Control system and method for blowout preventer in top drive of drilling machine

Abstract

The invention relates to the technical field of drilling equipment, in particular to a control system and method for a blowout preventer in a top drive of a drilling machine, and the system comprises a data collection module which is used for monitoring pressure data, well fluid return quantity, formation fluid height and displacement data; the data analysis module is used for determining the intense degree of pressure fluctuation in the well based on the pressure dynamic response parameters or determining the intense degree of well fluid return quantity fluctuation in the well based on the return flow rate sudden change characteristic value; the mode determining module is used for determining the blowout intensity based on the intensity of the in-well pressure fluctuation and the intensity of the well fluid return quantity fluctuation and determining the closing mode of the upper ball valve; the sliding sleeve analysis module determines whether the closing state of the upper ball valve is qualified or not based on the displacement, determines whether the closing time of the upper ball valve is timely or not according to the formation fluid height and adjusts the rotating speed according to the ratio; and the reset analysis module determines whether the upper ball valve is completely opened or not based on the reset precision so as to determine the adjusting torque according to the difference value, and the response precision of the blowout preventer is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of drilling equipment, and particularly relates to a control system and method for an internal blowout preventer in a top drive of a drilling rig. Background Art

[0002] The internal blowout preventer in the top drive of a drilling rig is a key device for urgently controlling blowouts during oil drilling operations. It is usually installed in the top drive device and blocks the overflow of well fluid by quickly closing the ball valve to ensure the safety of operations. With the increasing demand for drilling in deep wells, ultra-deep wells, and complex formations, higher requirements are imposed on the dynamic response ability, sealing performance, and reliability of the actuator of the internal blowout preventer.

[0003] Chinese Patent Application Publication No.: CN107558944A discloses an oil top drive device and an internal blowout preventer drive assembly, including an internal blowout preventer provided with a plug. It further includes: a guide sleeve sleeved on the outer circle of the internal blowout preventer and capable of moving up and down. A working window is opened at a position corresponding to the plug on the guide sleeve. The upper and lower ends of the guide sleeve are hermetically fitted with the outer circle of the internal blowout preventer; a cam is embedded in each working window, and the outer wall of the cam is in profile fit with the inner wall of the working window. Each cam is fixedly connected to the corresponding plug in the circumferential direction through a connecting rod; a cam cover plate connected to the guide sleeve for enclosing the cam in the working window; and a driving device for driving the guide sleeve to move up and down.

[0004] However, the following problems exist in the prior art: The prior art drives the cam and the connecting rod to control the plug through the guide sleeve, and cannot control the closing response of the blowout preventer according to data monitoring, resulting in a response lag, and thus the problem of low response accuracy of the blowout preventer. Summary of the Invention

[0005] Therefore, the present invention provides a control system and method for an internal blowout preventer in a top drive of a drilling rig to overcome the problem in the prior art that the blowout preventer cannot be controlled according to data monitoring, resulting in a response lag and thus low response accuracy of the blowout preventer.

[0006] To achieve the above object, the present invention provides a control system for an internal blowout preventer in a top drive of a drilling rig, which includes a plug, left and right knobs, and a ball valve, and further includes:

[0007] A sliding mechanism for driving the actuator to move through a driving mechanism;

[0008] A driving mechanism including an oil cylinder provided on the upper part of the sliding mechanism for driving the sliding mechanism;

[0009] An actuator including a wrench holder provided on the body for fixing a wrench, and a wrench provided on the wrench holder for rotating the plug;

[0010] A control mechanism, which is arranged inside the body and includes,

[0011] A data acquisition module, which is used to monitor the pressure data of several monitoring points at the wellhead during the process of lowering the drill pipe, the well fluid return volume, and the formation fluid height between the upper ball valve and the wellhead casing, and monitor the displacement data of the sliding sleeve during the single opening and closing process of the blowout preventer;

[0012] A data analysis module, which is connected to the data acquisition module and is used to determine the severity of the pressure fluctuation in the well based on the pressure dynamic response parameters of the pressure data, or determine the severity of the fluctuation of the well fluid return volume in the well based on the mutation characteristic value of the reflux rate of the well fluid return volume;

[0013] A mode determination module, which is connected to the data analysis module and is used to determine the severity of the blowout based on the severity of the pressure fluctuation in the well and the fluctuation of the well fluid return volume in the well, and determine the closing mode of the upper ball valve;

[0014] A sliding sleeve analysis module, which is connected to the mode determination module and is used to determine whether the closing state of the upper ball valve of the blowout preventer is qualified based on the displacement of the sliding sleeve, determine whether the closing timing of the upper ball valve is timely according to the formation fluid height between the upper ball valve and the wellhead casing, and adjust the rotation speed of the drive motor according to the ratio of the preset height to the height;

[0015] A reset analysis module, which is connected to the mode determination module and is used to determine whether the upper ball valve is fully opened based on the reset accuracy of the sliding sleeve after the drive motor drives the sliding sleeve to reset, and determine the torque of the drive motor to be adjusted according to the difference between the reset accuracy and the reset accuracy threshold.

