Single-well multi-stage drilling equipment, drilling methods, devices, equipment and storage media

Abstract

This application provides a single-well multi-stage drilling equipment, drilling method, apparatus, equipment, and storage medium, relating to the field of oil and gas drilling technology. The equipment includes: a guide component, multiple drilling subs, multiple casings, multiple fixing components, and a suspension component, wherein: the guide component is connected to one end of the casing, and the suspension component is connected to the other end of the casing; the multiple casings are respectively connected to the multiple drilling subs and the multiple fixing components; the guide component is used to drive the single-well multi-stage drilling equipment into the first branch wellbore in the main wellbore; the drilling subs are used to drill the second branch wellbore from the first branch wellbore; the fixing components are used to fix the drilling subs to the casing, thereby increasing the oil and gas production of the single well.

Description

Technical Field

[0001] This application relates to the field of oil and gas drilling technology, and in particular to a single-well multi-stage drilling equipment, drilling method, apparatus, equipment and storage medium. Background Technology

[0002] In the process of developing single-well oil and gas, the maximum reservoir contact (MRC) technology is usually used to increase the production of a single well.

[0003] In related technologies, a wellbore structure of "main wellbore + branch wellbore" is usually adopted, in which the branch wellbore is formed by side-drilling at a specific depth position of the main wellbore.

[0004] However, in the above methods, the contact area between the wellbore structure and the oil and gas reservoir is relatively limited, which restricts the further improvement of single-well productivity. Summary of the Invention

[0005] This application provides a single-well multi-stage drilling equipment, drilling method, apparatus, equipment, and storage medium to solve the problem of low oil and gas production in single wells.

[0006] In a first aspect, this application provides a single-well multi-stage drilling rig, comprising: a guiding component, multiple drilling subs, multiple casings, multiple fixing components, and a suspension component, wherein:

[0007] The guide component is connected to one end of the sleeve, and the suspension component is connected to the other end of the sleeve;

[0008] Multiple casings are connected to multiple drilling subs and multiple fixing components, respectively;

[0009] The guide component is used to drive the single-well multi-stage drilling equipment into the first branch wellbore in the main wellbore;

[0010] The sub-sub is used to drill the second branch wellbore from the first branch wellbore.

[0011] The retaining component is used to secure the drilled sub to the casing.

[0012] In one possible implementation, the drilling sub includes multiple drilling components and control devices, wherein:

[0013] The control device is used to control the drilling components to drill into the second branch wellbore along the drilling track in the first branch wellbore;

[0014] The number of drilling components in each drilling sub is greater than or equal to 2.

[0015] In one possible implementation, the guiding component includes a reentry tool and a floating shoe device, wherein:

[0016] The float shoe device is set in the direction of the guide component toward the first branch wellbore. One end of the re-entry tool is connected to the float shoe device, and the other end of the re-entry tool is connected to the first casing, which is the farthest casing.

[0017] The reentry tool is used to rotate and guide a single-well multi-stage drilling rig into the first branch wellbore.

[0018] The float shoe device is used to control the flow rate of drilling fluid at the farthest drilling sub, which is connected to the first casing.

[0019] In one possible implementation, multiple casings, multiple drill bits, and multiple fixing components are interconnected in an alternating manner.

[0020] Secondly, this application provides a single-well multi-stage drilling method, including:

[0021] Determine the first flow rate of each drilling sub in a single-well multi-stage drilling rig, where the first flow rate is the flow rate of drilling fluid in the drilling sub;

[0022] Based on multiple first flow rates, determine the second flow rate inside the casing corresponding to the target drilling sub, which is the farthest drilling sub.

[0023] Based on the second flow rate, control each drilling sub and drill multiple second branch wells in the first branch well.

[0024] In one possible implementation, determining the first flow rate of each drilled sub in a multi-stage drilling rig for a single well includes:

[0025] Obtain the first pressure inside the casing and the second pressure outside the casing for multiple drilled subs.

[0026] Obtain the first flow resistance of multiple drilled short sections;

[0027] Based on multiple first pressures, multiple second pressures, and multiple first flow resistances, the first flow rate of multiple drilled subs is determined.

[0028] In one possible implementation, for any given drilled sub, a first flow rate of a plurality of drilled subs is determined based on a plurality of first pressures, a plurality of second pressures, and a plurality of first flow resistances, including:

[0029] Determine the first pressure difference between the first pressure and the second pressure corresponding to the drilling sub;

[0030] The ratio of the first pressure difference to the first flow resistance is determined as the first flow rate when drilling into the short section.

[0031] In one possible implementation, obtaining a first pressure within the casing and a second pressure outside the casing for the plurality of drilled subs includes:

[0032] For the i-th drilled section;

[0033] Obtain the first pressure and the first pressure loss corresponding to the (i-1)th drilling section. The (i-1)th pressure loss is the pressure loss generated when the flow of the (i-1)th drilling section flows into the ith drilling section.

[0034] The difference between the first pressure corresponding to the (i-1)th drilled section and the (i-1)th pressure loss is determined as the first pressure corresponding to the i-th drilled section.

[0035] Obtain the second pressure and the pressure loss corresponding to the (i+1)th drilled section;

[0036] The difference between the second pressure corresponding to the (i+1)th drilled section and the pressure loss of the (i+1)th drilled section is determined as the second pressure corresponding to the i-th drilled section.

[0037] Where i takes the values ​​2, 3, ..., N in sequence, and N is the total number of short sections drilled in.

[0038] In one possible implementation, determining a second flow rate within the casing corresponding to the target drilled sub section based on a plurality of first flow rates includes:

[0039] Obtain the second flow rate in the casing corresponding to the previous drilling sub-segment of the target drilling sub-segment;

[0040] The sum of the first flow rates corresponding to multiple drilled subs is determined to obtain the third flow rate;

[0041] The difference between the second flow rate and the third flow rate is determined as the second flow rate inside the casing corresponding to the target drilled sub.

[0042] Thirdly, this application provides a single-well multi-stage drilling apparatus, comprising: a first determining module, a second determining module, and a processing module, wherein:

[0043] The first determining module is used to determine the first flow rate of each drilling sub in a single-well multi-stage drilling rig, wherein the first flow rate is the flow rate of drilling fluid in the drilling sub;

[0044] The second determining module is used to determine the second flow rate in the casing corresponding to the target drilling sub, based on multiple first flow rates, wherein the target drilling sub is the farthest drilling sub.

[0045] The processing module is used to control each drilling sub to drill multiple second branch wells in the first branch wellbore, based on the second flow rate.

[0046] In one possible implementation, the first determining module is specifically used for:

[0047] Obtain the first pressure inside the casing and the second pressure outside the casing for multiple drilled subs.

[0048] Obtain the first flow resistance of multiple drilled short sections;

[0049] Based on multiple first pressures, multiple second pressures, and multiple first flow resistances, the first flow rate of multiple drilled subs is determined.

[0050] In one possible implementation, the first determining module is specifically used for:

[0051] Determine the first pressure difference between the first pressure and the second pressure corresponding to the drilling sub;

[0052] The ratio of the first pressure difference to the first flow resistance is determined as the first flow rate when drilling into the short section.

[0053] In one possible implementation, the first determining module is specifically used for:

[0054] For the i-th drilled section;

[0055] Obtain the first pressure and the first pressure loss corresponding to the (i-1)th drilling section. The (i-1)th pressure loss is the pressure loss generated when the flow of the (i-1)th drilling section flows into the ith drilling section.

[0056] The difference between the first pressure corresponding to the (i-1)th drilled section and the (i-1)th pressure loss is determined as the first pressure corresponding to the i-th drilled section.

