Self-adaptive hole drift angle control method based on stratum response real-time identification

Abstract

The invention relates to the field of directional drilling hole drift angle control, in particular to a self-adaptive hole drift angle closed-loop control method based on stratum response real-time identification. According to the method, after hole drift angle measurement data obtained after filtering processing in a preset control period and applied guiding force data are obtained in real time, a real-time deflecting capacity coefficient for quantifying current stratum response characteristics is calculated, and an expected deflecting rate given by an upper layer trajectory planning module is combined; and a self-adaptive feedforward control law is adopted to reversely calculate the guiding force needing to be applied in the next control period, and closed-loop control is formed until the hole drift angle reaches a target value. According to the method, the problems of low well track control precision and poor stability caused by factors such as stratum uncertainty, measurement noise and tool response errors in the prior art are well solved, accurate, stable and automatic control over the well oblique angle is achieved, and the well drilling efficiency and quality are improved.

Description

Technical Field

[0001] This invention relates to the field of well inclination angle control in directional drilling, and in particular to an adaptive well inclination angle closed-loop control method based on real-time formation response identification. Background Technology

[0002] In directional drilling, the drill bit needs to precisely drill along a pre-designed wellbore trajectory to reach the target point underground. The well inclination angle is one of the most critical parameters for controlling the wellbore trajectory. Existing methods mainly rely on the experience of surface engineers or measurement-based closed-loop feedback control. When the drill string traverses formations of varying hardness, abrasiveness, or anisotropy, its directional drilling capability changes significantly. These methods cannot adapt to these changes in real time, leading to lag or mismatch in control commands, making smooth trajectory control difficult, and potentially causing the wellbore trajectory to deviate from the design target. Summary of the Invention

[0003] To address the problems of existing methods, this invention proposes an adaptive wellbore inclination angle method based on real-time formation response identification. Within each control cycle, a real-time build-up capability coefficient characterizing the current formation and drilling tool system response is identified online. Based on this coefficient, an adaptive feedforward control law is used to calculate the required guiding force to achieve the desired build-up rate. Through closed-loop feedback control, this method solves the problems of poor adaptability to formation changes, lag in control response, and low accuracy in directional drilling wellbore inclination angle control. The flowchart of the adaptive wellbore inclination angle control method based on real-time formation response identification is as follows: Figure 1 As shown.

[0004] The specific solution adopted in this invention includes the following steps:

[0005] Step 1, real-time data acquisition and preprocessing, the specific implementation process is as follows:

[0006] Step 1.1: Real-time acquisition of well inclination angle measurements collected by downhole measuring tools during the drilling process. The applied guiding force value .

[0007] Step 1.2: Filter the acquired well inclination angle measurements to obtain smoothed well inclination angle data values. This is to reduce the error caused by measurement noise.

[0008] Step 2: After acquiring real-time data, perform real-time identification of formation response characteristics and calculate the real-time tilting capability coefficient. The specific implementation process is as follows:

[0009] Step 2.1, the control system operates within a preset control cycle. run, It is a fixed time interval.

[0010] Step 2.2, in the At the end of the control cycle, the downhole control unit calculates the current control cycle. Variation of smooth well inclination angle within each control cycle The calculation formula is:

[0011] (1)

[0012] : indicates the first One control cycle.

[0013] : No. The smoothed well inclination angle value at the end of each control cycle.

[0014] : No. The smoothed well inclination angle value at the end of the first control cycle, which is the first... The smoothed well inclination angle value at the start of each control cycle.

[0015] Step 2.3, according to the first Variation of smooth well inclination angle within each control cycle Control cycle time and the applied guiding force Calculate the real-time tilting capacity coefficient of the strata in this cycle. The calculation formula is:

[0016] (2)

[0017] This coefficient characterizes the rate of change of well inclination angle caused by a unit guiding force per unit time in the current formation.

[0018] Step 3: Obtain the desired slope rate required for the current control cycle from the upper-level trajectory planning module. The specific acquisition process is as follows:

[0019] Step 3.1: Obtain the target well inclination angle at the current location based on the wellbore trajectory planning. Then, the change in well inclination is calculated using the latest received well inclination angle measurement value. The specific formula is as follows:

[0020] (3)

[0021] : The target well inclination angle value at the current location.

