Rotary steering test method and system for simulating underground drilling fluid circulation in workshop

Abstract

The invention belongs to the technical field of petroleum and natural gas drilling engineering, and relates to a rotary steering test method and system for simulating underground drilling fluid circulation in a workshop. The method comprises the following steps: firstly, determining a dynamic fingerprint and a tolerance band of a circulation channel of a target well section, wherein the dynamic fingerprint comprises a time domain step and a frequency domain phase index; constructing a test loop of a series-connected adjustable hydraulic dynamic equivalent module, wherein the module comprises a containing cavity, a throttling unit and an inertia pipe unit to regulate and control flexibility, damping and inertia; applying flow disturbance and collecting flow pressure data to obtain a current dynamic fingerprint; comparing the tolerance band to iteratively adjust module parameters until the fingerprint reaches the standard; and after locking the parameters, carrying out function testing. The problem that traditional testing is disjointed with underground working conditions can be solved, testing accuracy and reliability are improved, testing cost is reduced, and testing requirements of different well sections are met.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas drilling engineering technology, specifically relating to a rotary steering test method and system for simulating downhole drilling fluid circulation in a workshop. Background Technology

[0002] The Rotary Steerable System (RSS) is a core piece of equipment in directional drilling engineering for achieving precise wellbore trajectory control. The responsiveness of its steering actuator, the pressure regulation accuracy of its valve control system, and the signal stability of its measurement feedback module are all directly related to the dynamic state of the drilling fluid circulation system. Before actual drilling operations, to reduce downhole failure risks and control engineering costs, the industry commonly adopts the method of setting up a drilling fluid circulation test loop in the workshop to conduct functional verification, parameter debugging, and performance evaluation of the RSS.

[0003] However, the actual structure and hydraulic characteristics of the downhole drilling fluid circulation channel are complex: it consists of a drill string cavity that can extend for thousands of meters, the internal flow channels of the RSS tool, the annular return flow channel formed by the drill string and the wellbore, and the surface manifold. It possesses three significant hydraulic characteristics: inertia, friction and local damping characteristics, and compressibility. Inertia manifests as a significant lag in the acceleration and / or deceleration processes of fluid flowing within long channels; friction and local damping characteristics manifest as energy dissipation caused by fluid-to-pipe friction, internal viscous losses, and abrupt changes in local flow channels; compressibility stems from dissolved gases in the drilling fluid, elastic deformation of the drill string and piping, and exhibits an energy storage effect. These characteristics cause the downhole circulation channel to produce specific dynamic responses to flow disturbances (such as drilling pump displacement adjustments, pump pressure pulsations, and RSS internal valve switching). For example, when the displacement of the drilling pump increases by a step, the downhole standpipe pressure will not change immediately. It will take a period of time to rise to reach a value close to the steady state. During this period, there may be an overshoot exceeding the final steady state pressure. Then, it tends to stabilize through short-term oscillations, and the phase lag of this process is significant.

[0004] In contrast, workshop test loops are limited by space constraints and equipment layout, resulting in the following limitations: First, the loop length is short (typically only a few meters to tens of meters, far shorter than the thousands of meters of underground channels); second, volumetric flexibility is low (pipelines are mostly rigid steel pipes, with small drilling fluid storage capacity and weak compressibility); third, damping distribution is uniform and the value is small (fewer pipe bends and valves, resulting in much lower friction loss along the pipe compared to underground); and fourth, there are significant differences in pump type and installation method (workshops mostly use small variable frequency pumps, which have different pulsation characteristics than high-power drilling pumps used underground). These structural and parameter differences lead to distinctly different hydraulic dynamic characteristics between workshop loops and underground channels—for the same flow disturbance, workshop loops have shorter pressure response rise times, smaller overshoot, faster settling times, and significantly smaller phase lag compared to underground channels.

[0005] In existing technologies, workshop RSS testing schemes generally focus on reproducing static or quasi-static operating conditions. For example, adjusting the pump displacement to match the steady-state flow rate in the loop with the downhole flow rate, or adjusting the throttle valve to match the steady-state pressure drop with the downhole value. However, the reproduction results obtained by existing technologies (such as steady-state pressure drop and flow rate) are all static parameters. If static parameters are used as the benchmark for workshop testing, ignoring the differences in dynamic response characteristics, the following problems will arise: Valve control parameters (such as valve opening and closing thresholds and action speeds), control gains (such as PID control parameters), and stability assessment conclusions obtained by RSS debugging and optimization in the workshop often exhibit response lag (delayed action of the actuator after the command is issued), pressure oscillation (continuous fluctuation of system pressure that cannot be stabilized), and false triggering of control signals (unexpected valve action) when applied to actual downhole operating conditions. In some cases, the performance observed in workshop testing may even fail to be reproduced. This not only renders workshop testing meaningless but may also lead to serious drilling accidents such as stuck pipe and loss of wellbore trajectory control, significantly increasing non-productive time. Summary of the Invention

[0006] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution: Firstly, a rotary steering test method for simulating downhole drilling fluid circulation in a workshop is proposed, comprising the following steps: Determine the dynamic fingerprint and target tolerance band of the downhole circulation channel in the target well section; wherein, the dynamic fingerprint includes a set of characteristic commands used to quantitatively characterize the pressure response of the circulation channel to flow disturbances; the set of characteristic commands includes time-domain step index and frequency-domain phase index; A workshop circulation test loop is constructed; an adjustable hydraulic dynamic equivalent module is connected in series in the workshop circulation test loop; a flow detection device is arranged in the upstream main channel of the adjustable hydraulic dynamic equivalent module, and a pressure detection device is arranged in the downstream main channel of the adjustable hydraulic dynamic equivalent module; the adjustable hydraulic dynamic equivalent module includes an adjustable equivalent cavity unit, an adjustable flow unit, and a replaceable equivalent inertia pipe section connected in series; the adjustable equivalent cavity unit is used to adjust the equivalent flexibility of the workshop circulation test loop, the adjustable flow unit is used to adjust the equivalent damping of the workshop circulation test loop, and the replaceable equivalent inertia pipe section is used to adjust the equivalent inertia of the workshop circulation test loop; The flow perturbation excitation in the fluid in the workshop circulation test loop is repeatedly applied, and the flow response data of the workshop circulation test loop is collected using a flow detection device and the pressure response data of the workshop circulation test loop is collected using a pressure detection device. Based on the collected flow response data and pressure response data, the current dynamic fingerprint of the workshop cyclic test loop is obtained; Compare the current dynamic fingerprint of the workshop cycle test loop with the target tolerance band. If the current dynamic fingerprint does not fall into the tolerance band, adjust the parameters of the adjustable equivalent cavity unit, the adjustable flow unit and the replaceable equivalent inertial tube section iteratively according to the deviation results until the dynamic fingerprint indicators all fall into the target tolerance band. Lock all adjustment parameters of the adjustable hydraulic dynamic equivalent module, perform functional tests on the rotary guide system under all locked adjustment parameters, and record the test data and module locking parameters.

