A control system and method for a top drive blowout preventer

Abstract

The present application relates to drilling equipment technical field, especially to a kind of control system and method of top drive blowout preventer of drilling rig, comprising: data acquisition module, to monitor pressure data, well fluid return, formation fluid height and displacement data;Data analysis module, based on pressure dynamic response parameter determines the severity of wellbore pressure fluctuation, or based on the severity of well fluid return fluctuation of wellbore well fluid return rate mutation characteristic value;Mode determination module, based on the severity of wellbore pressure fluctuation and well fluid return fluctuation determines the severity of blowout, and determines the closing mode of upper ball valve;Sliding sleeve analysis module, based on displacement determines whether the closing state of upper ball valve is qualified, according to formation fluid height determines whether the closing timing of upper ball valve is timely, according to ratio adjusts speed;Reset analysis module, based on reset accuracy determines whether upper ball valve is completely opened, to determine adjustment torque according to difference, the present application improves the accuracy of blowout preventer response.

Description

Technical Field

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

[0002] The internal blowout preventer (BOP) in the top drive of a drilling rig is a key device used for emergency blowout control in oil drilling operations. It is usually installed in the top drive device and blocks the overflow of fluid in the well by quickly closing the ball valve to ensure operation safety. With the increasing demand for drilling deep wells, ultra-deep wells and complex formations, the dynamic response capability, sealing performance and reliability of the actuator of the internal blowout preventer are facing higher requirements.

[0003] Chinese patent application publication number: CN107558944A discloses a petroleum top drive device and an internal blowout preventer drive assembly, including an internal blowout preventer, which is provided with a plug, and also includes: a guide sleeve mounted on the outer circle of the internal blowout preventer and capable of upward and downward movement, the guide sleeve having working windows defined at positions corresponding to the plug, the upper and lower ends of the guide sleeve both sealingly engaging with the outer circle of the internal blowout preventer; a cam embedded in each working window, the outer wall of the cam engaging with the inner wall profile of the working window, each cam being fixedly connected in the circumferential direction to its corresponding plug via a connecting rod; a cam cover plate connected to the guide sleeve for enclosing the cam within the working window; and a drive device for driving the guide sleeve to move upward and downward.

[0004] However, the existing technology has the following problems: the existing technology 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 based on data monitoring, resulting in a response lag and thus low response accuracy of the blowout preventer. Summary of the Invention

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

[0006] To achieve the above object, the present invention provides a control system for a 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, which is used to drive the actuator to move through the driving mechanism;

[0008] A driving mechanism, comprising an oil cylinder disposed on an upper portion of the sliding mechanism for driving the sliding mechanism;

[0009] An actuator comprising a wrench rack provided on the body for fixing a wrench, and a wrench provided on the wrench rack for rotating the cock;

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

[0011] 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;

[0012] a data analysis module connected to the data acquisition module, configured to determine the severity of the pressure fluctuation in the well based on the pressure dynamic response parameter of the pressure data, or to determine the severity of the fluctuation of the well fluid return volume in the well based on the return flow rate mutation characteristic value of the well fluid return volume;

[0013] a mode determination module connected to the data analysis module, for determining the severity of the blowout based on the severity of the fluctuations in the well pressure and the well fluid return volume, and determining the closing mode of the upper ball valve;

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

[0015] 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 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.

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

[0017] Furthermore, 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:

[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 in the well fluctuates violently.

[0020] Furthermore, the data analysis module determines the severity of the fluctuation of the well fluid return volume according to the comparison result of the return rate mutation characteristic value of the well fluid return volume and the preset return rate mutation characteristic value, wherein:

[0021] If the return flow rate mutation characteristic value is less than the preset return flow rate mutation characteristic value, it is determined that the fluctuation of the well fluid return amount in the well is stable;

[0022] 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 flow amount of the well fluid in the well fluctuates violently.

[0023] Furthermore, the mode determination module determines the severity of the blowout according to the severity of the well pressure fluctuation and the severity of the well fluid return fluctuation, and determines the closing mode of the upper ball valve, wherein:

[0024] If the well pressure fluctuations are stable and the well fluid return volume fluctuations are 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;

[0025] If the pressure in the well fluctuates violently and the return flow of well fluid in the well fluctuates violently, it is determined that the blowout is severe and the closing mode of the ball valve on the blowout preventer is the second closing mode.

[0026] Furthermore, 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.

