A method, device and medium for predicting wellbore stability before drilling

Abstract

The application provides a wellbore stability prediction method, device and medium before drilling, and relates to the technical field of petroleum engineering, and comprises the following steps: obtaining a three-dimensional seismic data body and a seismic interval velocity of a to-be-drilled well area, well logging interpretation data of an adjacent well, and determining simulated well logging data of the to-be-drilled well; the adjacent well is a well adjacent to the to-be-drilled well; a fracture structure model of the to-be-drilled well area is established according to the simulated well logging data and the three-dimensional seismic data body; a formation pressure model, a rock mechanics attribute model and a ground stress model of the to-be-drilled well area are established based on the fracture structure model, the well logging interpretation data and the seismic interval velocity; a finite element model of the to-be-drilled well area is established according to the fracture structure model, the formation pressure model, the rock mechanics attribute model and the ground stress model; finite element forward modeling is carried out based on the finite element model to obtain a collapse pressure, so as to predict the wellbore stability of the to-be-drilled well. In this way, the influences of faults and fractures, ground stress and formation pressure on the wellbore stability are fully considered.

Description

Technical Field

[0001] This invention relates to the field of petroleum engineering technology, and more specifically, to a method, apparatus, and medium for predicting wellbore stability before drilling. Background Technology

[0002] As drilling depths increase, downhole leakage accidents become more frequent, causing wellbore instability and severely hindering the efficient development of oil and gas resources, significantly impacting both economic and time costs. Therefore, predicting wellbore stability before drilling is crucial.

[0003] Currently, numerical simulation methods are commonly used to predict wellbore stability. However, existing technologies do not consider the effects of fault fractures, in-situ stress, and formation pressure on wellbore stability, leading to inaccurate predictions. Furthermore, current technologies predict wellbore stability during the drilling process, increasing the workload.

[0004] To address the problems of existing technologies, this invention provides a method, device, and medium for predicting wellbore stability before drilling. Summary of the Invention

[0005] To address the problems of existing technologies, this invention provides a method, apparatus, and medium for predicting wellbore stability before drilling. The method includes:

[0006] Acquire the 3D seismic data volume and seismic layer velocity of the area to be drilled, well logging interpretation data of adjacent wells, and determine the simulated well logging data of the well to be drilled; the adjacent wells are those adjacent to the well to be drilled.

[0007] Based on the simulated logging data and the three-dimensional seismic data volume, a fracture structure model of the area to be drilled is established.

[0008] Based on the fracture structure model, the well logging interpretation data, and the seismic layer velocity, a formation pressure model, a rock mechanical property model, and a geostress model are established for the area to be drilled.

[0009] Based on the fracture structure model, the formation pressure model, the rock mechanical property model, and the geostress model, a finite element model of the area to be drilled is established.

[0010] Finite element forward modeling is performed based on the finite element model to obtain the collapse pressure, thereby predicting the wellbore stability of the well to be drilled.

[0011] According to an embodiment of the present invention, the crack structure model is constructed through the following steps:

[0012] Based on the simulated logging data, a three-dimensional geological structure model of the area to be drilled is constructed.

[0013] Based on the three-dimensional seismic data volume, a fracture distribution model of the area to be drilled is constructed;

[0014] The fracture structure model is obtained by integrating the three-dimensional geological structure model and the fracture distribution model.

[0015] The simulated well logging data includes geological structural data and seismic interpretation stratigraphic data.

[0016] According to an embodiment of the present invention, the three-dimensional geological structure model is constructed through the following steps:

[0017] Based on the simulated logging data, the formation data of the area to be drilled are determined;

[0018] Interpolate the stratigraphic data to generate a stratigraphic plane;

[0019] Based on the data from the adjacent wells, the strata are corrected, and the strata are divided into vertical and horizontal grids to construct the three-dimensional geological structure model.

[0020] According to an embodiment of the present invention, the crack propagation model is constructed through the following steps:

[0021] Ant tracking technology is used to identify faults and fractures in the three-dimensional seismic data volume in order to construct a fracture distribution model.