[0007] Secondly, a rotary steering test system for simulating downhole drilling fluid circulation in a workshop is proposed for performing the rotary steering test method as described in the first aspect; the rotary steering test system includes: The fluid circulation subsystem includes a storage tank, a circulation pump, an adjustable hydraulic dynamic equivalent module, an RSS tool and its equivalent section, and a return pipeline connected in sequence. The data acquisition subsystem includes a flow detection device installed in the upstream main channel of the adjustable hydraulic dynamic equivalent module, a pressure detection device installed in the downstream main channel of the adjustable hydraulic dynamic equivalent module, and a synchronous data acquisition instrument. The processing terminal is used to receive data from the data acquisition subsystem, calculate the dynamic fingerprint, and compare the dynamic fingerprint with the target tolerance band. The adjustable hydraulic dynamic equivalent module includes an adjustable equivalent cavity unit, an adjustable flow unit, and a replaceable equivalent inertial pipe section connected in series; the connection order of the adjustable equivalent cavity unit, the adjustable flow unit, and the replaceable equivalent inertial pipe section is not limited.

[0008] Compared with existing technologies, this invention has the following advantages and beneficial effects: By accurately replicating the characteristics of downhole drilling fluid circulation and using a modular dynamic adjustment synergistic design, it effectively solves the technical pain points of traditional workshop testing being disconnected from actual downhole working conditions and having insufficient simulation accuracy, thus improving the reliability and accuracy of workshop testing of rotary steering systems. By first determining the dynamic fingerprint and target tolerance band of the downhole circulation channel in the target well section, and clarifying that the dynamic fingerprint includes time-domain step index and frequency-domain phase index that quantify the pressure response, it achieves accurate anchoring of the dynamic characteristics of the downhole circulation channel, providing a reference benchmark that fits the actual working conditions for subsequent workshop testing. This avoids the problem of test result distortion caused by the lack of targeted working condition references in traditional testing, ensuring that the test data can truly reflect the downhole operating status. The adjustable hydraulic dynamic equivalent module connected in series in the workshop circulation test loop, through the series coordination of adjustable equivalent cavity units, adjustable flow units, and replaceable equivalent inertia pipe sections, achieves directional control of equivalent flexibility, equivalent damping, and equivalent inertia, respectively. This constructs a fully adjustable system covering the core dynamic parameters of the downhole circulation channel, breaking the limitation of traditional fixed loops that cannot adapt to the dynamic characteristics of different well sections. It can flexibly match the circulation channel characteristics of different target well sections. By applying flow disturbance excitation to the loop multiple times, combined with synchronous data acquisition from upstream flow detection devices and downstream pressure detection devices, the flow and pressure response data of the loop can be comprehensively and accurately captured, providing data support for the accurate acquisition of dynamic fingerprints. Compared with single disturbance tests, this improves the completeness and reliability of the data. Based on the acquired data, the current dynamic fingerprint is obtained and compared with the target tolerance band. By iteratively adjusting the adjustable module parameters until the indicators meet the standards, the dynamic characteristics of the workshop loop are accurately matched with the target downhole well section. This effectively avoids simulation failure problems caused by parameter deviations and significantly improves the accuracy and stability of the operating condition simulation. After finally locking the adjustable module parameters, functional tests were carried out and data was recorded. This ensured that the rotary steering system functional tests were conducted under equivalent downhole conditions, guaranteeing the validity and authority of the test results. It also provided a reusable parameter benchmark for subsequent tests of similar well sections. At the same time, the modular adjustable design also took into account the ease of operation, allowing for adaptation to different well sections without reconstructing the entire test loop. Attached Figure Description

[0009] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of a rotary guide test method for simulating downhole drilling fluid circulation in a workshop, as provided in Embodiment 1 of the present invention.

[0010] Figure 2 This is a schematic diagram of a rotary guide test system for simulating downhole drilling fluid circulation in a workshop, as provided in Embodiment 2 of the present invention.

[0011] The attached diagram shows the markings and corresponding component names: 1-Storage tank; 2-Circulation pump; 3-Bypass branch; 4-Adjustable hydraulic dynamic equivalent module; 41-Adjustable equivalent cavity unit; 42-Adjustable flow unit; 43-Replaceable equivalent inertial pipe section; 5-Measured RSS tool and its equivalent section; 6-Return pipeline; 7-Flow detection device; 8-Pressure detection device; 9-Synchronous data acquisition instrument; 10-Processing terminal. Detailed Implementation

[0012] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. The illustrative embodiments and descriptions of this invention are for illustrative purposes only and are not intended to limit the invention. The embodiments described below are some, but not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0013] In the following description, numerous specific details are set forth to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that these specific details are not necessary to practice the invention. In other embodiments, well-known structures, materials, or methods are not specifically described to avoid obscuring the invention. Unless otherwise specified, the materials, instruments, and reagents used in the following embodiments are commercially available. Unless otherwise specified, the techniques used in the embodiments are conventional methods well known to those skilled in the art.

[0014] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0015] Example 1: To address the fundamental difference in hydraulic dynamic response characteristics between existing workshop RSS test loops and the downhole circulation channel of the target well section, which makes it difficult to transfer RSS workshop test results to actual downhole operating conditions, a rotary steering test method simulating downhole drilling fluid circulation in the workshop is provided. By quantitatively characterizing the dynamic response features of the circulation channel and structurally controlling the hydraulic characteristics of the workshop loop, the dynamic response index of the workshop loop converges to the preset tolerance zone of the target well section. This provides dynamic boundary conditions consistent with downhole operating conditions for RSS functional testing, ensuring the reliability and transferability of test results.

[0016] Specifically, this embodiment provides a rotary steering test method for simulating downhole drilling fluid circulation in a workshop. Based on "dynamic fingerprint alignment," it forms a closed-loop technical route encompassing "target fingerprint definition, workshop fingerprint acquisition, parameter iterative adjustment, matching locking, and test application." Specifically: First, the dynamic fingerprint and tolerance band are extracted or calculated from the target well section, establishing a clear matching standard. Then, a workshop test loop containing an adjustable hydraulic dynamic equivalent module is constructed, and synchronous acquisition points are configured. Subsequently, the loop's dynamic characteristics are stimulated by repeatable small-amplitude flow disturbances, synchronously acquiring data and calculating the workshop dynamic fingerprint. Next, based on the deviation between the dynamic fingerprint and the target tolerance band, the equivalent module parameters are iteratively adjusted until dynamic matching is successful. Finally, the parameters are locked, and RSS testing is conducted, outputting the test results of dynamically matching the actual working conditions of the target well section.

[0017] Based on the aforementioned closed-loop technical approach, this embodiment provides a rotary steering test method for simulating downhole drilling fluid circulation in a workshop, including... Figure 1 The following steps are shown: Step 1: Determine the dynamic fingerprint and target tolerance zone of the downhole circulation channel in the target well section.

[0018] The purpose of this step is to provide a quantitative target for workshop loop matching, ensuring that there are clear judgment criteria when performing dynamic equivalent matching adjustments, and avoiding alignment between the workshop RSS test loop and the target well section based solely on a single steady-state parameter.