[0057] Obtain the second pressure and the pressure loss corresponding to the (i+1)th drilled section;

[0058] The difference between the second pressure corresponding to the (i+1)th drilled section and the pressure loss of the (i+1)th drilled section is determined as the second pressure corresponding to the i-th drilled section.

[0059] Where i takes the values ​​2, 3, ..., N in sequence, and N is the total number of short sections drilled in.

[0060] In one possible implementation, the second determining module is specifically used for:

[0061] Obtain the second flow rate in the casing corresponding to the previous drilling sub-segment of the target drilling sub-segment;

[0062] The sum of the first flow rates corresponding to multiple drilled subs is determined to obtain the third flow rate;

[0063] The difference between the second flow rate and the third flow rate is determined as the second flow rate inside the casing corresponding to the target drilled sub.

[0064] Fourthly, embodiments of this application provide an electronic device, including: at least one processor and a memory; the memory stores computer-executable instructions; the at least one processor executes the computer-executable instructions stored in the memory, causing the at least one processor to perform the single-well multi-stage drilling method as described in the second aspect above and any of the second aspects.

[0065] Fifthly, embodiments of this application provide a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the single-well multi-stage drilling method described in the second aspect above and any of the second aspects.

[0066] Sixthly, embodiments of this application provide a computer program product, including a computer program that, when executed by a processor, implements the single-well multi-stage drilling method as described in the second aspect above and any of the second aspects.

[0067] The single-well multi-stage drilling equipment, drilling method, apparatus, equipment, and storage medium provided in this application, when drilling is required, can include a guide component, multiple drilling subs, multiple casings, multiple fixing components, and a suspension component, wherein: the guide component is connected to one end of the casing, and the suspension component is connected to the other end of the casing; multiple casings are respectively connected to multiple drilling subs and multiple fixing components; the guide component is used to drive the single-well multi-stage drilling equipment to enter the first branch wellbore in the main wellbore; the drilling subs are used to drill the second branch wellbore in the first branch wellbore; and the fixing components are used to fix the drilling subs to the casing. In the above structure, the single-well multi-stage drilling equipment can sequentially form the first branch wellbore and the second branch wellbore based on the main wellbore, that is, establish a multi-stage wellbore network. Compared with the traditional single wellbore or two-level branch structure, it can significantly expand the contact area with the oil and gas reservoir, increase the controlled volume of the single-well oil and gas reservoir, and thus improve the oil and gas production of the single well. Attached Figure Description

[0068] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0069] Figure 1 This application provides a schematic diagram of the structure of a single-well multi-stage drilling equipment.

[0070] Figure 2 This is a schematic diagram of the structure of a three-section horizontal well provided in an embodiment of this application;

[0071] Figure 3 A schematic diagram illustrating the distribution of multiple single-well multi-stage drilling rigs provided in an embodiment of this application;

[0072] Figure 4 This application provides a schematic diagram of another single-well multi-stage drilling equipment.

[0073] Figure 5 This is a schematic diagram of the structure of the well completion string equipment provided in the embodiments of this application;

[0074] Figure 6 This is a schematic diagram of the structure of a single well provided in an embodiment of this application;

[0075] Figure 7 This application provides a schematic diagram of a single-well multi-stage drilling method according to an embodiment of the present application.

[0076] Figure 8 A schematic diagram illustrating the process of determining the first flow rate of each drilled sub section provided in the embodiments of this application;

[0077] Figure 9 A schematic diagram of another single-well multi-stage drilling method provided in this application embodiment;

[0078] Figure 10 This is a schematic diagram of the structure of a single-well multi-stage drilling device provided in an embodiment of this application;

[0079] Figure 11 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application.

[0080] Explanation of reference numerals in the attached figures:

[0081] 100-Single-well multi-stage drilling equipment;

[0082] 101 - Guide component;

[0083] 102 - Drill into the short section;

[0084] 103-Casing;

[0085] 104 - Fixed components;

[0086] 105 - Suspension components;

[0087] 106 - Main wellbore;

[0088] 107 - First branch wellbore;

[0089] 108 - Second branch wellbore;

[0090] 109 - Surface sleeve;

[0091] 110-Technical Sleeve;

[0092] 111 - First sleeve;

[0093] 1011 - Reentrancy Tool;

[0094] 1012 - Floating shoe device;

[0095] 1021 - Drilling components;

[0096] 1022 - Control device.

[0097] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0098] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0099] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in one or more embodiments of this specification are all information and data authorized by the user or fully authorized by all parties. Furthermore, the collection, use and processing of related data must comply with relevant laws, regulations and standards, and corresponding operation entry points are provided for users to choose to authorize or refuse.

[0100] It should be noted that in the embodiments of this application, certain software, components, models and other existing solutions in the industry may be mentioned. These should be regarded as exemplary and are only intended to illustrate the feasibility of implementing the technical solution of this application. However, it does not mean that the applicant has used or necessarily used the solution.

[0101] In related technologies, a wellbore structure of "main wellbore + branch wellbore" is typically adopted, in which the branch wellbore is sidetracked at a specific depth from the main wellbore. However, in this method, the contact area between the wellbore structure and the oil and gas reservoir is relatively limited, which restricts further improvement in single-well productivity.

[0102] To address the aforementioned issues, in this embodiment, when drilling is required, the single-well multi-stage drilling equipment includes a guide component, multiple drilling subs, multiple casings, multiple fixing components, and a suspension component. The guide component drives the single-well multi-stage drilling equipment to enter the first branch wellbore within the main wellbore. The drilling subs are used to drill the second branch wellbore from the first branch wellbore. In this structure, due to the hierarchical design of the guide component and multiple drilling subs in the single-well multi-stage drilling equipment, the single-well multi-stage drilling equipment can sequentially form the first and second branch wellbores based on the main wellbore, thus establishing a multi-stage well of "main wellbore - branch wellbore - micro wellbore". Compared to traditional single-well or two-branch structures, the eye network can significantly expand the contact area with the oil and gas reservoir, achieving a significant increase in the volume of oil and gas flow control within the same limited space. Furthermore, the terminal equipment can calculate the flow rate of each drilled sub based on the pressure difference inside and outside the casing, ensuring that the farthest drilled sub can obtain sufficient drilling power during the drilling process, thereby achieving synchronous batch drilling of the second branch well. In this case, the terminal equipment, through the combination of single-well multi-level drilling equipment and drilling methods, can be applied to the exploitation needs of different oil and gas reservoir conditions. Thus, the embodiments of this application improve drilling efficiency and increase the oil and gas production of a single well.

[0103] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will be described below with reference to the accompanying drawings.

[0104] Figure 1 This is a structural schematic diagram of a single-well multi-stage drilling rig provided as an embodiment of this application. Please refer to... Figure 1 As shown, the single-well multi-stage drilling equipment 100 provided in this application embodiment includes a guide component 101, multiple drilling subs 102, multiple casings 103, multiple fixing components 104, and a suspension component 105, wherein:

[0105] The guide component 101 is connected to one end of the sleeve 103, and the suspension component 105 is connected to the other end of the sleeve 103.

[0106] In some embodiments, the guide member 101 may be disposed at the top of the single-well multi-stage drilling equipment 100, so that the guide member 101 can guide the single-well multi-stage drilling equipment 100 into the wellbore.

[0107] Multiple casings 103 are respectively connected to multiple drilling subs 102 and multiple fixing components 104.

[0108] In some embodiments, the casing 103 can be used to fix multiple components, that is, the casing 103 can fix the guide component 101, multiple drilling subs 102, multiple fixing components 104 and suspension components 105. For example, the casing 103 can be a screen pipe. Furthermore, the casing 103 can also be used to provide a flow channel for drilling fluid, that is, drilling fluid can be delivered to the guide component 101 and multiple drilling subs 102, thereby providing power for drilling into the wellbore.

