the injection area using a segmented grouting process. This step is used to establish a basic sealing layer that matches the formation characteristics, ensuring that the initially formed cement ring can not only withstand subsequent construction loads, but also provide a benchmark reference for dynamically adjusting subsequent grouting parameters.

[0047] S204. In response to the first cement slurry having been injected to the first height, the first density is outside the cement slurry density range, or the first mechanical parameter is outside the mechanical numerical range, adjusting the first density or the first mechanical parameter to obtain a second density and a second mechanical parameter; wherein the second density is within the cement slurry density range, and the second mechanical parameter is within the mechanical numerical range.

[0048] Specifically, by real-time analysis of the cement slurry flow state and formation feedback data, when it is detected that the density or mechanical parameters deviate from the preset standards, the additive ratio and mixing process parameters can be dynamically adjusted. This step is used to generate a cement slurry with a second density and second mechanical parameters that meets the current geological conditions, ensuring that the subsequently injected slurry can both compensate for the initial grouting defects and adapt to the dynamic stress changes of the formation.

[0049] S205. Inject a second cement slurry into the injection area; wherein the second cement slurry refers to a cement slurry having a second density and second mechanical parameters.

[0050] Specifically, an optimized grouting process delivers a second cement slurry along the wellbore structure to the injection zone. This step allows for the dynamic adjustment of the new slurry mix to compensate for initial sealing defects if initial grouting parameters fall short of target, forming a secondary cement sheath adapted to formation stress variations. By comparing the flow characteristics and curing strength of the slurries before and after real-time adjustments, the subsequently injected modified slurry ensures that it not only corrects previous construction deviations but also forms a stable, integrated seal with the already injected slurry.

[0051] S206: In response to the second cement slurry having been injected to the target injection height, stop injection.

[0052] Specifically, once the cumulative injection volume has reached the preset cementing height, the pumping equipment can be immediately shut down and cement slurry injection operations terminated. This step precisely controls the final cementing quality, preventing material waste or abnormal downhole pressure caused by excessive injection. This ensures a complete and qualified cement sheath structure throughout the target well section, providing reliable stratum isolation for subsequent oil and gas production operations.

[0053] For example, after injecting a first cement slurry at a height of ΔH from the wellhead, it is determined whether the cement slurry density is within the cement slurry density window, and whether the cement sheath has tensile or compressive damage and micro-annulus. If any of the conditions is not met, the density or mechanical parameters of the first cement slurry are adjusted until all the above conditions are met at the same time, thereby obtaining a second cement slurry. The second cement slurry is then injected with ΔH as the unit length, while ensuring that the second cement slurry meets the density window and does not suffer from tensile or compressive damage and micro-annulus. If the cement slurry system fails to meet the density window or tension, compression, or microannulus occurs in a wellbore section, the simulation is stopped and the injected height is recorded, representing the height of the first cement slurry column. At this point, the density and mechanical parameters of the first cement slurry section are also determined. Once the first cement slurry column height is determined, this height is used as the starting point to adjust the cement slurry density or mechanical parameters so that, in the next section (ΔH), it simultaneously meets the density window, the bulk failure criterion, and the microannulus criterion. Continued injection and injection stop steps are then performed, and the injection height is recorded to determine the height of the second cement slurry column. The above steps are repeated for subsequent sections until the second cement slurry is injected to the target injection height, at which point injection is stopped. The value of ΔH is adjusted based on wellbore heterogeneity. It is set between 20 and 50 meters in sections with sudden formation pressure fluctuations and between 100 and 200 meters in stable formation sections. ΔH remains constant throughout a complete iteration to avoid distortion in the calculated slurry column height due to height changes. ΔH can only be adjusted after a specific cement slurry column height has been determined.

[0054] This embodiment provides a cement slurry injection method, which continuously obtains the density and mechanical property parameters of the injected cement slurry during the cement slurry injection process to determine whether it is suitable for the formation mechanical environment of the current well section and the expected fracturing dynamic load. When it is detected that the parameters deviate from the preset range, the density and mechanical parameters of the cement slurry are immediately adjusted to ensure that the newly injected cement slurry can meet the alternating stress and heterogeneous formation influence that the well section may be subjected to during subsequent production. This closed-loop control mechanism based on real-time feedback improves the adaptability of the cement slurry and the structural integrity and interface sealing of the cement sheath under dynamic loads, avoids the problems of cement sheath body damage and micro-annulus expansion caused by parameter mismatch, and overcomes the limitation of traditional static experience values ​​that are difficult to cope with complex geological conditions.

[0055] In one possible design, the multiple calculation models include a multi-layer thick-wall cylinder model, a cement sheath body failure model, and a cement sheath micro-annulus expansion model; the multiple first structural integrity data include a first radial stress, a first tangential stress, and a first micro-annulus; the multiple second structural integrity data include a second radial stress, a second tangential stress, and a second micro-annulus; S204: when the first density is outside the cement slurry density range or the first mechanical parameter is outside the mechanical value range, the first density or the first mechanical parameter is adjusted to obtain a second density and a second mechanical parameter, including:

[0056] S2041. The first density is outside the cement slurry density range, and the first mechanical parameter is within the mechanical value range. The first density is adjusted to obtain a second density, and the first mechanical parameter is determined as the second mechanical parameter.