[0019] Specifically, a dynamic fingerprint is a set of feature instructions used to quantify the stress response of a circulating channel to flow disturbances, providing a unified benchmark for dynamic equivalent matching. This set of feature instructions includes at least two parameters: a time-domain step indicator and a frequency-domain phase indicator. The time-domain step indicator includes: rise time. T r Overshoot M p and stable time T s Frequency domain phase parameters include: phase lag at key frequencies. f ( f 2), f 2 represents the key frequency. The key frequency refers to the characteristic frequency of the pressure response in the downhole circulation channel of the target well section. f2. Determining the control bandwidth of the rotary steering system based on the main frequency of drilling pump pulsation and its low-order harmonics—First, clarify the system application scenario (e.g., rotary steering test loop); then, extract the inherent characteristics of RSS attacks and their equivalent segments. Specifically, through modal analysis or simulation calculations, obtain the main frequency of fluid pulsation of the RSS tool under rated operating pressure and flow rate (i.e., the frequency of the most intense pressure band and flow fluctuation in the pipeline, which is also the key frequency for system energy conversion and phase matching, and is used as the key frequency point). f 2. The initial baseline value.

[0020] Furthermore, the target tolerance band is the allowable fluctuation range of the dynamic fingerprint.

[0021] The dynamic fingerprint and target tolerance band are obtained as follows: The time-domain step index is extracted based on the pressure response curve after a step disturbance—rise time. T r For pressure response from P 0+0.1×Δ P Rise to P 0+0.9×Δ P The moment t 10 and t 90 The difference, i.e. T r = t 90 - t 10 ,in, P 0 represents the steady-state pressure before the disturbance, Δ P The pressure fluctuation amplitude during steady-state operation of the system; overshoot. M p The calculation formula is ,in, P peak The maximum pressure value during the pressure response process. P ss Steady-state pressure after disturbance; settling time T s For pressure response to first enter and remain at [ P ss −ε, P ss The earliest time of +ε], where ε=max(3σ,0.02×Δ P ), where σ is the standard deviation of the steady-state data before the disturbance, and the duration is... T hold ≥1 / f 2. It should be noted that the "rise time" mentioned above... T r For pressure response fromP 0+0.1×Δ P Rise to P 0+0.9×Δ P The moment t 10 and t 90 The "difference" is based on the linear characteristics of fluid dynamic response and industry standardization practices. This definition can effectively eliminate nonlinear interference, ensure the authenticity and comparability of dynamic fingerprints, and comply with the test logic of standards such as GB / T 34560-2017 "Test Methods for Dynamic Characteristics of Hydraulic Systems" and ISO 10770-2 "Test Methods for Hydraulic Valves".

[0022] The core of frequency domain phase metrics is the phase lag at key frequencies. f ( f 2) First, by analyzing the pressure signal P ( t The pressure signal is obtained by performing a Fourier transform on the flow rate signal Q(t). P ( f ) and flow signal Q ( f Then, construct the transfer function. Finally, take f ( f 2)=∠ H ( f 2). It should be noted that: f 2. Preferably select 2Hz as the filter cutoff frequency. f c =5× f 2. Repeatability threshold d rep ≤10; repeatability threshold d rep It can be adjusted according to the actual equipment.

[0023] The target tolerance band can be determined by filtering downhole effective operating condition data segments (including displacement adjustment data or pulse disturbance data) that are consistent with the well type or similar to the target well section. These effective operating condition data segments include: pre-disturbance steady-state data, response data, and post-disturbance steady-state data. The filtered effective operating condition data segments are preprocessed, including: mean processing, low-pass filtering for noise reduction, and removal of abnormal spikes. Based on each preprocessed effective operating condition data segment, the corresponding rise time is calculated. T r Overshoot M p Stable time T s Phase lag at key frequencies f ( f2) The specific values ​​of these four indicators; outliers are removed from the calculated indicators using the 3σ criterion; the distribution range of the remaining indicators is calculated as the target tolerance band (e.g., T r =0.8s-1.2s M p =5%-10%, stabilization time T s ≤3.5s f (2Hz) = 35° - 45°.

[0024] Step 1, by clarifying the various indicators and target tolerance bands of dynamic fingerprints, provides a unified benchmark for subsequent acquisition of disturbances in the workshop circuit, fingerprint calculation, and parameter adjustment, ensuring that "matching qualified" meets repeatable acceptance criteria.

[0025] Step 2: Construct a workshop circulation test loop containing an adjustable hydraulic dynamic equivalent module. Arrange a flow detection device in the upstream main channel of the adjustable hydraulic dynamic equivalent module and a pressure detection device in the downstream main channel of the adjustable hydraulic dynamic equivalent module.

[0026] The purpose of this step is to build a workshop testing hardware environment with dynamic characteristic control capabilities, realize independent control of loop energy storage, dissipation, and inertial characteristics through modular design, and ensure the accuracy and synchronization of data acquisition through standardized measurement point layout, so as to provide reliable hardware support for dynamic fingerprint extraction.

