Method and device for determining annular pressure drop of horizontal well, electronic equipment and storage medium

Abstract

The application discloses a kind of horizontal well annular pressure drop determination method, device, electronic equipment and storage medium, comprising: obtaining and target wellhead corresponding drilling basic parameters, and based on drilling basic parameters Construction annular flow passage three-dimensional model;The annular flow passage three-dimensional model is grid division, and determine and the simulation parameter corresponding to annular flow passage three-dimensional model;Based on simulation parameter and the annular flow passage three-dimensional model after grid division determines the annular pressure drop gradient data under different working conditions;Based on the annular pressure drop gradient data under different working conditions determines dimensionless correction factor, and according to drilling basic parameters, determine reference annular pressure drop by theoretical calculation model;Based on dimensionless correction factor and reference annular pressure drop determines and target wellhead corresponding target annular pressure drop, according to target annular pressure drop optimization and target wellhead corresponding hydrodynamic parameter.Geometric model is simulated according to horizontal well, and the calculation precision of horizontal well annular pressure drop is improved.

Description

Technical Field

[0001] This invention relates to the field of oil and gas reservoir development and oil and gas well engineering technology, and in particular to a method, apparatus, electronic equipment and storage medium for determining the annular pressure drop of a horizontal well. Background Technology

[0002] During drilling of complex well structures such as deviated wells, extended reach wells, and horizontal wells, the drill string may rotate eccentrically within the wellbore, affecting the flow and circulating pressure loss of the annular drilling fluid. This, in turn, alters the equivalent circulating density (ECD) of the drilling fluid at the bottom of the well. Accurate prediction of annular frictional pressure drop is a crucial theoretical foundation for pressure-controlled drilling in complex well structures. Domestic and international scholars have conducted theoretical and experimental research on eccentric annular frictional pressure drop calculations, establishing various calculation models. However, all have limitations. For example, analytical models only consider single factors such as eccentricity, neglecting other factors like drill string rotation and displacement. Furthermore, a calculation model for annular pressure drop that conforms to actual field conditions has not yet been established. Experimental research demands more stringent precision in pressure gauges and operations, resulting in unsystematic experimental data and inconsistent understanding of patterns in existing literature. Regression models based on experimental data lack broad applicability, leading to unreasonable calculation results in field applications.

[0003] Numerical simulation has become an effective tool for studying annular pressure loss in horizontal wells. It can obtain detailed information on the microscopic flow of complex local fluids and can be combined with macroscopic laws obtained from experiments to evaluate or assist in the correction of theoretical and empirical models. However, existing technical solutions do not provide comprehensive sensitivity analysis of annular pressure drop, and the established geometric models are difficult to characterize real-world working conditions. Summary of the Invention

[0004] This invention provides a method, apparatus, electronic device, and storage medium for determining the annular pressure drop in horizontal wells. By establishing a geometric model that conforms to horizontal well drilling, rationally dividing the fluid domain, setting parameters, and determining the calculation method, the flow of drilling fluid in the annulus is simulated, providing a theoretical basis for multi-factor sensitivity analysis of the annular pressure drop in horizontal wells. This allows for the determination of a more accurate annular pressure drop in horizontal wells, and the optimization of drilling hydraulic parameters based on the annular pressure drop.

[0005] According to one aspect of the present invention, a method for determining the annular pressure drop in a horizontal well is provided, comprising:

[0006] Obtain the drilling basic parameters corresponding to the target wellhead, and construct a three-dimensional model of the annulus flow channel based on the drilling basic parameters;

[0007] The three-dimensional model of the annular flow channel is meshed, and the simulation parameters corresponding to the three-dimensional model of the annular flow channel are determined.

[0008] Based on the simulation parameters and the meshed three-dimensional model of the annular flow channel, the annular pressure drop gradient data under different working conditions were determined.

[0009] The dimensionless correction factor is determined based on the annular pressure drop gradient data under different operating conditions, and the benchmark annular pressure drop is determined by theoretical calculation model based on the drilling basic parameters.

[0010] The target annular pressure drop corresponding to the target wellhead is determined based on the dimensionless correction factor and the baseline annular pressure drop, so as to optimize the hydraulic parameters corresponding to the target wellhead according to the target annular pressure drop.

[0011] According to another aspect of the present invention, an apparatus for determining the annular pressure drop of a horizontal well is provided, comprising:

[0012] The geometric model building module is used to obtain the drilling basic parameters corresponding to the target wellhead and to build a three-dimensional model of the annulus flow channel based on the drilling basic parameters;

[0013] The simulation parameter setting module is used to mesh the three-dimensional model of the annular flow channel and determine the simulation parameters corresponding to the three-dimensional model of the annular flow channel.

[0014] The simulation module is used to determine the annular pressure drop gradient data under different operating conditions based on the simulation parameters and the three-dimensional model of the annular flow channel after mesh generation.

[0015] The reference annular pressure drop calculation module is used to determine the dimensionless correction factor based on annular pressure drop gradient data under different operating conditions, and to determine the reference annular pressure drop through a theoretical calculation model based on drilling basic parameters.

[0016] The target annular pressure drop calculation module is used to determine the target annular pressure drop corresponding to the target wellhead based on the dimensionless correction factor and the baseline annular pressure drop, so as to optimize the hydraulic parameters corresponding to the target wellhead according to the target annular pressure drop.

[0017] According to another aspect of the present invention, an electronic device is provided, the electronic device comprising:

[0018] At least one processor; and

[0019] A memory that is communicatively connected to at least one processor; wherein,

[0020] The memory stores a computer program that can be executed by at least one processor, such that the at least one processor is able to perform the method for determining the annular pressure drop of a horizontal well according to any embodiment of the present invention.

[0021] According to another aspect of the present invention, a computer-readable storage medium is provided, which stores computer instructions for causing a processor to execute a method for determining the annular pressure drop of a horizontal well according to any embodiment of the present invention.

[0022] The technical solution of this invention involves acquiring drilling baseline parameters corresponding to the target wellhead and constructing a three-dimensional annular flow channel model based on these parameters. The three-dimensional annular flow channel model is then meshed, and simulation parameters corresponding to the model are determined. Based on the simulation parameters and the meshed annular flow channel model, annular pressure drop gradient data under different operating conditions are determined. A dimensionless correction factor is determined based on the annular pressure drop gradient data under different operating conditions, and a baseline annular pressure drop is determined using a theoretical calculation model based on the drilling baseline parameters. Finally, a target annular pressure drop corresponding to the target wellhead is determined based on the dimensionless correction factor and the baseline annular pressure drop, thereby optimizing the hydraulic parameters corresponding to the target wellhead. Based on this technical solution, by establishing a geometric model suitable for horizontal well drilling, rationally dividing the fluid domain, setting parameters, and determining the calculation method, the flow of drilling fluid in the drilling annulus is simulated. This provides a theoretical basis for multi-factor sensitivity analysis of horizontal well annular pressure drop, thereby determining a more accurate horizontal well annular pressure drop and optimizing drilling hydraulic parameters based on the annular pressure drop.

[0023] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a flowchart of a method for determining the annular pressure drop in a horizontal well, provided in an embodiment of the present invention.

[0026] Figure 2 This is a schematic diagram of the geometric model of the inner tubular column provided in an embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram of the flow channel geometry model provided in an embodiment of the present invention;

[0028] Figure 4 This is a schematic diagram of the flow channel geometry model after meshing, provided in an embodiment of the present invention;

[0029] Figure 5 This is a flowchart of the annular pressure drop correction factor provided in an embodiment of the present invention;

[0030] Figure 6 This is a flowchart of a method for determining the annular pressure drop in a horizontal well, provided in an embodiment of the present invention.

[0031] Figure 7 This is a flowchart of the computation process for building an algorithm around the generalized Reynolds number, provided in an embodiment of the present invention.

[0032] Figure 8 This is a flowchart of the calculation process for building an algorithm around the friction factor, provided in an embodiment of the present invention.