[0057] Specifically, if only the cement slurry density does not meet the requirements but the mechanical properties meet the standards, the cement slurry density can be adjusted by changing the slurry ratio or adding a density modifier while maintaining the original mechanical properties. This step is used to specifically address the mismatch between cement slurry density and formation pressure, returning the cement slurry density to a reasonable range while ensuring that structural strength is not affected.

[0058] S2042. If the first density is within the cement slurry density range and the first mechanical parameter is outside the mechanical value range, the first mechanical parameter is adjusted to obtain a second mechanical parameter, and the first density is determined as the second density.

[0059] Specifically, if the cement slurry density meets the requirements but the mechanical properties fall short, the mechanical properties of the cement slurry can be improved by optimizing the additive ratio while maintaining the original density. This step is used to specifically enhance the structural strength and deformation capacity of the cement sheath, ensuring that the mechanical properties of the cement slurry meet the requirements for long-term sealing while ensuring that the downhole pressure balance is not affected.

[0060] S2043. The first density is outside the cement slurry density range, and the first mechanical parameter is outside the mechanical value range. The first density and the first mechanical parameter are adjusted to obtain a second density and a second mechanical parameter.

[0061] Specifically, if neither the density nor the mechanical properties of the cement slurry meet the requirements, the slurry composition can be adjusted to optimize its density and structural properties. This step improves the physical and mechanical properties of the cement slurry, ensuring that it meets both downhole pressure control requirements and structural load-bearing requirements, ensuring that the formed cement sheath effectively balances formation pressure.

[0062] The technical effect of this solution in this embodiment is: when only the density exceeds the standard, the density is adjusted separately while retaining the qualified mechanical parameters; when only the mechanical parameters exceed the standard, the mechanical properties are corrected while the compliant density is used; when both exceed the standard, the adjustment items are flexibly selected. This hierarchical processing strategy ensures that each adjustment is made to the actual defect, while minimizing unnecessary parameter changes, so that the cement slurry operates within the appropriate performance range, and improves the adaptability and reliability of the cementing operation.

[0063] Figure 3 Schematic diagram of the cement slurry injection method provided in this embodiment Figure 2 In this embodiment, Figure 2 Based on the provided embodiment, the cement slurry injection method is further explained. The cement slurry injection method includes:

[0064] S301. Acquire a plurality of first data and a plurality of second data; wherein the plurality of first data are used to represent geological properties of the injection area, and the plurality of second data are used to represent physical properties of the first cement sheath under different stress and environmental conditions.

[0065] Specifically, multiple first and second data sets can be obtained through a combination of well logging data analysis and laboratory testing. This step is used to fully understand the formation characteristics and cement material behavior in the construction area, providing a reliable basis for the subsequent scientific setting of key cement slurry parameter ranges.

[0066] S302: Calculate the cement slurry density range based on the plurality of first data.

[0067] Specifically, the geologic parameters of the target well section can be combined with empirical formulas to deduce the cement slurry density range that meets balanced sealing requirements. This step scientifically determines the specific gravity control standard for the cement slurry, ensuring it effectively balances formation pressure to prevent kicks and leaks while also ensuring a dense and stable cement sheath structure after curing, providing a reasonable density reference range for subsequent dynamic adjustments.

[0068] For example, the three-pressure profile constraint method can be used to calculate the upper and lower boundaries of cement slurry density. The calculation formula for the lower boundary of cement slurry density is:

[0069]

[0070]

[0071] in, is the lower boundary of cement slurry density, is the pore pressure, For safety additional density, is the formation pore pressure, and H is the well depth.

[0072] The upper limit of cement slurry density is calculated based on the fracture pressure, loss pressure and safety margin of the weakest formation in the open hole section, and is constrained by experimental data on cement stone compressive strength, permeability and volume stability under high temperature conditions to ensure the long-term sealing integrity of the cement sheath in high temperature environments. The calculation formula for the upper limit of cement slurry density is:

[0073]

[0074]

[0075]

[0076] in, is the upper boundary of cement slurry density, is the formation fracture pressure equivalent density, is the leakage pressure equivalent density, is the safety margin, is the burst pressure, is the lost circulation pressure, and H is the well depth.

[0077] If the measured pore pressure deviates significantly from the predicted value, the density needs to be adjusted dynamically. The calculation formula for the adjusted density is:

[0078]

[0079] in, is the adjusted density, is the design density, is the measured pressure, is the predicted pressure, k is the feedback coefficient, and H is the well depth.

[0080] when When , the correction term is positive, Increase, when When , the correction term is negative, Decrease.

[0081] Considering the actual engineering situation, it is necessary to introduce the equivalent circulating density model to dynamically control the designed density. The calculation formula for the equivalent density of the liquid column pressure actually borne by the bottom of the well is:

[0082]

[0083] in, is the equivalent density of the liquid column pressure actually borne by the bottom of the well during cement slurry circulation, is the mass of cement slurry per unit volume at rest, is the annular friction pressure loss, and H is the well depth.

[0084] The numerical range of cement slurry density when changing along the well depth gradient can be expressed as:

[0085]

[0086] Among them, Z is the density of cement slurry at different depths, Used to indicate that the density of cement slurry varies with depth.

[0087] S303. Input the plurality of second data into a plurality of preset calculation models to obtain a plurality of first structural integrity data and a plurality of second structural integrity data; wherein the plurality of first structural integrity data are used to represent the stress distribution and crack width of the first cement sheath when subjected to an external load in an assembly system comprising a casing, a first cement sheath, and a formation; and the second structural integrity data are used to quantify the inherent anti-destruction limit of the cement material and the crack width under preset stress conditions.

