Method, device and equipment for analyzing pressure drop of serpentine well

Abstract

The invention relates to the technical field of oil and gas field development, and provides a method, device and equipment for analyzing the pressure drop of a serpentine well. The method comprises the steps that micro-arc section extraction and basic parameter setting are conducted on the serpentine well; according to the set basic parameters, micro-arc section flow characteristic analysis is conducted, and in combination with a fluid continuity equation and a momentum conservation equation, a serpentine well horizontal section single-phase pressure drop gradient prediction model is established; predicting pressure gradient data in the serpentine well by using the serpentine well horizontal section single-phase pressure drop gradient prediction model; and the serpentine well is set to adopt fixed bottom hole flowing pressure production, and the pressure drop of the horizontal section of the serpentine well is calculated by adopting a pressure drop superposition method according to the pressure gradient data in the serpentine well. According to the method, the influence of the geometrical morphology change of the shaft on fluid flow is effectively described, especially the continuous change of the gravity component along with the hole drift angle, and the inherent defect that a traditional model simplifies the shaft into horizontal flow is overcome.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application generally relate to the technical field of oil and gas field development, and in particular, to a method, device and equipment for analyzing pressure drop of a meandering well. BACKGROUND

[0002] In the research of horizontal well production technology, the traditional analysis model is usually based on the idealized assumption of horizontal wellbore, simplifies the flow in the well to an infinite conductivity state, and ignores the influence of the pressure drop of the wellbore itself. Although the wellbore pressure drop effect has been gradually recognized since the early research, subsequent scholars have also proposed various models to predict the pressure drop of conventional horizontal wells. However, these models have a fundamental limitation: they do not fully consider the longitudinal undulation phenomenon of the well trajectory generated in the actual drilling process and the complex flow effects caused thereby.

[0003] As a kind of complex structure well with obvious longitudinal undulation characteristics, the wellbore of the meandering well is not in an ideal horizontal state, but has continuous or local inclination and undulation. This spatial geometric change directly leads to a substantial change in the fluid flow behavior in the wellbore: on the one hand, the gravity component changes constantly with the inclination angle of the well section, significantly affecting the potential energy distribution and flow stability of the fluid; on the other hand, the undulating structure intensifies the mixing intensity between the radial inflow fluid and the main flow, causing additional mixing pressure drop that is not covered by the traditional model. In addition, the undulating change of the well shape also makes the classic flow assumption based on uniform inflow and stable flow state lose its applicability.

[0004] Therefore, if the traditional horizontal well pressure drop model is still used to analyze the meandering well, not only the unique flow characteristics of the meandering well cannot be accurately captured, but also the pressure drop prediction error will increase, which will directly affect the development effect evaluation and production system optimization. At present, the meandering well is increasingly applied in many oil and gas regions (such as Guizhou region) at home and abroad, but the pressure drop analysis means suitable for its structural characteristics is still insufficient. SUMMARY

[0005] To solve the above problems, the present application extracts a micro-arc section at the toe end of the horizontal section of the meandering well, analyzes the flow characteristics, establishes a pressure gradient model combining the fluid continuity equation and the momentum conservation equation, calculates the pressure drop of the well section by using the pressure drop superposition method, and finally sets the meandering well to produce with a constant bottom hole flowing pressure. According to the obtained pressure gradient data in the meandering well, the pressure drop of the horizontal section of the meandering well is calculated by using the pressure drop superposition method. This method realizes the accurate physical description of the undulating well section of the meandering well, effectively depicts the influence of the change of the wellbore geometric shape on the fluid flow through the local linearization approximation of the micro-arc section, and overcomes the inherent defect of the traditional model that simplifies the wellbore to horizontal flow.

[0006] According to the embodiments of the present application, a method, device and equipment for analyzing pressure drop of a meandering well are provided.

[0007] In a first aspect of the invention, a method for pressure drop analysis of meandering wells is provided. The method includes: Step S01: Extract micro-arc segments and set basic parameters for the meandering well; Step S02: Analyze the flow characteristics of the micro-arc segment based on the set basic parameters, and establish a single-phase pressure drop gradient prediction model for the horizontal section of the meandering well by combining the fluid continuity equation and the momentum conservation equation. Step S03: Use the single-phase pressure drop gradient prediction model for the horizontal section of the meandering well to predict the pressure gradient data within the meandering well; Step S04: Set the serpentine well to use constant bottom pressure for production, and calculate the pressure drop of the horizontal section of the serpentine well using the pressure drop superposition method based on the pressure gradient data inside the serpentine well.

[0008] Furthermore, the micro-arc segment mentioned in step S01 includes a small arc segment of fluid straight flow obtained at the toe of the horizontal section of the meandering well.