[0109] Multiple casings 103, multiple drilling subs 102, and multiple fixing components 104 are connected in an alternating manner.

[0110] In some embodiments, the component positions of a single-well multi-stage drilling rig 100 can be determined by grouping, that is, multiple casings 103, multiple drilling subs 102 and multiple fixing components 104 on the single-well multi-stage drilling rig 100 are arranged in a grouping order.

[0111] For example, if each group includes two drill bits 102 and one fixing component 104, the arrangement of the structure can be (drill bit - drill bit - fixing component), wherein these components are connected by a sleeve 103, that is, the arrangement of the structure can be (drill bit - sleeve - drill bit - sleeve - fixing component). After obtaining multiple groups of the above structures, any two groups of structures are connected by a sleeve, and the arrangement of the structure can be (drill bit - sleeve - drill bit - sleeve - fixing component) - sleeve - (drill bit - sleeve - drill bit - sleeve - fixing component). Each group of structures includes at least one drill bit 102 and one fixing component 104.

[0112] In some embodiments, the component positions of a single-well multi-stage drilling rig 100 can be determined by an interval arrangement. That is, multiple casings 103, multiple drilling subs 102, and multiple fixing components 104 on the single-well multi-stage drilling rig 100 are arranged at preset intervals. For example, the arrangement of the structure can be (drilling sub-casing-fixing component-casing-drilling sub-casing-fixing component-...). In this way, by alternating the connection of drilling subs 102, casings 103, and fixing components 104, the oil and gas discharge channels are maximized, thereby increasing the oil and gas production of a single well.

[0113] In some embodiments, the terminal equipment can determine the arrangement of multiple casings 103, multiple drilling subs 102, and multiple fixing components 104 based on the oil layer parameters of a single well (e.g., the length of the oil layer section). For example, if the oil layer section in the area is long, the number of drilling subs 102 corresponding to the area can be increased. If the oil layer section in the area is short or the area is a non-reservoir area, the number of drilling subs 102 corresponding to the area can be reduced or no drilling subs 102 can be set. In this way, the waste of components in ineffective formations can be effectively avoided, and drilling costs can be saved.

[0114] The guide component 101 is used to drive the single-well multi-stage drilling equipment 100 into the first branch wellbore 107 in the main wellbore 106.

[0115] The sub 102 is used to drill the second branch wellbore 108 from the first branch wellbore 107.

[0116] The fixing component 104 is used to fix the drilled sub 102 to the casing 103.

[0117] In some embodiments, the fixing component 104 can be an anchor. In this application embodiment, an open-hole anchor can be used as the fixing component 104, which can play the role of positioning and cementing the well string, ensuring that the well string does not shift due to stress during construction and production.

[0118] In some embodiments, the suspension component 105 can be a branch wellhead suspension support tool, so that the suspension component 105 can be fixedly supported near the wellhead of the branch well, serving to support the well wall and suspend the fixed pipe string (single well multi-stage drilling equipment 100).

[0119] In some embodiments, the working mode of the guide component 101 can be hydraulically driven. Specifically, after the single-well multi-stage drilling equipment 100 enters the main wellbore 106, the position of the single-well multi-stage drilling equipment 100 can be determined by a display device, such as the depth data of the single-well multi-stage drilling equipment 100 entering the main wellbore 106. After determining that the entry depth of the single-well multi-stage drilling equipment 100 meets the requirements, the drilling fluid circulation pump is turned on, and the guide component 101 can enter the first branch wellbore 107 under the drive of the drilling fluid.

[0120] Below, in conjunction with Figure 2 The structure of a three-section horizontal well is explained through specific examples.

[0121] Figure 2 For a structural schematic diagram of the three-section horizontal well provided in the embodiments of this application, please refer to [link / reference]. Figure 2It includes a main wellbore 106, multiple first branch wellbores 107 and multiple second branch wellbores 108, a surface casing 109 and a technical casing 110, wherein the size of the first branch wellbore 107 is smaller than that of the main wellbore 106, and the size of the second branch wellbore 108 is smaller than that of the main wellbore 106.

[0122] like Figure 2 As shown, the first branch wellbore 107 is formed on the basis of the main wellbore 106, and the second branch wellbore 108 is formed on the basis of the first branch wellbore 107. That is, multiple first branch wellbores 107 are drilled on the side of the main wellbore 106, and multiple second branch wellbores 108 are drilled on the side of each first branch wellbore 107.

[0123] In some embodiments, the first branch wellbore 107 can be formed as follows: Based on the geological conditions surrounding the main wellbore 106, the number and location of the first branch wellbore 107 are determined; based on the main wellbore 106, using sidetracking tools, multiple first branch wellbores 107 are sequentially formed from the bottom of the well upwards. If there are four first branch wellbores 107 along the bottom of the well, namely first branch wellbore 1, first branch wellbore 2, first branch wellbore 3, and first branch wellbore 4, then the drilling sequence is first branch wellbore 4, first branch wellbore 3, first branch wellbore 2, and first branch wellbore 1. After drilling each first branch wellbore 107, a gel-type protective fluid needs to be injected. This helps maintain wellbore stability and protect the reservoir, providing long-term stability, maintaining a solidified or semi-solidified state, and allowing for flushing and circulation by the down-the-loop tools.

[0124] In some embodiments, the second branch wellbore 108 can be formed in the following manner: the single-well multi-stage drilling equipment 100 is guided by the guide component 101 to drill into the first branch wellbore 107. After the single-well multi-stage drilling equipment 100 is determined to be in place, branch holes are drilled in batches at various positions in the first branch wellbore 107 to form multiple second branch wellbores 108.

[0125] Below, in conjunction with Figure 3 The distribution of multiple single-well, multi-stage drilling equipment is illustrated through specific examples.

[0126] Figure 3 For a schematic diagram illustrating the distribution of multiple single-well multi-stage drilling rigs provided in this application embodiment, please refer to [link / reference]. Figure 3 It includes four first branch wellbores 107, and multiple second branch wellbores 108 can be drilled in the first branch wellbores 107 in a sequence from bottom to top through the single-well multi-stage drilling equipment 100.

[0127] In this embodiment, when drilling is required, the single-well multi-stage drilling equipment includes a guide component, multiple drilling subs, multiple casings, multiple fixing components, and a suspension component. The guide component drives the single-well multi-stage drilling equipment to enter the first branch wellbore in the main wellbore. The drilling subs are used to drill the second branch wellbore out of the first branch wellbore. In the above structure, due to the hierarchical design of the guide component and multiple drilling subs in the single-well multi-stage drilling equipment, the single-well multi-stage drilling equipment can sequentially form the first branch wellbore and the second branch well based on the main wellbore. The term "eye" refers to establishing a multi-level wellbore network consisting of "main wellbore - branch wellbore - micro wellbore". Compared with traditional single wellbore or two-level branch structures, it can significantly expand the contact area with oil and gas reservoirs, and significantly improve the volume of oil and gas flow control within the same limited space, thereby increasing the oil and gas production of a single well. Furthermore, by fixing the drilled sub to the casing with fixed components, the stability of the equipment during drilling can be ensured in conjunction with the support of the casing, avoiding wellbore trajectory deviation caused by the displacement of the drilled sub, and improving the safety and stability of multi-level drilling equipment for single wells.

[0128] Based on any of the above embodiments, the following, in conjunction with Figure 4 This section provides a detailed description of multi-stage drilling equipment for single wells.

[0129] Figure 4 This application provides a structural schematic diagram of another single-well multi-stage drilling equipment. Please refer to [link / reference]. Figure 4 The drilling sub 102 includes multiple drilling components 1021 and a control device 1022.

[0130] The control device 1022 is used to control the drilling component 1021 to drill the second branch wellbore 108 in the first branch wellbore 107 along the drilling track.