[0088] Specifically, the mechanical performance parameters of cement materials under different environmental conditions can be input into the multi-dimensional analysis module, and the coupling algorithm can be used to analyze the stress conduction characteristics and material strength of the first cement ring. Multiple first structural integrity data reflect the collaborative deformation characteristics of the assembly under load, and multiple second structural integrity data quantify the anti-destruction ability of the cement material under critical state.

[0089] S304: Calculate a mechanical value range based on the plurality of first structural integrity data and the plurality of second structural integrity data.

[0090] Specifically, the stress distribution characteristics of the cement sheath under downhole loads and its inherent resistance to damage can be comprehensively considered. By comparing and analyzing critical failure conditions under different operating conditions, a mechanical value range can be derived. This step is used to establish control standards for key mechanical properties of cement materials, ensuring that the cement sheath formed by the subsequently prepared cement slurry after curing has sufficient crack resistance.

[0091] S305. Obtain a target injection height; wherein the target injection height includes multiple unit heights.

[0092] S306. Injecting a first cement slurry into a preset injection area; wherein the first cement slurry refers to a cement slurry having a density of a preset first density and mechanical parameters of preset first mechanical parameters, and the first mechanical parameters are used to indicate the structural integrity of a first cement ring formed by the first cement slurry.

[0093] S307. In response to the first cement slurry having been injected to a first height, the first density being within a preset cement slurry density range, and the first mechanical parameter being within a preset mechanical value range, the first cement slurry is injected into the injection area; wherein the first height is less than the target injection height, and the first height includes multiple unit heights.

[0094] S308. In response to the first cement slurry having been injected to the first height, the first density is outside the cement slurry density range, or the first mechanical parameter is outside the mechanical numerical range, the first density or the first mechanical parameter is adjusted to obtain a second density and a second mechanical parameter; wherein the second density is within the cement slurry density range, and the second mechanical parameter is within the mechanical numerical range.

[0095] S309. Injecting a second cement slurry into the injection area; wherein the second cement slurry refers to a cement slurry having a second density and second mechanical parameters.

[0096] S310: In response to the second cement slurry being injected to the target injection height, stop injection.

[0097] S305-S310 are similar to S201-S206 and will not be described in detail in this embodiment.

[0098] The technical effect of this solution in this embodiment is that, before determining the target injection height, geological attribute data of the injection area and data on the interaction between the cement sheath and the geological structure are collected, thereby accurately calculating the cement slurry density range and mechanical value range. This method allows the cement slurry performance parameters to better match the specific geological conditions and structural interactions, fundamentally avoiding cement sheath failure caused by parameter design that is out of sync with geological conditions.

[0099] In one possible design, S302, calculating the cement slurry density range based on the plurality of first data, includes:

[0100] S3021. Calculate the upper boundary and the lower boundary of cement slurry density based on the plurality of first data.

[0101] Specifically, by analyzing key parameters such as formation pore pressure, fracture pressure, and rock stability, we can determine the minimum density required to maintain wellbore stability and the maximum density required to prevent formation fracturing. This step establishes a safe operating window for cement slurry density, ensuring that during injection, it effectively supports the wellbore and prevents collapse, while also preventing excessive density from fracturing the formation and causing losses.

[0102] S3022. Generate a cement slurry density range based on the cement slurry density upper boundary and the cement slurry density lower boundary.

[0103] Specifically, the calculated minimum and maximum density values ​​can be used as the endpoints of the interval to form a reasonable cement slurry density range for construction reference. This step is used to clarify the density control standard for cement slurry preparation, allowing subsequent injection operations to be flexibly adjusted according to actual conditions within a safe range, thereby avoiding wellbore instability caused by insufficient density and preventing formation fractures caused by excessive density.

[0104] The technical effect of this solution in this embodiment is: by analyzing geological attribute data, the upper and lower boundary values ​​of the cement slurry density are accurately calculated, and a density safety range that meets the actual formation conditions is constructed, so that the cement slurry density selection can not only ensure that the annulus is fully filled but also avoid leakage or fracturing caused by formation pressure imbalance, thereby improving the adaptability of the cement sheath in the complex stress environment of the formation.

[0105] In one possible design, the multiple calculation models include a multi-layer thick-wall cylinder model, a cement sheath body failure model, and a cement sheath micro-annulus expansion model; the multiple first structural integrity data include a first radial stress, a first tangential stress, and a first micro-annulus; and the multiple second structural integrity data include a second radial stress, a second tangential stress, and a second micro-annulus. S303: Inputting the multiple second data into the multiple preset calculation models to obtain the multiple first structural integrity data and the multiple second structural integrity data includes:

[0106] S3031. Input multiple second data into the multi-layer thick-walled cylinder model to obtain the first radial stress, the first tangential stress and the first micro-annulus; wherein the multi-layer thick-walled cylinder model is used to quantify the stress state of the plastic zone of the cement sheath and the micro-annulus failure probability, the first radial stress and the first tangential stress are used to represent the radial stress and tangential stress of the first cement sheath in the assembly system, respectively, and the first micro-annulus refers to the crack width generated when the first cement sheath is subjected to the first radial stress and the first tangential stress in the assembly system.