[0033] Figure 9 This is a schematic diagram of the axial flow velocity cloud map at the cross section provided in an embodiment of the present invention;

[0034] Figure 10 This is a schematic diagram of the axial flow trace at the cross section provided in an embodiment of the present invention;

[0035] Figure 11 This is a schematic diagram of the flow velocity cloud map at the cross section and its distribution along the line provided in the embodiment of the present invention;

[0036] Figure 12 This is a schematic diagram illustrating the variation of static pressure along the Z-axis of the fluid domain model provided in an embodiment of the present invention;

[0037] Figure 13 A schematic diagram of a device for determining the annular pressure drop in a horizontal well, provided in an embodiment of the present invention;

[0038] Figure 14 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0039] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. 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 should fall within the scope of protection of the present invention.

[0040] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0041] Figure 1 This is a flowchart illustrating a method for determining the annular pressure drop in a horizontal well according to an embodiment of the present invention. This embodiment is applicable to situations where a three-dimensional geometric model corresponding to the target wellhead is established, and the annular pressure drop in a horizontal well is determined through simulation based on the three-dimensional geometric model. This method can be executed by a device for determining the annular pressure drop in a horizontal well, which can be implemented in hardware and / or software and can be configured in an electronic device. Figure 1 As shown, the method specifically includes the following steps:

[0042] S110. Obtain the drilling basic parameters corresponding to the target wellhead, and construct a three-dimensional model of the annulus flow channel based on the drilling basic parameters.

[0043] The target wellhead can be a horizontal well for which annular pressure drop calculations are to be performed. Basic drilling parameters can be understood as fundamental data characterizing wellbore size, drill string assembly, and drilling fluid properties. The annular flow channel 3D model is a three-dimensional geometric model used to represent the drilling fluid flow space.

[0044] Specifically, the drilling basic parameters corresponding to the target wellhead are obtained, and a three-dimensional model of the annulus flow channel is constructed based on the drilling basic parameters. For example, drilling basic parameters such as wellbore size, drill string assembly, and eccentricity of the target wellhead can be collected through the well site engineering data table, and the internal tubing string and annulus geometry can be drawn using three-dimensional modeling software. Boolean operations are used to obtain the three-dimensional model of the annulus flow channel and output a standard format file.

[0045] For example, drilling parameters are collected and analyzed to determine the necessary operating parameters for the simulation, such as wellbore size, drill string assembly, rotational speed, eccentricity, displacement, and drilling fluid rheological properties. Then, using Soliworks software, a simulation model is established. Figure 2The geometric model shown is created by first drawing the inner tubing circular geometry based on the wellbore dimensions and drill string assembly. This inner tubing circular geometry is then stretched into a boss shape to the actual length of the drill string, and this is designated as entity 1. Because sudden changes in flow channel dimensions can significantly impact fluid flow, the drill string should include at least: drill bit + rotary steering tool + connector + drill pipe. The annulus circular geometry should be drawn 3%-10% larger than the maximum outer diameter of the inner tubing (drill bit), and an eccentricity should be set. The eccentricity calculation formula can be expressed as: E = Where: E is the eccentricity; δ is the eccentricity, which is the distance between the drill bit and the two centers of the wellbore in the view along the wellbore axis, in meters; r w r is the radius of the wellbore, in meters (m). d Let be the maximum radius of the inner tubing, in meters. Perform a boss extrusion operation on the circular geometry of the annulus, extruding it until it is flush with the inner tubing; this is denoted as solid 2. Perform a Boolean operation on solid 1 and solid 2, subtracting solid 1 from solid 2. The resulting solid represents the flow channel of the fluid in the annulus, as shown below. Figure 3 As shown. Finally, save the geometry file as a .xt file.

[0046] S120. Mesh the three-dimensional model of the annular flow channel and determine the simulation parameters corresponding to the three-dimensional model of the annular flow channel.

[0047] Mesh generation is the process of discretizing a continuous geometric model into computational units. Simulation parameters are a set of parameters that control the flow field simulation, including boundary conditions, turbulence model, and fluid properties.

[0048] Specifically, the three-dimensional model of the annular flow channel is meshed, and the simulation parameters corresponding to the three-dimensional model of the annular flow channel are determined. For example, the three-dimensional model of the annular flow channel is imported into the simulation platform, volume meshing is performed and quality checks are conducted to ensure that the mesh distortion meets the calculation requirements. Boundary conditions, turbulence model, fluid material properties and motion reference system parameters are set in sequence to complete the simulation parameter configuration.

[0049] For example, a geometry file built in Solidworks software is imported into Ansys Fluent. The model is imported into the Ansys Fluent workbench, and the geometry file is edited using the Design Modeler. In the Design Modeler, the inlet and outlet of the annular flow channel are named: the inlet is the annulus at the bottom of the drill bit in the geometry model, named "inlet," and the outlet is named "outlet." Meshing is then performed in Ansys Fluent. Figure 4As shown, after the volume mesh is generated, a mesh check is performed. The average mesh distortion should be less than 0.25. The calculation parameters are set in Ansys Fluent. The parameter settings include (1) setting the inlet boundary condition to velocity inlet and the outlet boundary condition to pressure inlet; (2) selecting the SST k-omega model in the viscous turbulence model. Create a fluid material; (3) set it as an incompressible fluid with a constant fluid density. Select different rheological modes for the fluid viscosity according to the working parameters, or define the rheological mode by inputting an expression. Name the created fluid material mud; (4) set the element region conditions. Select the mud fluid created in the previous step as the material in the fluid domain, select the motion reference frame, set the origin coordinates of the rotation axis to x, y, z (0, 0, 0), the rotation axis direction to x, y, z (0, 0, 1), and set the rotation speed according to the working parameters. (5) set the boundary conditions. The wall surface is set to a standard roughness model, the inlet is a velocity inlet with fluid velocity set according to operating parameters, the outlet is a pressure outlet, the recirculation turbulence intensity is 5%, and the recirculation turbulence viscosity ratio is 10. After the above steps, further calculation control parameters are set: pseudo-time explicit relaxation factor is set to pressure 0.5, momentum 0.5, density 1, volume force 1, turbulent kinetic energy 0.75, specific dissipation rate 0.75, turbulent viscosity 1, energy 0.75, and residual standard is less than 0.00001. This step needs to be adjusted during the calculation process based on the convergence status. If the calculation becomes unstable or diverges, the relaxation factor needs to be reduced to pressure 0.2, momentum 0.2, turbulent kinetic energy 0.5, specific dissipation rate 0.5, and the convergence residual appropriately increased.

[0050] The technical solution of this invention ensures the stability and convergence of simulation calculations, avoids calculation divergence, and improves the accuracy of numerical simulation through high-quality mesh generation and standardized parameter configuration.

[0051] S130. Based on the simulation parameters and the meshed three-dimensional model of the annular flow channel, the annular pressure drop gradient data under different working conditions are determined.

[0052] The annular pressure drop gradient data can be understood as the pressure loss values ​​in the annular flow channel under different displacements, rotational speeds, and eccentricities. The simulation conditions consist of multiple sets of simulation calculation conditions combining different displacements, rotational speeds, and eccentricities. The simulation results can be the pressure and velocity field distribution data output from the flow field simulation.

[0053] Specifically, based on the simulation parameters and the three-dimensional model of the annular flow channel after mesh generation, the annular pressure drop gradient data under different working conditions are determined. For example, according to the mesh model and simulation parameters, multiple sets of simulation working conditions with different rotational speeds, displacements, and eccentricities are set, and then the flow field simulation calculation is started to output the pressure and velocity distribution results. Finally, pressure integration is performed at the specified section of the model to calculate the axial pressure difference and obtain the annular pressure drop gradient data for the corresponding working conditions.

[0054] Based on the above technology, the annular pressure drop gradient data under different working conditions are determined based on the simulation parameters and the three-dimensional model of the annular flow channel after mesh generation. This includes: setting the simulation working conditions based on the three-dimensional model of the annular flow channel after mesh generation and the simulation parameters; performing flow field simulation calculations based on the simulation working conditions to determine the simulation calculation results; and calculating the cross-sectional pressure integral and axial pressure difference based on the simulation calculation results to determine the annular pressure drop gradient data under the simulation working conditions.