[0009] Furthermore, the basic parameters mentioned in step S01 include: the horizontal arc length and cross-sectional radius of the meandering well.

[0010] Furthermore, the step of establishing the single-phase flow pressure gradient model of the meandering well described in step S02 is as follows: Step S021: Take a micro-arc segment at the toe of the horizontal section of the meandering well; Step S022: Perform data analysis on the micro-arc segment to obtain flow characteristics, including the component of gravity in the micro-arc segment. Micro-arc inlet pressure Micro-arc segment outflow end pressure Liquid phase tube wall friction resistance Liquid flow rate at the upstream section of the micro-arc segment Liquid flow rate at the downstream section of the micro-arc segment ; Step S023: Establish the continuity equation and kinetic energy equation ,in, This refers to the volume of liquid flowing from the reservoir into the micro-arc segment. This refers to the local resistance experienced by the fluid within the micro-element segment. The frictional resistance between the liquid phase and the pipe wall. This represents the perimeter length of the contact area between the liquid phase and the tube wall. This refers to the mass of the liquid phase per unit length within the spiral wellbore. Indicates the flow rate of the fluid; Step S024: Based on the continuity equation and the dynamic conservation equation, and combined with the local resistance loss generated when the fluid passes through the curved section of the meandering well, the single-phase flow pressure gradient model of the meandering well is obtained.

[0011] Furthermore, the single-phase flow pressure gradient model for the meandering well is as follows: , in, This indicates the number of bends the current segment has passed through. This indicates the pressure loss caused by local resistance. The angle between the axis of the meandering well shaft and the horizontal direction. It is the cross-sectional area of ​​the well shaft. It is the pressure gradient value.

[0012] Furthermore, the specific steps of step S03 are as follows: Step S031: Divide the horizontal section of the meandering well into... There are several small segments, each with a length of [length missing]. The angle of inclination is Let the pressure at the upstream inlet of the horizontal section be... ; Step S032: For any horizontal section of a meandering well Calculate its average pressure ,in for Pressure at the upstream inlet of the section, for The initial estimated pressure at the downstream outlet end of the segment, and based on the average pressure. Determine the production pressure difference of this section and calculate the inflow of this section using formula (2); Step S033: Calculate the single-phase pressure drop gradient prediction model for the horizontal section of the meandering well. pressure drop of the segment ; Step S034: Comparison and If the given error range is met, proceed to the next segment. Otherwise, with As a new Recalculate until the requirements are met.

[0013] Furthermore, the specific steps of step S04 are as follows: Step S041: Calculate the pressure drop of each section along the horizontal section of the meandering well, until the last section. .

[0014] Step S042: Compare the specified bottom hole flowing pressure with the calculated pressure. If the pressure at the outlet of a section meets the error range, the total pressure drop is the sum of the pressure drops of each section; otherwise, reset. Repeat the above steps until the required calculation accuracy is met.

[0015] In a second aspect of the invention, an apparatus for analyzing pressure drop in meandering wells is provided. The apparatus includes: Basic parameter setting module: used to set basic parameters for meandering wells; Micro-arc segment extraction module: used to extract micro-arc segments; Micro-arc segment analysis module: used for systematic analysis of micro-arc segment flow characteristics based on basic parameter data. Micro-arc segments include small arc segments of fluid straight flow taken at the toe of the horizontal section of a meandering well. Pressure gradient calculation module: Connected to the micro-arc segment analysis module, used to calculate the pressure gradient data in the well based on the flow characteristics of the micro-arc segment; Horizontal section pressure drop calculation module: Connected to the pressure gradient calculation module, it is used to calculate the overall pressure drop of the horizontal section of the meandering well based on the pressure gradient data using the pressure drop superposition method under the set bottom hole flowing pressure production conditions.

[0016] In a third aspect of the invention, an electronic device is provided. The electronic device includes a memory and a processor, the memory storing a computer program, the processor executing the program to implement the method according to a first aspect of the invention.

[0017] In a fourth aspect of the invention, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the method according to a first aspect of the invention.

[0018] This invention extracts a micro-arc segment at the toe of the horizontal section of a meandering well, analyzes its flow characteristics, and establishes a pressure gradient model by combining the fluid continuity equation and the momentum conservation equation. The pressure drop in the well section is calculated using the pressure drop superposition method. Finally, the meandering well is set to produce under constant bottom-hole flowing pressure. Based on the obtained pressure gradient data within the meandering well, the pressure drop in the horizontal section of the meandering well is calculated using the pressure drop superposition method. This method achieves an accurate physical description of the undulating well section of the meandering well. Through the local linearization approximation of the micro-arc segment, it effectively characterizes the influence of wellbore geometry changes on fluid flow, especially the continuous change of the gravity component with the well inclination angle, overcoming the inherent defect of traditional models that simplify the wellbore as horizontal flow.