[0107] Specifically, parameters such as formation pressure and casing restraint can be substituted into the stress field equations for thick-walled cylinders to determine the stress distribution and deformation response of the cement sheath under combined loads. This allows the calculation of the microcrack development threshold, which characterizes interfacial debonding. This step is used to evaluate the mechanical behavior of the cement sheath in complex downhole stress environments. By quantifying the degree of radial stress concentration, tangential tensile strength margin, and potential crack expansion trends, it provides data for optimizing cement slurry mixes and grouting processes.

[0108] In the multi-layer thick-walled cylindrical model, the casing and the formation are both elastic bodies, the cement sheath is an ideal elastic-plastic body, and the yield condition satisfies the Mohr-Coulomb strength criterion:

[0109]

[0110] in, is the circumferential stress, is the radial stress, is the internal friction angle of debris, A is the calculation parameter used to determine the maximum and minimum principal stresses. When A=1, When A=-1, C is the cohesion of the cement sheath.

[0111] For cement annulus that meets the Mohr-Coulomb strength criterion, the equilibrium equation is:

[0112]

[0113] Among them, r is the radius of a certain point of the assembly, It is the outer radius of the surrounding rock of the well wall. The assembly consists of casing, cement sheath and formation.

[0114] Figure 4 Schematic diagram of the casing-cement sheath-formation assembly model provided in the embodiment of this application. Figure 4 As shown in the figure, from inside to outside, there are: casing, cement sheath plastic zone, cement sheath elastic zone and formation. The inner wall of the casing is subjected to internal pressure. The stress at the interface between the casing and the plastic zone of the cement sheath is , the stress on the elastic-plastic interface of cement sheath is , the stress on the interface between the elastic zone of cement sheath and the stratum is , the outer boundary force of the stratum is The model is used to analyze the stress transfer and elastic-plastic deformation of the casing-cement sheath-formation system under fracturing or downhole loading to evaluate wellbore integrity and microannulus expansion risk.

[0115] The calculation formula of the equivalent density of the liquid column pressure actually borne by the bottom of the joint well, as well as the numerical range and boundary conditions that the cement slurry density satisfies when it changes along the well depth gradient , When , the stress distribution expression of the plastic zone of the cement ring can be obtained as:

[0116]

[0117]

[0118]

[0119] in, is the radial stress, is the circumferential stress, C is the cement sheath cohesion, A is the calculation parameter, and B is the intermediate parameter related to the principal stress. is the pressure at the interface between casing and cement sheath, is the internal friction angle of debris, r is the radius of a certain point of the combination, is the inner radius of the cement sheath.

[0120] From this, the force expression of the elastic-plastic interface of the cement sheath can be obtained as follows:

[0121]

[0122] in, is the elastic-plastic interface stress of cement sheath, is the elastoplastic boundary of the cement sheath. Ignoring the plastic volume strain, and combining the above formula, the displacements of the inner and outer boundaries of the plastic zone of the cement sheath are:

[0123]

[0124]

[0125] in, is the radial displacement of the inner wall of the plastic zone of the cement sheath, is the radial displacement of the outer wall of the plastic zone of the cement sheath, is the Poisson's ratio of the cement sheath, is the elastic modulus of cement sheath, K is the integral constant, is the pressure at the interface between casing and cement sheath. It can be defined as:

[0126]

[0127] S3032. Input multiple second parameters into the cement sheath body failure model to obtain a second radial stress and a second tangential stress; wherein the cement sheath body failure model is used to evaluate the anti-destruction ability of the cement material, and the second radial stress and the second tangential stress are used to represent the ability of the cement material of the first cement slurry to resist radial extrusion failure and tangential extrusion failure, respectively.

[0128] Specifically, material strength parameters and confining pressure conditions can be substituted into the failure criterion equation, and combined with the elastic-plastic constitutive relationship to solve for the bearing limit of the cement sheath in a bidirectional stress field, thereby obtaining the critical stress value that represents the compressive resistance. This step is used to evaluate the structural stability of cement materials under complex downhole loading conditions. By quantifying the radial compression resistance threshold and the tangential tensile resistance threshold, it provides data support for optimizing cement formulations and ensures that a sufficiently strong sealing barrier is formed after cementing.

[0129] Among them, the cement sheath body failure model can simulate the failure behavior of the cement sheath under load, truly reflect the nonlinear behavior of the cement sheath under high stress, and identify high failure risk areas. In terms of model setting, the temperature-displacement coupling analysis step can be used to solve the cement sheath body failure model and output the radial stress and tangential stress of the cement sheath.

[0130] S3033. Input multiple second parameters into the cement sheath micro-annulus expansion model to obtain a second micro-annulus; wherein the cement sheath micro-annulus expansion model is used to quantify the width of the micro-annulus, and the second micro-annulus refers to the crack width that appears in the first cement sheath under preset stress conditions.

[0131] Specifically, by substituting parameters such as interfacial bond strength and confining stress into the crack propagation criterion equation, the crack initiation and propagation patterns in stress-concentrated areas can be analyzed, and the critical crack width, which represents the degree of interfacial debonding, can be calculated. This step is used to predict the likelihood of cement sheath failure in complex downhole stress environments. By quantifying the development and expansion trends of microcracks, it provides a scientific basis for optimizing cement slurry performance and construction processes, ensuring the formation of a long-term, stable interlayer barrier after cementing.