[0055] Specifically, a mesh model and simulation parameters can be loaded into the simulation platform, and multiple sets of differentiated simulation conditions can be configured; iterative calculations can be run until convergence to obtain complete flow field simulation results; a target section can be created in the axial direction of the fluid domain, and the section pressure can be obtained through surface weighted integration, and the annular pressure drop gradient data can be obtained by calculating the section difference.

[0056] For example, the pressure-velocity coupling method is SIMPLEC, the discrete method pressure is PRESTO format, the gradient is Least Squares Cell Based, and the others are second-order upwind format. In the initialization settings, hybrid initialization is selected. The calculation is run, and the number of iterations is selected to be more than 1000 steps to facilitate observation of the calculation convergence and adjustment of parameters. After the calculation converges, post-processing analysis is performed.

[0057] It should be noted that the post-processing analysis includes: (1) Creating a plane, the plane is in the xy-axis direction and the plane position is in the z-axis direction. Multiple planes can be created to obtain the distribution of physical quantities such as pressure and velocity in the annulus radial direction at different drill bits in the geometric model. (2) On the created plane, perform surface weighted integration to obtain physical quantities such as velocity and pressure. Calculate between two planes to obtain physical quantities such as pressure drop gradient and velocity gradient at different drill bits in the geometric model. (3) Creating a radial straight line, the straight line direction is the xy plane and the position is determined by the z-axis. Multiple radial straight lines can be created to obtain the distribution of physical quantities such as pressure and velocity in the annulus radial direction. (4) Creating an axial straight line, the straight line direction is the z-axis and the position is determined by the x and y axes. Multiple axial straight lines can be created to obtain the distribution of physical quantities such as pressure and velocity in the axial direction. By changing the operating parameters such as rotational speed and displacement, and repeating the simulation mode, the annulus pressure drop gradient under different operating conditions with the same eccentricity can be obtained, and multi-factor sensitivity analysis can be performed. By changing the geometric model, setting different eccentricities, and repeating the simulation mode, the annular pressure drop gradient under different working conditions with different eccentricities can be obtained, and multi-factor sensitivity analysis can be performed.

[0058] The technical solution of this invention achieves accurate extraction of annular pressure drop through standardized simulation process and post-processing calculation, and the results are intuitive and quantifiable, meeting the needs of multi-factor sensitivity analysis.

[0059] S140. Determine the dimensionless correction factor based on the annular pressure drop gradient data under different working conditions, and determine the benchmark annular pressure drop through a theoretical calculation model based on the drilling basic parameters.

[0060] The dimensionless correction factor can be a ratio coefficient between the pressure drop under different operating conditions and the reference pressure drop, used to correct for the effects of rotation and eccentricity. The reference annular pressure drop can be understood as the reference value of the annular pressure drop under concentric, non-rotating operating conditions. The theoretical calculation model can be an analytical pressure drop calculation model based on fluid mechanics, including generalized Reynolds number logic and friction factor logic.

[0061] Specifically, a dimensionless correction factor is determined based on annular pressure drop gradient data under different operating conditions, and a benchmark annular pressure drop is determined through a theoretical calculation model based on drilling basic parameters. For example, concentric non-rotating operating condition data is extracted from multi-operating condition pressure drop data as the benchmark pressure drop; the initial correction factor is obtained by calculating the ratio of each operating condition pressure drop to the benchmark pressure drop, and the initial correction factor is fitted according to displacement and eccentricity to obtain a dimensionless correction factor. At the same time, the benchmark annular pressure drop is calculated using dual theoretical logic.

[0062] Based on the above technology, a dimensionless correction factor is determined based on annular pressure drop gradient data under different operating conditions, including: selecting annular pressure drop gradient data corresponding to the concentric non-rotating operating condition as the reference pressure drop data based on the annular pressure drop gradient data under different operating conditions; calculating the ratio between the reference pressure drop data and the annular pressure drop gradient data corresponding to each operating condition to obtain the initial correction factor; and classifying and fitting the initial correction factor according to displacement and eccentricity to obtain the dimensionless correction factor.

[0063] Specifically, the pressure drop data under the concentric operating condition with zero speed can be selected as the reference pressure drop data; the ratio of the annular pressure drop under the other operating conditions to the reference pressure drop is calculated to obtain the initial correction factor; the initial correction factor is then grouped according to different displacement ranges and eccentricity ranges, and polynomial fitting is performed on the initial correction factor to generate a dimensionless correction factor.

[0064] For example, the dimensionless annular pressure drop correction factor is the ratio of the annular pressure drop gradient at a certain speed under the same displacement and eccentricity to the reference annular pressure drop gradient (i.e., the annular pressure drop gradient at 0 speed and 0 eccentricity under this displacement). ;in, This represents the annular pressure drop gradient under the concentric, non-rotating operating condition for this displacement. The annular pressure drop gradient is given under the same eccentricity and different operating speeds for this displacement. The correction factors are as follows: (1) When the displacement V is 5L / s: =4.46×10⁻⁶N² - 5.58×10⁻⁴N + 1.0069; ② When E=10%, the prediction model is: =1.26×10⁻⁶N² - 2.39×10⁻⁴N + 0.98; ③ When E=20%, the prediction model is: =-7.07×10⁻⁷N² + 2.58×10⁻⁵N + 0.9482; ④ When E=30%, the prediction model is: =-1.91×10⁻⁶N²-2.82×10⁻⁴N+0.9187; ⑤ When E=40%, the prediction model is: =-1.29×10-7N2+5.33×10-5N+0.8746.

[0065] (2) When the displacement V is 8L / s: ① When E=0, the prediction model is: =3.41×10⁻⁶N² - 4.53×10⁻⁵N + 1.0003; ② When E=10%, the prediction model is: =3.11×10⁻⁶N² - 5.47×10⁻⁵N + 1.0045; ③ When E=20%, the prediction model is: =3.65×10⁻⁶N² - 3.65×10⁻⁵N + 0.9757; ④ When E=30%, the prediction model is: =3.12×10⁻⁶N² + 7.875.58×10⁻⁵N + 0.9505; ⑤ When E=40%, the prediction model is: =1.73×10-6N2+1.87×10-4N+0.9070.

[0066] (3) When the displacement V is 11 L / s: ① When E=0, the prediction model is: =5.08×10⁻⁶N² - 1.61×10⁻⁵N + 0.9984; ②The prediction model when E=10% is: =2.75×10⁻⁶N² - 5.03×10⁻⁵N + 1.0082; ③ When E=20%, the prediction model is: =3.11×10⁻⁶N² - 1.66×10⁻⁵N + 0.9807; ④ When E=30%, the prediction model is: =3.55×10⁻⁶N² + 2.30×10⁻⁵N + 0.9593; ⑤ When E=40%, the prediction model is: =3.69×10-6N2+3.26×10-5N+0.9189.

[0067] (4) When the displacement V is 14 L / s: ① When E=0, the prediction model is: =1.63×10⁻⁶N² - 2.78×10⁻⁵N + 1.0002; ② When E=10%, the prediction model is: =1.77×10⁻⁶N² - 1.35×10⁻⁵N + 0.9743; ③ When E=20%, the prediction model is: =1.62×10⁻⁶N² + 7.01×10⁻⁵N + 0.9490; ④ When E=30%, the prediction model is: =1.95×10⁻⁶N² + 1.36×10⁻⁴N + 0.9316; ⑤ When E=40%, the prediction model is: =2.41×10-6N2+1.42×10-4N+0.8958.

[0068] (5) When the displacement V is 17 L / s: ① When E=0, the prediction model is: =1.28×10⁻⁶N² - 1.0472×10⁻⁵N + 1.0001; ② When E=10%, the prediction model is: =1.38×10⁻⁶N² + 5.99×10⁻⁶N + 0.9745; ③ When E=20%, the prediction model is: =-1.44×10-5N2+0.0026N+0.8614; ④When E=30%, the prediction model is: =1.54×10⁻⁶N² + 1.53×10⁻⁴N + 0.9340; ⑤ When E=40%, the prediction model is: =1.21×10⁻⁶N² - 2.39×10⁻⁴N + 0.8992. Where: V is displacement, L / s; E is eccentricity, %; N is rotational speed, rev / min.