[0027] Specifically: First, a workshop circulation test loop including an adjustable hydraulic dynamic equivalent module is constructed—the storage tank, circulation pump, bypass branch, adjustable hydraulic dynamic equivalent module, the tested RSS tool and its equivalent section, and return pipeline are connected in series according to the drilling fluid flow direction to form a closed loop. The storage tank has a volume ≥ 5m³, is equipped with a level gauge and vent, and the drilling fluid inside the storage tank needs to be degassed and filtered. The circulation pump is preferably a frequency converter-driven pump, with a rated flow rate ≥ 1.2 times the maximum test flow rate and a rated pressure ≥ 1.5 times the maximum test pressure. A check valve is installed at the outlet of the circulation pump. The bypass branch consists of a fast-response valve with a response time ≤ 100ms and a return pipe. The diameter of the return pipeline needs to match the main body of the loop to reduce local resistance structures. It should be noted that: (1) The volume of the storage tank is set to ≥5m³, which can be calculated and determined based on the maximum test circulation flow rate, the duration of a single test, and the safety buffer volume requirements; (2) According to the safety redundancy design principle (such as the "Safety Specification for Petroleum Drilling Engineering"), the storage tank is equipped with a level gauge and an exhaust port, and the drilling fluid in the tank needs to be degassed and filtered to a gas content ≤0.5% and a solid particle size ≤5μm; (3) According to the system safety operation requirements (such as the "Technical Specification for Centrifugal Pump Selection"), the circulation pump is preferably driven by a variable frequency drive. Type, its rated flow rate ≥ 1.2 times the maximum test flow rate (reserving redundancy for pipeline resistance changes), rated pressure ≥ 1.5 times the maximum test pressure (adapting to instantaneous pressure peak conditions), and a check valve is installed at the outlet of the circulating pump; (4) the bypass branch is composed of a fast response valve with a response time ≤ 100ms and a return tank pipe (to meet the synchronization requirements of dynamic operating condition control); (5) the diameter of the return pipeline is matched with the main body of the loop, and a structure such as a large curvature radius elbow and a smooth reducing joint is adopted to reduce local resistance and reduce friction loss. Furthermore, the adjustable hydraulic dynamic equivalent module includes: an adjustable equivalent cavity unit, an adjustable flow unit, and a replaceable equivalent inertial pipe section. Among them: (1) The adjustable equivalent cavity unit preferably uses a diaphragm type or airbag type accumulator, and is equipped with a replaceable modular cavity. Based on the standardized cavity mold specifications (such as 0.5L, 1L, 2L, 4L, 5L, etc.) and the positive correlation between the flexibility C of the equivalent cavity and the volume V, C=V / E (E is the elastic modulus of the medium), the volume range that matches the natural frequency of the system can be selected from the standardized cavity mold specifications through comparative experiments. For example, through comparative experiments, it was found that the energy conversion efficiency of the system is ≥85% under the volume range of 1L-4L, while the flexibility is too small when it is below 1L, resulting in large pressure fluctuations, and the volume is redundant and the response is lagging when it is above 4L. Therefore, the three optimal ranges of 1L, 2L, and 4L were selected. (2) The adjustable equivalent cavity unit is equipped with a pre-charge valve. According to the industry-standard design guidelines for hydraulic accumulator applications (such as the recommended range of pre-charge pressure for diaphragm accumulators in ISO 14383 "Hydraulic Transmission - Accumulators - Specification") and the system working pressure of RSS, the pressure multiple range of the pre-charge pressure is set through experimental verification. For example, experimental verification shows that the pressure stability of RSS is optimal at a pre-charge pressure of 0.6-0.8 times the working pressure of RSS. When the pre-charge pressure is too low (such as <0.6 times the working pressure of RSS), the diaphragm and air bladder are easily compressed to the limit position by the medium, losing their flexibility adjustment function. When the pre-charge pressure is too high (such as >0.8 times the working pressure of RSS), the compressible space of the cavity is too small, and it cannot effectively absorb system pressure fluctuations. Therefore, 0.6-0.8 times the working pressure of RSS is selected as the pre-charge pressure. (3) The adjustable flow unit adopts a precision throttle valve with a dial and a locking nut. The equivalent damping R is adjusted by changing the opening of the precision throttle valve. The adjustment step of the precision throttle valve needs to be matched with the radial direction of the throttle orifice. The fine control of damping can be achieved by adjusting the small step of the precision throttle valve to meet the industry design standards of precision throttle valves (such as GB / T8106 "Throttle Valve"). For example, it has been verified by experiments that under certain working conditions, the change in orifice diameter is about 0.1 mm for every 1 / 8 turn of the needle valve, and the change in damping value is ≤5%, which can meet the accuracy requirements of the system for damping adjustment and meet the industry design standards of precision throttle valves. (4) The replaceable equivalent inertia pipe section is configured as a set of steel pipe sections that can be quickly disassembled and assembled. The pipe section ends are equipped with positioning structures and specification markings to prevent misalignment during installation. By replacing pipe sections of different lengths and / or inner diameter specifications, the equivalent inertia of the circuit can be flexibly adjusted, thereby accurately adjusting the phase lag and response speed characteristics of the pressure response. The pipe length range can be determined according to the phase lag control target. For example, experimental verification or theoretical calculations show that, under a phase lag target of 0-120°, a pipe length range of 0.5-3m can meet the phase matching requirements under different operating conditions. The pipe inner diameter range can be determined through fluid simulation (such as CFD simulation).For example, fluid simulations have shown that an inner diameter of 50-80mm can achieve the optimal match between inertia and damping while ensuring flow rate.

[0028] Then, a flow detection device is installed in the upstream main channel of the adjustable hydraulic dynamic equivalent module. The flow detection device is an electromagnetic or ultrasonic flow meter with an accuracy of ≥0.5 and a response time of ≤10ms. The flow meter is installed in the upstream straight pipe section of the adjustable hydraulic dynamic equivalent module.

[0029] Finally, a pressure detection device is installed in the downstream main channel of the adjustable hydraulic dynamic equivalent module—the pressure detection device is selected from pressure sensors with an accuracy ≥0.2 and a response frequency ≥100Hz; the first pressure measuring point P 1. A straight pipe section downstream of the adjustable hydraulic dynamic equivalent module and before the RSS inlet (located at a distance ≥ 3 times the pipe diameter from the outlet of the adjustable hydraulic dynamic equivalent module), the second measuring point. P 2. The third measuring point is located between the outlet of the circulating pump and the inlet of the adjustable hydraulic dynamic equivalent module. P 3. Installed on the RSS outlet or return line. At each first pressure measurement... P 1. Each second pressure measuring point P 2 and each third pressure measuring point P Pressure sensors were installed at three locations.

[0030] After constructing the workshop cycle test loop and installing the flow detection device and pressure detection device, a unified clock-triggered (synchronization error ≤1ms) synchronous data acquisition instrument is used to collect data from the flow detection device and pressure detection device. The data storage format is .csv or .dat.

[0031] Step 2, by constructing a workshop loop test circuit and designing an adjustable hydraulic dynamic equivalent module, enables precise control of the dynamic characteristics of the workshop loop. In addition, by standardizing the arrangement of flow and pressure measurement points, the synchronization and accuracy of pressure and flow response data are ensured, providing a reliable hardware foundation for subsequent perturbation, data collection, and dynamic fingerprint calculation.

[0032] Step 3: Repeatedly apply flow disturbance excitation to the fluid in the workshop circulation test loop, and simultaneously collect the flow response data and pressure response data of the workshop circulation test loop.

[0033] The purpose of this step is to stimulate the dynamic characteristics of the workshop cycle test loop with a controllable and reproducible flow disturbance excitation, so that the workshop cycle test loop can fully and dynamically respond to the flow disturbance excitation, and ensure that comparable dynamic fingerprints can be stably extracted from the collected flow response data and pressure response data, so as to provide effective data support for subsequent fingerprint comparison and adjustment parameters.

[0034] Specifically: This embodiment provides two disturbance methods adapted to different pump types—for variable frequency pumps, a speed step disturbance is preferred, with the pump's reference speed set to [value missing]. n 0 (corresponding to the baseline flow rate) Q 0), adjust the pump speed stepwise to n 0×(1+α), where α is the relative proportionality coefficient of the flow disturbance amplitude, which can be taken as α=1. Set the duration of the step disturbance state (this duration needs to cover the stabilization time in the target tolerance band). T s The upper limit ensures complete capture of the entire process of pressure response rise, overshoot, and steady state, such as the duration of step disturbances. T =2s~5s), then the flow rate is restored to the baseline flow rate. Q 0; For non-frequency pumps, a step disturbance of the bypass valve opening is used to maintain a constant pump speed, and a flow step is generated by rapidly adjusting the bypass valve opening.