[0132] Among them, the cement sheath micro-annulus expansion model can simulate the peeling effect of high-pressure fluid on the cement sheath interface and quantify the micro-annulus width. The annulus width calculation formula is:

[0133]

[0134]

[0135]

[0136]

[0137] in, and are the true strain and nominal strain, and are true stress and nominal stress, respectively. 、 and are true plastic strain, true elastic strain and total strain respectively, E is elastic modulus, L is micro-annulus width, F is cement sheath thickness,

[0138] In terms of model setting, position constraints are imposed on the formation boundary, initial geostress is applied to the formation, and pressure load is applied to the inner wall of the casing. The influence of friction resistance on the internal pressure is considered. The upper limit of the cyclic internal pressure load is the sum of the wellhead pressure, the hydrostatic column pressure, and friction resistance, and the lower limit is equal to the hydrostatic column pressure. The calculation formula for the casing internal pressure is:

[0139]

[0140] Where, P is the casing internal pressure, is the wellhead pressure, is the fracturing fluid density, is a constant, H is the well depth, and f is the friction resistance.

[0141] The first radial stress and the first tangential stress are compared with the second radial stress and the second tangential stress, respectively. At the same time, the first microannulus is compared with the second microannulus. When the difference between the first radial stress and the second radial stress is less than 10% of the second radial stress, the difference between the first tangential stress and the second tangential stress is less than 10% of the second tangential stress, and the difference between the first microannulus and the second microannulus is less than 10% of the second microannulus, the average value of the first radial stress and the second radial stress is taken as the final radial stress, the average value of the first tangential stress and the second tangential stress is taken as the final tangential stress, and the average value of the first microannulus and the second microannulus is taken as the final microannulus. The calculated average radial and tangential stresses are applied to the Mohr-Coulomb strength criterion to determine the integrity of the cement sheath to avoid tensile and compressive failure. The calculated average microannulus value is compared with the experimental value to ensure that the average value is less than the experimental value to avoid the generation of microannulus during the fracturing process.

[0142] The technical effect of this solution in this embodiment is: using a thick-walled cylinder model to evaluate the overall stress distribution of the composite structure, combining it with a bulk failure model to analyze the material's inherent strength characteristics, and then using a micro-annulus expansion model to predict the likelihood of interfacial debonding, ultimately forming an integrity evaluation index that comprehensively reflects the actual operating conditions of the cement sheath. This multi-dimensional analysis method considers both the structural response under external loads and the material's inherent resistance to damage and interfacial sealing performance, providing a scientific basis for cement slurry parameter design and ensuring that the resulting cement sheath can adapt to the complex stress environment downhole.

[0143] In one possible design, the multiple calculation models include a multi-layer thick-wall cylinder model, a cement sheath body failure model, and a cement sheath micro-annulus expansion model; the multiple first structural integrity data include a first radial stress, a first tangential stress, and a first micro-annulus; and the multiple second structural integrity data include a second radial stress, a second tangential stress, and a second micro-annulus. S304: Calculating a mechanical value range based on the multiple first structural integrity data and the multiple second structural integrity data includes:

[0144] S3041. Calculate a first difference between the first radial stress and the second radial stress, a second difference between the first tangential stress and the second tangential stress, and a third difference between the first microannular gap and the second microannular gap.

[0145] Specifically, the two radial stresses representing the interface stress, the two tangential stresses representing the material's crack resistance, and the two microcrack widths reflecting the degree of crack development can be algebraically subtracted to obtain the deviation of the corresponding mechanical indicators. This step is used to verify the consistency of the model with actual working conditions. By quantifying the differences in stress distribution and the deviation in crack growth, it provides data support for adjusting grouting pressure and optimizing material ratios, ensuring a sealing structure with balanced mechanical properties after cementing.

[0146] S3042. In response to the first difference, the second difference, and the third difference being all less than a preset difference threshold, calculate a first average value of the first radial stress and the second radial stress, a second average value of the first tangential stress and the second tangential stress, and a third average value of the first microannulus and the second microannulus.

[0147] Specifically, the two radial stresses that characterize the material's compressive properties, the two tangential stresses that reflect its crack resistance, and the two microcracks that describe the interface integrity can be calculated by performing an arithmetic average. This step is used to establish cementing quality evaluation standards. By combining multiple sets of measured data with the averaged values ​​of the calculated results, the discreteness caused by measurement errors is eliminated, providing a benchmark reference value for determining the structural stability of the cement sheath.

[0148] S3043. Determine a range based on the first average value, the second average value, and the third average value to obtain a stress value range.

[0149] Specifically, a comprehensive analysis of the mean radial stress (reflecting the material's compressive properties), the mean tangential stress (characterizing crack resistance), and the mean microcrack width (describing interface integrity) can be performed to define upper and lower limits encompassing the typical fluctuation range of each parameter. This step is used to establish cementing quality acceptance criteria. By integrating the central trends and dispersion of multiple sets of mechanical indicators, a reasonable tolerance range is formed, providing a quantitative basis for determining the long-term sealing performance of the cement sheath.

[0150] The technical effect of this solution in this embodiment is: through a dual calculation verification mechanism, different mechanical models are first used to independently calculate the stress parameters, and then the consistency of the calculation results of each model is ensured by difference comparison. The average value is used as the final parameter only when the difference is within the allowable range. This cross-verification method effectively eliminates the calculation deviation that may exist in a single model, retains the advantageous characteristics of different models, and ensures the scientificity and reliability of the final mechanical parameters through threshold screening.

[0151] Figure 5 This is a schematic diagram of the structure of the cement slurry injection device provided in the embodiment of the present application. Figure 5 As shown, the cement slurry injection device comprises:

[0152] The first acquisition module 501 is used to acquire a target injection height; wherein the target injection height includes a plurality of unit heights.