[0022] According to one embodiment of the present invention, the well logging interpretation data includes: formation pressure, geostress, and rock mechanical parameter data;

[0023] The formation pressure model, the geostress model, and the rock mechanical property model are established through the following steps:

[0024] The well logging interpretation data are coarsened to the fracture structure model respectively;

[0025] In the fracture structure model, well logging interpretation data and seismic layer velocity are used as constraints to perform inter-well interpolation to establish the formation pressure model, the geostress model, and the rock mechanical property model accordingly.

[0026] The rock mechanical property model includes: an elastic modulus property model, a Poisson's ratio property model, and a pore pressure property model.

[0027] According to an embodiment of the present invention, the finite element model is established through the following steps:

[0028] Based on the seismic interpretation stratigraphic data and the fault and fracture data in the fracture structure model, the geological geometric model of the area to be drilled is reconstructed.

[0029] The fault planes and bedding planes of the geological geometric model are meshed, the maximum value and direction of the geostress in the formation pressure model are used as boundary conditions, and material properties are assigned based on the formation pressure model and the rock mechanical property model to establish the finite element model.

[0030] According to an embodiment of the present invention, material properties are assigned through the following steps:

[0031] Data from the rock mechanics property model and the formation pressure model are extracted, and a three-dimensional interpolation function for the well perimeter region is constructed to assign material property values ​​to the finite element model.

[0032] According to one embodiment of the present invention, the drilling area includes one of the following: shale formation, carbonate formation, and sandstone formation.

[0033] According to another aspect of the invention, a storage medium is also provided, comprising a series of instructions for performing the steps of the method as described in any of the preceding claims.

[0034] According to another aspect of the invention, a pre-drilling wellbore stability prediction device is also provided, which performs the method as described in any of the preceding claims, the device comprising:

[0035] The acquisition module is used to acquire the three-dimensional seismic data volume and seismic layer velocity of the area to be drilled, the logging interpretation data of adjacent wells, and to determine the simulated logging data of the well to be drilled; the adjacent wells are those adjacent to the well to be drilled.

[0036] The first module is used to establish a fracture structure model of the area to be drilled based on the simulated logging data and the three-dimensional seismic data volume.

[0037] The second module is used to establish a formation pressure model, a rock mechanical property model, and a geostress model for the area to be drilled, based on the fracture structure model, the well logging interpretation data, and the seismic layer velocity.

[0038] The third module is used to establish a finite element model of the area to be drilled based on the fracture structure model, the formation pressure model, the rock mechanical property model, and the geostress model.

[0039] The prediction module is used to perform finite element forward modeling based on the finite element model to obtain the collapse pressure, so as to predict the wellbore stability of the well to be drilled.

[0040] This invention provides a method, apparatus, and medium for predicting wellbore stability before drilling, which has the following advantages compared with the prior art:

[0041] This invention first acquires the 3D seismic data volume and seismic layer velocity of the area to be drilled, as well as the well logging interpretation data of adjacent wells, and determines the simulated well logging data of the well to be drilled. Based on the simulated well logging data and the 3D seismic data volume, a fracture structure model of the area to be drilled is established to consider the impact of fracture development on wellbore stability. Next, based on the fracture structure model, well logging interpretation data, and seismic layer velocity, a formation pressure model, a rock mechanical property model, and a geostress model of the area to be drilled are established to consider the impact of geostress and formation pressure on wellbore stability. Subsequently, based on the fracture structure model, formation pressure model, rock mechanical property model, and geostress model, a finite element model of the area to be drilled is established for finite element forward modeling to obtain the collapse pressure and predict the wellbore stability. In this way, on the one hand, the influence of fault fractures, geostress, and formation pressure on wellbore stability is fully considered, and the relationship between collapse pressure and fault fractures, geostress, and formation pressure is established, improving the accuracy and reliability of wellbore stability. On the other hand, wellbore stability can be predicted without drilling, reducing the workload of drilling.