[0016] Further, the sliding mechanism includes a sliding sleeve arranged at the upper part of the body for rotating the actuator, a slider arranged at the upper part of the sliding sleeve for connecting the sliding sleeve and the slide plate, and a slide plate arranged at the upper part of the slider for driving the sliding sleeve to move up and down.

[0017] Further, the data analysis module determines the severity of the pressure fluctuation in the well according to the comparison result between the pressure dynamic response parameters of the pressure data and the preset pressure dynamic response parameters, where,

[0018] If the pressure dynamic response parameter is less than the preset pressure dynamic response parameter, it is determined that the pressure fluctuation in the well is stable;

[0019] If the pressure dynamic response parameter is greater than or equal to the preset pressure dynamic response parameter, it is determined that the pressure fluctuation in the well is severe.

[0020] Further, the data analysis module determines the severity of the fluctuation of the well fluid return volume in the well according to the comparison result between the mutation characteristic value of the reflux rate of the well fluid return volume and the preset reflux rate mutation characteristic value, where,

[0021] If the reflux rate mutation eigenvalue is less than the preset reflux rate mutation eigenvalue, it is determined that the fluctuation of the well fluid return volume in the well is stable;

[0022] If the reflux rate mutation eigenvalue is greater than or equal to the preset reflux rate mutation eigenvalue, it is determined that the fluctuation of the well fluid return volume in the well is severe.

[0023] Furthermore, the mode determination module determines the severity of the blowout according to the severity of the pressure fluctuation in the well and the severity of the fluctuation of the well fluid return volume in the well, and determines the closing mode of the upper ball valve. Among them,

[0024] If the pressure fluctuation in the well is stable and the fluctuation of the well fluid return volume in the well is stable, it is determined that the blowout is stable, and the closing mode of the upper ball valve of the blowout preventer is the first closing mode;

[0025] If the pressure fluctuation in the well is severe and the fluctuation of the well fluid return volume in the well is severe, it is determined that the blowout is severe, and the closing mode of the upper ball valve of the blowout preventer is the second closing mode.

[0026] Furthermore, the sliding sleeve analysis module determines that the closing state of the upper ball valve is qualified based on the comparison result that the displacement of the sliding sleeve is greater than or equal to the preset displacement, and determines that the closing timing of the upper ball valve is not timely according to the comparison result that the formation fluid height between the upper ball valve and the wellhead casing is greater than the preset height.

[0027] Furthermore, when the sliding sleeve analysis module determines that the closing timing of the upper ball valve is not timely, the process of adjusting the driving motor speed includes:

[0028] Dividing the preset height by the height;

[0029] Setting a number of adjustment coefficients corresponding to the corresponding ratio;

[0030] Increasing the speed of the driving motor based on a number of the adjustment coefficients;

[0031] Setting the corresponding relationship between the corresponding ratio and the increased speed of the driving motor to adjust the speed.

[0032] Furthermore, the reset analysis module determines that the upper ball valve is not fully opened based on the comparison result that the reset accuracy of the sliding sleeve after the driving motor drives the sliding sleeve to reset is greater than the reset accuracy threshold.

[0033] Furthermore, when the reset analysis module determines that the upper ball valve is not fully opened, the process of adjusting the driving motor torque includes:

[0034] Subtracting the reset accuracy from the reset accuracy threshold;

[0035] Setting a number of optimization coefficients corresponding to the corresponding difference;

[0036] Increase the torque of the drive motor based on a number of the optimization coefficients.

[0037] On the other hand, the present invention also provides a control method for an inner blowout preventer of a top drive of a drilling rig, including:

[0038] Obtain the pressure data of several monitoring points at the wellhead during the process of running in the hole, the well fluid return volume, and the formation fluid height between the upper ball valve and the wellhead casing, and also use it to monitor the displacement data of the slip sleeve during the single opening and closing process of the blowout preventer;

[0039] Determine the severity of the pressure fluctuation in the well based on the pressure dynamic response parameter of the pressure data, or determine the severity of the fluctuation of the well fluid return volume in the well based on the sudden change characteristic value of the reverse flow rate of the well fluid return volume;

[0040] Determine the severity of the blowout based on the severity of the pressure fluctuation in the well and the fluctuation of the well fluid return volume in the well, and determine the closing mode of the upper ball valve;

[0041] Determine whether the closing state of the upper ball valve of the blowout preventer is qualified based on the displacement of the slip sleeve, determine whether the closing timing of the upper ball valve is timely according to the formation fluid height between the upper ball valve and the wellhead casing, and adjust the rotational speed of the drive motor according to the ratio of the preset height to the height;

[0042] Determine whether the upper ball valve is fully opened based on the reset accuracy of the slip sleeve after the drive motor drives the slip sleeve to reset, and determine to adjust the torque of the drive motor according to the difference between the reset accuracy and the reset accuracy threshold.

[0043] Compared with the prior art, the beneficial effects of the present invention are that the present invention quickly responds to abnormal conditions in the well by real-time monitoring of key parameters such as the wellhead pressure, well fluid return volume, and formation fluid height, timely adjusts the closing mode of the upper ball valve, timely prevents the occurrence of blowout accidents, ensures the safe progress of the drilling operation, simplifies the operation process through automatic control, reduces manual intervention, improves the operation efficiency, automatically adjusts the rotational speed and torque of the drive motor according to the real-time monitoring data, ensures the accurate and timely closing and full opening of the upper ball valve, realizes the accurate judgment of the pressure fluctuation in the well and the fluctuation of the well fluid return volume, provides reliable data support for the mode determination module, improves the accuracy of the system, and thus improves the accuracy of the response of the blowout preventer.

