Virtual well establishing method and system for non-target complex stratum well wall stability prediction

Abstract

The invention discloses a virtual well establishing method and system for non-target complex stratum well wall stability prediction. The method comprises the steps that regional well data are determined; on the basis of the regional well data, reconstructing key missing data to obtain regional well shaft data, and assigning to obtain virtual well data; performing depth adjustment on the virtual well data; and carrying out compaction correction on the virtual well data after depth adjustment and correction to complete the establishment of the virtual well. The virtual well established by the method is complete and reliable in key data, and can provide solid data foundation guarantee for on-site actual drilling parameter optimization and adjustment research.

Description

Technical Field

[0001] The invention belongs to the technical field of oil drilling and rock mechanics, and in particular relates to a virtual well establishment method and system for predicting wellbore stability in non-target complex formations. Background Art

[0002] In deep and ultra-deep oil drilling projects, the prediction of wellbore stability in non-target complex formations that have not been drilled is one of the current technical challenges in exploratory well drilling. Accurately predicting the wellbore stability characteristics of non-target complex formations is of great significance for optimizing drilling parameters, reducing drilling complexity, improving drilling effectiveness, and ensuring the drilling of target layers. The current prediction of wellbore stability in non-target layers and the formulation of related drilling parameters are mostly based on the engineering experience of adjacent similar wells as a reference, and roughly give drilling engineering parameters such as pore pressure, collapse pressure, leakage pressure, fracture pressure, and safe mud window range of non-target complex formations. During the actual drilling process, due to the large difference between these key parameters and the actual formation parameters, it often leads to underground complexities such as leakage, collapse, and stuck drill pipe in the drilling, which inevitably increases the drilling cycle. In worse cases, it even leads to the scrapping of the wellbore, seriously affecting the progress of oil and gas exploration.

[0003] The well to be drilled is the target well that has not been drilled yet. The data of non-target complex formations of the well to be drilled is lacking, and the drilling construction parameters provided in the drilling engineering plan and drilling design before drilling are unreliable; the reference well is a well that has already encountered non-target complex formations geologically, and the data is relatively rich. However, due to different formation depths, different structures, different wellbore inclinations, and incomplete wellbore data of the reference well, the reference construction parameters cannot be directly borrowed to the well to be drilled.

[0004] The existing construction method is to construct a virtual well based on post-stack seismic data and existing logging data and geological data in the work area. It has wide applicability. The virtual well curve is used in subsequent reservoir description, high-precision seismic inversion and other links to constrain the spatial variation law. Alternatively, the natural gamma curve of the virtual well is obtained by superimposing the second natural gamma curve controlled by the astronomical cycle and the third natural gamma curve determined by the geological model information on the basis of the first natural gamma curve obtained by the wave impedance data, so as to fully consider the high continuity of seismic data in the horizontal direction, the high resolution of the actual drilling data in the vertical direction and the constraints of the geological model. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a method and system for establishing a virtual well for predicting wellbore stability in non-target complex formations in view of the deficiencies in the above-mentioned prior art, so as to solve the technical problem that there is a lack of data to be drilled and it is impossible to perform quantitative wellbore stability prediction.

[0006] The present invention adopts the following technical solutions:

[0007] The method for establishing a virtual well for predicting wellbore stability in non-target complex formations includes the following steps:

[0008] S1. Determine regional well data;

[0009] S2, based on the regional well data obtained in step S1, reconstruct the key missing data, obtain the regional wellbore data, and assign values ​​to obtain the virtual well data;

[0010] S3, performing depth calibration on the virtual well data obtained in step S2;

[0011] S4. Perform compaction correction on the virtual well data after depth adjustment in step S3 to complete the establishment of the virtual well.

[0012] Specifically, step S1 is as follows:

[0013] S101, searching and sorting out the surrounding wells of the target well that has not been drilled, and determining the wells that have encountered non-target complex formations;

[0014] S102, sorting out the wells that have encountered non-target complex formations obtained in step S101, determining the wellbore data acquisition status and key information of each well, and evaluating the quality of the acquired data;

[0015] S103. Based on the result obtained in step S102, wells with complete data and the best quality of recorded data are selected as reference wells for virtual wells.