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

[0028] Dividing the preset height by the height;

[0029] Set a number of adjustment coefficients corresponding to the corresponding ratios;

[0030] increasing the speed of the drive motor based on the plurality of adjustment coefficients;

[0031] A corresponding relationship between the corresponding ratio and the increase in the rotational speed of the driving motor is set to adjust the rotational speed.

[0032] Furthermore, 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.

[0033] Furthermore, the reset analysis module adjusts the driving motor torque under the condition that the upper ball valve is determined to be not fully opened, and the process includes:

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

[0035] Set several optimization coefficients corresponding to the corresponding differences;

[0036] The torque of the drive motor is increased based on the plurality of optimization coefficients.

[0037] Another aspect of the present invention provides a method for controlling a blowout preventer in a top drive of a drilling rig, comprising:

[0038] Obtain pressure data, fluid return volume, and formation fluid height between the upper ball valve and the wellhead casing at several monitoring points at the wellhead during the drilling process. It is also used to monitor the displacement data of the sliding sleeve of the blowout preventer during a single opening and closing process.

[0039] 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 volume in the well based on the return rate mutation characteristic value of the well fluid return volume;

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

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

[0042] Whether the upper ball valve is fully opened is determined based on the reset accuracy of the sliding sleeve after the sliding sleeve is reset by the driving motor, so as to adjust the torque of the driving motor according to the difference between the reset accuracy and the reset accuracy threshold.

[0043] Compared with the prior art, the beneficial effect of the present invention lies in that, by real-time monitoring of key parameters such as wellhead pressure, well fluid return volume and formation fluid height, the present invention can quickly respond to abnormal conditions in the well, timely adjust the closing mode of the upper ball valve, and timely prevent the occurrence of blowout accidents, thereby ensuring the safe progress of drilling operations. Automated control simplifies the operating process, reduces manual intervention, and improves operating efficiency. The speed and torque of the drive motor are automatically adjusted according to real-time monitoring data to ensure the accurate and timely closing and full opening of the upper ball valve, thereby achieving accurate judgment of well pressure fluctuations and well fluid return volume fluctuations, providing reliable data support for the mode determination module, improving the accuracy of the system, and thus improving the accuracy of the blowout preventer response.

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

[0045] Furthermore, the present invention determines whether the closing state is qualified by comparing the displacement of the sleeve with the preset displacement, and determines whether the closing timing is timely based on the comparison of the formation fluid height with the preset height. The driving motor speed is adjusted accordingly to ensure that the upper ball valve is closed in a timely and effective manner, thereby improving the blowout prevention performance of the blowout preventer and reducing the wear of the blowout preventer.

[0046] Furthermore, the present invention controls the reset of the sleeve by the reverse control of the driving motor to open the upper ball valve, and determines whether the upper ball valve is fully opened based on the comparison result of the reset accuracy and the reset accuracy threshold, and adjusts the torque of the driving motor accordingly. According to the actual situation of the reset accuracy, the torque of the driving motor is adjusted to optimize the opening effect of the upper ball valve, thereby reducing the risk of accidents caused by improper opening of the upper ball valve and enhancing the safety of the operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is a schematic structural diagram of a blowout preventer in a top drive of a drilling rig according to an embodiment of the present invention;

[0048] Figure 2 This is a schematic structural cross-sectional view of a valve body according to an embodiment of the present invention;

[0049] Figure 3 This is a schematic structural diagram of a control system for a blowout preventer in a top drive of a drilling rig according to an embodiment of the present invention;

[0050] Figure 4 This is a flow chart of a method for controlling a blowout preventer in a top drive of a drilling rig according to an embodiment of the present invention;

[0051] In the figure: 1. Main body; 101. Upper valve seat; 102. Upper ball valve; 103. Left and right knobs; 104. Lower valve seat; 105. Lower ball valve; 2. Cylinder; 3. Slide plate; 4. Slider; 5. Roller; 6. Sleeve; 7. Wrench holder; 8. Wrench; 9. Plug. DETAILED DESCRIPTION

[0052] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are merely used to explain the present invention and are not intended to limit the present invention.

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

[0054] It should be pointed out that the data in this embodiment are obtained by comprehensive analysis and evaluation of the historical test data and the corresponding historical test results of the three months before this test. It can be understood by those skilled in the art that the present invention can determine the above parameters for a single item by selecting the value with the highest proportion as the preset standard parameter based on the data distribution, using weighted summation to use the obtained value as the preset standard parameter, substituting each historical data into a specific formula and using the value obtained by the formula as the preset standard parameter or other selection methods, as long as the present invention can clearly define the different specific situations in the single determination process through the obtained values.