[0042] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the description, claims, and drawings. Attached Figure Description

[0043] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with the embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0044] Figure 1 A flowchart of a pre-drilling wellbore stability prediction method according to an embodiment of the present invention is shown;

[0045] Figure 2 A schematic diagram of the collapse pressure according to an embodiment of the present invention is shown;

[0046] Figure 3 A schematic diagram of a three-dimensional geological structure model according to an embodiment of the present invention is shown;

[0047] Figure 4 A schematic diagram of a crack propagation model according to an embodiment of the present invention is shown;

[0048] Figure 5 A schematic diagram of an elastic model property model according to an embodiment of the present invention is shown;

[0049] Figure 6 A schematic diagram of a Poisson's ratio property model according to an embodiment of the present invention is shown;

[0050] Figure 7 A schematic diagram of a pore pressure property model according to an embodiment of the present invention is shown;

[0051] Figure 8 A schematic diagram of a mesh file according to an embodiment of the present invention is shown;

[0052] Figure 9 A schematic diagram showing the magnitude of the ground stress according to an embodiment of the present invention is provided;

[0053] Figure 10 A schematic diagram showing the direction of geostress according to an embodiment of the present invention is provided;

[0054] Figure 11 A block diagram of a pre-drilling wellbore stability prediction device according to an embodiment of the present invention is shown.

[0055] In the accompanying drawings, the same parts use the same reference numerals. Also, the drawings are not drawn to scale. Detailed Implementation

[0056] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0057] To address the aforementioned shortcomings of existing technologies, this invention provides a method, apparatus, and medium for predicting wellbore stability before drilling. Figure 1 A flowchart of a pre-drilling wellbore stability prediction method according to an embodiment of the present invention is shown, the method comprising:

[0058] S101: Acquire the 3D seismic data volume and seismic layer velocity of the area to be drilled, the well logging interpretation data of adjacent wells, and determine the simulated well logging data of the well to be drilled; adjacent wells are those adjacent to the well to be drilled.

[0059] S102, Based on simulated well logging data and three-dimensional seismic data, establish a fracture structure model of the area to be drilled;

[0060] S103, based on fracture structure model, well logging interpretation data and seismic layer velocity, establish formation pressure model, rock mechanical property model and geostress model of the area to be drilled;

[0061] S104. Based on the fracture structure model, formation pressure model, rock mechanical property model and geostress model, a finite element model of the area to be drilled is established.

[0062] S105, based on the finite element model, finite element forward modeling is performed to obtain the collapse pressure in order to predict the wellbore stability of the well to be drilled.

[0063] For example, the seismic layer velocity can be a three-dimensional seismic layer velocity. This can be achieved by first acquiring measured logging data and measured seismic information from adjacent wells, then fitting the measured logging data and measured seismic information to obtain the relationship between them, and finally modeling based on the seismic information of the well to be drilled and the relationship between the measured logging data and measured seismic information to obtain simulated logging data for the well to be drilled.

[0064] This can be achieved through finite element forward modeling to form an initial three-dimensional geostress field, followed by reaching initial geostress equilibrium and solving for the geostress. Then, based on the geostress, pore pressure in the rock mechanics property model, and existing formulas, the collapse pressure can be calculated, such as... Figure 2 The diagram shown illustrates the collapse pressure to predict wellbore stability.

[0065] This invention first acquires the 3D seismic data volume and seismic layer velocity of the area to be drilled, as well as the well logging interpretation data of adjacent wells, and determines the simulated well logging data of the well to be drilled. Based on the simulated well logging data and the 3D seismic data volume, a fracture structure model of the area to be drilled is established to consider the impact of fracture development on wellbore stability. Next, based on the fracture structure model, well logging interpretation data, and seismic layer velocity, a formation pressure model, a rock mechanical property model, and a geostress model of the area to be drilled are established to consider the impact of geostress and formation pressure on wellbore stability. Subsequently, based on the fracture structure model, formation pressure model, rock mechanical property model, and geostress model, a finite element model of the area to be drilled is established for finite element forward modeling to obtain the collapse pressure and predict the wellbore stability. In this way, on the one hand, the influence of fault fractures, geostress, and formation pressure on wellbore stability is fully considered, and the relationship between collapse pressure and fault fractures, geostress, and formation pressure is established, improving the accuracy and reliability of wellbore stability. On the other hand, wellbore stability can be predicted without drilling, reducing the workload of drilling.