[0131] The number of drilling components 1021 in each drilling sub 102 is greater than or equal to 2.

[0132] In some embodiments, the control device 1022 can apply a certain lateral force to the drilling component 1021 during the initial stage of drilling into the formation, thereby adjusting the initial shape of the second branch wellbore 108 (e.g., the rate of change of the full angle), and thus controlling the drilling component 1021 to drill out of the second branch wellbore 108.

[0133] In some embodiments, the control device 1022 prevents the drill bit in the drilling component 1021 from getting stuck on the well wall by blocking the drilling component 1021 from drilling out of the guide hole.

[0134] In some embodiments, the drilling components 1021 are evenly distributed circumferentially on the sidewall of the drilling sub 102. If the number of drilling components 1021 in the drilling sub 102 is 2, the drilling components 1021 are respectively located on both sides of each drilling sub 102, so that the drilling sub 102 can drill 2 second branch wells 108 simultaneously. If the number of drilling components 1021 in the drilling sub 102 is greater than 2, the drilling components 1021 are evenly distributed at a certain angle on the sidewall of the drilling sub 102. For example, if the number of drilling components 1021 in the drilling sub 102 is 3, the drilling components 1021 are evenly distributed at 120 degrees on the sidewall of the drilling sub 102, so that the drilling sub can drill 3 second branch wells 108 simultaneously.

[0135] In some embodiments, the drilling sub 102 also includes a drive mechanism (e.g., an impeller). Specifically, the drilling sub 102 can be hydraulically driven by a drive device to enable the drilling sub 102 to drill more than two microholes simultaneously, and to ensure that the drive mechanism reaches and maintains the minimum drilling flow rate.

[0136] In some embodiments, the drilling sub 102 also includes a pressure change mechanism. Specifically, when drilling the second branch wellbore 108, if the drilling component 1021 reaches a preset well depth, it triggers the pressure change mechanism in the drilling sub 102, causing a sudden change in the pressure inside the pipe. In this way, the final position of the second branch wellbore 108 can be accurately determined based on the pressure change signal, thereby improving drilling efficiency.

[0137] The guide component 101 includes a re-entry tool 1011 and a floating shoe device 1012.

[0138] The float shoe device 1012 is arranged in the direction of the guide component 101 toward the first branch wellbore 107. One end of the re-entry tool 1011 is connected to the float shoe device 1012, and the other end of the re-entry tool 1011 is connected to the first casing 111, which is the farthest casing.

[0139] The reentry tool 1011 is used to rotate and guide the single-well multi-stage drilling equipment 100 into the first branch wellbore 107.

[0140] The float shoe device 1012 is used to control the flow rate of drilling fluid at the furthest drilling sub 102.

[0141] The furthest drilling sub 102 is connected to the first casing 111.

[0142] In some embodiments, the guidance process of the hydraulically driven re-entry tool is as follows: after the re-entry tool is lowered to a certain distance below the first branch wellbore 107, the drilling fluid circulation pump is turned on for circulation. When the current displacement exceeds the starting displacement of the re-entry tool 1011, the guide part of the hydraulically driven re-entry tool 1011 forms a certain bend angle, which can flexibly contact the well wall and achieve 360-degree circumferential rotation detection. When the re-entry tool 1011 is slowly lifted up to the port of the single-well multi-stage drilling equipment 100 to the first branch wellbore 107, the re-entry tool 1011 extends into the first branch wellbore 107 under hydraulic drive. At the same time, the internal pressure relief hole is opened, which causes the pressure inside the casing of the single-well multi-stage drilling equipment 100 to drop, thereby indicating that it has entered the first branch wellbore 107.

[0143] In some embodiments, the float shoe device 1012 can be combined with the re-entry tool 1011. The float shoe device 1012 can be connected to the upper end of the re-entry tool 1011, and the float shoe device 1012 includes a flow resistance control component, that is, dynamically changing the flow resistance by adjusting the size of the flow orifice. For example, the smaller the size of the flow orifice, the greater the flow resistance inside the pipe, thereby adjusting the flow pressure difference of the drilling fluid inside and outside the tubing string (single-well multi-stage drilling equipment 100). In this way, the float shoe device 1012 can work with the re-entry tool 1011 to control the flow rate and pressure difference inside and outside the casing. It can also be used in conjunction with batch micro-well drilling technology to adjust the appropriate flow rate and pressure difference in advance to meet the construction parameters of the farthest micro-well drilling sub. Before entering the well, the construction parameters are calculated, and the flow resistance control structure element is set on the surface according to the calculation results.

[0144] In some embodiments, single-well multi-level wellbore network drilling can be either new drilling or sidetracking of old wells. The core of both is to form a three-level wellbore network through drilling, namely, the first-level main wellbore 106, the second-level first branch wellbore 107, and the third-level second branch wellbore 108.

[0145] In some embodiments, after the single-well multi-stage drilling equipment 100 is lowered into place, the process of batch drilling three-stage second branch wellbores 108 is as follows: the single-well multi-stage drilling equipment 100 is fixed at a specific position in the well by a ball-dropping pressure-blocking seat hanger, and the position is locked by radial expansion of the seat open hole anchor. After the flow resistance regulation of the float shoe device 1012 reaches the preset pressure difference condition, the drilling components 1021 of each drilling sub 102 are opened for batch drilling to form multiple second branch wellbores 108. After replacing the completion protection fluid to stabilize the second branch wellbores 108, the delivery tool is disengaged so that the single-well multi-stage drilling equipment 100 is independently suspended. The seat-mounted branch wellhead suspension support tool also includes a top packer, which can form a seal in the space between the casing and the well wall annulus. After the packer is inspected and found to be qualified, the single-well multi-stage drilling equipment 100 is pulled out. If multiple second branch wellbores 108 need to be drilled simultaneously, the above process should be carried out in a cyclical manner from the bottom of the well to the wellhead to avoid contamination of the lower wellbores.

[0146] In some embodiments, a micro drill bit is selected based on the lithology of the formation to ensure that the drill bit does not fail while drilling to a set depth. Each drilling component 1021 of the drilling sub 102 has an anti-interference design to prevent interference during batch drilling.

[0147] In some embodiments, when dealing with problems such as excessive drilling pressure or excessive flow rate caused by excessive well depth, complex well structure, or too many micro-well drilling subs, multiple drilling subs 102 deployed on a single-well multi-stage drilling rig 100 are grouped and drilled in the order of grouping to form multiple second branch wellbores 108. After drilling a single group of drilling subs, the internal pressure change structure is controlled to switch to a throttling or flow interruption state. This reduces the flow distribution of the drilled drilling subs 102, reduces energy consumption, optimizes energy resources, and thus improves the overall drilling efficiency.

[0148] For example, if it is necessary to form multiple second branch wellbores 108 based on the first branch wellbore 107 using 50 drilling subs 102, they can be divided into several groups, for example, 5 groups. Drilling operations can then be carried out sequentially according to the group order. First, the 10 drilling subs 102 in the first group are drilled in batches. After the corresponding second branch wellbore 108 is drilled into place, the pressure change structure is used to set it to a throttling or flow interruption state, without needing to allocate flow to the drilling subs 102 in this group. This process continues until the second branch wellbore 108 of the drilling subs 102 in the fifth group is drilled into place. In this case, this grouping method can effectively reduce the pressure and flow rate requirements during drilling of a single group, avoid equipment wear or reduced operating efficiency due to excessive overall load, achieve energy consumption optimization, and improve the stability and economy of the overall operation.

[0149] In some embodiments, after the second branch wellbore 108 is drilled, a completion string device 200 needs to be installed and placed inside the main wellbore 106 to achieve communication with each of the first branch wellbores 107.

[0150] Below, in conjunction with Figure 5 The structure of the well completion string equipment is explained through specific examples.