[0044] Furthermore, the present invention determines the fluctuation degrees of the pressure in the well and the well fluid return volume by comparing the real-time monitoring data with the preset parameters, and determines the severity of the blowout and the closing mode of the upper ball valve accordingly, accurately determines the fluctuation degrees of the pressure in the well and the well fluid return volume, improves the accuracy of well control judgment, effectively responds to different blowout situations, improves the operation efficiency and safety, adapts to different operation environments and conditions, and enhances the versatility and flexibility of the blowout preventer.

[0045] Furthermore, the present invention determines whether the closed state is qualified by comparing the displacement of the sliding sleeve with a preset displacement, and determines whether the closing timing is timely by comparing the formation fluid height with a preset height. Accordingly, the rotational speed of the driving motor is adjusted to ensure that the upper ball valve is closed timely and effectively, improving the blowout prevention performance of the blowout preventer and reducing the wear of the blowout preventer.

[0046] Furthermore, the present invention controls the driving motor in the reverse direction to reset the sliding sleeve to open the upper ball valve, and determines whether the upper ball valve is fully opened according to the comparison result between the reset accuracy and the reset accuracy threshold. Accordingly, the torque of the driving motor is adjusted, and the torque of the driving motor is adjusted according to the actual situation of the reset accuracy to optimize the opening effect of the upper ball valve, reducing the accident risk caused by improper opening of the upper ball valve and enhancing the safety of the operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a schematic structural diagram of the internal blowout preventer of the top drive of the drilling rig in the embodiment of the present invention;

[0048] Figure 2 It is a schematic cross-sectional structural diagram of the valve body in the embodiment of the present invention;

[0049] Figure 3 It is a schematic structural diagram of the control system of the internal blowout preventer of the top drive of the drilling rig in the embodiment of the present invention;

[0050] Figure 4 It is a flowchart of the control method of the internal blowout preventer of the top drive of the drilling rig in the embodiment of the present invention;

[0051] In the figure: 1, body; 101, upper valve seat; 102, upper ball valve; 103, left and right knobs; 104, lower valve seat; 105, lower ball valve; 2, oil cylinder; 3, slide plate; 4, slider; 5, roller; 6, sliding sleeve; 7, wrench holder; 8, wrench; 9, plug cock. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0052] In order to make the objectives and advantages of the present invention clearer, the present invention will be further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0053] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention and do not limit the protection scope of the present invention.

[0054] It should be noted that the data in this embodiment are all obtained through comprehensive analysis and evaluation of the historical detection data and corresponding historical detection results of the present invention in the three months before this detection. Those skilled in the art can understand that the determination method of the above single parameter in the present invention can be to select the value with the highest proportion according to the data distribution as the preset standard parameter, use weighted summation to take the obtained value as the preset standard parameter, substitute each historical data into a specific formula and take the value obtained by using this formula as the preset standard parameter, or other selection methods, as long as it satisfies that the present invention can clearly define different specific situations in the single determination process through the obtained values.

[0055] Please refer to Figures 1 - 3 as shown, which are respectively the structural schematic diagram of the internal blowout preventer of the top drive of the drilling rig in the embodiment of the present invention; the structural cross-sectional diagram of the valve body in the embodiment of the present invention; the structural schematic diagram of the control system of the internal blowout preventer of the top drive of the drilling rig in the embodiment of the present invention.

[0056] The control system of the internal blowout preventer of the top drive of the drilling rig in the embodiment of the present invention includes:

[0057] The body 1, which includes a plug 9, left and right knobs 103 and a ball valve, and is used to carry a sliding mechanism, a driving mechanism, an executing mechanism and a control mechanism;

[0058] The sliding mechanism, which includes a sliding sleeve 6 arranged on the upper part of the body 1 for rotating the executing mechanism, a slider 4 arranged on the upper part of the sliding sleeve 6 for connecting the sliding sleeve 6 and a slide plate 3, and a slide plate 3 arranged on the upper part of the slider 4 for driving the sliding sleeve 6 to move up and down;

[0059] The driving mechanism, which includes an oil cylinder 2 arranged on the upper part of the sliding mechanism for driving the sliding mechanism;

[0060] The executing mechanism, which includes a wrench holder 8 arranged on the body 1 for fixing a wrench 7, and a wrench 7 arranged on the wrench holder 8 for rotating the plug 9.