[0066] In one possible embodiment, the crack construction model is constructed through the following steps:

[0067] Based on simulated logging data, a three-dimensional geological structure model of the area to be drilled is constructed.

[0068] Based on the 3D seismic data volume, construct a fracture distribution model of the area to be drilled;

[0069] By integrating the three-dimensional geological structure model and the fracture distribution model, a fracture structure model is obtained;

[0070] The simulated well logging data includes geological structural data and seismic interpretation stratigraphic data.

[0071] After obtaining the fracture distribution model, information about fault fractures in the fracture distribution model can be extracted and integrated into the three-dimensional geological structure model to obtain the fracture structure model.

[0072] Thus, based on the three-dimensional geological structure model and the fracture distribution model, a fracture structure model was constructed, providing a basis for the establishment of the finite element model. At the same time, the fracture structure model includes information on fault fractures, fully considering the impact of fault fractures on wellbore stability, and can obtain the relationship between fracture development and collapse pressure, thereby improving the accuracy of wellbore stability prediction.

[0073] In one possible embodiment, a three-dimensional geological structure model is constructed through the following steps:

[0074] Based on simulated logging data, determine the formation data of the area to be drilled;

[0075] Interpolate the stratigraphic data to generate the stratigraphic plane;

[0076] By combining data from adjacent wells, the strata were corrected, and the strata were divided into vertical and horizontal grids to construct a three-dimensional geological structure model.

[0077] For example, software such as Matlab can be used to interpolate the stratigraphic data to generate stratigraphic planes; then, by combining data from adjacent wells, the stratigraphic planes are corrected, and vertical and horizontal grids are divided into the stratigraphic planes to construct a three-dimensional geological structure model. Figure 3 As shown.

[0078] In this way, a three-dimensional geological structure model was constructed based on the simulated well logging data, which improved the accuracy of the three-dimensional geological structure model and provided a basis for the establishment of fracture structure model.

[0079] In one possible embodiment, a crack propagation model is constructed through the following steps:

[0080] Ant tracking technology is used to identify faults and fractures in 3D seismic data volumes in order to construct a fracture distribution model.

[0081] For example, either active ants or passive ants can be used to identify faults and fractures in a 3D seismic data volume. Then, a fracture propagation model can be constructed, such as... Figure 4 As shown, the three-dimensional distribution pattern of fault fracture development is tracked and predicted.

[0082] In this way, a fracture distribution model can be constructed based on the three-dimensional seismic data volume, which improves the accuracy of the fracture distribution model and provides a basis for the establishment of fracture structure models.

[0083] In one possible embodiment, well logging interpretation data includes: formation pressure, geostress, and rock mechanics parameter data;

[0084] The formation pressure model, geostress model, and rock mechanical property model are established through the following steps:

[0085] The well logging interpretation data were coarsened to fracture structure models;

[0086] In the fracture structure model, well logging interpretation data and seismic layer velocity are used as constraints to perform inter-well interpolation in order to establish formation pressure model, geostress model and rock mechanical property model accordingly;

[0087] The rock mechanics property model can include: an elastic modulus property model, a Poisson's ratio property model, and a pore pressure property model. Rock mechanics parameter data can include: elastic modulus, Poisson's ratio, and pore pressure.

[0088] For example, the specific steps of coarsening are as follows: the average value of the logging interpretation data of a single well is assigned to each fracture structure model through which the well trajectory passes.