[0022] : Smoothed well inclination angle data value.

[0023] Step 3.2: The upper-level trajectory planning module calculates the desired slope required to effectively eliminate this deviation in the next control cycle. This new expected slope The command is immediately sent to the underlying adaptive well inclination angle closed-loop control module, which will use this latest command in its next fixed control cycle until it receives an updated command again.

[0024] Step 4: Use the expected slope obtained in Step 3. And the latest updated real-time tilting capability coefficient in step 2. The guiding force required for the next control cycle is calculated based on the adaptive feedforward control law. The specific formula is as follows:

[0025] (4)

[0026] Step 5: The calculated required guiding force is used as a control command and sent to the actuator of the downhole guiding tool.

[0027] Step 6: After completing one control cycle, the system immediately begins the next cycle, repeating steps 1 to 5. This forms a closed-loop control until the well inclination angle reaches the target value.

[0028] Compared with existing technologies, the method proposed in this invention can automatically and quickly adapt to changes in the tilting capacity of different strata, significantly reduce feedback control lag, more accurately track the design trajectory, and achieve a smoother and more reliable tilting process. Attached Figure Description

[0029] Figure 1 This is a flowchart of the method of the present invention;

[0030] Figure 2 This is a schematic diagram illustrating the real-time tilting capability coefficient identification of the control system in a continuous cycle in the embodiment.

[0031] Figure 3 This is a schematic diagram illustrating the update of the desired slope in the upper-level trajectory planning module of the embodiment;

[0032] Figure 4 This is a schematic diagram illustrating the change in the required guiding force command of the control system in a continuous cycle in the embodiment.

[0033] Figure 5 This is a diagram illustrating the overall implementation effect of the present invention in the embodiments. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] Step 1: In an embodiment of the present invention, the control system operates in a continuous cyclic control period. Internal operation, control cycle The time interval was set to 60 seconds based on the drilling tool performance. Data acquisition and filtering employed standard downhole measurement tools and algorithms, and the steering force actuator was a common hydraulic steering system.

[0036] During drilling, formation characteristics become uncertain, and the well inclination angle needs to be adjusted according to geological requirements or drilling design. The drilling system is configured to perform a build-up-de-up-build-up task during drilling, executing 200 control cycles. The initial well inclination angle is set at 18°, with a target well inclination angle of 20° and a desired build-up rate of 0.0005° / s. During the 68th control cycle, formation characteristics change, and the well inclination angle is adjusted according to the drilling design; the target well inclination angle is adjusted to 18°, and the desired build-up rate changes by 0.0010° / s. During the 135th control cycle, the target well inclination is adjusted to 20°, and the desired build-up rate changes by 0.0005° / s.

[0037] Step 2: The control system acquires the current downhole inclination angle measurement value in real time through the drilling measurement system. The applied guiding force value Because the raw measurement data may contain high-frequency noise, the system's measurement values ​​of the well inclination angle... Filtering is performed to obtain a smoother and more reliable wellbore inclination angle estimate. .

[0038] Step 3: At the end of each cycle, calculate the change in well inclination angle within that cycle according to formula (1). Combined with the guiding force applied during this period The real-time formation tilting capacity coefficient applicable to the next cycle is calculated using formula (2). Real-time formation tilting capacity coefficient The updates occur at the adaptive feedforward control layer, and they are strictly at fixed time intervals. The process involves high-frequency cycling at the bottom layer to quickly respond to changes in the formation. The real-time directional drilling capability coefficient identification image in this embodiment is shown below. Figure 2 As shown.

[0039] Step 4: The system uses the latest well inclination angle measurement data and wellbore trajectory to plan the target well inclination angle. Calculate the expected slope. This new The value is immediately sent to the underlying adaptive closed-loop control module. This module will use this latest instruction in its next control cycle until it receives another updated instruction. Desired slope The update occurs in the upper-level trajectory planning module, and can be obtained through methods such as angle-deviation-based tracking, position-deviation-based navigation, and direct-given methods based on global planning. Any method that can provide a reasonable expected build-up rate for downhole closed-loop control is applicable to this invention. The expected build-up rate update change image in this embodiment is shown below. Figure 3 As shown.