[0151] Figure 5 For a structural schematic diagram of the well completion string equipment provided in the embodiments of this application, please refer to [link / reference]. Figure 5 It includes a hanger 201, a completion casing 202, a centralizer 203, a positioning and connecting sleeve 204, a screen pipe 205, and a float shoe type well washing valve 206.

[0152] The positioning and connecting sleeve 204 is used to connect the main wellbore and each of the first branch wellbores. Specifically, after well completion, the matching positioning and connecting sleeve 204 needs to be lowered and opened. The positioning can be achieved by the measurement system inside the special tool to determine the port of each first branch wellbore 107 in the main wellbore 106, so that the opening of the positioning and connecting sleeve 204 is aligned with the first branch wellbore 107.

[0153] In some embodiments, the completion string equipment 200 further includes an open-hole packer, a top packer, and a delivery tool. Specifically, when constructing the completion string, the installation position of the connecting sliding sleeve must be calculated to ensure that the completion string equipment is in a connectable position with the corresponding second-level first branch wellbore 107 after it is in place. Furthermore, the installation position and quantity of the completion casing 202 and screen pipe 205 must be calculated based on the formation profile. The completion casing 202 and screen pipe 205 must be determined according to geological and production requirements. If the screen pipe is not required, a guide hole mechanism can be installed on the completion casing 202. If segmentation is required, an open-hole packer can be added to the completion string equipment 200.

[0154] In some embodiments, well completion operations can be performed as follows: The assembled completion string 200 is lowered to the bottom of the main wellbore 106. After correcting the well depth reference, the tubing string is fixed using the hanger 201, and the open-hole packer is used to isolate the sections. The delivery tool and the completion string 200 are then separated, and the casing is released. Subsequently, the top packer is used to seal the completion casing 202 and the annulus of the wellbore. A pressure test is conducted to verify the seal. After confirming that the packer is leak-free, the drill string is pulled out, and the positioning connecting sleeve 204 is lowered into the wellbore using the tool. The built-in measurement system of the tool precisely locates the position of each positioning connecting sleeve 204, ensuring that the opening of the positioning connecting sleeve 204 is precisely aligned with each of the first branch wellbores 107 in sequence. The well completion operation is completed after the drill string is pulled out. Before lowering the completion string 200, wellbore preparation and well cleaning operations must be performed to ensure that the wellbore is clean and unobstructed.

[0155] Below, in conjunction with Figure 6 The structure of a single well is explained through specific examples.

[0156] Figure 6 For a structural schematic diagram of a single well provided in the embodiments of this application, please refer to [link / reference]. Figure 6 It includes a surface casing, a technical casing, a main wellbore 106, multiple first branch wellbores 107, multiple second branch wellbores 108, multiple single-well multi-stage drilling rigs 100, and a completion string rig 200. The single-well multi-stage drilling rigs 100 are respectively installed in multiple first branch wellbores 107. The completion string rig 200 is installed inside the main wellbore 106 after passing through the surface casing and the technical casing. The guide component 101 is exemplified by the combination of a re-entry tool 1011 and a float shoe device 1012.

[0157] In some embodiments, the process of drilling a multi-level well network in a single well is as follows: First, a first-level main wellbore 106 is formed; second, multiple second-level first branch wellbores 107 are formed based on the first-level main wellbore 106; third, a single-well multi-level drilling rig 100 is installed; fourth, multiple third-level second branch wellbores 108 are formed based on the second-level first branch wellbores 107 using the single-well multi-level drilling rig 100; fifth, a completion string device 200 is installed; and sixth, the completion operation is completed using the completion string device 200.

[0158] In this embodiment, the drilling sub includes multiple drilling components and a control device. The control device controls the drilling components to drill a second branch wellbore along the drilling trajectory in the first branch wellbore. The number of drilling components in each drilling sub is greater than or equal to two. The guiding components include a re-entry tool and a float shoe device. In the above structure, the single-well multi-stage drilling equipment can precisely control the drilling trajectory of multiple drilling components through the control device, and through the synergistic effect of the re-entry tool guidance and the float shoe device dynamically adjusting the flow rate, a single-well three-dimensional well network is formed. This can significantly expand the contact area with the oil and gas reservoir, increase the control volume of the single-well oil and gas reservoir, thereby increasing the oil and gas production of the single well. Furthermore, it can be based on... Multiple secondary branch wellbores are formed by the synchronous operation of multiple drilling components, which improves drilling efficiency. Through the synergistic action of re-entry tools and float shoes, precise re-entry into complex wellbores and precise control of the pressure difference inside and outside the casing can be achieved, ensuring stable drilling pressure in each branch wellbore and significantly improving drilling efficiency. Furthermore, by using the positioning and connecting sleeve in the completion string equipment, the flow channels between each branch wellbore and the main wellbore can be precisely established after completion, maximizing the expansion of oil and gas production paths. This method meets the drilling needs of different reservoir scenarios, especially oil and gas reservoirs where fracturing technology is limited and economic mobilization is poor. It is applicable to drilling needs of different well depths and formation conditions.

[0159] Based on any of the above embodiments, the following, in conjunction with Figure 7 This paper provides a detailed explanation of the multi-stage drilling method for single wells.

[0160] Figure 7 This is a schematic diagram illustrating a single-well multi-stage drilling method provided in an embodiment of this application. Please refer to... Figure 7 The method may include:

[0161] S701. Determine the first flow rate of each drilling sub in a multi-stage drilling rig for a single well.

[0162] The first flow rate is the flow rate of drilling fluid in the drilling sub.

[0163] In some embodiments, before drilling the first branch wellbore, electronic equipment can determine the number and location of the first branch wellbore based on geological information, for example, by identifying oil and water layers through gamma resistivity curves.

[0164] Among them, geological information can be the logging data of the main wellbore, which can specifically include wellbore geometric parameters (e.g., diameter, inclination angle, etc.), geological parameters (e.g., gamma curve, resistivity curve, formation porosity, permeability), and logging interpretation results (e.g., the distribution depth and thickness of oil, water and gas layers).

[0165] Optionally, the electronic device can acquire a three-dimensional geometric model associated with the single well area based on the geographic information of the single well area. The three-dimensional geometric model can indicate the geological information of each area. In this way, the electronic device can determine the number and location of the first branch wellbore based on the three-dimensional geometric model.

[0166] In some embodiments, prior to drilling the second branch wellbore, the electronic equipment can determine the number of drilled subs and the interval between each drilled sub based on the length and thickness of the oil layer.

[0167] In some embodiments, after determining the number and location of the drilled subs, a multi-stage drilling rig can be assembled for a single well. Specifically, the drilled subs can be arranged at intervals from the proximal end to the distal end of the casing. Since the pressure inside the casing gradually decreases from the proximal end to the distal end, while the pressure outside the casing (annular pressure) gradually decreases from the distal end to the proximal end, the pressure difference between the inside and outside of the casing gradually decreases from the proximal end to the distal end, resulting in the lowest flow rate at the distal second branch wellbore.

[0168] In some embodiments, the electronic device can acquire the pressure values ​​inside and outside the casing corresponding to each drilling sub and determine the first flow rate of each drilling sub in a single-well multi-stage drilling rig based on the flow resistance of each drilling sub.

[0169] S702. Based on multiple first flow rates, determine the second flow rate inside the casing corresponding to the target drilling sub.

[0170] The target drilling sub is the furthest drilling sub.

[0171] In some embodiments, the electronic device may determine the second flow rate in the casing corresponding to each drilling sub section based on the flow conservation law, until the second flow rate of the target drilling sub section (farthest end) is determined.