[0089] In this approach, after assigning the average formation pressure value to the fracture structure model, formation pressure can be used as a constraint, and seismic velocity as a constraint for inter-well data variation. Geostatistical principles can then be used to perform inter-well interpolation to establish a corresponding formation pressure model. Alternatively, the average in-situ stress value can be assigned to the fracture structure model, and then in this model, in-situ stress can be used as a constraint, and seismic velocity as a constraint for inter-well data variation. Geostatistical principles can then be used to perform inter-well interpolation to establish a corresponding in-situ stress model. Furthermore, the average value of rock mechanics parameters can be assigned to the fracture structure model, and then in this model, rock mechanics parameters can be used as a constraint, and seismic velocity as a constraint for inter-well data variation. Geostatistical principles can then be used to perform inter-well interpolation to establish a corresponding rock mechanics property model. Figure 5 The image shows the elastic modulus property model, such as... Figure 6 The image shows a Poisson's ratio attribute model, such as... Figure 7 The figure shows the pore pressure property model.

[0090] In this way, based on the fracture structure model, well logging interpretation data, and seismic layer velocity, a formation pressure model, a rock mechanical property model, and a geostress model are established, providing a basis for the establishment of the finite element model. At the same time, it is possible to obtain the geostress distribution, formation pressure, rock mechanical parameter data, wellbore instability distribution law, and the relationship between geostress, formation pressure, rock mechanical parameter data and collapse pressure in the drilling area.

[0091] In one possible embodiment, a finite element model is established through the following steps:

[0092] Based on seismic interpretation stratigraphic data and fault fracture data in fracture tectonic models, the geological geometric model of the area to be drilled is reconstructed.

[0093] The fault planes and bedding planes of the geological geometric model are meshed, the maximum value and direction of the geostress in the formation pressure model are used as boundary conditions, and material properties are assigned based on the formation pressure model and the rock mechanics property model to establish a finite element model.

[0094] This involves using seismic interpretation horizon data and fault fracture data from fracture structure models to execute a program that reconstructs a geological geometric model. Then, triangular meshing is performed on the fault planes and horizon planes of the geological geometric model to obtain a mesh file, such as... Figure 8 As shown, material properties are then assigned values, as follows: Figure 9 and Figure 10 The maximum value and direction of the stress in the middle of the ground are used as boundary conditions to establish the finite element model.

[0095] In this way, a finite element model is established based on the fracture structure model, formation pressure model, rock mechanical property model, and geostress model to obtain the relationship between fault fractures, formation pressure, geostress, rock mechanical parameters, and collapse pressure, thereby improving the accuracy and reliability of wellbore stability prediction.

[0096] In one possible embodiment, material properties are assigned values ​​through the following steps:

[0097] Data from the rock mechanics property model and formation pressure model were extracted, and a three-dimensional interpolation function for the well perimeter region was constructed to assign material property values ​​to the finite element model.

[0098] This allows us to obtain the relationship between wellbore stability and rock mechanical properties and formation pressure, thereby improving the accuracy of wellbore stability data.

[0099] In one possible embodiment, the drilling area may include one of the following: shale formations, carbonate formations, and sandstone formations.

[0100] This increases the applicability and expands the application areas of the method.

[0101] The pre-drilling wellbore stability prediction method provided by this invention can also be used in conjunction with a computer-readable storage medium. The storage medium stores a computer program, which is executed to run the pre-drilling wellbore stability prediction method. The computer program can execute computer instructions, which include computer program code. The computer program code can be in the form of source code, object code, executable file, or some intermediate form.

[0102] Computer-readable storage media can include: any entity or device capable of carrying computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc.

[0103] It should be noted that the contents of computer-readable storage media may be appropriately added to or subtracted from the contents according to the requirements of legislation and patent practice in a jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable storage media may not include electrical carrier signals and telecommunication signals.

[0104] According to another aspect of the present invention, a pre-drilling wellbore stability prediction device is also provided, which performs a pre-drilling wellbore stability prediction method. Figure 11 A block diagram of a pre-drilling wellbore stability prediction device according to an embodiment of the present invention is shown. The device includes:

[0105] The acquisition module 510 is used to acquire the three-dimensional seismic data volume and seismic layer velocity of the area to be drilled, the logging interpretation data of adjacent wells, and to determine the simulated logging data of the well to be drilled; adjacent wells are wells adjacent to the well to be drilled;

[0106] The first module 520 is used to establish a fracture structure model of the area to be drilled based on simulated logging data and three-dimensional seismic data.