[0069] The technical solution of this invention eliminates discrete errors through classification fitting, forming a continuous and smooth correction factor model that can accurately reflect the influence of speed, eccentricity, and displacement on pressure drop.

[0070] S150. Based on the dimensionless correction factor and the baseline annular pressure drop, determine the target annular pressure drop corresponding to the target wellhead, so as to optimize the hydraulic parameters corresponding to the target wellhead according to the target annular pressure drop.

[0071] The target annular pressure drop can be the final annular pressure drop value calculated under the actual operating conditions at the target wellhead.

[0072] Specifically, the target annular pressure drop corresponding to the target wellhead is determined based on the dimensionless correction factor and the reference annular pressure drop. The hydraulic parameters corresponding to the target wellhead are then optimized based on the target annular pressure drop. By determining the target calculation point of the target wellhead, the corresponding eccentricity and displacement parameters are extracted, and the parameter intervals are determined. The target dimensionless correction factor is obtained through interpolation. The target correction factor is multiplied by the reference annular pressure drop to obtain the target annular pressure drop, which is used for hydraulic parameter optimization.

[0073] Based on the above technology, the target annular pressure drop corresponding to the target wellhead is determined based on the dimensionless correction factor and the benchmark annular pressure drop. This includes: determining the target calculation point corresponding to the target wellhead; determining the target eccentricity and target displacement based on the target calculation point; determining the target eccentricity interval and target displacement interval based on the target eccentricity interval and target displacement interval; determining the target dimensionless correction factor based on the target eccentricity interval, target displacement interval, and dimensionless correction factor; and multiplying the target dimensionless correction factor and the benchmark annular pressure drop to determine the target annular pressure drop.

[0074] The target calculation point can be understood as the designated location within the target well where the pressure drop to be calculated is to be determined. Target eccentricity and target displacement are the actual operational parameters for the target calculation point. Hydraulic parameters are optimization parameters such as displacement, pump pressure, and drill bit parameters that guide drilling operations.

[0075] Specifically, the target calculation point is located, the actual eccentricity and displacement are obtained, and the displacement range and eccentricity range to which it belongs are determined; in the dimensionless correction factor model, the target correction factor is obtained by bidirectional interpolation; the target correction factor is multiplied by the reference annular pressure drop to obtain the final target annular pressure drop.

[0076] For example, such as Figure 5 As shown, based on the characteristics of the well section where the calculation point is located (incline-increasing section, declination-decreasing section, or stabilizing section), and parameters such as well inclination angle, build-up rate, drill string size, wellbore size, and stabilizer size, the eccentricity E and displacement V are determined according to the drill string buckling theory, and the intervals [V1, V2] and [E1, E2] where displacement V and eccentricity E are located are found. The dimensionless correction factor for calculating displacement V1, eccentricity E1, and E2 using the appropriate prediction model is selected. , The dimensionless correction factor for the eccentricity E under the displacement V1 is calculated using interpolation. The dimensionless correction factors for displacement V2, eccentricity E1, and E2 are calculated using the appropriate prediction model. , The dimensionless correction factor for the eccentricity E under the displacement V2 is calculated using interpolation. Finally in and Dimensionless correction factor obtained by interpolation Based on theoretical calculation logic, Based on PN, the final annular pressure drop is calculated using the following formula: .

[0077] The technical solution of this invention involves acquiring drilling baseline parameters corresponding to the target wellhead and constructing a three-dimensional annular flow channel model based on these parameters. The three-dimensional annular flow channel model is then meshed, and simulation parameters corresponding to the model are determined. Based on the simulation parameters and the meshed annular flow channel model, annular pressure drop gradient data under different operating conditions are determined. A dimensionless correction factor is determined based on the annular pressure drop gradient data under different operating conditions, and a baseline annular pressure drop is determined using a theoretical calculation model based on the drilling baseline parameters. Finally, a target annular pressure drop corresponding to the target wellhead is determined based on the dimensionless correction factor and the baseline annular pressure drop, thereby optimizing the hydraulic parameters corresponding to the target wellhead. Based on this technical solution, by establishing a geometric model suitable for horizontal well drilling, rationally dividing the fluid domain, setting parameters, and determining the calculation method, the flow of drilling fluid in the drilling annulus is simulated. This provides a theoretical basis for multi-factor sensitivity analysis of horizontal well annular pressure drop, thereby determining a more accurate horizontal well annular pressure drop and optimizing drilling hydraulic parameters based on the annular pressure drop.

[0078] In one possible implementation of the present invention Figure 6 This is a flowchart illustrating a method for determining the annular pressure drop in a horizontal well, as provided in an embodiment of the present invention. The embodiment further describes a technical solution for determining the baseline annular pressure drop based on drilling fundamental parameters using a theoretical calculation model. Figure 6 As shown, the method includes:

[0079] S610. Based on the drilling basic parameters, the generalized Reynolds number calculation logic is used to perform iterative calculations to obtain the first reference annular pressure drop.

[0080] Among them, the generalized Reynolds number calculation logic is a pressure drop iterative calculation method based on rheological properties and generalized Reynolds number; the first reference annular pressure drop is the reference pressure drop value obtained by using generalized Reynolds number logic; the rheological model is the Herba fluid model, which characterizes the rheological properties of drilling fluid.

[0081] Specifically, based on the drilling fundamental parameters, iterative calculations are performed using the generalized Reynolds number calculation logic to obtain the first reference annular pressure drop. For example, a rheological model is selected based on the drilling fundamental parameters and the rheological parameters are calculated; the constitutive equation is substituted into the integral equation for fitting to obtain the fitting relationship; the effective equivalent diameter and convergence index are iteratively calculated using the initial flow behavior index; the pipe wall shear stress, generalized Reynolds number, and friction coefficient are calculated sequentially; and the rotation factor and joint factor are combined to obtain the first reference annular pressure drop.

[0082] Based on the above technology, the first reference annular pressure drop is obtained by iterative calculation using generalized Reynolds number calculation logic based on drilling basic parameters. This includes: selecting a rheological model and determining rheological parameters based on drilling basic parameters; substituting the rheological constitutive equation into the integral equation for fitting and determining the fitting result; iteratively calculating the effective equivalent diameter and convergent flow behavior index based on the fitting result and the initial flow behavior index; calculating the pipe wall shear stress, generalized Reynolds number, and Fanning friction coefficient based on the convergent flow behavior index; and calculating the first reference annular pressure drop based on the Fanning friction coefficient, rotation correction factor, and drill string joint correction factor.

[0083] The generalized Reynolds number calculation logic is an iterative solution method for the baseline pressure drop in annular flow of non-Newtonian fluids. The rheological model is a fluid constitutive model used to describe the relationship between drilling fluid shear stress and shear rate. Rheological parameters can be parameters characterizing fluid deformation properties, such as flow index, consistency coefficient, and yield value. The rheological constitutive equation can be understood as the mathematical expression equation corresponding to the rheological model. The integral equation is the Robinovich-Mona equation used to solve for annular wall shear stress. The fitting result can be understood as a polynomial fitting relationship between wall shear stress and flow velocity parameters. The initial flow behavior index is the initial value of the flow regime index set at the start of the iterative calculation. The effective equivalent diameter can be the equivalent calculated diameter after considering annular geometry and flow regime corrections. The convergent flow behavior index can be understood as the final flow behavior index after the iteration meets the accuracy requirements. The wall shear stress is the shear force experienced by the fluid at the annular wall. The generalized Reynolds number is a Reynolds number parameter adapted to non-Newtonian fluids. The Fanning friction coefficient is a coefficient characterizing fluid friction resistance. The rotation correction factor is a coefficient used to correct for the effect of drill string rotation on pressure drop. The drill string joint correction factor is a coefficient used to correct for local resistance of the joint. The first reference annular pressure drop is the theoretical reference pressure drop value under the concentric non-rotating condition.