[0019] It should be understood that the description in the Summary of the Invention is not intended to limit the key or essential features of the embodiments of the present invention, nor is it intended to restrict the scope of the invention. Other features of the invention will become readily apparent from the following description.

[0020] Beneficial effects: 1. By extracting micro-arc segments at the toe of the horizontal section of a meandering well, flow characteristics are analyzed, and a pressure gradient model is established by combining the fluid continuity equation and the momentum conservation equation. The pressure drop of the well section is calculated using the pressure drop superposition method. Finally, the meandering well is set to produce under constant bottom hole pressure. Based on the pressure gradient data obtained in the meandering well, the pressure drop of the horizontal section of the meandering well is calculated using the pressure drop superposition method. This method achieves an accurate physical description of the undulating section of the meandering well. Through the local linearization approximation of the micro-arc segments, the influence of the wellbore geometry changes on fluid flow is effectively characterized, especially the continuous change of the gravity component with the well inclination angle, overcoming the inherent defect of the traditional model that simplifies the wellbore to horizontal flow. 2. By coupling the fluid continuity equation and the momentum conservation equation, and simultaneously considering the frictional pressure drop and the mixing pressure drop generated by the radial inflow fluid mixing with the mainstream, the complex flow phenomena in the meandering well are fully captured, effectively reducing the calculation errors caused by neglecting the mixing effect and fluctuation effect, and providing a more reliable data basis for production prediction and production optimization. 3. By adopting micro-arc segment analysis and the principle of superimposing pressure drop of several unit segments, this method is easy to program and can be efficiently integrated into existing production analysis software. This method can provide key theoretical basis for the trajectory optimization design and production system adjustment of meander wells, improve the controlled reserves and final recovery rate of single wells, and has important promotional value for the efficient development of meander wells in mountainous and hilly areas of my country. Attached Figure Description

[0021] The above and other features, advantages, and aspects of the various embodiments of the present invention will become more apparent from the accompanying drawings and the following detailed description. Wherein: Figure 1 A flowchart of a method for analyzing pressure drop in serpentine wells according to an embodiment of the present invention is shown; Figure 2 A schematic diagram of a meandering well according to an embodiment of the present invention is shown; Figure 3 A schematic diagram illustrating the analysis of single-phase flow characteristics of micro-element according to an embodiment of the present invention is shown; Figure 4 A diagram of an apparatus for analyzing pressure drop in a meandering well according to an embodiment of the present invention is shown; Figure 5 A schematic diagram of an apparatus for analyzing pressure drop in a meandering well according to an embodiment of the present invention is shown. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] According to embodiments of the present invention, a method, apparatus, and equipment for pressure drop analysis of meandering wells are proposed. By extracting micro-arc segments at the toe of the horizontal section of the meandering well, flow characteristic analysis is performed, and a pressure gradient model is established by combining the fluid continuity equation and the momentum conservation equation. The pressure drop of the well section is calculated using the pressure drop superposition method. Finally, the meandering well is set to produce under constant bottom-hole flowing pressure. Based on the obtained pressure gradient data within the meandering well, the pressure drop of the horizontal section of the meandering well is calculated using the pressure drop superposition method. This method achieves an accurate physical description of the undulating well section of the meandering well. Through the local linearization approximation of the micro-arc segments, the influence of wellbore geometry changes on fluid flow is effectively characterized, especially the continuous change of the gravity component with the well inclination angle, overcoming the inherent defect of traditional models that simplify the wellbore as horizontal flow.

[0024] The principles and spirit of the present invention will be explained in detail below with reference to several representative embodiments.

[0025] Figure 1 This is a schematic flowchart of a method for pressure drop analysis in a meandering well according to an embodiment of the present invention. The method includes: Step S01: Extract micro-arc segments and set basic parameters for the meandering well; Step S02: Analyze the flow characteristics of the micro-arc segment based on the set basic parameters, and establish a single-phase pressure drop gradient prediction model for the horizontal section of the meandering well by combining the fluid continuity equation and the momentum conservation equation. Step S03: Use the single-phase pressure drop gradient prediction model for the horizontal section of the meandering well to predict the pressure gradient data within the meandering well; Step S04: Set the serpentine well to use constant bottom pressure for production, and calculate the pressure drop of the horizontal section of the serpentine well using the pressure drop superposition method based on the pressure gradient data inside the serpentine well.