[0016] Furthermore, in step S102, the key data include natural gamma, well diameter, drill bit vertical well, density, longitudinal wave time difference, and shear wave time difference.

[0017] Specifically, step S2 is as follows:

[0018] S201, clarifying the specific data missing from the reference well obtained in step S1;

[0019] S202: Screen the specific data obtained in step S201 based on the data reconstruction method.

[0020] Furthermore, in step S202, the wellbore data of adjacent wells are used to establish the relationship between the existing data by adopting a multivariate linear regression or neural network method to ensure that the reconstructed data is equal to the measured data.

[0021] Going further, reconstruct the key missing data as follows:

[0022] DEN(reconstruction)=0.00441*GR-0.01074*DTC+2.9508

[0023] Among them, DEN is density logging data, GR is natural gamma logging data, and DTC is compressional wave time difference logging data.

[0024] Specifically, in step S3, the wellbore data and geological stratification of the reference well obtained in step S1 are adjusted to a set depth range according to the geological stratification of the virtual well, and the corresponding geological stratification ranges of the virtual well are assigned in turn to construct the wellbore data of the virtual well.

[0025] Specifically, in step S4, the compaction correction is performed using acoustic wave time difference adjustment, specifically:

[0026] DTC (after correction) = DTC (before correction) * Cp

[0027] Wherein, Cp is the correction parameter.

[0028] Furthermore, the virtual well is established as follows:

[0029] The data of the reference well is used to assign data to the well to be drilled, and the virtual wellbore data of the well to be drilled with complete data is constructed. The wellbore stability analysis results are used as the basis for optimizing drilling parameters.

[0030] In a second aspect, an embodiment of the present invention provides a virtual well establishment system for predicting wellbore stability in non-target complex formations, comprising:

[0031] Data module, determining regional well data;

[0032] The reconstruction module reconstructs the key missing data based on the regional well data obtained by the data module, obtains the regional wellbore data, and assigns values ​​to obtain the virtual well data;

[0033] A calibration module is used to perform depth calibration on the virtual well data obtained by the reconstruction module;

[0034] The output module performs compaction correction on the virtual well data after depth adjustment by the adjustment module to complete the establishment of the virtual well.

[0035] Compared with the prior art, the present invention has at least the following beneficial effects:

[0036] A virtual well establishment method for predicting wellbore stability in non-target complex formations uses data reconstruction technology to establish wellbore data to be drilled, providing key data for the virtual well required for wellbore stability prediction; virtual well depth adjustment is used to make the wellbore data of the virtual well conform to the formation layering and reflect the formation characteristics to be drilled; compaction correction technology is used to consider the key factor of formation compaction, making the wellbore data of the virtual well more scientific and reasonable, thereby making the wellbore stability evaluation results and optimized drilling parameters more reliable. Through the optimized drilling parameters, non-target complex formations can be drilled smoothly and the drilling efficiency can be improved.

[0037] Furthermore, step S1 carries out neighboring well optimization and data quality control around the target well to be drilled, and obtains wellbore data that can represent the target well to be drilled, that is, establishes basic data of the virtual wellbore; through data comparison and optimization of multiple neighboring wells, a representative reference well is identified.

[0038] Furthermore, step S2 constructs the missing key data of the reference well through a data reconstruction method to achieve data completeness for establishing the virtual well model, and constructs a relationship between the missing data and other data through the relationship between different logging data, thereby achieving the construction of the missing data of the virtual well.

[0039] Furthermore, the missing key data of the virtual well is constructed through the data reconstruction method to achieve data completeness of the virtual well. Through the relationship between different logging data, the relationship between the missing data and other data is constructed, thereby realizing the construction of the missing data of the virtual well.

[0040] Furthermore, the acoustic time difference adjustment is used to perform compaction correction. With the help of the sensitivity of the acoustic time difference curve to the burial depth, a correction formula is established. The formula is used to process the virtual well data so that the established virtual well model can better represent the formation characteristics.