[0055] See also Figures 1-3 As shown, they are respectively a structural schematic diagram of a blowout preventer in a top drive of a drilling rig according to an embodiment of the present invention; a structural cross-sectional schematic diagram of a valve body according to an embodiment of the present invention; and a structural schematic diagram of a control system of a blowout preventer in a top drive of a drilling rig according to an embodiment of the present invention.

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

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

[0058] A sliding mechanism comprising a sleeve 6 disposed on the upper portion of the body 1 for rotating the actuator, a slider 4 disposed on the upper portion of the sleeve 6 for connecting the sleeve 6 and the slide 3, and a slide 3 disposed on the upper portion of the slider 4 for driving the sleeve 6 to move up and down;

[0059] A driving mechanism, comprising an oil cylinder 2 provided on the upper portion of the sliding mechanism for driving the sliding mechanism;

[0060] The actuator includes a wrench frame 8 provided on the body 1 for fixing a wrench 7 , and a wrench 7 provided on the wrench frame 8 for rotating the cock 9 .

[0061] A control mechanism, which is arranged inside the body, includes:

[0062] 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;

[0063] a data analysis module connected to the data acquisition module, configured to determine the severity of the pressure fluctuation in the well based on the pressure dynamic response parameter of the pressure data, or to determine the severity of the fluctuation of the well fluid return volume in the well based on the return flow rate mutation characteristic value of the well fluid return volume;

[0064] a mode determination module connected to the data analysis module, for determining the severity of the blowout based on the severity of the well pressure fluctuation and the severity of the well fluid return volume fluctuation, and determining the closing mode of the upper ball valve;

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

[0066] 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 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.

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

[0068] In the embodiment of the present invention, the blowout preventer in the top drive of the drilling rig further includes a roller 5 , an upper valve seat 101 and a lower valve seat 104 .

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

[0070] Specifically, the present invention monitors key parameters such as wellhead pressure, well fluid return volume, and formation fluid height in real time, quickly responds to abnormal conditions in the well, promptly adjusts the closing mode of the upper ball valve, and promptly prevents the occurrence of blowout accidents, thereby ensuring the safe progress of drilling operations. Automated control simplifies the operating process, reduces manual intervention, and improves operating efficiency. The speed and torque of the drive motor are automatically adjusted according to real-time monitoring data to ensure the accurate and timely closing and full opening of the upper ball valve, thereby achieving accurate judgment of fluctuations in well pressure and well fluid return volume, providing reliable data support for the mode determination module, improving the accuracy of the system, and thus improving the accuracy of the blowout preventer response.

[0071] Specifically, the data analysis module determines the severity of the pressure fluctuation in the well based on the comparison result of the pressure dynamic response parameter of the pressure data collected during the drilling process with 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 fluctuation in the well is 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 in the well fluctuates violently.

[0074] In the embodiment of the present invention, the preset pressure dynamic response parameter is set to 0.5 MPa / s. The preset pressure dynamic response parameter is obtained when the pressure dynamic response parameter takes the minimum value when the well pressure fluctuates violently several times in history. However, the above value is not limited to this. Those skilled in the art can also adjust the value according to actual needs.

[0075] During implementation, the pressure dynamic response parameter is the average value of the pressure change 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: ;

[0077] in, represents the pressure dynamic response parameter, is the number of monitoring points, For the time interval, set it to 2s. is the well pressure measured after the time interval at the i-th monitoring point, is the initial wellbore pressure at the i-th monitoring point.

[0078] It is understandable that when the pressure dynamic response parameter is 0, it means that the pressure in the well has not fluctuated, eliminating the possibility of accidents such as blowouts and well leakage. At the same time, data from multiple monitoring points eliminate the misjudgment of local interference or equipment failure. In actual operations, due to the limitation of sensor accuracy, the pressure dynamic response parameter may be close to zero at a minimum value. This situation still falls within the judgment category of stable pressure fluctuations.

[0079] 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 of the return rate mutation characteristic value of the well fluid return volume collected during the drilling process with the preset return rate mutation characteristic value;

[0080] If the return flow rate mutation characteristic value is less than the preset return flow rate mutation characteristic value, it is determined that the fluctuation of the well fluid return amount in the well is stable;

[0081] 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 flow amount of the well fluid in the well fluctuates violently.