[0026] It should be noted that although the operation of the method of the present invention has been described in a specific order in the above embodiments and figures, this does not require or imply that the operations must be performed in that specific order, or that all the operations shown must be performed to achieve the desired result. Additionally or alternatively, certain steps may be omitted, multiple steps may be combined into one step, and / or one step may be broken down into multiple steps.

[0027] To provide a clearer explanation of the above-mentioned method for analyzing pressure drop in meandering wells, a specific embodiment will be used for illustration below. However, it is worth noting that this embodiment is only for better illustrating the present invention and does not constitute an improper limitation of the present invention.

[0028] The following example will further illustrate the method of pressure drop analysis in serpentine wells in more detail.

[0029] This embodiment uses, as follows: Figure 2 The well conditions and basic parameters of the meandering well shown are shown in Table 1 (based on actual meandering well data from a shale gas field in Guizhou).

[0030] Table 1

[0031] Experimental equipment and tools

[0032] 1. Data acquisition equipment: bottom hole pressure sensor, flow meter, well inclination angle measuring instrument; 2. Computing equipment: An industrial computer equipped with MATLAB 2022b; 3. Validation tools: traditional horizontal well pressure drop model and actual field production monitoring data.

[0033] Step S01: Extract micro-arc segments and set basic parameters for the meandering well.

[0034] Micro-arc segments include small arc segments of fluid flow obtained at the toe of the horizontal section of a meandering well.

[0035] The basic parameters include: the horizontal arc length and cross-sectional radius of the meandering well.

[0036] In this embodiment, three continuous micro-arc segments were extracted from the toe of the horizontal section of the meandering well. Each micro-arc segment was 0.5m long and the measured inclination angles were -2.1°, -2.3°, and -2.0°, respectively.

[0037] A horizontal section of the wellbore is designed for single-phase liquid flow. No fluid flows into the toe of the horizontal section of the wellbore, and the fluid does not perform any mechanical work as it flows through the wellbore.

[0038] Step S02: Analyze the flow characteristics of the micro-arc segment based on the set basic parameters, and establish a single-phase flow pressure gradient model for the meandering well by combining the fluid continuity equation and the momentum conservation equation.

[0039] The steps for establishing a single-phase flow pressure gradient model for a meandering well are as follows: Step S021: Take a micro-arc segment at the toe of the horizontal section of the meandering well. The inclination angle of the micro-arc segment The range of values ​​is .

[0040] Step S022: Perform data analysis on the micro-arc segment to obtain flow characteristics, including the component of gravity in the micro-arc segment. Micro-arc inlet pressure Micro-arc segment outflow end pressure Liquid phase tube wall friction resistance Liquid flow rate at the upstream section of the micro-arc segment Liquid flow rate at the downstream section of the micro-arc segment ; Step S023: Establish the continuity equation, such as Figure 3 As shown, the continuity equation in this embodiment includes: (1) In the formula, The volume of liquid flowing from the reservoir into the micro-arc segment; (2) In the formula, The static pressure of the reservoir outside the wellbore; This refers to the bottom pressure at the upstream inlet (heel end) of the meandering well; Oil production index.

[0041] Step S024: Establish the kinetic energy equation. Based on the fact that the external force acting on the micro-arc segment is equal to the change in fluid momentum, the dynamic conservation equation is: (3) In the formula, This represents the local resistance experienced by the fluid within the micro-element segment.

[0042] Step S025: Based on the above continuity equation and dynamic conservation equation, the radial inflow and mainstream fluid mixing is accompanied by energy loss, i.e., there is also a mixing pressure drop. This leads to the basic pressure gradient model: (4) The mixed pressure drop in the above formula is derived from an empirical correlation through experiments: (5) (6) Combining formulas (5) and (6), we get: (7) Subsequently, ignoring the mixing pressure drop and acceleration pressure drop, equation (7) can be simplified to: (8) in, The frictional shear stress, which is the frictional resistance between the liquid phase and the pipe wall, can be determined by the Darcy-Weisbach formula, as follows: (9) in, The coefficient of friction in the liquid phase is calculated as follows: (10) Introducing the calculation formula for typical local resistance loss (also known as local pressure loss or additional loss) in fluid mechanics: (11) In the formula, This represents the pressure loss caused by local resistance, expressed in meters. It is the local resistance coefficient, a dimensionless quantity that depends on the shape of the pipe components and the flow state. This indicates the velocity of the fluid, measured in meters per second. It is the acceleration due to gravity, measured in meters per second squared. When considering the local resistance loss generated when fluid flows through the curved section of the wellbore (i.e., only considering the inflection point of the curve), the formula is: (12) It can be transformed into formula (13). (13) This is the final pressure gradient model, where, This represents the frictional resistance between the liquid phase and the pipe wall. This refers to the volume of fluid flowing from the reservoir into a unit length of meandering well; The angle between the axis of the meandering well shaft and the horizontal direction; The mass of the liquid phase per unit length of the meandering wellbore; This is the perimeter length of the contact area between the liquid phase and the tube wall; Indicates the number of bends traversed by the current segment; This represents the pressure loss caused by local resistance, expressed in meters. The density of the liquid phase; This indicates the velocity of the fluid, measured in meters per second. It is the acceleration due to gravity; It is the cross-sectional area of ​​the well shaft; It is the pressure gradient value.