[0041] It can be understood that the beneficial effects of the second aspect mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here.

[0042] In summary, the key data of the virtual well established by the method of the present invention is complete and reliable, and provides a data basis guarantee for the optimization and adjustment of on-site actual drilling parameters.

[0043] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 is the relationship diagram between the virtual well and the reference well;

[0045] Figure 2 This is a comparison chart between the reconstructed data and the measured data;

[0046] Figure 3 Assign values ​​and adjust depth for virtual well data;

[0047] Figure 4 Compact and correct the acoustic time difference data of virtual wells;

[0048] Figure 5 Establishing a flow chart for the virtual well of the present invention;

[0049] Figure 6 Create a schematic diagram of the idea for the virtual well;

[0050] Figure 7 A schematic diagram of data integrity check for a virtual well to be drilled;

[0051] Figure 8 This is a schematic diagram of the virtual wellbore stability evaluation results and drilling parameter optimization;

[0052] Fig. 9 A schematic diagram of a computer device provided by an embodiment of the present invention;

[0053] Fig.10 The block diagram of a chip provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0054] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0055] In the description of the present invention, it should be understood that the terms “include” and “comprises” indicate the presence of described features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or collections thereof.

[0056] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0057] It should be further understood that the term "and / or" used in the present specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes these combinations. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in the present invention generally indicates that the associated objects are in an "or" relationship.

[0058] It should be understood that, although the terms first, second, third, etc. may be used to describe preset ranges, etc. in the embodiments of the present invention, these preset ranges should not be limited to these terms. These terms are only used to distinguish preset ranges from each other. For example, without departing from the scope of the embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0059] The word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to determining" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)", depending on the context.

[0060] Various structural schematic diagrams of the embodiments disclosed in the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0061] In order to better drill through non-target complex formations, reduce drilling complexity and improve drilling effectiveness during oil drilling, it is necessary to carry out targeted and detailed prediction of wellbore stability in non-target complex formations, optimize and design drilling engineering parameters according to the predicted formation parameters, and reduce the drilling complexity of complex non-target complex formations and improve drilling efficiency. In order to meet the needs of wellbore stability prediction in non-target complex formations, it is necessary to construct the wellbore data to be drilled and form a virtual well with complete formation parameters; based on this virtual well, conduct wellbore stability research in non-target complex formations, and then optimize the formulation of drilling parameters.

[0062] The present invention provides a method for establishing a virtual well for predicting wellbore stability in non-target complex formations, which combines the wellbore data of adjacent wells, reconstruction of key missing data, virtual well depth adjustment of reference wells, compaction correction and other technologies and steps to achieve the establishment of virtual wells in non-target complex formations. From the sorting of regional well data to the establishment of a virtual well for predicting wellbore stability before drilling in non-target complex formations, the whole process is logically rigorous and comprehensive. The key data of the virtual well established by this method is complete and reliable, which can provide a solid data foundation for the optimization and adjustment research of on-site actual drilling parameters.

[0063] See also Figure 5 The present invention provides a virtual well establishment method for predicting wellbore stability in non-target complex formations, comprising the following steps:

[0064] S1. Regional well data sorting and optimization;

[0065] Data optimization is a preparatory work for technical methods.

[0066] See also Figure 1, explaining the relationship between the reference well and the well to be drilled. Through the optimization of neighboring wells, the well with the most complete data is selected. The data of the reference well is supplemented with missing data through data construction, and the construction of virtual well data is realized through compaction correction and other processing.

[0067] S101. Search and sort out the surrounding wells of the target well that has not been drilled, and further clarify which wells have encountered non-target complex formations;

[0068] For example, including Well A1, Well A2, etc.