[0040] Step 5: Based on the real-time formation tilting capacity coefficient calculated in the previous cycle. And the expected slope rate issued by the upper-level trajectory planning module The value is calculated using formula (4) to determine the guiding force required for the current control cycle. The control system will calculate the required guiding force. As an instruction, it is issued to the actuator of the downhole guiding tool. The required guiding force command change graph in this embodiment is shown below. Figure 4 As shown.

[0041] Step 6: After completing one control cycle, the system immediately begins the next cycle, repeating the iterative loop. This continuous cyclic process constitutes a closed-loop adaptive control system.

[0042] The system performs identification and adjustment operations in each cycle, using steps 2 and 3 to determine the change in well inclination angle from the previous cycle. and the applied guiding force Reassess the real-time formation tilting capacity coefficient Through steps 4 and 5, based on the latest real-time tilting capacity coefficient... and the current expected slope Accordingly, its control actions are adjusted. The well inclination angle control effect image in this embodiment is shown below. Figure 5 As shown.

[0043] In this way, the system continuously reassesses its performance and adjusts its control actions accordingly, ensuring that the wellbore inclination angle precisely follows the predetermined target value. It continuously reassesses the system performance and adjusts its control actions accordingly, thus ensuring that the wellbore trajectory precisely follows the predetermined planned trajectory.

[0044] As can be seen from the above process, the adaptive well inclination angle control method based on real-time formation response identification provided by the present invention can perceive formation changes in real time, effectively overcome the control lag caused by formation changes, and improve the accuracy and reliability of well inclination angle control.

Claims

1. An adaptive well inclination angle control method based on real-time formation response identification, characterized in that: By continuously updating the real-time build-up capability coefficient and dynamically adjusting the guiding force accordingly, a closed-loop adaptive well inclination angle control system is constructed, enabling the well inclination angle to accurately follow the preset target and achieve a smoother and more reliable build-up process. The main steps are as follows: Based on a preset control cycle, the system measures the change in the well inclination angle of the guiding tool within the current control cycle and calculates the real-time build-up capability coefficient of the current formation by combining this with the guiding force applied within that cycle. Then, based on the desired build-up rate issued by the upper-level trajectory planning module, the system uses the latest calculated real-time build-up capability coefficient and an adaptive feedforward control law to reverse-calculate the guiding force to be applied in the next control cycle. This process is continuously repeated, forming a continuously learning and self-correcting adaptive closed-loop control system until the well inclination angle reaches the target value.

2. The adaptive well inclination angle control method based on real-time formation response identification according to claim 1, characterized in that: The applied guiding force is dynamically adjusted by continuously and iteratively calculating the real-time tilting capacity coefficient, including the following steps: Step 1: The control system operates at a preset control cycle. The system operates and acquires the filtered well inclination angle and applied guiding force value in real time for the current control cycle. ; Step 2: Calculate the change in smoothed well inclination angle within the current control cycle. ; Step 3: Based on control cycle Variation in inclination angle of smooth well and the applied guiding force Real-time identification of formation response characteristics and calculation of the real-time directional drilling capability coefficient applicable to the next cycle. , The rate of change of well inclination angle caused by a unit guiding force per unit time is represented by the calculation method shown in Equation (1): (1) Step 4: Obtain the target well inclination angle at the current position based on the wellbore trajectory planning. Calculate the well inclination angle deviation using the latest well inclination angle data. The upper-level trajectory planning module then calculates the expected build-up rate required to eliminate this deviation in the next control cycle based on the well inclination angle deviation. ; Step 5: Apply guiding force to complete the next control cycle The calculation is derived from the adaptive feedforward control law, and the calculation formula is shown in equation (2): (2) in, This is the latest updated real-time tilting capability coefficient; The expected slope rate issued by the upper-level trajectory planning module.

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