[0084] Specifically, a suitable rheological model can be selected based on drilling parameters, and rheological parameters can be calculated. The rheological constitutive equation is substituted into the annular flow integral equation for integration and fitting with a third-order polynomial to obtain the fitting result. Starting from the initial flow behavior index, the effective equivalent diameter is iteratively calculated until the flow behavior index converges. The pipe wall shear stress, generalized Reynolds number, and Fanning friction coefficient are calculated using the converged index. The resistance correction is completed by combining the rotation correction factor and the drill string joint correction factor, and finally the first reference annular pressure drop is calculated.

[0085] For example, such as Figure 7 As shown, the algorithm is built around the generalized Reynolds number N, that is, the calculation logic includes: (1) Selecting the drilling fluid rheological mode and calculating its rheological parameters.

[0086] (2) Integrating the Robinovich-Mona equation.

[0087] Where V is the average upward velocity of drilling fluid in the annulus; D is the equivalent diameter of the annulus (D=D2−D1, D2 is the well diameter / casing inner diameter, D1 is the drill pipe outer diameter). τ is the shear stress at the annular pipe wall; τ is the shear stress of the fluid at a shear rate of γ; γ is the shear rate, which is the shear deformation rate of the fluid per unit time. This represents the shear rate at the corresponding pipe wall.

[0088] Based on the preferred rheological mode, the Herba mode, substituting the constitutive equation into the above equation, we obtain:

[0089] ;in, denoted as the yield stress in the Herba mode; k is the consistency coefficient in the Herba mode; n is the flow index in the Herba mode, used to reflect the degree to which the fluid deviates from a Newtonian fluid, and n<1 indicates a pseudoplastic fluid.

[0090] Integrating this equation, for different tube wall shear rates... The value can determine a pipe wall shear stress. With the 8V / D value, Ln can finally be obtained. Multiple sets of data for -Ln(8V / D).

[0091] (3) Based on the obtained Ln -Ln(8V / D) data, for Ln A third-order polynomial fit was performed with Ln(8V / D).

[0092] (4) Iterative calculation of N and D eff For a given flow rate Q, calculate the annular return velocity V of the drilling fluid.

[0093] Where Q is the displacement of the drilling pump, i.e., the flow rate per unit time; D2 is the inner diameter of the wellbore / casing; D1 is the outer diameter of the drill pipe; D dff This is the effective equivalent diameter for subsequent iterations.

[0094] Initially, let N=1. ①: Calculate and ;

[0095] Where σ = D1 / D2 is the ratio of drill pipe outer diameter to well diameter. N is the flow behavior index.

[0096] Where ω is a dimensionless coefficient derived from the integral result, used for subsequent determination of the effective diameter D. eff The calculation is as follows: n is the flow index of the Herba model, initially iterated with N=1.

[0097] ②: Mean eccentricity e av Replace n with N, e av Use e to calculate the eccentricity factor R.

[0098] Where, the eccentricity e is the distance between the drill pipe center and the wellbore center / the difference between the wellbore and drill pipe radii, i.e., e = eccentricity / ((D2−D1) / 2); the average eccentricity e av To account for the average eccentricity of the drill pipe after bending throughout the well section; the eccentricity factor R is used to correct for the influence of the eccentric annulus on the flow. Alternatively, it can be calculated using empirical formulas for eccentric annular flow.

[0099] ③: Calculate D eff :

[0100] ; where D h The hydraulic diameter of the annular cavity is defined as D. h =D2−D1.

[0101] Therefore, calculate 8V / D eff .

[0102] ④ Calculate N. Differentiate the third-order polynomial fitting function. The third-order polynomial fitting function at 8V / D... eff The derivative value at that point is the value of N.

[0103] Where N is the generalized flow behavior index, which reflects the logarithmic relationship between shear stress and shear rate.

[0104] ⑤ Return to iteration step ① and iterate using the N value from iteration step ④ until the N value is within the allowable error.

[0105] (5) After determining the value of N, based on the 8V / D of the last iteration eff The value was calculated using a third-order polynomial fitting function. .

[0106] (6) Calculate the generalized Reynolds number R eG The formula for calculating the generalized Reynolds number is: Where ρ is the drilling fluid density; V is the annular return velocity; This refers to the shear stress of the pipe wall; it should be noted that for non-Newtonian fluids, the generalized Reynolds number is used to determine the flow regime, and the critical value is usually [value missing]. =2100 (Laminar / Turbulent flow boundary).

[0107] (7) Calculate the Fanning friction coefficient f.

[0108] Under laminar flow conditions: Calculate the laminar friction coefficient f L =16 / R eG ;

[0109] In turbulent flow conditions: ;

[0110] in: ;in, For pipe wall roughness, it refers to the absolute roughness of the well wall and drill pipe surface, such as ε=0.045mm for steel rod.

[0111] (8) Calculate the rotation factor T and drill string joint factor F. con .

[0112] ;in, is the yield stress of the drilling fluid; n is the Herba fluidity index; It is the Reynolds number; It is a Taylor number.

[0113] ;in, This refers to the pressure loss per unit length of the joint section; This refers to the length of the joint section; This refers to the pressure loss per unit length of the drill pipe body section; This represents the total length of the drill pipe section.

[0114] (9) Calculate pressure loss. .

[0115] S620. Based on the drilling basic parameters, the friction factor calculation logic is used to perform iterative calculations to obtain the second reference annular pressure drop.

[0116] The friction factor calculation logic is based on a method for solving the annular pressure drop using flow regime discrimination and friction factor iteration. The second reference annular pressure drop is the reference annular pressure drop obtained by convergence under the friction factor logic.

[0117] Based on the above technology, a second benchmark annular pressure drop is obtained by iterative calculation using friction factor calculation logic based on drilling basic parameters. This includes: determining the critical discrimination value of the flow regime based on drilling basic parameters and calculating the Reynolds number and Taylor number; iteratively solving for the friction factor, eccentricity correction factor, and rotation correction factor based on the Reynolds number and Taylor number; calculating the current annular pressure loss based on the friction factor, eccentricity correction factor, rotation correction factor, and drill string joint correction factor; and iteratively calculating the second benchmark annular pressure drop based on the current annular pressure loss.

[0118] The critical discrimination value for flow regime is the critical Reynolds number, which distinguishes between laminar, transitional, and turbulent flow. The Reynolds number is a dimensionless number characterizing the fluid flow state. The Taylor number is a dimensionless number characterizing the intensity of disturbances caused by drill string rotation. The friction factor is a coefficient characterizing the frictional resistance of the annular flow. The eccentricity correction factor is a coefficient that corrects for the effect of eccentric annulus on pressure drop. The rotation correction factor is a coefficient that corrects for the effect of drill string rotation on pressure drop. The drill string joint correction factor is a coefficient that corrects for local resistance losses at the joint. The current annular pressure loss is the annular pressure loss value obtained from a single iteration calculation.

[0119] Specifically, the critical discrimination value of the flow regime can be calculated based on the basic drilling parameters, and the corresponding Reynolds number and Taylor number can be solved. The calculation results are substituted into the Colebrook-White equation to iteratively solve the friction factor, and then the eccentricity correction factor and rotation correction factor are calculated according to the flow regime. The current annular pressure loss is calculated by combining the friction factor and the three types of correction factors. The pressure loss difference is converged in a loop, and the stable second reference annular pressure drop is finally obtained.

[0120] For example, such as Figure 8 As shown, the algorithm built around the friction factor, namely the second calculation logic, includes: (1) determining the flow state.

[0121] ;

[0122] in: The Reynolds number represents the flow regime transitioning from laminar to moderate flow. The critical Reynolds number for laminar flow; The critical Reynolds number for turbulent flow; is the eccentricity correction factor; n is the flow index.

[0123] (2) Determine the Reynolds number and Taylor number at the current moment;

[0124] ;

[0125] in, The hydraulic diameter; The diameter of the open-hole shaft; The outer diameter of the drill string; It is the Reynolds number.

[0126] ;

[0127] Where: n is the flow index; k is the consistency coefficient; Angular velocity, It is a Taylor number.

[0128] (3) Calculate the Colebrook-White equation and iteratively calculate the friction factor f.

[0129] Where: F is the friction factor; Roughness; Re is the Reynolds number.