[0082] In the embodiment of the present invention, the preset reflux rate mutation characteristic value is 0.15 m³ / s². The preset reflux rate mutation characteristic value is obtained when the reflux rate mutation characteristic value takes the minimum value when the well fluid return volume in the well fluctuates violently. However, the above value is not limited to this, and those skilled in the art can also adjust the value according to actual needs.

[0083] During implementation, the characteristic value of the return rate mutation 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.

[0084] In a specific embodiment, the data analysis module calculates the reflux rate mutation characteristic value according to the following formula, setting: ;

[0085] in, represents the characteristic value of the reflux rate mutation, is the number of monitoring points, For the time interval, set it to 1s. is the return volume of well fluid measured after the time interval at the jth monitoring point, is the initial well fluid return volume of the jth monitoring point.

[0086] It is understandable that when the characteristic value of the return flow rate mutation is 0, it means that the return flow volume in the well has not fluctuated, that is, no blowout accident has occurred. In actual operation, due to the limitation of sensor accuracy, the characteristic value of the return flow rate mutation may be close to zero at a minimum value. This situation still falls within the judgment category of stable fluctuation of the return flow volume.

[0087] Specifically, the mode determination module determines the severity of the blowout according to the severity of the well pressure fluctuation and the severity of the well fluid return fluctuation, and determines the closing mode of the upper ball valve;

[0088] If the well pressure fluctuations are stable and the well fluid return volume fluctuations are 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;

[0089] If the pressure in the well fluctuates violently and the return flow of well fluid in the well fluctuates violently, it is determined that the blowout is severe and the closing mode of the ball valve on the blowout preventer is the second closing mode.

[0090] In an embodiment of the present invention, the first closing mode is that the ball valve closing time is 5s to 10s, preferably 7s, and the speed of the drive motor at this time is 200rpm to 300rpm, preferably 260rpm, and the torque is 150Nm to 300Nm, preferably 200Nm; the second closing mode is that the ball valve closing time is 1s to 3s, preferably 2s, and the speed of the drive motor at this time is 800rpm to 1200rpm, preferably 1000rpm, and the torque is 400Nm to 600Nm, preferably 500Nm. In implementation, the value range and preferred value of the speed, torque and ball valve closing time can be determined according to actual conditions. The type of the drive motor is a permanent magnet synchronous motor or a switched reluctance motor, which is not specifically limited here and will not be repeated.

[0091] It can be understood that the first closing mode is a progressive closing to avoid pressure shock. For low-risk fluctuations, conservative operations are mainly adopted. While closing, the pressure and return flow feedback are monitored in real time. If the fluctuation becomes severe, it will automatically switch to the second closing mode. The second closing mode is forced rapid locking. For high-risk blowout signs, the wellbore pressure transmission is blocked first to minimize the well control response time.

[0092] Specifically, the present invention determines the degree of fluctuation of the wellbore pressure and the return volume of well fluid by comparing real-time monitoring data with preset parameters, and accordingly determines the severity of the blowout and the closing mode of the upper ball valve, accurately determines the degree of fluctuation of the wellbore pressure and the return volume of well fluid, improves the accuracy of well control judgment, effectively responds to different blowout situations, improves operational efficiency and safety, adapts to different operating environments and conditions, and enhances the versatility and flexibility of the blowout preventer.

[0093] Specifically, under the condition of determining the closing mode of the upper ball valve, the driving motor controls the oil cylinder to drive the sleeve to move, and the movement of the sleeve drives the wrench to rotate the left and right knobs in the blowout preventer, and the rotation of the left and right knobs controls the closing of the upper ball valve.

[0094] Specifically, the sleeve analysis module determines whether the closing state of the upper ball valve of the blowout preventer is qualified based on the comparison result of the displacement of the sleeve and the preset displacement;

[0095] If the displacement is less than the preset displacement, determining that the closing state of the upper ball valve is unqualified;

[0096] If the displacement is greater than or equal to the preset displacement, it is determined that the closed state of the upper ball valve is qualified.

[0097] In the embodiment of the present invention, the preset displacement value is 190 mm. The preset displacement value is obtained by taking the average value of the displacement rates of several historical upper ball valves in the closed state. However, the above value is not limited to this. Those skilled in the art can also adjust the value according to actual needs.

[0098] During the implementation process, the displacement amount 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.