[0172] In some embodiments, in order to achieve synchronous drilling of all second branch wellbores, a minimum flow rate threshold can be set. If the flow rate of the farthest target drilled sub is greater than or equal to the minimum flow rate threshold, it indicates that all drilled subs can be drilled into the second branch wellbore, and drilling operations can begin. If the flow rate of the farthest target drilled sub is less than the minimum flow rate threshold, it indicates that some drilled subs cannot be drilled into the second branch wellbore, and it is necessary to adjust and increase the available flow rate of the drilled subs to meet the minimum flow rate threshold, after which drilling operations can begin.

[0173] S703. Based on the second flow rate, control each drilling sub to drill multiple second branch wells in the first branch well.

[0174] In some embodiments, a minimum starting flow rate can be set, which needs to be determined through multiple ground tests. That is, the electronic equipment can determine whether each drilling sub is greater than or equal to the minimum starting flow rate based on the minimum starting flow rate. In particular, the second flow rate of the target drilling sub is greater than or equal to the minimum starting flow rate. If the requirements are met, the drilling sub is controlled to drill the second branch wellbore in the first branch wellbore based on the second flow rate. If the requirements are not met, the second flow rate of each drilling sub is readjusted until the requirements are met.

[0175] In this embodiment of the application, the first flow rate of each drilling sub in a single-well multi-stage drilling rig is determined, where the first flow rate is the flow rate of drilling fluid in the drilling sub; based on multiple first flow rates, the second flow rate in the casing corresponding to the target drilling sub is determined, where the target drilling sub is the farthest drilling sub; based on the second flow rate, each drilling sub is controlled to drill multiple second branch wells in the first branch wellbore. In the above method, the electronic equipment can dynamically calculate the drilling fluid flow rate of the farthest drilled sub based on the pressure recursion equation and flow resistance model inside and outside the casing. This ensures that all micro-wells obtain a flow rate greater than or equal to the minimum starting flow rate, accurately determines whether the flow rate of all drilled subs meets the drilling requirements, and achieves synchronous drilling. This effectively avoids the problem that some micro-wells (second branch wells) cannot be drilled due to sufficient flow rate at the near end but insufficient flow rate at the far end. It eliminates the need for repeated test drilling to check for insufficient flow rate, improves the preparation efficiency before drilling operations, and ensures the feasibility of synchronous drilling of multiple branch wells. This ensures the smooth implementation of the overall drilling plan. Furthermore, this method can be adapted to scenarios with different well depths and pressure distributions, significantly increasing the reservoir contact area and drainage channels, and improving single-well production. It is especially suitable for low-permeability and fracture-restricted reservoirs, reducing operational problems caused by uneven flow rate distribution.

[0176] In conjunction with any of the above embodiments, the following will be discussed... Figure 8 The process of determining the first flow rate for each drilled section is explained in detail.

[0177] Figure 8 This is a schematic diagram illustrating the process of determining the first flow rate of each drilled section provided in the embodiments of this application. Please refer to... Figure 8 The method may include:

[0178] S801, obtain the first pressure of multiple drilled subs in the casing and the second pressure outside the casing.

[0179] In some embodiments, the first pressure exerted by the drilled sub inside the casing can be expressed as: The second pressure outside the casing can be expressed as .

[0180] The electronic device can acquire the first pressure inside the casing and the second pressure outside the casing of multiple drilled subs in the following manner: For the i-th drilled sub; acquire the first pressure and the i-1 pressure loss corresponding to the (i-1)-th drilled sub, where the i-1 pressure loss is the pressure loss generated when the flow of the (i-1)-th drilled sub flows into the i-th drilled sub; and determine the difference between the first pressure corresponding to the (i-1)-th drilled sub and the i-1 pressure loss as the first pressure corresponding to the i-th drilled sub.

[0181] Obtain the second pressure and the pressure loss corresponding to the (i+1)th drilled section; determine the difference between the second pressure and the pressure loss of the (i+1)th drilled section as the second pressure corresponding to the (i)th drilled section; where i takes the values ​​2, 3, ..., N in sequence, and N is the total number of drilled sections.

[0182] In some embodiments, since the pressure within the casing gradually decreases from the proximal end to the distal end along the direction of the branch wellbore, the electronic equipment can be based on the first pressure corresponding to the (i-1)th drilled sub. And pressure loss, which indicates the pressure loss along the flow direction to the i-th drilled sub. Determine the first pressure corresponding to the i-th drilled section. Then Formula 1 can be expressed as:

[0183]

[0184] In some embodiments, since the pressure outside the casing gradually increases from the proximal end to the distal end along the direction of the branch wellbore, the electronic equipment can be based on the first pressure corresponding to the (i+1)th drilled sub. And pressure loss, which indicates the pressure loss along the flow direction to the i-th drilled sub. Determine the second pressure corresponding to the i-th drilled section. Then formula two can be expressed as:

[0185]

[0186] S802, Obtain the first flow resistance of multiple drilled short sections.

[0187] In some embodiments, the first flow resistance is related to the number of second branch wellbores corresponding to the drilled sub; the more second branch wellbores corresponding to the drilled sub, the smaller the first flow resistance. The first flow resistance of multiple drilled subs can be expressed as follows: .

[0188] S803. Based on multiple first pressures, multiple second pressures, and multiple first flow resistances, determine the first flow rate of multiple drilled subs.

[0189] The electronic device can determine the first flow rate of multiple drilling subs in the following manner, based on multiple first pressures, multiple second pressures, and multiple first flow resistances: for any drilling sub; determine the first pressure difference between the first pressure and the second pressure corresponding to the drilling sub; and determine the ratio of the first pressure difference to the first flow resistance as the first flow rate of the drilling sub.

[0190] In some embodiments, the first pressure difference value of the i-th drilled sub can be expressed as: Then formula three can be expressed as:

[0191]

[0192] In some embodiments, the first flow rate of the i-th drilled section can be expressed as: Then formula four can be expressed as:

[0193]

[0194] In this embodiment of the application, the first pressure of multiple drilling subs is obtained inside the casing, and the second pressure is obtained outside the casing. The first flow resistance of multiple drilling subs is also obtained. Based on the multiple first pressures, multiple second pressures and multiple first flow resistances, the first flow rate of multiple drilling subs is determined. The first pressures and second pressures can be obtained recursively by the pressure and pressure loss of adjacent drilling subs. In the above method, the electronic device can calculate the flow rate of each drilled section by pressure recursion and combining the flow resistance characteristics of each drilled section. By adjusting the flow orifice diameter of the float shoe to meet the minimum starting flow rate of the farthest drilled section, the flow rate of the drilled section can be precisely controlled according to the law of pressure attenuation along the friction. This accurately reflects the actual flow rate status of each section and effectively avoids the problem of flow rate calculation deviation for multiple drilled sections (especially the farthest drilled section). This improves the efficiency and accuracy of flow rate calculation. Furthermore, this method is applicable to drilling scenarios with different numbers and spacings, as well as scenarios with pressure distribution differences caused by different well depths and formations. While improving the accuracy of flow rate calculation, it also improves the reliability and efficiency of multi-branch wellbore drilling.

[0195] In conjunction with any of the above embodiments, the following will be discussed... Figure 9 This paper provides a detailed explanation of the process of multi-stage drilling in a single well.

[0196] Figure 9 This is a schematic diagram illustrating another single-well multi-stage drilling method provided in this application embodiment. Please refer to... Figure 9 The method may include:

[0197] S901. Determine the first flow rate of each drilling sub in a multi-stage drilling rig for a single well.

[0198] The first flow rate is the flow rate of drilling fluid in the drilling sub.

[0199] It should be noted that the execution process of S901 above can be found in S801-S803, and will not be repeated here.

[0200] S902. Obtain the second flow rate in the casing corresponding to the previous drilling sub-section of the target drilling sub-section.