[0130] (4) Calculate the eccentricity factor R.

[0131] ;

[0132] in: (5) Calculate the rotation factor T. ;

[0133] When Re is other values, T needs to be calculated by linear interpolation. The applicable range is 46≤Ta≤830; when Ta<46, T=1.

[0134] (6) According to Calculate the influence factor of drill string joints .

[0135] (7) According to the formula Calculate the current annular pressure loss .

[0136] (8) Update the rheological parameters, friction factor and other parameters to prepare for the next iteration.

[0137] (9) P- If P0 is within the allowable error range, record the last annular pressure loss value, exit the loop, and obtain... .

[0138] The technical solution of this invention, through flow regime adaptive discrimination, multi-factor joint correction, and iterative convergence calculation, can accurately adapt to all flow regime conditions, significantly improving the calculation stability and applicability of the second reference annular pressure drop, and providing reliable theoretical calculation results for the reference pressure drop.

[0139] S630. Determine the reference annular pressure drop based on the first reference annular pressure drop and the second reference annular pressure drop.

[0140] Specifically, the first reference pressure drop calculated by the generalized Reynolds number logic and the second reference pressure drop calculated by the friction factor logic can be read; based on different flow channel sizes and operating conditions, the final reference annular pressure drop can be obtained.

[0141] For example, step 1 involves collecting and analyzing drilling parameters to determine the required operating parameters for the simulation, such as wellbore size, drill string assembly, rotational speed, eccentricity, displacement, and drilling fluid rheological properties.

[0142] Step 2: Using Soliworks software, a 25.28-meter-long simulated pipe string geometric model was created, consisting of a Φ118 mm PDC drill bit, a Φ93 mm rotary guide tool, a Φ73 mm drill rod, and a Φ105 mm connector.

[0143] Step 2, establishing the geometric model, includes the following steps:

[0144] (1) Based on the wellbore size and drill string assembly, the circular geometry of the inner tubing string was first drawn. A simulated tubing string with a length of 25.28 meters was established, consisting of a Φ118 mm PDC drill bit, a Φ93 mm rotary steerable tool, a Φ73 mm drill pipe, and a Φ105 mm connector.

[0145] (2) Perform a tufting boss operation on the drawn inner tube circular geometry, tufting it to the actual length of the drill bit, and record it as entity 1.

[0146] (3) Draw the geometry of the annulus, set as an annulus of Φ133 mm with eccentricity of 0%.

[0147] (4) Perform a stretching boss operation on the annular circular geometry until it is flush with the inner column, and denote it as solid 2.

[0148] (5) Perform a Boolean operation on entity 1 and entity 2, subtracting entity 1 from entity 2. The resulting entity is the flow channel of the fluid in the annulus. Save the geometry file as a .xt file.

[0149] (6) Based on the above steps (1)-(5), establish models with eccentricity of 10%, 20%, 30% and 40% in sequence.

[0150] Step 3: Import the geometry files created in Solidworks into Ansys Fluent. Import the model into the Ansys Fluent workbench and edit the geometry files using Design Modeler.

[0151] Step 4: In Design Modeler, name the inlet and outlet of the annular flow channel. The inlet is the annular space at the bottom of the geometric model at the drill bit, named inlet, and the outlet is named outlet.

[0152] Step 5: Mesh the volume in Ansys Fluent. After the volume mesh is complete, perform a mesh check. A total of 245,131 faces were meshed, with a maximum twist of 0.2174 and a maximum aspect ratio of 16.57. A total of 546,482 control volume meshes were meshed, with a minimum orthogonality quality of 0.3056 and a maximum aspect ratio of 5.89. There were no isolated meshes. The maximum twist of the mesh was 0.6944, the minimum twist was 0.0029, and the average twist was 0.0476. The mesh quality is excellent and meets Fluent's mesh quality requirements.

[0153] Step 6: Configure the calculation parameters in Ansys Fluent.

[0154] Step 6, parameter settings, includes the following steps:

[0155] (1) The inlet boundary condition is set to velocity inlet and the outlet boundary condition is set to pressure inlet.

[0156] (2) Select the SST k-omega model in the viscous turbulence model.

[0157] (3) Based on the field drilling fluid performance data, a fluid material was created. In this creation, the fluid was set to be incompressible with a constant density of 1100 kg / m3 and a viscosity of 0.058 Pa·s selected from the Herbart rheological model. The created fluid material was named mud.

[0158] (4) Set the unit region conditions. Select the material as the mud fluid created in the previous step in the fluid domain, select the motion reference frame, set the origin coordinates of the rotation axis to x,y,z(0,0,0), the rotation axis direction to x,y,z(0,0,1), and set the rotation speed to 0 rev / min, 30 rev / min, 60 rev / min, 90 rev / min, and 120 rev / min in sequence.

[0159] (5) Set boundary conditions. The wall surface is set to a standard roughness model, the inlet is a velocity inlet, and the displacement is set to 5 L / s, 8 L / s, 11 L / s, 14 L / s and 17 L / s in sequence. According to the set displacement and annular size, the inlet velocity is 0.139 m / s, 0.222 m / s, 0.458 m / s and 0.556 m / s respectively. The outlet is a pressure outlet, the gauge pressure is atmospheric pressure, the recirculation turbulence intensity is 5% and the recirculation turbulence viscosity ratio is 10.

[0160] Step 7: Set the calculation control parameters. The pseudo-time explicit relaxation factor is set to: pressure 0.5, momentum 0.5, density 1, body force 1, turbulent kinetic energy 0.75, specific dissipation rate 0.75, turbulent viscosity 1, energy 0.75, and residual standard less than 0.00001. This step needs to be adjusted during the calculation process based on the convergence status. If the calculation becomes unstable or diverges, the relaxation factor needs to be reduced to: pressure 0.2, momentum 0.2, turbulent kinetic energy 0.5, specific dissipation rate 0.5, and the convergence residual appropriately increased.

[0161] Step 8: Calculation method settings. Select SIMPLEC for the pressure-velocity coupling method, PRESTO format for the discrete method pressure, Least Squares Cell Based for the gradient, and second-order upwind scheme for the others.

[0162] Step 9: Initialization settings, select Hybrid Initialization.

[0163] Step 10: Run the calculation, selecting more than 1000 iterations to observe the convergence of the calculation and adjust the parameters.

[0164] Step 11: After convergence, perform post-processing analysis.

[0165] Step 11 post-processing analysis includes the following steps:

[0166] (1) A cross section is established 12 m from the model axis. This is the cross section of the 73 mm drill pipe in the drill assembly, with the plane along the xy-axis and the plane position along the z-axis. The axial velocity contour plot at this cross section is as follows: Figure 9 Flow trace diagram as follows Figure 10 .

[0167] (2) Create planes at both ends of the simulated tubing model, perform surface-weighted integration to obtain physical quantities such as velocity and pressure, and perform calculations between the two planes to obtain physical quantities such as pressure drop gradient and velocity gradient at different drill bits in the geometric model. The pressure drop gradient is calculated to be 120.5886 Pa / m.

[0168] (3) Create a radial straight line, with the direction of the line in the xy plane and its position determined by the z-axis. Establish a line from the narrow gap to the wide gap at the 0.1 m (drill bit), 5 m (MWD), 12 m (drill pipe), and 15 m (joint) sections, and obtain and plot the velocity distribution along this line as shown below. Figure 11 .

[0169] (4) Create an axial straight line with the z-axis as its direction and its position determined by the x and y axes. The simulation results of the drilling fluid static pressure variation along the Z-axis of the fluid domain model are shown in [reference needed]. Figure 12 .

[0170] By changing different eccentricity models, different speeds, and different displacements, and repeating steps 6 to 11, the pressure drop gradients of different eccentricity annular models at different speeds and different displacements are obtained.

[0171] Step 12: Calculate the dimensionless annular pressure drop correction factor, which is the ratio of the annular pressure drop gradient at a certain speed under the same displacement and eccentricity to the reference annular pressure drop gradient (i.e., the annular pressure drop gradient when the speed is 0 and the eccentricity is 0 under this displacement).