[0153] The first injection module 502 is used to inject the first cement slurry into the preset injection area; wherein the first cement slurry refers to a cement slurry having a density of a preset first density and a mechanical parameter of a preset first mechanical parameter, and the first mechanical parameter is used to indicate the structural integrity of the first cement ring formed by the first cement slurry.

[0154] The second injection module 503 is used to inject the first cement slurry into the injection area in response to the first cement slurry having been injected to a first height, the first density being within a preset cement slurry density range, and the first mechanical parameter being within a preset mechanical value range; wherein the first height is less than the target injection height, and the first height includes multiple unit heights.

[0155] Adjustment module 504 is used to adjust the first density or the first mechanical parameter to obtain a second density and a second mechanical parameter in response to the first cement slurry having been injected to the first height and the first density being outside the cement slurry density range or the first mechanical parameter being outside the mechanical numerical range; wherein the second density is within the cement slurry density range and the second mechanical parameter is within the mechanical numerical range.

[0156] The third injection module 505 is used to inject the second cement slurry into the injection area; wherein the second cement slurry refers to a cement slurry having a second density and a second mechanical parameter.

[0157] The injection stopping module 506 is configured to stop injection in response to the second cement slurry being injected to the target injection height.

[0158] In one possible design, the cement slurry injection device further includes:

[0159] The second acquisition module is used to acquire a plurality of first data and a plurality of second data; wherein the plurality of first data are used to represent the geological attributes of the injection area, and the plurality of second data are used to represent the physical properties of the first cement sheath under different stress and environmental conditions.

[0160] The first calculation module is used to calculate the cement slurry density range according to the plurality of first data.

[0161] A second calculation module is used to input the plurality of second data into a plurality of preset calculation models to obtain a plurality of first structural integrity data and a plurality of second structural integrity data; wherein the plurality of first structural integrity data are used to represent the stress distribution and crack width of the first cement sheath when subjected to an external load in an assembly system comprising a casing, a first cement sheath and a formation; and the second structural integrity data are used to quantify the inherent anti-destruction limit of the cement material and the crack width under preset stress conditions.

[0162] The third calculation module is used to calculate the mechanical value range according to the plurality of first structural integrity data and the plurality of second structural integrity data.

[0163] In one possible design, the first computing module includes:

[0164] The first calculation unit is used to calculate the upper boundary of cement slurry density and the lower boundary of cement slurry density according to the plurality of first data.

[0165] The range generating unit is used to generate a cement slurry density range according to an upper boundary of cement slurry density and a lower boundary of cement slurry density.

[0166] In one possible design, the multiple calculation models include a multi-layer thick-wall cylinder model, a cement sheath body failure model, and a cement sheath micro-annulus expansion model; the multiple first structural integrity data include a first radial stress, a first tangential stress, and a first micro-annulus; the multiple second structural integrity data include a second radial stress, a second tangential stress, and a second micro-annulus; and the second calculation module includes:

[0167] The first input unit is used to input multiple second data into the multi-layer thick-walled cylinder model to obtain a first radial stress, a first tangential stress, and a first micro-annulus; wherein the multi-layer thick-walled cylinder model is used to quantify the stress state of the plastic zone of the cement sheath and the micro-annulus failure probability, the first radial stress and the first tangential stress are used to represent the radial stress and tangential stress experienced by the first cement sheath in the assembly system, respectively, and the first micro-annulus refers to the width of a crack generated when the first cement sheath is subjected to the first radial stress and the first tangential stress in the assembly system.

[0168] The second input unit is used to input multiple second parameters into the cement sheath body failure model to obtain a second radial stress and a second tangential stress; wherein the cement sheath body failure model is used to evaluate the anti-destruction ability of the cement material, and the second radial stress and the second tangential stress are used to respectively represent the ability of the cement material of the first cement slurry to resist radial extrusion failure and tangential extrusion failure.

[0169] The third input unit is used to input multiple second parameters into the cement sheath micro-annulus expansion model to obtain a second micro-annulus; wherein the cement sheath micro-annulus expansion model is used to quantify the width of the micro-annulus, and the second micro-annulus refers to the width of the crack that appears in the first cement sheath under preset stress conditions.

[0170] In one possible design, the third computing module includes:

[0171] The second calculation unit is used to calculate a first difference between the first radial stress and the second radial stress, a second difference between the first tangential stress and the second tangential stress, and a third difference between the first micro-annular gap and the second micro-annular gap.

[0172] A third calculation unit is used to calculate a first average value of the first radial stress and the second radial stress, a second average value of the first tangential stress and the second tangential stress, and a third average value of the first microannulus and the second microannulus in response to the first difference, the second difference and the third difference being less than a preset difference threshold.

[0173] The range determination unit is used to perform range determination based on the first average value, the second average value, and the third average value to obtain a stress value range.

[0174] In one possible design, the adjustment module 504 includes:

[0175] The first adjustment unit is used to adjust the first density to obtain the second density when the first density is outside the cement slurry density range and the first mechanical parameter is within the mechanical value range, and determine the first mechanical parameter as the second mechanical parameter.

[0176] The second adjustment unit is used to adjust the first mechanical parameter to obtain the second mechanical parameter when the first density is within the cement slurry density range and the first mechanical parameter is outside the mechanical value range, and determine the first density as the second density.

[0177] The third adjustment unit is used to adjust the first density and the first mechanical parameter when the first density is outside the cement slurry density range and the first mechanical parameter is outside the mechanical value range to obtain the second density and the second mechanical parameter.