[0043] In this embodiment, the pressure at the inlet of the micro-arc segment was measured to be 29.8 MPa, the pressure at the outlet of the micro-arc segment was 29.5 MPa, and the liquid flow rate at the upstream section of the micro-arc segment was 0.012 MPa. The fluid flow rate at the downstream section of the micro-arc segment is 0.0123. .

[0044] Step S03: Use the single-phase pressure drop gradient prediction model of the horizontal section of the meandering well to predict the pressure gradient data in the meandering well.

[0045] The specific steps are as follows: Step S031: Divide the horizontal section of the meandering well into... There are several small segments, each with a length of [length missing]. The angle of inclination is Let the pressure at the upstream inlet of the horizontal section be... .

[0046] Step S032: For any horizontal section of a meandering well Calculate its average pressure ,in for Pressure at the upstream inlet of the section, for The initial estimated pressure at the downstream outlet end of the segment, and based on the average pressure. Determine the production pressure difference of this section and calculate the inflow of this section using formula (2).

[0047] Step S033: Calculate the single-phase pressure drop gradient prediction model for the horizontal section of the meandering well. pressure drop of the segment .

[0048] Step S034: Comparison and If the given error range is met, proceed to the next segment. Otherwise, with As a new Recalculate until the requirements are met.

[0049] In this embodiment, the 820m long horizontal section is divided into 20 segments, each 41m long. The inclination angle of each segment is measured, and the pressure at the upstream inlet of the horizontal section is set to 32.5MPa.

[0050] Iterative calculation (taking the first segment as an example): The initial estimated downstream pressure is 31.0 MPa, and the calculated average pressure is 31.75 MPa. For any horizontal segment of the meandering well... The calculated production pressure differential is 0.75 MPa, and the inflow rate is calculated to be 2.1 × 10⁻⁶ MPa. m³ / s. Substituting the relevant parameters into the pressure gradient model, the pressure drop in the first segment was calculated to be 0.82 MPa. The downstream calculated pressure was then the upstream inlet pressure minus this pressure drop, which was 31.68 MPa. The absolute value of the difference between the calculated downstream pressure and the initially estimated downstream pressure was 0.68 MPa, corresponding to an error of 2.2%, which exceeded the allowable error range of 1.0%, requiring iteration. The initial estimated downstream pressure was reset to 31.68 MPa, and the above calculation process was repeated. After three iterations, the error decreased to 0.8%, meeting the allowable error requirement. The final determined pressure drop in the first segment was 0.85 MPa, and the downstream pressure was 31.65 MPa. Following the calculation process for the first segment, the iterative calculations for all 20 segments were completed sequentially to obtain the pressure gradient data for each segment.

[0051] Step S04: Set the serpentine well to use constant bottom pressure for production, and calculate the pressure drop of the horizontal section of the serpentine well using the pressure drop superposition method based on the pressure gradient data inside the serpentine well.

[0052] The specific steps are as follows: Step S041: Calculate the pressure drop of each section along the horizontal section of the meandering well, until the last section. .

[0053] Step S042: Compare the specified bottom hole flowing pressure with the calculated pressure. If the pressure at the outlet of a section meets the error range, then the total pressure drop is the sum of the pressure drops of each section. Otherwise, reset. Repeat the above steps until the required calculation accuracy is met.

[0054] In this embodiment, the pressure drops of the 20 calculated segments are summed to obtain an initial total pressure drop of 13.8 MPa. The final outlet pressure is the upstream inlet pressure minus the initial total pressure drop, which is 18.7 MPa. The set bottomhole flowing pressure is 18.0 MPa. The absolute value of the difference between the calculated final outlet pressure and the set bottomhole flowing pressure is 0.7 MPa, with an error of 3.9%, which is greater than the allowable error range of 1.0%. The upstream inlet pressure needs to be adjusted for iteration. The upstream inlet pressure is reset to 32.2 MPa, and the calculation process of steps S03 to S04 is repeated. After two rounds of iteration, the final outlet pressure is 18.05 MPa, with an error of 0.28%, which is less than the allowable error range of 1.0%, meeting the calculation accuracy requirements. The final total pressure drop is the reset upstream inlet pressure minus the final outlet pressure, which is calculated to be 14.15 MPa.