[0172]

[0173] This represents the annular pressure drop gradient under the concentric, non-rotating operating condition for this displacement.

[0174] This represents the annular pressure drop gradient under different operating speeds with the same eccentricity for this displacement.

[0175] Step 13: Program and calculate Logic 1 and Logic 2.

[0176] Step 14: Based on the drilling history data of a certain well in a certain oil field, the main input data parameters are shown in Table 1.

[0177]

[0178] The calculation results are shown in Table 2:

[0179]

[0180] The technical solution of this invention uses Ansys Fluent to construct a geometric model and performs simulation based on the drilling site conditions. The resulting annular pressure drop gradient correction factor is of great significance for drilling hydraulic analysis and hydraulic parameter optimization design.

[0181] The technical solution of this invention is based on the basic physical control equations, thus providing more realistic and reliable results. Its main advantage is that the research cost is much lower than other methods, and it is also less time-consuming than experimental methods. In addition, it can provide a visualized result, obtaining more flow details of complex geometries.

[0182] Existing CFD technologies often employ oversimplified models of actual drilling operations, failing to accurately simulate the impact of channel geometry on fluid flow. The present invention employs a more complex geometric model, closely reflecting real-world conditions, and its mesh design meets both simulation and computational requirements. Furthermore, existing CFD technologies primarily analyze single influencing factors such as annular pressure drop, resulting in limited analytical methods and insufficient adaptability of the obtained results. This patented technology proposes sensitivity analysis methods for displacement, rotational speed, and eccentricity.

[0183] The technical solution of this invention provides a more reasonable setting of calculation parameters and control of the calculation process, resulting in good calculation convergence and obtaining results that conform to the laws of hydraulics. It can provide a certain theoretical basis for the optimization design of hydraulic parameters in field drilling.

[0184] The technical solution of this invention is based on the correction factor obtained by Ansys Fluent simulation, which has wider applicability. It also proposes an annular pressure drop correction method that classifies annular pressure drop by eccentricity and displacement, which more accurately describes the main controlling factors of horizontal well annular pressure drop and more accurately reflects the influence of the main controlling factors on the final calculation results.

[0185] The technical solution of this invention innovatively proposes two calculation logics for calculating the annular pressure drop of horizontal wells, which has a wider applicability. When facing more complex working conditions with well structure, well trajectory, and working fluid rheology, there are more calculation path options, which can provide more references for horizontal well field construction.

[0186] Figure 13 This is a schematic diagram of a device for determining the annular pressure drop in a horizontal well, provided as an embodiment of the present invention. Figure 13 As shown, the device includes: a geometric model establishment module 1310, a simulation parameter setting module 1320, a simulation module 1330, a reference annular pressure drop calculation module 1340, and a target annular pressure drop calculation module 1350.

[0187] The geometric model building module 1310 is used to obtain the drilling basic parameters corresponding to the target wellhead and to build a three-dimensional model of the annulus flow channel based on the drilling basic parameters.

[0188] The simulation parameter setting module 1320 is used to mesh the three-dimensional model of the annular flow channel and determine the simulation parameters corresponding to the three-dimensional model of the annular flow channel.

[0189] Simulation module 1330 is used to determine the annular pressure drop gradient data under different working conditions based on simulation parameters and the three-dimensional model of the annular flow channel after mesh generation.

[0190] The reference annular pressure drop calculation module 1340 is used to determine the dimensionless correction factor based on annular pressure drop gradient data under different working conditions, and to determine the reference annular pressure drop through a theoretical calculation model based on drilling basic parameters.

[0191] The target annular pressure drop calculation module 1350 is used to determine the target annular pressure drop corresponding to the target wellhead based on the dimensionless correction factor and the reference annular pressure drop, so as to optimize the hydraulic parameters corresponding to the target wellhead according to the target annular pressure drop.

[0192] Based on the above technical solution, the reference annular pressure drop calculation module is used to select the annular pressure drop gradient data corresponding to the concentric non-rotating working condition as the reference pressure drop data based on the annular pressure drop gradient data under different operating conditions; calculate the ratio between the reference pressure drop data and the annular pressure drop gradient data corresponding to each operating condition to obtain the initial correction factor; and obtain the dimensionless correction factor by classifying and fitting according to displacement and eccentricity based on the initial correction factor.

[0193] Based on the above technical solution, the reference annular pressure drop calculation module is used to perform iterative calculations based on drilling basic parameters using generalized Reynolds number calculation logic to obtain the first reference annular pressure drop; to perform iterative calculations based on drilling basic parameters using friction factor calculation logic to obtain the second reference annular pressure drop; and to determine the reference annular pressure drop based on the first reference annular pressure drop and the second reference annular pressure drop.

[0194] Based on the above technical solution, the benchmark annular pressure drop calculation module is used to select a rheological model and determine rheological parameters based on the drilling basic parameters, substitute the rheological constitutive equation into the integral equation for fitting and determine the fitting result; iteratively calculate the effective equivalent diameter and convergent flow behavior index based on the fitting result and the initial flow behavior index; calculate the pipe wall shear stress, generalized Reynolds number and Fanning friction coefficient based on the convergent flow behavior index; and calculate the first benchmark annular pressure drop based on the Fanning friction coefficient, rotation correction factor and drill string joint correction factor.

[0195] Based on the above technical solution, the benchmark annular pressure drop calculation module is used to determine the critical discrimination value of the flow regime based on the basic drilling parameters, and to calculate the Reynolds number and Taylor number; to iteratively solve the friction factor, eccentricity correction factor and rotation correction factor based on the Reynolds number and Taylor number; to calculate the current annular pressure loss based on the friction factor, eccentricity correction factor, rotation correction factor and drill string joint correction factor; and to iteratively calculate and determine the second benchmark annular pressure drop based on the current annular pressure loss.

[0196] Based on the above technical solution, the simulation module is used to simulate the simulation conditions based on the three-dimensional model of the annular flow channel after mesh division and the simulation parameter settings, perform flow field simulation calculations based on the simulation conditions to determine the simulation calculation results, and calculate the annular pressure drop gradient data of the simulation conditions by performing cross-sectional pressure integral and axial pressure difference calculations based on the simulation calculation results.

[0197] Based on the above technical solution, the target annular pressure drop calculation module is used to determine the target calculation point corresponding to the target wellhead, and to determine the target eccentricity and target displacement based on the target calculation point; to determine the target eccentricity interval and target displacement interval based on the target eccentricity interval, target displacement interval and dimensionless correction factor; and to calculate the target annular pressure drop by multiplying the target dimensionless correction factor and the benchmark annular pressure drop.

[0198] The technical solution of this invention involves acquiring drilling baseline parameters corresponding to the target wellhead and constructing a three-dimensional annular flow channel model based on these parameters. The three-dimensional annular flow channel model is then meshed, and simulation parameters corresponding to the model are determined. Based on the simulation parameters and the meshed annular flow channel model, annular pressure drop gradient data under different operating conditions are determined. A dimensionless correction factor is determined based on the annular pressure drop gradient data under different operating conditions, and a baseline annular pressure drop is determined using a theoretical calculation model based on the drilling baseline parameters. Finally, a target annular pressure drop corresponding to the target wellhead is determined based on the dimensionless correction factor and the baseline annular pressure drop, thereby optimizing the hydraulic parameters corresponding to the target wellhead. Based on this technical solution, by establishing a geometric model suitable for horizontal well drilling, rationally dividing the fluid domain, setting parameters, and determining the calculation method, the flow of drilling fluid in the drilling annulus is simulated. This provides a theoretical basis for multi-factor sensitivity analysis of horizontal well annular pressure drop, thereby determining a more accurate horizontal well annular pressure drop and optimizing drilling hydraulic parameters based on the annular pressure drop.

[0199] The device for determining the annular pressure drop of a horizontal well provided in this embodiment of the invention can execute the method for determining the annular pressure drop of a horizontal well provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects of the method.