[0107] The second module 530 is used to establish a formation pressure model, a rock mechanical property model, and a geostress model for the area to be drilled, based on the fracture structure model, well logging interpretation data, and seismic layer velocity.

[0108] The third module 540 is used to establish a finite element model of the area to be drilled based on the fracture structure model, formation pressure model, rock mechanical property model and geostress model.

[0109] The prediction module 550 is used to perform finite element forward modeling based on the finite element model to obtain the collapse pressure in order to predict the wellbore stability of the well to be drilled.

[0110] In summary, this invention provides a method, apparatus, and medium for predicting wellbore stability before drilling, which has the following advantages compared with the prior art:

[0111] This invention first acquires the 3D seismic data volume and seismic layer velocity of the area to be drilled, as well as the well logging interpretation data of adjacent wells, and determines the simulated well logging data of the well to be drilled. Based on the simulated well logging data and the 3D seismic data volume, a fracture structure model of the area to be drilled is established to consider the impact of fracture development on wellbore stability. Next, based on the fracture structure model, well logging interpretation data, and seismic layer velocity, a formation pressure model, a rock mechanical property model, and a geostress model of the area to be drilled are established to consider the impact of geostress and formation pressure on wellbore stability. Subsequently, based on the fracture structure model, formation pressure model, rock mechanical property model, and geostress model, a finite element model of the area to be drilled is established for finite element forward modeling to obtain the collapse pressure and predict the wellbore stability. In this way, on the one hand, the influence of fault fractures, geostress, and formation pressure on wellbore stability is fully considered, and the relationship between collapse pressure and fault fractures, geostress, and formation pressure is established, improving the accuracy and reliability of wellbore stability. On the other hand, wellbore stability can be predicted without drilling, reducing the workload of drilling.

[0112] It should be understood that the embodiments disclosed herein are not limited to the specific structures, processing steps, or materials disclosed herein, but should be extended to equivalent substitutions of these features as understood by those skilled in the art. It should also be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting.

[0113] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0114] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0115] Certain terms are used throughout this application to refer to specific system components. As those skilled in the art will recognize, the same components may often be referred to by different names, and therefore this application is not intended to distinguish those components that differ only in name and not in function. In this application, the terms “comprise,” “include,” and “have” are used in an open-ended manner and should therefore be interpreted as meaning “including, but not limited to…”. Furthermore, the terms “substantially,” “materially,” or “approximately” as used herein refer to industry-accepted tolerances for the corresponding terms. The term “coupling,” as may be used herein, includes direct coupling and indirect coupling via additional components, elements, circuits, or modules, wherein, for indirect coupling, the intermediate component, element, circuit, or module does not alter the information of the signal but may adjust its current level, voltage level, and / or power level. Inferred coupling (e.g., one element is inferredly coupled to another element) includes direct and indirect coupling between two elements in the same manner as “coupling.”

[0116] The phrase "an embodiment" or "an embodiment" used in this specification means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. Therefore, the phrase "an embodiment" or "an embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment.

[0117] The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of the invention, and to enable those skilled in the art to understand the invention and to design various embodiments with various modifications suitable for a particular purpose.

[0118] While the embodiments disclosed in this invention are as described above, the content is merely for the purpose of facilitating understanding of the invention and is not intended to limit the invention. Any person skilled in the art to which this invention pertains may make any modifications and variations in form and detail of the implementation without departing from the spirit and scope disclosed herein; however, the scope of patent protection for this invention shall still be determined by the scope defined in the appended claims.