[0055] Specifically, the calculation data for some unit segments are shown in Table 2: Table 2

[0056] The total pressure drop calculated by the method of this invention is 14.15 MPa, while the actual measured total pressure drop in the field is 13.99 MPa, with an error of only 1.07%. In contrast, the total pressure drop calculated by the traditional model is 11.82 MPa, with an error of 16.3% compared to the actual measured value. The core difference lies in the fact that the method of this invention fully considers the influence of gravity in the meandering well, the pressure drop caused by fluid mixing, and the local resistance of the bend, while the traditional model assumes that the wellbore is in an ideal horizontal state and ignores the gravity component and the local resistance of the bend, resulting in a larger error.

[0057] The total pressure drop calculated by the method of this invention has an error of only 1.07% compared with the field measurement, far lower than the 16.3% error of the traditional model. This fully verifies the good adaptability of the model to the undulating structure of the meandering well and its ability to accurately predict the pressure drop in the horizontal section of the meandering well. The number of iterations for each unit segment is between 2 and 4, and the overall calculation time is 8.3 seconds, which can meet the needs of real-time engineering analysis and has high efficiency. Through local linearization of micro-arc segments and pressure drop superposition method, the method of this invention can accurately capture the continuous change of gravity component in the meandering well with the dip angle. For example, when the dip angle of the 5th segment is -2.8°, the contribution of gravity component to the pressure drop reaches 23%. At the same time, it can also accurately calculate the local resistance of the bend segment (average proportion of 12%), effectively solving the inherent defect of the traditional model that simplifies the wellbore as horizontal flow.

[0058] This embodiment uses field monitoring data from actual oil and gas field meander wells for verification. All basic parameters are derived from the well completion report and production data. The experimental results are repeatable, with errors in multiple iterations ≤1.2%. The experimental results demonstrate that the method of this invention can accurately predict the pressure drop in the horizontal section of meander wells, providing reliable data support for production system optimization and is suitable for the efficient development of meander wells in mountainous and hilly areas.

[0059] Based on the same inventive concept, this invention also proposes a device for analyzing pressure drop in meandering wells. For example... Figure 4 As shown, the device includes: a basic parameter setting module 1, a micro-arc segment extraction module 2, a micro-arc segment analysis module 3, a pressure gradient calculation module 4, and a horizontal segment pressure drop calculation module 5.

[0060] The system comprises the following modules: Basic Parameter Setting Module 1 for setting basic parameters of the meandering well; Micro-Arc Segment Extraction Module 2 for extracting micro-arc segments; and Micro-Arc Segment Analysis Module 3 for performing a systematic analysis of the flow characteristics of micro-arc segments based on the basic parameter data. Micro-arc segments include small arc segments of fluid straight-line flow taken at the toe of the horizontal section of the meandering well. Pressure Gradient Calculation Module 4 is connected to Micro-Arc Segment Analysis Module 3 and is used to calculate the pressure gradient data within the well based on the flow characteristics of the micro-arc segments. Horizontal Section Pressure Drop Calculation Module 5 is connected to Pressure Gradient Calculation Module 4 and is used to calculate the overall pressure drop of the horizontal section of the meandering well using the pressure drop superposition method based on the pressure gradient data under set bottom-hole flowing pressure production conditions.

[0061] It should be further explained that the pressure gradient calculation module 4 in this embodiment includes a fluid continuity equation unit 41 and a momentum conservation equation unit 42. Specifically, the fluid continuity equation unit 41 is connected to the micro-arc segment analysis module 3 and is used to describe the reservoir liquid phase flow based on the flow characteristics of the micro-arc segment, and to construct a single-phase pressure drop prediction model for the horizontal section of the meandering well. The momentum conservation equation unit 42 works in conjunction with the fluid continuity equation unit 41 to represent the relationship between the external force on the micro-arc segment and the change in fluid momentum. The external force includes the mixing pressure drop caused by the energy loss due to the mixing of radial inflow and mainstream fluid. The pressure gradient model is derived by combining the fluid continuity equation module to obtain the pressure gradient data in the well.

[0062] The horizontal section pressure drop calculation module 5 includes a well section division unit 51 for dividing the horizontal section of the meandering well into several unit segments, a pressure initialization unit 52 connected to the well section division unit 51 for setting the initial estimated pressure at the upstream inlet end of the horizontal section and the downstream outlet end of the first unit segment, an iterative calculation control unit 53, a pressure drop calculation unit 54, and an error comparison and convergence judgment unit 55. Specifically, the iterative calculation control unit 53 is connected to the pressure initialization unit 52 and is used to control the pressure drop calculation along the horizontal section of the meandering well according to the initial pressure setting. Each unit segment undergoes iterative voltage drop calculation; the voltage drop calculation unit 54 is data-connected to the iterative calculation control unit 53 and is used to execute the voltage drop calculation for each unit segment; the error comparison and convergence judgment unit 55 is connected to the voltage drop calculation unit 54 and is used to perform iterative voltage drop calculation for each unit segment. The calculated pressure at the outlet of each unit segment is compared with the set bottom hole pressure, and the convergence condition is determined based on the comparison result to trigger the final total pressure drop calculation.