[0201] S903. Determine the sum of the first flow rates corresponding to multiple drilled subs to obtain the third flow rate.

[0202] In some embodiments, if there are N drilled subs, the third flow rate can be expressed as:

[0203]

[0204] In some embodiments, if the flow rate of the floating shoe device is taken into account Based on the law of conservation of flow, the total flow rate in the initial casing is... It can be represented as:

[0205]

[0206] S904. The difference between the second flow rate and the third flow rate is determined as the second flow rate in the casing corresponding to the target drilling sub.

[0207] In some embodiments, the second flow rate within the casing corresponding to the target drilling sub section. It can be represented as:

[0208]

[0209] In some embodiments, the second flow rate within the casing corresponding to the i-th drilled sub-section It can be represented as:

[0210]

[0211] That is, the second flow rate in the casing corresponding to the i-th drilled sub is the difference between the second flow rate in the casing corresponding to the (i-1)-th drilled sub and the third flow rate of the first i drilled subs.

[0212] S905. Based on the second flow rate, control each drilling sub to drill multiple second branch wells in the first branch well.

[0213] In some embodiments, assuming an isotropic homogeneous reservoir, electronic equipment can determine the total reservoir control volume of a single well using a three-dimensional wellbore network. It can be expressed as the following formula five:

[0214]

[0215] in, The reservoir utilization volume for the primary wellbore (Level 1). Let N represent the reservoir utilization volume of the i-th stage 2 first branch well, and let N represent the total number of stage 2 first branch wells. Let M be the reservoir utilization volume of the j-th level 3 second branch well, and M represent the total number of level 3 second branch wells.

[0216] Since the reservoir utilization volume V is related to the length L, Formula 6 can be derived from Formula 5, specifically:

[0217]

[0218] in, The length of the first-stage main wellbore. Let N be the length of the i-th second-stage first-branch wellbore, and N represent the total number of second-stage first-branch wellbores. Let M be the length of the j-th third-stage second-branch well, and M represent the total number of third-stage second-branch wells. The seepage radius is a parameter related to production time, reservoir properties (e.g., permeability, porosity), and fluid properties (e.g., viscosity, compressibility). In this embodiment, it is only used to compare the differences in control volume caused by different well types. Therefore, the seepage radius of each well level is not specified. Simply use the same values ​​as in the initial stage of production.

[0219] Formula 5 can be used to obtain the total reservoir control volume of the single-well multi-level three-dimensional well network in this embodiment of the application. Reservoir control volume with a main wellbore The ratio can be expressed as:

[0220]

[0221] As can be seen from the above formula, under the same drainage radius and within the main wellbore length range, the multi-level three-dimensional wellbore network of a single well in this embodiment can cover a larger volume of reservoir, while forming a "root"-like seepage network, constructing a highly efficient seepage field coupled with linear flow and radial flow, which can significantly improve the single well productivity and recovery rate.

[0222] The single-well multi-stage drilling method provided in this application embodiment can execute the technical solution shown in the above method embodiment. Its implementation principle and beneficial effects are similar, and will not be repeated here.

[0223] Figure 10 This is a schematic diagram of a single-well multi-stage drilling apparatus provided as an embodiment of this application. Please refer to... Figure 10 The single-well multi-stage drilling rig 10 includes: a first determining module 11, a second determining module 12, and a processing module 13, wherein:

[0224] The first determining module 11 is used to determine the first flow rate of each drilling sub in a single-well multi-stage drilling equipment, wherein the first flow rate is the flow rate of drilling fluid in the drilling sub;

[0225] The second determining module 12 is used to determine the second flow rate in the casing corresponding to the target drilling sub, based on multiple first flow rates, wherein the target drilling sub is the farthest drilling sub.

[0226] The processing module 13 is used to control each drilling sub to drill multiple second branch wells in the first branch wellbore according to the second flow rate.

[0227] The single-well multi-stage drilling device provided in this application embodiment can execute the technical solution shown in the above method embodiment. Its implementation principle and beneficial effects are similar, and will not be repeated here.

[0228] In one possible implementation, the first determining module 11 is specifically used for:

[0229] Obtain the first pressure inside the casing and the second pressure outside the casing for multiple drilled subs.

[0230] Obtain the first flow resistance of multiple drilled short sections;

[0231] Based on multiple first pressures, multiple second pressures, and multiple first flow resistances, the first flow rate of multiple drilled subs is determined.

[0232] In one possible implementation, the first determining module 11 is specifically used for:

[0233] Determine the first pressure difference between the first pressure and the second pressure corresponding to the drilling sub;

[0234] The ratio of the first pressure difference to the first flow resistance is determined as the first flow rate when drilling into the short section.

[0235] In one possible implementation, the first determining module 11 is specifically used for:

[0236] For the i-th drilled section;

[0237] Obtain the first pressure and the first pressure loss corresponding to the (i-1)th drilling section. The (i-1)th pressure loss is the pressure loss generated when the flow of the (i-1)th drilling section flows into the ith drilling section.

[0238] The difference between the first pressure corresponding to the (i-1)th drilled section and the (i-1)th pressure loss is determined as the first pressure corresponding to the i-th drilled section.

[0239] Obtain the second pressure and the pressure loss corresponding to the (i+1)th drilled section;

[0240] The difference between the second pressure corresponding to the (i+1)th drilled section and the pressure loss of the (i+1)th drilled section is determined as the second pressure corresponding to the i-th drilled section.

[0241] Where i takes the values ​​2, 3, ..., N in sequence, and N is the total number of short sections drilled in.

[0242] In one possible implementation, the second determining module 12 is specifically used for:

[0243] Obtain the second flow rate in the casing corresponding to the previous drilling sub-segment of the target drilling sub-segment;

[0244] The sum of the first flow rates corresponding to multiple drilled subs is determined to obtain the third flow rate;

[0245] The difference between the second flow rate and the third flow rate is determined as the second flow rate inside the casing corresponding to the target drilled sub.

[0246] The single-well multi-stage drilling device provided in this application embodiment can execute the technical solution shown in the above method embodiment. Its implementation principle and beneficial effects are similar, and will not be repeated here.

[0247] Figure 11 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Figure 11 As shown, the electronic device 20 may include: a transceiver 21, a processor 22, and a memory 23.

[0248] Processor 22 executes computer execution instructions stored in memory, causing processor 22 to perform the scheme in the above embodiments. Processor 22 can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0249] The memory 23 is connected to the processor 22 via the system bus and completes communication between them. The memory 23 is used to store computer program instructions.

[0250] Transceiver 21 can be used to obtain the task to be run and the configuration information of the task to be run.

[0251] The system bus can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. The system bus can be divided into address bus, data bus, control bus, etc. For ease of representation, only one thick line is used in the diagram, but this does not indicate that there is only one bus or one type of bus. Transceivers are used to enable communication between database access devices and other computers (e.g., clients, read-write libraries, and read-only libraries). Memory may include random access memory (RAM) and may also include non-volatile memory.

[0252] The electronic device provided in this application embodiment can be the terminal device described in the above embodiments.

[0253] This application also provides a chip for executing instructions, which is used to execute the technical solution of the single-well multi-stage drilling method in the above embodiments.

[0254] This application also provides a computer-readable storage medium storing computer instructions. When the computer instructions are executed on a computer, the computer performs the technical solution of the single-well multi-stage drilling method described in the above embodiments.

[0255] This application also provides a computer program product, which includes a computer program stored in a computer-readable storage medium. At least one processor can read the computer program from the computer-readable storage medium. When the at least one processor executes the computer program, it can implement the technical solution of the single-well multi-stage drilling method in the above embodiments.

[0256] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices, or modules, and may be electrical, mechanical, or other forms.

[0257] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to implement the solution of this embodiment according to actual needs.