[0069] S102. Sort out the wells that have encountered non-target complex formations, further clarify the wellbore data acquisition status of each well, confirm whether the key information such as natural gamma, well diameter, drill bit vertical well, density, longitudinal wave time difference, shear wave time difference, etc. are complete, and evaluate the quality of the acquired data;

[0070] For example, the adjacent well information and data quality are as follows:

[0071] The data collected from Well A1 include natural gamma (GR), well diameter (CAL), bit vertical well (BIT), density (DEN), and longitudinal wave time difference (DT); the data quality is good;

[0072] The data collected from Well A2 include natural gamma, well diameter, drill bit vertical well, and P-wave time difference; the data quality is poor;

[0073] The data collected from Well A3 include natural gamma, well diameter, drill bit vertical well, density, and longitudinal wave time difference; the data quality is average.

[0074] S103. Compare the data of the above-mentioned neighboring wells, and select a well with relatively complete data and better recorded data quality as a reference well for the virtual well.

[0075] For example, through comparative analysis of the completeness and data quality of adjacent well data, it is believed that Well A1 is suitable as a reference well for the target well.

[0076] S2, reconstruction of key missing data;

[0077] Data reconstruction can supplement and establish reliable basic wellbore data.

[0078] S201. Clarify the specific data missing from the reference wells;

[0079] For example, Well A1 lacks the key data of shear wave time difference; Well A2 (if used as a reference well) lacks density and shear wave time difference.

[0080] S202. Data reconstruction method and optimization.

[0081] By using the borehole data of adjacent wells and adopting technical methods such as multivariate linear regression and neural network, the relationship between the existing data is established and it is ensured that the reconstructed data is basically equal to the measured data.

[0082] For example, Well A2 measured natural gamma and P-wave time difference, but lacked density curve; Well A3 measured natural gamma, P-wave time difference, and density. Well A3 can be used to build a model, and the established formula is as follows:

[0083] DEN(reconstruction)=0.00441*GR-0.01074*DTC+2.9508

[0084] The reconstructed density data is compared with the measured data. Figure 2 The figure shows the curve reconstruction verification results. The model is established by using wells with complete data. In the figure, the relationship f(DEN) = a*GR + b*DT + c is established by using well A. The relationship is applied to well B, and the calculated DEN data is compared with the DEN data actually measured in well B. The comparison shows that the calculated curve is basically the same as the measured curve, with a small error, and the reconstructed model is reliable.

[0085] The above multivariate regression formula was used to reconstruct the density curve of Well A2 and supplement the missing data.

[0086] S3. Reference well and virtual well depth calibration

[0087] Depth calibration can obtain wellbore data of virtual well depth.

[0088] The wellbore data and geological stratification of the reference well are adjusted to a reasonable depth range according to the geological stratification of the virtual well, and the wellbore data of the virtual well are preliminarily constructed.

[0089] See also Figure 3 The reference well is a well that has been drilled, with complete geological stratification and wellbore data; the virtual well is a well to be drilled, with no wellbore data. This part of the work is to assign the data of the reference well to the corresponding geological stratification range of the virtual well in turn according to the geological stratification depth range, so as to achieve complete virtual well data.

[0090] S4: Compact and calibrate to complete the establishment of the virtual well.

[0091] S401. Compaction correction can obtain reasonable virtual well data.

[0092] The wellbore data and geological layer depth of the reference well are relatively shallow, while the actual well to be drilled is buried deep. It is unreasonable to directly assign the reference well data to the virtual well to be drilled according to the formation. This mainly refers to the longitudinal wave time difference data affected by the formation depth.

[0093] The depth adjustment of acoustic time difference varies depending on the block and geological depth. The more practical acoustic time difference adjustment formula is:

[0094] DTC (after correction) = DTC (before correction) * Cp

[0095] Cp=a*(1.68-0.0002*Depth)

[0096] Among them, Cp is the correction parameter, and parameter a is a fixed parameter related to the region.

[0097] See also Figure 4 , Comparison of longitudinal wave time difference before and after adjustment of a well: the pink reconstructed acoustic wave time difference (after correction) is the curve after depth adjustment according to the above formula, which can better reflect the acoustic wave time difference properties of the formation at a deeper burial depth than the blue reconstructed acoustic wave curve (before correction).

[0098] S402: Establish a virtual well.