[0063] Specifically, the pressure drop calculation unit 54 includes an average pressure calculation unit 541, a production pressure difference and inflow calculation unit 542, a unit pressure drop calculation unit 543, a flow pressure error judgment unit 544, and an iterative control unit 545. The average pressure calculation unit 541 calculates the average pressure of the current unit segment based on the upstream pressure and the initially estimated downstream pressure. The production pressure difference and inflow calculation unit 542 is connected to the average pressure calculation unit 541 and is used to calculate the production pressure difference of the current unit segment based on the average pressure, and accordingly calculate the inflow of the unit segment. The unit pressure drop calculation unit 543 is connected to the production pressure difference and inflow calculation unit 542. The system is connected to the unit pressure drop calculation unit 543, which is used to calculate the pressure drop of the current unit segment based on the inflow rate using the serpentine well pressure drop calculation model. The flow pressure error judgment unit 544 is connected to the unit pressure drop calculation unit 543 and is used to compare the calculated downstream flow pressure of the current unit segment with the set initial estimated pressure to determine whether the difference between the two is within the preset error range. The iterative control unit 545 is connected to the flow pressure error judgment unit 544. If the flow pressure error of the current unit segment meets the preset range, the control device continues to process the next unit segment. If it does not meet the preset range, the calculated downstream flow pressure is used as the new estimated pressure to trigger the recalculation of the unit segment until the error requirement is met.

[0064] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the described module can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0065] like Figure 5 As shown, the device includes a central processing unit (CPU), which can perform various appropriate actions and processes based on computer program instructions stored in read-only memory (ROM) or loaded from storage units into random access memory (RAM). The RAM can also store various programs and data required for device operation. The CPU, ROM, and RAM are interconnected via a bus. Input / output (I / O) interfaces are also connected to the bus.

[0066] Multiple components in the device are connected to the I / O interface, including: input units such as keyboards and mice; output units such as various types of displays and speakers; storage units such as disks and optical discs; and communication units such as network interface cards (NICs), modems, and wireless transceivers. The communication unit allows the device to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0067] The processing unit executes the various methods and processes described above, such as method steps S01 to S04. For example, in some embodiments, method steps S01 to S04 may be implemented as a computer software program tangibly contained in a machine-readable medium, such as a storage unit. In some embodiments, part or all of the computer program may be loaded and / or installed on the device via ROM and / or a communication unit. When the computer program is loaded into RAM and executed by the CPU, one or more steps of method steps S01 to S04 described above may be performed. Alternatively, in other embodiments, the CPU may be configured to execute method steps S01 to S04 by any other suitable means (e.g., by means of firmware).

[0068] The functions described above in this document can be performed at least in part by one or more hardware logic components. For example, exemplary types of hardware logic components that can be used, without limitation, include: field programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload programmable logic devices (CPLDs), and so on.

[0069] The program code used to implement the methods of the present invention can be written in any combination of one or more programming languages. This program code can be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing device, such that when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code can be executed entirely on the machine, partially on the machine, as a standalone software package partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0070] In the context of this invention, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. Machine-readable media can include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0071] Furthermore, although the operations are described in a specific order, this should be understood as requiring that such operations be performed in the specific order shown or in sequential order, or requiring that all illustrated operations be performed to achieve the desired result. In certain environments, multitasking and parallel processing may be advantageous. Similarly, although several specific implementation details are included in the above discussion, these should not be construed as limiting the scope of the invention. Certain features described in the context of individual embodiments may also be implemented in combination in a single implementation. Conversely, various features described in the context of a single implementation may also be implemented individually or in any suitable sub-combination in multiple implementations.

[0072] Although the subject matter has been described using language specific to structural features and / or methodological logic, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are merely illustrative examples of implementing the claims.

Claims

1. A method for pressure drop analysis in meandering wells, characterized in that, The method includes: Step S01: Extract micro-arc segments and set basic parameters for the meandering well; Step S02: Analyze the flow characteristics of the micro-arc segment based on the set basic parameters, and establish a single-phase pressure drop gradient prediction model for the horizontal section of the meandering well by combining the fluid continuity equation and the momentum conservation equation. Step S03: Use the single-phase pressure drop gradient prediction model for the horizontal section of the meandering well to predict the pressure gradient data within the meandering well; Step S04: Set the serpentine well to use constant bottom pressure for production, and calculate the pressure drop of the horizontal section of the serpentine well using the pressure drop superposition method based on the pressure gradient data inside the serpentine well.