[0061] The control mechanism, which is arranged inside the body and includes,

[0062] The data acquisition module, which is used to monitor the pressure data of several monitoring points at the wellhead during the process of lowering the drill string, the well fluid return volume, and the formation fluid height between the upper ball valve and the wellhead casing, and monitor the displacement data of the sliding sleeve during a single opening and closing process of the blowout preventer;

[0063] The data analysis module, which is connected to the data acquisition module and is used to determine the severity of the pressure fluctuation in the well based on the pressure dynamic response parameters of the pressure data, or determine the severity of the fluctuation of the well fluid return volume in the well based on the sudden change characteristic value of the backflow rate of the well fluid return volume;

[0064] A mode determination module, which is connected to the data analysis module, is used to determine the severity of a blowout based on the severity of pressure fluctuations in the well and the severity of fluctuations in the return volume of well fluid in the well, and to determine the closing mode of the upper ball valve;

[0065] A sliding sleeve analysis module, which is connected to the mode determination module, is used to determine whether the closing state of the upper ball valve of the blowout preventer is qualified based on the displacement of the sliding sleeve, to determine whether the closing timing of the upper ball valve is timely according to the formation fluid height between the upper ball valve and the wellhead casing, and to adjust the rotational speed of the drive motor according to the ratio of the preset height to the height;

[0066] A reset analysis module, which is connected to the mode determination module, is used to determine whether the upper ball valve is fully opened based on the reset accuracy of the sliding sleeve after the drive motor drives the sliding sleeve to reset, and to determine the torque of the drive motor to be adjusted according to the difference between the reset accuracy and the reset accuracy threshold.

[0067] In an embodiment of the present invention, the plug 9 is used to drive the left and right knobs 103 to rotate to control the opening and closing of the ball valve, and the ball valve includes an upper ball valve 102 and a lower ball valve 105.

[0068] In an embodiment of the present invention, the internal blowout preventer of the top drive of the drilling rig further includes a roller 5, an upper valve seat 402, and a lower valve seat 104.

[0069] In an embodiment of the present invention, the pressure data is measured by a pressure sensor, the return volume of well fluid is measured by an optical liquid level sensor, the formation fluid height is measured by an ultrasonic liquid level sensor installed at the top of the blowout preventer, and the displacement data is measured by a displacement sensor arranged in the sliding sleeve.

[0070] Specifically, the present invention quickly responds to abnormal conditions in the well by real-time monitoring of key parameters such as wellhead pressure, return volume of well fluid, and formation fluid height, timely adjusts the closing mode of the upper ball valve, timely prevents the occurrence of blowout accidents, ensures the safe progress of drilling operations, simplifies the operation process through automatic control, reduces manual intervention, improves operation efficiency, automatically adjusts the rotational speed and torque of the drive motor according to real-time monitoring data, ensures the accurate and timely closing and full opening of the upper ball valve, realizes the accurate judgment of pressure fluctuations in the well and fluctuations in the return volume of well fluid, provides reliable data support for the mode determination module, improves the accuracy of the system, and thus improves the accuracy of the response of the blowout preventer.

[0071] Specifically, the data analysis module determines the severity of pressure fluctuations in the well according to the comparison result between the pressure dynamic response parameter of the pressure data collected during the process of lowering the drill string and the preset pressure dynamic response parameter;

[0072] If the pressure dynamic response parameter is less than the preset pressure dynamic response parameter, it is determined that the pressure fluctuations in the well are stable;

[0073] If the pressure dynamic response parameter is greater than or equal to the preset pressure dynamic response parameter, it is determined that the pressure fluctuation in the well is severe.

[0074] In the embodiment of the present invention, the preset pressure dynamic response parameter is taken as 0.5 MPa / s. The preset pressure dynamic response parameter is obtained when taking the minimum value of the pressure dynamic response parameters during several historical severe pressure fluctuations in the well. However, the above value is not limited to this, and those skilled in the art can also adjust this value according to actual needs.

[0075] During implementation, the pressure dynamic response parameter is the average value of the pressure changes per unit time at several monitoring points, that is, the pressure difference at several monitoring points at consecutive time points divided by the time interval.

[0076] In a specific embodiment, the data analysis module calculates the pressure dynamic response parameter according to the following formula. Set:

[0077]

[0078] where Q represents the pressure dynamic response parameter, n is the number of monitoring points, Δt is the time interval, set to 2 s, P iΔt is the well pressure measured at the i-th monitoring point after the time interval, P i0 is the initial well pressure at the i-th monitoring point.

[0079] It can be understood that when the pressure dynamic response parameter is 0, it means that there is no pressure fluctuation in the well, excluding the possibility of accidents such as blowout and lost circulation. At the same time, the multi-monitoring point data excludes misjudgment of local interference or equipment failure. In actual operation, due to the limitation of sensor accuracy, the pressure dynamic response parameter may be approximately zero with a very small value. This situation still belongs to the category of judging stable pressure fluctuation.

[0080] Specifically, the data analysis module determines the severity of the fluctuation of the well fluid return volume in the well according to the comparison result between the reflux rate mutation characteristic value of the well fluid return volume collected during the tripping operation and the preset reflux rate mutation characteristic value;

[0081] If the reflux rate mutation characteristic value is less than the preset reflux rate mutation characteristic value, it is determined that the fluctuation of the well fluid return volume in the well is stable;

[0082] If the reflux rate mutation characteristic value is greater than or equal to the preset reflux rate mutation characteristic value, it is determined that the fluctuation of the well fluid return volume in the well is severe.

[0083] In the embodiment of the present invention, the preset reflux rate mutation characteristic value is taken as 0.15 m 3 / s 2, the preset reflux rate mutation eigenvalue is obtained when the minimum value of the reflux rate mutation eigenvalue is taken when the fluctuation of the well fluid return volume in the well is severe. However, the above value is not limited to this, and those skilled in the art can also adjust this value according to actual needs.