[0099] This well is an oil and gas well waiting to be drilled. There is no wellbore data, so it is impossible to conduct a wellbore stability evaluation to optimize the drilling construction parameters.

[0100] In order to optimize drilling parameters, complete reference well data is used to assign the well to be drilled, and complete virtual wellbore data of the well to be drilled is constructed to carry out subsequent wellbore stability analysis. The wellbore stability analysis results serve as the basis for drilling parameter optimization.

[0101] In another embodiment of the present invention, a virtual well establishment system for predicting wellbore stability in non-purpose complex formations is provided. The system can be used to implement the above-mentioned virtual well establishment method for predicting wellbore stability in non-purpose complex formations. Specifically, the virtual well establishment system for predicting wellbore stability in non-purpose complex formations includes a data module, a reconstruction module, a calibration module and an output module.

[0102] Among them, the data module determines the regional well data;

[0103] The reconstruction module reconstructs the key missing data based on the regional well data obtained by the data module, obtains the regional wellbore data, and assigns values ​​to obtain the virtual well data;

[0104] A calibration module is used to perform depth calibration on the virtual well data obtained by the reconstruction module;

[0105] The output module performs compaction correction on the virtual well data after depth adjustment by the adjustment module to complete the establishment of the virtual well.

[0106] In another embodiment of the present invention, a terminal device is provided, which includes a processor and a memory, wherein the memory is used to store a computer program, the computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, which is suitable for implementing one or more instructions, and is specifically suitable for loading and executing one or more instructions to implement the corresponding method flow or corresponding function; the processor described in the embodiment of the present invention can be used for the operation of the virtual well establishment method for non-purpose complex formation well wall stability prediction, including:

[0107] Determine regional well data; based on the regional well data, reconstruct key missing data, obtain regional wellbore data, and assign values ​​to obtain virtual well data; perform depth adjustment on the virtual well data; perform compaction correction on the depth-adjusted virtual well data to complete the establishment of the virtual well.

[0108] See also Fig. 9 , the terminal device is a computer device. The computer device 60 of this embodiment includes: a processor 61, a memory 62, and a computer program 63 stored in the memory 62 and executable on the processor 61. When the computer program 63 is executed by the processor 61, the method for calculating the fluid composition in the reservoir transformation wellbore in the embodiment is realized. To avoid repetition, it is not described one by one here. Alternatively, when the computer program 63 is executed by the processor 61, the functions of each model / unit in the virtual well establishment system for predicting the wellbore stability of non-purpose complex formations in the embodiment are realized. To avoid repetition, it is not described one by one here.

[0109] The computer device 60 may be a computing device such as a desktop computer, a notebook, a PDA, or a cloud server. The computer device 60 may include, but is not limited to, a processor 61 and a memory 62. Those skilled in the art will appreciate that Fig. 9 This is only an example of the computer device 60 and does not constitute a limitation of the computer device 60. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the computer device may also include input and output devices, network access devices, buses, etc.

[0110] The processor 61 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0111] The memory 62 may be an internal storage unit of the computer device 60, such as a hard disk or memory of the computer device 60. The memory 62 may also be an external storage device of the computer device 60, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc., equipped on the computer device 60.

[0112] Furthermore, the memory 62 may include both an internal storage unit of the computer device 60 and an external storage device. The memory 62 is used to store computer programs and other programs and data required by the computer device. The memory 62 may also be used to temporarily store data that has been output or is to be output.

[0113] See also Fig.10 , the terminal device is a chip, and the chip 600 of this embodiment includes a processor 622, which may be one or more, and a memory 632 for storing a computer program executable by the processor 622. The computer program stored in the memory 632 may include one or more modules, each corresponding to a set of instructions. In addition, the processor 622 may be configured to execute the computer program to execute the above-mentioned virtual well establishment method for predicting wellbore stability in non-target complex formations.

[0114] In addition, the chip 600 may further include a power supply component 626 and a communication component 650, wherein the power supply component 626 may be configured to perform power management of the chip 600, and the communication component 650 may be configured to implement communication, for example, wired or wireless communication, of the chip 600. In addition, the chip 600 may further include an input / output (I / O) interface 658. The chip 600 may operate based on an operating system stored in the memory 632.