[0035] Furthermore, the amplitude of the flow disturbance excitation is 1%-5% of the reference flow rate. This disturbance amplitude range can be determined through experimental verification to meet the limit requirements for steady-state fluctuations in fluid systems in GB / T3766 "General Rules and Safety Requirements for Hydraulic Transmission Systems and Their Components". On the one hand, when the disturbance amplitude is less than 1% of the reference flow rate, the intensity of the disturbance signal is weaker than the system's own pressure fluctuation noise (such as the inherent fluid pulsation noise of hydraulic / pneumatic systems, which is usually 0.5%-0.8% of the reference flow rate). At this time, the disturbance signal will be covered by noise, and the system's control module cannot accurately identify the disturbance input, resulting in the failure of control of key indicators such as phase lag and energy conversion efficiency. On the other hand, when the disturbance amplitude exceeds 5% of the reference flow rate, the system will enter the non-steady-state operating range, the turbulence effect of the fluid will be enhanced, and the deviation between the theoretical calculation model of equivalent compliance and damping and the actual working condition will exceed 15%, resulting in the inability to accurately achieve the preset phase control target (such as lag of 60°-90°), and problems such as pressure shock and excessive flow fluctuation will occur.

[0036] Furthermore, the perturbation is repeated multiple times at each operating point (at least 3 times), with a time interval between two perturbations (e.g., ≥20 seconds). Before perturbing, the pump must be kept at the reference flow rate. Q Preset steady-state operation duration at 0 (e.g., ≥10 seconds); record the disturbance method and baseline flow rate. Q 0, relative proportionality coefficient α, duration of step disturbance state T Parameters such as the number of repetitions.

[0037] After the disturbance begins, the drive synchronous data acquisition instrument synchronously acquires data at the first pressure measurement point. P 1. Second pressure measuring point P 2 and the third pressure measuring pointP The pressure response data and the flow response data collected by the synchronous data acquisition instrument should be collected for a duration that covers the entire disturbance process before, during, and after the disturbance to ensure data integrity. For example, the collection duration should cover 10 seconds before the disturbance, 5 seconds during the response, and 10 seconds after the disturbance.

[0038] Step 3 involves repeatedly applying flow disturbances to the fluid in the workshop circulation test loop, thereby fully stimulating the dynamic characteristics of the workshop circulation test loop without changing the steady-state operating point of the system. By simultaneously collecting pressure response data and flow response data, the original basis for subsequent calculation of dynamic fingerprints is provided, and the repeated disturbances ensure the reliability and repeatability of the data, laying the foundation for statistical calculation and repeatability determination of dynamic fingerprints in subsequent steps.

[0039] Step 4: Based on the flow response data and pressure response data, obtain the current dynamic fingerprint of the workshop cyclic test loop through data preprocessing, calculation of time domain step index and calculation of frequency domain phase index.

[0040] The purpose of this step is to transform the raw pressure response data and flow response data into quantifiable and comparable dynamic fingerprint indicators, thereby achieving accurate characterization of the dynamic characteristics of the workshop circuit and providing direct quantitative basis for comparison with the target tolerance band.

[0041] Specifically: Data preprocessing is performed on the flow response and pressure response data. Effective data segments corresponding to each flow disturbance are extracted from the raw flow response and pressure response data. These effective data segments must completely include the steady-state segment before the disturbance (duration ≥ 10 seconds, ensuring reliable steady-state mean calculation), the disturbance response segment (duration ≥ 5 seconds, fully capturing the dynamic response process of the workshop cycle test loop to pressure and flow), and the steady-state segment after the disturbance (duration ≥ 10 seconds, confirming system recovery to steady state). Subsequently, the amplitude of the collected data (flow response and pressure response data) is corrected using pre-calibrated calibration coefficients obtained from the sensors (flowmeter and pressure sensor). The pressure sensor calibration coefficients are obtained using a standard pressure source. K p The corrected pressure data is P cal , P cal = P raw × K p , P raw This represents the raw pressure response data collected, and the correction factor for the flow meter calibrated using the constant volume time method (standard measuring cylinder + high-precision timer). K qThe corrected traffic data is Q cal , Q cal = Q raw × K q , Q raw This represents the raw flow response data collected, ensuring the absolute accuracy of the pressure response data and flow response data, and providing a reliable foundation for subsequent dynamic fingerprint index calculations.

[0042] Based on the preprocessed flow response and pressure response data, the time-domain step index is calculated—first, the pressure change Δ is calculated. P Pressure change Δ P Corrected pressure data for the steady-state period after disturbance P cal,post average mean ( P cal,post Subtract the corrected pressure data for the steady-state period before the disturbance. P cal,pre average mean ( P cal,pre ), that is, Δ P = mean ( P cal,post )- mean ( P cal,pre Then, the pressure response data after removing the mean; P In the curve of 2', the first value reaching 0.1×Δ is extracted. P corresponding time t 10 , compared to the first time reaching 0.9×Δ P corresponding time t 90 (If there are slight oscillations in the response, the moment when the corresponding proportion is first reached is taken to ensure consistency of the definition.) The difference between the two is the rise time. Tᵣ ,Right now Tᵣ = t 90 - t 10 Subsequently, from the mean-removed pressure response data... P Extract the maximum peak value from the 2' response curve. P peak The actual peak pressure is obtained by combining the corrected average pressure value of the steady-state period before the disturbance. P peak = P peak '+ mean ( P cal,pre According to the formula M p =( P peak - P ss ) / Δ P Calculate overshoot by multiplying by 100%. M p (in P ss = mean ( P cal,post If the response has no overshoot, then... P peak ≤ P ss ,but M p =0%); Finally, starting from the moment the step disturbance occurs, the search correction pressure data first enters and remains at [ P ss -ε, P ss The earliest time within the range of +ε] is the settling time. T s Where ε is the allowable error for steady-state determination, taken as max(3σ, 0.02×Δ). P ), where σ is the standard deviation of the steady-state data before the disturbance, and the duration is... T hold Not less than the key frequency f 2 corresponds to period 1 / f 2. Avoid misjudging a brief period of entry into the allowable range as stable.

[0043] Based on the preprocessed flow response and pressure response data, the frequency domain phase index is calculated—first, the preprocessed pressure deviation is analyzed. P 2′ (i.e.) P cal - mean ( P cal,pre )) and flow deviation Q '(Right now Q cal - mean ( Q cal,preEnhanced data preprocessing (including: standardizing data length, regularizing data points, removing trend terms, removing and repairing outliers, and strengthening anti-aliasing filtering) ensures that the two data segments have completely consistent time lengths (both covering the effective data segments of 10s before the disturbance, 5s of response, and 10s after the disturbance), and that the number of data points is an integer power of 2 (e.g., 2048 points, 4096 points) to improve the frequency domain resolution and calculation accuracy of the Fourier transform. Subsequently, Hanning windows are applied to both data segments to suppress spectral leakage. The Hanning window weighting coefficients are calculated using the following formula: w ( n ) = 0.5 − 0.5 × cos(2 πn / ( N -1)), where n =0,1,..., N -1, N The number of signal data points; based on the windowed flow response data and pressure response data, the frequency domain signal of the pressure is calculated using Fast Fourier Transform. P ( f Frequency domain signal of flow rate Q ( f The frequency domain range covers from 0 to half the sampling frequency (Nyquist frequency); next, the frequency domain transfer function is constructed. (That is, the ratio of the amplitude of the pressure frequency domain signal to the amplitude of the flow frequency domain signal at the same frequency point, and the phase is the difference between the phase of the pressure frequency domain signal and the phase of the flow frequency domain signal); for preset key frequency points f 2 (2Hz is preferred, but can be adjusted according to the dynamic characteristics of the target well section), extract the transfer function. H ( f The phase angle corresponding to this frequency point f ( f 2) The phase angle is in degrees (°), and its range is [−180°, 180°]; if the frequency point is near (e.g. f If the phase data within the range of 2 ± 0.1 Hz exhibits significant fluctuations (e.g., dispersion ≥ 5°), then... f Within a bandwidth of 2±0.2Hz, a moving average method (the width of the moving window can be set to 3 adjacent frequency points) is used for phase smoothing. After smoothing, the phase value corresponding to the center frequency of the window is taken as the final value. f ( f 2) Ensure the stability and reliability of the phase index.