[0084] During the implementation process, the reflux rate mutation eigenvalue is the average value of the change in the well fluid return volume per unit time at several monitoring points, that is, the difference in the well fluid return volume at several monitoring points at consecutive time points divided by the time interval.

[0085] In a specific embodiment, the data analysis module calculates the reflux rate mutation eigenvalue according to the following formula. Let:

[0086]

[0087] where G represents the reflux rate mutation eigenvalue, m is the number of monitoring points, ΔT is the time interval, set to 1 s, P jΔT is the well fluid return volume measured after the time interval at the jth monitoring point, and P j0 is the initial well fluid return volume at the jth monitoring point.

[0088] It can be understood that when the reflux rate mutation eigenvalue is 0, it means that the well fluid return volume in the well has not fluctuated, that is, there is no blowout accident. In actual operations, due to the limitation of the sensor accuracy, the reflux rate mutation eigenvalue may be approximately zero with a very small value, and this situation still belongs to the category of judging that the well fluid return volume fluctuates smoothly.

[0089] Specifically, the mode determination module determines the blowout severity according to the severity of the pressure fluctuation in the well and the severity of the well fluid return volume fluctuation in the well, and determines the closing mode of the upper ball valve;

[0090] If the pressure fluctuation in the well is stable and the well fluid return volume fluctuation in the well is stable, it is determined that the blowout is stable, and the closing mode of the upper ball valve of the blowout preventer is the first closing mode;

[0091] If the pressure fluctuation in the well is severe and the well fluid return volume fluctuation in the well is severe, it is determined that the blowout is severe, and the closing mode of the upper ball valve of the blowout preventer is the second closing mode.

[0092] In the embodiments of the present invention, the first closing mode is that the closing time of the ball valve is 5 s to 10 s, preferably 7 s. At this time, the rotational speed of the driving motor is 200 rpm to 300 rpm, preferably 260 rpm, and the torque is 150 Nm to 300 Nm, preferably 200 Nm. The second closing mode is that the closing time of the ball valve is 1 s to 3 s, preferably 2 s. At this time, the rotational speed of the driving motor is 800 rpm to 1200 rpm, preferably 1000 rpm, and the torque is 400 Nm to 600 Nm, preferably 500 Nm. In practice, the value ranges and preferred values of the rotational speed, torque, and ball valve closing time can be determined according to the actual situation. The type of the driving motor is one of a permanent magnet synchronous motor or a switched reluctance motor, which is not specifically limited here and will not be elaborated further.

[0093] It can be understood that the first closing mode is a progressive closing to avoid pressure shocks. For low-risk fluctuations, conservative operations are mainly adopted. During closing, the pressure and the feedback of the return flow rate are monitored in real time. If the fluctuations turn violent, it will automatically switch to the second closing mode. The second closing mode is a forced rapid locking. For high-risk blowout signs, it is preferred to block the wellbore pressure conduction and minimize the well control response time.

[0094] Specifically, the present invention determines the degree of fluctuations in the well pressure and the well fluid return volume by comparing the real-time monitoring data with the preset parameters, and accordingly determines the severity of the blowout and the upper ball valve closing mode. It accurately determines the degree of fluctuations in the well pressure and the well fluid return volume, improves the accuracy of well control judgment, effectively responds to different blowout situations, improves the operation efficiency and safety, adapts to different operation environments and conditions, and enhances the versatility and flexibility of the blowout preventer.

[0095] Specifically, under the condition of determining the closing mode of the upper ball valve, the driving motor controls the oil cylinder to drive the sliding sleeve to move. The movement of the sliding sleeve drives the wrench to rotate, so that the left and right knobs inside the blowout preventer rotate, and the left and right knobs rotate to control the closing of the upper ball valve.

[0096] Specifically, the sliding sleeve analysis module determines whether the closing state of the upper ball valve of the blowout preventer is qualified according to the comparison result between the displacement of the sliding sleeve and the preset displacement.

[0097] If the displacement is less than the preset displacement, it is determined that the closing state of the upper ball valve is unqualified.

[0098] If the displacement is greater than or equal to the preset displacement, it is determined that the closing state of the upper ball valve is qualified.

[0099] In the embodiment of the present invention, the preset displacement is 190 mm. The preset displacement is obtained by taking the average value of the displacement rates of the upper ball valve in a qualified closed state in the past. However, the above value is not limited to this, and those skilled in the art can also adjust this value according to actual needs.

[0100] During the implementation process, the displacement is the product of the displacement rate of the sliding sleeve during the closing process of the upper ball valve and the displacement time, and the displacement rate is controlled by the driving motor.

[0101] In the embodiment of the present invention, the closed state is the closed state when the upper ball valve just contacts the upper valve seat or the interference fit contact state between the upper ball valve and the upper valve seat. It can be understood that an interference fit contact can be adopted between the valve seat and the sphere to improve the initial sealing performance.