[0115] In another embodiment of the present invention, the present invention further provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a terminal device for storing programs and data. It can be understood that the computer-readable storage medium here can include both the built-in storage medium in the terminal device and the extended storage medium supported by the terminal device. The computer-readable storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by the processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory, or a non-volatile memory (Non-Volatile Memory), such as at least one disk memory.

[0116] The processor may load and execute one or more instructions stored in a computer-readable storage medium to implement the corresponding steps of the method for establishing a virtual well for predicting wellbore stability in a non-target complex formation in the above embodiment; the processor may load and execute the following steps of one or more instructions in the computer-readable storage medium:

[0117] Determine regional well data; based on the regional well data, reconstruct key missing data, obtain regional wellbore data, and assign values ​​to obtain virtual well data; perform depth adjustment on the virtual well data; perform compaction correction on the depth-adjusted virtual well data to complete the establishment of the virtual well.

[0118] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention described and shown in the drawings here can usually be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0119] Example

[0120] See also Figure 6 Well A to be drilled is a target well that has not been drilled yet. The drilling engineering parameters for non-target complex formations provided by the drilling design of this well have poor reliability, and the possibility of drilling complications occurring during actual drilling is high.

[0121] Reference well B is a well that has encountered non-target complex strata geologically and has relatively rich data.

[0122] The reference well measured wellbore data such as natural gamma (GR), wellbore diameter (CAL), bit verticality (BIT), density (DEN), and compressional time difference (DT), and the data quality was good.

[0123] First, we sorted out the reference well B which had relatively complete data and had drilled through non-target complex formations.

[0124] Second, compare the stratigraphic sequence of the reference well and the stratigraphic sequence of the well to be drilled, borrow the reference well data from the well to be drilled, and perform depth adjustment, that is, resample the data of each stratigraphic layer of the reference well by stretching, compressing, etc. in proportion, so that the wellbore data of the well to be drilled can scientifically and reasonably reflect the stratigraphic conditions.

[0125] Third, the data reconstruction method is used to construct the shear time difference (DTS) required for wellbore stability prediction.

[0126] Fourth, considering that the reference well is shallowly buried and the well to be drilled is deeply buried, the borrowed P-wave time difference needs to be compacted and corrected to obtain the corrected P-wave time difference.

[0127] Fifth, sort out the wellbore data integrity of the virtual well to be drilled, ensure that the key data natural gamma (GR), wellbore diameter (CAL), bit vertical well (BIT), density (DEN), longitudinal wave time difference (DTC), and shear wave time difference (DTS) are complete, and meet the conditions for wellbore stability evaluation, such as Figure 2 shown.

[0128] Sixth, use virtual well data to conduct wellbore stability analysis in non-target complex formations and obtain key drilling parameters.

[0129] See also Figure 7 , demonstrating the data integrity of the virtual well. The method of the present invention realizes the processing of borrowing data from reference wells, reconstructing key data, and correcting data, and realizes the construction of virtual well data to be drilled. The advantages and benefits of the present invention are that a virtual wellbore model to be drilled is constructed, which provides a basis for subsequent prediction of wellbore stability.

[0130] See also Figure 8 , showing the stability characteristics of the wellbore of the well to be drilled; the wellbore stability prediction result is calculated by the virtual well model constructed by the method of the present invention, and a "virtual wellbore model" of the well that has not yet been drilled is obtained through a scientific and reasonable data processing method, and the wellbore stability prediction of the well to be drilled is realized by using this model.

[0131] In summary, the present invention provides a method and system for establishing a virtual well for predicting wellbore stability in non-target complex formations. This method makes full use of the wellbore data of the reference well and adopts technologies and steps such as key missing data reconstruction, depth adjustment, and compaction correction to achieve the establishment of a virtual well in the non-target complex formation to be drilled, thereby ensuring that the subsequent drilling parameter optimization work can be carried out smoothly.