[0200] Figure 14A schematic diagram of an electronic device 10, which can be used to implement embodiments of the present invention, is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices (e.g., helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0201] like Figure 14 As shown, the electronic device 10 includes at least one processor 11 and a memory, such as a read-only memory (ROM) 12 or a random access memory (RAM) 13, communicatively connected to the at least one processor 11. The memory stores computer programs executable by the at least one processor. The processor 11 can perform various appropriate actions and processes based on the computer program stored in the ROM 12 or loaded from storage unit 18 into the RAM 13. The RAM 13 can also store various programs and data required for the operation of the electronic device 10. The processor 11, ROM 12, and RAM 13 are interconnected via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0202] Multiple components in electronic device 10 are connected to I / O interface 15, including: input unit 16, such as keyboard, mouse, etc.; output unit 17, such as various types of displays, speakers, etc.; storage unit 18, such as disk, optical disk, etc.; and communication unit 19, such as network card, modem, wireless transceiver, etc. Communication unit 19 allows electronic device 10 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0203] Processor 11 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, digital signal processors (DSPs), and any suitable processor, controller, microcontroller, etc. Processor 11 performs the various methods and processes described above, such as the method for determining the annular pressure drop in a horizontal well.

[0204] In some embodiments, the method for determining the annular pressure drop of a horizontal well may be implemented as a computer program tangibly contained in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program may be loaded and / or installed on electronic device 10 via ROM 12 and / or communication unit 19. When the computer program is loaded into RAM 13 and executed by processor 11, one or more steps of the method for determining the annular pressure drop of a horizontal well described above may be performed. Alternatively, in other embodiments, processor 11 may be configured to perform the method for determining the annular pressure drop of a horizontal well by any other suitable means (e.g., by means of firmware).

[0205] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, 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), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0206] Computer programs used to implement the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the processor, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be performed. The computer programs may be executed entirely on a machine, partially on a machine, or as a standalone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0207] In the context of this invention, a computer-readable storage medium can be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, apparatus, or device. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination thereof. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. 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 thereof.

[0208] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the electronic device. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0209] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or middleware components (e.g., application servers), or frontend components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., communication networks). Examples of communication networks include local area networks (LANs), wide area networks (WANs), blockchain networks, and the Internet.

[0210] A computing system can include clients and servers. Clients and servers are generally located far apart and typically interact through communication networks. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or cloud host, which is a hosting product within the cloud computing service system to address the shortcomings of traditional physical hosts and VPS services, such as high management difficulty and weak business scalability.

[0211] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0212] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for determining the annular pressure drop in a horizontal well, characterized in that, include: Obtain the drilling basic parameters corresponding to the target wellhead, and construct a three-dimensional model of the annulus flow channel based on the drilling basic parameters; The three-dimensional model of the annular flow channel is meshed, and the simulation parameters corresponding to the three-dimensional model of the annular flow channel are determined. Based on the simulation parameters and the meshed three-dimensional model of the annular flow channel, the annular pressure drop gradient data under different working conditions are determined. The dimensionless correction factor is determined based on the annular pressure drop gradient data under the different working conditions, and the benchmark annular pressure drop is determined by a theoretical calculation model based on the drilling basic parameters. Based on the dimensionless correction factor and the baseline annular pressure drop, the target annular pressure drop corresponding to the target wellhead is determined, so as to optimize the hydraulic parameters corresponding to the target wellhead according to the target annular pressure drop.

2. The method according to claim 1, characterized in that, The determination of the dimensionless correction factor based on the annular pressure drop gradient data under the different operating conditions includes: Based on the annular pressure drop gradient data under the different operating conditions, the annular pressure drop gradient data corresponding to the concentric non-rotating operating condition is selected as the benchmark pressure drop data. The initial correction factor is obtained by calculating the ratio between the baseline pressure drop data and the annular pressure drop gradient data corresponding to each operating condition. The dimensionless correction factor is obtained by classifying and fitting the initial correction factor according to displacement and eccentricity.

3. The method according to claim 1, characterized in that, The determination of the baseline annular pressure drop based on the drilling baseline parameters using a theoretical calculation model includes: Based on the aforementioned drilling parameters, iterative calculations were performed using generalized Reynolds number calculation logic to obtain the first reference annular pressure drop. Based on the aforementioned drilling parameters, iterative calculations were performed using friction factor calculation logic to obtain the second benchmark annular pressure drop. The reference annular pressure drop is determined based on the first reference annular pressure drop and the second reference annular pressure drop.

4. The method according to claim 3, characterized in that, The first baseline annular pressure drop is obtained by iterative calculation using generalized Reynolds number calculation logic based on the drilling fundamental parameters, including: Based on the drilling parameters, a rheological model is selected and the rheological parameters are determined. The rheological constitutive equation is substituted into the integral equation for fitting, and the fitting result is determined. The effective equivalent diameter and the convergent flow behavior index are iteratively calculated based on the fitting results and the initial flow behavior index. The pipe wall shear stress, generalized Reynolds number and Fanning friction coefficient are calculated based on the convergent flow behavior index. The first reference annular pressure drop is calculated based on the Fanning friction coefficient, rotation correction factor, and drill string joint correction factor.

5. The method according to claim 3, characterized in that, The second baseline annular pressure drop is obtained by iterative calculation using friction factor calculation logic based on the drilling baseline parameters, including: Based on the aforementioned drilling parameters, the critical flow regime discrimination value is determined, and the Reynolds number and Taylor number are calculated. The friction factor, eccentricity correction factor, and rotation correction factor are solved iteratively based on the Reynolds number and Taylor number. The current annular pressure loss is calculated based on the friction factor, the eccentricity correction factor, the rotation correction factor, and the drill string joint correction factor. The second reference annular pressure drop is determined by iterative calculation based on the current annular pressure loss.

6. The method according to claim 1, characterized in that, The determination of annular pressure drop gradient data under different operating conditions based on the simulation parameters and the meshed annular flow channel 3D model includes: Based on the three-dimensional model of the annular flow channel after mesh generation and the simulation parameter settings, the simulation conditions are simulated, and the flow field simulation calculation is performed based on the simulation conditions to determine the simulation results. Based on the simulation results, the annular pressure drop gradient data of the simulated working condition is determined by calculating the cross-sectional pressure integral and the axial pressure difference.

7. The method according to claim 1, characterized in that, The determination of the target annular pressure drop corresponding to the target wellhead based on the dimensionless correction factor and the baseline annular pressure drop includes: Determine the target calculation point corresponding to the target wellhead, and determine the target eccentricity and target discharge rate based on the target calculation point; The target eccentricity range and the target displacement range are determined based on the target eccentricity and the target displacement; The target dimensionless correction factor is determined based on the target eccentricity range, the target displacement range, and the dimensionless correction factor. The target annular pressure drop is determined by multiplying the target dimensionless correction factor and the reference annular pressure drop.

8. A device for determining the annular pressure drop in a horizontal well, characterized in that, include: The geometric model building module is used to obtain the drilling basic parameters corresponding to the target wellhead and to construct a three-dimensional model of the annulus flow channel based on the drilling basic parameters. The simulation parameter setting module is used to mesh the three-dimensional model of the annular flow channel and determine the simulation parameters corresponding to the three-dimensional model of the annular flow channel. The simulation module is used to determine the annular pressure drop gradient data under different operating conditions based on the simulation parameters and the three-dimensional model of the annular flow channel after mesh division. The reference annular pressure drop calculation module is used to determine the dimensionless correction factor based on the annular pressure drop gradient data under the different working conditions, and to determine the reference annular pressure drop through a theoretical calculation model based on the drilling basic parameters. The target annular pressure drop calculation module is used to determine the target annular pressure drop corresponding to the target wellhead based on the dimensionless correction factor and the reference annular pressure drop, so as to optimize the hydraulic parameters corresponding to the target wellhead according to the target annular pressure drop.

9. An electronic device, characterized in that, The electronic device includes: At least one processor; and A memory communicatively connected to the at least one processor; wherein, The memory stores a computer program that can be executed by the at least one processor, the computer program being executed by the at least one processor to enable the at least one processor to perform the method for determining the annular pressure drop of a horizontal well as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that, when executed by a processor, implement the method for determining the annular pressure drop of a horizontal well as described in any one of claims 1-7.

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