[0102] During the implementation process, when the displacement is equal to the preset displacement, the closed state at this time is the closed state when the upper ball valve just contacts the upper valve seat. When the displacement is greater than the preset displacement, the closed state at this time is the interference fit contact between the upper ball valve and the upper valve seat. The allowable range of the sliding sleeve displacement exceeding the interference fit contact is 0.2 mm to 0.5 mm, preferably 0.3 mm, that is, the displacement in the interference fit contact state is 190.2 mm to 190.5 mm.

[0103] Specifically, under the condition of determining that the closing state of the blowout preventer is unqualified, it is determined that the upper ball valve fails, and the lower ball valve is manually started in time to prevent a blowout, and the upper ball valve is replaced at the same time.

[0104] Specifically, under the condition of determining that the closing state of the blowout preventer is qualified, the sliding sleeve analysis module determines whether the closing timing of the upper ball valve is timely according to the comparison result between the formation fluid height between the upper ball valve and the wellhead casing and the preset height;

[0105] If the height is less than or equal to the preset height, it is determined that the closing timing of the upper ball valve is timely;

[0106] When the height is greater than the preset height, it is determined that the closing timing of the upper ball valve is not timely.

[0107] In the embodiment of the present invention, the preset height is 15 cm. The preset height is obtained by taking the average value of the formation fluid height when the upper ball valve is closed in time. However, the above value is not limited to this, and those skilled in the art can also adjust this value according to actual needs.

[0108] During the implementation process, the formation fluid height is the height of the liquid in the blowout preventer with the horizontal plane of the upper surface of the upper ball valve as the reference point, and is measured by the ultrasonic liquid level sensor installed at the top of the blowout preventer.

[0109] Specifically, when the sliding sleeve analysis module determines that the closing time of the upper ball valve is not timely, it determines the rotation speed of the driving motor according to the comparison result between the ratio of the preset height to the height and the preset ratio.

[0110] If the ratio is less than or equal to the preset ratio, it is determined to increase the rotation speed of the driving motor to the corresponding value with the first preset rotation speed adjustment coefficient of 1.05.

[0111] If the ratio is greater than the preset ratio, it is determined to increase the rotation speed of the driving motor to the corresponding value with the second preset rotation speed adjustment coefficient of 1.12.

[0112] The ratio is the ratio of the preset height to the height.

[0113] In the embodiment of the present invention, the preset ratio is taken as 0.55, but the above value is not limited to this, and those skilled in the art can also adjust this value according to actual needs.

[0114] In the embodiment of the present invention, the increased rotation speed of the driving motor is the product of the rotation speed and the preset rotation speed adjustment coefficient. The preset rotation speed adjustment coefficient includes the first preset rotation speed adjustment coefficient with a value of 1.05; the second preset rotation speed adjustment coefficient with a value of 1.12. To ensure that the adjusted rotation speed meets the actual requirements and the adjustment range is not too large, the adjustment coefficient is correspondingly set to control the adjustment range. The rotation speed includes the rotation speeds in the first closing mode and the second closing mode.

[0115] Specifically, in the present invention, it is determined whether the closing state is qualified by comparing the displacement of the sliding sleeve with the preset displacement, and it is determined whether the closing time is timely by comparing the formation fluid height with the preset height. Accordingly, the rotation speed of the driving motor is adjusted to ensure that the upper ball valve closes timely and effectively, improving the blowout prevention performance of the blowout preventer and reducing the wear of the blowout preventer.

[0116] Specifically, after the upper ball valve is closed, a well killing operation is performed on the wellbore. The well killing operation is one of the positive circulation well killing or the perfusion method well killing. After the well killing is successful and the wellbore pressure is stable, the driving motor reversely controls the oil cylinder to drive the sliding sleeve to reset. The reset of the sliding sleeve drives the wrench to rotate and reset, so that the left and right knobs in the blowout preventer rotate, and the left and right knobs rotate to control the upper ball valve to open.

[0117] Specifically, the reset analysis module determines whether the upper ball valve is fully opened according to the comparison result between the reset accuracy of the sliding sleeve after the driving motor drives the sliding sleeve to reset and the reset accuracy threshold.

[0118] If the reset accuracy is less than or equal to the reset accuracy threshold, it is determined that the upper ball valve is fully opened.

[0119] If the reset accuracy is greater than the reset accuracy threshold, it is determined that the upper ball valve is not fully opened.

[0120] In the embodiment of the present invention, the reset accuracy threshold is set to 0.5%. The reset accuracy threshold is obtained under the condition of the maximum reset accuracy when the upper ball valve is fully opened. However, the above value is not limited to this, and those skilled in the art can also adjust this value according to actual needs.

[0121] During the implementation process, the reset accuracy is the result of multiplying 100% by the ratio of the absolute value of the difference between the displacement of the sliding sleeve after actual reset and the displacement of the sliding sleeve when the upper ball valve is fully closed to the displacement of the sliding sleeve when the upper ball valve is fully closed.

[0122] Specifically, when the reset analysis module determines that the upper ball valve is not fully opened, it determines the torque of the adjustment drive motor according to the comparison result of the difference between the reset accuracy and the reset accuracy threshold and a preset difference.

[0123] If the difference is less than or equal to the preset difference, it is determined to increase the speed of the drive motor to the corresponding value with a first preset torque optimization coefficient of 1.10.