[0258] Furthermore, the functional modules in the various embodiments of this application can be integrated into one processing unit, or each module can exist physically separately, or two or more modules can be integrated into one unit. The unit composed of the above modules can be implemented in hardware or in the form of hardware plus software functional units.

[0259] The integrated modules described above, implemented as software functional modules, can be stored in a computer-readable storage medium. These software functional modules, stored in a storage medium, include several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute some steps of the methods of the various embodiments of this application.

[0260] It should be understood that the aforementioned processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), etc. A general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in this invention can be directly manifested as execution by a hardware processor, or execution by a combination of hardware and software modules within the processor.

[0261] The memory may include high-speed RAM, and may also include non-volatile storage (NVM), such as at least one disk storage device, and may also be a USB flash drive, external hard drive, read-only memory, disk or optical disc, etc.

[0262] The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc. For ease of illustration, the buses shown in the accompanying drawings are not limited to a single bus or a single type of bus.

[0263] The aforementioned storage medium can be implemented by any type of volatile or non-volatile storage 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 storage medium can be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0264] An exemplary storage medium is coupled to a processor, enabling the processor to read information from and write information to the storage medium. Alternatively, the storage medium can be an integral part of the processor. The processor and storage medium can reside in an Application Specific Integrated Circuit (ASIC). Alternatively, the processor and storage medium can exist as discrete components in an electronic control unit or main control device.

[0265] Those skilled in the art will understand that all or part of the steps of the above-described method embodiments can be implemented by hardware related to 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; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0266] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A multi-stage drilling method for a single well, characterized in that, The method includes: Determine the first flow rate of each drilling sub in the single-well multi-stage drilling equipment, where the first flow rate is the flow rate of drilling fluid in the drilling sub; Based on multiple first flow rates, determine the second flow rate inside the casing corresponding to the target drilling sub, wherein the target drilling sub is the farthest drilling sub. Based on the second flow rate, control each drilling sub to drill multiple second branch wells in the first branch well; Determining the first flow rate of each drilled sub in the single-well multi-stage drilling equipment includes: The first pressure inside the casing and the second pressure outside the casing are obtained for the multiple drilled subs. Obtain the first flow resistance of the plurality of drilled short sections; The first flow rate of the plurality of drilled sub-sections is determined based on a plurality of first pressures, a plurality of second pressures, and a plurality of first flow resistances. The process of obtaining the first pressure inside the casing and the second pressure outside the casing of the plurality of drilled subs includes: For the i-th drilled section; Obtain the first pressure and the first pressure loss corresponding to the (i-1)th drilling sub, wherein the (i-1)th pressure loss is the pressure loss generated when the flow of the (i-1)th drilling sub flows into the i-th drilling sub; The difference between the first pressure corresponding to the (i-1)th drilled section and the (i-1)th pressure loss is determined as the first pressure corresponding to the i-th drilled section; Obtain the second pressure and the pressure loss corresponding to the (i+1)th drilled section; The difference between the second pressure corresponding to the (i+1)th drilled section and the (i+1)th pressure loss is determined as the second pressure corresponding to the i-th drilled section. Where i takes the values ​​2, 3, ..., N in sequence, and N is the total number of short sections drilled in.

2. The method according to claim 1, characterized in that, For any single drilled section; Based on multiple first pressures, multiple second pressures, and multiple first flow resistances, the first flow rate of the multiple drilled sub-sections is determined, including: Determine the first pressure difference between the first pressure and the second pressure corresponding to the drilled sub; The ratio of the first pressure difference to the first flow resistance is determined as the first flow rate of the drilled sub.

3. The method according to claim 1, characterized in that, Based on multiple first flow rates, determine the second flow rate within the casing corresponding to the target drilled sub, including: Obtain the second flow rate in the casing corresponding to the previous drilling sub-section of the target drilling sub-section; The sum of the first flow rates corresponding to multiple drilled subs is determined to obtain the third flow rate; The difference between the second flow rate and the third flow rate is determined as the second flow rate in the casing corresponding to the target drilling sub.

4. A single-well multi-stage drilling equipment, characterized in that, The single-well multi-stage drilling method according to any one of claims 1-3 includes a guiding component, multiple drilling subs, multiple casings, multiple fixing components, and a suspension component, wherein: The guide component is connected to one end of the sleeve, and the suspension component is connected to the other end of the sleeve; The plurality of casings are respectively connected to the plurality of drilling subs and the plurality of fixing components; The guiding component is used to drive the single-well multi-stage drilling equipment into the first branch wellbore in the main wellbore; The drilling sub is used to drill a second branch wellbore in the first branch wellbore; The fixing component is used to fix the drilled sub to the casing.

5. The single-well multi-stage drilling equipment according to claim 4, characterized in that, The drilling sub includes multiple drilling components and control devices, wherein: The control device is used to control the drilling component to drill into the second branch wellbore along the drilling track in the first branch wellbore; The number of drilling components in each drilling sub is greater than or equal to 2.

6. The single-well multi-stage drilling equipment according to claim 4, characterized in that, The guiding component includes a reentry tool and a floating shoe device, wherein: The float shoe device is arranged in the direction of the guide component toward the first branch wellbore. One end of the re-entry tool is connected to the float shoe device, and the other end of the re-entry tool is connected to the first casing, which is the farthest casing. The reentry tool is used to rotate and guide the single-well multi-stage drilling equipment into the first branch wellbore; The float shoe device is used to control the flow rate of drilling fluid at the farthest drilling sub, which is connected to the first casing.

7. The single-well multi-stage drilling equipment according to claim 4, characterized in that, The plurality of casings, the plurality of drilling subs, and the plurality of fixing components are interconnected in an alternating manner.

8. A single-well multi-stage drilling device, characterized in that, The method for single-well multi-stage drilling according to any one of claims 1-3 includes: a first determining module, a second determining module, and a processing module, wherein: The first determining module is used to determine the first flow rate of each drilling sub in a single-well multi-stage drilling rig, wherein the first flow rate is the flow rate of drilling fluid in the drilling sub; The second determining module is used to determine the second flow rate in the casing corresponding to the target drilling sub, based on multiple first flow rates, wherein the target drilling sub is the farthest drilling sub. The processing module is used to control each drilling sub to drill multiple second branch wells in the first branch wellbore according to the second flow rate; Determining the first flow rate of each drilled sub in the single-well multi-stage drilling equipment includes: The first pressure inside the casing and the second pressure outside the casing are obtained for the multiple drilled subs. Obtain the first flow resistance of the plurality of drilled short sections; The first flow rate of the plurality of drilled sub-sections is determined based on a plurality of first pressures, a plurality of second pressures, and a plurality of first flow resistances. The process of obtaining the first pressure inside the casing and the second pressure outside the casing of the plurality of drilled subs includes: For the i-th drilled section; Obtain the first pressure and the first pressure loss corresponding to the (i-1)th drilling sub, wherein the (i-1)th pressure loss is the pressure loss generated when the flow of the (i-1)th drilling sub flows into the i-th drilling sub; The difference between the first pressure corresponding to the (i-1)th drilled section and the (i-1)th pressure loss is determined as the first pressure corresponding to the i-th drilled section; Obtain the second pressure and the pressure loss corresponding to the (i+1)th drilled section; The difference between the second pressure corresponding to the (i+1)th drilled section and the (i+1)th pressure loss is determined as the second pressure corresponding to the i-th drilled section. Where i takes the values ​​2, 3, ..., N in sequence, and N is the total number of short sections drilled in.

9. An electronic device, characterized in that, include: A processor, and a memory communicatively connected to the processor; The memory stores computer-executed instructions; The processor executes computer execution instructions stored in the memory to implement the method as described in any one of claims 1 to 3.

10. 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 method as described in any one of claims 1 to 3.

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