[0044] Statistical dynamic fingerprint results—Calculate the mean and standard deviation of the indicators (time domain step index and frequency domain phase preparation) for multiple (≥3) repeated perturbations. Use the mean as the current dynamic fingerprint and the standard deviation for repeatability determination.

[0045] Step 4 transforms the raw response data into a unified dynamic fingerprint index through a standardized data processing and index calculation process. This enables the quantitative characterization of the dynamic characteristics of the workshop cyclic test loop. The output results are directly used for subsequent comparison with the target tolerance band, providing a clear basis for deviation for iterative adjustment. This establishes the correlation between "data acquisition, fingerprint extraction, and comparative adjustment".

[0046] Step 5: Compare the current dynamic fingerprint of the workshop cycle test loop with the target tolerance band. If the current dynamic fingerprint does not fall into the tolerance band, adjust the parameters of the adjustable equivalent cavity unit, the adjustable flow unit and the replaceable equivalent inertial tube section iteratively according to the deviation results until the dynamic fingerprint index falls into the target tolerance band.

[0047] The purpose of this step is to improve matching efficiency and accuracy by using closed-loop iteration to achieve convergence of the dynamic characteristics of the workshop cyclic test loop towards the target well section, based on fingerprint deviation and physical laws.

[0048] Specifically: First, set the initial parameters of the adjustable hydraulic dynamic equivalent module—(1) at the reference flow rate. Q 0 and Q 0+ δQ ( δQ =1%× Q 0~3%× Q 0) The steady-state pressure was measured under these two operating conditions. P ss1 and steady-state pressure P ss2 Then the initial equivalent damping R 0≈( P ss2 - P ss1 ) / δQ , the unit is MPa / (L / s); (2) the volume range selection of the adjustable equivalent cavity unit is "maximum volume range ÷ 2" (e.g. 2L), the pre-charge pressure is 0.6-0.8 times the steady-state RSS working pressure; (3) the replaceable inertial pipe section is selected with a length of "longest pipe length ÷ 2" and an inner diameter of "maximum pipe diameter ÷ 2", the target phase lags. f ( f 2) When the tolerance is less than 50% of the lower limit of the target tolerance zone, a pipe section with a length of ≥2m shall be selected.

[0049] Then, by gradually adjusting the parameters of the adjustable hydraulic dynamic equivalent module, the dynamic fingerprint of the workshop loop is brought to converge within the target tolerance band—while monitoring the overshoot in real time during system operation. M p Ascent time T rCharacteristic frequencies f Phase lag at 2 f ( f 2) Adjusting the time T s And core performance indicators such as steady-state voltage drop, and perform corresponding parameter adjustment operations for deviations of each indicator. Specifically: (1) When the overshoot is M p When the target upper limit is exceeded, the equivalent damping is increased. R Specifically, the precision needle valve can be closed by 1 / 8 turn or the orifice plate assembly with a smaller orifice diameter can be replaced. If the standard is still not met after adjustment, the equivalent compliance can be further increased. C (2) When overshoot M p When the effective damping is below the target lower limit, reduce the equivalent damping. R That is, open the precision needle valve by 1 / 8 turn; when the rise time T r When the target upper limit is exceeded, the equivalent compliance C is reduced, which can be achieved by increasing the pre-charge pressure by 0.2 MPa or replacing it with a smaller volume cavity module; (3) When the rise time T r When the pressure is below the target lower limit, increase the equivalent flexibility C. Specifically, this can be achieved by reducing the pre-charge pressure by 0.2 MPa or replacing the module with one of a larger volumetric cavity. Alternatively, the length of the inertial tube section can be directly increased. L (4) When the characteristic frequency f Phase lag at 2 f ( f 2) When the value is below the target lower limit, increase the length of the inertial tube section. L That is, replacing the pipe section assembly with a longer or larger inner diameter; (5) when the phase lags f ( f 2) When the target upper limit is exceeded, reduce the length of the inertial tube segment. L That is, replacing the pipe section assembly with a shorter or smaller inner diameter; (6) when adjusting time T s When the target upper limit is exceeded, the equivalent damping is increased. R (7) When the steady-state voltage drop of the system deviates from the target value, first adjust the equivalent damping. R Simultaneously adjust the pump's reference speed to achieve the reference flow rate. Q The parameters are adjusted iteratively from 0 to the target value range to complete the entire process and ensure that all system performance indicators remain stable within the target range.

[0050] Step 5, through a directional adjustment and closed-loop iterative process based on physical laws, reduces the number of blind experiments and achieves rapid convergence of the workshop dynamic fingerprint to the target tolerance band, forming an acceptable "dynamic equivalent state." This step provides a stable operating condition that meets the dynamic equivalence requirements for subsequent parameter locking and RSS testing.

[0051] Step 6: Lock all adjustment parameters of the adjustable hydraulic dynamic equivalent module, perform functional tests on the rotary guide system under all locked adjustment parameters, and record the test data and module lock parameters.

[0052] The purpose of this step is to solidify the dynamic equivalent state, prevent parameter drift during the test, ensure that the RSS test is carried out under boundary conditions consistent with the dynamic response of the downhole working conditions, and guarantee the transferability and traceability of the test conclusions.

[0053] Specifically: First, lock all adjustment parameters of the adjustable hydraulic dynamic equivalent module. In the adjustable flow unit, the needle valve is fixed with a lock nut and marked with paint. The adjustable equivalent cavity unit records the volume setting and pre-charge pressure. The pre-charge valve is capped with a protective cap and the locking parameters are marked. The replaceable equivalent inertia pipe section is fixed with a positioning pin and affixed with a specification label.

[0054] Then, functional tests of the rotary guide system were conducted with all adjustment parameters locked—the baseline flow rate was maintained during the tests. Q 0 is consistent with the matching. When switching workflows, it is necessary to re-verify whether the dynamic fingerprint is within the tolerance band, and readjust if necessary; real-time monitoring of the first pressure measurement point. P 1. Second pressure measuring point P 2 and the third pressure measuring point P 3. Pressure response data and flow signal; pause troubleshooting if abnormal fluctuations occur. Record test data such as guide force, tool speed, and valve control signal, and simultaneously record the locking parameters of the adjustable hydraulic dynamic equivalent module.

[0055] Step 6 ensures the stability of the dynamic equivalent state through parameter locking, enabling the RSS test to be conducted in an environment consistent with the downhole dynamic response, fundamentally solving the problem of non-transferability of test conclusions. Simultaneously, data recording provides a basis for subsequent traceability, forming a complete closed loop of "matching, testing, and traceability."