[0124] If the difference is greater than the preset difference, it is determined to increase the speed of the drive motor to the corresponding value with a second preset torque optimization coefficient of 1.20.

[0125] The difference is the difference between the reset accuracy and the reset accuracy threshold.

[0126] In the embodiment of the present invention, the preset difference is set to 0.05. However, the above value is not limited to this, and those skilled in the art can also adjust this value according to actual needs.

[0127] In the embodiment of the present invention, the increased torque of the drive motor is the product of the torque and the preset torque optimization coefficient. The preset torque optimization coefficient includes a first preset torque optimization coefficient with a value of 1.10 and a second preset torque optimization coefficient with a value of 1.20. To ensure that the adjusted torque meets the actual requirements and the adjustment range should not be too large, a corresponding adjustment coefficient is set to control the adjustment range. The torque includes the torque in the first closing mode and the second closing mode.

[0128] Specifically, the present invention controls the reset of the sliding sleeve in the reverse direction by the drive motor to open the upper ball valve, determines whether the upper ball valve is fully opened according to the comparison result of the reset accuracy and the reset accuracy threshold, adjusts the torque of the drive motor accordingly, and adjusts the torque of the drive motor according to the actual situation of the reset accuracy to optimize the opening effect of the upper ball valve, reduce the accident risk caused by improper opening of the upper ball valve, and enhance the safety of the operation.

[0129] Please refer to Figure 4 as shown, which is the flowchart of the control method of the internal blowout preventer of the top drive of the drilling rig in the embodiment of the present invention.

[0130] On the other hand, the present invention also provides a control method for the internal blowout preventer of a rig top drive, including:

[0131] Step S1: Obtain the pressure data of several monitoring points at the wellhead during the process of running in the hole, the well fluid return volume, and the formation fluid height between the upper ball valve and the wellhead casing, and also monitor the displacement data of the sliding sleeve during a single opening and closing process of the blowout preventer;

[0132] Step S2: Determine the severity of the pressure fluctuation in the well based on the pressure dynamic response parameter of the pressure data, or determine the severity of the fluctuation of the well fluid return volume in the well based on the sudden change characteristic value of the reflux rate of the well fluid return volume;

[0133] Step S3: Determine the severity of the blowout based on the severity of the pressure fluctuation and the well fluid return volume fluctuation in the well, and determine the closing mode of the upper ball valve;

[0134] Step S4: Determine whether the closing state of the upper ball valve of the blowout preventer is qualified based on the displacement of the sliding sleeve, determine whether the closing timing of the upper ball valve is timely according to the formation fluid height between the upper ball valve and the wellhead casing, and adjust the rotation speed of the drive motor according to the ratio of the preset height to the height;

[0135] Step S5: Determine whether the upper ball valve is fully opened based on the reset accuracy of the sliding sleeve after the drive motor drives the sliding sleeve to reset, and determine the torque of the drive motor to be adjusted according to the difference between the reset accuracy and the reset accuracy threshold.

[0136] So far, the technical solution of the present invention has been described in combination with the preferred embodiments shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or replacements to the relevant technical features, and the technical solutions after these changes or replacements will all fall within the protection scope of the present invention.

[0137] The above are only the preferred embodiments of the present invention and are not used to limit the present invention; for those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A control system for a blowout preventer in a top drive of a drilling rig, comprising a plug, left and right knobs and a ball valve, characterized in that: Also includes: A sliding mechanism, which is used to drive the actuator to move through the driving mechanism; A driving mechanism, comprising an oil cylinder disposed on the upper portion of the sliding mechanism for driving the sliding mechanism; An actuator, comprising a wrench frame arranged on the body for fixing a wrench, and a wrench arranged on the wrench frame for rotating the cock; A control mechanism, which is arranged inside the body, comprises: The data acquisition module is used to monitor the pressure data of several monitoring points at the wellhead during the drilling process, the amount of well fluid return, and the formation fluid height between the upper ball valve and the wellhead casing, and to monitor the displacement data of the sliding sleeve of the blowout preventer during a single opening and closing process; A data analysis module connected to the data acquisition module, for determining the severity of the pressure fluctuation in the well based on the pressure dynamic response parameter of the pressure data, or determining the severity of the fluctuation of the well fluid return amount in the well based on the reflux rate mutation characteristic value of the well fluid return amount; A mode determination module, which is connected to the data analysis module, is used to determine the severity of the blowout based on the severity of the fluctuation of the well pressure and the fluctuation of the well fluid return volume, and determine the closing mode of the upper ball valve; A sleeve analysis module, which is connected to the mode determination module, is used to determine whether the closing state of the upper ball valve of the blowout preventer is qualified based on the displacement of the sleeve, to determine whether the closing timing of the upper ball valve is timely according to the formation fluid height between the upper ball valve and the wellhead casing, and to adjust the speed of the driving motor according to the ratio of the preset height to the height; A reset analysis module is connected to the mode determination module and is used to determine whether the upper ball valve is fully opened based on the reset accuracy of the sleeve after the drive motor drives the sleeve to reset, so as to adjust the torque of the drive motor according to the difference between the reset accuracy and the reset accuracy threshold.