[0099] In the embodiment of the present invention, the closed state is a closed state in which the upper ball valve and the upper valve seat are just in contact or a closed state in which the upper ball valve and the upper valve seat are in interference fit contact. It can be understood that interference fit contact can be adopted between the valve seat and the ball to improve the initial sealing performance.

[0100] During implementation, when the displacement is equal to the preset displacement, the closed state is that the upper ball valve and the upper valve seat are just in contact. When the displacement is greater than the preset displacement, the closed state is that the upper ball valve and the upper valve seat are in interference fit contact. The interference fit contact allows the sleeve displacement to exceed the range of 0.2mm~0.5mm, preferably 0.3mm, that is, the displacement of the interference fit contact state is 190.2mm~190.5mm.

[0101] Specifically, under the condition that the closing state of the blowout preventer is determined to be unqualified, it is determined that the upper ball valve has failed, and the lower ball valve is manually started in time to prevent the blowout, and the upper ball valve is replaced at the same time.

[0102] Specifically, the sleeve analysis module determines whether the upper ball valve is closed in time based on a comparison result of the formation fluid height between the upper ball valve and the wellhead casing with a preset height, provided that the blowout preventer is in a qualified closed state.

[0103] 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;

[0104] When the height is greater than the preset height, it is determined that the closing timing of the upper ball valve is not timely.

[0105] 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, but the above value is not limited to this. Those skilled in the art can also adjust the value according to actual needs.

[0106] 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 ball valve as the reference point, and is measured by an ultrasonic liquid level sensor installed on the top of the blowout preventer.

[0107] Specifically, the sleeve analysis module determines to adjust the speed of the drive motor according to a comparison result of a preset height to height ratio and a preset ratio under the condition that the closing timing of the upper ball valve is determined to be untimely;

[0108] If the ratio is less than or equal to the preset ratio, it is determined to increase the speed of the drive motor to a corresponding value using a first preset speed adjustment coefficient of 1.05;

[0109] If the ratio is greater than the preset ratio, it is determined to increase the speed of the drive motor to a corresponding value using a second preset speed adjustment coefficient of 1.12;

[0110] The ratio is the ratio of the preset height to the height.

[0111] In the embodiment of the present invention, the preset ratio is 0.55, but the above value is not limited thereto, and those skilled in the art may also adjust the value according to actual needs.

[0112] In an embodiment of the present invention, the increased speed of the drive motor is the product of the speed and the preset speed adjustment coefficient. The preset speed adjustment coefficient includes a first preset speed adjustment coefficient, which has a value of 1.05; a second preset speed adjustment coefficient, which has a value of 1.12. In order to ensure that the adjusted speed meets actual needs, the adjustment range should not be too large, so the adjustment coefficient is set accordingly to control the adjustment range. The speed includes the speeds of the first off mode and the second off mode.

[0113] Specifically, the present invention determines whether the closing state is qualified by comparing the displacement of the sleeve with the preset displacement, and determines whether the closing timing is timely based on the comparison of the formation fluid height with the preset height. The driving motor speed is adjusted accordingly to ensure that the upper ball valve is closed in a timely and effective manner, thereby improving the blowout prevention performance of the blowout preventer and reducing the wear of the blowout preventer.

[0114] Specifically, after the upper ball valve is closed, a wellbore pressure-killing operation is performed on the wellbore, and the wellbore pressure-killing operation is a type of positive circulation wellbore pressure-killing or injection wellbore pressure-killing operation. After the wellbore pressure is successfully killed and the wellbore pressure is stable, the drive motor reversely controls the oil cylinder to drive the sleeve to reset. The sleeve reset drives the wrench to rotate and reset so that the left and right knobs in the blowout preventer rotate. The left and right knobs rotate to control the upper ball valve to open.

[0115] Specifically, the reset analysis module determines whether the upper ball valve is fully opened based on the comparison result of the reset accuracy of the sliding sleeve after the driving motor drives the sliding sleeve to reset and the reset accuracy threshold;

[0116] If the reset accuracy is less than or equal to the reset accuracy threshold, determining that the upper ball valve is fully opened;

[0117] If the reset accuracy is greater than the reset accuracy threshold, it is determined that the upper ball valve is not fully opened.

[0118] In the embodiment of the present invention, the reset accuracy threshold is 0.5%. The reset accuracy threshold is obtained under the condition of maximum reset accuracy when the upper ball valve is fully opened, but the above value is not limited to this. Those skilled in the art can also adjust the value according to actual needs.