[0178] The cement slurry injection device provided in this embodiment can be performed Figure 2 and Figure 3 The technical solution of the embodiment of the cement slurry injection method shown in the figure has the same implementation principle and technical effect as Figure 2 and Figure 3 The embodiment of the cement slurry injection method shown is similar and will not be described in detail here.

[0179] Figure 6 Schematic diagram of the hardware structure of the electronic device provided in the embodiment of the present application. Figure 6 As shown, the electronic device 60 includes: at least one processor 601 and a memory 602. The electronic device 60 also includes a communication component 603. The processor 601, the memory 602 and the communication component 603 are connected via a bus 604.

[0180] During the specific implementation process, at least one processor 601 executes the computer-executable instructions stored in the memory 602, so that the at least one processor 601 is used to implement a cement slurry injection method of the above embodiment.

[0181] The specific implementation process of the processor 601 can be found in the above method embodiment. Its implementation principle and technical effects are similar and will not be repeated here in this embodiment.

[0182] In the above embodiment, it should be understood that the processor 601 may be a central processing unit (CPU), or may be other general-purpose processors, digital signal processors (DSP), or application-specific integrated circuits (ASIC). The general-purpose processor may be a microprocessor or any conventional processor. The steps of the method disclosed in the present invention may be directly executed by a hardware processor or by a combination of hardware and software modules in the processor.

[0183] The memory 602 may include a high-speed RAM memory, and may also include a non-volatile storage NVM, such as at least one disk storage.

[0184] Bus 604 can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus. Bus 604 can be classified as an address bus, a data bus, a control bus, etc. For ease of illustration, the bus 604 in the drawings of this application is not limited to a single bus or a single type of bus.

[0185] The above-mentioned functions implemented by the electronic device and the main control device have introduced the solutions provided by the embodiments of the present invention. It can be understood that in order to implement the above-mentioned functions, the electronic device or the main control device includes hardware structures and / or software modules corresponding to the execution of each function. In combination with the units and algorithm steps of the various examples described in the embodiments disclosed in the embodiments of the present invention, the embodiments of the present invention can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the technical solution of the embodiments of the present invention.

[0186] The present application also provides a computer-readable storage medium storing computer-executable instructions. When executed by a processor, the computer-executable instructions implement the cement slurry injection method of the above embodiment. In the specific implementation of the above cement slurry injection method, each module can be implemented as a processor.

[0187] The readable storage medium may be implemented by any type of volatile or non-volatile memory device, or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The readable storage medium may be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0188] An exemplary readable storage medium is coupled to a processor, enabling the processor to read information from and write information to the readable storage medium. Alternatively, the readable storage medium may be an integral part of the processor. The processor and the readable storage medium may be located in an application-specific integrated circuit (ASIC). Alternatively, the processor and the readable storage medium may be present as discrete components in an electronic device or a host control device.

[0189] An embodiment of the present application further provides a computer program product, including a computer program. When the computer program is executed by a processor, it is used to implement a cement slurry injection method of the above embodiment.

[0190] The computer program is stored in a readable storage medium. At least one processor can read the computer program from the readable storage medium, and at least one processor can execute the computer program to perform the solution provided in any of the above embodiments.

[0191] Those skilled in the art will appreciate that all or part of the steps in the above-described method embodiments can be implemented using hardware associated with program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0192] So far, the technical solution of the present application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the scope of protection of the present application is obviously not limited to these specific embodiments. The above embodiments are only used to illustrate the technical solution of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solution to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A cement slurry injection method, characterized in that: include: Obtaining a target injection height; wherein the target injection height includes a plurality of unit heights; Injecting a first cement slurry into a preset injection area; wherein the first cement slurry is a cement slurry having a density of a preset first density and mechanical parameters of a preset first mechanical parameter, wherein the first mechanical parameter is used to indicate the structural integrity of a first cement sheath formed by the first cement slurry; In response to the first cement slurry having been injected to a first height, the first density being within a preset cement slurry density range, and the first mechanical parameter being within a preset mechanical value range, injecting the first cement slurry into the injection area; wherein the first height is less than the target injection height, and the first height includes a plurality of unit heights; In response to the first cement slurry having been injected to the first height, the first density is outside the cement slurry density range, or the first mechanical parameter is outside the mechanical value range, adjusting the first density or the first mechanical parameter to obtain a second density and a second mechanical parameter; wherein the second density is within the cement slurry density range, and the second mechanical parameter is within the mechanical value range; injecting a second cement slurry into the injection area; wherein the second cement slurry is a cement slurry having a density of the second density and mechanical parameters of the second mechanical parameters; In response to the second cement slurry being injected to the target injection height, the injection is stopped.

2. The cement slurry injection method according to claim 1, characterized in that: Before obtaining the target injection height, the method further includes: Acquire a plurality of first data and a plurality of second data; wherein the plurality of first data are used to represent geological attributes of the injection area, and the plurality of second data are used to represent physical properties of the first cement sheath under different stress and environmental conditions; Calculating the cement slurry density range according to the plurality of first data; Inputting the plurality of second data into a plurality of preset calculation models to obtain a plurality of first structural integrity data and a plurality of second structural integrity data; wherein the plurality of first structural integrity data are used to represent the stress distribution and crack width of the first cement sheath when subjected to an external load in an assembly system comprising a casing, the first cement sheath, and a formation; and the second structural integrity data are used to quantify the inherent anti-destruction limit of the cement material and the crack width under preset stress conditions; The mechanical value range is calculated based on the plurality of first structural integrity data and the plurality of second structural integrity data.