Claims

1. A method for predicting wellbore stability before drilling, characterized in that, The method includes: Acquire the 3D seismic data volume and seismic layer velocity of the area to be drilled, well logging interpretation data of adjacent wells, and determine the simulated well logging data of the well to be drilled; the adjacent wells are those adjacent to the well to be drilled. Based on the simulated logging data and the three-dimensional seismic data volume, a fracture structure model of the area to be drilled is established. Based on the fracture structure model, the well logging interpretation data, and the seismic layer velocity, a formation pressure model, a rock mechanical property model, and a geostress model are established for the area to be drilled. Based on the fracture structure model, the formation pressure model, the rock mechanical property model, and the geostress model, a finite element model of the area to be drilled is established. Finite element forward modeling is performed based on the finite element model to obtain the collapse pressure, thereby predicting the wellbore stability of the well to be drilled.

2. The method as described in claim 1, characterized in that, The crack structure model is constructed using the following steps: Based on the simulated logging data, a three-dimensional geological structure model of the area to be drilled is constructed. Based on the three-dimensional seismic data volume, a fracture distribution model of the area to be drilled is constructed; The fracture structure model is obtained by integrating the three-dimensional geological structure model and the fracture distribution model. The simulated well logging data includes geological structural data and seismic interpretation stratigraphic data.

3. The method as described in claim 2, characterized in that, The three-dimensional geological structure model is constructed using the following steps: Based on the simulated logging data, the formation data of the area to be drilled are determined; Interpolate the stratigraphic data to generate a stratigraphic plane; Based on the data from the adjacent wells, the strata are corrected, and the strata are divided into vertical and horizontal grids to construct the three-dimensional geological structure model.

4. The method as described in claim 2 or 3, characterized in that, The crack propagation model is constructed using the following steps: Ant tracking technology is used to identify faults and fractures in the three-dimensional seismic data volume in order to construct a fracture distribution model.

5. The method according to any one of claims 2-4, characterized in that, The well logging interpretation data includes: formation pressure, geostress, and rock mechanics parameters; The formation pressure model, the geostress model, and the rock mechanical property model are established through the following steps: The well logging interpretation data are coarsened to the fracture structure model respectively; In the fracture structure model, well logging interpretation data and seismic layer velocity are used as constraints to perform inter-well interpolation to establish the formation pressure model, the geostress model, and the rock mechanical property model accordingly. The rock mechanical property model includes: an elastic modulus property model, a Poisson's ratio property model, and a pore pressure property model.

6. The method as described in claim 5, characterized in that, The finite element model is established through the following steps: Based on the seismic interpretation stratigraphic data and the fault and fracture data in the fracture structure model, the geological geometric model of the area to be drilled is reconstructed. The fault planes and bedding planes of the geological geometric model are meshed, the maximum value and direction of the geostress in the formation pressure model are used as boundary conditions, and material properties are assigned based on the formation pressure model and the rock mechanical property model to establish the finite element model.

7. The method as described in claim 6, characterized in that, Assign material properties using the following steps: Data from the rock mechanics property model and the formation pressure model are extracted, and a three-dimensional interpolation function for the well perimeter region is constructed to assign material property values ​​to the finite element model.

8. The method according to any one of claims 1-7, characterized in that, The drilling area includes one of the following: shale formations, carbonate formations, and sandstone formations.

9. A storage medium, characterized in that, It includes a series of instructions for performing the method steps as described in any one of claims 1-8.

10. A pre-drilling wellbore stability prediction device, characterized in that, The apparatus for performing the method as described in any one of claims 1-8 comprises: The acquisition module is used to acquire the three-dimensional seismic data volume and seismic layer velocity of the area to be drilled, the logging interpretation data of adjacent wells, and to determine the simulated logging data of the well to be drilled; the adjacent wells are those adjacent to the well to be drilled. The first module is used to establish a fracture structure model of the area to be drilled based on the simulated logging data and the three-dimensional seismic data volume. The second module is used to establish a formation pressure model, a rock mechanical property model, and a geostress model for the area to be drilled, based on the fracture structure model, the well logging interpretation data, and the seismic layer velocity. The third module is used to establish a finite element model of the area to be drilled based on the fracture structure model, the formation pressure model, the rock mechanical property model, and the geostress model. The prediction module is used to perform finite element forward modeling based on the finite element model to obtain the collapse pressure, so as to predict the wellbore stability of the well to be drilled.

Images