[0119] During implementation, the reset accuracy is the ratio of the absolute value of the difference between the displacement of the sleeve after actual reset and the displacement of the sleeve when the upper ball valve is fully closed to the displacement of the sleeve when the upper ball valve is fully closed, multiplied by 100%.

[0120] Specifically, the reset analysis module determines, under the condition that the upper ball valve is not fully opened, to adjust the torque of the drive motor according to a comparison result of the difference between the reset accuracy and the reset accuracy threshold and a preset difference;

[0121] If the difference is less than or equal to the preset difference, determining to increase the speed of the drive motor to a corresponding value using a first preset torque optimization coefficient of 1.10;

[0122] If the difference is greater than the preset difference, it is determined to increase the speed of the drive motor to a corresponding value using a second preset torque optimization coefficient of 1.20;

[0123] The difference is a difference between the reset accuracy and the reset accuracy threshold.

[0124] In the embodiment of the present invention, the preset difference value is 0.05, but the above value is not limited thereto, and those skilled in the art may also adjust the value according to actual needs.

[0125] In an 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, which is 1.10; a second preset torque optimization coefficient, which is 1.20. In order to ensure that the adjusted torque meets actual needs, the adjustment range should not be too large, so the corresponding adjustment coefficient is set to control the adjustment range. The torque includes the torque of the first closing mode and the second closing mode.

[0126] Specifically, the present invention controls the reset of the sleeve by driving the motor in reverse to open the upper ball valve, and determines whether the upper ball valve is fully opened based on the comparison result of the reset accuracy and the reset accuracy threshold, and adjusts the torque of the driving motor accordingly. According to the actual situation of the reset accuracy, the torque of the driving motor is adjusted to optimize the opening effect of the upper ball valve, reduce the risk of accidents caused by improper opening of the upper ball valve, and enhance the safety of the operation.

[0127] See also Figure 4 As shown, it is a flow chart of a method for controlling a blowout preventer in a top drive of a drilling rig according to an embodiment of the present invention.

[0128] In another aspect, the present application also provides a control method of a top drive inner blowout preventer of a drilling rig, comprising:

[0129] In step S1, pressure data of a plurality of monitoring points at a wellhead during a drilling-in process, well fluid return amount, and formation fluid height between a ball valve and the wellhead casing are acquired, and displacement data of a sliding sleeve of the blowout preventer during a single opening and closing process of the blowout preventer are also monitored.

[0130] In step S2, a degree of severity of pressure fluctuation in the well is determined based on a pressure dynamic response parameter of the pressure data, or a degree of severity of well fluid return amount fluctuation in the well is determined based on a flow rate mutation characteristic value of the well fluid return amount.

[0131] In step S3, a degree of severity of blowout is determined based on the degrees of severity of the pressure fluctuation in the well and the well fluid return amount fluctuation in the well, and a closing mode of the ball valve is determined.

[0132] In step S4, whether a closing state of the ball valve of the blowout preventer is qualified is determined based on the displacement amount of the sliding sleeve, whether the closing timing of the ball valve is timely is determined based on the formation fluid height between the ball valve and the wellhead casing, and a rotation speed of a driving motor is adjusted based on a ratio of a preset height to the height.

[0133] In step S5, whether the ball valve is completely opened is determined based on a reset accuracy of the sliding sleeve after the sliding sleeve is reset by the driving motor, and a torque of the driving motor is adjusted based on a difference between the reset accuracy and a reset accuracy threshold.

[0134] So far, the technical solutions of the present application have been described in combination with the preferred embodiments shown in the drawings, but it is easy for those skilled in the art to understand that the protection scope of the present application is obviously not limited to these specific embodiments. Those skilled in the art can make equivalent changes or replacements to related technical features without departing from the principles of the present application, and the technical solutions after these changes or replacements will all fall within the protection scope of the present application.