2. The control system of the blowout preventer in the top drive of the drilling rig according to claim 1, characterized in that: The sliding mechanism includes a sliding sleeve arranged on the upper part of the body for rotating the actuator, a sliding block arranged on the upper part of the sliding sleeve for connecting the sliding sleeve and a sliding plate, and a sliding plate arranged on the upper part of the sliding block for driving the sliding sleeve to move up and down.

3. The control system of the blowout preventer in the top drive of the drilling rig according to claim 2, characterized in that: The data analysis module determines the severity of the pressure fluctuation in the well according to the comparison result of the pressure dynamic response parameter of the pressure data and the preset pressure dynamic response parameter, wherein: If the pressure dynamic response parameter is less than the preset pressure dynamic response parameter, it is determined that the pressure fluctuation in the well is stable; If the pressure dynamic response parameter is greater than or equal to the preset pressure dynamic response parameter, it is determined that the pressure in the well fluctuates violently.

4. The control system of the blowout preventer in the top drive of the drilling rig according to claim 3, characterized in that: The data analysis module determines the severity of the fluctuation of the well fluid return volume in the well according to the comparison result of the backflow rate mutation characteristic value of the well fluid return volume and the preset backflow rate mutation characteristic value, wherein: If the return flow rate mutation characteristic value is less than the preset return flow rate mutation characteristic value, it is determined that the return flow amount of the well fluid in the well is fluctuating steadily; If the return flow rate mutation characteristic value is greater than or equal to the preset return flow rate mutation characteristic value, it is determined that the return amount of well fluid in the well fluctuates violently.

5. The control system of the blowout preventer in the top drive of a drilling rig according to claim 4, characterized in that: The mode determination module determines the severity of the blowout according to the severity of the pressure fluctuation in the well and the severity of the well fluid return fluctuation in the well, and determines the closing mode of the upper ball valve, wherein: If the pressure fluctuation in the well is stable and the return amount of well fluid in the well is stable, it is determined that the blowout is stable and the closing mode of the ball valve on the blowout preventer is the first closing mode; If the pressure in the well fluctuates violently and the return amount of the well fluid in the well fluctuates violently, it is determined that the blowout is violent and the closing mode of the ball valve on the blowout preventer is the second closing mode.

6. The control system of the blowout preventer in the top drive of a drilling rig according to claim 5, characterized in that: The sleeve analysis module determines that the closing state of the upper ball valve is qualified based on the comparison result that the displacement of the sleeve is greater than or equal to the preset displacement, and determines that the closing timing of the upper ball valve is untimely based on the comparison result that the formation fluid height between the upper ball valve and the wellhead casing is greater than the preset height.

7. The control system of the blowout preventer in the top drive of a drilling rig according to claim 6, characterized in that: The process of adjusting the speed of the driving motor by the sleeve analysis module under the condition that the closing timing of the upper ball valve is determined to be untimely includes: Dividing a preset height by the height; Setting a number of adjustment coefficients corresponding to the corresponding ratios; Increasing the speed of the drive motor based on the plurality of adjustment coefficients; A corresponding relationship between the corresponding ratio and the increase in the rotation speed of the driving motor is set to adjust the rotation speed.

8. The control system of the blowout preventer in the top drive of a drilling rig according to claim 7, characterized in that: The reset analysis module determines that the upper ball valve is not fully opened based on a comparison result that the reset accuracy of the sliding sleeve is greater than a reset accuracy threshold after the driving motor drives the sliding sleeve to reset.

9. The control system of the blowout preventer in the top drive of a drilling rig according to claim 8, characterized in that: The process of adjusting the torque of the driving motor by the reset analysis module under the condition that the upper ball valve is determined to be not fully opened includes: Subtract the reset accuracy from the reset accuracy threshold; Setting a number of optimization coefficients corresponding to the corresponding differences; The torque of the drive motor is increased based on the plurality of optimization coefficients.

10. A method for controlling a blowout preventer in a top drive of a drilling rig, using the control system of the blowout preventer in a top drive of a drilling rig according to any one of claims 1 to 9, characterized in that: include: Obtain the pressure data of several monitoring points at the wellhead during the drilling process, the amount of well fluid return, and the formation fluid height between the upper ball valve and the wellhead casing. It is also used to monitor the displacement data of the sliding sleeve of the blowout preventer during a single opening and closing process. Determine the severity of the pressure fluctuation in the well based on the pressure dynamic response parameter of the pressure data, or determine the severity of the fluctuation of the well fluid return amount in the well based on the return rate mutation characteristic value of the well fluid return amount; Determine the severity of the blowout based on the severity of the well pressure fluctuation and the well fluid return volume fluctuation, and determine the closing mode of the upper ball valve; Determine whether the closing state of the upper ball valve of the blowout preventer is qualified based on the displacement of the sliding sleeve, determine whether the closing timing of the upper ball valve is timely according to the formation fluid height between the upper ball valve and the wellhead casing, and adjust the speed of the driving motor according to the ratio of the preset height to the height; Whether the upper ball valve is fully opened is determined based on the reset accuracy of the sliding sleeve after the driving motor drives the sliding sleeve to reset, so as to adjust the torque of the driving motor according to the difference between the reset accuracy and the reset accuracy threshold.

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