[0132] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0133] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0134] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed in the present invention can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0135] In the embodiments provided by the present invention, it should be understood that the disclosed devices / terminals and methods can be implemented in other ways. For example, the device / terminal embodiments described above are only schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0136] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0137] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0138] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium, etc. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0139] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1A device that provides the functions specified in a block or multiple blocks.

[0140] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0141] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0142] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A virtual well establishment method for predicting wellbore stability in non-target complex formations, characterized in that: The following steps are involved: S1. Determine regional well data; S2, based on the regional well data obtained in step S1, reconstruct the key missing data, obtain the regional wellbore data, and assign values ​​to obtain the virtual well data; S3, performing depth calibration on the virtual well data obtained in step S2; S4. Perform compaction correction on the virtual well data after depth adjustment in step S3 to complete the establishment of the virtual well.

2. The method for establishing a virtual well for predicting wellbore stability in non-target complex formations according to claim 1, characterized in that: Step S1 is specifically as follows: S101, searching and sorting out the surrounding wells of the target well that has not been drilled, and determining the wells that have encountered non-target complex formations; S102, sorting out the wells that have encountered non-target complex formations obtained in step S101, determining the wellbore data acquisition status and key information of each well, and evaluating the quality of the acquired data; S103. Based on the result obtained in step S102, wells with complete data and the best quality of recorded data are selected as reference wells for virtual wells.

3. The method for establishing a virtual well for predicting wellbore stability in non-target complex formations according to claim 2, characterized in that: In step S102, key data include natural gamma, well diameter, drill bit vertical well, density, longitudinal wave time difference, and shear wave time difference.

4. The method for establishing a virtual well for predicting wellbore stability in non-target complex formations according to claim 1, characterized in that: Step S2 is specifically as follows: S201, clarifying the specific data missing from the reference well obtained in step S1; S202: Screen the specific data obtained in step S201 based on the data reconstruction method.

5. The method for establishing a virtual well for predicting wellbore stability in non-target complex formations according to claim 4, characterized in that: In step S202, the wellbore data of adjacent wells are used to establish the relationship between the existing data by adopting multivariate linear regression or neural network method to ensure that the reconstructed data is equal to the measured data.

6. The method for establishing a virtual well for predicting wellbore stability in non-target complex formations according to claim 5, characterized in that: Reconstruct the key missing data as follows: DEN(reconstruction)=0.00441*GR-0.01074*DTC+2.9508 Among them, DEN is density logging data, GR is natural gamma logging data, and DTC is compressional wave time difference logging data.

7. The method for establishing a virtual well for predicting wellbore stability in non-target complex formations according to claim 1, characterized in that: In step S3, the wellbore data and geological stratification of the reference well obtained in step S1 are adjusted to a set depth range according to the geological stratification of the virtual well, and the corresponding geological stratification ranges of the virtual well are assigned in turn to construct the wellbore data of the virtual well.

8. The method for establishing a virtual well for predicting wellbore stability in non-target complex formations according to claim 1, characterized in that: In step S4, the compaction correction is performed using acoustic wave time difference adjustment, specifically: DTC (after correction) = DTC (before correction) * Cp Wherein, Cp is the correction parameter.

9. The method for establishing a virtual well for predicting wellbore stability in non-target complex formations according to claim 8, characterized in that: The specific steps of establishing a virtual well are as follows: The data of the reference well is used to assign data to the well to be drilled, and the virtual wellbore data of the well to be drilled with complete data is constructed. The wellbore stability analysis results are used as the basis for optimizing drilling parameters.

10. A virtual well establishment system for predicting wellbore stability in non-target complex formations, characterized in that: include: Data module, determining regional well data; The reconstruction module reconstructs the key missing data based on the regional well data obtained by the data module, obtains the regional wellbore data, and assigns values ​​to obtain the virtual well data; A calibration module is used to perform depth calibration on the virtual well data obtained by the reconstruction module; The output module performs compaction correction on the virtual well data after depth adjustment by the adjustment module to complete the establishment of the virtual well.

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