[0135] The above description is only for the preferred embodiments of the present application and is not used to limit the present application; for those skilled in the art, the present application can have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A control system for a blowout preventer in a top drive of a drilling rig, comprising: The main body includes a plug, left and right knobs, and upper and lower ball valves, which are used to carry the sliding mechanism, driving mechanism, actuator and control mechanism. It is characterized by further comprising: A sliding mechanism, which is used to drive the actuator to move through the driving mechanism; The sliding mechanism includes a sliding sleeve provided on the upper portion of the body for rotating the actuator, a slider provided on the upper portion of the sliding sleeve for connecting the sliding sleeve and a slider, and a slider provided on the upper portion of the slider for driving the sliding sleeve to move up and down; A driving mechanism, comprising an oil cylinder disposed on an upper portion of the sliding mechanism for driving the sliding mechanism; An actuator comprising a wrench rack provided on the body for fixing a wrench, and a wrench provided on the wrench rack for rotating the cock; A control mechanism, which is arranged inside the body, includes: 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, configured to determine the severity of the pressure fluctuation in the well based on the pressure dynamic response parameter of the pressure data, and to determine the severity of the fluctuation of the well fluid return volume based on the return rate mutation characteristic value of the well fluid return volume; a mode determination module connected to the data analysis module, for determining the severity of the blowout based on the severity of the fluctuations in the well pressure and the well fluid return volume, and determining the closing mode of the upper ball valve; a sleeve analysis module connected to the mode determination module, configured to determine whether the upper ball valve of the blowout preventer is closed properly based on the displacement of the sleeve, determine whether the upper ball valve is closed in a timely manner based on the formation fluid height between the upper ball valve and the wellhead casing, and adjust the speed of the drive motor based on the ratio of a preset height to the formation fluid 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 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.

2. The control system for the blowout preventer in the top drive of a drilling rig according to claim 1, 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.

3. The control system for the blowout preventer in the top drive of a drilling rig according to claim 2, characterized in that: The data analysis module determines the severity of the fluctuation of the well fluid return volume according to the comparison result of the return rate mutation characteristic value of the well fluid return volume and the preset return 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 fluctuation of the well fluid return amount in the well is stable; 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 flow amount of the well fluid in the well fluctuates violently.

4. The control system for the blowout preventer in the top drive of a drilling rig according to claim 3, 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 well pressure fluctuations are stable and the well fluid return volume fluctuations are 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 flow of well fluid in the well fluctuates violently, it is determined that the blowout is severe and the closing mode of the ball valve on the blowout preventer is the second closing mode.

5. The control system for the blowout preventer in the top drive of a drilling rig according to claim 4, characterized in that: The sleeve analysis module determines that the upper ball valve is in a qualified closed state based on a comparison result that the displacement of the sleeve is greater than or equal to a preset displacement, and determines that the upper ball valve is not closed in time based on a comparison result that the formation fluid height between the upper ball valve and the wellhead casing is greater than a preset height.

6. The control system for the blowout preventer in the top drive of a drilling rig according to claim 5, characterized in that: The process of adjusting the driving motor speed by the sleeve analysis module when determining that the closing timing of the upper ball valve is not timely includes: Dividing the predetermined height by the formation fluid height; Set 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 rotational speed of the driving motor is set to adjust the rotational speed.

7. The control system for the blowout preventer in the top drive of a drilling rig according to claim 6, 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.

8. The control system for the blowout preventer in the top drive of a drilling rig according to claim 7, characterized in that: The process of adjusting the driving motor torque 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; Set several optimization coefficients corresponding to the corresponding differences; The torque of the drive motor is increased based on the plurality of optimization coefficients.

9. A method for controlling a blowout preventer in a top drive of a drilling rig, using the control system for the blowout preventer in a top drive of a drilling rig according to any one of claims 1 to 8, characterized in that: The control method includes: Obtain pressure data, fluid return volume, and formation fluid height between the upper ball valve and the wellhead casing at several monitoring points at the wellhead during the drilling process. It is also used to monitor the displacement data of the sliding sleeve of the blowout preventer during a single opening and closing process. Determining the severity of the pressure fluctuation in the well based on the pressure dynamic response parameter of the pressure data, and determining the severity of the fluctuation of the well fluid return volume in the well based on the return rate mutation characteristic value of the well fluid return volume; Determine the severity of the blowout based on the severity of the well pressure fluctuations and the well fluid return volume fluctuations, and determine the closing mode of the upper ball valve; determining whether the upper ball valve of the blowout preventer is closed properly based on the displacement of the sliding sleeve, determining whether the upper ball valve is closed in time based on the formation fluid height between the upper ball valve and the wellhead casing, and adjusting the speed of the drive motor based on the ratio of a preset height to the formation fluid height; Whether the upper ball valve is fully opened is determined based on the reset accuracy of the sliding sleeve after the sliding sleeve is reset by the driving motor, 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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