3. The cement slurry injection method according to claim 2, characterized in that: Calculating the cement slurry density range according to the plurality of first data includes: Calculating an upper boundary of cement slurry density and a lower boundary of cement slurry density according to the plurality of first data; The cement slurry density range is generated according to the cement slurry density upper boundary and the cement slurry density lower boundary.

4. The cement slurry injection method according to claim 2, characterized in that: The multiple calculation models include a multi-layer thick-wall cylinder model, a cement sheath body failure model, and a cement sheath micro-annulus expansion model; the multiple first structural integrity data include a first radial stress, a first tangential stress, and a first micro-annulus; the multiple second structural integrity data include a second radial stress, a second tangential stress, and a second micro-annulus; and the multiple second data are input into the preset multiple calculation models to obtain the multiple first structural integrity data and the multiple second structural integrity data, including: Inputting the plurality of second data into the multi-layer thick-walled cylinder model to obtain the first radial stress, the first tangential stress, and the first micro-annulus; wherein the multi-layer thick-walled cylinder model is used to quantify the stress state of the plastic zone of the cement sheath and the micro-annulus failure probability, the first radial stress and the first tangential stress are used to represent the radial stress and the tangential stress experienced by the first cement sheath in the assembly system, respectively, and the first micro-annulus refers to the width of a crack generated when the first cement sheath is subjected to the first radial stress and the first tangential stress in the assembly system; Inputting the plurality of second parameters into the cement sheath body failure model to obtain the second radial stress and the second tangential stress; wherein the cement sheath body failure model is used to evaluate the anti-destruction capability of the cement material, and the second radial stress and the second tangential stress are used to represent the ability of the cement material of the first cement slurry to resist radial extrusion failure and tangential extrusion failure, respectively; The multiple second parameters are input into the cement sheath micro-annulus expansion model to obtain the second micro-annulus; wherein the cement sheath micro-annulus expansion model is used to quantify the width of the micro-annulus, and the second micro-annulus refers to the width of the crack that appears in the first cement sheath under preset stress conditions.

5. The cement slurry injection method according to claim 4, characterized in that: Calculating the mechanical value range according to the plurality of first structural integrity data and the plurality of second structural integrity data includes: calculating a first difference between the first radial stress and the second radial stress, a second difference between the first tangential stress and the second tangential stress, and a third difference between the first microannulus and the second microannulus; In response to the first difference, the second difference, and the third difference being all less than a preset difference threshold, calculating a first average value of the first radial stress and the second radial stress, a second average value of the first tangential stress and the second tangential stress, and a third average value of the first microannulus and the second microannulus; The stress value range is obtained by determining a range based on the first average value, the second average value, and the third average value.

6. The cement slurry injection method according to claim 1, characterized in that: The first density is outside the cement slurry density range, or the first mechanical parameter is outside the mechanical value range, and the first density or the first mechanical parameter is adjusted to obtain a second density and a second mechanical parameter, including: The first density is outside the cement slurry density range, and the first mechanical parameter is within the mechanical value range, the first density is adjusted to obtain the second density, and the first mechanical parameter is determined as the second mechanical parameter; The first density is within the cement slurry density range, and the first mechanical parameter is outside the mechanical value range, the first mechanical parameter is adjusted to obtain the second mechanical parameter, and the first density is determined as the second density; The first density is outside the cement slurry density range, and the first mechanical parameter is outside the mechanical value range. The first density and the first mechanical parameter are adjusted to obtain the second density and the second mechanical parameter.

7. A cement slurry injection device, characterized in that: The device comprises: A first acquisition module is configured to acquire a target injection height; wherein the target injection height includes a plurality of unit heights; a first injection module, configured to inject a first cement slurry into a preset injection area; wherein the first cement slurry is a cement slurry having a density of a preset first density and mechanical parameters of preset first mechanical parameters, wherein the first mechanical parameters are used to indicate the structural integrity of a first cement annulus formed by the first cement slurry; a second injection module, configured to inject the first cement slurry into the injection area in response to the first cement slurry having been injected to a first height, the first density being within a preset cement slurry density range, and the first mechanical parameter being within a preset mechanical value range; wherein the first height is less than the target injection height, and the first height includes a plurality of unit heights; an adjustment module, configured to adjust the first density or the first mechanical parameter to obtain a second density and a second mechanical parameter in response to the first cement slurry having been injected to the first height and the first density being outside the cement slurry density range or the first mechanical parameter being outside the mechanical value range; wherein the second density is within the cement slurry density range and the second mechanical parameter is within the mechanical value range; a third injection module, configured to inject a second cement slurry into the injection area; wherein the second cement slurry is a cement slurry having a density of the second density and mechanical parameters of the second mechanical parameters; The injection stopping module is configured to stop injection in response to the second cement slurry being injected to the target injection height.

8. An electronic device, characterized in that: include: a processor, and a memory communicatively connected to the processor; The memory stores computer-executable instructions; When the processor executes the computer-executable instructions stored in the memory, it is used to implement the cement slurry injection method according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the cement slurry injection method according to any one of claims 1 to 6.

10. A computer program product, characterized in that The method comprises a computer program, which, when executed by a processor, is used to implement the cement slurry injection method according to any one of claims 1 to 6.

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