[0056] Step 7: Output a dynamic equivalent confirmation record containing the target fingerprint tolerance band, workshop loop parameters, final configuration of the equivalent module, dynamic fingerprint calculation results, iterative adjustment records, and qualification judgment conclusions.

[0057] The purpose of this step is to achieve comprehensive traceability of the dynamic equivalent matching process and results, establish a unique correspondence between RSS test data and dynamic equivalent states, and improve the credibility and engineering acceptance of test conclusions.

[0058] Specifically: The dynamic equivalent confirmation record should include at least: (1) Target well section information, such as well type, well depth, drill string specifications, drilling fluid parameters, etc.

[0059] (2) Target fingerprint tolerance band, including rise time T r Overshoot M p Stable time T s Key frequency phase lag f ( f 2) Target scope and determination basis (such as historical data extraction and physical parameter estimation).

[0060] (3) Workshop circuit parameters, such as liquid storage tank volume, circulating pump model and parameters, circuit pipe diameter, and reference flow rate. Q 0. Drilling fluid parameters (density, viscosity), etc.

[0061] (4) Final configuration of adjustable hydraulic dynamic equivalent module, such as the volume level and pre-charge pressure of the cavity unit, the type and opening of the throttling unit, the number, length and inner diameter of the inertial pipe section.

[0062] (5) Sensor calibration records, such as sensor model, calibration date, standard instrument number, calibration coefficient and correction coefficient.

[0063] (6) Dynamic fingerprint test data, such as the original data storage path of three repeated perturbations, the preprocessed pressure-flow curve, and the average and standard deviation of dynamic fingerprint indicators.

[0064] (7) Iterative adjustment records, such as the adjustment object, adjustment action, fingerprint index before adjustment, fingerprint index after adjustment, and judgment result for each iteration.

[0065] (8) Qualification judgment conclusion, used to clarify whether the core criterion, repeatability criterion and steady-state pressure drop criterion are met.

[0066] In summary, the rotary steering test method for simulating downhole drilling fluid circulation in the workshop provided in this embodiment forms a quantifiable, repeatable, and traceable technical means by executing a closed-loop technical route of "target fingerprint definition, workshop fingerprint acquisition, parameter iterative adjustment, matching and locking, and test application", thereby achieving precise alignment of the workshop loop and the downhole channel of the target well section in terms of dynamic response characteristics.

[0067] Example 2: A rotary steering test system for simulating downhole drilling fluid circulation in a workshop is provided to implement the rotary steering test method described in Example 1. Figure 2 As shown, the rotary guide testing system includes: Fluid circulation subsystem: The following components are connected in sequence: storage tank 1, circulation pump 2, bypass branch 3, adjustable hydraulic dynamic equivalent module 4, measured RSS tool and its equivalent section 5, and return pipeline 6.

[0068] The data acquisition subsystem includes a flow detection device 7 installed in the upstream main channel of the adjustable hydraulic dynamic equivalent module 4, a pressure detection device 8 installed in the downstream main channel of the adjustable hydraulic dynamic equivalent module 4, and a synchronous data acquisition instrument 9. The synchronous acquisition instrument can use hardware synchronization or a unified clock triggering method to ensure that the pressure and flow signals have a consistent time reference in the time domain and frequency domain calculations. The adjustable hydraulic dynamic equivalent module 4 includes an adjustable equivalent cavity unit 41, an adjustable flow control unit 42, and a replaceable equivalent inertial pipe section 43.

[0069] Processing terminal 10: Processing terminal 10 can be an industrial control computer, a host computer, or an embedded computing unit, configured to receive pressure and flow data from the data acquisition subsystem, perform data preprocessing, dynamic fingerprint calculation, compare the dynamic fingerprint with the target tolerance band, and output parameter adjustment suggestions.

[0070] The adjustable hydraulic dynamic equivalent module 4 includes: an adjustable equivalent cavity unit 41, an adjustable flow unit 42, and a replaceable equivalent inertia tube section 43 connected in series, and the connection order of the three is not limited. The adjustable equivalent cavity unit 41 can adopt a diaphragm type or air bladder type accumulator and be equipped with a pre-charge pressure regulating valve and a modular cavity; the adjustable flow unit 42 can adopt a precision needle valve with a dial and locking device or a replaceable orifice plate assembly; the replaceable equivalent inertia tube section 43 can adopt a set of quick-disassembly and disassembly steel pipes with different geometric specifications, and positioning structures or markings are set at both ends to prevent incorrect installation.

[0071] It should be understood that the terms "system," "device," "unit," and / or "module" as used in this specification are a method of distinguishing different components, elements, parts, sections, or assemblies at different levels. However, if other terms can achieve the same purpose, they may be replaced by other expressions.

[0072] As indicated in this specification and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of expressly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0073] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0074] It should be noted that the structures, proportions, sizes, etc., illustrated in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and are not intended to limit the scope of the invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the disclosed technical content. Furthermore, terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

Claims

1. A rotary steering test method for simulating downhole drilling fluid circulation in a workshop, characterized in that, Includes the following steps: Determine the dynamic fingerprint and target tolerance band of the downhole circulation channel in the target well section; wherein, the dynamic fingerprint includes a set of characteristic commands used to quantitatively characterize the pressure response of the circulation channel to flow disturbances; the set of characteristic commands includes time-domain step index and frequency-domain phase index; A workshop circulation test loop is constructed; an adjustable hydraulic dynamic equivalent module is connected in series in the workshop circulation test loop; a flow detection device is arranged in the upstream main channel of the adjustable hydraulic dynamic equivalent module, and a pressure detection device is arranged in the downstream main channel of the adjustable hydraulic dynamic equivalent module; the adjustable hydraulic dynamic equivalent module includes an adjustable equivalent cavity unit, an adjustable flow unit, and a replaceable equivalent inertia pipe section connected in series; the adjustable equivalent cavity unit is used to adjust the equivalent flexibility of the workshop circulation test loop, the adjustable flow unit is used to adjust the equivalent damping of the workshop circulation test loop, and the replaceable equivalent inertia pipe section is used to adjust the equivalent inertia of the workshop circulation test loop; The flow perturbation excitation in the fluid in the workshop circulation test loop is repeatedly applied, and the flow response data of the workshop circulation test loop is collected using a flow detection device and the pressure response data of the workshop circulation test loop is collected using a pressure detection device. Based on the collected flow response data and pressure response data, the current dynamic fingerprint of the workshop cyclic test loop is obtained; Compare the current dynamic fingerprint of the workshop cycle test loop with the target tolerance band. If the current dynamic fingerprint does not fall into the tolerance band, adjust the parameters of the adjustable equivalent cavity unit, the adjustable flow unit and the replaceable equivalent inertial tube section iteratively according to the deviation results until the dynamic fingerprint indicators all fall into the target tolerance band. Lock all adjustment parameters of the adjustable hydraulic dynamic equivalent module, perform functional tests on the rotary guide system under all locked adjustment parameters, and record the test data and module locking parameters.