2. The method for pressure drop analysis of a meandering well according to claim 1, characterized in that, The micro-arc segment mentioned in step S01 includes a small arc segment of fluid straight flow obtained at the toe of the horizontal section of the meandering well.

3. The method for pressure drop analysis of a meandering well according to claim 1, characterized in that, The basic parameters mentioned in step S01 include: the horizontal arc length and cross-sectional radius of the meandering well.

4. The method for pressure drop analysis of a meandering well according to claim 1, characterized in that, The steps for establishing the single-phase flow pressure gradient model of the meandering well described in step S02 are as follows: Step S021: Take a micro-arc segment at the toe of the horizontal section of the meandering well; Step S022: Perform data analysis on the micro-arc segment to obtain flow characteristics, including the component of gravity in the micro-arc segment. Micro-arc inlet pressure Micro-arc segment outflow pressure Liquid phase tube wall friction resistance Liquid flow rate at the upstream section of the micro-arc segment Liquid flow rate at the downstream section of the micro-arc segment ; Step S023: Establish the continuity equation and kinetic energy equation ,in, This refers to the volume of liquid flowing from the reservoir into the micro-arc segment. This refers to the local resistance experienced by the fluid within the micro-element segment. The frictional resistance between the liquid phase and the pipe wall. This is the perimeter length of the contact area between the liquid phase and the tube wall. This refers to the mass of the liquid phase per unit length within the spiral wellbore. Indicates the flow rate of the fluid; Step S024: Based on the continuity equation and the dynamic conservation equation, and combined with the local resistance loss generated when the fluid passes through the curved section of the meandering well, the single-phase flow pressure gradient model of the meandering well is obtained.

5. The method for pressure drop analysis of a meandering well according to claim 4, characterized in that, The single-phase flow pressure gradient model for the meandering well is as follows: ， in, This indicates the number of bends the current segment has passed through. This indicates the pressure loss caused by local resistance. The angle between the axis of the meandering well shaft and the horizontal direction. It is the cross-sectional area of ​​the well shaft. It is the pressure gradient value.

6. The method for pressure drop analysis of a meandering well according to claim 1, characterized in that, The specific steps of step S03 are as follows: Step S031: Divide the horizontal section of the meandering well into... There are several small segments, each with a length of [length missing]. The angle of inclination is Let the pressure at the upstream inlet of the horizontal section be... ; Step S032: For any horizontal section of a meandering well Calculate its average pressure ,in for Pressure at the upstream inlet of the section, for The initial estimated pressure at the downstream outlet end of the segment, and based on the average pressure. Determine the production pressure difference of this section and calculate the inflow of this section using formula (2); Step S033: Using the single-phase pressure drop gradient prediction model of the horizontal section of the meandering well, calculate... pressure drop of the segment ; Step S034: Comparison and If the given error range is met, proceed to the next segment. Otherwise, with As a new Recalculate until the requirements are met.

7. The method for pressure drop analysis of a meandering well according to claim 6, characterized in that, The specific steps of step S04 are as follows: Step S041: Calculate the pressure drop of each section along the horizontal section of the meandering well, until the last section. . Step S042: Compare the specified bottom hole flowing pressure with the calculated pressure. If the pressure at the outlet of a section meets the error range, the total pressure drop is the sum of the pressure drops of each section; otherwise, reset. Repeat the above steps until the required calculation accuracy is met.

8. An apparatus for analyzing pressure drop in meandering wells, characterized in that, The device implements the method as described in any one of claims 1 to 7, comprising: Basic parameter setting module (1): used to set basic parameters for meandering wells; Micro-arc segment extraction module (2): used to extract micro-arc segments; Micro-arc segment analysis module (3): used for systematic analysis of micro-arc segment flow characteristics based on basic parameter data. Micro-arc segment includes a small arc segment of fluid straight flow taken at the toe of the horizontal section of the meandering well. Pressure gradient calculation module (4): connected to the micro-arc segment analysis module (5) for calculating the pressure gradient data in the well based on the flow characteristics of the micro-arc segment; Horizontal section pressure drop calculation module (5): It is connected to the pressure gradient calculation module (4) and is used to calculate the overall pressure drop of the horizontal section of the meandering well based on the pressure gradient data using the pressure drop superposition method under the set bottom flow pressure production conditions.

9. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the program, it implements the method as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the method as described in any one of claims 1 to 7.

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