2. The rotary steering test method for simulating downhole drilling fluid circulation in a workshop according to claim 1, characterized in that, The time-domain step metric for dynamic fingerprints includes: rise time. T r Overshoot M p and stable time T s At least one of the following; frequency domain phase parameters include: phase lag at key frequencies. φ ( f 2); f 2 represents the key frequency point, which refers to the characteristic frequency of the pressure response in the downhole circulation channel of the target well section; Let Δ P steady-state pressure before disturbance P 0 and steady-state pressure after disturbance P ss The change in pressure between; P peak This represents the maximum pressure value during the pressure response process. Ascent Time T r For pressure response self P 0 rises to P 0+0.1×Δ P The moment t 10 and rise to P 0+0.9×Δ P The moment t 90 The time difference between them; Overshoot M p The calculation formula is: ;in, P peak This represents the maximum pressure value during the pressure response process. P ss The steady-state pressure after the disturbance; Δ P steady-state pressure before disturbance P 0 and steady-state pressure after disturbance P ss The change in pressure between; Stabilization time T s For pressure response to first enter and remain at [ P ss −ε, P ss The earliest time within the range of +ε]; where ε is the allowable error for stability determination, ε=max(3σ,0.02×Δ P ), where σ is the standard deviation of the steady-state data before the disturbance; hold time T hold Not less than the key frequency f 2 corresponds to period 1 / f 2; Key frequency phase lag φ ( f 2) For key frequency points f At point 2, the phase angle of the frequency domain transfer function of the pressure signal relative to the flow signal.

3. The rotary steering test method for simulating downhole drilling fluid circulation in a workshop according to claim 1, characterized in that, The adjustment methods of the adjustable hydraulic dynamic equivalent module specifically include: The equivalent flexibility of the circuit can be adjusted by changing the effective gas chamber volume or the gas pre-charge pressure of the adjustable equivalent cavity unit. The equivalent damping of the circuit is adjusted by changing the valve opening of the adjustable flow unit. The equivalent inertia of the loop can be adjusted by replacing pipe sections with different lengths or inner diameters as replaceable equivalent inertia pipe sections.

4. The rotary steering test method for simulating downhole drilling fluid circulation in a workshop according to claim 1, characterized in that, Iterative adjustment of the parameters of the adjustable equivalent cavity unit, the adjustable flow unit, and the replaceable equivalent inertial tube section includes the following steps: When the overshoot of the workshop cycle test loop M p When the target tolerance band limit is exceeded, the equivalent damping of the adjustable flow unit is increased; When the rise time of the workshop cycle test loop T r When the target tolerance band limit is exceeded, reduce the equivalent flexibility of the adjustable equivalent cavity unit and / or reduce the equivalent inertia of the replaceable equivalent inertia section; When the key frequency point phase lag of the workshop cycle test loop φ ( f 2) When the value is below the lower limit of the target tolerance band, increase the equivalent inertia of the replaceable equivalent inertia tube section and / or increase the equivalent flexibility of the adjustable equivalent cavity unit.

5. The rotary steering test method for simulating downhole drilling fluid circulation in a workshop according to claim 1, characterized in that, Repeatedly applying flow disturbance stimuli includes the following steps: Control the speed of the circulating pump to produce a step change, or keep the speed of the circulating pump constant and quickly adjust the opening of the bypass branch valve; The magnitude of the flow disturbance excitation is controlled between 1% and 5% of the baseline flow. The hold time after the disturbance is not less than the preset minimum hold time; the minimum hold time covers the settling time within the target tolerance band. T s The upper limit.

6. The rotary steering test method for simulating downhole drilling fluid circulation in a workshop according to claim 1, characterized in that, The method for determining the dynamic fingerprint and target tolerance zone of the downhole circulation channel in the target well section is as follows: extract historical downhole drilling data with the same well type or similar RSS as the target well section, screen out the working condition segments containing displacement adjustment or pulse disturbance, and extract the dynamic fingerprint statistical distribution as the target tolerance zone through data processing.

7. A rotary steering test method for simulating downhole drilling fluid circulation in a workshop according to claim 2 or 5, characterized in that, Determine key frequency points f Method 2 is determined based on the main frequency of the drilling pump pulsation and its low-order harmonic control bandwidth.

8. The rotary steering test method for simulating downhole drilling fluid circulation in a workshop according to claim 1, characterized in that, Before obtaining the current dynamic fingerprint of the workshop cyclic test loop, the following steps are also included: The collected raw pressure response data and flow response data are processed to remove the mean; A low-pass filter is used to denoise the mean-processed pressure and flow response data; the cutoff frequency of the low-pass filter is the target key frequency. f 2 is 3 to 10 times that of 2.

9. The rotary steering test method for simulating downhole drilling fluid circulation in a workshop according to claim 1, characterized in that, After locking all adjustment parameters of the adjustable hydraulic dynamic equivalent module, the following steps are also included: Output dynamic equivalent confirmation record; the dynamic equivalent confirmation record includes: target tolerance band, configuration parameters of the locked equivalent module, dynamic fingerprint index value for comparison, and qualification judgment conclusion.

10. A rotary steering test system for simulating downhole drilling fluid circulation in a workshop, characterized in that, Used to perform the rotary guide test method as described in any one of claims 1-9; The rotary guide testing system includes: The fluid circulation subsystem includes a storage tank (1), a circulation pump (2), an adjustable hydraulic dynamic equivalent module (4), an RSS tool and its equivalent section (5), and a return pipeline (6) connected in sequence. The data acquisition subsystem includes a flow detection device (7) installed in the upstream main channel of the adjustable hydraulic dynamic equivalent module (4), a pressure detection device (8) installed in the downstream main channel of the adjustable hydraulic dynamic equivalent module (4), and a synchronous data acquisition instrument (9). The processing terminal is used to receive data from the data acquisition subsystem, calculate the dynamic fingerprint, and compare the dynamic fingerprint with the target tolerance band. The adjustable hydraulic dynamic equivalent module (4) includes an adjustable equivalent cavity unit (41), an adjustable flow unit (42), and a replaceable equivalent inertial pipe section (43) connected in series; the connection order of the adjustable equivalent cavity unit (41), the adjustable flow unit (42), and the replaceable equivalent inertial pipe section (43) is not limited.

11. The rotary steering test system for simulating downhole drilling fluid circulation in a workshop according to claim 10, characterized in that, The adjustable equivalent cavity unit (41) includes: a diaphragm accumulator or a bladder accumulator; the adjustable equivalent cavity unit (41) is equipped with an inflation valve for adjusting the pre-charge pressure, and the chamber of the adjustable equivalent cavity unit (41) is a replaceable modular structure.

12. The rotary steering test system for simulating downhole drilling fluid circulation in a workshop according to claim 10, characterized in that, The adjustable flow unit (42) includes a precision needle valve with an opening scale and a locking device.

13. The rotary steering test system for simulating downhole drilling fluid circulation in a workshop according to claim 10, characterized in that, The replaceable equivalent inertia tube section (43) includes a set of quick-release steel tubes with various lengths and / or various inner diameters; both ends of the quick-release steel tubes are provided with positioning structures or markings to prevent misinstallation.

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